| 摘要 |
PROBLEM TO BE SOLVED: To provide a product capable of holding brake hydraulic pressure with high reliability by performing the valve closing operation of a normal open solenoid value without using a large electromagnetic force when the temporarily holding brake hydraulic pressure of a wheel brake after releasing a braking operation, compactly forming a brake hydraulic pressure holding device and incorporating the wheel brake in even a large-size vehicle. SOLUTION: The normal open solenoid valve 2 is formed by providing a check valve 12 which is closed at the holding time of the brake hydraulic pressure and is normally opened by the energizing force of a valve opening energizing spring 38 at the non-holding time of the brake hydraulic pressure to enable the flow of the brake hydraulic pressure between a master cylinder and the wheel brake. In parallel with the check valve 12, a relief valve 50 opened when the brake hydraulic pressure of the wheel brake is higher than a set value to enable the return of the brake hydraulic pressure from the wheel brake to the master cylinder is provided. The valve closing operation of the check valve 12 offsets an energizing force in the valve opening direction of the check valve 12 by the valve opening energizing spring 38 by an electromagnetic force, and the check value 12 is closed by only the energizing force of a valve closing energizing force spring 32 operated by the offset. COPYRIGHT: (C)2004,JPO&NCIPI
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