SHOCK ABSORBER

• US 20180216690A1
• Filed: 09/14/2016
• Published: 08/02/2018
• Est. Priority Date: 09/14/2015
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: YAMASHITA, Mikio
• Granted Patent: US 10,619,694 B2
• Time in Patent Office: Days
• CPC Class Codes: B60G 13/08 hydraulic
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: B60G 2204/128 Damper mount on vehicle body or chassis
• CPC Class Codes: B60G 2204/129 Damper mount on wheel suspension or knuckle
• CPC Class Codes: B60G 2206/41 Dampers
• CPC Class Codes: B60G 2500/11 Damping valves
• CPC Class Codes: B60G 2600/182 Active control means
• CPC Class Codes: B60G 2600/21 Self-controlled or adjusted
• CPC Class Codes: B60G 2800/162 Reducing road induced vibrations
• CPC Class Codes: F16F 2228/066 Variable stiffness
• CPC Class Codes: F16F 2230/00 Purpose; Design features
• CPC Class Codes: F16F 9/062 Bi-tubular units
• CPC Class Codes: F16F 9/185 Bitubular units where compression of gas leads to a clear spring action F16F9/062
• CPC Class Codes: F16F 9/19 with a single cylinder and of single-tube type
• CPC Class Codes: F16F 9/348 Throttling passages in the form of annular discs or other plate-like elements which may or may not have a spring action, operating in opposite directions or singly, e.g. annular discs positioned on top of the valve or piston body F16F9/341, F16F9/3415 take precedence
• CPC Class Codes: F16F 9/512 Means responsive to load action, i.e. static load on the damper or dynamic fluid pressure changes in the damper, e.g. due to changes in velocity F16F9/504, F16F9/516 take precedence; non-automatic damper adjustment from a distance using servo control, the servo pressure being created by the flow of damping fluid F16F9/465; self-pumping fluid springs in vehicle suspensions B60G17/044

Abstract

A shock absorber including: a first passage (101) allowing working fluid to flow out from one chamber (19) as a result of movement of a piston (18); a second passage (181) provided in parallel with the first passage; a damping force generating mechanism (41) provided in the first passage, and configured to generate a damping force; a tubular case member (140) including at least a part of the second passage formed therein; an annular disc (134) supported on an inner peripheral side or an outer peripheral side in the case member. An annular seal member (156) configured to seal a gap to the case member is provided on a non-supported side of the annular disc. The shock absorber further includes two chambers (171, 172) in the case member, which are defined and provided by the disc. The disc is configured to block flow to the second passage.

Claims

1-10. -10. (canceled)

11. A shock absorber comprising:

a cylinder sealingly enclosing working fluid;

a piston slidably fitted in the cylinder and partitioning an inside of the cylinder into two chambers;

a piston rod including one end side coupled to the piston and an opposite end side extending to an outside of the cylinder;

a first passage allowing the working fluid to flow out from one of the chambers in the cylinder as a result of movement of the piston;

a second passage provided in parallel with the first passage;

a damping force generating mechanism provided in the first passage, and configured to generate a damping force;

a tubular case member including at least a part of the second passage formed therein;

a shaft part disposed in the case member;

a flexible annular disc disposed in the case member while being passed through by the shaft part, and supported on an inner peripheral side or an outer peripheral side, an annular elastic seal member configured to seal a gap between the flexible annular disc and the case member or a gap between the flexible annular disc and the shaft part on a non-supported side being provided; and

two chambers in the case member which are defined and provided by the disc,

wherein the disc is configured to block flow to at least one side of the second passage,

wherein an annular gap is provided between the disc and the case member or the shaft part, and

wherein the elastic seal member is provided by being fixed to both surfaces of the disc via the gap.

13. The shock absorber according to claim 11, wherein the shaft part is the one end side of the piston rod.

14. The shock absorber according to claim 11,

wherein the cylinder includes a reservoir chamber configured to compensate entry and exit of the piston rod, and

wherein the first passage and the second passage are provided between one of the chambers in the cylinder and the reservoir chamber.

16. The shock absorber according to claim 14, wherein a seal position of the seal member is provided on an upstream side of the disc during the flow to the one side.

17. The shock absorber according to claim 11, wherein the inner peripheral side of the disc is not clamped from both surface sides, and is supported only on one surface side.

18. The shock absorber according to claim 11,

wherein the damping force generating mechanism includes:

a main valve configured to suppress flow of the working fluid generated by a slide of the piston to generate the damping force; and

a pilot chamber configured to apply a pressure in a closing direction to the main valve, and

wherein the damping force generating mechanism is configured to introduce part of the flow of the working fluid into the pilot chamber to control opening of the main valve through the pressure in the pilot chamber.

12. A shock absorber comprising:

a cylinder sealingly enclosing working fluid;

a piston slidably fitted in the cylinder and partitioning an inside of the cylinder into two chambers;

a piston rod including one end side coupled to the piston and an opposite end side extending to an outside of the cylinder;

a first passage allowing the working fluid to flow out from one of the chambers in the cylinder as a result of movement of the piston;

a second passage provided in parallel with the first passage;

a damping force generating mechanism provided in the first passage, and configured to generate a damping force;

a tubular case member including at least a part of the second passage formed therein;

a shaft part disposed in the case member;

a flexible annular disc disposed in the case member while being passed through by the shaft part, and supported on an inner peripheral side or an outer peripheral side, an annular elastic seal member configured to seal a gap between the flexible annular disc and the case member or a gap between the flexible annular disc and the shaft part on a non-supported side being provided; and

two chambers in the case member which are defined and provided by the disc,

wherein the disc is configured to block flow to at least one side of the second passage, and

wherein the disc is configured to block the flow to one side of the second passage, and permit the flow to an opposite side of the second passage

15. The shock absorber according to claim 12, wherein the flow to the opposite side is permitted via a supported side of the disc.

19. A shock absorber comprising:

a cylinder sealingly enclosing working fluid;

an outer tube provided around the cylinder;

a piston slidably fitted in the cylinder;

a piston rod coupled to the piston, and extending to an outside of the cylinder; and

a damping force generating mechanism configured to control flow of working fluid generated by a slide of the piston in the cylinder to generate a damping force,

wherein a tubular case for containing the damping force generating mechanism is provided in the outer tube;

wherein shock absorber includes in the case;

a housing having a bottomed tubular shape;

a main valve provided so as to close an opening of the housing, and configured to control the flow of the fluid generated by the slide of the piston in the cylinder to generate the damping force;

a pilot chamber formed by the housing and the main valve, and configured to apply an inner pressure in a closing direction to the main valve;

an introduction passage configured to introduce the fluid into the pilot chamber;

a pilot passage configured to cause the pilot chamber and a downstream side of the main valve to communicate with each other; and

a control valve provided in the pilot passage;

wherein a disc is provided in the pilot chamber so as to be movable relative to the housing, the disk forming an housing inner chamber between the disc and a bottom portion of the housing, and

wherein a seal member configured to seal a gap between an outer periphery of the disc and an inner periphery of the housing is integrally provided for the disc.