Vehicle suspension apparatus

• US 4,846,496 A
• Filed: 01/07/1988
• Issued: 07/11/1989
• Est. Priority Date: 01/24/1984
• Status: Expired due to Term

• Current Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Original Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Abe, Hiroki, Takeuchi, Shinichi, Kumagai, Naotake, Suzumura, Masanaga, Chikamori, Sunao, Tanaka, Tadao, Harara, Mitsuhiko, Tatemoto, Minoru
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): CULBRETH, ERIC D
• Application Number:
  US07/141,425
• Time in Patent Office: 551 Days
• Field of Search: 280/689, 280/707, 280/772, 280/DIG. 1, 280/6 H, 280/6 R, 364/424, 180/143, 180/282
• US Class Current: 280/5.506
• CPC Class Codes: B60G 17/0155 pneumatic unit
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• 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 17/0523 Regulating distributors or valves for pneumatic springs
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2400/821 Uneven, rough road sensing affecting vehicle body vibration
• CPC Class Codes: B60G 2500/204 Pressure regulating valves for air-springs
• CPC Class Codes: B60G 2500/2044 Air exhausting valves
• CPC Class Codes: B60G 2500/205 Air-compressor operation
• 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 2800/162 Reducing road induced vibrations

Abstract

Wheel suspension units each having fluid spring chambers are arranged in a vehicle suspension apparatus. A roll control quantity determined in accordance with the relationship between a vehicle velocity and a steering angular velocity, i.e., inlet solenoid valves and exhaust solenoid valves, are controlled in accordance with a solenoid ON/OFF time, thereby controlling the roll of a vehicle.

Claims

1. A vehicle suspension apparatus comprising:

a suspension unit mounted on respective right and left front wheels and right and left rear wheels, each unit having a fluid spring chamber;

fluid supply means for supplying a fluid to each fluid spring chamber through a fluid supply valve;

fluid exhaust means for exhausting the fluid from each fluid spring chamber through a fluid exhaust valve;

first communicating means connecting a first communication control valve to said fluid spring chambers of said right and left front wheel suspension units;

second communicating means connecting a second communication control valve to said fluid spring chambers of said right and left rear wheel suspension units;

steering angle detecting means for detecting steering angle;

velocity detecting means for detecting a vehicle velocity;

first pressure detecting means for detecting an internal pressure of said fluid spring chambers; and

a controller for generating a communication control signal and a roll control signal when both the steering angular velocity, which is calculated from the steering angle detection by said steering angle detecting means, and the vehicle velocity, which is detected by said velocity detecting means are higher than their prescribed levels, said first and second communication control valves being closed be said communication control signal, and said fluid supply valves on the fluid spring chambers located on the contracted side with respect to a roll direction and said fluid exhaust valves in the fluid spring chambers located on the elongated side with respect to the roll direction being opened during a preset control time by said roll control signal, wherein said controller determines the length of control time in accordance with the steering angular velocity which is calculated from the steering angle detected by said steering angle detecting means and with the vehicle velocity detected by said vehicle velocity detecting means, corrects the control time on the basis of the detected internal pressure of said fluid spring chamber, and adopts said control time as said preset control time.

2. An apparatus according to claim 1, further comprising second pressure detecting means for detecting an internal pressure of a fluid source of said fluid supply means, and wherein said controller corrects said preset control time on the basis of the internal pressure of the fluid spring chamber, detected by said first pressure detecting means, and the internal pressure of the fluid source, detected by said second pressure detecting means.

3. An apparatus according to claim 1, wherein said controller is designed such that said communication control signal, by which said first and second communication control means are opened, is generated when the absolute value of the steering angle detected by said steering angle detecting means is smaller than a preset value.

4. An apparatus according to claim 1, wherein said controller is designed such that the communication control signal, by which said first and second communication control means are opened, is generated when the vehicle velocity detected by said vehicle velocity detecting means is equal to or smaller than a preset value.

5. An apparatus according to claim 1, further comprising lateral acceleration detecting means for detecting lateral acceleration acting on the vehicle body, and wherein said controller is designed such that the communication control signal, by which said first and second communication control valves are opened, is generated when the lateral acceleration detected by said lateral acceleration detecting means is equal to or smaller than a preset value.

6. An apparatus according to claim 1, wherein said controller comprises a first memory for storing a plurality of control times corresponding to the vehicle velocity and the steering angular velocity, the length of a first control time being obtained from said first memory in accordance with the detected vehicle velocity and steering angular velocity.

7. An apparatus according to claim 6, wherein said controller comprises a second memory which stores the first control time obtained from said first memory and which has contents thereof cleared when said communication control valves are open, said controller generating a supplementary roll control signal, when a first control time newly obtained from said first memory after the outputting of said roll control signal is longer than the first control time already stored in said second memory, for opening said fluid supply and exhaust valves for an additional period of time equal to the difference between the already stored first control time and the newly obtained first control time, and replacing the contents of said second memory with the newly obtained first control time.

8. A vehicle suspension apparatus comprising:

suspension units mounted on respective right and left front wheels and right and left rear wheels, each unit having a fluid spring chamber;

fluid supply means for supplying a fluid to each fluid spring chamber through a fluid supply valve;

fluid exhaust means for exhausting the fluid from each fluid spring chamber through a fluid exhaust valve;

first communicating means connecting a first communication control valve to said fluid spring chambers of said right and left front wheel suspension units;

second communicating means connecting a second communication control valve to said fluid spring chambers of said right and left rear wheel suspension units;

steering angle detecting means for detecting steering angle;

velocity detecting means for detecting a vehicle velocity;

pressure detecting means for detecting the internal pressure of a fluid source of said fluid supply means; and

a controller for generating a communication control signal and a roll control signal when both the steering angular velocity, which is calculated from the steering angle detection by said steering angle detecting means, and the vehicle velocity, which is detected by said velocity detecting means are higher than their prescribed levels, said first and second communication control valves being closed by said communication control signal, and said fluid supply valves in the fluid spring chambers located on the contracted side with respect to a roll direction and said fluid exhaust valves in the fluid spring chambers located on the elongated side with respect to the roll direction being opened during a preset control time by said roll control signal, wherein said controller determines the length of control time in accordance with the steering angular velocity which is calculated from the steering angle detected by said steering angle detecting means and with the vehicle velocity detected by said vehicle velocity detecting means, corrects the control time on th basis of the internal pressure of said fluid source, detected by said pressure detecting means, and adopts said control time as said preset control time.