| 摘要 |
PROBLEM TO BE SOLVED: To reduce the consumption of electric energy in a normally open pressure reduction control valve provided between a brake cylinder and a reservoir. SOLUTION: In the case of boosting a hydraulic pressure in a brake cylinder, it is required to maintain a hydraulic pressure reduction linear valve 62 in a closed condition. In the linear valve 62, a differential pressure reaction force is effected being caused by an electromagnetic drive force depending upon a supply current and a hydraulic pressure in a reservoir. If the electromagnetic drive force is larger than the differential pressure action force, it is held in a closed condition. In this case, not a maximum current is fed but a current with which the electromagnetic force is higher than the sum of the differential pressure action force and a marginal value. As a result, it is possible to decrease the consumption of electric energy for holding the closed condition.
|
