Suspension control device

• US 5,072,965 A
• Filed: 05/30/1990
• Issued: 12/17/1991
• Est. Priority Date: 05/31/1989
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ohtagaki, Shigeki, Wada, Shunichi
• Primary Examiner(s): Rice, Kenneth R.
• Assistant Examiner(s): GRAYSAY, TAMARA L
• Application Number:
  US07/530,526
• Time in Patent Office: 566 Days
• Field of Search: 280/707, 280/724, 280/714, 280/688, 280/702, 280/703, 364/424.05
• US Class Current: 280/5.515
• CPC Class Codes: B60G 17/017 characterised by their use when the vehicle is stationary, e.g. during loading, engine start-up or switch-off
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/412 of steering wheel or column
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2400/62 Seat occupation; Passenger presence
• CPC Class Codes: B60G 2400/91 Frequency
• CPC Class Codes: B60G 2400/952 of door or bonnet
• CPC Class Codes: B60G 2500/102 stepwise
• CPC Class Codes: B60G 2600/04 Means for informing, instructing or displaying
• CPC Class Codes: B60G 2600/18 Automatic control means

Abstract

A suspension control device including a control device for variably controlling a damping force of a suspension to an optimum value by determining a magnitude of acceleration is vertical opposite directions of a vehicle body which magnitude is equal to or greater than a predetermined level and measuring the accumulated duration time of a sprung resonance which is detected by a cycle of vibration of the vehicle body from a timing of the determination of the magnitude. In another aspect, the suspension control device includes a control device for outputting a command for increasing a damping force when a magnitude of acceleration in vertical opposite directions of a vehicle body is determined to be equal to or greater than a predetermined level, and measuring the number of repetitions of a sprung resonance which is detected by measuring a cycle of vibration of the vehicle body from a timing of the determination of the magnitude. The control device maintains the damping force at a high level until the vehicle is stopped and a door open condition is detected.

Claims

1. A suspension control device comprising:

acceleration detecting means for detecting acceleration in vertically opposite directions of a vehicle body,

a vehicle speed detecting means for detecting the vehicle'"'"'s cruising speed,

a door open/closed condition detecting means for detecting a door open/closed condition,

a plurality of suspension means individually provided between corresponding wheels of a vehicle and said vehicle body for supporting said vehicle body on said corresponding wheels,

damping force varying means for varying a damping force of said suspension means, and

control means for controlling said damping force varying means so as to vary the damping force of said suspension means to an optimum value when a sprung resonance is detected and the accumulated duration time thereof is judged to be equal to or greater than a predetermined time by determining a magnitude of the vertical acceleration equal to or greater than a predetermined level with respect to a reference value of an output signal from said acceleration detecting means and measuring a cycle of vibration of said vehicle body from a timing when the magnitude of the vertical acceleration is determined to be equal to or greater than the predetermined level, wherein said control means maintains the damping force thereof until said vehicle speed detecting means detects a zero speed to determine a stoppage of the vehicle and said door open/closed condition detecting means detects a door open condition.

2. A suspension control device comprising:

acceleration detecting means for detecting acceleration in vertically opposite directions of a vehicle body,

a vehicle speed detecting means for detecting the vehicle'"'"'s cruising speed,

a door open/closed condition detecting means for detecting a door open/closed condition,

a plurality of suspension means individually provided between corresponding wheels of a vehicle and said vehicle body for supporting said vehicle body on said corresponding wheels,

damping force varying means for varying a damping force of said suspension means, and

control means for controlling said damping force varying means so as to vary the damping force of said suspension means to an optimum value when a sprung resonance is detected and the number of repetitions thereof is judged to be equal to or greater than a predetermined value by determining a magnitude of the vertical acceleration equal to or greater than a predetermined level with respect to a reference value of an output signal from said acceleration detecting means and measuring a cycle of vibration of said vehicle body from a timing when the magnitude of the vertical acceleration is determined to be equal to or greater than the predetermined level, wherein said control means maintains the damping force thereof until said vehicle speed detecting means detects a zero speed to determine a stoppage of the vehicle and said door open/closed condition detecting means detects a door open condition.