Tube and shock absorber

Patent metadata

Field	Value
Publication number	US-9707820-B2
Application number	US-201414779645-A
Country	US
Kind code	B2
Filing date	Mar 25, 2014
Priority date	Apr 26, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A tube having sealing ring grooves formed by a sequential rotational process and a shock absorber including the tube, in which durability of a sealing ring fitted in each of the sealing ring grooves is enhanced. An inclination angle (θ 1 ) formed with respect to a plane (PL 1 ) perpendicular to an axis of a separator tube by a side surface of the sealing ring groove, which is located on an opening end side of the separator tube, is set to 8° or more. With this, a maximum tensile stress to be applied to an O-ring can be reduced to be smaller than a maximum tensile stress in a case of using a backup ring. As a result, the durability of the O-ring can be set equivalent to or enhanced to be higher than durability in the case of using the backup ring.

First claim

The invention claimed is:

1. A shock absorber to be mounted between two members movable relative to each other, the shock absorber comprising:
a cylinder having a working fluid sealed therein;
a piston inserted into the cylinder;
a piston rod coupled to the piston so as to extend to an outside of the cylinder;
an outer tube arranged at an outer periphery of the cylinder;
a separator tube provided to surround the outer periphery of the cylinder, the separator tube having a cylindrical side wall forming an annular passage communicating to an inside of the cylinder;
a reservoir formed on an outside of the separator tube between the cylinder and the outer tube, the reservoir having the working fluid and a gas sealed therein; and
a damping force generating mechanism arranged on an outside of the outer tube,
wherein the separator tube has a sealing ring groove formed so as to extend in a circumferential direction of the separator tube, so that an outer periphery of the end portion side of the separator tube is expanded circumferentially, and an inner periphery of an end portion side of the separator tube is concave, and
wherein the seal ring groove has a pair of side surfaces facing each other across a sealing ring so that a distance between the pair of the side surfaces is not narrowed but is widened from a bottom of the sealing ring groove toward an opening of the sealing ring groove,
an inclination angle formed in a direction in which the distance between the side surfaces is widened with respect to a plane perpendicular to an axis of the separator tube by one of the pair of side surfaces of the sealing ring groove facing each other across the sealing ring, which is located on an opening end side of the separator tube, is larger than an inclination angle formed by the other one of the pair of side surfaces, which is located on an opposite side to the opening end side of the separator tube.

2. A shock absorber according to claim 1 , at least one of the pair of side surfaces forming the inclination angle of 5° or more with respect to a plane perpendicular to an axis of the tube.

3. A shock absorber according to claim 2 , wherein the inclination angle is set to 8° or more.

4. A shock absorber according to claim 2 , wherein the inclination angle is set to 30° or less.

5. A shock absorber according to claim 1 , wherein the at least one of the pair of side surfaces and an inner surface of the tube are connected to each other at a connecting portion having a radius of curvature of a round surface of 0.2 mm or more.

6. A shock absorber according to claim 2 , wherein the at least one of the pair of side surfaces and an inner surface of the tube are connected to each other at a connecting portion having a radius of curvature of a round surface of 0.2 mm or more.

7. A shock absorber according to claim 3 , wherein the at least one of the pair of side surfaces and an inner surface of the tube are connected to each other at a connecting portion having a radius of curvature of a round surface of 0.2 mm or more.

8. A shock absorber according to claim 1 , wherein the sealing ring groove is formed by a sequential rotational process.

9. A shock absorber according to claim 2 , wherein the sealing ring groove is formed by a sequential rotational process.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Yamashita Mikio
• Nishimura Makoto

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

• F16F9/06

  using both gas and liquid {(F16F9/486 take precedence; self-pumping fluid springs B60G17/044)} · CPC title

• F16J15/062

  characterised by the geometry of the seat · CPC title

• B21D17/04

  by rolling · CPC title

• F16F9/36 Primary

  Special sealings, including sealings or guides for piston-rods ({F16F9/325, F16F9/3485 take precedence; arrangements for filling via piston rod sealing or guiding means F16F9/432} ; sealing of moving parts in general F16J15/16 - F16J15/56) · CPC title