Brake system having pump to start by forecast of braking
First Claim
1. A brake system of a vehicle having a vehicle body and a plurality of vehicle wheels, said brake system comprising a reservoir, a plurality of wheel cylinders each adapted to apply a braking force to a corresponding one of said plurality of vehicle wheels when supplied with a working fluid at a raised pressure, an inlet passage means adapted to supple the working fluid to said plurality of wheel cylinders, a pump means for pumping the working fluid from said reservoir to said inlet passage means to provide a predetermined raised pressure source of the working fluid in said inlet passage means, fluid circuit means including fluid flow control valves for selectively conducting the working fluid from said inlet passage means to each one of said wheel cylinders, and an automatic control means for controlling said pump means and said fluid flow control valves, wherein said automatic control means comprises means for estimating a parameter related with running of the vehicle, said parameter relating to a probable requirement for applying braking to at least one selected from said plurality of vehicle wheels by approaching a predetermined value thereof, said automatic control means controlling said pump means and said fluid flow control valves such that, when said parameter approaches said predetermined value with a predetermined proximity thereto, said pump means is started for operation thereof so as to provide said predetermined raised pressure source in said inlet passage means while said flow control valves isolate all of the wheel cylinders from said inlet passage means, and when said parameter reaches said predetermined value, the wheel cylinder or cylinders corresponding to said selected vehicle wheel or wheels are supplied with the working fluid with a rise of pressure thereof available as modified from said predetermined raised pressure source in said inlet passage means under a control of said flow control valves.
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Accused Products
Abstract
In a brake system of a vehicle adapted to be operated automatically, the brake system includes a forecasting mechanism for forecasting a need of automatic braking, and a pump to provide a source of a pressurized working fluid for the automatic braking is started when a need of an automatic braking is forecast. By such a need forecast starting of the pump, the brake system can automatically apply an effective braking to a vehicle wheel or wheels, with no accumulator for storing the pressurized working fluid. The pump need forecasting may depend upon an estimation of a turn behavior of the vehicle and/or a detection of an obstacle in front of the vehicle.
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Citations
9 Claims
- 1. A brake system of a vehicle having a vehicle body and a plurality of vehicle wheels, said brake system comprising a reservoir, a plurality of wheel cylinders each adapted to apply a braking force to a corresponding one of said plurality of vehicle wheels when supplied with a working fluid at a raised pressure, an inlet passage means adapted to supple the working fluid to said plurality of wheel cylinders, a pump means for pumping the working fluid from said reservoir to said inlet passage means to provide a predetermined raised pressure source of the working fluid in said inlet passage means, fluid circuit means including fluid flow control valves for selectively conducting the working fluid from said inlet passage means to each one of said wheel cylinders, and an automatic control means for controlling said pump means and said fluid flow control valves, wherein said automatic control means comprises means for estimating a parameter related with running of the vehicle, said parameter relating to a probable requirement for applying braking to at least one selected from said plurality of vehicle wheels by approaching a predetermined value thereof, said automatic control means controlling said pump means and said fluid flow control valves such that, when said parameter approaches said predetermined value with a predetermined proximity thereto, said pump means is started for operation thereof so as to provide said predetermined raised pressure source in said inlet passage means while said flow control valves isolate all of the wheel cylinders from said inlet passage means, and when said parameter reaches said predetermined value, the wheel cylinder or cylinders corresponding to said selected vehicle wheel or wheels are supplied with the working fluid with a rise of pressure thereof available as modified from said predetermined raised pressure source in said inlet passage means under a control of said flow control valves.
- 8. A brake system of a vehicle having a vehicle body and a plurality of vehicle wheels, said brake system comprising a reservoir, a plurality of wheel cylinders each adapted to apply a braking force to a corresponding one of said plurality of vehicle wheels when supplied with a working fluid at a raised pressure, an inlet passage means adapted to supply the working fluid to said plurality of wheel cylinders, a pump means for pumping the working fluid from said reservoir to said inlet passage means to provide a predetermined raised pressure source of the working fluid in said inlet passage means, fluid circuit means including fluid flow control valves for selectively conducting the working fluid from said inlet passage means to each one of said wheel cylinders, and an automatic control means for controlling said pump means and said fluid flow control valves, wherein said automatic control means comprises means for estimating a parameter related with running of the vehicle, said parameter relating to a probable requirement for applying braking to at least one selected from said plurality of vehicle wheels by approaching a predetermined value thereof, said automatic control means controlling said pump means and said fluid flow control valves such that, when said parameter approaches said predetermined value with a predetermined proximity thereto, said pump means is started for operation thereof so as to provide said predetermined raised pressure source in said inlet passage means and the wheel cylinder or cylinders corresponding to said selected vehicle wheel or wheels are supplied with the working fluid with such a preliminary partial rise of pressure thereof available by a modification of said predetermined raised pressure source under a control of said fluid flow control valves that does not yet cause any substantial braking of the corresponding vehicle wheel or wheels, and when said parameter reaches said predetermined value, the wheel cylinder or cylinders corresponding to said selected vehicle wheel or wheels are supplied with the working fluid with a further substantial rise of pressure thereof available as also modified from said predetermined raised pressure source in said inlet passage means under a control of said flow control valves.
Specification