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Pic. 31: 1. Insulator. 2. Ignition coil housing. 3. Insulating paper windings. 4. Primary winding. 5. Secondary winding. 6. Insulating tube of the primary winding. 7. Output terminal of the end of the primary winding. 8. Contact screw. 9. High voltage terminal. 10. Cover. 11. Terminal "+B" output of the beginning of the primary and the end of the secondary windings. 12. Spring of the central terminal. 13. Frame of the secondary winding. 14. External insulation of the primary winding. 15. Mounting bracket. 16. External magnetic core. 17. Core. 18. Contact nut. 19. Spark plug insulator. 20. Rod. 21. Candle body. 22. O-ring. 23. Heat sink washer. 24. Central electrode. 25. Spark plug side electrode. 26. Ignition distributor roller. 27. Roller oil slinger. 28. Washer. 29. Power supply wire to the distributor. 30. Cover spring. 31. Vacuum regulator housing. 32. Diaphragm. 33. Vacuum regulator cover. 34. Nut. 35. Vacuum regulator spring. 36. Thrust vacuum regulator. 37. Grease wick (felt) cam. 38. Base plate of the ignition timing regulator. 39. Ignition distributor rotor. 40. Ground electrode with terminal for wire to spark plug. 41. Ignition distributor cover. 42. Central terminal for the wire from the ignition coil. 43. Central carbon electrode with a spring. 44. Central contact of the rotor. 45. Resistor 5-6 kOhm for suppression of radio interference. 46. External contact of the rotor. 47. spring of the centrifugal ignition timing controller. 48. The leading plate of the centrifugal regulator. 49. Weight of the ignition timing regulator. 50. Insulating sleeve. 51. Breaker cam. 52. Lever insulating block. 53. Breaker lever. 54. Rack with breaker contacts. 55. Breaker contacts. 56. Movable breaker plate. 57. Capacitor 0.20-0.25 uF. 58. Ignition distributor housing. 59. Bearing of the movable breaker plate. 60. Oiler housing. 61. Terminal screw. 62. Bearing lock plate. 63. Ignition distributor. 64. Spark plugs. 65. Ignition coil. 66. Battery. 67. Generator. 68. Mounting block. 69. Ignition switch. I - Characteristics of the centrifugal regulator of the ignition distributor. A - ignition timing deg; n - frequency of rotation of the ignition distributor shaft, min-1. II - Characteristics of the vacuum regulator of the ignition distributor. A - ignition timing, deg; R - rarefaction GPa (mm. rt. Art.). III - Scheme of operation of the centrifugal ignition timing controller. A - ignition timing, deg. IV - Scheme of the ignition system.
The elements of the ignition system include the spark coil and spark plugs, the ignition switch, the ignition distributor, and the high and low voltage wires.
Ignition coil. On VAZ-2105 and VAZ-2104 vehicles, an ignition coil of type B-117A is installed. It is located in the engine compartment and is mounted on two bolts welded to the left mudguard. The ignition coil is used to convert low voltage intermittent current (12 V) into high voltage current (11-20 kV). The coil is a transformer "iron" the core 17 and the annular outer magnetic circuit 14. The core is in a cardboard frame, on which the secondary winding 5 is wound first, and the primary winding 4 is wound on top of it. The windings, together with the magnetic circuit and the core, are placed in an aluminum case and filled with transformer oil. The windings, together with the core, are mounted on a bowl-shaped ceramic insulator 1. From above, the coil body is closed with a plastic cover 10, the shoulder of which is rolled into the body and sealed with an oil-resistant rubber gasket. The terminals of the windings are connected to the terminals filled in the cover. To terminal 11 marked "+B", the conclusions of the beginning of the primary and the end of the secondary winding are soldered, and to terminal 7 (unmarked) the terminal of the end of the primary winding is soldered. Output of the beginning of the secondary winding (high voltage output) connected to the core plates and, further, through the spring 12 and screw 8 - with terminal 9.
Spark plugs are designed to ignite the combustible mixture in the engine cylinders by a spark discharge between the electrodes. On VAZ-2105 and VAZ-2104 cars, A17J1B spark plugs or similar foreign-made spark plugs are used. The letter A in the designation of the candle indicates that the thread of the screw part is M14x1.25. Numbers (17) characterize the glow number of the candle. Second letter (3) means that the length of the threaded part of the spark plug body is 19 mm. The last letter B means that the thermal cone (skirt) the insulator protrudes beyond the end of the housing. The gap between the electrodes of the spark plugs should be 0.5-0.6 mm.
The design of the candles is non-separable. A ceramic insulator 19 is rolled in a steel case 21. A composite central electrode is located in the insulator hole, consisting of the electrode 24 itself, made of a heat-resistant chromium-nickel alloy, and a steel rod 20. This rod is filled in the insulator with a conductive glass sealant that prevents gas breakthrough through the insulator hole. The gap between the body of the spark plug and the insulator is sealed by rolling the body around the collar of the insulator, and also by a steel washer 23, which also serves to remove heat from the insulator to the body, maintaining the temperature of the insulator skirt at a certain level.
The ignition switch is designed to turn on and off the ignition circuits and other electrical consumers of the car. The ignition switch is mounted on a bracket on the left side of the steering column and secured with two screws.
The switch consists of a housing with a lock and an anti-theft device and a contact part. The principle of operation of the anti-theft device is that after removing the key from the lock, set to position III (Parking), the locking rod of the lock extends, enters the groove of the steering shaft and blocks the shaft. The key can only be removed from the lock in position III.
Until 1985, ignition switches used a contact part with push-to-action contacts. Her fixed contacts were closed by pressing movable conductive jumpers to them. Since 1985 the contact part with sliding contacts has been used. This contact part has brass rack-plugs with contacts in the block.
The ignition distributor serves to interrupt the current in the low voltage circuit of the ignition coil and distribute the high voltage pulses to the spark plugs. On VAZ-2105 and VAZ-2104 vehicles, an ignition distributor of type 30.3706-01 is used. It is installed in the left front of the engine and is driven by a helical gear 27 (see fig. 4), having a slotted hole into which the shank of the distributor shaft is inserted.
The main parts of the ignition distributor are: a chopper, centrifugal and vacuum ignition timing controllers and a distributor.
The interrupter consists of a cam 51 with four protrusions and a stand 54 with contacts that the cam opens during rotation. The cam is lubricated with felt felt 37 impregnated with oil. An axis is riveted to the post, on which a lever 53 is installed on a textolite bushing with a contact pressed by a lamellar spring to the post contact. The gap between the breaker contacts should be 0.4±0.05 mm.
The support plate 38 of the centrifugal ignition timing controller is soldered to the upper end of the cam bushing. Axes of ceramic-metal weights 49 and racks of springs 47 are riveted to the plate. The other end of the spring is attached to racks riveted to the plate 48 of the centrifugal regulator. When the engine is running under the action of centrifugal forces, the weights diverge, rest against the plate 48 and, overcoming the resistance of the springs, turn the plate 38 (and hence the cam 51) clockwise relative to the ignition distributor shaft.
The vacuum ignition timing controller consists of a housing 31 with a cover 33, between which a flexible diaphragm 32 is clamped. On the one hand, a rod 36 is attached to the diaphragm, and on the other there is a spring 35 that presses the diaphragm with a rod in the direction of rotation of the cam 51. Under the action of vacuum, the diaphragm bends and through the rod turns the plate with the contacts of the breaker counterclockwise.
The distributor consists of a rotor 39 and electrodes installed in a plastic cover 41. The central 44 and outer 46 contacts of the rotor are riveted on the rotor, between which a resistor 45 is located in a special recess to suppress radio interference, a spring-loaded carbon electrode 43 is supported in the central contact of the rotor. voltage from the ignition coil to the rotor. When the rotor rotates, these pulses are transmitted from the outer contact 46 to the side electrodes 40, filled in the cover and, further, to the spark plugs.
High voltage wires are used to transmit high voltage current pulses from the ignition coil to the distributor and from the distributor to the spark plugs. To reduce radio and television interference, the wires have a resistance distributed along the length of 200 Ohm / m. The core of the wire, which is a cord of linen yarn, is enclosed in a sheath made of plastic with a maximum addition of ferrite. Over this shell is wound a wire with a diameter of 0.11 mm from an alloy of nickel and iron, 30 turns per centimeter. Outside, the wire has an insulating sheath made of polyvinyl chloride.
Operation of the ignition system. The ignition system has a primary circuit (low voltage) and secondary (high voltage). The current in the primary circuit closes along the path: "plus" battery 66 - pins "30/1", "15" ignition switch 69 clip "+B", ignition coil primary 65 ignition distributor breaker 63 ground "minus" battery. If the alternator voltage is greater than the battery voltage, then the current comes from the clamp "30" generator and closes through the ground to its rectifier. The rest of the current path is the same as described above.
Since 1986, an additional ignition relay type 113.3747-10 has been installed on VAZ-2105 and VAZ-2104 vehicles. In this case, when the ignition is switched on, the contacts "30/1" And "15" the ignition switch close the power supply circuit of the relay winding. The relay is activated and current flows through its closed contacts to the primary winding of the ignition coil. The relay is located under the instrument panel next to the ignition switch.
The current flowing through the primary winding of the ignition coil creates a magnetic force field around the turns, when the breaker contacts are opened, the current in the primary winding disappears, the magnetic force field is sharply reduced and induces an EMF in them. In the secondary winding, the EMF reaches 12-24 kV, and in the primary 200-300 V. The faster the magnetic lines of force cross the turns of the windings (those. the faster the disappearance of the magnetic field), the greater the EMF induced in them.
EMF induced in the primary winding of the ignition coil (EMF self-induction) tends to maintain the vanishing current and therefore slow down the contraction of the magnetic field. In addition, it causes sparking between the open contacts of the breaker. To prevent these phenomena, there is a capacitor 57 in the ignition distributor. If there were no capacitor, then the disappearance of the magnetic force field would occur relatively slowly and the EMF in the secondary winding would not exceed 4000-5000 V.
The high voltage current induced in the secondary winding of the ignition coil is closed along the path: secondary winding of the ignition coil - high voltage wire central terminal of the cover, central contact 44, resistor 45, external contact. 46 rotor, side electrode of the distributor cap spark plug - "weight". Then, in parallel circuits, the current passes through the battery, generator, all connected consumers to the contacts "30/1" And "15" ignition switch, and then on the clamp "+B" to the secondary winding of the ignition coil.
To obtain maximum power and efficiency of the engine, it is necessary to ignite the combustible mixture a little earlier than the arrival of the piston at TDC, so that combustion ends when the crankshaft rotates 10-15°after TDC, i.e. the spark discharge must be created in advance. The initial ignition timing should be 5-7°to the TDC. With too early ignition, the combustible mixture burns out before the piston arrives at the TDC. and slows it down. As a result, engine power is reduced, knocks occur, the engine overheats and runs unsteadily at low idling speed. With late ignition, the combustible mixture will burn out when the piston goes down, i.e. under conditions of increasing volume. In this case, the gas pressure will be lower than during normal ignition and the engine power will decrease.
In order for the combustion of fuel to occur in a timely manner, each engine speed needs its own ignition timing. this work is performed by a centrifugal ignition timing controller. With an increase in the frequency of rotation of the distributor shaft, the weights 49 rotate relative to the axes under the action of centrifugal forces. The edges of the weights rest against the drive plate 48 and, overcoming the tension of the springs, turn the base plate 38 together with the breaker cam 51 by angle A. The cam protrusions open the breaker contacts earlier and the ignition advance increases. With a decrease in the rotational speed of the roller, the centrifugal forces acting on the weights decrease and the springs turn the support plate 38 with the cam 51 against the direction of rotation of the roller, i.e. ignition advance is reduced.
When the load on the engine changes, the content of residual gases in the engine cylinders changes. At heavy loads, when the carburetor throttles are fully open, the content of residual gases in the combustible mixture is low, so the mixture burns faster and ignition must occur later. When the engine load is reduced (throttle cover) the content of residual gases increases, the mixture burns longer and ignition should occur earlier. The ignition timing is adjusted by the vacuum ignition timing controller, depending on the engine load.
The diaphragm of the vacuum regulator of the ignition distributor is affected by a vacuum taken from the area above the throttle valve of the primary chamber of the carburetor. When the throttle is closed (engine idle), the vacuum sampling hole is above the edge of the throttle valve, so there is no vacuum and the vacuum regulator does not work. With small openings of the throttle valve, a vacuum appears, the diaphragm 32 is pulled back and the rod 36 turns the movable plate 56 of the interrupter against the direction of rotation of the ignition distributor shaft. The ignition advance is increased. As the throttle opens further (load increase) the vacuum decreases and the spring presses the diaphragm to its original position. The movable interrupter plate rotates in the direction of rotation of the ignition distributor shaft and the ignition advance decreases.