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Pic. 31. Ignition system.
1. Insulator: 2. Ignition coil housing; 3. Insulating paper windings; 4. Primary winding; 5. Secondary winding; 6. Primary insulating tube; 7. Output terminal of the end of the primary winding; 8. Contact screw; 9. High voltage terminal; 10. Lid; 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 circuit; 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. Current 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. Side electrode with terminal; 41. Ignition distributor cover; 42. Central electrode with terminal; 43, Central electrode carbon; 44. Central contact of the rotor; 45. Resistor 5-6 kOhm for suppression of radio interference; 46. External contact of the rotor; 47. Spring ignition timing regulator; 48. Plate 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 plate of the interrupter; 60. Oiler housing; 61. Terminal screw; 62. Bearing lock plate; 63. Ignition distributor; 64. Spark plugs; 65. Ignition switch; 66. Ignition coil; 67. Generator; 68. Battery; 69. Sensor-distributor ignition; 70. Switch; A. Ignition timing; B. To power supplies; I. Ignition coil; II. Spark plug; III. Distributor; IV. Diagram of a classic ignition system; V. Scheme of operation of the centrifugal ignition timing controller. VI. Diagram of a contactless ignition system.
1. Insulator: 2. Ignition coil housing; 3. Insulating paper windings; 4. Primary winding; 5. Secondary winding; 6. Primary insulating tube; 7. Output terminal of the end of the primary winding; 8. Contact screw; 9. High voltage terminal; 10. Lid; 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 circuit; 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. Current 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. Side electrode with terminal; 41. Ignition distributor cover; 42. Central electrode with terminal; 43, Central electrode carbon; 44. Central contact of the rotor; 45. Resistor 5-6 kOhm for suppression of radio interference; 46. External contact of the rotor; 47. Spring ignition timing regulator; 48. Plate 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 plate of the interrupter; 60. Oiler housing; 61. Terminal screw; 62. Bearing lock plate; 63. Ignition distributor; 64. Spark plugs; 65. Ignition switch; 66. Ignition coil; 67. Generator; 68. Battery; 69. Sensor-distributor ignition; 70. Switch; A. Ignition timing; B. To power supplies; I. Ignition coil; II. Spark plug; III. Distributor; IV. Diagram of a classic ignition system; V. Scheme of operation of the centrifugal ignition timing controller. VI. Diagram of a contactless ignition system.
On cars VAZ-2103, VAZ-2106, the classic ignition system is mainly used (scheme IV). A contactless ignition system can be installed on the VAZ-21065 (scheme VI).
Ignition coil. In the classic ignition system, ignition coils B-117A are used, and in the non-contact one - 27.3705, which differ in winding data and some details. The coil is a transformer with two windings: primary 4 and secondary 5, and is used to convert low voltage current (12 V) into high voltage current (11-20 kV) for breakdown of the air gap between the electrodes of the spark plugs.
Spark plug installed type A-17DV for the classic ignition system and A-17DV-10 for non-contact, or foreign-made candles similar to them. The design of candles is non-separable, traditional. The gap between the electrodes of the spark plugs is 0.5-0.6 mm for A-17DV and 0.7-0.8 mm for A-17DV-10.
ignition switch mounted on the steering shaft bracket, consists of a housing with a lock and an anti-theft device and a contact part. The principle of operation of the 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 it.
Electronic switch used in a non-contact ignition system to interrupt the current in the primary circuit of the ignition coil according to the signals of a non-contact sensor. Interchangeable switches of various brands can be used: 3620.3734, HIM-52, BAT10.2 or PZE4020. The magnitude of the current pulses is 8-9 A. Automatic shutdown of the current through the ignition coil is provided after 2-5 seconds with the engine off, but the ignition on.
Distributor 30.3706 serves to interrupt the current in the low voltage circuit of the ignition coil and distribute high voltage pulses to the spark plugs. The ignition distributor is installed in the left front of the engine and is driven by a helical gear 27 (see fig. 4).
The interrupter consists of a cam 51 with four projections and a rack 54 with contacts that the cam opens during rotation. A support plate 38 of a centrifugal ignition timing controller with weights 49 is soldered to the upper end of the cam bushing. A vacuum regulator is attached to the side of the distributor housing, consisting of a housing 31 with a cover 33, between which a flexible diaphragm 32 is clamped. A rod 36 is attached to the diaphragm, connected to the movable plate 56 breakers.
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 there is an interference suppression resistor 45 in the recess. A spring-loaded carbon electrode 43 rests against the central contact of the rotor.
Ignition distribution sensor 37.3706 is used in a non-contact ignition system. It differs from the ignition distributor 30.3706 only in that instead of the interrupter, a non-contact sensor is installed on the movable plate, and a cylindrical steel screen with four slots is attached to the base plate 38 from below.
The proximity sensor operates on the basis of the Hall effect and consists of a semiconductor plate with an integrated circuit and a permanent magnet. Between them there is a gap through which the steel screen passes. When the screen body is in the gap, the magnetic lines of force close through the screen and do not act on the plate. If there is a screen slot in the gap, then a magnetic field acts on the semiconductor plate and the potential difference is removed from it. A microcircuit built into the sensor converts this potential difference into voltage pulses.
Operation of the ignition system
When the engine is running, the breaker interrupts the current in the primary winding of the ignition coil. At this moment, the magnetic field in the ignition coil is sharply compressed and, crossing the turns of the winding, induces an EMF in it of the order of 12-24 kV. The high voltage current goes to the central terminal of the ignition distributor, then through the rotor contacts to the side electrode and then to the spark plug, creating a spark discharge between its electrodes.
Capacitor 57 serves to dampen the self-induction EMF in the primary winding of the ignition coil and to reduce sparking between the breaker contacts. If there were no capacitor, then the EMF in the secondary winding would not exceed 4000-5000 V.
To obtain maximum engine power, it is necessary to ignite the combustible mixture a little earlier than the piston reaches TDC, so that combustion ends when the crankshaft rotates 10-15°after TDC. Each crankshaft speed requires its own ignition timing. So at 750800 rpm, the initial ignition timing is 3-5°. With an increase in the speed of rotation, the ignition timing must increase, and this task is performed by the centrifugal ignition timing controller.
With an increase in the rotational speed, the weights 49 diverge under the action of centrifugal forces and turn the support plate 38 together with the breaker cam 51 by angle A in the direction of rotation of the roller. The cam protrusions open the breaker contacts earlier and the ignition advance increases.
The vacuum regulator changes the ignition timing depending on the load on the engine. At low loads, the content of residual gases in the combustible mixture is high, the mixture burns more slowly, it must be ignited earlier and vice versa. The diaphragm of the regulator is affected by a vacuum taken from the zone above the throttle valve of the first chamber of the carburetor. At small throttle openings (light load) under the action of vacuum, the diaphragm 32 is pulled back and the rod 36 turns the movable plate 52 of the interrupter against the direction of rotation of the roller. 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 non-contact ignition system works in the same way as the classic one, only instead of a breaker, the current in the primary circuit of the ignition coil is interrupted by the switch based on the signals of the non-contact sensor in the ignition distributor.