Trigger Valve

To ensure that when the compressor is started, the vanes move out smoothly under all conditions, and minimize the noise that will be produced when the vanes strike the cylinder at the time, a mechanism combining the low pressure side check valve and high pressure side trigger valve has been adopted. When the vehicle is parked for a long period in the middle of summer for example, the suction side pressure may be slightly higher than the discharge side pressure. When the compressor is started under such a condition, the low pressure side check valve introduces the low pressure side gas to the back plane of vane, thereby causing the vane to move out, When the compressor starts compression, the check valve is closed by the vane back pressure.

When the balance pressure or discharge side pressure is slightly higher, the high pressure side trigger valve, immediately after the compressor has been started, introduces the high pressure side pressure to the back plane of vane, thereby causing the vane to move out.

When the compressor normally starts compression and causes the discharge pressure to rise, the trigger valve closes.

1. When compressor is stopped
The pressure in the compressor is maintained constant, as the valves are kept in the opened state by springs.




2. When compressor is restarted
When the compressor resumes rotation, the high pressure side trigger valve is placed in the opened state, thereby applying the high pressure side pressure directly to the back plane of vane to cause the vane to move out.




3. When compressor is in regular operation
When the high pressure side pressure rises to the extent that it overcomes spring action, the valve closes, and the centrifugal force causes the vane to move out.