초록 ▼

A vehicle braking system such as an anti-lock brake system and/or a traction control utilizes a separate solenoid-actuated, two position, three-way valve in each controlled channel of the brake system for controlling the application of pressure to the respective wheel brake circuit. The valve includ

A vehicle braking system such as an anti-lock brake system and/or a traction control utilizes a separate solenoid-actuated, two position, three-way valve in each controlled channel of the brake system for controlling the application of pressure to the respective wheel brake circuit. The valve includes a first port connected to the controlled wheel brake(s), a second port connected to an outlet of a hydraulic pump, and a third port connected to the inlet of the hydraulic pump. The valve is only moveable between a first position wherein the outlet of the pump is connected to the wheel brake to increase pressure to the wheel brake, and a second position wherein the wheel brake is connected to the inlet of the pump to decrease pressure to the wheel brake. An electronic control is provided for operating the valve to control the application of pressure to the selected wheel brakes. The control cyclically moves the valve between the first and second positions during a predetermined time period to alternately increase and decrease pressure to the wheel brake. More specifically, the control generates a pulse-width-modulated signal to modulate the time periods during which the valve is maintained in either the first or second positions to control the effective pressure to the wheel brake to obtain a net increase, decrease, or constant pressure to the wheel brake during the predetermined time period.

대표청구항 ▼

A braking system for controlling a wheel brake of at least one wheel of a wheeled vehicle comprising: a fluid pump having an inlet and an outlet; a two position, three-way valve having a first port connected to the wheel brake, a second port connected to said outlet of said pump, and a third port co

A braking system for controlling a wheel brake of at least one wheel of a wheeled vehicle comprising: a fluid pump having an inlet and an outlet; a two position, three-way valve having a first port connected to the wheel brake, a second port connected to said outlet of said pump, and a third port connected to said inlet of said pump; said valve only moveable between a first position wherein said first port is connected to said second port to increase pressure to the wheel brake, and a second position wherein said first port is connected to said third port to decrease pressure to the wheel brake; control means for operating said valve to control the application of pressure to the wheel brake, said control means including means for cyclically moving said valve between said first and second positions during a predetermined time period to alternately increase and decrease pressure to the wheel brake, said control means operable to modulate the time periods during which said valve is maintained in said first and second positions to control the effective pressure to the wheel brake to obtain a net increase, decrease, or constant pressure to the wheel brake during said predetermined time period.