Daewoo Nexia

since 1994 of release

Repair and car operation



Deu Neksiya
+ Maintenance instruction
+ Maintenance
+ Engine
+ 3. Engine (two top camshafts)
+ cooling System
+ Toplevnaya and exhaust systems
+ Electric chain
+ 7. Ignition system
+ 8. Electronic control unit and sensors
+ Transmission
+ 10. Five-speed transmission and main RPO MM5 broadcast
+ 11. Automatic Transmission
+ Steering
+ Running gear
+ 14. Forward suspension bracket
+ 15. Drive of forward wheels
+ 16. Back suspension bracket
- Brake system
   17.2. General description
   17.3. Check of a technical condition of brake system
   17.4. Filling of a tank of the main brake cylinder
   17.5. Air removal from brake system
   17.6. Washing of brake system
   17.7. Check of a regulator of brake forces
   17.8. Brake hoses (forward)
   17.9. Brake hoses (back)
   + 17.10. Parking brake
   17.11. Check of a condition of forward brake slips
   17.12. Check of a condition of back brake slips
   17.13. Brake disks
   17.14. Brake drums
   17.15. Brake pedal
   17.16. Main brake cylinder
   17.17. Tank
   17.18. Regulators of brake forces (proportional valves)
   17.19. Main brake cylinder assembled
   17.20. Repair of the main brake cylinder
   17.21. Disk brake mechanism
   17.22. Blocks and slips
   17.23. Protective cover of the piston
   17.24. Brake disk
   17.25. Support
   17.26. Guard
   17.27. Support repair
   17.28. Drum-type brake mechanism
   17.29. Adjustment of the brake mechanism
   17.30. Adjustment of the parking brake
   17.31. Basic brake disk
   17.32. Wheel cylinder
   17.33. Repair of the wheel cylinder
   17.34. Vacuum amplifier of brakes
   - 17.35. Anti-blocking system of brakes
      17.35.1. Functioning of signaling devices
   17.36. Air removal from a brake hydraulic drive
   17.37. Air removal from a brake hydraulic drive manually
   17.38. The valve for air removal from the block of modulators
   17.39. Electromagnetic valves of modulators
   17.40. The block of hydraulic modulators with electric motors
   17.41. Electronic control unit braking
   17.42. Sensor of angular speed of a forward wheel
   17.43. Flexible conducting of DUS of a forward wheel
   17.44. Sensor of angular speed of a back wheel
   + 17.45. Flexible conducting of DUS of a back wheel
   17.46. System electric safety lock
   17.47. ABS relay
   17.48. Signaling devices
+ Body
+ Heating, ventilation
+ Electric equipment


8128da4b cam chat



17.35. Anti-blocking system of brakes

GENERAL INFORMATION

The modulator of a forward wheel – the main mode of braking

AND. THE MODULATOR ENTRANCE (FROM THE MAIN BRAKE CYLINDER)
CENTURY. THE MODULATOR EXIT (TO THE WHEEL CYLINDER)

501. NORMALLY OPEN ЭМК (IN OPEN SITUATION)
502. THE RETURN BALL VALVE (IN OPEN SITUATION)
503. PISTON
516. THE MODULATOR CASE WITH THE ELECTROMECHANICAL DRIVE

Spring brake

505. SPRING LOCK RING
506. GEAR WHEEL LEADING
507. GEAR WHEEL CAM
508. BRAKE SPRING
509. LEADING KULACHKOVY COUPLING
510. ELECTRIC MOTOR SHAFT
511. ELECTRIC MOTOR CASE

The modulator of a forward wheel – braking at ABS work

AND. THE MODULATOR ENTRANCE (FROM THE MAIN BRAKE CYLINDER)
CENTURY. THE MODULATOR EXIT (TO THE WHEEL CYLINDER)

501. NORMALLY OPEN ЭМК (IN THE CLOSED POSITION)
502. THE RETURN BALL VALVE (IN THE CLOSED POSITION)
503. PISTON
516. THE MODULATOR CASE WITH THE ELECTROMECHANICAL DRIVE

The modulator of back wheels – braking at ABS work

AND. THE MODULATOR ENTRANCE (FROM THE MAIN BRAKE CYLINDER)
CENTURY. THE MODULATOR EXIT (TO THE WHEEL CYLINDER)

502. THE RETURN BALL VALVE (IN THE CLOSED POSITION)
503. PISTON
516. THE MODULATOR CASE WITH THE ELECTROMECHANICAL DRIVE

List of reductions

АБС
Anti-blocking system
B +
Tension of the storage battery
KN
Malfunction code
ТЭБУ
Electronic control unit braking
ЭМК
Electromagnetic valve

At emergency braking when blocking of wheels is most probable, the electronic control unit braking (TEBU) carries out automatic control of pressure of brake liquid in a drive of each forward wheel (individually) and in a drive of back wheels (synchronously). TEBU provides braking of wheels without blocking and by that reduces risk of drift of the car, improves stability and controllability of the car at emergency braking. It should be noted that the ABS VI system cannot increase pressure of brake liquid in wheel cylinders in comparison with pressure in the main brake cylinder which completely depends on effort on a brake pedal. ABS functions in a range of speeds from 5 km/h till the maximum speed of the car.

At office braking in usual road conditions the Brake system works in the main mode: by pressing a brake pedal the vacuum amplifier turns on and pistons of the main brake cylinder force brake liquid in wheel cylinders. Each of two ABS channels serving forward wheels, includes the separate modulator with an electromechanical drive. The modulator consists of the case in which hydraulic channels, the electromagnetic valve (EMK), the return ball valve, the piston with a ball nut and the running screw are executed. The electromechanical drive consists of the electric motor, a spring brake and shesterenny transfer. In the main mode of braking the piston is in extreme top situation. Moving of the piston to this situation is provided with an electromechanical drive by means of sharikovintovy transfer. For piston fixing the spring brake serves in the top situation. The brake consists of a spiral spring with two pads unbent inside which is inserted with a small gap into cylindrical boring of the case of the electric motor. The spring is put on a shaft of the engine and is between the leading kulachkovy coupling and a gear wheel with the face kulachkovy coupling. Cams of the leading coupling and a gear wheel are hooked with the corresponding pads of a spring (see fig. Spring brake). In the main mode of braking the piston from brake liquid is affected by the force directed down. This force will be transformed by the sharikovintovy mechanism to a torque which is transferred to a gear wheel of the engine and a spring of a brake and operates counter-clockwise. The torque causes a zakrutka and radial expansion of the spring which rounds rest against a wall of boring and brake a gear wheel. The piston, being in the top situation, opens the return ball valve. When braking brake liquid passes in the main mode to the wheel cylinder on two channels: via the return valve opened by the piston also EMK also are normally open. It provides possibility of braking of the car at ABS refusal (the piston does not come back to the top situation) or at a system de-energization (see fig. The modulator of a forward wheel – the main mode of braking).

The modulator of back wheels works similarly except for the following features. Both back wheels cope synchronously and, besides, in a design of the modulator there is no EMK. Synchronous management of braking of back wheels allowed to apply one electromechanical drive instead of two and to simplify ABS design. The principle of "Select Low" which provides a simultaneous rastormazhivaniye of both back wheels at the beginning of blocking of any of them is applied to management of braking of back wheels. This principle provides good cross-section stability of the car when braking. Absence in the modulator of back wheels of EMK is caused by that the contribution of back wheels to efficiency of braking is rather insignificant and at ABS refusal the car can be braked with the set delay by one forward wheels. At refusal of ABS which puts out of action brake contours of back wheels, TEBU establishes the corresponding code of malfunction and includes both signaling devices: yellow "ABS" and red "BRAKE".

ABS starts to work only at the included stoplight after the TEBU microprocessor will find the blocking beginning at least one of car wheels. In this case TEBU carries out by means of the modulator regulation of pressure of brake liquid in a brake contour соответ a stvuyushchy wheel (or wheels) for the purpose of prevention of its blocking and preservation of stability and controllability of the car. Cycles of regulation of pressure repeat several times in a second. It should be noted that the ABS VI system cannot increase pressure of brake liquid in wheel cylinders in comparison with pressure in the main brake cylinder which completely depends on effort on a brake pedal. As a result of application of ABS brake efficiency, and also course controllability and controllability of braking in various road conditions improves. At the beginning of blocking of wheels of TEBU operates turning on of electric motors and EMK of three modulators. At turning on of the modulator of a forward wheel of EMK at the command of TEBU closes section of one through passage of channels, I connect shchy the wheel brake cylinder to the main cylinder (see fig. The modulator of a forward wheel – braking at ABS work). Then TEBU regulates pressure in the isolated contour of a wheel, operating the electric motor of a drive of the piston of the modulator. At turning on of the electric motor the brake spring twists with simultaneous radial compression of rounds and releases a leading gear wheel (see fig. Spring brake). When lowering piston the return valve is closed, completely disconnecting the wheel brake cylinder from the main cylinder. Pressure in the wheel cylinder depends on volume of a nadporshnevy cavity of the modulator. Pressure reduction in a brake contour of a wheel is reached by lowering of the piston of the modulator. For increase in pressure of brake liquid the piston rises up. Movement of the piston is carried out by sharikovintovy transfer and an electromechanical drive of the modulator. If the wheel started to be blocked on a slippery surface (for example, on ice) at small pressure in a brake drive, and then in a phase of a zatormazhivaniye of ABS it is a wheel got on a site of a surface of the road with high factor of coupling, the piston of the modulator will move to extreme top situation and will open the return valve. Thus pressure in the wheel cylinder will be defined by pressure in the main brake cylinder and effort on a brake pedal. The piston will remain in the top situation until pressure of brake liquid does not become sufficient for blocking of a wheel and ABS will not begin a new cycle of regulation. The maximum level of pressure in the wheel cylinder in the course of work of ABS is limited by pressure size in the main brake cylinder. If in the course of car braking at working ABS the driver reduces effort on a brake pedal, the return valve and a part of liquid from the wheel cylinder will open will flow in the main brake cylinder. At ABS shutdown the piston of the modulator comes back to the top situation and EMK (on modulators of forward wheels) opens. After that the Brake system continues to work in the main mode. The modulator of back wheels at inclusion of ABS works similarly except for absent EMK. Synchronous movings of pistons in the course of regulation of pressure of brake liquid are carried out by one electromechanical drive and sharikovintovy transfer. In working cylinders of back wheels identical pressure of brake liquid is supported approximately.

At inclusion of ignition the signaling device of "ABS" which dies away in 3 seconds lights up. ABS is automatically given in a ready state on reaching speed of the car of 8 km/h. Thus pistons move to extreme top situation. Moving of pistons and work of electromechanical drives of modulators can be accompanied by small noise. If the driver presses at this time a brake pedal, it can feel a little push of a pedal. Thus process of reduction of ABS in a ready state will be interrupted.

The standard Brake system is equipped with one red signaling device of "BRAKE". In ABS two signaling devices are used: red "BRAKE" and yellow "ABS".