| 摘要 |
<p>PURPOSE: To prevent the entry of oil to an exhaust tank by stopping the operation of a relay when a power supply to a motor is cut, so that a sliding valve makes communication between a common outlet and an inlet as long as a power supply is given to a coil and it makes communication between the common outlet and the inlet connected to an air once it is not given thereto. CONSTITUTION: A pump 15 works when a switch 21 is closed, while a coil 18 is supplied with power from a relay 33 and a sliding valve 17 makes communication between (a) and (c). As a result, the inner pressure of the void 7 of a valve 16 which is connected thereto via a duct 22 is suction pressure on the pump 15 and the valve 16 is left open. When power to the pump 15 is interrupted, the coil 18 is not supplied with power from the relay 13 and a reset spring for the sliding valve 17 makes communication between (b) and (c). The void 7 thus receives an atmospheric pressure or the pressure of a pressure gas via a filter 32, while the inside 24 of the valve 16 is at a low pressure, a flexible pipe 4 is compressed to assure automatic closing and the entry of oil into an exhaust tank 14 is prevented.</p> |
