Suspension device for automobile

• US 4,648,622 A
• Filed: 06/10/1986
• Issued: 03/10/1987
• Est. Priority Date: 08/24/1983
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Takada, Hiroyuki, Maruyama, Mitsunori, Wada, Shunichi, Kumagai, Naotake, Harara, Mitsuhiko, Tatemoto, Minoru, Shimomura, Setsuhiro, Takizawa, Shozo
• Primary Examiner(s): Love, John J.
• Assistant Examiner(s): Weaver, Ross
• Application Number:
  US06/873,160
• Time in Patent Office: 273 Days
• Field of Search: 280/705, 280/707, 280/714, 180/41, 267/64.16, 267/64.25, 364/424
• US Class Current: 280/5.519
• CPC Class Codes: B60G 17/0165 to an external condition, e.g. rough road surface, side wind
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/82 Ground surface
• CPC Class Codes: B60G 2400/821 Uneven, rough road sensing affecting vehicle body vibration
• CPC Class Codes: B60G 2401/14 Photo or light sensitive means, e.g. Infrared
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2500/22 Spring constant
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/14 Differentiating means, i.e. differential control
• CPC Class Codes: B60G 2600/60 Signal noise suppression; Electronic filtering means
• CPC Class Codes: B60G 2600/70 Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60G 2800/162 Reducing road induced vibrations
• CPC Class Codes: B60G 2800/916 Body Vibration Control

Abstract

A suspension device for automobile performs changing-over of the damping force of a shock absorber and the spring constant of a suspension spring by an output from an acceleration sensor or an output from a road clearance sensor mounted on the vehicle body. The changing operation is not performed by magnitude of an output but is performed only when an output greater that a predetermined level continues for a predetermined time period to avoid unnecessary change-over operations of the suspension characteristic during cruising a rough road.

Claims

1. A suspension device for an automobile, comprising:

a shock absorber provided with a damping force change-over mechanism;

sensor means including means for detecting horizontal and vertical vibration of the vehicle body; and

control device which detects a sustaining time period of an output of said sensor means exceeding a determination value, said control device outputting a change-over for changing a damping force of said shock absorber to a large value only when said sustaining time period exceeds a predetermined time period, and outputting a signal for maintaining the damping force of said shock absorber to be a large value for a predetermined time period even through the output of said sensor disappears.

2. The suspension device according to claim 1, wherein said means for detecting horizontal and vertical vibrations in the vehicle body include a vibratory acceleration detecting means.

3. The suspension device according to claim 2, wherein said vibratory acceleration sensor for detecting vibrations in the vehicle body outputs a signal only when the vibratory acceleration exceeds a predetermined value.

4. The suspension device according to claim 1, wherein said sensor means further includes a road clearance sensor for detecting road clearance of the vehicle.

5. A suspension for an automobile, comprising a shock absorber provided with a damping force change-over mechanism;

a self-suspension spring provided with a spring constant change-over mechanism;

sensor means including means for detecting horizontal and vertical vibrations of the vehicle body; and

control device which detects a sustaining time period of an output of said sensor means exceeding a determination value, said control device outputting a change-over signal to change at least one of the damping force of said shock absorber and the spring constant of said spring to be a large value only when said sustaining time period continues for a predetermined time period, and outputting a signal for maintaining said at least one of the damping force of said shock absorber and the spring constant of said spring to be the large value for a predetermined time even though the output of said sensor disappears.