| 摘要 |
PURPOSE:To complete the air vent from a hydraulic brake system at a less expenditure of labor and time by providing three-port two-position solenoid change- over valve and an electric control circuit which actuates the valve for a specified period. CONSTITUTION:An air over hydraulic brake system 10 is provided with a compressed air supply system including a compressor 11 which is driven by an engine. When compressed air is supplied in the atmospheric chamber 16c of an air master cylinder 16, an air pressure piston 16a drives a hydraulic piston 16b to generate an oil pressure, by which wheel cylinders 17 are criven to give a control power of the brake device. If air is released from the hydraulic brake system 18, switches S1 and S2 are cloed and a three-port two-position change- over valve 21 is periodically actuated for a specified period by operating both a timer relay 22 and a solenoid relay 23. Compressed air from a port 21b may be periodically fed into the air pressure 16c and under such condition, air vent is executed. |
