← Back to Patent Explorer
US4787649A Expired / Lapsed US ⏱️ 0.0 years remaining

Vehicle suspension system

Assignee: Mazda Motor Corp
•
Filing: 1987-08-04
•
Granted: 1988-11-29
•
Expires: 2007-08-04
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The suspension system of the present invention comprises support means installed between a wheel and the vehicle body exerting suspension force which can be changed irrespective of relative displacement between the wheel and the vehicle body. According to low frequency components of a parameter which respresents changing condition of the relative displacement, the support means is controlled to exert a suspension force in such a way that the relative displacement can be suppressed. Such parameters include the relative displacement and the rate of the change thereof. According to the present invention, suspension characteristics can be maintained to maintain riding qualities and rolling and pitching properties in a preferable condition throughout all running conditions.

Inventors

  • 👤 Kenichi Watanabe
  • 👤 Shin Takehara
  • 👤 Hiroo Shimoe
  • 👤 Haruyuki Taniguchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 08:38
CPC Classifications
B; B60; B60G; B60G17/00; B60G17/015; B60G17/018

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 219 words
A vehicle suspension system for plural vehicle wheels comprising support means disposed between each wheel and a vehicle body exerting suspension force which can be changed irrespective of relative displacement between the wheel and the vehicle body, a separate sensing means for each wheel for detecting one of the parameters representing changing condition of the relative displacement between the wheel and the vehicle body, control means for controlling the respective support means when supplied with a signal from the respective sensing means, by extracting low frequency components therefrom and, according these components, controlling the support means to exert the suspension force in such a way that said relative displacement can be suppressed, wherein each support means includes a fluid actuator having a fluid cylinder disposed between the respective wheel and the vehicle body, the system further including a fluid reservoir, pumping means for supplying pressurized fluid from the reservoir to the respective fluid cylinders, and a separate valve means interposed between the pump means and the respective cylinders for controlling fluid flow applied to and discharged from the respective cylinders, and wherein said control means controls each of said valve means so that pressurized fluid is applied to and discharged from each of said cylinders to exert suspension forces from each fluid actuator according to each of said displacements.
Claim 2
Dependent Claim 219 words
A vehicle suspension system for plural vehicle wheels comprising support means disposed between each wheel and a vehicle body exerting suspension force which can be changed irrespective of relative displacement between the wheel and the vehicle body, a separate sensing means for each wheel for detecting one of the parameters representing changing condition of the relative displacement between the wheel and the vehicle body, control means for controlling the respective support means when supplied with a signal from the respective sensing means, by extracting low frequency components therefrom and, according these components, controlling the support means to exert the suspension force in such a way that said relative displacement can be suppressed, wherein each support means includes a fluid actuator having a fluid cylinder disposed between the respective wheel and the vehicle body, the system further including a fluid reservoir, pumping means for supplying pressurized fluid from the reservoir to the respective fluid cylinders, and a separate valve means interposed between the pump means and the respective cylinders for controlling fluid flow applied to and discharged from the respective cylinders, and wherein said control means controls each of said valve means so that pressurized fluid is applied to and discharged from each of said cylinders to exert suspension forces from each fluid actuator according to each of said displacements.
Claim 3
Dependent Claim 47 words
The vehicle suspension system as set forth in claim 1, wherein said low frequency components of the relative displacement between the respective wheel and the vehicle body are those below a specific frequency which is equal to or near the resonance frequency of the upper side mass.
Claim 4
Dependent Claim 24 words
The vehicle suspension system as set forth in claim 1, wherein said parameter is relative displacement between the respective wheel and the vehicle body.
Claim 5
Dependent Claim 30 words
The vehicle suspension system as set forth in claim 1, wherein said parameter is the rate of the change in the relative displacement between the wheel and the vehicle body.
Claim 6
Dependent Claim 29 words
The vehicle suspension system as set forth in claim 4, wherein said rate of change is obtained by differentiating the relative displacement which is detected by the sensing means.
Claim 7
Dependent Claim 31 words
The vehicle suspension msystem as set forth in claim 1, wherein said control means includes a low pass filter means which passes therethrough low frequency components of the detected relative displacement.
Claim 8
Dependent Claim 27 words
The vehicle suspension system as set forth in claim 6, wherein said low pass filter means consists of an analog circuit having a resistance and a capacitor.
Claim 9
Dependent Claim 18 words
The vehicle suspension system as set forth in claim 1, wherein each said actuator comprises a hydraulic actuator.
Claim 10
Dependent Claim 24 words
The vehicle suspension system as set forth in claim 1, which further comprises pressure sensing means for sensing the pressure in each said actuator.
Claim 11
Dependent Claim 33 words
The vehicle suspension system as set forth in claim 9, wherein each said valve means is controlled in a closed-loop by said control means according to the output of said pressure sensing means.
Claim 12
Dependent Claim 22 words
The vehicle suspension system as set forth in claim 1, wherein each cylinder defines a fluid chamber communicating with air spring means.
Claim 13
Dependent Claim 48 words
The vehicle suspension means as set forth in claim 1, wherein each said valve means is of a change-over type having a first position for supplying fluid to respective actuator, a second position for discharging fluid from said actuator, and a third position for halting the fluid flow.
Claim 14
Dependent Claim 39 words
The vehicle suspension system as set forth in claim 1, wherein each said valve means is of a flow control type that controls the amount of fluid passing therethrough according to the value of the driving signal applied thereon.
Claim 15
Dependent Claim 122 words
A vehicle suspension system comprising hydraulic actuator means disposed between a wheel and a vehicle body exerting suspension force which can be changed irrespective of any relative displacement between the wheel and the vehicle body, sensing means for detecting relative displacement between the wheel and the vehicle body, control means for controlling the hydraulic actuator means which includes low pass filter means to extract low frequency components from the detected relative displacement by the sensing means and, according to these components, controls the hydraulic actuator means to exert the suspension force in such a way that said relative displacement can be suppressed, said hydraulic actuator means having fluid pumping means and valve means disposed between said actuator and said fluid pumping means.
Claim 16
Dependent Claim 122 words
A vehicle suspension system comprising hydraulic actuator means disposed between a wheel and a vehicle body exerting suspension force which can be changed irrespective of any relative displacement between the wheel and the vehicle body, sensing means for detecting relative displacement between the wheel and the vehicle body, control means for controlling the hydraulic actuator means which includes low pass filter means to extract low frequency components from the detected relative displacement by the sensing means and, according to these components, controls the hydraulic actuator means to exert the suspension force in such a way that said relative displacement can be suppressed, said hydraulic actuator means having fluid pumping means and valve means disposed between said actuator and said fluid pumping means.
Claim 17
Dependent Claim 62 words
The vehicle suspension system as set forth in claim 14, wherein said hydraulic actuator means includes a fluid chamber and an air spring communicated thereto, and wherein said valve means is a flow control valve which controls the amount of the fluid passing therethrough to and from said fluid chamber according to the value of the detected signal by said sensor means.
Claim 18
Dependent Claim 48 words
The vehicle suspension system as set forth in claim 15, wherein said low pass filter means passes only low frequency components of the detected relative displacement below a specific frequency which is equal to or near the resonance frequency of the upper side mass of the suspension system.

References Cited (Backward Citations)

FR2401037A1 Cited
EP0027869A2 Cited
JPS5914365A Cited
EP0114757A1 Cited
EP0151421A2 Cited
US4600215A Cited
EP0162449A2 Cited
EP0162448B1 Cited
US4667978A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-11-29 1992-05-30 1992-11-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-11-29 1996-05-30 1996-11-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-11-29 2000-05-30 2000-11-29 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag