Patent ID: 6032933
Filing Date: 2000-03-07
Classification: B60G,Y10S

Abstract:
A vehicular self-pumping hydropneumatic spring strut having internal level regulation for controlling the height of a vehicle body, said spring strut comprising:a work cylinder filled with oil and divided into a high-pressure work cavity and a low-pressure work cavity by a work piston carried by a hollow piston rod movable into and out of said work cylinder, said work cylinder being pressurized by a gas communicated to said high-pressure work cavity;a piston pump having a pump cylinder formed by said hollow piston rod and being configured for communicating oil between said a low-pressure work cavity and said high-pressure work cavity;a pump rod fastened to said work cylinder and configured to penetrate into said pump cylinder as said piston rod moves into and out of said work cylinder, said pump rod having a generally conically shaped tip having a length that defines a regulating area of said spring strut, said high-pressure work cavity and said pump cylinder being fluidly connected when said work piston is positioned approximately at said regulating area, said regulating area being fluidly closable by a sealing engagement created between said pump rod and said work piston as said piston rod is moved into said work cylinder and past said regulating area;a first nonreturn valve located in said work piston and configured to fluidly connect said pump cylinder with said low-pressure work cavity;a second nonreturn valve located in said work piston and configured to fluidly connect said pump cylinder with said high-pressure work cavity; anda valve located between said high-pressure work cavity and said pump cylinder and configured to block said first nonreturn valve so as to fluidly disconnected said low-pressure work cavity and said pump cylinder when said piston rod is moved out of said work cylinder, said valve unblocking said first nonreturn valve so as to fluidly connect said low-pressure work cavity and said pump cylinder when said piston rod is moved into said work cylinder.