Electrically controlled shock absorber

摘要

An electrically controlled shock absorber includes a pumping unit which provides unidirectional fluid flow through an electrically controlled valve apparatus. The electrically controlled valve apparatus is contained in a housing external to the pumping unit in a housing defining an inlet chamber and a control chamber. A horizontally reciprocable inlet valve member controls fluid flow from the pumping unit into the inlet chamber, from which it can flow unimpeded to a reservoir chamber. The inlet valve member has an inlet orifice therethrough to allow fluid flow into the control chamber, create a pressure drop across the inlet valve member effective to cancel a constant closing bias thereon, and damp inlet valve member movement. An electromagnetically controlled pilot valve in an outlet from the control chamber to the reservoir chamber produces a control pressure in the control chamber as a function of an input electric current. The inlet valve opens as necessary to ensure that the pressure of the fluid pumped out of the pumping unit substantially equals the control pressure. The damping force is thus a function of input current independent of fluid flow rate. The pilot valve is designed for stable operation.