Fig. 122. Shock absorbers of front and rear suspensions:
1 - lower eye; 2 - reservoir; 3 - cylinder; 4 - rod; 5, 36 - casing; 6 - upper shock absorber eye; 7 - reservoir nut; 8 - stem protective ring; 9 - rod protective ring gasket; 10 - rod seal cage; 11 - rod seal; 12 - reservoir sealing ring; 13 - rod guide bushing; 14 - limiting plate; 15 - bypass valve spring; 16 - bypass valve plate; 17 - piston ring; 18 - piston; 19 - throttle disc of the return valve; 20 - recoil valve discs; 21 - recoil valve plate; 22 - recoil valve nut washer; 23 - recoil valve spring; 24 - recoil valve nut; 25 - compression valve cage; 26 - compression valve spring; 27 - compression valve plate; 28 - compression valve throttle disc; 29 - compression valve discs; 30 - compression valve body; 31 - nut for fastening the upper end of the front suspension shock absorber; 32 - spring washer; 33 - shock absorber mounting cushion washer; 34 - pillows; 35 - spacer sleeve; 37 - rod buffer; 38 - rubber-metal hinge.
The cylinder 3 of the shock absorber is located inside the reservoir 2. The annular space between them is filled with liquid. Inside the working cylinder there is a rod 4 with a piston 18. The piston has vertical channels located along two circles. The channels on the small circle are closed from below by discs and the return valve, and on the large one - from above by a plate 16 of the bypass valve.
A compression valve is installed in the lower part of the cylinder. In the metal-ceramic body 30 of the valve there is a seat, to which the spring 26 presses through the plate 27 the disks 28 and 29. The disk 28 is a throttle, has a cutout through which the liquid is throttled at a low piston speed. In order to ensure the passage of liquid from the reservoir 2 to the cylinder 3 and back, in the lower part of the compression valve body there is a cylindrical groove and four vertical channels, and in the cage 25 there are six side and one central hole.
A guide bushing 13 is installed in the top of the cylinder, which is sealed in the reservoir by ring 12, and the rod outlet is sealed by gland 11 with collar 10. All parts located in the upper part of the cylinder are pressed by nut 7.
During the compression stroke, the liquid under the piston pressure, overcoming the resistance of the flat spring 15 of the bypass valve, flows from the under-piston space to the over-piston space. All the displaced liquid cannot pass in this way, since the retracted rod occupies part of the volume released by the piston, therefore the other part of the liquid, bending the inner edges of the disks 29, flows from the cylinder into the reservoir. With a smooth stroke of the rod, the force from the liquid pressure will be insufficient to press the inner edges of the disks 29 away from the plate, and the liquid will pass into the reservoir through the cutout of the throttle disk 28.
During the recoil stroke, pressure is created above piston 18, and vacuum is created under the piston. The liquid from the above-piston space, overcoming the resistance of spring 23, bends the outer edges of discs 20 of the recoil valve and flows into the lower part of the cylinder. In addition, due to the vacuum, part of the liquid from the reservoir, bending the outer edges of discs 29 of the compression valve, fills the lower part of the cylinder.
At low piston speeds, when the fluid pressure is insufficient to push the recoil valve discs, the fluid will be throttled through the side cutouts of the throttle disc, creating resistance to the recoil stroke.