| 摘要 |
PROBLEM TO BE SOLVED: To provide a brake system which suppresses a work time of a pump of a hydraulic control actuator to the minimum, and can secure a brake force which is necessary at the shortage of negative pressure by an inexpensive constitution without causing heavy weight.SOLUTION: It is determined whether or not a detected road face gradient exceeds a threshold which needs assistance by a VSC actuator 6 on the basis of detected negative pressure by a negative pressure detection sensor 11, detected hydraulic pressure by a hydraulic sensor 13, and the detected road face gradient by a G sensor 12, and when it is determined that the gradient exceeds the threshold, a pump is driven by the VSC actuator 6, and an auxiliary brake force is generated. Therefore, even if brake negative pressure is lacked, the pump of the VSC actuator 6 is driven only when needed, a work time of the pump can be thereby suppressed to the minimum, and the inexpensive pump can be used without causing the heavy weight of the pump as in a prior art.SELECTED DRAWING: Figure 2 |
