SUSPENSION APPARATUS

• US 20120247888A1
• Filed: 03/21/2012
• Published: 10/04/2012
• Est. Priority Date: 03/30/2011
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Uchiyama, Masaaki, CHIKUMA, Hiroshi, Hirao, Ryusuke, Ichimaru, Nobuyuki
• Granted Patent: US 9,731,575 B2
• Time in Patent Office: Days
• US Class Current: 188/266.1
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2400/10 Acceleration; Deceleration
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: F16F 9/468 controlling at least one bypass to main flow path

Abstract

Shock absorbers of left and right front wheel suspensions and shock absorbers of left and right rear wheel suspensions each are constituted by a damping force adjustable hydraulic shock absorber provided with a frequency response unit. An actuator of a damping force variable mechanism provided to the shock absorber is driven and controlled by a controller. The controller variably adjusts the damping force between the soft side and the hard side by the damping force variable mechanism according to a vertical vibration when a vehicle body vertically vibrates at a low frequency. The controller does not adjust the damping force when the vehicle body vibrates at a higher frequency than the low frequency.

Claims

1. A suspension apparatus comprising:

a shock absorber disposed between a vehicle body side and a wheel side of a vehicle, the shock absorber being capable of adjusting a damping force by an actuator; and

a controller configured to adjust the actuator,

wherein the shock absorber includes a frequency response unit configured to reduce the damping force when a high-frequency vibration occurs, and

wherein the controller adjusts the damping force according to a movement state when a movement of a low frequency occurs among movements of the vehicle, and the controller does not adjust the damping force according to the movement state or adjusts the damping force at a smaller level than a damping force adjustment level for the movement of the low-frequency when a movement of a higher frequency than the low frequency occurs.

2. The suspension apparatus according to claim 1, wherein the movement of the low frequency is at least any one of a roll movement, a pitch movement, and a heave movement, which are movements of the vehicle.

3. The suspension apparatus according to claim 2, further comprising a posture change detector configured to detect the roll movement, the pitch movement, and the heave movement of the vehicle, the posture changer detector comprising an operation state detector configured to detect a drivers'"'"' operation.

4. The suspension apparatus according to claim 1, wherein the movement state is a vertical vibration of the vehicle,

wherein the controller adjusts the damping force according to the vertical vibration of the vehicle when the vehicle vertically vibrates at the low frequency, and the controller adjusts the damping force at the smaller level than the damping force adjustment level of the movement of the low-frequency when the vehicle vertically vibrates at the higher frequency than the low frequency.

5. The suspension apparatus according to claim 1, wherein the movement state is a vertical vibration of the vehicle,

wherein the controller adjusts the damping force according to the vertical vibration of the vehicle when a vertical vibration at a predetermined low frequency occurs among vertical vibrations of the vehicle.

8. The suspension apparatus according to claim 1, wherein the shock absorber includes a damping force generation unit adjustable by the actuator, and

wherein the frequency response unit includes a bypass passage for bypassing the damping force generation unit, and a free piston movably disposed in the bypass passage.

6. A suspension apparatus comprising:

a shock absorber disposed between a vehicle body side and a wheel side of a vehicle, the shock absorber being capable of adjusting a damping force by an actuator; and

a controller configured to adjust the actuator,

wherein the shock absorber includes a frequency response unit configured to reduce the damping force when a high-frequency vibration occurs

wherein the vehicle includes a posture change detector configured to detect at least any one of a roll movement, a pitch movement, and a heave movement of the vehicle, and

wherein the controller adjusts the damping force according to a posture state of the vehicle detected by the posture change detector.

9. The suspension apparatus according to claim 6, wherein the shock absorber includes a damping force generation unit adjustable by the actuator, and

wherein the frequency response unit includes a bypass passage for bypassing the damping force generation unit, and a free piston movably disposed in the bypass passage.

7. A suspension apparatus comprising:

a shock absorber disposed between a vehicle body side and a wheel side of a vehicle, the shock absorber being capable of adjusting a damping force by an actuator; and

a controller configured to adjust the actuator,

wherein the shock absorber includes a frequency response unit configured to reduce the damping force when a high-frequency vibration occurs,

wherein the vehicle includes a vibration detector configured to detect a vibration of the vehicle,

wherein the controller adjusts the damping force according to a detection value of the vibration detector when the vibration detector detects a vibration of a low frequency, and the controller adjusts the damping force according to the detection value of the vibration detector at a smaller level when the vibration detector detects a vibration of a higher frequency than the low frequency.

10. The suspension apparatus according to claim 7, wherein the shock absorber includes a damping force generation unit adjustable by the actuator, and

wherein the frequency response unit includes a bypass passage for bypassing the damping force generation unit, and a free piston movably disposed in the bypass passage.