IP Library › Patent Application 14431772
Patent Application
App. No. 14/431,772

SHOCK ABSORBER

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Quick Facts
Patent No.
US None
App. No.
14/431,772
Abstract

A shock absorber includes a cylinder, a piston, a piston rod, an expansion-side passage that allows a fluid to flow only from an expansion-side chamber toward a contraction-side chamber, a contraction-side passage that allows the fluid to flow only from the contraction-side chamber toward the expansion-side chamber, an expansion-side damping valve that applies resistance to a flow of fluid passing through the expansion-side passage, a contraction-side damping valve that applies resistance to a flow of fluid passing through the contraction-side passage, an expansion-side bypass passage that connects the expansion-side chamber to the contraction-side chamber, an expansion-side relief valve that is opened by pressure in the expansion-side chamber so as to open the expansion-side bypass passage, a contraction-side bypass passage that connects the expansion-side chamber to the contraction-side chamber, and a contraction-side relief valve that is opened by pressure in the contraction-side chamber so as to open the contraction-side bypass passage.

Claims (29)

1 . A shock absorber comprising:

a cylinder;

a piston that is inserted into the cylinder slidably and divides an interior of the cylinder into an expansion-side chamber and a contraction-side chamber;

a piston rod that is inserted into the cylinder movably and connected to the piston;

an expansion-side passage that allows a fluid to flow only from the expansion-side chamber toward the contraction-side chamber;

a contraction-side passage that allows the fluid to flow only from the contraction-side chamber toward the expansion-side chamber;

an expansion-side damping valve that applies resistance to a flow of fluid passing through the expansion-side passage;

a contraction-side damping valve that applies resistance to a flow of fluid passing through the contraction-side passage;

an expansion-side bypass passage that connects the expansion-side chamber to the contraction-side chamber while bypassing the expansion-side passage;

an expansion-side relief valve that is provided midway in the expansion-side bypass passage, and is opened by pressure in the expansion-side chamber so as to open the expansion-side bypass passage;

a contraction-side bypass passage that connects the expansion-side chamber to the contraction-side chamber while bypassing the contraction-side passage; and

a contraction-side relief valve that is provided midway in the contraction-side bypass passage, and is opened by pressure in the contraction-side chamber so as to open the contraction-side bypass passage.

2 . The shock absorber as defined in claim 1 , wherein a valve opening pressure of the expansion-side relief valve is set to be higher than a valve opening pressure of the expansion-side damping valve, and a valve opening pressure of the contraction-side relief valve is set to be higher than a valve opening pressure of the contraction-side damping valve.

3 . The shock absorber as defined in claim 1 , wherein the expansion-side relief valve comprises:

an expansion-side valve disc that includes an expansion-side bypass port and is attached to an outer periphery of the piston rod; and

an expansion-side valve body laminated onto the expansion-side valve disc in order to open and close the expansion-side bypass port,

the contraction-side relief valve comprises:

a contraction-side valve disc that includes a contraction-side bypass port and is attached to the outer periphery of the piston rod; and

a contraction-side valve body laminated onto the contraction-side valve disc in order to open and close the contraction-side bypass port,

the piston rod comprises a shared passage that communicates with one of the expansion-side chamber and the contraction-side chamber,

the expansion-side bypass passage is formed to include the shared passage and the expansion-side bypass port, and

the contraction-side bypass passage is formed to include the shared passage and the contraction-side bypass port.

4 . The shock absorber as defined in claim 3 , wherein the piston is attached to the outer periphery of the piston rod,

the expansion-side relief valve is attached to the outer periphery of the piston rod further toward the contraction-side chamber side than the piston,

the contraction-side relief valve is attached to the outer periphery of the piston rod further toward the contraction-side chamber side than the expansion-side relief valve,

the piston, the expansion-side relief valve, and the contraction-side relief valve are fixed to the piston rod by a piston nut that is screwed to a tip end of the piston rod, and

the contraction-side valve body is laminated onto the expansion-side chamber side of the contraction-side valve disc.

5 . The shock absorber as defined in claim 1 , wherein the piston is attached to an outer periphery of the piston rod, and

the expansion-side relief valve and the contraction-side relief valve are attached to the outer periphery of the piston rod further toward the expansion-side chamber side than the piston.

Assignments (2)
CHANGE OF NAME Recorded Dec 21, 2015
From: KAYABA INDUSTRY CO., LTD.
To: KYB CORPORATION
Reel/Frame 037355/0142 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 23, 2015
From: TERAOKA, TAKASHI; INAMITSU, KAZUTAKA; KAWAKAMI, HIDEKI
To: KAYABA INDUSTRY CO., LTD.
Reel/Frame 035485/0223 →