Method of manufacturing cylinder apparatus

Patent metadata

Field	Value
Publication number	US-9309947-B2
Application number	US-201213622619-A
Country	US
Kind code	B2
Filing date	Sep 19, 2012
Priority date	Sep 28, 2011
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

When manufacturing a disk valve having a ring-shaped elastic seal member fixed to one side thereof for use in a cylinder type hydraulic shock absorber, a disk valve blanked from a plate material is set on a bottom of a lower mold member that is curved to be convex on one side. Mold clamping is performed to form a cavity by a cylindrical mold part and to press the disk valve with a press part to deform the disk valve into a shape that is convex on one side. In this state, the cavity is filled with a rubber material through a passage and vulcanized and cured to mold and fix an elastic seal member to the disk valve. At this time, the disk valve is deformed in a direction in which the curvature reduces by shrinkage of the rubber material.

First claim

What is claimed is:

1. A method of manufacturing a cylinder apparatus, the cylinder apparatus including:
a cylinder having a fluid sealed therein;
a piston slidably fitted in the cylinder;
a piston rod connected to the piston; and
a valve device adapted to regulate a flow of fluid caused by sliding movement of the piston to generate a pressure difference;
wherein the valve device includes an annular disk valve having an annular elastic seal member fixed to at least one side thereof;
the method comprising:
the step of fixing the elastic seal member to the disk valve, the step including:
a deforming step of deforming the disk valve in such a manner that a surface on one side is convex and a surface on an opposite side is concave; and
a fixing step of fixing the elastic seal member to the surface on the convex side of the disk valve deformed in the deforming step,
wherein a correcting force with which the one side surface of the disk valve is deformed into a convex shape is at such a level that the disk valve is deformed to be convex on the one side when the elastic seal member is removed therefrom, and
wherein the elastic seal member is shrunk after being fixed to apply a force for deforming the surface of the disk valve on the concave side to deflect the disk valve, thereby making the surfaces of the disk valve on the convex side and the concave side substantially flat.

2. The method of claim 1 , wherein the elastic seal member is formed of a rubber material having fluid-tight properties and slidability.

3. The method of claim 1 , wherein the deforming step includes a step of pressing the disk valve against a concave or convex mold.

4. The method of claim 3 , wherein the mold is a mold for molding the elastic seal member.

5. The method of claim 1 , wherein an inner peripheral portion of the disk valve is clamped, and the surface on the concave side of an outer peripheral portion of the disk valve seats on a seat portion of the piston and opens from the seat portion;
the elastic seal member is slidably fitted into a valve member disposed at a back of the disk valve to form a back-pressure chamber in the valve member, wherein a pressure in the back-pressure chamber acts on the disk valve in a direction for closing the disk valve.

6. The method of claim 5 , wherein the elastic seal member includes an outer peripheral portion tapered so that a diameter thereof increases with a distance from the disk valve.

7. A method of manufacturing a shock absorber, the shock absorber comprising:
a cylinder having a fluid sealed therein;
a piston slidably fitted in the cylinder;
a piston rod connected to the piston; and
a damping valve device adapted to control a flow of fluid caused by sliding movement of the piston, the damping valve device including an annular disk valve having an annular elastic seal member of rubber material fixed to one side thereof;
the method comprising:
fixing the elastic seal member to the disk valve, including:
a deforming step of deforming the disk valve in such a manner that a surface on one side is convex and a surface on an opposite side is concave; and
a fixing step of fixing the elastic seal member to the convex side of the disk valve deformed in the deforming step by vulcanization and curing,
wherein an elastic seal member is not provided on the concave side of the disk valve,
wherein a correcting force with which the one side surface of the disk valve is deformed into a convex shape is at such a level that the disk valve is deformed to be convex on the one side thereof when the elastic seal member is removed therefrom, and
wherein the disk valve is deformable according to shrinkage of the elastic seal member at the time of the curing after vulcanization.

8. The method of claim 7 , further comprising the steps of:
providing a first mold member and a second mold member;
the first mold member being shaped in a cylinder, one end of which is closed, to form a bottom and outer periphery of a cavity, the bottom of the first mold member being curved at a predetermined curvature or sloped at a predetermined angle so that a center of the bottom projects convexly;
the second mold member having a mold part fittable into the first mold member, the mold part adapted to abut at a distal end thereof against the disk valve set in the first mold member to form the cavity when the first mold member and the second mold member are closed,
the second mold member being provided with a passage for filling the cavity with a rubber material to form an elastic seal member, the distal end of the mold part, which abuts against the disk valve, being curved or sloped in conformity to the curvature or angle of the bottom of the first mold member;
the method further comprising the steps of:
setting a disk valve blanked from a plate material on the bottom of the first mold member;
closing the first mold member and the second mold member to form the cavity by the mold part and to press and deform the disk valve into a shape that is convex on one side;
filling a rubber material into the cavity through the passage and vulcanizing and curing the rubber material to mold and fix an elastic seal member to the disk valve; and
opening the first mold member and the second mold member after the rubber material in the cavity has been cured, and removing the disk valve having the elastic seal member fixed thereto.

9. The method of claim 8 , wherein the bottom of the first mold member is slightly larger in diameter than the disk valve.

10. The method of claim 9 , wherein the first mold member has a core stood in a center of the bottom thereof to position the disk valve, whereby the first mold member is provided with a cylindrical portion;
the mold part of the second mold member is a cylindrical mold part fittable into the cylindrical portion of the first mold member.

11. The method of claim 10 , wherein, when the first mold member and the second mold member are closed, the core of the first mold member is inserted through an opening of the disk valve to position the disk valve concentrically with respect to the cavity.

12. The method of claim 11 , wherein the second mold member has a cylindrical press part inserted between the cylindrical mold part and the core of the first mold member to abut against the disk valve set in the first mold member.

13. The method of claim 12 , wherein the press part has a distal end abuttable against the disk valve, the distal end being curved or sloped in conformity to the curvature or angle of the bottom of the first mold member.

14. The method of claim 7 , wherein the surfaces of the disk valve on the convex side and the concave side are made substantially flat by shrinkage of the elastic seal member.

15. The method of claim 7 , wherein an inner peripheral portion of the disk valve is clamped, and the surface on the concave side of an outer peripheral portion of the disk valve seats on a seat portion of the piston and opens from the seat portion;
the elastic seal member is slidably fitted into a valve member disposed at a back of the disk valve to form a back-pressure chamber in the valve member,
wherein a pressure in the back-pressure chamber acts on the disk valve in a direction for closing the disk valve.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Kitagawa Yasuyuki
• Kubo Naoya

Classifications

• Y10T29/49405

  Valve or choke making · CPC title

• F16F9/3484 Primary

  characterised by features of the annular discs per se, singularly or in combination · CPC title

• Y10T29/4998

  Combined manufacture including applying or shaping of fluent material · CPC title

• B29C2045/14893

  Preventing defects relating to shrinkage of inserts or coating material · CPC title

• B29C2045/14459

  injecting seal elements · CPC title