Apparatus and method for isolating an intact portion of a service braking circuit from a failed service brake wheel end

摘要

An apparatus and method for protecting an intact portion of a service brake system from a failed wheel end of a vehicle is provided. A failure in a wheel end is detected by determining an operation state of each of the wheel ends by monitoring parameters including the pressure in a parking brake air supply line. When it is determined that a failed wheel end is present in the service brake system, an antilock braking modulator or a service brake isolation valve is switched to a state in which the failed wheel end is isolated from the rest of the brake system. The service brake of the failed wheel end is disabled, while the service brakes of the other wheel ends are enabled for normal operation including antilock braking. And the parking brake of the failed wheel end is enabled, while the parking brakes of the other wheel ends are disabled to prevent immobilization of the vehicle.

主权项

1. An apparatus for protecting an intact portion of a service brake system from a failed wheel end of a vehicle having at least two wheel ends, comprising:
a spring brake actuator provided for each of the wheel ends for actuating a service brake and releasing a spring applied parking brake; a spring brake control valve for controlling actuation of the spring brake actuator for parking braking; a differential protection valve provided for each of the wheel ends for controlling a first supply of fluid to the spring brake actuator for releasing the spring applied parking brake; a relay valve for applying and releasing the service brake via the spring brake actuator; an antilock braking modulator provided for each of the wheel ends for controlling a second supply of fluid to the spring brake actuator for service braking; and an antilock braking system control unit for determining an operation state of each of the wheel ends and controlling the antilock braking modulators of each of the wheel ends, individually, based upon detection of a failed operation state; wherein, when the operation state of a first wheel end of the at least two wheel ends is a fault state, the differential protection valve protects an intact wheel end service brake by preventing the parking brake of each wheel end of the at least two wheel ends that is in a normal operation state from automatically applying.