SHOCK ABSORBER WITH A HYDROSTOPPER

• US 20200132156A1
• Filed: 09/10/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: MORINAGA, Hirofumi, MOGI, Asuka
• Granted Patent: US 11,339,848 B2
• Time in Patent Office: Days
• CPC Class Codes: F16F 15/023 using fluid means
• CPC Class Codes: F16F 2222/12 Fluid damping
• CPC Class Codes: F16F 2228/066 Variable stiffness
• CPC Class Codes: F16F 2230/007 with, or used as an end stop or buffer; Limiting excessive axial separation
• CPC Class Codes: F16F 9/18 with a closed cylinder and a piston separating two or more working spaces therein
• 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 9/49 Stops limiting fluid passage, e.g. hydraulic stops or elastomeric elements inside the cylinder which contribute to changes in fluid damping fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22
• CPC Class Codes: F16F 9/585 within the cylinder, in contact with working fluid

Abstract

A shock absorber with a hydrostopper is provided. The hydrostopper includes a stopper piston that is relatively displaceable along a rod portion of a piston and partitions one cylinder chamber into an upper chamber and a lower chamber, and a compression coil spring that biases the stopper piston against a stopper disc fixed to the rod portion in the lower chamber. The stopper piston has an orifice passage connecting the upper and lower chambers. The hydrostopper includes an elastic disk functioning as an elastically deformable member that increases an amount of elastic deformation to increase an amount of reduction of an effective passage cross-sectional area of the orifice passage as a differential pressure between pressures in the upper and lower chambers is larger when the pressure in the upper chamber is higher than the pressure in the lower chamber.

Claims

1. A shock absorber with a hydrostopper comprising:

a cylinder, a piston fitted to the cylinder and cooperating with the cylinder to form first and second cylinder chambers of variable volume, the first cylinder chamber receiving a rod portion of the piston, and a hydrostopper that is configured to limit relative displacement of the piston in an extension direction relative to the cylinder;

the hydrostopper comprising a stopper piston that is fitted to the rod portion so as to be relatively displaceable along the rod portion and divides the first cylinder chamber into first and second stopper chambers, an engagement member fixed to the rod portion in the second stopper chamber located on the side of the second cylinder chamber relative to the stopper piston, and a biasing member for biasing the stopper piston against the engagement member, and the stopper piston having an orifice passage connecting the first and second stopper chambers, wherein

the hydrostopper includes an elastically deformable member configured to reduce an effective passage cross-sectional area of the orifice passage by elastic deformation, and the elastically deformable member is configured to increase a reduction amount of the effective passage cross-sectional area as a differential pressure between pressures in the first and second stopper chambers is larger when the pressure in the first stopper chamber is higher than the pressure in the second stopper chamber.

2. The shock absorber with a hydrostopper according to claim 1, wherein the elastically deformable member is configured to cooperate with the stopper piston to form a part of the orifice passage, and reduce a cross-sectional area of the part by elastic deformation, thereby reducing the effective passage cross-sectional area of the orifice passage.

3. The shock absorber with a hydrostopper according to claim 2, wherein the elastically deformable member is formed of a rubber-like elastic material, and is configured to be compressively deformed by being compressed between the stopper piston and the engagement member and enter the part, thereby reducing the cross-sectional area of the part.

4. The shock absorber with a hydrostopper according to claim 2, wherein the elastically deformable member is formed of a rubber-like elastic material, and is configured to be compressively deformed by being pressed against the stopper piston by a differential pressure between pressures in the first and second stopper chambers and reduce the sectional area of the part by changing a cross-sectional shape of the part.

5. The shock absorber with a hydrostopper according to claim 2, wherein the elastically deformable member is a bent deformable valve member that forms the part in cooperation with a valve seat provided on the stopper piston, and the valve member is configured to cooperate with the valve seat to reduce the cross-sectional area of the part by being pressed against the valve seat and being bent deformed by a differential pressure between pressures in the first and second stopper chambers.