Electro-hydraulic brake system including isolation valves

An electro-hydraulic brake system for a vehicle having a plurality of wheel brakes, the electro-hydraulic brake system comprising:

• a master cylinder block disposed in fluid communication with a reservoir tank containing a brake fluid;
• a manifold block disposed in fluid communication with said master cylinder block for supplying the brake fluid from said master cylinder block to the wheel brakes;
• said master cylinder block defining a bore extending along a side surface of said master cylinder block for receiving at least one brake piston and a pair of openings including a primary opening and a secondary opening, spaced apart from one another, in fluid communication with said bore;
• a protrusion extending outwardly from a rear surface of said master cylinder block to a terminal end;
• a pressure supply unit coupled to a front surface of said master cylinder block and in fluid communication with said reservoir tank for supplying the brake fluid from said reservoir tank;
• a master cylinder electronic control unit coupled to said rear surface of said master cylinder block and in an abutment relationship with said protrusion;
• and
• at least one isolation valve disposed on said rear surface, spaced apart from said protrusion and received by said master cylinder electronic control unit, for regulating brake fluid flow from said master cylinder block to the wheel brakes,
• wherein the electro-hydraulic brake system further includes a wheel speed sensor coupled to each of the wheel brakes and configured to measure wheel speed and communicating the wheel speed to said master cylinder electronic control unit,
• wherein, in response to a manifold block failure, said master cylinder electronic control unit determines percent slip based on the wheel speed received from said wheel speed sensor and, in response to said percent slip exceeding a predetermine threshold, said master cylinder electronic control unit selectively opens and closes said at least one isolation valve to permit brake fluid pressure supplied by said pressure supply unit to be reduced to said percent slip below said predetermined threshold.

A method of preventing wheel slip for a vehicle having a plurality of wheel brakes each having a wheel speed sensor using an electro-hydraulic brake system, the electro-hydraulic brake system includes a master cylinder block defining a bore and a pair of openings including a primary opening and a secondary opening in fluid communication with the bore, a manifold block in fluid communication with the master cylinder block, a pressure supply unit coupled the master cylinder block, a pair of isolation valves including a first isolation valve and a second isolation valve with the first isolation valve being located between the bore and the primary opening and the second isolation valve being located between the bore and the secondary opening, and a master cylinder electronic control unit connected to the wheel speed sensors, said method comprising the steps of:

• detecting a failure in the manifold block;
• determining percent slip for the wheels based on feedback received from the wheel speed sensors;
• and
• reducing the percent slip by selectively opening and closing the isolation valves or reducing brake fluid pressure supplied by the pressure supply unit.