| 摘要 |
A pilot operated pilot valve which is adapted to employ a low wattage solenoid for operation of the pilot valve which functions as an amplifier to control or drive various types of larger air valves, such as a four-way valve, a three-way valve, a two-way valve and the like. The pilot valve includes a valve body with an inlet port, an exhaust port, and a cylinder port for directing pilot air to a valve to be controlled. A poppet spool valve is mounted in the valve body to control the flow of air between said ports. The poppet spool valve is biased to an inoperative position, by a return spring and by a pilot air assist return action, so as to block flow between the inlet port and the cylinder port but allow flow between the cylinder port and the exhaust port. A low wattage solenoid blocks an exhaust passageway system when it is de-energized to allow the return spring and pilot air to hold the poppet valve in an inoperative position. When the low wattage solenoid is energized, the last mentioned exhaust passageway system is closed and pilot air is then allowed to flow through an orifice in the top of the poppet spool valve into a chamber above the poppet spool valve and react against the effective top end area thereof, and move the poppet spool valve to an operative position to open a passageway between the inlet port and the cylinder port and block off any flow to the exhaust port.
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