Adaptive vehicle suspension system

• US 4,867,474 A
• Filed: 12/27/1988
• Issued: 09/19/1989
• Est. Priority Date: 11/23/1987
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Smith, Stanley E.
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Mar, Michael
• Application Number:
  US07/289,857
• Time in Patent Office: 266 Days
• Field of Search: 267/31, 267/32, 267/241, 280/692, 280/697, 280/699, 280/662, 280/710, 280/712, 280/6.12
• US Class Current: 280/5.507
• CPC Class Codes: B60G 11/465 with a flexible wall
• CPC Class Codes: B60G 17/033 characterised by regulating means acting on more than one spring
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2400/252 vertical
• 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: F16F 2224/0241 Fibre-reinforced plastics [FRP]

Abstract

An adaptive vehicle suspension assembly includes a transverse leaf spring mounted in series with pneumatic springs at the front and rear wheels of a motor vehicle. A control circuit includes inlet and exhaust solenoid valves to control the flow of pressurized air into or out of the pneumatic springs, providing variable spring rate and vehicle height. Vehicle sensor switch provides control of the operation of the solenoid valves in response to sensed vehicle height increasing or decreasing the spring rate and providing optimum vehicle ride, load and cornering control.

Claims

1. An adaptive suspension system for a motor vehicle providing variable spring rate characteristics comprising a frame, a pair of front wheels independently suspended on said frame, a front composite leaf spring extending transversely of and mounted on said frame between said front wheels, a separate front pneumatic spring means mounted between an end of said front spring and each of said front wheels so as to connect said front pneumatic spring means and said front leaf spring to operate solely in series between said frame and the respective front wheels, a pair of rear wheels independently suspended on said frame, a rear composite leaf spring extending transversely of and mounted on said frame between said rear wheels, a separate rear pneumatic spring means mounted between an end of said rear spring and each of said rear wheels so as to connect said rear pneumatic spring means and said rear spring to operate solely in series between said frame and the respective rear wheels, an air pressure source and a control circuit for separately regulating pressure from said source to each of said pneumatic spring means, said control circuit including separate sensing means for sensing the height of the vehicle at each of said wheels, each of said sensing means including means for respectively increasing and decreasing the pressure to the pneumatic spring means at each of said wheels in response to lowering and raising of the vehicle at the respective wheel whereby the combined spring rate of each of the pneumatic spring means and the associated leaf spring acting in series at each of said wheels is adjusted and controlled in response to road and vehicle conditions to control vehicle motion including vehicle roll and height at the front and rear wheels.

2. An adaptive suspension system for a motor vehicle providing variable spring rate characteristics comprising a frame, a pair of front wheels independently suspended on said frame, a front composite leaf spring extending transversely of and mounted on said frame between said front wheels, a separate front pneumatic spring means mounted between an end of said front spring and each of said front wheels so as to connect said front pneumatic spring means and said fronft leaf spring to operate solely in series between said frame and the respective front wheels, a pair of rear wheels independently suspended on said frame, a rear composite leaf spring extending transversely of and mounted on said frame between said rear wheels, a separate rear pneumatic spring means mounted between an end of said rear spring and each of said rear wheels so as to connect said rear pneumatic spring means and said rear spring to operate solely in series between said frame and the respective rear wheels, an air pressure source and a control circuit for separately regulating pressure from said source to each of said pneumatic spring means, said control circuit including separate sensing means for sensing the height of the vehicle at each of said wheels, each of said sensing means including a separate switch means for respectively increasing and decreasing the pressure to the pneumatic spring means at each of said wheels in response to lowering and raising of the vehicle at the respective wheel whereby the combined spring rate of each of the pneunmatic spring means and the associated leaf spring acting in series at each of said wheels is adjusted and controlled in response to road and vehicle conditions to control vehicle motion including vehicle roll and height at the front and rear wheels.