Pressure controlled suspension damper

• US 20020108827A1
• Filed: 02/09/2001
• Published: 08/15/2002
• Est. Priority Date: 02/09/2001
• Status: Active Grant

• Current Assignee: BWI Company Limited SA (Shougang Corporation)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Miller, Troy A., Kruckemeyer, William C., Oliver, Michael L.
• Granted Patent: US 6,527,093 B2
• Time in Patent Office: Days
• US Class Current: 188/313
• CPC Class Codes: F16F 2230/183 fluid actuated
• CPC Class Codes: F16F 9/464 Control of valve bias or pre-stress, e.g. electromagnetically F16F9/465 takes precedence

Abstract

A vibration damper for a vehicle suspension system includes a pumping cylinder concentrically aligned inside a housing defining a pumping chamber having a piston stroking therein for reducing the level of vehicle vibration. An intermediate cylinder defines an intermediate chamber with the pumping cylinder and an outer chamber with the housing. Suspension fluid flows throughout each of the chambers. A valve is operably connected to an air supply of a suspension system having an air pressure relative to a mass loaded on the vehicle. The controls the distribution of fluid between the chambers relative to the pressure of the air supply and controls the amount of vibration damping inside the pumping chamber relative to the mass loaded on the vehicle.

Claims

1. A suspension damper assembly for a vehicle suspension system comprising:

a housing;

a pumping cylinder axially aligned inside said housing defining a pumping chamber having a piston stroking therein;

an intermediate cylinder defining an intermediate chamber with said pumping cylinder and an outer chamber with said housing;

suspension fluid disposed throughout each of said chambers;

a valve controlling the distribution of fluid between said chambers thereby controlling the amount of vibration damping inside said pumping chamber, said valve comprising;

a spring actuated member biased to restrict the flow of fluid between said outer chamber and said intermediate chamber;

an air chamber coupled to a source of pressurized air; and

a bellows disposed inside said air chamber exerting counter-force upon said spring relative to the air pressure inside said air chamber thereby increasing the amount of fluid flowing between said outer chamber and said intermediate chamber.

2. An assembly as set forth in claim 1 wherein said air source comprises air from an air suspension system.

3. An assembly as set forth in claim 2 wherein said assembly includes a casing forming a fluid return passage around said housing connecting said spring actuated member to said outer chamber.

4. An assembly as set forth in claim 3 wherein said valve includes a valve cap assembly having at least one aperture allowing fluid to flow between said intermediate chamber and said spring actuated member.

5. An assembly as set forth in claim 4 wherein said cap assembly includes a one way valve moveable to allow fluid to flow into said spring actuated member from said intermediate chamber.

6. An assembly as set forth in claim 5 wherein said housing includes at least one housing aperture allowing fluid to flow between said spring actuated member and said return passage.

7. An assembly as set forth in claim 6 wherein said spring actuated member includes a sleeve having a plurality of sleeve apertures communicating with said at least one housing aperture and a spool slideably disposed within said sleeve.

8. An assembly as set forth in claim 7 wherein said spool receives said spring, said spring biasing said spool to close said sleeve apertures thereby restricting the flow of fluid from said intermediate chamber to said outer chamber.

9. An assembly as set forth in claim 8 wherein said valve includes a seal plate sealing said spring actuated member from said air chamber.

10. An assembly as set forth in claim 9 wherein said bellows includes a pin slideably inserted through said seal plate and abutting said spool for providing a counter bias upon said spool from said spring.

11. An assembly as set forth in claim 1 wherein said bellows contracts as pressure increases in said air chamber thereby reducing the amount of counter bias upon said spool.

12. An assembly as set forth in claim 11 wherein said bellows expands as pressure decreases thereby increasing the amount of counter bias upon said spool.

13. An assembly as set forth in claim 11 wherein the pressure in said air chamber is proportional to the mass of the vehicle.

15. An assembly as set forth in claim 14 wherein said valve includes a spring actuated member biased to restrict the flow of fluid between said outer chamber and said inner chamber.

16. An assembly as set forth in claim 15 wherein said valve includes an air chamber operably connected to said air supply.

17. An assembly as set forth in claim 16 wherein said valve includes a bellows disposed inside said air chamber exerting counter biasing force upon said spring actuated member relative to the air pressure inside said air chamber thereby increasing the amount of fluid flowing between said outer chamber and said intermediate chamber.

18. An assembly as set forth in claim 17 wherein said assembly includes a casing forming a fluid return passage around said housing connecting said spring actuated member to said outer chamber.

19. An assembly as set forth in claim 18 wherein said valve includes a valve cap assembly having at least one aperture allowing fluid to flow between said intermediate chamber and said spring actuated member.

20. An assembly as set forth in claim 19 wherein said cap assembly includes an one way valve moveable to allow fluid to flow into said spring actuated member from said intermediate chamber.

21. An assembly as set forth in claim 20 wherein said housing includes at least one housing aperture allowing fluid to flow between said spring actuated member and said return passage.

22. An assembly as set forth in claim 21 wherein said spring actuated member includes a sleeve having a plurality of sleeve apertures communicating with said at least one housing aperture and a spool slideably disposed within said sleeve.

23. An assembly as set forth in claim 22 wherein said spool receives said spring, said spring biasing said spool to close said sleeve apertures thereby restricting the flow of fluid from said intermediate chamber to said outer chamber.

24. An assembly as set forth in claim 23 wherein said valve includes a seal plate sealing said spring actuated member from said air chamber.

25. An assembly as set forth in claim 24 wherein said bellows includes a pin slideably inserted through said seal plate and abutting said spool for providing a counter bias upon said spool from said spring.

26. An assembly as set forth in claim 14 wherein said bellows contracts as pressure increases in said air chamber thereby reducing the amount of counter bias upon said spool.

27. An assembly as set forth in claim 26 wherein said bellows expands as pressure decreases thereby increasing the amount of counter bias upon said spool.

29. A method as set forth in claim 28 wherein in said step of controlling the amount of fluid disposed within the pumping chamber is further defined by directing fluid from an intermediate chamber to the pumping chamber.

30. A method as set forth in claim 29 wherein said step of wherein in the step of controlling the amount of fluid disposed within the pumping chamber is further defined by directing fluid from the intermediate chamber through the valve to an outer chamber.

31. A method as set forth in claim 30 wherein said step of wherein in the step of controlling the amount of fluid disposed within the pumping chamber is further defined by directing fluid from the pumping chamber to the outer chamber.

14. A suspension damper assembly for a vehicle suspension system having an air supply with an air pressure being relative to a mass loaded on the vehicle comprising:

a housing;

a pumping cylinder concentrically aligned inside said housing defining a pumping chamber having a piston stroking therein for reducing the level of vehicle vibration;

an intermediate cylinder defining an intermediate chamber with said pumping cylinder and an outer chamber with said housing;

suspension fluid disposed throughout each of said chambers;

a valve operably connected to said air supply of said suspension system thereby controlling the distribution of fluid between said chambers relative to the pressure of the air supply and controlling the amount of vibration damping inside said pumping chamber relative to the mass loaded on the vehicle.

28. A method of damping road vibration for a vehicle capable of carrying a load comprising the steps of:

providing a suspension damper assembly for an air suspension system and having a piston stroking inside a pumping chamber with fluid disposed therein;

providing a valve operably connected to said suspension damper for controlling the amount of fluid disposed within the pumping chamber;

actuating the valve with air pressure derived from the air suspension system relative to the load carried by the vehicle.