How does the solenoid valve make the air pressure change from small to large

Solenoid valves cannot control air pressure. A proportional valve can be installed in front of the machine to supply low-pressure air some time ago. After the cylinder extends a certain distance, the proportional valve receives the electric signal and provides high-pressure compressed air. You can understand the proportional valve as a pressure regulating valve that can automatically adjust the pressure. As for the control of electric signal, it can be automatic time setting or photoelectric switch to detect the position of piston rod. Please ask the person who designed this electrical appliance.