Brake control device for a vehicle

A brake control device for a vehicle comprising:

• a master cylinder which generates a master cylinder hydraulic pressure in response to a depressing force applied to a brake pedal;
• a sensor which senses the master cylinder hydraulic pressure;
• a wheel cylinder connected with the master cylinder via a hydraulic conduit;
• a stroke simulator connected to a branch hydraulic conduit branching from the hydraulic conduit;
• a first solenoid valve disposed in the hydraulic conduit between the wheel cylinder and a point where the branch hydraulic conduit branches from the hydraulic conduit, the first solenoid valve alternatively permitting and preventing communication between the master cylinder and the wheel cylinder;
• a second solenoid valve disposed in the branch hydraulic conduit to alternatively permit and prevent communication between the master cylinder and the stroke simulator;
• a pressure controlling mechanism connected to the hydraulic circuit between the first solenoid valve and the wheel cylinder to produce hydraulic pressure, the pressure controlling mechanism including a pressure source;
• control means operatively connected to the pressure controlling mechanism, the first solenoid valve and the second solenoid valve to close the first solenoid valve, open the second solenoid valve and operate the pressure controlling mechanism to apply the hydraulic pressure produced by the pressure controlling mechanism to the wheel cylinder when the pressure controlling mechanism is in a normal condition and the master cylinder hydraulic pressure sensed by the sensor is less than a first predetermined pressure level, and to close the first solenoid valve, close the second solenoid valve and operate the pressure controlling mechanism to apply the hydraulic pressure produced by the pressure controlling mechanism to the wheel cylinder when the pressure controlling mechanism is in the normal condition and the master cylinder hydraulic pressure sensed by the sensor is greater than the predetermined level.

A method of controlling brake force in a vehicle comprising:

• generating a master cylinder hydraulic pressure in response to a depressing force applied to a brake pedal;
• sensing the master cylinder hydraulic pressure;
• controlling hydraulic pressure supplied to a wheel cylinder from a pressure controlling mechanism that includes a pressure source;
• introducing the master cylinder hydraulic pressure into a stroke simulator while hydraulic pressure is supplied to the wheel cylinder from the pressure controlling mechanism when the master cylinder hydraulic pressure is less than a predetermined value and the pressure controlling mechanism is in a normal condition;
• and
• preventing the master cylinder hydraulic pressure from being introduced into the stroke simulator while hydraulic pressure is supplied to the wheel cylinder from the pressure controlling mechanism when the master cylinder hydraulic pressure is greater than a predetermined value and the pressure controlling mechanism is in the normal condition.