Cylinder device

Patent metadata

Field	Value
Publication number	US-9945441-B2
Application number	US-201515124866-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Oct 17, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A cylinder device includes a recess provided on either one of the piston and the cylinder, the recess facing the other one of the piston and the cylinder; an extension-side discharge passage configured to permit only a flow of liquid from the extension-side chamber toward the recess; a compression-side discharge passage configured to permit only a flow of liquid from the compression-side chamber toward the recess; a tank-side discharge passage configured to allow the extension-side discharge passage and the compression-side discharge passage to communicate with the tank through the recess; an extension-side damping force generation passage configured to apply a resistance to a flow of liquid passing therethrough so as to exert a damping force during extension; and a compression-side damping force generation passage configured to apply a resistance to a flow of liquid passing therethrough so as to exert a damping force during contraction.

First claim

The invention claimed is:

1. A cylinder device, comprising:
a cylinder;
a piston slidably inserted into the cylinder;
a rod inserted into the cylinder and connected to the piston;
an extension-side chamber and a compression-side chamber partitioned by the piston within the cylinder;
a tank;
an extension-side suction passage configured to permit only the passage of liquid from the tank toward the extension-side chamber;
a compression-side suction passage configured to permit only the passage of liquid from the tank toward the compression-side chamber;
a recess provided on either one of the piston and the cylinder, the recess facing the other one of the piston and the cylinder;
an extension-side discharge passage provided in the piston and configured to permit only a flow of liquid from the extension-side chamber toward the recess;
a compression-side discharge passage provided in the piston and configured to permit only a flow of liquid from the compression-side chamber toward the recess;
a tank-side discharge passage configured to allow the extension-side discharge passage and the compression-side discharge passage to communicate with the tank through the recess;
an extension-side damping force generation passage configured to apply a resistance to a flow of liquid passing therethrough so as to exert a damping force during extension; and
a compression-side damping force generation passage configured to apply a resistance to a flow of liquid passing therethrough so as to exert a damping force during contraction.

2. The cylinder device according to claim 1 , wherein
the extension-side damping force generation passage is an extension-side damping passage configured to apply a resistance to a flow of liquid from the extension-side chamber toward the tank, and
the compression-side damping force generation passage is a compression-side damping passage configured to apply a resistance to a flow of liquid from the compression-side chamber toward the tank.

3. The cylinder device according to claim 1 , wherein
the extension-side damping force generation passage is an extension-side communication passage configured to apply a resistance to a flow of liquid from the extension-side chamber toward the compression-side chamber, and
the compression-side damping force generation passage is a compression-side damping passage configured to apply a resistance to a flow of liquid from the compression-side chamber toward the tank.

4. The cylinder device according to claim 1 , wherein
the extension-side damping force generation passage is an extension-side damping passage configured to apply a resistance to a flow of liquid from the extension-side chamber toward the tank, and
the compression-side damping force generation passage is a compression-side communication passage configured to apply a resistance to a flow of liquid from the compression-side chamber toward the extension-side chamber.

5. The cylinder device according to claim 1 , wherein
the rod is inserted into the cylinder such that both ends of the rod protrude to the outside of the cylinder, and the piston is connected to the middle of the rod,
the extension-side damping force generation passage is an extension-side communication passage configured to apply a resistance to a flow of liquid from the extension-side chamber toward the compression-side chamber, and
the compression-side damping force generation passage is a compression-side communication passage configured to apply a resistance to a flow of liquid from the compression-side chamber toward the extension-side chamber.

6. The cylinder device according to claim 1 , wherein
a thrust reducing stroke range in which the thrust is reduced is set by setting an axial direction width of the recess.

7. The cylinder device according to claim 1 , wherein
the recess is formed as an annular groove provided on the outer periphery of the piston,
the extension-side discharge passage allows the extension-side chamber to communicate with the annular groove, and
the compression-side discharge passage allows the compression-side chamber to communicate with the annular groove.

8. The cylinder device according to claim 1 , wherein
the piston comprises:
a first piston forming member provided on the rod and slidingly contacting the cylinder; and
a second piston forming member provided on the rod separately from the first piston forming member and slidingly contacting the cylinder, and wherein

the recess is formed as an annular gap formed between the first piston forming member and the second piston forming member,
the extension-side discharge passage allows the extension-side chamber to communicate with the annular gap, and
the compression-side discharge passage allows the compression-side chamber to communicate with the annular gap.

9. The cylinder device according to claim 1 , wherein
the recess is formed as an annular groove provided on an inner periphery of the cylinder, and
the tank-side discharge passage allows the tank to communicate with the recess.

10. The cylinder device according to claim 1 , comprising:
an opening and closing valve provided in the tank-side discharge passage and configured to communicate and shut off between the recess and the tank.

11. The cylinder device according to claim 1 , comprising:
a damping force generation element provided in the tank-side discharge passage and configured to apply a resistance to a flow of liquid from within the cylinder toward the tank.

12. The cylinder device according to claim 1 , comprising:
a tandem pump configured to supply a liquid at an identical flow rate to both the extension-side chamber and the compression-side chamber.

Assignees

• Kyb Corp

Inventors

• Ogawa Takayuki

Classifications

• F16F9/50

  Special means providing automatic damping adjustment, {i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs}(F16F9/53 takes precedence); {Special means providing self-adjustment of spring characteristics} · CPC title

• F16F9/46

  allowing control from a distance {, i.e. location of means for control input being remote from site of valves, e.g. on damper external wall (attachment of valve units to cylinders F16F9/325)} · CPC title

• F16F9/20

  with the piston-rod extending through both ends of the cylinder {, e.g. constant-volume dampers} · CPC title

• F16F9/19 Primary

  with a single cylinder {and of single-tube type} · CPC title

• F16F9/58

  Stroke limiting stops, e.g. arranged on the piston rod outside the cylinder (F16F9/49 takes precedence) · CPC title