Hydraulic shock absorber of a damping force adjustable type

摘要

A hydraulic shock absorber of a damping force adjustable type generates a damping force by controlling the flow of an oily fluid caused to occur by the slidable movement of the piston in the cylinder by means of a subsidiary disc valve, a main disc valve and a disc valve mounted on the plunger. The damping force is controlled directly regardless of the piston speed by controlling the relief pressure of the disc valve in accordance with an electric current applied to a coil. The pressure in a back pressure chamber is varied with the relief pressure of the disc valve and the pressure for opening the main disc valve is controlled, thereby extending the scope of controlling the damping force. Further, an excessive rise in the damping force can be controlled due to a rapid input, and an impact can be absorbed by allowing the disc valve to bend and relieving oily fluid in the back pressure chamber.