Patent Number: 6,637,836

Title: Brake servo unit control device

Abstract: The solenoid current increases at low temperatures and decreases at hightemperatures because the modulus of elasticity of an elasticallydeformable valve body and the slide resistance of an elasticallydeformable seal member vary with temperatures. Therefore the solenoidcurrent for opening the valve mechanism from a closed position is requiredto be changed with low and high temperatures. To supply the solenoidcurrent necessary for opening the valve mechanism without directlymeasuring the temperature, the solenoid current (the boost startingcurrent leaning value) indicated when the pressure varies with the openingof the valve mechanism is recorded at the time of pressure-increasing, andthereafter when the valve mechanism is opened again after the closing ofthe valve mechanism, the solenoid current computed on the basis of thepressure-increase starting current learning value thus recorded issupplied.

Inventors: Kuragaki; Satoru (Hitachi, JP), Yoshikawa; Tokuji (Hitachi, JP), Yokoyama; Atsushi (Niihari, JP), Manaka; Toshio (Hitachinaka, JP)

Assignee:

International Classification: B60T 13/66 (20060101); B60T 8/36 (20060101); B60T 13/72 (20060101); B60T 8/48 (20060101); B60T 7/12 (20060101); B60T 008/44 (); B60T 007/12 (); B60T 013/52 (); B60T 013/66 (); B60T 013/72 ()

Expiration Date: 10/22015