Variable radius spring disc for vehicle shock absorber

Patent metadata

Field	Value
Publication number	US-9587703-B2
Application number	US-201514716048-A
Country	US
Kind code	B2
Filing date	May 19, 2015
Priority date	May 20, 2014
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A shock absorber for a vehicle may include a piston and a valve disc assembly. The piston defines a plurality of passages extending through the piston between an upper working chamber and a lower working chamber of a fluid chamber. The valve disc assembly engages the piston and controls a flow of fluid between the upper working chamber and the lower working chamber through the plurality of passages. The valve disc assembly includes a variable radius spring disc among a plurality of discs. The variable radius spring disc has a varying outer radius. The valve disc assembly has a stiffness that varies circumferentially based on the variable radius spring disc such that an actuation of the valve disc assembly with respect to the piston varies circumferentially.

First claim

What is claimed is:

1. A shock absorber for a vehicle comprising:
a pressure tube defining a fluid chamber;
a piston disposed within the fluid chamber, the piston dividing the fluid chamber into an upper working chamber and a lower working chamber, the piston defining a plurality of passages extending through the piston between the upper working chamber and the lower working chamber; and
a valve disc assembly supported on the piston and controlling a flow of fluid between the upper working chamber and the lower working chamber through the plurality of passages, the valve disc assembly including a variable radius spring disc among a plurality of discs, wherein
the variable radius spring disc has an outer radius that increases continuously and circumferentially from a first circumferential point to a second circumferential point, along an outer perimeter of the variable radius spring disc, and then makes a convex turn followed by a transition from the second circumferential point via a concave turn back to the first circumferential point, and
the valve disc assembly creates a stiffness that varies in relation to a circumference of the variable radius spring disc such that an actuation of the valve disc assembly with respect to the piston varies circumferentially.

2. The shock absorber of claim 1 wherein the variable radius spring disc has an asymmetrical shape.

3. The shock absorber of claim 1 wherein the variable radius spring disc has a maximum outer radius and a minimum outer radius, and a given outer radius measured from a center point to a given point along the outer perimeter has a value between the maximum outer radius and the minimum outer radius.

4. The shock absorber of claim 1 wherein:
the plurality of discs of the valve disc assembly further includes an orifice disc and one or more solid discs, and
the plurality of discs are arranged such that at least one of the one or more solid discs is disposed between the orifice disc and the variable radius spring disc.

5. The shock absorber of claim 1 wherein:
the plurality of discs actuate away from the piston along a first direction to allow fluid flow between the upper working chamber and the lower working chamber, and actuate toward the piston along a second direction opposite to the first direction to prevent fluid flow between the upper working chamber and the lower working chamber,
the first direction corresponds to a direction along which the outer radius of the variable radius spring disc increases, and
the second direction corresponds to a direction along which the outer radius of the variable radius spring disc decreases.

6. The shock absorber of claim 1 wherein:
the piston includes a support land that circumferentially extends along a surface of the piston, and
the plurality of discs of the valve disc assembly further includes an orifice disc and one or more solid discs, the plurality of discs is disposed at the support land and is arranged such that the orifice disc is disposed on the support land and at least one of the one or more solid discs is disposed between the orifice disc and the variable radius spring.

7. The shock absorber of claim 1 wherein:
the variable radius spring disc has a maximum outer radius and a minimum outer radius, and
fluid pressure required to deflect the valve disc assembly from the piston is greater at a portion of the valve disc assembly that aligns with the minimum outer radius than a portion of the valve disc assembly that aligns with the maximum outer radius.

8. The shock absorber of claim 1 wherein the stiffness of the valve disc assembly increases as the outer radius of the variable spring disc increases.

9. The shock absorber of claim 1 wherein:
the valve disc assembly deflects away from the piston along a direction that corresponds to an increase in the outer radius of the variable radius spring disc as fluid pressure increases in the plurality of passages, and
the valve disc assembly actuates to seal the plurality of passages along a direction that corresponds to a decrease in the outer radius of the variable radius spring disc as fluid pressure decreases in the plurality of passages.

10. A shock absorber for a vehicle comprising:
a pressure tube defining a fluid chamber;
a piston disposed within the fluid chamber, the piston dividing the fluid chamber into an upper working chamber and a lower working chamber, the piston defining a plurality of passages extending through the piston between the upper working chamber and the lower working chamber; and
a valve disc assembly engaging the piston and controlling a flow of fluid between the upper working chamber and the lower working chamber through the plurality of passages, the valve disc assembly including a plurality of discs, wherein the plurality of discs includes a helical disc, wherein
the helical disc has an outer radius that increases continuously and circumferentially from a first point to a second point, along an outer perimeter of the helical disc, and then makes a convex turn followed by a transition from the second point via a concave turn back to the first point, and
the valve disc assembly has a stiffness that circumferentially varies based on the outer radius of the helical disc such that the valve disc assembly circumferentially actuates in a wraparound manner along the piston.

11. The shock absorber of claim 10 wherein the stiffness of the valve disc assembly is proportional to a surface area of the helical disc such that the stiffness increases as the surface area of the helical disc increases.

12. The shock absorber of claim 10 wherein the stiffness of the valve disc assembly increases as the outer radius of the helical disc increases and decreases as the outer radius of the helical disc decreases.

13. The shock absorber of claim 10 further comprising:
a reservoir tube; and
a base valve assembly, wherein
the pressure tube is housed in the reservoir tube,
the pressure tube and the reservoir tube define a reservoir chamber,
the base valve assembly controls the flow of fluid between the lower working chamber and the reservoir chamber, and
the base valve assembly includes a second helical disc among a second plurality of discs, the second helical disc has an outer radius that varies circumferentially along an outer perimeter of the second helical disc.

14. The shock absorber of claim 10 wherein:
the plurality of discs of the valve disc assembly further includes an orifice disc and one or more solid discs, and
the plurality of discs are arranged such that at least one of the one or more solid discs is disposed between the orifice disc and the helical disc.

15. The shock absorber of claim 10 wherein:
the plurality of discs actuate away from the piston along a first direction to allow fluid flow between the upper working chamber and the lower working chamber, and actuate toward the piston along a second direction opposite to the first direction to prevent fluid flow between the upper working chamber and the lower working chamber,
the first direction corresponds to a direction along which the outer radius of the helical disc increases, and
the second direction corresponds to a direction along which the outer radius of the helical disc decreases.

16. The shock absorber of claim 10 wherein the helical disc has a maximum outer radius and a minimum outer radius, and fluid pressure required to deflect the valve disc assembly at the maximum outer radius of the helical disc is greater than at the minimum outer radius of the helical disc.

17. A shock absorber for a vehicle

Assignees

• Tenneco Automotive Operating Co Inc

Inventors

• Rummel Chad

Classifications

• B60G13/08

  hydraulic · CPC title

• B60G2500/114

  pressure regulating valves · CPC title

• F16F9/3484 Primary

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

• F16F9/34

  Special valve constructions ({F16F9/44, F16F9/50 take precedence; filtering details F16F9/3285} ; valves in general F16K); Shape or construction of throttling passages · CPC title

• F16F9/3488

  characterised by features intended to affect valve bias or pre-stress · CPC title