Λύσεις — Κεφάλαιο 8: Heat Engines – VOCATIONAL LANGUAGE LEARNING COURSEBOOK FOR MECHANICAL ENGINEERING TECHNICIANS Β ΕΠΑΛ

VOCATIONAL LANGUAGE LEARNING COURSEBOOK FOR MECHANICAL ENGINEERING TECHNICIANS Β ΕΠΑΛ VOCATIONAL LANGUAGE LEARNING COURSEBOOK FOR MECHANICAL ENGINEERING TECHNICIANS Β ΕΠΑΛ – ΛΥΣΕΙΣ – ΑΠΑΝΤΗΣΕΙΣ Ασκήσεων Σχολικού Βιβλίου Λύσεις — Κεφάλαιο 8: Heat Engines – VOCATIONAL LANGUAGE LEARNING COURSEBOOK FOR MECHANICAL ENGINEERING TECHNICIANS Β ΕΠΑΛ

Λύσεις — Κεφάλαιο 8: Heat Engines

Ενδεικτικές λύσεις των 54 φιλτραρισμένων κλειστών ασκήσεων της ενότητας (σελ. 174-222): θερμικές μηχανές εσωτερικής/εξωτερικής καύσης, δομή βενζινομηχανής (upper/lower engine), κύκλος 4 χρόνων, σύστημα ανάφλεξης, σύστημα καυσίμου (καρμπυρατέρ, ψεκασμός), πετρελαιοκινητήρας, ταξινόμηση κινητήρων, γενική ανακεφαλαίωση 40 ερωτήσεων.

Εισαγωγικό τεστ Σωστό/Λάθος (Introduction)

Ερώτηση: Are the following sentences true (T) or false (F)? 1. Heat engines use mechanical energy to produce heat. 2. Transport and our industrial development are based on heat engines. 3. There are two main categories of heat engines: the internal combustion engines and the external combustion engines. 4. In an internal combustion engine, combustion takes place inside the engine (internally). 5. The most widely used heat engines are the external combustion ones. 6. Nowadays, internal combustion engines have gradually been replaced by external combustion engines and are mostly used in power plants to produce electricity. Read the short text that follows and check your answers.

Απάντηση:

Το σύντομο κείμενο που ακολουθεί (σελ.174) απαντά ρητά: «Heat engines use the energy of heat to produce mechanical energy» (άρα το 1 είναι ανάποδο — ΛΑΘΟΣ)· «Our industrial development is based on them» (2 ΣΩΣΤΟ)· «distinguished into two main categories: the external combustion engines and the internal combustion engines» (3 ΣΩΣΤΟ)· «In an internal combustion engine...combustion takes place inside the engine (internally)» (4 ΣΩΣΤΟ)· το κείμενο δεν λέει πουθενά ότι οι εξωτερικής καύσης είναι οι πιο διαδεδομένες — αντίθετα «since then they have gradually been replaced by diesel engines» (5 ΛΑΘΟΣ)· και είναι οι ΕΞΩΤΕΡΙΚΗΣ καύσης (όχι εσωτερικής) που αντικαταστάθηκαν και τώρα χρησιμοποιούνται σε σταθμούς παραγωγής ενέργειας (6 ΛΑΘΟΣ, τα υποκείμενα είναι ανεστραμμένα).

Σύνοψη: (ενδεικτική) 1. False (χρησιμοποιούν θερμότητα για να παράγουν μηχανική ενέργεια, όχι το αντίστροφο). 2. True. 3. True. 4. True. 5. False (οι εξωτερικής καύσης έχουν σταδιακά αντικατασταθεί). 6. False (οι ΕΞΩΤΕΡΙΚΗΣ καύσης μηχανές αντικαταστάθηκαν από ντιζελομηχανές και τώρα χρησιμοποιούνται κυρίως σε σταθμούς παραγωγής ενέργειας — όχι οι εσωτερικής καύσης).

Κριτήρια αξιολόγησης:

Αντικατάσταση λέξεων με συνώνυμα (Exercises, εισαγωγικό κείμενο)

Ερώτηση: Which words in the text can be replaced by the ones below? to create, classified, to rotate, occurs; happens, aircraft, progressively, progress, to generate.

Απάντηση:

Το εισαγωγικό κείμενο (σελ.174) χρησιμοποιεί: «to produce mechanical energy» (=to create), «to spin the wheels» (=to rotate), «aeroplanes» (=aircraft), «Our industrial development» (=progress), «distinguished into two main categories» (=classified), «combustion takes place» (=occurs; happens), «have gradually been replaced» (=progressively), «to produce electricity» (=to generate).

Σύνοψη: (ενδεικτική) produce (mechanical energy) = to create · spin = to rotate · aeroplanes = aircraft · (industrial) development = progress · distinguished (into) = classified · (combustion) takes place = occurs; happens · gradually = progressively · produce (electricity) = to generate.

Κριτήρια αξιολόγησης:

Ζεύγη αντωνύμων (Exercises, εισαγωγικό κείμενο)

Ερώτηση: Make pairs of antonyms out of the two groups below. A. heat, nowhere, without, easily, internal, outside, gradually. B. external, everywhere, hardly, cold, inside, suddenly, with.

Απάντηση:

Οι λέξεις των δύο στηλών σχηματίζουν 7 ζεύγη αντιθέτων εννοιών, ανεξάρτητα από τη σειρά εμφάνισής τους στις στήλες Α/Β.

Σύνοψη: (ενδεικτική) heat ↔ cold · nowhere ↔ everywhere · without ↔ with · easily ↔ hardly · internal ↔ external · outside ↔ inside · gradually ↔ suddenly.

Κριτήρια αξιολόγησης:

Ελληνικοί όροι τύπων θερμικών μηχανών

Ερώτηση: Below are illustrated some of the most widely used heat engines. Say the equivalent Greek term for each one of them. EXTERNAL COMBUSTION STEAM TURBINE ENGINE. INTERNAL COMBUSTION RECIPROCATING ENGINE. INTERNAL COMBUSTION TURBINE ENGINE. INTERNAL COMBUSTION ROTARY ENGINE (WANKEL). EXTERNAL COMBUSTION RECIPROCATING STEAM ENGINE.

Απάντηση:

Οι πέντε αγγλικοί τεχνικοί όροι δίνονται ρητά ως λεζάντες στο ίδιο το κείμενο (σελ.175)· η μετάφρασή τους βασίζεται στο ήδη εισαγμένο λεξιλόγιο της ενότητας (external/internal combustion, reciprocating, turbine, rotary).

Σύνοψη: (ενδεικτική) External combustion steam turbine engine = ατμοστρόβιλος εξωτερικής καύσης. Internal combustion reciprocating engine = παλινδρομική μηχανή εσωτερικής καύσης. Internal combustion turbine engine = στρόβιλος εσωτερικής καύσης (αεριοστρόβιλος). Internal combustion rotary engine (Wankel) = περιστροφική μηχανή εσωτερικής καύσης (κινητήρας Wankel). External combustion reciprocating steam engine = παλινδρομική ατμομηχανή εξωτερικής καύσης.

Κριτήρια αξιολόγησης:

Ενδεικτική μετάφραση· αποδεκτές ισοδύναμες αποδόσεις.

Πρόσθετες πληροφορίες για τα μέρη του κινητήρα (Additional Information)

Ερώτηση: In the boxes below, you will find some additional information concerning the various parts of an engine. Identify the part of the engine to which the information included in each box refers and fill in the gaps. 1. While flowing through the moving parts of the engine, the oil also absorbs part of the heat produced by combustion, thus cooling the engine. The oil is collected into the . It has a thin casing of pressed steel or cast aluminium, with a large surface area to help release the absorbed heat to the surrounding air. 2. The fill the gap between the pistons and the cylinder wall in order to prevent the pressure of combustion from escaping past the piston. This would cause loss of power. They are made of cast iron or hardened steel. 3. The is driven by the crankshaft by means of a chain, or a rubber belt. It runs at half the crankshaft speed and in most engines, it is used to drive the distributor. 4. One end of the is bolted to the crankshaft. Its other end is connected to the clutch. Its outer edge has gear teeth which are engaged to the starter motor. The starter motor turns the flywheel which, in turn, rotates the crankshaft and starts the engine. 5. The are made from a heat-resisting material, usually high-temperature alloy steel. Their number, arrangement and operation vary greatly depending on the engine type. The greater their number per cylinder, the higher the efficiency of the engine. 6. The piston is linked to the connecting rod via the . This allows the piston to move up and down, while the connecting rod pivots from side to side. 7. When a car is running at maximum speed, each ___ must reciprocate inside the cylinder about a hundred times a second. As a result, pistons must be very strong and at the same time light. To satisfy these demands, pistons in most cars are made of an aluminium alloy.

Απάντηση:

Κάθε κουτί περιγράφει, με λεπτομέρειες ήδη γνωστές από το προηγούμενο κείμενο (upper/lower engine, σελ.176-177), ένα συγκεκριμένο μέρος του κινητήρα: 1→το δοχείο λαδιού στον πάτο του κινητήρα· 2→τα δαχτυλίδια εμβόλου (piston rings, γνωστά ήδη ως «fill the gap...prevent loss of power»)· 3→ο εκκεντροφόρος (camshaft, «driven by the crankshaft...half the crankshaft speed...drives the distributor», ίδιο με το κείμενο TASK2 σελ.177)· 4→ο σφόνδυλος (flywheel, «one end bolted to the crankshaft...connected to the clutch...gear teeth engaged to starter motor»)· 5→οι βαλβίδες (valves, υλικό ανθεκτικό στη θερμότητα, αριθμός ανά κύλινδρο)· 6→ο πείρος εμβόλου (gudgeon pin, συνδέει έμβολο-διωστήρα)· 7→το έμβολο (piston, αλουμινένιο κράμα).

Σύνοψη: (ενδεικτική) 1. oil sump. 2. piston rings. 3. camshaft. 4. flywheel. 5. valves. 6. gudgeon pin. 7. piston.

Κριτήρια αξιολόγησης:

Αγγλικοί όροι για ελληνικές λέξεις (Exercise 1)

Ερώτηση: Write the English equivalent to the following Greek terms. περίβλημα, θήκη, κέλυφος: απώλεια ισχύος: ιμάντας: συμπλέκτης, αμπραγιάζ: σύστημα οδόντων: ροοστάτης κινητήρα, μοτέρ εκκίνησης, μίζα: διάταξη: απόδοση: π(ε)ίρος εμβόλου:

Απάντηση:

Οι όροι αντιστοιχούν σε λέξεις ήδη εισαγμένες στην ενότητα (σελ.176-182): «casing» (oil sump casing), «loss of power», «belt» (rubber belt driving the camshaft), «clutch», «gear teeth», «starter motor», «arrangement», «efficiency», «gudgeon pin».

Σύνοψη: (ενδεικτική) casing · loss of power · belt · clutch · gear teeth · starter motor · arrangement · efficiency · gudgeon pin.

Κριτήρια αξιολόγησης:

Διόρθωση λανθασμένων πληροφοριών (Exercise 2)

Ερώτηση: The information in the sentences below is wrong. Correct it. 1. The valves are made of high-temperature aluminium alloy. 2. The operation of the valves is controlled by the crankshaft. 3. The fewer the valves per cylinder, the higher the efficiency of the engine. 4. The camshaft rotates at double the crankshaft speed and drives the carburettor. 5. Pistons may reciprocate inside the cylinder more than two hundred times a second. 6. Pistons are made of cast iron and have four rings of forged iron each. 7. The piston rings allow the pressure of combustion to escape from the cylinder, to prevent an explosion. 8. The pistons are linked to the connecting rods via the piston rigns. 9. The gudgeon pin allows the piston to rotate while the crankshaft pivots from side to side. 10. To be strong enough, the connecting rods are made of forged aluminium. 11. The gear teeth at the outer edge of the flywheel are engaged to the crankshaft. 12. One side of the flywheel is bolted to the camshaft, and the other is connected to the gear box. 13. Besides lubricating the moving parts of the engine, the oil raises the temperature in the engine to increase its efficiency. 14. The reservoir where the lubricating oil is contained has a thick casing of wrought iron.

Απάντηση:

Κάθε πρόταση αντιστρέφει ή αλλάζει ένα γεγονός ήδη δηλωμένο στο κείμενο (σελ.176-182): οι βαλβίδες είναι από κράμα χάλυβα (όχι αλουμινίου)· τις ελέγχει ο camshaft (όχι ο crankshaft)· ΠΕΡΙΣΣΟΤΕΡΕΣ βαλβίδες = μεγαλύτερη απόδοση· ο camshaft γυρίζει στη ΜΙΣΗ ταχύτητα του crankshaft και κινεί τον distributor (όχι το carburettor)· τα έμβολα κάνουν περίπου 100 (όχι 200+) παλινδρομήσεις/δευτ.· είναι από αλουμινένιο κράμα με ΤΡΙΑ δαχτυλίδια (όχι χυτοσίδηρος με 4)· τα δαχτυλίδια εμβόλου ΕΜΠΟΔΙΖΟΥΝ (όχι επιτρέπουν) τη διαφυγή πίεσης· τα έμβολα συνδέονται με τους διωστήρες μέσω του gudgeon pin (όχι μέσω δαχτυλιδιών)· ο gudgeon pin επιτρέπει στο ΕΜΒΟΛΟ να κινείται πάνω-κάτω ενώ ο ΔΙΩΣΤΗΡΑΣ ταλαντεύεται (όχι ο crankshaft)· οι διωστήρες είναι από σφυρήλατο ΧΑΛΥΒΑ (όχι αλουμίνιο)· τα δόντια είναι στο flywheel και εμπλέκονται με τη ΜΙΖΑ (όχι τον crankshaft)· ο flywheel είναι βιδωμένος στον ΚΡΑΝΚΣΑΦΤ και συνδέεται με τον ΣΥΜΠΛΕΚΤΗ (όχι camshaft/gear box)· το λάδι ΑΠΟΡΡΟΦΑ θερμότητα ΨΥΧΟΝΤΑΣ τον κινητήρα (δεν την αυξάνει)· το δοχείο λαδιού έχει ΛΕΠΤΟ περίβλημα από πρεσαριστό χάλυβα ή χυτό αλουμίνιο (όχι χοντρό από σιδηρόχαλυβα).

Σύνοψη: (ενδεικτική) 1. ...high-temperature alloy STEEL. 2. ...controlled by the CAMSHAFT. 3. The MORE the valves per cylinder, the higher the efficiency. 4. The camshaft rotates at HALF the crankshaft speed and drives the DISTRIBUTOR. 5. Pistons reciprocate ABOUT A HUNDRED times a second. 6. Pistons are made of ALUMINIUM ALLOY and have THREE rings each. 7. The piston rings PREVENT the pressure of combustion from escaping (to avoid loss of power). 8. The pistons are linked to the connecting rods via the GUDGEON PIN. 9. The gudgeon pin allows the PISTON to move up and down while the CONNECTING ROD pivots from side to side. 10. The connecting rods are made of FORGED STEEL. 11. The gear teeth at the outer edge of the flywheel are engaged to the STARTER MOTOR. 12. One side of the flywheel is bolted to the CRANKSHAFT, the other is connected to the CLUTCH. 13. The oil ABSORBS heat, COOLING the engine (does not raise its temperature). 14. The reservoir has a THIN casing of PRESSED STEEL OR CAST ALUMINIUM.

Κριτήρια αξιολόγησης:

Ταύτιση λέξεων-ορισμών, Group A (Exercise 3A)

Ερώτηση: Match words with definitions. GROUP A: 1. casing 2. surrounding 3. to prevent 4. to drive 5. to absorb 6. to release 7. combustion — a. to take measures so as to ensure that something undesirable will not happen b. to take in, e.g. heat, light, knowledge c. process of burning d. being all around e. to allow something to go; to set it free f. covering; protective wrapping g. to supply the power or motion that makes something work or move

Απάντηση:

Οι ορισμοί a-g αντιστοιχούν στις λέξεις 1-7 βάσει της σημασίας τους, όπως ήδη έχουν χρησιμοποιηθεί στα κείμενα της ενότητας (π.χ. «casing» = περίβλημα του oil sump, «combustion» = καύση).

Σύνοψη: (ενδεικτική) 1-f (casing), 2-d (surrounding), 3-a (to prevent), 4-g (to drive), 5-b (to absorb), 6-e (to release), 7-c (combustion).

Κριτήρια αξιολόγησης:

Ταύτιση λέξεων-ορισμών, Group B (Exercise 3B)

Ερώτηση: Match words with definitions. GROUP B: 1. to escape 2. light 3. heat resisting 4. loss 5. to link 6. to bolt 7. to pivot — a. act of losing or having lost something b. to fasten with bolts c. to get or run away from somewhere d. to join; connect; fasten e. not been harmed or affected by heat f. to go round; turn on a central pin or point g. not heavy

Απάντηση:

Οι ορισμοί a-g αντιστοιχούν στις λέξεις 1-7 βάσει της σημασίας τους (π.χ. «to pivot» χρησιμοποιείται ήδη για τον διωστήρα, «to link» για τη σύνδεση εμβόλου-διωστήρα).

Σύνοψη: (ενδεικτική) 1-c (to escape), 2-g (light), 3-e (heat resisting), 4-a (loss), 5-d (to link), 6-b (to bolt), 7-f (to pivot).

Κριτήρια αξιολόγησης:

Συμπλήρωση κενών με λέξεις της Άσκησης 3 (Exercise 4)

Ερώτηση: Choose words from Exercise 3 to fill in the gaps in the sentences below. Put them in the appropriate form. 1. The flywheel the crankshaft to the clutch. 2. To an accident, you must be very careful when working with moving machinery. 3. In a water-cooled car, the water in the radiator heat from the engine and it to the air. 4. According to the of their cylinders, engines are distinguished into various types, such as vee, in-line, radial, etc. 5. As they were carrying it, the motor fell and its cracked. 6. Because of the high temperatures that develop in it, the engine must be made of a material. 7. Steam turbines or reciprocating steam engines are used in power stations to the generators that produce electricity. 8. Thanks to the gudgeon pin, the connecting rod from side to side, thus converting the reciprocating motion of the piston to the rotary motion of the crankshaft. 9. The technician the motor in place with four bolts and nuts on each side. 10. Any of power from the engine decreases its efficiency.

Απάντηση:

Κάθε κενό συμπληρώνεται με λέξη από την Άσκηση 3 (Groups A/B), στην κατάλληλη γραμματική μορφή, με βάση το νόημα της πρότασης.

Σύνοψη: (ενδεικτική) 1. links. 2. prevent. 3. absorbs...releases...surrounding. 4. arrangement (όρος ήδη εισαγμένος στην ενότητα — δες σημείωση). 5. casing. 6. heat-resisting. 7. drive. 8. pivots. 9. bolted/bolts. 10. loss.

Κριτήρια αξιολόγησης:

Το κενό #4 ζητά όρο που περιγράφει τη διάταξη κυλίνδρων (vee/in-line/radial) — η λέξη «arrangement» χρησιμοποιείται ρητά αργότερα στην ίδια ενότητα (σελ.181, item 5 και σελ.215 NOTE 2) αλλά ΔΕΝ περιλαμβάνεται ρητά στη λίστα λέξεων της Άσκησης 3· σημειώνεται ως πιθανή απόκλιση εκφώνησης του βιβλίου.

Fill σε προθέσεις (Exercise 5)

Ερώτηση: Fill in the gaps with the appropriate preposition. Choose from the list: to with on from into of in by means of through. 1. To convert metres millimetres, you must multiply by 1,000. 2. Cylinders may be equipped two, three or four valves each, depending the model. 3. Motion is transferred the crankshaft the clutch the flywheel. 4. I.C.E. can be classified gasoline and diesel engines. 5. Their parents finally succeeded preventing them getting married so young. 6. The casing of the oil sump is usually made pressed steel. 7. Water flows back to the reservoir narrow copper pipes. 8. Diesel engines belong the internal combustion engines.

Απάντηση:

Πρόκειται για σταθερούς προθετικούς συνδυασμούς: convert TO, equipped WITH, depending ON, transferred FROM...THROUGH...BY MEANS OF, classified INTO, succeeded IN...FROM, made OF, THROUGH pipes, belong TO.

Σύνοψη: (ενδεικτική) 1. into. 2. with...on. 3. from...through...by means of. 4. into. 5. in...from. 6. of. 7. through. 8. to.

Κριτήρια αξιολόγησης:

Πρόθεμα trans- (Word Formation, μέρος Α)

Ερώτηση: WORD FORMATION – The prefix trans-. You have often come across words beginning with trans- (e.g. transmit, transfer). A. Choose the correct alternative. trans- = a) far, off b) across, on the other side of, beyond c) in the interior, inside

Απάντηση:

Η σημασία του προθέματος «trans-» (όπως στα «transmit», «transfer», «transport», «translate») είναι «πέρα από, στην άλλη πλευρά», δηλαδή η επιλογή (b).

Σύνοψη: (ενδεικτική) b) across, on the other side of, beyond.

Κριτήρια αξιολόγησης:

Σταυρόλεξο: αγγλικοί τεχνικοί όροι κινητήρα (Crossword)

Ερώτηση: Complete the puzzle with the English equivalent to the Greek terms below. Across: 1. Εξαερωτήρας/καρμπυρατέρ 2. Βαλβίδα 3. Αμπραγιάζ/συμπλέκτης 4. Έμβολο/πιστόνι 5. Μπουζί 6. Στροφαλοφόρος άξονας 7. Διανομέας/ντιστριμπυτέρ. Down: 1. Εκκεντροφόρος άξονας 2. Κύλινδρος 3. Σφόνδυλος/βολάν 4. Διωστήρας/μπιέλα 5. Κιβώτιο ταχυτήτων 6. Λεκάνη.

Απάντηση:

Οι 13 όροι είναι όλοι λέξεις ήδη εισαγμένες στην ενότητα (σελ.176-183): carburettor, valve, clutch, piston, spark plug, crankshaft, distributor, camshaft, cylinder, flywheel, connecting rod, gearbox, oil sump/pan.

Σύνοψη: (ενδεικτική) Across: 1. carburettor, 2. valve, 3. clutch, 4. piston, 5. spark plug, 6. crankshaft, 7. distributor. Down: 1. camshaft, 2. cylinder, 3. flywheel, 4. connecting rod, 5. gearbox, 6. sump.

Κριτήρια αξιολόγησης:

Η λύση δίνει τους αγγλικούς όρους ανεξάρτητα από το πλέγμα του σταυρόλεξου (αριθμός γραμμάτων/διασταυρώσεις), καθώς αυτό δεν είναι διαθέσιμο σε μορφή κειμένου.

Αναγνώριση και σειρά των 4 χρόνων (TASK)

Ερώτηση: The four paragraphs below describe the function of the four strokes in a 4 stroke engine. Read them, identify the stroke described in each paragraph and write it as a heading in the space provided. Also, number the paragraphs in the order the strokes take place. Paragraph A: Both valves remain closed. The piston moves up compressing the fuel/air mixture in the combustion chamber, while at the same time the heat produced by the compression fully vaporizes the mixture. Paragraph B: The inlet valve remains shut. The exhaust valve opens and the piston rises to expel the burnt gases from the cylinder through the exhaust port, manifold and pipe. As soon as the piston reaches the top of its stroke, the exhaust valve closes while the intake opens again to let the new fuel/air mixture enter the cylinder. So, the cycle restarts with another induction stroke. Paragraph C: The inlet valve opens. Driven by the crankshaft, the piston moves down sucking in the engine a mixture of fuel and air from the carburettor. The mixture enters the cylinder travelling through the inlet manifold and port, past the open intake valve. As soon as the piston reaches the bottom of its stroke, the inlet valve closes again driven by the camshaft. During this stroke the exhaust valve remains closed. Paragraph D: Both valves are shut. Just before the piston reaches the Top Dead Centre (TDC), that is the top of its stroke, a spark from the spark plug, which is fitted at the top of the cylinder head, ignites the mixture and combustion takes place. The expansion of the burning gases drives the piston down again and rotates the crankshaft half a turn.

Απάντηση:

Κάθε παράγραφος περιγράφει έναν χρόνο βάσει ρητών λεπτομερειών ήδη γνωστών από την ενότητα: Α — «Both valves...closed...piston moves up compressing» = συμπίεση· Β — «exhaust valve opens...piston rises to expel burnt gases» = εξαγωγή· Γ — «inlet valve opens...piston moves down sucking in...mixture» = εισαγωγή· Δ — «spark...ignites...expansion...drives the piston down» = ισχύς. Η φυσική σειρά του κύκλου είναι εισαγωγή→συμπίεση→ισχύς→εξαγωγή.

Σύνοψη: (ενδεικτική) A = Compression stroke (2η θέση). B = Exhaust stroke (4η θέση). C = Induction stroke (1η θέση). D = Power stroke (3η θέση). Σειρά: Induction (C) → Compression (A) → Power (D) → Exhaust (B).

Κριτήρια αξιολόγησης:

Ελληνικοί-Αγγλικοί όροι κύκλου 4 χρόνων (Exercise 1)

Ερώτηση: Match the Greek terms with their English equivalent. 1. χρόνος εισαγωγής 2. χρόνος συμπίεσης 3. χρόνος καύσης-εκτόνωσης 4. χρόνος εξαγωγής 5. συλλέκτης 6. θάλαμος καύσης 7. καυσαέρια 8. διαστολή, εκτόνωση 9. ανάφλεξη — a. exhaust stroke b. combustion chamber c. induction stroke d. burnt gases e. power stroke f. ignition g. expansion h. manifold i. compression stroke

Απάντηση:

Οι όροι έχουν ήδη εισαχθεί στο κείμενο του κύκλου 4 χρόνων (σελ.187-188): induction/compression/power/exhaust stroke, manifold, combustion chamber, burnt gases, expansion, ignition.

Σύνοψη: (ενδεικτική) 1-c (induction stroke), 2-i (compression stroke), 3-e (power stroke), 4-a (exhaust stroke), 5-h (manifold), 6-b (combustion chamber), 7-d (burnt gases), 8-g (expansion), 9-f (ignition).

Κριτήρια αξιολόγησης:

Εναλλακτικές εκφράσεις κύκλου 4 χρόνων (Exercise 2)

Ερώτηση: Look through the text to find alternative expressions to the following. Write them in the spaces provided. 1. Intake / manifold, port, valve 2. Outlet / manifold, port, valve 3. Intake / stroke 4. Combustion / stroke

Απάντηση:

Το κείμενο (σελ.187-188) χρησιμοποιεί «inlet» ως συνώνυμο του «intake» (inlet valve/manifold/port), «exhaust» ως συνώνυμο του «outlet», «induction stroke» ως συνώνυμο του «intake stroke», και «power stroke» ως τον χρόνο όπου γίνεται η καύση.

Σύνοψη: (ενδεικτική) 1. Intake = inlet (manifold, port, valve). 2. Outlet = exhaust (manifold, port, valve). 3. Intake stroke = induction stroke. 4. Combustion stroke = power stroke.

Κριτήρια αξιολόγησης:

Ερωτήσεις κατανόησης κύκλου 4 χρόνων (Exercise 3)

Ερώτηση: Answer the questions. 1. What is produced every four (2 downward and 2 upward) movements of the piston? 2. Is gasoline alone drawn into the combustion chamber? 3. Why does the inlet valve open in the induction stroke? 4. Where and how is the fuel/air mixture fully vaporized? 5. What is the T.D.C.? 6. In which part of the cylinder is the fuel/air mixture ignited? 7. Is the fuel self-ignited in a gasoline engine? 8. How is the piston driven down after ignition? 9. How are the burnt gases expelled from the cylinder? 10. What does the term «firing order» mean?

Απάντηση:

Οι απαντήσεις προκύπτουν άμεσα από το κείμενο του κύκλου 4 χρόνων (σελ.187-188) και το «Do you know this?» για το firing order.

Σύνοψη: (ενδεικτική) 1. One pulse of power. 2. No, a mixture of fuel and air (not gasoline alone). 3. To let the fuel/air mixture enter the cylinder. 4. In the combustion chamber, during the compression stroke, by the heat produced by compression. 5. Top Dead Centre — the top of the piston's stroke. 6. In the combustion chamber, at the top of the cylinder head. 7. No, it is ignited by a spark from the spark plug. 8. By the expansion of the burning gases pushing it down. 9. The exhaust valve opens and the rising piston pushes them out through the exhaust port, manifold and pipe. 10. The order in which the cylinders of a multi-cylinder engine fire (e.g. 1-2-4-3 or 1-3-4-2 in a four-cylinder engine), chosen to reduce stress and vibration.

Κριτήρια αξιολόγησης:

Συμπλήρωση πληροφορίας για τον κύκλο (Exercise 4)

Ερώτηση: Complete the missing information. 1. To enter the cylinder, the fuel/air mixture starts from the and travels . 2. To get out of the car, the burnt gases pass . 3. The piston moves down during the and up during the . 4. Both valves are closed during the . 5. The inlet valve is open and the exhaust closed . 6. On the exhaust stroke the valve is , while the valve is . 7. When the gases are heated, they expand and .

Απάντηση:

Οι απαντήσεις βασίζονται στο κείμενο του κύκλου 4 χρόνων (σελ.187-188): η διαδρομή μείγματος (carburettor→inlet manifold/port→cylinder), η διαδρομή καυσαερίων (exhaust port→manifold→pipe), η κίνηση εμβόλου ανά χρόνο, οι θέσεις βαλβίδων ανά χρόνο.

Σύνοψη: (ενδεικτική) 1. ...starts from the carburettor and travels through the inlet manifold and port. 2. ...pass through the exhaust port, manifold and pipe. 3. Moves down during the induction and power strokes, up during the compression and exhaust strokes. 4. Both valves closed during the compression and power strokes. 5. Inlet open/exhaust closed during the induction stroke. 6. On the exhaust stroke the exhaust valve is open, while the inlet valve is closed. 7. When heated, gases expand and drive the piston down / push out of the cylinder.

Κριτήρια αξιολόγησης:

Λέξεις-κλειδιά από το κείμενο (Exercise 6)

Ερώτηση: Look through the text to find the words which mean: 1. to draw into: 2. to press something so that it takes less space: 3. to convert a liquid into a gas: 4. a flash of light: 5. fixed, located: 6. to take fire and start burning: 7. to move upward, to reach a higher level or position: 8. to send out or away by force:

Απάντηση:

Οι λέξεις εντοπίζονται στο κείμενο του κύκλου 4 χρόνων (σελ.187-188): «suck in» (draw), «compress», «vaporize», «spark» (flash of light), «fitted» (fixed), «ignite», «rise/rises», «expel».

Σύνοψη: (ενδεικτική) 1. suck in / draw in. 2. compress. 3. vaporize. 4. spark. 5. fitted. 6. ignite. 7. rise. 8. expel.

Κριτήρια αξιολόγησης:

Συμπλήρωση κενών με λέξεις της Άσκησης 6 (Exercise 7)

Ερώτηση: Use words from Exercise 6 to fill in the gaps in the sentences below. Make any necessary changes. 1. After what he did, I wasn't surprised to hear that John was from school. 2. A cigarette thrown from a car window is enough to dry leaves and grass and start a fire in the forest. 3. are produced when striking hard metal and stone. 4. When the piston slides down on the induction stroke, it air and fuel in the cylinder. 5. When water is heated over 100°C, it and becomes steam. 6. Prices will soon again. 7. When the piston moves up on the compression stroke, it the fuel/air mixture in the combustion chamber. 8. Three rings are on the upper part of the piston.

Απάντηση:

Κάθε κενό συμπληρώνεται με λέξη της Άσκησης 6 στην κατάλληλη μορφή.

Σύνοψη: (ενδεικτική) 1. expelled. 2. ignite. 3. Sparks. 4. sucks in / draws in. 5. vaporizes. 6. rise. 7. compresses. 8. fitted.

Κριτήρια αξιολόγησης:

Δείκτες χρόνου στην περιγραφή του κύκλου (Showing Time Relationships)

Ερώτηση: Choose time markers from the list to fill in the gaps in the text: During, At the time, Then, Immediately after that, As soon as, Next, At the same time, While, First, Following, At exactly the moment. (1) the inlet valve opens. (2), the piston starts sliding down. (3) its downward movement fuel and air mixture is drawn from the carburettor into the cylinder. (4) the piston completes this stroke, the inlet valve is closed. The piston (5), starts rising, thus compressing the fuel/air mixture in the cylinder. (6) that the piston is at the top of its stroke, the mixture is ignited by a spark from the spark plug, and combustion takes place. (7) the compression and combustion strokes, both valves remain shut. (8), the piston moves down again driven by the expanded gases. (9), the exhaust valve opens and the piston starts rising once more, driven by the crankshaft. (10) the piston is rising, it pushes the burnt gases out of the cylinder. (11) that the piston reaches the top of its stroke, the exhaust valve is closed while the inlet opens again.

Απάντηση:

Η σειρά των δεικτών χρόνου ακολουθεί λογικά τη χρονική αλληλουχία του κύκλου 4 χρόνων, όπως ήδη περιγράφηκε στο κείμενο των σελ.187-188.

Σύνοψη: (ενδεικτική) (1) First. (2) At the same time. (3) During. (4) As soon as. (5) then / next. (6) At exactly the moment. (7) During. (8) Immediately after that. (9) Next / Then. (10) While. (11) As soon as.

Κριτήρια αξιολόγησης:

Ενδεικτική σειρά δεικτών — αρκετά κενά δέχονται περισσότερους από έναν σωστό δείκτη χρόνου (π.χ. Then/Next), αρκεί να τηρείται η σωστή χρονική αλληλουχία.

Αγγλικοί-Ελληνικοί τεχνικοί όροι συστήματος ανάφλεξης (TASK 3)

Ερώτηση: Look through the text and complete the table below with the missing Greek or English term. ignition coil / (μετασχηματιστής ανόδου τάσης). Alternating current (AC) / . (Συνεχές ρεύμα). high tension/voltage / (χαμηλή τάση). contact breaker / (σημεία επαφής πλατινών). (ράουλο διανομέα). electric circuit / . cable / (μόνωση).

Απάντηση:

Οι όροι προκύπτουν από το κείμενο περιγραφής του συστήματος ανάφλεξης (TASK 2, σελ.193): «ignition coil is a step-up pulse transformer», «12V low-tension DC current», «high-tension A.C. current», «the contact breaker... breaker points», «the distributor rotor arm», «H.T. flexible cable with thick plastic insulation», «central circuit».

Σύνοψη: (ενδεικτική) ignition coil = πηνίο ανάφλεξης (step-up pulse transformer = μετασχηματιστής ανόδου τάσης). Alternating current (AC) = εναλλασσόμενο ρεύμα. Direct current (DC) = συνεχές ρεύμα. high tension/voltage = υψηλή τάση (low tension/voltage = χαμηλή τάση). contact breaker = διακόπτης επαφής/πλατίνες (breaker points = σημεία επαφής πλατινών). distributor rotor arm = ράουλο διανομέα. electric circuit = ηλεκτρικό κύκλωμα. cable = καλώδιο (insulation = μόνωση).

Κριτήρια αξιολόγησης:

Ερωτήσεις κατανόησης για το σύστημα ανάφλεξης (FOLLOW UP 1)

Ερώτηση: Answer the questions. 1. What is the usefulness of the ignition system in a car's engine? 2. Into which part of the ignition system is the low-voltage current changed into a high-voltage one? 3. What is the function of the contact breaker? 4. How is the H.T. current distributed to the spark plugs? 5. Why do you think the cables connecting the distributor to the coil, and the spark plugs to the distributor have a thick insulation?

Απάντηση:

Οι απαντήσεις προκύπτουν άμεσα από το γραπτό κείμενο περιγραφής του συστήματος ανάφλεξης (σελ.193).

Σύνοψη: (ενδεικτική) 1. To provide the high-voltage sparks which ignite the fuel/air mixture in the cylinders. 2. In the ignition coil. 3. It produces pulses of electric current by interrupting the circuit, generating high-voltage current in the coil. 4. Through the rotor arm in the distributor cup, driven by the camshaft, which distributes the current to each spark plug in the correct firing order through insulated H.T. cables. 5. Because they carry very high-voltage current (over 10,000V), and thick insulation is needed to prevent the current from leaking/arcing and to protect against electric shock.

Κριτήρια αξιολόγησης:

Συνώνυμα λεξιλογίου συστήματος ανάφλεξης (FOLLOW UP 2)

Ερώτηση: Make pairs of synonyms. Group A: provide, convert, consist, required, mainly, achieve, in fact, fit, generate, great, quickly, previously, correct, firmly. Group B: basically, indeed, needed, obtain; succeed, change, comprise, supply; give, fast; rapidly, before, right; appropriate, large, securely, fix, produce.

Απάντηση:

Κάθε λέξη της Group A ταιριάζει με το συνώνυμό της στη Group B βάσει σημασίας, όπως χρησιμοποιούνται στο κείμενο του συστήματος ανάφλεξης (π.χ. «provide/supply», «convert/change», «achieve...with the help of»).

Σύνοψη: (ενδεικτική) provide = supply;give. convert = change. consist = comprise. required = needed. mainly = basically. achieve = obtain;succeed. in fact = indeed. fit = right;appropriate. generate = produce. great = large. quickly = fast;rapidly. previously = before. correct = fix. firmly = securely.

Κριτήρια αξιολόγησης:

Συμπλήρωση κειμένου λειτουργίας ανάφλεξης (FOLLOW UP)

Ερώτηση: Complete the text taking your information from the table below. Missing information: a) the contact breaker points are opened b) to the spark plug's centre electrode c) through the HT cable that connects the coil to the distributor d) driven by the crankshaft e) connected to the same cylinder's spark plug f) driven by the camshaft. As the starter motor turns the engine, one of the pistons, (1), rises to compress the fuel/air mixture at the top of its cylinder. At the same time, the shaft in the distributor, (2), turns so that the rotor arm points at the HT cable which is (3). Just before the piston reaches the TDC, (4) creating a high voltage in the ignition coil. The HT current flows (5), passes across the rotor arm and, along the plug's HT cable, flows (6) to produce the spark.

Απάντηση:

Κάθε κενό ταιριάζει με ΜΙΑ από τις 6 δοσμένες φράσεις a-f, βάσει της λογικής αλληλουχίας λειτουργίας του συστήματος ανάφλεξης όπως περιγράφεται στο κείμενο της σελ.193 (πιστόνι κινείται από στροφαλοφόρο, άξονας διανομέα από εκκεντροφόρο, HT καλώδιο συνδέει πηνίο-διανομέα, breaker points ανοίγουν δημιουργώντας τάση, ρεύμα φτάνει στο κέντρο ηλεκτρόδιο μπουζί).

Σύνοψη: (ενδεικτική) (1) d — driven by the crankshaft. (2) f — driven by the camshaft. (3) e — connected to the same cylinder's spark plug. (4) a — the contact breaker points are opened. (5) c — through the HT cable that connects the coil to the distributor. (6) b — to the spark plug's centre electrode.

Κριτήρια αξιολόγησης:

Ερωτήσεις πριν την ανάγνωση: σύστημα καυσίμου (PRE-QUESTIONS)

Ερώτηση: Read the short text below and answer the questions. 1. What is the function of the fuel system? 2. Which factors determine the precise ratio of fuel and air needed by the engine? 3. In which part of the engine are fuel and air mixed in the appropriate proportions?

Απάντηση:

Οι απαντήσεις δίνονται ρητά στο κείμενο που ακολουθεί (σελ.198): «To produce combustion, an I.C.E. needs not only fuel but also air», «The precise ratio of fuel and air needed depends on a number of factors which are related to the engine's running conditions», «The part of the engine where gasoline and air are mixed in the correct proportions... is the carburettor».

Σύνοψη: (ενδεικτική) 1. To supply the engine with the correct fuel/air mixture needed for combustion. 2. The engine's running conditions (e.g. steady load, cold starting, hard acceleration, idling). 3. In the carburettor.

Κριτήρια αξιολόγησης:

Οδηγικές συνθήκες και λόγος μείγματος (Exercise 1)

Ερώτηση: Match the two columns. Driving situations: 1. The driver wants to pass by another car, which is moving at almost the same speed, so he starts speeding up. 2. The car has been running at almost the same speed for many kilometres. 3. The driver is waiting for an old man to cross the road with the engine running. 4. Early in a cold winter morning, the driver turns the ignition switch and the engine starts running. — Engine's running conditions: a. steady load conditions b. cold starting c. hard acceleration d. (the engine is) idling

Απάντηση:

Κάθε οδηγική κατάσταση αντιστοιχεί σε μία από τις 4 συνθήκες λειτουργίας που ήδη περιγράφηκαν στο κείμενο της σελ.198 (steady load, cold starting, hard acceleration, idling).

Σύνοψη: (ενδεικτική) 1-c (hard acceleration), 2-a (steady load conditions), 3-d (idling), 4-b (cold starting).

Κριτήρια αξιολόγησης:

Διόρθωση λανθασμένων πληροφοριών (Exercise 2)

Ερώτηση: Correct the wrong information in the sentences below. 1. To produce combustion, an I.C.E. needs only gasoline. 2. The precise ratio of fuel and air needed depends on the weather and the temperature of the surrounding air. 3. For a cold starting, the engine needs a very weak fuel/air mixture. 4. When the engine is idling, it needs a richer fuel/air mixture than when it is running under steady load conditions. 5. An over-weak fuel/air mixture increases the engine's output.

Απάντηση:

Κάθε πρόταση αντιστρέφει γεγονός του κειμένου (σελ.198): χρειάζεται και αέρα (όχι μόνο βενζίνη)· ο λόγος εξαρτάται από τις συνθήκες λειτουργίας (όχι τον καιρό)· στο κρύο ξεκίνημα χρειάζεται πλουσιότερο (όχι πιο φτωχό) μείγμα· στο ρελαντί χρειάζεται πιο φτωχό (όχι πιο πλούσιο) μείγμα από ό,τι σε σταθερό φορτίο· το υπερβολικά φτωχό μείγμα ΜΕΙΩΝΕΙ (δεν αυξάνει) την απόδοση.

Σύνοψη: (ενδεικτική) 1. ...needs not only gasoline but also air. 2. ...depends on the engine's running conditions (not the weather). 3. For a cold starting, the engine needs a RICHER fuel/air mixture. 4. When idling, the engine needs a WEAKER mixture than under steady load conditions. 5. An over-weak fuel/air mixture REDUCES the engine's output and efficiency.

Κριτήρια αξιολόγησης:

Διάταξη συνθηκών λειτουργίας κατά λόγο μείγματος (Exercise 3)

Ερώτηση: Arrange the engine's running conditions according to the f/a mixture ratio they require. 1. (rich mixture) 2. 3. 4. (weak mixture)

Απάντηση:

Το κείμενο δίνει ρητούς λόγους μείγματος: cold starting έως 1:1 (πλουσιότερο), hard acceleration 12:1, steady load conditions ~15:1, idling το πιο φτωχό — άρα η σειρά από το πιο πλούσιο στο πιο φτωχό είναι: cold starting, hard acceleration, steady load conditions, idling.

Σύνοψη: (ενδεικτική) 1. Cold starting (richest, up to 1:1). 2. Hard acceleration (12:1). 3. Steady load conditions (~15:1). 4. Idling (weakest mixture).

Κριτήρια αξιολόγησης:

Λέξεις-κλειδιά για το σύστημα καυσίμου (Exercise 4)

Ερώτηση: Look through the text to find the words which mean: 1. a material that is burned to provide heat or power: 2. exact; definite; accurate: 3. how much of each material there is in a mixture; the relationship between the amounts of the two materials/their proportion in it: 4. a situation without interruptions or changes: 5. for example: 6. increase of speed; getting faster and faster: 7. the engine is running slowly and quietly because it is not in gear, and the car is not moving: 8. not strong, powerful or effective:

Απάντηση:

Οι λέξεις εντοπίζονται στο κείμενο της σελ.198: «fuel», «precise», «ratio», «steady», «for instance», «acceleration», «idling», «weak».

Σύνοψη: (ενδεικτική) 1. fuel. 2. precise. 3. ratio. 4. steady. 5. for instance. 6. acceleration. 7. idling. 8. weak.

Κριτήρια αξιολόγησης:

Ερωτήσεις πριν την ανάγνωση: καρμπυρατέρ (PRE-QUESTIONS)

Ερώτηση: The text which follows describes how a carburettor operates. Read it and answer the questions below. 1. On which strokes does the engine suck air? 2. What is the «carburettor barrel»? 3. What is the «venturi» in a carburettor, and how does it function? 4. How is the speed of the car controlled?

Απάντηση:

Οι απαντήσεις δίνονται ρητά στο κείμενο που ακολουθεί (σελ.200-201): «The air drawn into the engine on the induction strokes...», «the main bore of the carburettor, known as the carburettor barrel», «this narrow part is called the venturi. When the air flow...meets the venturi, it speeds up creating a slight vacuum», «the car's speed is regulated by...the throttle valve».

Σύνοψη: (ενδεικτική) 1. On the induction strokes. 2. The main bore (tube) of the carburettor through which air is drawn into the engine. 3. The venturi is the narrow part of the carburettor barrel; when air speeds up passing through it, it creates a slight vacuum that draws petrol into the air stream. 4. By the throttle valve (connected to the accelerator pedal), which controls the amount of fuel/air mixture drawn into the engine.

Κριτήρια αξιολόγησης:

Συμπλήρωση διαγράμματος λειτουργίας καρμπυρατέρ (Exercise 2)

Ερώτηση: Complete the missing information in the diagram below. Gasoline from the ft is pumped to the fc. On the i strokes, air is drawn into the cb. When the air meets the v, it speeds up and a v is created. Atmospheric pressure forces the f from the fc through the j into the b. The f vaporises and is mixed with the a.

Απάντηση:

Κάθε κενό αντιστοιχεί σε λέξη ήδη εισαγμένη στο κείμενο λειτουργίας του καρμπυρατέρ (σελ.200-201): fuel tank, float chamber, induction strokes, carburettor barrel, venturi, vacuum, jet, barrel, air.

Σύνοψη: (ενδεικτική) Gasoline from the FUEL TANK is pumped to the FLOAT CHAMBER. On the INDUCTION strokes, air is drawn into the CARBURETTOR BARREL. When the air meets the VENTURI, it speeds up and a VACUUM is created. Atmospheric pressure forces the FUEL from the FLOAT CHAMBER through the JET into the BARREL. The FUEL vaporises and is mixed with the AIR.

Κριτήρια αξιολόγησης:

Σωστό/Λάθος για τη λειτουργία του καρμπυρατέρ (Exercise 3)

Ερώτηση: Are the following statements true or false? Correct the false ones. 1. The main bore of the carburettor, known as «carburettor barrel», is, in fact, a tube of large diameter. 2. Gasoline is pumped from the float chamber to the fuel tank, which is a reservoir in the carburettor assembly. 3. Before the venturi, a mixture of gasoline and air flows through the carburettor barrel; after the venturi, only gasoline flows through it (the barrel). 4. The vacuum created as the incoming air meets the venturi draws fuel from the float chamber in the carburettor barrel. 5. Air enters the carburettor barrel flowing through a narrow tube called «jet». 6. When the fuel meets the air stream flowing through the barrel, it is broken down into tiny droplets. 7. The speed of a car is controlled by the amount of air drawn into the engine, which is regulated by the throttle. 8. As the driver steps on the accelerator pedal, the throttle lets more fuel/air mixture pass into the engine.

Απάντηση:

Κάθε statement διασταυρώνεται με το κείμενο λειτουργίας καρμπυρατέρ (σελ.200-201): ο κύλινδρος του καρμπυρατέρ ΔΕΝ είναι σταθερής μεγάλης διαμέτρου (στενεύει στο venturi)· η βενζίνη αντλείται ΑΠΟ τη δεξαμενή ΣΤΟΝ float chamber (όχι αντίστροφα, και η δεξαμενή καυσίμου δεν είναι μέρος του καρμπυρατέρ)· ΜΟΝΟ αέρας (όχι μείγμα) περνά πριν το venturi, το καύσιμο μπαίνει ΣΤΟ venturi· το κενό τραβά καύσιμο (σωστό)· ο jet είναι για το ΚΑΥΣΙΜΟ, όχι τον αέρα· το καύσιμο θρυμματίζεται σε σταγονίδια (σωστό)· η ταχύτητα ρυθμίζεται από την ποσότητα ΜΕΙΓΜΑΤΟΣ (όχι μόνο αέρα)· το γκάζι επιτρέπει περισσότερο μείγμα (σωστό).

Σύνοψη: (ενδεικτική) 1. False — it is a tube whose diameter is REDUCED at one point (the venturi), not uniformly large. 2. False — gasoline is pumped FROM the fuel tank TO the float chamber, which is a small reservoir IN the carburettor assembly. 3. False — a mixture of air (not gasoline+air) flows before the venturi; gasoline is drawn in AT the venturi, and afterwards the fuel/air mixture flows through the barrel. 4. True. 5. False — FUEL (not air) enters through the jet. 6. True. 7. False — controlled by the amount of fuel/air MIXTURE, regulated by the throttle. 8. True.

Κριτήρια αξιολόγησης:

Λέξεις-κλειδιά για το καρμπυρατέρ (Exercise 4)

Ερώτηση: Find words in the text which mean: 1. to draw in: 2. space completely empty, from which the air has been drawn out: 3. something made up of various parts put together: 4. continuous flow of liquid, persons, things: 5. a very small amount of liquid that looks like a little ball; a very small drop: 6. to control systematically; to adjust a mechanism so as to get the desired result: 7. effort:

Απάντηση:

Οι λέξεις εντοπίζονται στο κείμενο λειτουργίας καρμπυρατέρ (σελ.200-201): «draws» (draw in), «vacuum», «assembly», «stream», «droplet», «regulated», «attempt».

Σύνοψη: (ενδεικτική) 1. draw(s). 2. vacuum. 3. assembly. 4. stream. 5. droplet. 6. regulate. 7. attempt.

Κριτήρια αξιολόγησης:

Αναγνώριση τύπων καρμπυρατέρ (Exercise 5)

Ερώτηση: Identify the carburettor types by their characteristics. 1. It consists of one float chamber but two barrels side by side in one assembly: 2. In order to provide the engine with the appropriate fuel/air mixture for every running condition, it has many jets and circuits, and, as a result, it is very complicated: 3. Every single cylinder is served by a separate carburettor. The inlet manifolds of these carburettors are less complicated, while the equal supply of all cylinders with fuel is ensured: 4. Although it has only one jet, it can supply the engine with the appropriate f/a mixture by changing the size of the venturi according to the air flow:

Απάντηση:

Κάθε περιγραφή αντιστοιχεί ρητά σε έναν από τους τύπους καρμπυρατέρ που περιγράφονται στις σελ.201-202: fixed jet (πολλά jet/circuits, περίπλοκο), variable choke (ένα jet, μεταβλητό venturi), multiple carburettors (ένα ανά κύλινδρο), compound twin-choke (δύο κύλινδροι/ένα float chamber).

Σύνοψη: (ενδεικτική) 1. Compound twin-choke carburettor. 2. Fixed jet carburettor. 3. Multiple carburettors. 4. Variable choke carburettor.

Κριτήρια αξιολόγησης:

Ομαδοποίηση λέξεων κατά σημασία (Exercise 6)

Ερώτηση: Arrange the following words in groups according to their meaning. Words: appropriate, control, constant, located, drilling, miniature, tube, precise, combine, jet, fixed, microscopic, fitted, link, small, accurate, unchanged, fix, reservoir, pipe, correct, continuous, positioned, adjust, little, tank, join, placed, hole. Headings: bore, tiny, mounted, exact, steady, connect, regulate, container.

Απάντηση:

Κάθε λέξη ταιριάζει σημασιολογικά με μία από τις 8 επικεφαλίδες: «bore» = σωλήνας/άνοιγμα δίοδος, «tiny» = πολύ μικρό, «mounted» = στερεωμένο σε θέση, «exact» = ακριβές, «steady» = σταθερό/αμετάβλητο, «connect» = συνδέω, «regulate» = ελέγχω/ρυθμίζω, «container» = δοχείο.

Σύνοψη: (ενδεικτική) bore: drilling, tube, pipe, hole, jet. tiny: miniature, microscopic, small, little. mounted: fixed, fitted, positioned, placed, located. exact: precise, accurate, correct, appropriate. steady: constant, unchanged, continuous. connect: combine, link, join. regulate: control, adjust, fix. container: reservoir, tank.

Κριτήρια αξιολόγησης:

Ελληνικοί-Αγγλικοί όροι συστήματος ψεκασμού (Exercise 1)

Ερώτηση: Below are the Greek terms for the main parts of a fuel injection system. Write their English equivalent. 1. Μονάδα ελέγχου 2. Πεντάλι γκαζιού 3. Δοχείο βενζίνης 4. Σωλήνες/γραμμές διέλευσης καυσίμου 5. Εγχυτήρας/μπεκ 6. Ρυθμιστής πίεσης καυσίμου 7. Φίλτρο αέρα 8. Αισθητήρες 9. Φίλτρο καυσίμου 10. Ηλεκτρική αντλία βενζίνης 11. Εμφρακτική βαλβίδα/πεταλούδα

Απάντηση:

Οι όροι είναι ήδη εισαγμένοι στο κείμενο/διάγραμμα ψεκασμού (σελ.205-206): control unit, accelerator, fuel tank, fuel lines, injector, fuel-pressure regulator, air filter, sensors, fuel filter, electric fuel pump, throttle valve.

Σύνοψη: (ενδεικτική) 1. (electronic) control unit. 2. accelerator (pedal). 3. fuel tank. 4. fuel lines. 5. injector. 6. fuel-pressure regulator. 7. air filter. 8. sensors. 9. fuel filter. 10. electric fuel pump. 11. throttle valve.

Κριτήρια αξιολόγησης:

Ερωτήσεις κατανόησης για το σύστημα ψεκασμού (Exercise 3)

Ερώτηση: Answer the questions. 1. What is the advantage of fuel injection over the conventional fuel systems? 2. Which types of fuel injection are mentioned in the text? 3. Do cars equipped with fuel injection have carburettors? 4. How does the fuel enter the engine in cars equipped with a fuel injection system? 5. Where is the fuel mixed with air in these cars? 6. What happens when the gasoline is sprayed by the injectors? 7. How is the injection of fuel controlled in cars with electronic fuel injection? 8. What is the use of the fuel pump and the fuel regulator?

Απάντηση:

Οι απαντήσεις δίνονται ρητά στο κείμενο ψεκασμού καυσίμου (σελ.205-206).

Σύνοψη: (ενδεικτική) 1. It saves fuel and reduces air pollution by providing exactly the correct fuel/air proportion for every running condition. 2. Mechanical and electronic fuel injection. 3. No, they have injectors instead of carburettors. 4. Injectors forcibly spray fuel directly into the inlet manifold, inlet port or the cylinder. 5. In the inlet manifold/port or in the cylinder itself, depending on the system. 6. It is atomized (broken into mistlike droplets) which readily mix with the incoming air. 7. By an electronic control unit (a computer) connected to sensors that monitor the engine's functions. 8. The fuel pump provides the pressure needed to send gasoline from the tank to the injectors; the fuel-pressure regulator limits the pressure in the fuel lines.

Κριτήρια αξιολόγησης:

Λέξεις που αντικαθιστούν φράσεις (Exercise 4)

Ερώτηση: Look through the text to find the words that can be replaced by the following: 1. to use, spend, consume less: 2. which have; having: 3. strongly; powerfully: 4. straightly; immediately: 5. flows quickly: 6. easily; quickly, without difficulty: 7. constantly: 8. provide: 9. reduces; lessens: 10. pipes:

Απάντηση:

Οι λέξεις εντοπίζονται στο κείμενο ψεκασμού (σελ.205-206): «save», «equipped with», «forcibly», «directly», «speeds through», «readily», «continuously», «feed», «limits», «lines».

Σύνοψη: (ενδεικτική) 1. save. 2. equipped with. 3. forcibly. 4. directly. 5. speeds through. 6. readily. 7. continuously. 8. feed. 9. limits. 10. lines.

Κριτήρια αξιολόγησης:

Λέξεις-κλειδιά: turbocharger (Exercise 5)

Ερώτηση: Find the words in the text which mean: 1. the process of making the air dirty and dangerous with poisonous chemicals: 2. metal end of a hose or device through which a stream of liquid or air flows: 3. water vapour in the air; light fog: 4. stopping at intervals; stopping and starting again: 5. an electronic device which consists of a pre-programmed computer and controls the function of a system: 6. to check regularly:

Απάντηση:

Οι λέξεις εντοπίζονται στα κείμενα ψεκασμού/turbocharger (σελ.205-207): «air pollution», «nozzle», «mist», «intermittent», «control unit», «monitor».

Σύνοψη: (ενδεικτική) 1. air pollution. 2. nozzle. 3. mist. 4. intermittent. 5. (electronic) control unit. 6. monitor.

Κριτήρια αξιολόγησης:

Συνώνυμα λεξιλογίου ψεκασμού/turbocharger (Exercise 6)

Ερώτηση: Make pairs of synonyms out of the two lists below. A: attempt, provide, save, quantity, inject, atomize, govern, monitor, reduce, required. B: economize, effort, needed, control, check, spray, supply, minimize, vaporize, amount.

Απάντηση:

Κάθε λέξη της στήλης Α ταιριάζει με το συνώνυμό της στη στήλη Β βάσει σημασίας.

Σύνοψη: (ενδεικτική) attempt = effort. provide = supply. save = economize. quantity = amount. inject = spray. atomize = vaporize. govern = control. monitor = check. reduce = minimize. required = needed.

Κριτήρια αξιολόγησης:

Ερωτήσεις κατανόησης για τον πετρελαιοκινητήρα (Exercise 1)

Ερώτηση: Answer the questions. 1. What is the main difference between diesel-oil and gasoline engines? 2. Do fuel and air enter the engine at the same time in a diesel engine? 3. Why do diesel-oil engines have neither a carburettor nor a fuel ignition system? 4. What are the advantages of gasoline engines over the diesel-oil ones? 5. Why are diesel-oil engines characterised as energy saving?

Απάντηση:

Οι απαντήσεις δίνονται ρητά στο κείμενο περιγραφής του diesel engine (σελ.209-210).

Σύνοψη: (ενδεικτική) 1. They use a different type of fuel and admit fuel/air differently: gasoline engines admit a mixture of fuel and air, while diesel engines admit only air, injecting fuel directly at the end of compression. 2. No — only air enters during the induction stroke; fuel is injected separately, near the end of the compression stroke. 3. Because the fuel is self-ignited by the heat of the highly compressed air — no spark (hence no distributor/spark plugs) and no premixing in a carburettor is needed. 4. Lower initial cost, quieter operation, faster acceleration, higher maximum speed. 5. Because their very high compression ratio results in greater efficiency and lower fuel consumption.

Κριτήρια αξιολόγησης:

Λεξιλόγιο σύγκρισης βενζινοκινητήρα/πετρελαιοκινητήρα (Exercise 2)

Ερώτηση: Match the following with words or phrases in the text. 1. main/basic: 2. allows to enter/lets in: 3. the temperature at which a fuel ignites automatically/by itself: 4. mixes together: 5. higher production costs: 6. it needs less fuel to operate; it is energy (fuel) saving: 7. more and more people prefer them: 8. cars used only by their owners, not by the public, like buses, trucks and taxis are:

Απάντηση:

Οι φράσεις εντοπίζονται στο κείμενο σύγκρισης diesel/gasoline (σελ.209-210): «essential difference», «admits», «self-ignition point», «intermixes», «higher initial cost», «energy saving...lower fuel consumption», «have become popular», «private cars».

Σύνοψη: (ενδεικτική) 1. essential. 2. admits. 3. self-ignition point. 4. intermixes. 5. higher initial cost. 6. energy (fuel) saving / lower fuel consumption. 7. have become popular. 8. private cars.

Κριτήρια αξιολόγησης:

Πίνακας εξαρτημάτων: βενζινοκινητήρας/πετρελαιοκινητήρας (Exercise 3)

Ερώτηση: Which type of I.C.E. do the following items belong to? Tick appropriately as in the example (Cylinders: all three ✓). PARTS: Pistons, Connecting rods, Crankshaft, Camshaft, Flywheel, Oil sump, Valves, Spark plugs, Injectors, Carburettor, Distributor, Ignition coil, Contact breaker, Fuel tank, Fuel pump, Fuel filter, Electronic control unit. FUEL: Gasoline/petrol, Diesel(-oil).

Απάντηση:

Η ταξινόμηση βασίζεται στα κείμενα των δύο κινητήρων (σελ.176-210): τα βασικά μηχανικά μέρη (πιστόνι, διωστήρας, στροφαλοφόρος, εκκεντροφόρος, σφόνδυλος, λεκάνη λαδιού, βαλβίδες, δεξαμενή/αντλία/φίλτρο καυσίμου) είναι κοινά και στους τρεις τύπους· το σύστημα ανάφλεξης (μπουζί, διανομέας, πηνίο, πλατίνες) υπάρχει ΜΟΝΟ στη συμβατική βενζινομηχανή (και συνήθως και στη βενζινομηχανή με ψεκασμό)· ο εγχυτήρας υπάρχει σε βενζινομηχανή-με-ψεκασμό ΚΑΙ σε πετρελαιοκινητήρα· το καρμπυρατέρ ΜΟΝΟ στη συμβατική βενζινομηχανή· η ηλεκτρονική μονάδα ελέγχου μόνο στη βενζινομηχανή-με-ψεκασμό (και σε σύγχρονο diesel με ψεκασμό, εκτός ύλης εδώ).

Σύνοψη: (ενδεικτική) Κοινά και στους τρεις τύπους: cylinders, pistons, connecting rods, crankshaft, camshaft, flywheel, oil sump, valves, fuel tank, fuel pump, fuel filter. Μόνο συμβατική βενζινομηχανή: spark plugs, carburettor, distributor, ignition coil, contact breaker. Βενζινομηχανή με ψεκασμό ΚΑΙ diesel: injectors (και spark plugs/distributor/ignition coil/contact breaker παραμένουν στη βενζινομηχανή με ψεκασμό, ΟΧΙ στο diesel). Ηλεκτρονική μονάδα ελέγχου: βενζινομηχανή με ψεκασμό. Καύσιμο: gasoline/petrol — και οι δύο τύποι βενζινομηχανής· diesel(-oil) — μόνο ο πετρελαιοκινητήρας.

Κριτήρια αξιολόγησης:

Ο πετρελαιοκινητήρας ΔΕΝ έχει καρμπυρατέρ, διανομέα, πηνίο ανάφλεξης, πλατίνες ή μπουζί (ρητά δηλωμένο στο κείμενο, σελ.210) — έχει όμως εγχυτήρες (injection nozzle/pump, σελ.209).

Πίνακας ομοιοτήτων/διαφορών των τριών τύπων κινητήρα (Exercise 5)

Ερώτηση: Complete the following table with the similarities and differences of the three engine types (parts, fuel and operation, not properties). Similarities row example: cylinders. Differences columns: Gasoline engine (Conventional / With fuel injection) — Diesel-oil engine. Example given: spark plugs / spark plugs (gasoline conventional and injection) vs (none, for diesel).

Απάντηση:

Ο πίνακας συνθέτει πληροφορίες ήδη δοσμένες στα κείμενα των δύο κινητήρων (σελ.176-210): κοινά μέρη, διαφορετικό καύσιμο, διαφορετικό σημείο ανάμειξης μείγματος, διαφορετικός τρόπος ανάφλεξης.

Σύνοψη: (ενδεικτική) Ομοιότητες (και στους τρεις τύπους): κύλινδροι, έμβολα, διωστήρες, στροφαλοφόρος, εκκεντροφόρος, σφόνδυλος, λεκάνη λαδιού, βαλβίδες, δεξαμενή/αντλία/φίλτρο καυσίμου. Διαφορές — Καύσιμο: gasoline (και οι δύο βενζινοκινητήρες) vs diesel-oil. Ανάμειξη μείγματος: στο καρμπυρατέρ (συμβατική βενζινομηχανή) / στο σωλήνα εισαγωγής μέσω εγχυτήρα (βενζινομηχανή με ψεκασμό) / απευθείας στον κύλινδρο (diesel). Ανάφλεξη: με σπινθήρα μπουζί (και οι δύο βενζινοκινητήρες) vs αυτανάφλεξη (diesel). Ειδικά εξαρτήματα: carburettor/distributor/spark plugs/ignition coil/contact breaker μόνο στη συμβατική βενζινομηχανή· injectors στη βενζινομηχανή-με-ψεκασμό ΚΑΙ στο diesel.

Κριτήρια αξιολόγησης:

Συγκριτικές προτάσεις με δοσμένα ζεύγη (Exercise 7 — Comparing)

Ερώτηση: Use expressions from either the above table or the previous exercise (6), to make sentences out of the cues below. 1. Turbine steam engines ↔ gasoline engines (E.C.E. - I.C.E.) 2. Engine without ↔ with a turbocharger (efficient) 3. E.C.E. ↔ I.C.E. (used in automobiles) 4. Gasoline ↔ diesel-oil engine (mechanical parts) 5. In turbine steam engine ↔ reciprocating steam engine (type of motion heat is converted: rotary-reciprocating) 6. Operation of conventional ↔ CNC machine tools (complex) 7. Bolts and rivets ↔ brazing and welding (join metal pieces temporarily ↔ permanently) 8. Gasoline ↔ diesel engines (lubrication system) 9. Conventional ↔ CNC machine tools (controlled by a computer) 10. Wankel ↔ Otto engines (I.C.E.) 11. The fuel/air mixture the engine needs under steady load conditions ↔ for a cold starting (rich) 12. Conventional gasoline engines ↔ engines equipped with fuel injection (save fuel and reduce air pollution).

Απάντηση:

Κάθε ζεύγος cues μετασχηματίζεται σε πρόταση σύγκρισης χρησιμοποιώντας εκφράσεις ομοιότητας/διαφοράς (like/unlike, similar to, different from, the same as, instead of), όπως στο δοσμένο παράδειγμα «Turbine steam engines belong to the E.C.E. Gasoline engines, on the other hand, belong to the I.C.E.».

Σύνοψη: (ενδεικτική) 1. Turbine steam engines belong to the E.C.E.; gasoline engines, on the other hand, belong to the I.C.E. 2. Unlike an engine without a turbocharger, an engine with one is more efficient. 3. E.C.E. and I.C.E. are both used in automobiles / I.C.E. are used in automobiles, unlike most E.C.E. today. 4. The mechanical parts of gasoline and diesel-oil engines are almost the same/similar. 5. In a turbine steam engine, heat is converted into rotary motion; in a reciprocating steam engine, on the other hand, it is converted into reciprocating motion. 6. The operation of CNC machine tools is not so complex as that of conventional ones / unlike CNC machine tools, conventional ones are simpler. 7. Unlike bolts and rivets, which join metal pieces temporarily, brazing and welding join them permanently. 8. The lubrication system of a gasoline engine is similar to that of a diesel engine. 9. Unlike conventional machine tools, CNC ones are controlled by a computer. 10. Wankel and Otto engines are both I.C.E. 11. The fuel/air mixture the engine needs under steady load conditions is not so rich as the one needed for a cold starting. 12. Unlike conventional gasoline engines, engines equipped with fuel injection save fuel and reduce air pollution.

Κριτήρια αξιολόγησης:

Ενδεικτικές προτάσεις — αποδεκτές εναλλακτικές διατυπώσεις με ισοδύναμες εκφράσεις σύγκρισης (like/unlike, similar to/different from, the same as/instead of).

Ταξινόμηση με έτοιμα ζεύγη (Classifying)

Ερώτηση: Use expressions from the appropriate table in the «Language Functions» section in the APPENDIX of your book, to make sentences out of the cues below. 1. Mechanical drills → machine tools 2. Tools → hand tools and machine tools 3. Metals → ferrous and non-ferrous 4. Copper → non-ferrous metals 5. Wrenches → tools commonly used by machinists 6. External combustion engines → turbine steam engines and reciprocating steam engines 7. Diesel engines → reciprocating ICE 8. Heat engines → E.C.E and I.C.E. 9. 2-stroke engines → gasoline reciprocating I.C.E. 10. Wankel and Otto engines → internal combustion engines 11. Fastening devices → bolts, rivets and screws 12. Oxygen → gas 13. Ignition coil → pulse transformer 14. Wood, coal, lignite, turf, oil → fossil fuels.

Απάντηση:

Κάθε cue μετασχηματίζεται σε πρόταση ταξινόμησης με τυπικές εκφράσεις («X is classified as/belongs to/is a type of Y», «X are classified into Y and Z»), χρησιμοποιώντας γνώσεις ήδη εισαγμένες σε προηγούμενα κεφάλαια/ενότητες του βιβλίου.

Σύνοψη: (ενδεικτική) 1. Mechanical drills are classified as/belong to machine tools. 2. Tools are classified into hand tools and machine tools. 3. Metals are classified into ferrous and non-ferrous. 4. Copper is a type of/belongs to non-ferrous metals. 5. Wrenches are tools commonly used by machinists. 6. External combustion engines are classified into turbine steam engines and reciprocating steam engines. 7. Diesel engines are a type of reciprocating ICE. 8. Heat engines are classified into E.C.E. and I.C.E. 9. 2-stroke engines are a type of gasoline reciprocating I.C.E. 10. Wankel and Otto engines are classified as internal combustion engines. 11. Bolts, rivets and screws are classified as fastening devices. 12. Oxygen is a type of gas. 13. The ignition coil is a type of pulse transformer. 14. Wood, coal, lignite, turf and oil are classified as fossil fuels.

Κριτήρια αξιολόγησης:

Αναγνώριση μέρους κινητήρα από περιγραφή (General Exercises, Ex.1)

Ερώτηση: Identify the part of the engine described. 1. It is made from aluminium alloy. It slides inside the cylinder driven either by the combustion of the fuel/air mixture or by the crankshaft. 2. It is driven by the crankshaft. It drives the distributor and opens or closes the valves at the appropriate time. 3. It is made of cast iron. The tubes where the pistons reciprocate are cut in it. 4. It links the piston with the crankshaft converting the reciprocating motion of the one to the rotary movement of the other. 5. There are two, three or four in each cylinder. When opened, they let either the fuel/air mixture in, or the exhaust gases out of the cylinder. 6. It transfers the motion of the pistons to the flywheel. 7. It contains the oil needed to lubricate and cool the engine. 8. It is an electric motor used to start the engine. 9. It produces the sparks which ignite the fuel/air mixture. 10. It is the part of the fuel system that sprays fuel to the cylinders. 11. Driven by the starter motor, it turns the crankshaft in order to move the pistons and start the engine. It also transfers the rotary motion of the crankshaft outside the engine, to the wheels. 12. It is driven by the camshaft. It distributes H.T. current to the spark plugs and ensures that the sparks are created exactly when they are needed. 13. Operating on the venturi effect, it mixes the fuel with air in the correct proportions for every running condition of the engine. Cars with fuel injection don't have one.

Απάντηση:

Κάθε περιγραφή ανασυνθέτει, με νέα διατύπωση, ήδη γνωστά χαρακτηριστικά κάθε εξαρτήματος από όλη την ενότητα (upper/lower engine σελ.176-183, ignition system σελ.192-197, fuel system σελ.198-208).

Σύνοψη: (ενδεικτική) 1. piston. 2. camshaft. 3. cylinder block. 4. connecting rod. 5. valves. 6. crankshaft. 7. oil sump. 8. starter motor. 9. spark plugs. 10. injector. 11. flywheel. 12. distributor (rotor arm). 13. carburettor.

Κριτήρια αξιολόγησης:

Λειτουργία εξαρτημάτων: «η λειτουργία του X είναι να...» (General Exercises, Ex.2A)

Ερώτηση: Complete the sentences in the tables below. A. The function of a(n)/the ignition system, control unit, fuel pump, injector, contact breaker, piston rings, exhaust manifold, fuel regulator is to...

Απάντηση:

Κάθε λειτουργία προκύπτει από τους ήδη δοσμένους ορισμούς σε όλη την ενότητα.

Σύνοψη: (ενδεικτική) The function of the ignition system is to produce the high-voltage sparks which ignite the fuel/air mixture. ...of the control unit is to control the duration/amount of fuel injected, using information from the sensors. ...of the fuel pump is to send/pump gasoline from the tank to the carburettor/injectors. ...of an injector is to spray fuel directly into the manifold/port/cylinder. ...of the contact breaker is to interrupt the circuit and produce pulses of high-voltage current. ...of piston rings is to fill the gap between the piston and the cylinder wall, preventing loss of power. ...of the exhaust manifold is to collect and lead the burnt gases out of the cylinders. ...of the fuel regulator is to limit/regulate the pressure in the fuel lines.

Κριτήρια αξιολόγησης:

Σύνθεση εξαρτημάτων: «το X αποτελείται από...» (General Exercises, Ex.2B)

Ερώτηση: Complete the sentences in the tables below. B. The upper engine / fuel system of the diesel engine / ignition system of a conventional gasoline engine / lower engine / fuel system of a conventional petrol engine / carburettor consists of...

Απάντηση:

Κάθε απάντηση συνθέτει τα εξαρτήματα κάθε συστήματος όπως ήδη περιγράφηκαν στην ενότητα.

Σύνοψη: (ενδεικτική) The upper engine consists of the cylinder head and the cylinder block (with the valves, spark plugs, pistons and piston rings). The fuel system of the diesel engine consists of the fuel tank, fuel filter, injection pump and injectors (no carburettor). The ignition system of a conventional gasoline engine consists of the ignition coil, the distributor (with the contact breaker and rotor arm) and the spark plugs. The lower engine consists of the crankshaft, connecting rods, flywheel and oil sump. The fuel system of a conventional petrol engine consists of the fuel tank, fuel pump, fuel filter and carburettor. The carburettor consists of the float chamber, the venturi and the throttle (butterfly valve).

Κριτήρια αξιολόγησης:

Σύνθετα ουσιαστικά (General Exercises, Ex.3)

Ερώτηση: Form compound nouns by matching the two columns. Group A: spark, piston, inlet, connecting, cylinder, combustion, injection, fuel / valve, nozzle, injection, plug, ring, block, chamber, rod. Group B: oil, fuel, exhaust, ignition, rotor, contact, gudgeon, pressure / manifold, breaker, sump, arm, pump, regulator, coil, pin.

Απάντηση:

Κάθε ζεύγος λέξεων σχηματίζει έναν τεχνικό όρο ήδη εισαγμένο στην ενότητα.

Σύνοψη: (ενδεικτική) Group A: spark plug, piston ring, inlet valve, connecting rod, cylinder block, combustion chamber, injection nozzle, fuel injection. Group B: oil sump, fuel pump, exhaust manifold, ignition coil, rotor arm, contact breaker, gudgeon pin, pressure regulator.

Κριτήρια αξιολόγησης:

Ερωτήσεις Wh- (General Exercises, Ex.4)

Ερώτηση: Ask questions to which the following sentences are the answers. Begin your questions with the words in parentheses. 1. In the internal combustion engines, combustion takes place inside the engine. (Where) 2. The main parts of the upper engine are the cylinder head and the cylinder block. (Which) 3. The pistons move up and down inside the cylinder. (How/Where) 4. As the piston rises, it compresses the fuel/air mixture in the combustion chamber. (When/What) 5. The piston moves up to expel burnt gases. (Why) 6. Soon after the induction stroke, the inlet valve closes. (When) 7. At about the end of the compression stroke, a fine spray of fuel is injected into the cylinder. (When/What/Where) 8. The rotor arm distributes the H.T. current to the spark plugs. (Which part of the distributor/Where) 9. In gasoline engines, the fuel is ignited by means of a spark. (How) 10. Contact breaker points open and close about 10 million times every 1,000 miles. (How many times) 11. As the HT current jumps the air gap from the centre to the side electrode, a spark is created. (How/When) 12. In modern cars, the timing of the spark is controlled by the microprocessor which monitors all the functions of the engine. (How)

Απάντηση:

Κάθε ερώτηση σχηματίζεται αντιστρέφοντας τη δοσμένη πρόταση-απάντηση σε ερώτηση Wh- με το δοσμένο ερωτηματικό μόριο.

Σύνοψη: (ενδεικτική) 1. Where does combustion take place in internal combustion engines? 2. Which are the main parts of the upper engine? 3. How/Where do the pistons move? 4. When/What does the piston compress as it rises? 5. Why does the piston move up? 6. When does the inlet valve close? 7. When/What/Where is a fine spray of fuel injected? 8. Which part of the distributor distributes the H.T. current to the spark plugs? / Where does the rotor arm distribute the H.T. current? 9. How is the fuel ignited in gasoline engines? 10. How many times do contact breaker points open and close every 1,000 miles? 11. How/When is a spark created? 12. How is the timing of the spark controlled in modern cars?

Κριτήρια αξιολόγησης:

Ενεργητική-Παθητική φωνή (General Exercises, Ex.5)

Ερώτηση: A. Underline the correct verb form (active or passive). 1. The piston rings fill / are filled the gap between the piston and the cylinder wall. 2. The amount and duration of injection control / is controlled by a computer. 3. The pressure of combustion forces / is forced the piston down the cylinder. 4. The fuel/air mixture compresses / is compressed in the combustion chamber by the rising piston. 5. The rotor arm in the distributor drives / is driven by the camshaft. 6. Unlike gasoline engines, it is the high temperature of the compressed air that ignites / is ignited the fuel in the cylinder of a diesel engine, not a spark. B. Decide which voice the following sentences are in, and form the verbs in parentheses appropriately. 1. The fuel regulator (regulate) the pressure in the fuel lines. 2. The burnt gases (expell) from the cylinder by the rising piston. 3. The connecting rod (convert) the reciprocating motion of the piston into the rotary motion of the crankshaft. 4. The expansion of burning gases (drive) the piston down. 5. In a steam power plant, heat energy (convert) into mechanical energy by a turbine steam engine. 6. In gasoline engines, the fuel/air mixture (ignite) by a spark. 7. The flywheel (transmit) the rotary motion of the crankshaft to the wheels. 8. The picture (show) a simple power plant. 9. When the compressed air has reached the self-ignition point of diesel, a fine spray of fuel (inject) in the cylinder by the injection nozzle. 10. In modern cars, the functions of the engine (monitor) by a computer.

Απάντηση:

Η επιλογή ενεργητικής/παθητικής βασίζεται στο αν το υποκείμενο ΕΝΕΡΓΕΙ (active) ή ΔΕΧΕΤΑΙ την ενέργεια (passive), σύμφωνα με τα ήδη γνωστά γεγονότα λειτουργίας του κινητήρα.

Σύνοψη: (ενδεικτική) A. 1. fill (active — τα δαχτυλίδια είναι το υποκείμενο που γεμίζει το κενό). 2. is controlled (passive). 3. forces (active). 4. is compressed (passive). 5. is driven (passive). 6. ignites (active). B. 1. regulates (active). 2. are expelled (passive). 3. converts (active). 4. drives (active). 5. is converted (passive). 6. is ignited (passive). 7. transmits (active). 8. shows (active). 9. is injected (passive). 10. are monitored (passive).

Κριτήρια αξιολόγησης:

«Are you a good mechanic;» — 40 ερωτήσεις Σωστό/Λάθος (General Exercises, ανακεφαλαίωση)

Ερώτηση: Check your knowledge about car engines. Are the following statements true (T) or false (F)? I.C.E.: 1. The cylinder head is a part of the lower engine. 2. Most engines have the cylinders cut in the cylinder block. 3. According to the arrangement of cylinders, I.C.E. are distinguished into in-line, radial, horizontally opposed and vee engines. 4. The connecting rod moves inside the cylinder. 5. The piston rings fill the gap between the crankshaft and the cylinder wall. 6. The connecting rod is linked to the flywheel by means of the gudgeon pin. 7. The pistons' reciprocating motion is changed into rotary by means of the valve springs. 8. The valves are opened or closed by the camshaft. 9. The valves open and close ports in the cylinders. 10. The crankshaft is driven by the camshaft. 11. The flywheel is connected to the gear box through the ignition coil. The 4-stroke cycle of operation in the petrol engine: 12. During the induction stroke, the exhaust valve is open and the inlet closed. 13. The mixture of air and fuel enters the cylinder on the compression stroke. 14. Ignition occurs on the power stroke. 15. The fuel and air mixture is ignited by means of a spark. 16. During the compression and power strokes, both valves are open. 17. The piston moves down during the intake and power strokes. 18. As the piston moves down, it sucks fuel and air in the cylinder, and as it moves up, it expels burnt gases out of it. The ignition and fuel system in petrol engines: 19. The ignition coil converts the HT current produced by the battery to a 12V low-tension current. 20. The ignition coil is a step-up pulse transformer. 21. The contact breaker is an on/off switch which produces pulses of current. 22. The rotor arm, driven by the camshaft, distributes the current to the spark plugs. 23. In cars with electronic ignition, the distributor has a transistor instead of a contact breaker. 24. Gasoline engines use diesel-oil as fuel. 25. The operation of the carburettor is based on the venturi effect. 26. A jet is a tube through which the air enters the carburettor barrel. 27. Engines equipped with fuel injection have carburettors but no distributors. 28. The fuel injection is controlled by various sensors. 29. The control unit in an electronic ignition system is a computer. 30. In conventional petrol engines, fuel and air are mixed in the cylinder. 31. Fuel injection reduces the car's efficiency. Diesel-oil engines: 32. The diesel engine admits a mixture of fuel and air during the induction strokes. 33. In a diesel engine, the temperature of the compressed air is below the self-ignition point of the fuel. 34. In a diesel engine, the fuel is sprayed in the cylinder at the end of the induction stroke. 35. In a diesel engine, the fuel is self-ignited. 36. Diesel engines have carburettors and distributors, but no spark plugs. 37. The operation of a diesel engine is less noisy than that of a gasoline engine. 38. Gasoline engines have higher maximum speed than diesel engines. 39. Diesel engines have a higher compression ratio and consume less fuel than petrol engines. 40. A gasoline engine has a slower acceleration than a diesel one.

Απάντηση:

Κάθε μία από τις 40 προτάσεις ελέγχεται ως Σωστή/Λανθασμένη διασταυρώνοντας με τα γεγονότα που έχουν ήδη παρουσιαστεί σε όλη την ενότητα Heat Engines (upper/lower engine σελ.176-183, κύκλος 4 χρόνων σελ.187-191, σύστημα ανάφλεξης σελ.192-197, καρμπυρατέρ/ψεκασμός σελ.198-208, πετρελαιοκινητήρας σελ.209-214). Ενδεικτικές διορθώσεις: το cylinder head ανήκει στο ΠΑΝΩ (όχι κάτω) μέρος του κινητήρα· τα δαχτυλίδια εμβόλου γεμίζουν το κενό εμβόλου-κυλίνδρου (όχι στροφαλοφόρου)· ο διωστήρας συνδέεται με τον στροφαλοφόρο μέσω gudgeon pin, ΟΧΙ με τον σφόνδυλο· η παλινδρομική κίνηση γίνεται περιστροφική μέσω στροφαλοφόρου/διωστήρα, ΟΧΙ ελατηρίων βαλβίδων· ο εκκεντροφόρος κινείται ΑΠΟ τον στροφαλοφόρο (όχι αντίστροφα)· ο σφόνδυλος συνδέεται με το κιβώτιο ταχυτήτων μέσω του ΣΥΜΠΛΕΚΤΗ, όχι του πηνίου ανάφλεξης· στην εισαγωγή η βαλβίδα εισαγωγής είναι ανοιχτή (όχι η εξαγωγής)· το μείγμα μπαίνει στην ΕΙΣΑΓΩΓΗ (όχι συμπίεση)· και στους δύο χρόνους συμπίεσης/ισχύος ΚΑΙ ΟΙ ΔΥΟ βαλβίδες είναι ΚΛΕΙΣΤΕΣ (όχι ανοιχτές)· το πηνίο μετατρέπει χαμηλή ΣΕ υψηλή τάση (όχι αντίστροφα)· ο ρότορας κινείται από τον ΕΚΚΕΝΤΡΟΦΟΡΟ (όχι στροφαλοφόρο)· βενζινοκινητήρες χρησιμοποιούν βενζίνη (όχι πετρέλαιο)· ο jet είναι για ΚΑΥΣΙΜΟ (όχι αέρα)· οι κινητήρες ψεκασμού ΔΕΝ έχουν καρμπυρατέρ· σε συμβατικό βενζινοκινητήρα το μείγμα φτιάχνεται στο ΚΑΡΜΠΥΡΑΤΕΡ (όχι στον κύλινδρο)· ο ψεκασμός ΑΥΞΑΝΕΙ (δεν μειώνει) την απόδοση· ο πετρελαιοκινητήρας εισάγει ΜΟΝΟ αέρα στην εισαγωγή· η θερμοκρασία συμπιεσμένου αέρα είναι ΠΑΝΩ (όχι κάτω) από το σημείο αυτανάφλεξης· το καύσιμο ψεκάζεται στο τέλος της ΣΥΜΠΙΕΣΗΣ (όχι εισαγωγής)· το diesel ΔΕΝ έχει κανένα από καρμπυρατέρ/διανομέα/μπουζί· το diesel είναι πιο ΘΟΡΥΒΩΔΕΣ (όχι λιγότερο) από τη βενζινομηχανή· η βενζινομηχανή έχει ΜΕΓΑΛΥΤΕΡΗ μέγιστη ταχύτητα, το diesel πιο ΑΡΓΗ επιτάχυνση.

Σύνοψη: (ενδεικτική) 1.F 2.T 3.T 4.F 5.F 6.F 7.F 8.T 9.T 10.F 11.F 12.F 13.F 14.T 15.T 16.F 17.T 18.F 19.F 20.T 21.T 22.T 23.T 24.F 25.T 26.F 27.F 28.T 29.T 30.F 31.F 32.F 33.F 34.F 35.T 36.F 37.F 38.T 39.T 40.F. Διορθώσεις για τα Λανθασμένα: 1 — cylinder head = upper engine. 4 — the PISTON moves inside the cylinder (not the connecting rod). 5 — piston rings fill the gap between the PISTON and the cylinder wall. 6 — the PISTON is linked to the connecting rod by the gudgeon pin; the connecting rod is linked to the CRANKSHAFT. 7 — reciprocating→rotary conversion is by the CRANKSHAFT/connecting rod, not the valve springs. 10 — the CAMSHAFT is driven by the crankshaft (not vice versa). 11 — flywheel connects to the gear box through the CLUTCH. 12 — during induction, INLET open/exhaust closed. 13 — mixture enters on the INDUCTION stroke. 16 — during compression/power BOTH valves are CLOSED. 18 — this is an oversimplification: the piston also moves down on the power stroke (driven by combustion, not sucking) and up on the compression stroke (compressing, not expelling). 19 — the coil converts LOW-tension DC (12V) TO high-tension AC. 22 — rotor arm is driven by the CAMSHAFT. 24 — gasoline engines use GASOLINE/PETROL. 26 — a jet is a tube through which FUEL enters. 27 — fuel-injection engines have NO carburettor (they may still have a distributor). 30 — in conventional engines, fuel/air are mixed in the CARBURETTOR. 31 — fuel injection INCREASES efficiency. 32 — diesel admits ONLY AIR on induction. 33 — compressed-air temperature is ABOVE the self-ignition point. 34 — fuel is sprayed at the end of the COMPRESSION stroke. 36 — diesel has NEITHER carburettor NOR distributor NOR spark plugs. 37 — diesel is NOISIER than gasoline. 40 — gasoline has FASTER acceleration than diesel (diesel is slower).

Κριτήρια αξιολόγησης:

Ερώτηση 14 (ignition on the power stroke) και ερώτηση 9 (valves open/close ports) ερμηνεύονται σύμφωνα με την ακριβή διατύπωση του κύκλου 4 χρόνων του βιβλίου (σελ.188), όπου η ανάφλεξη περιγράφεται μέσα στην παράγραφο του «power stroke».

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