Answer: (1)Piston intake valve. The piston in the intake valve moves up and down to control the empty and loaded operation of the air compressor. When the air compressor is started, stopped and unloaded, the discharge solenoid valve uses the air inlet to supply air to the piston, causing the piston to close upward; when the air compressor is working at full load, the discharge solenoid valve is energized to stop discharging, the piston chamber is discharged from the exhaust port, the intake valve piston drops due to the intake pressure difference, the intake valve is fully opened, and the air compressor works at full load; when the pressure reaches the set pressure upper limit, the discharge solenoid valve loses power and starts to discharge, and pushes the intake valve piston up, so that the intake valve is in a closed state, and the air compressor is in an unloaded state.
The structure of the piston intake valve consists of an intake port, a valve cover, a piston, a base, and a discharge solenoid valve. The structure of the piston intake valve is shown in Figure 3-6.
(2) Butterfly intake control valve. When the air compressor is started, the valve plate of the intake valve is in a closed state to ensure that it is started without load. When the motor is running under heavy load, the three-phase solenoid valve is opened after power is applied, and the gas from it enters the servo cylinder of the intake valve, pushes the valve stem of the servo cylinder, drives the intake butterfly valve, makes it fully open, and starts heavy load operation. The single swing check valve inside the butterfly intake control valve has its own counterweight and fluororubber sealing ring. When the compressor main engine inhales air when starting, the check valve opens quickly due to the pressure difference; when the compressor is shut down, after the pressure difference is lost, the check valve can be closed quickly and tightly under the control of the counterweight to ensure that there is no oil spitting when the compressor is shut down. The opening and closing of the butterfly valve is controlled by the control cylinder. According to the received pressure signal, the piston rod of the cylinder can be controlled to extend for a certain length, and the butterfly valve can be opened or closed, thereby adjusting the intake volume of the compressor.
The structure of the butterfly intake control valve consists of a valve body, a single swing check valve, a butterfly valve, and a servo cylinder. The structure of the butterfly intake control valve is shown in Figure 3-7.
Figure 3-6 Piston-type intake valve structure Figure 3-7 Butterfly-type intake control valve structure
