When the punch is actually used, the pressure switch on the punch overload pump is turned ON (ON), so that the punch is in an operable state. Indicates that there is overload protection and can be stamped.

After the pump is started, due to the initial pressure, the main valve of the press overload oil pump moves slightly to the right.

When the oil pressure in the punching cylinder rises above the set pressure, the main valve moves to the right in the direction of the spring force, pushing the main valve seal to return the high pressure oil to the tank.

Turn off the pressure switch (OFF) to put the press in the stop alarm state.

When the system detects that the pressure exceeds the limit, use a solenoid valve to open the oil pressure line to relieve pressure. According to the electronic signal of the pressure sensor signal or the pressure monitor in the valve, the punching overload pump protection device is activated to lower the internal oil pressure, and the main valve seal is moved to the left by the spring force. The pressure switch is in the off state (OFF), so that the pressure continues to be in the stop pressure state.

At this point, the punch slider can be infused to the top dead center. After the overload is removed, the normal operation state of the punch can be restored by resetting the button.