Kayaba Industry Company, Ltd.

Kyb Corporation

Satoshi Chikamatsu

Toshihiro Mori

Yoshifumi Kobayashi

Shinichi Hagidaira

Tomoyasu Abe

Yasuhiro Inagaki

Ryosuke Kamakura

Kouichi Watanabe

A solenoid valve includes a main valve having a valve seat and a main valve body configured to open or close a main flow passage, a pilot passage that branches from the main flow passage, an orifice provided in the pilot passage, a back-pressure chamber configured to bias the main valve body to a closing direction by virtue of an internal pressure, a pilot valve configured to control an internal pressure of the back-pressure chamber, and a solenoid configured to control a valve opening pressure of the pilot valve. There is a time difference between a valve opening timing of the main valve and a valve opening timing of the pilot valve such that the valve opening timing of the main valve is delayed from the valve opening timing of the pilot valve.

Solenoid valve

A solenoid valve includes a valve seat provided in a main flow passage, a main valve body configured to open or close the main flow passage, a pilot passage that branches from the main flow passage, an orifice provided in the pilot passage, a back-pressure chamber connected to the pilot passage downstream from the orifice to bias the main valve body to a closing direction by virtue of an internal pressure, a pilot valve disposed in the pilot passage downstream from a connection point to the back-pressure chamber to control an internal pressure of the back-pressure chamber, a solenoid configured to control a valve opening pressure of the pilot valve, and a second orifice provided between the back-pressure chamber and the pilot valve.

A port () allows a fluid to flow from a first fluid chamber () to a second fluid chamber () separated by the piston () of a shock absorber via a damping valve (). A flow sectional area of a passage () connecting the first fluid chamber () to the port () is reduced by a throttle valve () according to a pressure in the first fluid chamber (). A pressure of a pressure chamber () and a biasing force of a plate spring () acts on the throttle valve () in an opposite direction to the pressure of the first fluid chamber (). The hydraulic shock absorber is thereby caused to generate different damping force characteristics depending on a stroke speed of the piston ().

Damping force generating mechanism for hydraulic shock absorber

A shock absorber comprises a first passage () and a second passage () connecting a first fluid chamber () and a second fluid chamber (). A throttle () narrows an inflow of fluid to the first passage () according to an applied displacement pressure. The displacement pressure includes a fluid pressure in one of the two fluid chambers () and a pressure that depends on a velocity of the fluid flow through the throttle (). A spring () biases the throttle () in the opposite direction to narrow the fluid flow. The second passage () comprises a pair of orifices (). By exerting a pressure between the pair of orifices () on the throttle () in the opposite direction to narrow the fluid flow, the spring load required of the spring () is reduced.

Damping force generating mechanism for shock absorber

A damping valve () resists a flow of fluid from a first fluid chamber () to a second fluid chamber () which are separated by a piston (). A partitioning member (-) partitions an inflow space (A, B) of a passage () in the first fluid chamber (). A spool () decreases a flow cross-sectional area of a flow path from the first fluid chamber () into the inflow space (A, B) according to a differential pressure between the fluid chambers. By ensuring a gap between the outer circumference of the valve disk () and the partitioning member (-) which permanently allows fluid to flow from the first chamber () into the inflow space (A, B), the damping force characteristic in a high speed region of piston displacement can be set independently of the damping force characteristic in other regions.

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Tokyo, Japan

Satoshi Chikamatsu