Pneumatic-spring wheel-suspension leg

• US 20030127781A1
• Filed: 01/08/2003
• Published: 07/10/2003
• Est. Priority Date: 01/10/2002
• Status: Active Grant

• Current Assignee: Thyssenkrupp Bilstein Gmbh (Thyssenkrupp AG)
• Original Assignee: Thyssenkrupp Bilstein Gmbh (Thyssenkrupp AG)
• Inventors: Fritz, Michael
• Granted Patent: US 6,910,682 B2
• Time in Patent Office: Days
• US Class Current: 267/64.24
• CPC Class Codes: B60G 15/12 and fluid damper
• CPC Class Codes: B60G 2202/314 The spring being a pneumatic spring
• CPC Class Codes: B60G 2204/1262 on a damper
• CPC Class Codes: B60G 2500/2041 for variable volume air springs, e.g. using accumulators as expansion chambers
• CPC Class Codes: B60G 2500/22 Spring constant
• CPC Class Codes: F16F 9/05 the flexible wall being of the rolling diaphragm type

Abstract

A pneumatic-spring wheel-suspension leg for motor vehicles. The leg comprises a bellows (1) that can be rolled up over a jacket (3) and accommodates a pneumatics chamber (9), a hydraulic dashpot inside the bellows or jacket, and a piston rod (5) that travels into and out of the dashpot and is attached axially and resiliently directly or indirectly at one end to the vehicle'"'"'s chassis. The object is to relieve the dashpot of difficult attenuation tasks when a hard wheel suspension is necessary. The leg accordingly includes another pneumatics chamber (10) and the communication between the two pneumatics chambers can be partly or entirely blocked by a valve.

Claims

1. Pneumatic-spring wheel-suspension leg for motor vehicles comprising a bellows (1) that can be rolled up over a jacket (3) and accommodates a pneumatics chamber (9), a hydraulic dashpot inside the bellows or jacket, and a piston rod (5) that travels into and out of the dashpot and is attached axially and resiliently directly or indirectly at one end to the vehicle'"'"'s chassis, characterized in that the leg includes another pneumatics chamber (10) and in that the communication between the two pneumatics chambers can be partly or entirely blocked by a valve.

2. Pneumatic-spring leg as in claim 1, characterized in that the valve can close more or less extensively independently of how forcefully the piston rod (5) is resting against the vehicle'"'"'s chassis.

3. Pneumatic-spring leg as in claim 2, characterized in that the valve will remain entirely open as long as the piston rod (5) is not exerting any force against the chassis.

4. Pneumatic-spring leg as in claim 2, characterized in that the valve will remain closed as long as the piston rod (5), traveling in either direction, is exerting a prescribed force against the chassis.

5. Pneumatic-spring leg as in one or more of claims 1 through 4, characterized in that the valve is controlled in accordance with the relative motion between the piston rod (5) and the chassis.

6. Pneumatic-spring leg as in one or more of claims 1 through 5, characterized in that one pneumatics chamber (9) is essentially positioned below the end of the piston rod (5) and the other pneumatics chamber (10) essentially above the end of the piston rod.

7. Pneumatic-spring leg as in one or more of claims 1 through 6, characterized in that the volume of fluid in one pneumatics chamber (10) remains constant.

8. Pneumatic-spring leg as in one or more of claims 1 through 7, characterized in that the valve includes a gasket (13) with edges (14, 15, &

16) on each side that create a seal in conjunction with elevated contact surfaces (19 &

20) located at specific distances therefrom.

9. Pneumatic-spring leg as in claim 8, characterized in that the gasket (13) is fastened to a component of the vehicle'"'"'s chassis or to the piston rod (5) and the contact surfaces (19 &

20) are fastened to the piston rod or to a component of the vehicle'"'"'s chassis.

10. Pneumatic-spring leg as in one of claims 8 and 9, characterized in that the seal-creating edges (14, 15, &

16) are resilient, preferably rubber or plastic, lips.

11. Pneumatic-spring leg as in one or more of claims 1 through 10, characterized in that the seal-creating edges (14, 15, &

16) also act as mechanical compression or tension limiters.

12. Pneumatic-spring leg as in one or more of claims 1 through 11, characterized in that the decrease in the distance (18) between one seal-creating edge (16) and its associated contact surface (20) is assisted by the compression-limiter buffer (21) as the dashpot comes to rest against the latter.