Patent ID: 9506520
Filing Date: 2016-11-29
CPC Classification: F16F

Claim Text:
1. A damping force variable valve assembly, which is installed in a damping force variable shock absorber to adjust a damping force of the shock absorber, the damping force variable valve assembly comprising: a solenoid configured to generate a magnetic force when an electric current is applied thereto; a spool configured to be moved by the magnetic force of the solenoid; a spool guide configured to surround the spool so as to guide a movement of the spool; a valve body which is disposed around the spool guide; a main valve which is installed to cover a main passage formed in the valve body and generate a damping force; a back pressure chamber which is formed to have a back pressure pressurizing the main valve from the back of the main valve; a chamber forming body which is installed outside the valve body to form the back pressure chamber; and an elastic opening/closing portion which is installed in the valve body to open and close a pressure adjustment passage communicating the inside of the back pressure chamber with the outside of the back pressure chamber, wherein as a flow path within the damping force variable valve assembly is changed by interaction between the spool and the spool guide, the damping force of the shock absorber is variable between a hard mode in which the back pressure of the back pressure chamber is increased and a soft mode in which the back pressure of the back pressure chamber is decreased, wherein, in a case where a flow velocity of a working fluid is low in the hard mode, the elastic opening/closing portion opens the pressure adjustment passage when an internal pressure of the back pressure chamber exceeds a preset pressure, wherein the elastic opening/closing portion includes a blocking member configured to block the pressure adjustment passage, and an elastic member configured to elastically support the blocking member and to be deformed when the internal pressure of the back pressure chamber exceeds the preset pressure and open a flow passage by the blocking member and the elastic member, wherein the elastic opening/closing portion is disposed on an exit side of the pressure adjustment passage in the valve body, and a concave portion which is connected to the pressure adjustment passage is formed in the valve body such that the elastic opening/closing portion is disposed therein, wherein the blocking member has a ring shape, wherein the pressure adjustment passage is plurally provided and the plurality of pressure adjustment passages are circularly arranged in the valve body, wherein the concave portion is formed to have a circular shape to connect all the pressure adjustment passages, and wherein the blocking member having the ring shape is disposed to close all the pressure adjustment passages circularly arranged in the valve body.