| 摘要 |
PURPOSE:To hinder a bush rod from moving in its full stroke in the event of any abnormality by furnishing a three-way solenoid valve, which is to lead the same neg. pressure as that in a power diaphragm chamber to a leak chamber on the basis of signals given from a neg. pressure switch and a water temp. switch. CONSTITUTION:A neg. pressure switch 38 senses the pressure in a power diaphragm chamber 3, while a water temp. switch 40 does the temp. of the coolant for engine. If the neg. pressure and water temp. are over their respective specified values, a three-way solenoid valve 32 blocks the B1 port on the hose 15 side for atmospheric leakage so as to change over into the state in which the B2 port is in communication with A port. Then the neg. pressure in the above-mentioned power diaphragm chamber 3 is introduced into a leak chamber 5 via three-way connector 35, three-way solenoid valve 32 and hose 31 so as to bring the power diaphragm chamber 3 and leak chamber 5 to the same pressure. This hinders a bush rod 6 from moving its stroke to provide well secured safety. |
