| 摘要 |
<p>The present invention relates to a commercial brake system, which automatically controls the operation of a friction type brake and a retarder according to the vehicle speed when a driver puts on the brakes, and to a control method thereof. For the above-mentioned purpose, the commercial brake system comprises: a brake pedal, which receives a braking requirement made by the driver; a retarder operation valve, which supplies oil to a retarder through a heat exchanger according to opening and closing operations to operate the retarder; a brake operation valve, which operates an actuator according to opening and closing operations to operate the brake; and a main control unit. The main control unit determines operating time of the retarder and the brake according to the vehicle speed when there is the braking requirement made by the driver, opens a passage by applying an electrical signal to the retarder operation valve when the retarder starts to operate, and opens the brake operation valve by applying the electrical signal to the brake operation valve when the brake starts to operate. It is desirable that the main control unit operates only the retarder by opening the retarder operation valve when the vehicle speed is above a predetermined value at the time of the braking requirement made by the driver. Also, it is desirable that the main control unit operates only the brake by opening the brake operation valve when brake pedal pressure input by the driver through the brake pedal is above a predetermined value. Accordingly, the commercial brake system automatically determines operation time of the friction type brake and the retarder according to the vehicle speed when there is the braking requirement made by the driver and slows down the speed of the vehicle, using the retarder. Therefore, the replacement of a friction type brake pad can be delayed.</p> |
