Ground clearance-regulated, air-suspended axle aggregate, for example for monospace private cars

• US 6,491,307 B1
• Filed: 08/03/1999
• Issued: 12/10/2002
• Est. Priority Date: 07/11/1996
• Status: Expired due to Fees

• Current Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Mueller, Hartwig, Charzinski, Uwe, Ricklefs, Gerald, Scheurer, Friedrich, Horwath, Jochen
• Primary Examiner(s): Culbreth, Eric
• Assistant Examiner(s): LUM VANNUCCI, LEE SIN YEE
• Application Number:
  US09/214,344
• Time in Patent Office: 1,225 Days
• Field of Search: 280/5.506, 280/5.508, 280/6.15, 280/9.153, 280/124.157
• US Class Current: 280/5.508
• CPC Class Codes: B60G 17/015 the regulating means comprising electric or electronic elements B60G17/002, B60G17/005 take precedence
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2204/82 left and right unit on same axle
• CPC Class Codes: B60G 2204/8304 using a fluid
• CPC Class Codes: B60G 2500/30 Height or ground clearance

Abstract

An axle assembly with level control, in particular with a pneumatic suspension. Changes in level which may, if appropriate, become necessary on both vehicle sides take place incrementally and with continuous alternation between the vehicle sides, i.e. the left-hand and right-hand vehicle sides are alternately raised or lowered.

Claims

1. Axle assembly with a level control for a pneumatic suspension for a vehicle, comprising:

controllable pneumatic-suspension assemblies which are arranged separately on each vehicle side, the controllable pneumatic-suspension assemblies being connectable separately to at least one of a compressor and an outlet to atmosphere via a control valve arrangement, and

sensors arranged separately for each said vehicle side for sensing at least one of a level of a vehicle body and a distance between a vehicle body part and a wheel carrier of the axle assembly,

wherein a change on both of said sides in the level of the vehicle body takes place incrementally and with continuous alternation between the vehicle sides via a closed-loop or an open-loop control unit which controls the control valve arrangement to directly connect the pneumatic-suspension assembly of the one vehicle side and the pneumatic-suspension assembly of the other vehicle side to the compressor in an alternating fashion to provide successive incremental lifting movements for each of the vehicle sides in an alternating fashion, and when the level of the vehicle body is to be lowered on both of said each sides, said closed-loop or open loop control unit connects the pneumatic-suspension assemblies to the atmosphere in an alternating fashion to carry out successive incremental lowering movements for each of the vehicle sides in an alternating fashion, and

wherein during the respective lifting or lowering movement of a respectively active pneumatic-suspension assembly by the control unit, the level of the vehicle body at the respective vehicle side is set to be higher or lower by a specific amount than the level of the vehicle body at a corresponding pneumatic-suspension assembly on the respective other vehicle side.

2. Axle assembly according to claim 1, wherein the control unit switches on the compressor only when there is an opened connection to one of the pneumatic-suspension assemblies.

3. Axle assembly according to claim 1, wherein the wheel carriers which are assigned to the two vehicle sides are connected to one another via a rigid axle or a coupling which is similar to a rigid axle.

4. Axle assembly according to claim 1, wherein the pneumatic-suspension assemblies are arranged at a predetermined distance from the wheel carriers in the transverse direction of the vehicle.

5. Axle assembly according to claim 1, further comprising a stabilizer which is arranged on the axle assembly.

6. Axle assembly according to claim 1, wherein command value or setpoint value signal transmitters which can be activated manually are assigned to the control unit.

7. Axle assembly according to claim 1, wherein, when the level of the vehicle body is raised when the vehicle is stationary, at least the pneumatic-suspension assembly which was last to be fed compressed air is briefly connected to the atmosphere when a desired level is reached.

8. Axle assembly according to claim 1, wherein, when the level of the vehicle body is lowered when the vehicle is stationary, the respective pneumatic-suspension assembly is connected to the atmosphere only in a pulsed fashion by alternately opening and closing a shut-off valve just before a desired level is reached.

9. Axle assembly according to claim 1, wherein when the vehicle is travelling a timed raising or lowering of the level takes place in that a pneumatic-suspension assembly is vented or ventilated for a predetermined time period and it is then checked whether the respectively reached level lies within a tolerance band, and wherein further timed corrections then take place if appropriate.

10. Axle assembly according to claim 1, wherein when the vehicle is starting to travel, a rapid change in level takes place if the difference from the desired level is large and differences in level are present in the same direction on both sides of the vehicle.

11. A method of adjusting a level of a vehicle having separately controllable left-side and right-side pneumatic-suspension assemblies and corresponding left-side and right-side vehicle level sensors, said method comprising:

sensing an actual level of the vehicle via said level sensors;

comparing the actual level of the vehicle with a desired vehicle level; and

adjusting said left-side and right-side pneumatic-suspension assemblies by continuously alternating between the following steps until the actual level of the vehicle corresponds to said desired vehicle level;

(a) adjusting one of said left-side and right-side pneumatic-suspension assemblies until a difference in the level between the left-side pneumatic-suspension assembly and the right-side pneumatic-suspension assembly is a predetermined value, and

(b) adjusting the other of said left-side and right-side pneumatic-suspension assemblies until a difference in the level between the left-side pneumatic-suspension assembly and the right-side pneumatic-suspension assembly is said predetermined value.

12. Axle assembly with a level control for a pneumatic suspension for a vehicle, comprising:

controllable left-side and right-side pneumatic-suspension assemblies which are arranged separately on each vehicle side in relation to a longitudinal axis of the vehicle, the controllable pneumatic-suspension assemblies being connectable separately to at least one of a compressor and an outlet to atmosphere via a control valve arrangement, and

sensors arranged separately on each said vehicle side for sensing at least one of a level of a vehicle body and a distance between a vehicle body part and a wheel carrier of the axle assembly,

wherein a change on both of said sides in the level of the vehicle body takes place incrementally and with continuous alternation between the vehicle sides via a closed-loop or an open-loop control unit which controls the control valve arrangement to directly connect the left-side pneumatic-suspension assembly and the right-side pneumatic-suspension assembly to the compressor in an alternating fashion to provide successive incremental lifting movements for each of the vehicle sides in an alternating fashion, and when the level of the vehicle body is to be lowered on both of said each sides, said closed-loop or open loop control unit connects the left-side and the right-side pneumatic-suspension assemblies to the atmosphere in an alternating fashion to carry out successive incremental lowering movements for each of the vehicle sides in an alternating fashion and,

wherein during the respective lifting or lowering movement of a respectively active pneumatic-suspension assembly by the control unit, the level of the vehicle body at the respective vehicle side is set to be higher or lower by a specific amount than the level of the vehicle body at a corresponding pneumatic-suspension assembly on the respective other vehicle side.

13. An assembly for adjusting a level of a vehicle having separately controllable left-side and right-side pneumatic-suspension assemblies and corresponding left-side and right-side vehicle level sensors comprising:

means for sensing an actual level of the vehicle via said level sensors,

means for comparing the actual level of the vehicle with a desired vehicle level, and

means for adjusting said left-side and right-side pneumatic-suspension assemblies by continuously alternating between the following steps until the actual level of the vehicle corresponds to said desired vehicle level;

(a) adjusting one of said left-side and rightside pneumatic-suspension assemblies until a difference in the level between the left-side pneumatic-suspension assembly and the right-side pneumatic-suspension assembly is a predetermined value, and

(b) adjusting the other of said left-side and right-side pneumatic-suspension assemblies until a difference in the level between the left-side pneumatic-suspension assembly and the right-side pneumatic-suspension assembly is said predetermined value.