The solenoid valve controls the action of the cylinder. Why does the throttle valve on the cylinder break, resulting in the air leakage sound of the solenoid valve SMC muffler? What is the principle?

The solenoid valve described by the landlord is a five-way solenoid valve. The muffler is connected to the exhaust port, that is, the gas exhaust port of the cylinder. As mentioned in the title, if the intake throttle valve is damaged, the throttle valve will not slow down the flow during the return of the piston rod, and the corresponding phenomena are rapid exhaust, increased sound at the muffler and rapid return of the cylinder.