Suspension system

• US 7,753,385 B2
• Filed: 10/03/2007
• Issued: 07/13/2010
• Est. Priority Date: 10/14/2006
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Bitter, Marcus
• Primary Examiner(s): Dickson; Paul N.
• Assistant Examiner(s): Wilhelm; Timothy
• Application Number:
  US11/866,757
• Publication Number:
  US 20080088107A1
• Time in Patent Office: 1,014 Days
• Field of Search: 280/124.161, 280/124.16, 280/124.159, 280/124.106, 267/64.11
• US Class Current: 280/124.161
• CPC Class Codes: B60G 17/005 Suspension locking arrangements for retractable wheels B62D61/12
• CPC Class Codes: B60G 17/056 Regulating distributors or valves for hydropneumatic systemsB60G17/044 - B60G17/048, B60G17/0416 take precedence; Fluid interconnection systems to control vehicle inclination B60G21/06, B60G21/10; valves per se F16K
• CPC Class Codes: B60G 21/073 between wheels on the same axle but on different sides of the vehicle, i.e. the left and right wheel suspensions being interconnected
• CPC Class Codes: B60G 2300/083 Boom carrying vehicles, e.g. for crop spraying
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2500/02 Supply or exhaust flow rates; Pump operation
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control

Abstract

A suspension system for an agricultural or construction industry vehicle is described. The suspension system comprises two hydraulic cylinders which support a frame in relation to an axle of the vehicle, the hydraulic cylinders being hydraulically connected to one another in a cross connection, so that a piston-side chamber of the one hydraulic cylinder is connected to the piston rod-side chamber of the other hydraulic cylinder and vice versa, in each case one hydraulic accumulator assigned to a hydraulic cylinder, a hydraulic source, a hydraulic tank, a control valve device, an electronic control unit, electrically switchable switch valves which are arranged in the cross connection between the hydraulic accumulators and the hydraulic cylinders, and a first and second supply line, which supply lines connect the control vale device to the cross connection. In order to prevent the activation of a suspension state in critical vehicle states, means for the detection and compensation of load states of the vehicle are provided in the suspension system.

Claims

1. A suspension system for an agricultural or construction industry vehicle having a first and a second hydraulic cylinder, which support a frame of the vehicle in relation to an axle of the vehicle, the hydraulic cylinders each having a piston-side chamber and a piston rod-side chamber and the hydraulic cylinders being hydraulically connected to one another in a cross connection via a first connecting line and a second connecting line, so that the piston-side chamber of the first hydraulic cylinder is connected to the piston rod-side chamber of the second hydraulic cylinder and vice versa, having a first hydraulic accumulator arranged in the first connecting line and having a second hydraulic accumulator arranged in the second connecting line, having a hydraulic source, having a hydraulic tank, having a control valve device, having an electronic control unit, having electrically switchable switch valves which are arranged in the first and second connecting lines between the hydraulic accumulators and the chambers of the hydraulic cylinders, and a first and second supply line, which supply lines connect the control valve device to the connecting lines, with the one supply line opening out into the one connecting line between the switch valves of the one connecting line, and the other supply line opening out into the other connecting line between the switch valves of the other connecting line, wherein a means for detection and compensation of load states of the vehicle are provided in the suspension system.

2. A suspension system according to claim 1 wherein the means for the detection and compensation of load states comprise pressure transducers and means for registering the position of a pressure transducer, the pressure transducers in each case being arranged between the piston-side and piston rod-side chambers of each of the hydraulic cylinders.

3. A suspension system according to claim 2 wherein the area ratio of the pressure-generating areas in the chambers of a pressure transducer essentially corresponds to the area ratio of the pressure-generating areas in the chambers of a hydraulic cylinder.

4. A suspension system according to claim 2 wherein the means for registering the position of a pressure transducer comprises one of a switch or sensor.

5. A suspension system according to claim 1 wherein the means for the detection and compensation of load states comprises pressure sensors, which serve to register the pressure in the individual chambers of the first and second hydraulic cylinders.

6. A suspension system according to claim 1 wherein the means for the detection and compensation of load states comprises pressure switches, which are in each case connected to one of the rod-side chambers of the hydraulic cylinders.

7. A suspension system according to claim 1 wherein the means for the detection and compensation of load states comprises force sensors, which serve indirectly or directly to detect forces acting on the hydraulic cylinders.

8. A suspension system according to claim 1 wherein the switch valves have a flow position and a closed position, the closed position comprising a non-return valve opening in the direction of the chamber.

9. A suspension system according to claim 1 wherein the switch valves have a throughflow position and a closed position, which closes in both directions, and are connected in parallel with a non-return valve which opens in the direction of the chamber.

11. A suspension system according to claim 1 wherein the control valve device comprises a first admission line opening into the one supply line and a second admission line opening into the other supply line and a first discharge line opening into the one supply line and a second discharge line opening into the other supply line, the admission lines being connectable via admission control valves to the hydraulic pump or the hydraulic tank and the discharge lines being connectable via discharge control valves to the hydraulic tank.

12. A suspension system according to claim 11 wherein the admission control valves and the discharge control valves comprise switch valves.

13. A suspension system according to claim 11 wherein the admission control valves and the discharge control valves comprise proportional valves.

14. A suspension system according to claim 11 wherein a load-sensing device is provided, which registers a pressure in one of the first or second admission line.

15. A suspension system according to claims 11 wherein the admission lines are provided with a non-return valve opening in the direction of the supply lines.

16. A suspension system according to claim 11 wherein the discharge lines are provided with one of a restrictor or orifice.

17. A suspension system according to claim 11 wherein the discharge lines are provided with a proportional discharge control valve.

18. A suspension system according to claim 1 wherein the piston-side and the piston rod-side chambers of the hydraulic cylinders are each provided with a resettable non-return valve, the non-return valve opening in the direction of the respective chamber.

10. A suspension system according to clam 1 wherein the supply or connecting lines are provided with pressure switches.