Abstract

A hydraulic shock absorber comprising a shock absorber tube enclosing a hollow piston rod which moves in an oscillating manner corresponding to successive compression stages and rebound stages. The piston rod connects to a working piston that divides the interior of the shock absorber tube into two working areas. A bypass connects the two working areas of the shock absorber tube. The piston slide valve which is used to block and release the bypass is actuated by the pressure of a control pressure medium. The piston slide valve contains a piston slide which can be displaced by the control pressure medium against the force of a restoring spring, and which blocks or releases the bypass. The shock absorber is configured to be switched to a lower damping effect of the rebound stage by means of a controlled pressure application and without changing the damping effect of the compression stage.

IPC Classes  ?

• F16F 9/512 - Means responsive to load action on the damper or fluid pressure in the damper
• F16F 9/346 - Throttling passages in the form of slots arranged in cylinder walls
• F16F 9/46 - Means on or in the damper for manual or non-automatic adjustmentSprings, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium Details such means combined with temperature correction allowing control from a distance
• F16F 9/516 - Special means providing automatic damping adjustment resulting in the damping effects during contraction being different from the damping effects during extension

Abstract

The invention relates to a hydraulic shock absorber comprising a shock absorber tube (1) into which a hollow piston rod (2) is immersed in an oscillating manner corresponding to successive compression stages (D) and rebound stages (Z), said piston rod being connected to a working piston (4) that divides the interior of the shock absorber tube (2) into two working areas (1a and 1b). In the process, a bypass which connects the two working areas (1a and 1b) of the shock absorber tube (1) runs through the working piston (4), wherein a piston slide valve (7) which is used to block and release the bypass and is actuated by the pressure of a control pressure medium is arranged in the path of the bypass, said piston slide valve containing a piston slide (7b) which can be displaced by the control pressure medium (S) against the force of a restoring spring (8) and which blocks or releases the bypass. The aim of the invention is to allow such a shock absorber to be switched to a lower damping effect of the rebound stage by means of a controlled pressure application and without changing the damping effect of the compression stage. For this purpose, the piston slide (7b) of the piston slide valve (7) has blocking positions for a faulty operation and for a heavy load operation, said blocking positions blocking the bypass at the beginning and at the end of the displacement path of the slide, and the piston slide is provided with at least one release position in the longitudinal region of the displacement path, said release position releasing the bypass. The bypass is additionally paired with a non-return valve (12) which prevents damping fluid from passing through the bypass during the compression stage (D) of the shock absorber and allows damping fluid to pass through the bypass during the rebound stage (Z) of the shock absorber.

IPC Classes  ?

• F16F 9/512 - Means responsive to load action on the damper or fluid pressure in the damper
• F16F 9/516 - Special means providing automatic damping adjustment resulting in the damping effects during contraction being different from the damping effects during extension
• F16F 9/346 - Throttling passages in the form of slots arranged in cylinder walls
• F16F 9/46 - Means on or in the damper for manual or non-automatic adjustmentSprings, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium Details such means combined with temperature correction allowing control from a distance
• B60G 17/015 - Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
• F16F 9/18 - Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts with a closed cylinder and a piston separating two or more working spaces therein