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US 2002/0117894 A1Published application
Brake servo unit control device
AssigneeHitachi, Ltd.
InventorsSatoru Kuragaki, Tokuji Yoshikawa, Atsushi Yokoyama, Toshio Manaka
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AssigneeHitachi, Ltd.
InventorsSatoru Kuragaki, Tokuji Yoshikawa, Atsushi Yokoyama, Toshio Manaka
Estimating the term…
The solenoid current increases at low temperatures and decreases at high temperatures because the modulus of elasticity of an elastically deformable valve body and the slide resistance of an elastically deformable seal member vary with temperatures. Therefore the solenoid current for opening the valve mechanism from a closed position is required to be changed with low and high temperatures. To supply the solenoid current necessary for opening the valve mechanism without directly measuring the temperature, the solenoid current (the boost starting current leaning value) indicated when the pressure varies with the opening of the valve mechanism is recorded at the time of pressure-increasing, and thereafter when the valve mechanism is opened again after the closing of the valve mechanism, the solenoid current computed on the basis of the pressure-increase starting current learning value thus recorded is supplied.
A brake servo unit having at least a function to output a pressure increased on the basis of a brake pedal input pressure, and a function to increase and decrease an output pressure by supplying an electromagnetic force to a control valve, wherein said brake servo unit changes the initial value of the current supplied to an electromagnet when the pressure is supplied into a master cylinder at the first time after a control device is started, and the initial value of the current supplied to an electromagnet when the pressure is supplied into said master cylinder at the second time and after.
A brake servo unit having at least a function to output a pressure increased on the basis of a brake pedal input pressure, and a function to increase and decrease an output pressure by supplying an electromagnetic force to a control valve, wherein said brake servo unit changes the initial value of the current supplied to an electromagnet when the master cylinder pressure is decreased after a control device is started, and the initial value of the current supplied to said electromagnet when said master cylinder pressure is decreased at the subsequent time and after.
A method of operating a brake servo unit having at least a function to output a pressure increased on the basis of a brake pedal input pressure and a function to increase and decrease an output pressure by supplying an electromagnetic force to a control valve,
A vehicle mounted with a brake servo unit having at least a function to output a pressure increased on the basis of a brake pedal input pressure and a function to increase and decrease an output pressure by supplying an electromagnetic force to a control valve, and
Dependencies are inferred from the claim text.