US4769758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Antiskid control system responsive to road surface reaction
Assignee: Denso Corp
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Filing: 1986-04-11
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Granted: 1988-09-06
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Expires: 2006-04-11
Abstract
Abstract Disclosed is an antiskid control system for a vehicle wherein the rotational acceleration of a wheel of the vehicle is detected and the rate of variation of the detected acceleration is detected upon the onset of speed reduction of the wheel. A pressure modulator, which is located in a hydraulic line between a master cylinder and a wheel cylinder, is responsive to the detected rate of variation of acceleration to provide a pressure relief action on the fluid pressurized by the master cylinder and supplies the modulated fluid to the wheel brake cylinder.
Inventors
- 👤 Shouichi Masaki
- 👤 Hiromi Maehata
- 👤 Ken Asami
- 👤 Kazunori Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:10
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/176; B60T8/1761; B60T8/17616; B60T8/32; B60T8/58
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
125 words
An antiskid control system for a vehicle having a hydraulic master cylinder responsive to depression of a brake pedal for applying hydraulic pressure to a hydraulic brake cylinder of a wheel of the vehicle and pressure modulating means located between said master and brake cylinders, comprising: acceleration detecting means for detecting the rotational acceleration of said wheel; means for detecting when said acceleration decreases below a predetermined value and differentiating said acceleration upon the detection of said acceleration decreasing below the predetermined value to derive a rate of variation of acceleration; and control means for causing said pressure modulating means to provide a pressure relief action to decrease said hydraulic pressure to said wheel by an amount based on said rate of variation of acceleration.
Claim 2
Dependent Claim
125 words
An antiskid control system for a vehicle having a hydraulic master cylinder responsive to depression of a brake pedal for applying hydraulic pressure to a hydraulic brake cylinder of a wheel of the vehicle and pressure modulating means located between said master and brake cylinders, comprising: acceleration detecting means for detecting the rotational acceleration of said wheel; means for detecting when said acceleration decreases below a predetermined value and differentiating said acceleration upon the detection of said acceleration decreasing below the predetermined value to derive a rate of variation of acceleration; and control means for causing said pressure modulating means to provide a pressure relief action to decrease said hydraulic pressure to said wheel by an amount based on said rate of variation of acceleration.
Claim 3
Dependent Claim
51 words
An antiskid control system as claimed in claim 1, wherein said control means causes said modulating means to operate in a pressure relief mode for an interval which is variable as a function of said rate of variation, so that the hydraulic pressure decreases at a constant rate during said interval.
Claim 4
Dependent Claim
156 words
An antiskid control system for a vehicle having a hydraulic master cylinder responsive to depression of a brake pedal for applying hydraulic pressure to a brake cylinder of a wheel of the vehicle and pressure modulating means located between said master and brake cylinders, comprising: acceleration detecting means for detecting the rotational acceleration of said wheel; means for detecting when said acceleration decreases below a predetermined value representing an onset of speed reduction of said wheel; means for detecting the rate of variation of said acceleration during a first interval following the detection of said acceleration decreasing below said predetermined value; and control means for causing said pressure modulating means to operate in a pressure relief mode during said first interval to decrease said hydraulic pressure at a constant rate, and subsequently causing said modulating means to operate continuously in said pressure relief mode for a second interval based on said rate of variation of acceleration.
Claim 5
Dependent Claim
156 words
An antiskid control system for a vehicle having a hydraulic master cylinder responsive to depression of a brake pedal for applying hydraulic pressure to a brake cylinder of a wheel of the vehicle and pressure modulating means located between said master and brake cylinders, comprising: acceleration detecting means for detecting the rotational acceleration of said wheel; means for detecting when said acceleration decreases below a predetermined value representing an onset of speed reduction of said wheel; means for detecting the rate of variation of said acceleration during a first interval following the detection of said acceleration decreasing below said predetermined value; and control means for causing said pressure modulating means to operate in a pressure relief mode during said first interval to decrease said hydraulic pressure at a constant rate, and subsequently causing said modulating means to operate continuously in said pressure relief mode for a second interval based on said rate of variation of acceleration.
Claim 6
Dependent Claim
46 words
An antiskid control system as claimed in claim 3, wherein said control means comprises means for producing a value indicative of said second interval based on the detected wheel acceleration according to a function describing the relationship between said detected wheel acceleration and said second interval.
Claim 7
Dependent Claim
41 words
An antiskid control system as claimed in claim 4, wherein said control means comprises means for storing a plurality of data each representing a different value of said second interval in locations addressable as a function of said detected wheel acceleration.
Claim 8
Independent Claim
115 words
A method for controlling a hydraulic pressure modulator for modulating hydraulic pressure of fluid supplied from a hydraulic master cylinder in response to depression of a brake pedal to a wheel brake cylinder which applies a braking force on a vehicle wheel, comprising the steps of: detecting the rotational acceleration of said wheel; detecting when said acceleration reaches a predetermined threshold representing an onset of speed reduction of said wheel; detecting a rate of variation of said acceleration upon the detection of said acceleration reaching said threshold; and causing said pressure modulating means to operate in a pressure relief mode to decrease said hydraulic pressure by an amount based on the detected rate of variation.
Claim 9
Independent Claim
115 words
A method for controlling a hydraulic pressure modulator for modulating hydraulic pressure of fluid supplied from a hydraulic master cylinder in response to depression of a brake pedal to a wheel brake cylinder which applies a braking force on a vehicle wheel, comprising the steps of: detecting the rotational acceleration of said wheel; detecting when said acceleration reaches a predetermined threshold representing an onset of speed reduction of said wheel; detecting a rate of variation of said acceleration upon the detection of said acceleration reaching said threshold; and causing said pressure modulating means to operate in a pressure relief mode to decrease said hydraulic pressure by an amount based on the detected rate of variation.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |