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1. Flexible hose for clutch release. 2. Clutch release drive tube 3. Reservoir. 4. Clutch release master cylinder housing. 5. Master cylinder piston. 6. Fitting. 7. O-ring. 8. The piston of the pusher of the main cylinder. 9. Pedal axis. 10. Strengthening spring (servo spring). 11. Release spring. 12. Clutch pedal. 13. Pusher axis. 14. Clutch pedal pusher 15. Retaining ring. 16. Return spring. 17. Engine flywheel. 20. Clutch release clutch. 21. Clutch release fork. 22. Shutdown fork pusher. 23. Retractable fork spring. 24. The piston of the working cylinder. 25. The body of the working cylinder. 26. Union for bleeding the clutch drive. 27. Support plate. 28. Screw restrictive clutch pedal. h is the arm of the action of the force from the spring 10; a, b - holes in the main cylinder; c, d - holes in the piston; e - a hole for transferring pressure.
On VAZ vehicles, a hydraulic clutch release drive with an outboard pedal is used. Compared to a mechanical hydraulic drive, the clutch is smoother, easier to maintain, more durable and more efficient. Smooth engagement of the clutch reduces dynamic loads in the transmission and improves driving comfort.
Maintenance of the drive provides only the regulation of the free play of the clutch pedal and, if necessary, pumping the system.
The clutch pedal is installed in a special bracket for the clutch and brake pedals, mounted on the shield of the front of the car, and rotates on a fixed bushing clamped in the bracket by a central bolt common to the bushings of the clutch and brake pedals.
Two polyamide bushings are inserted into the pedal hub, which do not require lubrication during operation.
In the initial position, the pedal is held by the force of the withdrawal spring 11 and is pressed by it against the restrictive screw 28 with a rubber buffer. A pusher 14 is pivotally connected to the pedal, the spherical end of which is in contact with the piston 8 of the master cylinder pusher. Light contact of the piston with the pusher with a gap of not more than 0.1-0.5 mm corresponds to a pedal stroke of 0.4-2 mm and is regulated by the restrictive screw 28. The specified gap makes it possible, when the clutch is on, the master cylinder piston under the action of the spring 16 to rest against the retaining ring, i.e., take the initial position, which guarantees the communication of the working cavity of the main cylinder with the nutrient tank 3 through the bypass hole a.
Housing 4 of the master cylinder of the clutch release actuator is a cast iron with a flange for attaching to the pedal bracket. The main cylinder is closed at the front with a cork with a copper gasket, at the back - with a rubber protective cap. A protective cap, the inner shoulder of which is put on the pusher rod, and the outer one enters the groove on the body, protects the cylinder from dust. From above, in one of the tides of the main cylinder body, with the help of a steel retaining ring, a fitting 6 of a flexible hose coming from the supply tank 3 is installed. To seal the connection between the fitting and the body, a rubber ring is installed between them.
In another tide of the main cylinder body, the end of a bent steel tube 2 is fastened with a connecting nut.
The steel coiled, two-layer with a galvanized surface, the tube, together with its connecting nuts put on until the flaring of the ends, is part of the pipeline connecting the main and working cylinders of the clutch release drive.
The conical flaring of the ends of the tube and the shape of the butt end of the connecting nut, in combination with the conical surface of the body seat, ensure the tightness of the connection.
The second part of the clutch release pipeline is made of rubber flexible hose 1 with steel tips. A flexible rubber hose compensates for the change in the length of the pipeline associated with a change in the position of the power unit suspended on rubber cushions relative to the body.
Inside the main cylinder body there are a piston 8 of the pusher and a piston 5 of the main cylinder of the shutdown drive with a rubber sealing ring 7 between them. This design unloads the piston 5 of the main cylinder from radial loads when exposed to the pusher and allows, due to compression between the pistons 8 and 5 of the sealing ring 7, to prevent fluid from flowing out of the cylinder. Behind the piston 5, a working cavity of the cylinder is formed, at the outlet connected by a pipeline 2 to the working cylinder of the shutdown drive and communicating with the reservoir 3 with liquid through the overflow hole a, a fitting and a hose. Another ring 7 is installed in the piston groove 5, which seals the working cavity of the cylinder when the clutch is disengaged and acts as a valve in the master cylinder when the clutch is engaged (releasing the pedal).
When the clutch pedal is released, the pistons of the master cylinder under the action of the return spring 16 move after the pusher to their original position until they stop against the retaining ring 15.
When the pedal is suddenly released, the liquid returning from the working cylinder to the main one does not have time to fill the space vacated by piston 5, and a vacuum is created in the working cavity. Under the action of this rarefaction, the liquid through the inlet b, the gap in the groove along the rear end of the ring 7 (and at this time it is pressed against the front end of the groove) and the holes in the piston flows into the working cavity.
Subsequently, the excess amount of liquid, as it enters from the pipeline, is displaced from the working cavity through the bypass hole a into tank 3.
The cast iron clutch slave cylinder is fixed on the left side of the clutch housing with two bolts. In the body 25 of the working cylinder, a steel piston 24 is placed with two sealing rings, one of which is 7 (anterior), pressed through the support plate 27 by a spring, is the same as the sealing rings of the main cylinder. The spring constantly presses the ring 7, which improves its contact with the cylinder mirror, and, consequently, the sealing of the cylinder, especially in the absence of pressure in the system when the clutch is engaged.
When the clutch is disengaged, the pressure of the working fluid through the hole e of the piston presses ring 7 even more tightly against the cylinder mirror, improving its sealing.
The pusher 22 of the clutch release fork rests against the spherical recess of the piston 24, the length of which can be adjusted by rotating the tip fixed by the nut. The withdrawal spring 23 of the fork 21 of the clutch release through the tip constantly presses the pusher 22 to the piston and moves it into the cylinder, tending to the extreme forward position. Through the hole in the cork of the body 25, into which the tip of the flexible hose of the clutch drive is screwed, the liquid enters the working cylinder.
The working cylinder is protected from dirt by a rubber protective cap.
To remove air from the hydraulic drive system, fitting 26 is screwed into the body of the working cylinder, closed with a rubber cap to protect the internal channel of the fitting from clogging.
Clutch work. When you press the clutch pedal, the pusher 14 advances the pistons 8 and 5 of the master cylinder, compressing the spring 16.
As soon as the front sealing ring 7 closes the bypass hole a, pressure is created inside the cylinder in the working cavity, and the fluid passes through the tube 2 and hose 1 into the working cylinder, moving the piston 24. The driven piston 24 through the pusher 22 turns the clutch release fork 21, which leads to the selection of the gap between the thrust flange and the sleeve 20, and then to their joint movement. Thrust flange acts on the petals of the diaphragm pressure spring, deforms it (turns) on support rings. In this case, the outer edge of the spring removes the pressure plate 19 from the driven 18 by the clamps. The clutch is disengaged. The transmission of rotation from the engine to the gearbox is stopped.
When the clutch is disengaged, the release spring 23 of the fork and the release spring 11 of the clutch pedal are stretched. Reinforcing spring 10, connected to the pedal with a hook, reduces the force on the pedals when the clutch is released. Reinforcing spring 10 comes into operation as soon as its plane of action passes through the axis of rotation of the pedal.
As the pedal is further turned, the shoulder h of the action of the force from the spring 10 increases, increasing the moment that makes it easier to press the pedal.
When released, the clutch pedal under the action of the release spring 11 returns to its original position, and the pistons of the master cylinder under the action of the return spring 16 move after the pusher 14 of the pedal until it stops against the retaining ring 15. In this case, the pressure in the system drops and the clutch pressure plate under the action of the pressure spring approaches the driven disk 18 and, gradually straightening the wavy surface of the petals of the driven disk, presses it against the flywheel. The clutch engages smoothly. The crankshaft of the engine is connected to the input shaft of the gearbox. The clutch release clutch and the bearing sitting on it are retracted to their original position by the fork 21 under the action of the withdrawal spring 23, which, through the fork and the pusher 22, pushes the piston 24 in the cylinder 25 to the extreme forward position. When the piston moves, the fluid is displaced from the working cylinder and returns through the pipeline to working space of the master cylinder.