Patent ID: 9037375
Filing Date: 2015-05-19
Classification: B60T

Abstract:
1. A vehicle brake system comprising: a brake operation unit for generating a braking force in response to a pressure applied by a user; a brake caliper operatively associated with a vehicle wheel for applying a braking force to said vehicle wheel; a hydraulic line for selectively interconnecting the brake operation unit and the brake caliper; a normally open regulator valve disposed in fluid communication with the hydraulic line and configured to hold hydraulic pressure in a portion of the hydraulic line extending between the regulator valve and the caliper when said regulator valve is closed; a control unit capable of determining whether a transmission is set in a driving mode or in a non-driving mode; and a booster unit for increasing an initial braking force generated when the brake operation unit is operated, the booster unit operable to increase an initial pressure level generated by the initial braking force in order to attain an enhanced pressure level; the vehicle brake system configured to selectively maintain said regulator valve in a closed configuration in order to operate a braking force holding function for holding the initial braking force, which is generated by operating the brake operation unit, in the portion of the hydraulic line extending between the regulator valve and the caliper; wherein the vehicle brake system is configured and arranged to operate such that: when the braking force is applied and a speed of the vehicle becomes lower than a predetermined speed threshold value, the control unit closes the regulator valve to operate the braking force holding function, and when the control unit operates the braking force holding function and determines that the transmission is set in the non-driving mode, the control unit increases the initial braking force, which is generated by operating the brake operation unit, by operating the booster unit to attain the enhanced pressure level and then holds the enhanced pressure level in the portion of said hydraulic line between the regulator valve and the caliper.