Stabilizer device

• US 20050077696A1
• Filed: 02/04/2003
• Published: 04/14/2005
• Est. Priority Date: 02/06/2002
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ogawa, Atsushi
• Granted Patent: US 7,540,505 B2
• Time in Patent Office: Days
• US Class Current: 280/124.157
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/0185 for failure detection
• CPC Class Codes: B60G 21/0555 including an actuator inducing vehicle roll
• CPC Class Codes: B60G 21/0556 including a releasable coupling B60G21/0555 takes precedence
• CPC Class Codes: B60G 2200/142 with a single lateral arm, e.g. MacPherson type
• CPC Class Codes: B60G 2202/135 Stabiliser bar and/or tube
• CPC Class Codes: B60G 2202/154 with an accumulator
• CPC Class Codes: B60G 2202/312 The spring being a wound spring
• CPC Class Codes: B60G 2202/32 The spring being in series with the damper and/or actuator
• CPC Class Codes: B60G 2204/1224 End mounts of stabiliser on wheel suspension
• CPC Class Codes: B60G 2204/422 Links for mounting suspension elements
• CPC Class Codes: B60G 2206/1116 Actively adjustable during driving
• CPC Class Codes: B60G 2400/0511 Roll angle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/25 Stroke; Height; Displacement
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2500/20 Spring action or springs
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60G 2800/012 : Rolling condition
• CPC Class Codes: B60G 2800/80 : Detection or control after a system or component failure
• CPC Class Codes: B60G 2800/9122 : ARS - Anti-Roll System Control

Abstract

A stabilizer system including stabilizer control portions which change respective elastic forces of front-wheel-side and rear-wheel-side stabilizer bars. When an abnormality occurs to one of the stabilizer control portions, the other control portion is controlled according to a changed control rule corresponding to the abnormality. In the case where the front-wheel-side stabilizer control portion 20 is abnormally fixed to a damping-force producing mode, the rear-wheel-side stabilizer control portion 22 is controlled to the damping-force producing mode. In the case where the front-wheel-side stabilizer control portion 20 is abnormally fixed to an elastic-force producing mode, the rear-wheel-side stabilizer control portion 22 is controlled according to a normal control rule. Since the control rule is changed according to the nature of the abnormality, the vehicle can enjoy improved running stability.

Claims

1. A stabilizer system comprising

a stabilizer bar;

a stabilizer control portion which corresponds to the stabilizer bar and is controllable, based on a running condition of a vehicle, to control an elastic force of the stabilizer bar; and

a control-rule changing portion which changes, when the stabilizer system is brought into an unusual, special state, a control rule according to which the stabilizer control portion is controlled.

2. The stabilizer system according to claim 1, wherein the control-rule changing portion comprises:

a special-state identifying portion which identifies the special state of the stabilizer system; and

a special-state-related changing portion which changes the control rule, such that the changed control rule corresponds to the special state identified by the special-state identifying portion.

3. The stabilizer system according to claim 1, wherein the control-rule changing portion comprises a force-related changing portion which changes, when a force exerted to the stabilizer bar exceeds a pre-set value that is unusually great, the control rule that has been used before the force exceeds the pre-set value.

4. The stabilizer system according to claim 1, wherein the control-rule changing portion comprises an elastic-force decreasing portion which changes, when a force exerted to the stabilizer bar exceeds a pre-set value, the control rule such that according to the changed control rule, the stabilizer control portion is controlled, independent of the running condition of the vehicle, to decrease the elastic force of the stabilizer bar such that the decreased elastic force is smaller than the elastic force when the force exceeds the pre-set value.

5. The stabilizer system according to claim 3, wherein the control-rule changing portion further comprises a force detecting portion which detects the force exerted to the stabilizer bar.

6. The stabilizer system according to claim 1, comprising a plurality of said stabilizer bars and a plurality of said stabilizer-control portions which correspond to the stabilizer bars respectively and are controllable, based on the running condition of the vehicle, to control respective elastic forces of the stabilizer bars, wherein the control-rule changing portion comprises an abnormality-related changing portion which changes, when an abnormality occurs to one of the stabilizer control portions, a control rule or rules according to which the other stabilizer control portion or portions than said one stabilizer control portion is or are controlled, such that the changed control rule or rules corresponds or correspond to the abnormality.

7. The stabilizer system according to claim 1, wherein the stabilizer control portion is switchable to each of at least two modes selected from the group consisting of an elastic-force producing mode in which the stabilizer control portion causes the stabilizer bar to produce the elastic force corresponding to an amount of a relative movement of a left wheel and a right wheel of the vehicle in a vertical direction, a damping force producing mode in which the stabilizer control portion produces a damping force corresponding to a speed of a relative movement of a left wheel and a right wheel of the vehicle in a vertical direction, a relative-movement allowing mode in which the stabilizer control portion allows a free relative movement of a left wheel and a right wheel of the vehicle in a vertical direction, and a relative-movement restraining mode in which the stabilizer control portion restrains a relative movement of a left wheel and a right wheel of the vehicle in a vertical direction.

8. The stabilizer system according to claim 1, wherein the stabilizer control portion is switchable to each of an elastic-force producing mode in which the stabilizer control portion causes the stabilizer bar to produce the elastic force corresponding to an amount of a relative movement of a left wheel and a right wheel of the vehicle in a vertical direction, and a damping force producing mode in which the stabilizer control portion produces a damping force corresponding to a speed of a relative movement of a left wheel and a right wheel of the vehicle in a vertical direction.

9. The stabilizer system according to claim 1, wherein the stabilizer control portion comprises:

a hydraulic-cylinder device including a housing and a piston which is slideably fitted in the housing; and

an electromagnetic control valve which is switchable to a communication position thereof in which the control valve allows a communication between two liquid chambers that are separated from each other by the piston in the housing, and a shut-off position thereof in which the control valve shuts off the communication between the two liquid chambers.

10. The stabilizer system according to claim 9, wherein the stabilizer control portion further comprises a flow restrictor which is provided such that the flow restrictor is located between the two liquid chambers in a state in which the electromagnetic control valve is in the communication position thereof in which the control valve allows the communication between the two liquid chambers.

11. The stabilizer system according to claim 9, wherein one of the housing, and a piston rod of the piston, of the hydraulic-cylinder device is connected to the stabilizer bar, and the other of the housing and the piston rod is connected to a member which is located on a side of a wheel of the vehicle.

12. The stabilizer system according to claim 9, wherein the stabilizer bar is separated into two portions, and wherein the housing of the hydraulic-cylinder device is connected to one of the two portions of the stabilizer bar, and a piston rod of the piston of the hydraulic-cylinder device is connected to the other portion of the stabilizer bar.

13. The stabilizer system according to claim 9, wherein the stabilizer control portion further comprises a relief valve which is provided parallel to the electromagnetic control valve and which is mechanically switched, when a liquid pressure in one of the two liquid chambers exceeds a pre-set value, from a shut-off position thereof in which the relief valve shuts off the communication between the liquid chambers, to a communication position thereof in which the relief valve allows the communication between the liquid chambers.

14. A suspension system comprising

a stabilizer bar;

a stabilizer control portion which changes an elastic force of the stabilizer bar;

a different control portion than the stabilizer control portion; and

an abnormality-related rolling-characteristic control portion which controls, when an abnormality occurs to one of the stabilizer control portion and the different control portion, a rolling characteristic of a vehicle, by controlling the other of the stabilizer control portion and the different control portion.

15. A steering-angle-control apparatus for controlling a steering angle of at least one of a front wheel and a rear wheel, based on a state of a steering member that is operated by a driver, the steering-angle control apparatus comprising;

a control-rule changing portion which changes, when an abnormality occurs to a stabilizer control portion which controls an elastic force of a stabilizer bar, a control rule according to which the steering angle of said at least one of the front and rear wheels is controlled.

16. A relative-movement control apparatus for controlling a relative movement of a first member and a second member, the relative-movement control apparatus being provided between the first and second members and being switchable to a relative-movement inhibiting mode in which the relative-movement control apparatus inhibits the relative movement of the first and second members, and a damping-force producing mode in which the relative-movement control apparatus allows the relative movement of the first and second members so as to produce a damping force, the improvement comprising

when an abnormality occurs, the relative-movement control apparatus is switched to a pre-selected one of the relative-movement inhibiting mode and the damping-force producing mode.