Patent ID: 9174616
Filing Date: 2015-11-03
Classification: B60T

Abstract:
1. A method of operating a brake system comprising: providing a hydraulic dual-circuit brake control that includes a master brake cylinder with a brake pedal that communicates with the master brake cylinder, at least one pump for generating brake fluid pressure in the hydraulic pressure in the hydraulic dual-circuit brake control, at least one non-driven wheel brake with an inlet valve disposed in an inlet line having a spring-actuated open position and an electromagnetically switchable blocking position; providing an outlet valve with a spring actuated blocking position and an electromagnetically switchable open position, wherein the outlet valve is located in a return line leading back to the at least one pump; providing a shut-off valve connected between the pump, brake master cylinder, and the inlet valve, wherein the shut-off valve also has a spring actuated open position and an electromagnetically switchable blocking position; depressing the brake pedal and initiating a wheel hold mode in an ECU (Electronic Control Unit) for the brake system; applying pressure to the at least one non-driven wheel brake; accumulating pressure at the at least one non-driven wheel brake and maintaining the pressure by moving the inlet valve to the closed position, moving the shut-off valve to the blocking position that will modulate and maintain pressure buildup in the brake system downstream of the shut-off valve; maintaining wheel brake pressure at the at least one non-driven wheel brake; independent of application of the brake pedal; and releasing the wheel brake pressure at the at least one non-driven wheel brake when a release trigger event occurs, wherein the release trigger event is one of: an automatic trigger event and a driver actuated trigger event, wherein the step of releasing the wheel brake pressure includes actuating the outlet valve to move the outlet valve to the open position so that the accumulating pressure is reduced by moving the pressure through the return line.