VEHICLE SUSPENSION SYSTEM

• US 20080018028A1
• Filed: 07/18/2007
• Published: 01/24/2008
• Est. Priority Date: 07/20/2006
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Kamioka, Takamasa
• Granted Patent: US 8,689,954 B2
• Time in Patent Office: Days
• US Class Current: 267/64.23
• CPC Class Codes: B60G 11/27 wherein the fluid is a gas
• CPC Class Codes: B60G 15/12 and fluid damper
• CPC Class Codes: B60G 17/044 Self-pumping fluid springs pumps for liquids F04
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2300/12 Cycles; Motorcycles
• CPC Class Codes: B62K 25/283 for cycles without a pedal crank, e.g. motorcycles
• CPC Class Codes: F16F 9/0209 Telescopic F16F9/04 takes precedence
• CPC Class Codes: F16F 9/435 via opening in cylinder wall F16F9/432 takes precedence

Abstract

A vehicle suspension system that inhibits a pressure within a gas chamber from reducing below a threshold value. In one arrangement, the suspension system includes a shock absorber associated with a motorcycle. The shock absorber includes an upper gas chamber that is filled with air. An air pressure adjustment valve operates to supply air into the upper gas chamber from a supply of air outside of the shock absorber when the air pressure in the upper gas chamber becomes smaller than a lower threshold value.

Claims

1. A vehicle comprising:

a vehicle body;

a vehicle wheel; and

a shock absorber operably positioned between the vehicle body and the vehicle wheel, wherein the shock absorber comprises an air chamber containing air, and at least a first pressure adjustment valve that introduces air into the air chamber from outside of the shock absorber when the air pressure in the air chamber is below a lower threshold value.

2. The vehicle of claim 1, wherein the first pressure adjustment valve of the shock absorber is arranged such that the air is introduced into the air chamber from outside of the shock absorber as a result of extension and compression movement of the shock absorber.

3. The vehicle of claim 1, wherein the first pressure adjustment valve of the shock absorber comprises a first check valve.

4. The vehicle of claim 1, wherein the lower threshold value is approximately 1 atmosphere.

5. The vehicle of claim 1, wherein the air chamber comprises a first air chamber that reduces in volume upon extension of the shock absorber and that increases in volume upon compression of the shock absorber, and a second air chamber that increases in volume upon extension of the shock absorber extends and that reduces in volume upon compression of the shock absorber.

6. The vehicle of claim 5, wherein the shock absorber comprises an outer tube member, a shaft member that is moveable within the outer tube member, and at least a first piston that is carried by the shaft member, wherein and the first air chamber is defined by a space that is bounded by at least an inner surface of the outer tube member, an outer surface of the shaft member, and the first piston, and the second air chamber is defined by a space that is bounded by at least the inner surface of the outer tube member and the first piston.

7. The vehicle of claim 6, wherein the shaft member defines an oil chamber filled with oil, and the shock absorber further comprises a second piston disposed within the oil chamber of the shaft member, wherein the second piston moves inside the oil chamber of the shaft member upon extension and compression of the shock absorber to generate a damping force.

8. The vehicle of claim 5, wherein the first air chamber is connected to the outside of the shock absorber by the first pressure adjustment valve.

9. The vehicle of claim 8, wherein air is introduced into the first air chamber from the outside of the shock absorber as a result of the air in the first air chamber expanding upon compression of the shock absorber.

10. The vehicle of claim 8, wherein the shock absorber further comprises a second pressure adjustment valve that supplies air to the second air chamber from the first air chamber, and when the air pressure in the second air chamber becomes less than the air pressure in the first air chamber as a result of expansion of the air in the second air chamber upon extension of the shock absorber, air is supplied from the first air chamber to the second air chamber by the second pressure adjustment valve.

11. The vehicle of claim 10, wherein the second air pressure adjustment valve of the shock absorber comprises a second check valve.

12. The vehicle of claim 5, wherein the shock absorber further comprises a third pressure adjustment valve that discharges air from the first air chamber to the outside of the shock absorber when the air pressure in the first air chamber becomes larger than an upper threshold value as a result of air in the first air chamber being compressed upon extension of the shock absorber.

13. The vehicle of claim 12, wherein the third pressure adjustment valve of the shock absorber comprises a third check valve.

14. The vehicle of claim 12, wherein the third pressure adjustment valve has an adjustment member that adjusts the upper threshold value of the air pressure at which air in the first air chamber is discharged from the first air chamber to the outside of the shock absorber by the third pressure adjustment valve.

15. The vehicle of claim 12, wherein the upper threshold value is approximately 9 atmospheres.

16. The vehicle of claim 1, wherein the shock absorber is a rear wheel suspension.

17. A vehicle comprising:

a vehicle body;

a vehicle wheel; and

a shock absorber operably positioned between the vehicle body and the vehicle wheel, wherein the shock absorber comprises;

a first portion;

a second portion movable relative to the first portion, wherein the first portion and the second portion cooperate to define a first gas chamber and a second gas chamber, wherein the first gas chamber and the second gas chamber vary in volume upon relative movement of the first portion and the second portion of the shock absorber to provide a suspension spring force;

at least a first pressure adjustment valve that introduces a gas into the first gas chamber from a supply of gas other than the second gas chamber when the pressure in the first gas chamber is below a lower threshold value.

18. The vehicle of claim 17, further comprising a second pressure adjustment valve that supplies air to the second gas chamber from the first gas chamber when the pressure in the second gas chamber becomes less than the pressure in the first gas chamber.

19. The vehicle of claim 17, wherein the shock absorber further comprises a third pressure adjustment valve that discharges air from the first gas chamber when the pressure in the first gas chamber becomes larger than an upper threshold value.

20. A vehicle comprising:

a vehicle body;

a vehicle wheel; and

a shock absorber operably positioned between the vehicle body and the vehicle wheel, wherein the shock absorber comprises an air chamber containing air, and at least a first pressure adjustment means for introducing air into the air chamber from outside of the shock absorber when the air pressure in the air chamber is below a lower threshold value.