Controllable shock absorber, particularly for motor vehicles

摘要

Controllable motor-vehicle shock absorbers are provided with a damper cylinder (1) containing a rheoelectrical damping fluid, a piston rod (2) which plunges into the said cylinder in a sealed manner, a working piston (3) which is arranged on the inner end of the said rod and divides the cylinder space into two working chamber halves (4, 5), at least one connecting passage (13, 14) connecting the two halves to one another and allowing a flow of damping fluid during the movements of the working piston, and a pair (12) of electrodes which are installed in the said passage(s), can be connected to a controllable electric high voltage and serves for the variation of the viscosity of the rheoelectrical damping fluid in its electrostatic field. In order to ensure that the shock absorber will still provide an adequate damping force and thus remain adequate for driving purposes even if the high voltage supplied to its electrodes (12) fails, an electromagnetically actuable emergency-running valve (15) is installed in the connecting passage (13, 14), the said valve responding if the high voltage to the electrodes fails and thereby increasing the flow resistance of the connecting passage (13, 14). <IMAGE>