|
|
The Exhaust System:
Direct Acting Shock Absorber
The shock absorber most widely used is the direct-acting shock absorber. These shocks are often referred to as airplane-type shocks. The direct-acting shock is mounted directly to both the vehicle frame and the axle or suspension arm. As the frame rises and falls in relation to the axle, the shock absorber must telescope out and in. The shock's resistance to telescopic movement dampens (hinders or slows down) this up-and-down movement. The shock may have eyes made on its ends for mounting, or it may have threaded studs. Rubber bushings are used inside the eyes and rubber grommets on the studs to prevent metal-to-metal contact and to provide flexible mounting.
The direct-acting shock absorber consists of an inner cylinder, an outer cylinder, a piston, a piston rod, and, in most cases, an outer dust-and-rock shield. A series of valves in the piston and at the bottom of the inner cylinder control the movement of oil within the shock. A reservoir which contains a supply of oil surrounds the inner cylinder.
The direct-acting shock absorber is double-acting. When the vehicle spring is compressed, the shock absorber telescopes in (gets shorter). This moves the piston down, putting pressure on the oil under the piston. For the piston to continue to move downward, it is necessary for the oil to pass through the compression valve. Oil flows through the compression valve into the upper section of the inner cylinder. Oil flow and spring compression are regulated by the size of the compression valve port holes and the spring.
When the spring rebounds, the piston is moved up and down. The oil trapped above the piston must travel through the rebound valve. To make up for the reduced amount of rod that is now in the inner cylinder, additional fluid is pulled in from the reservoir through the intake valve. Oil flow and spring movement is regulated by the size of the rebound valve opening and its spring. Sometimes a series of valves is used to provide better regulation of the oil flow in the shock absorber to produce a smoother ride. |
|
|
|
|
|
or
Get your free AutoSpeedNet Account Today
 Home
Forums
Introduction
3DAuto Toolbox
 Articles
When Parts Go Bad
Glossary
Article Pages
1. Suspension System
2. Principles Of Suspension Systems
3. Frame Construction
4. Types of Suspension Systems
5. Construction Of Leaf Springs & Shackles
6. Coil Springs
7. Torsion Bar Suspension
8. Auxilary Spring Suspension
9. Variable-load Spring Arrangement
10. Bogie-Type Suspension
11. Shock Absorber Introduction
12. Hydraulic Shock Absorber Operation
Hot Topics
-> Suspension Problems Can Mean More Than a Rough Ride.
|