Back to results
US 6,315,371 B1Granted
Brake system
AssigneeBosch Braking Systems Co., Ltd.
InventorsYuzi Wachi, Toshiaki Fukushima
Life of this patent
Estimating the term…
Abstract
In a brake system, a controller closes solenoid shut-off valves to shut off a communication between a master cylinder and wheel cylinders by pressing a brake pedal, and at the same time, drives a pump and controls the operation of brake fluid pressure control means to supply brake fluid through the pump to the wheel cylinders, thereby performing braking action. Idle travels of the wheel cylinders can be cancelled by the brake fluid from the pump, and a very short pedal stroke can be obtained. Since the brake characteristics are set by considering three factors, i.e. pedal characteristics, travel of a brake pedal, and deceleration (brake fluid pressure) of a vehicle, the brake system has a very short stroke of the brake pedal as compared to a conventional one and has optimal brake characteristics.
Claims20
A brake system comprising:
- a brake pedal,
- a reservoir for storing brake fluid,
- a master cylinder operated by said brake pedal for developing fluid pressure and having a pressure chamber,
- brake cylinders actuated by the fluid pressure of said master cylinder,
- an electromagnetic shut-off valve disposed between the pressure chamber of the master cylinder and the reservoir,
- brake fluid supply means for supplying brake fluid to lines between the brake cylinders and the pressure chamber of the master cylinder,
- brake fluid pressure control means for controlling the fluid pressure in the brake cylinders, and
- a central processor electrically connected to the electromagnetic shut-off valve, the brake fluid supply means and the brake fluid pressure control means for controlling the same, said central processor, when the brake pedal is depressed, controlling the electromagnetic shut-off valve and the brake fluid pressure control means in such a manner as to obtain a preset pedal force/pedal travel characteristic, and controlling the brake fluid supply means and the brake fluid pressure control means in such a manner as to obtain a preset pedal force/vehicle deceleration characteristic, said pedal force/pedal travel characteristic having a characteristic point where a pedal travel is 7-15 mm while a pedal force is 15-25N, and said pedal force/vehicle deceleration characteristic having a characteristic point where a vehicle deceleration is 0.08-0.12G while the pedal force is 15-25N.
5 more elements
A brake system comprising:
- a brake pedal,
- a reservoir for storing brake fluid,
- a master cylinder operated by said brake pedal for developing fluid pressure and having a pressure chamber,
- brake cylinders actuated by the fluid pressure of said master cylinder,
- an electromagnetic shut-off valve disposed between the pressure chamber of the master cylinder and the brake cylinders,
- brake fluid supply means for supplying brake fluid to lines between the electromagnetic shut-off valve and the brake cylinders,
- brake fluid pressure control means for controlling the fluid pressure at the brake cylinders, and
- a central processor electrically connected to the electromagnetic shut-off valve, the brake fluid supply means and the brake fluid pressure control means for controlling the same, said central processor, when the brake pedal is depressed, controlling said electromagnetic shut-off valve and said brake fluid pressure control means in such a manner as to obtain a preset pedal force/pedal travel characteristic, and controlling said brake fluid supply means and said brake fluid pressure control means in such a manner as to obtain a preset pedal force/vehicle deceleration characteristic, said pedal force/pedal travel characteristic having a characteristic point where a pedal travel is 7-15 mm while a pedal force is 15-25N, and said pedal force/vehicle deceleration characteristic having a characteristic point where a vehicle deceleration is 0.08-0.12G while the pedal force is 15-25N.
5 more elements
A brake system comprising:
- a brake pedal,
- a reservoir for storing brake fluid,
- a master cylinder operated by said brake pedal for developing fluid pressure and having a pressure chamber,
- brake cylinders actuated by the fluid pressure of said master cylinder,
- a first electromagnetic shut-off valve disposed between the pressure chamber of the master cylinder and the reservoir,
- a second electromagnetic shut-off valve disposed between the pressure chamber of the master cylinder and the brake cylinders,
- brake fluid supply means for supplying brake fluid to lines between the second electromagnetic shut-off valve and the brake cylinders,
- brake fluid pressure control means for controlling the fluid pressure at the brake cylinders, and
- a central processor for controlling the first and second electromagnetic shut-off valves, the brake fluid supply means, and the brake fluid pressure control means, said central processor, when the brake pedal is depressed, controlling said first and second electromagnetic shut-off valves in such a manner as to obtain a preset pedal force/pedal travel characteristic, and controlling said brake fluid supply means and said brake fluid pressure control means in such a manner as to obtain a preset pedal force/vehicle deceleration characteristic, said pedal force/pedal travel characteristic having a characteristic point where a pedal travel is 7-15 mm while a pedal force is 15-25N, and said pedal force/vehicle deceleration characteristic having a characteristic point where a vehicle deceleration is 0.08-0.12G while the pedal force is 15-25N.
6 more elements
Dependencies are inferred from the claim text.