The working principle of the permanent magnet chuck: the magnetic force line comes out from the N pole of the magnet, passes through the yoke, passes through the ferromagnetic workpiece, and then returns to the yoke to enter the S pole of the magnet. In this way, the permanent magnet chuck can firmly suck the workpiece on the working pole of the permanent magnet chuck. If the magnetic field line of the permanent magnet chuck is less than the working pole surface of the permanent magnet chuck, the closed circuit of the magnetic circuit is formed inside the permanent magnet chuck, and almost no magnetic field line comes out from the working pole surface of the permanent magnet chuck, so the workpiece will not produce suction, and it can be successfully unloaded.

1. Press the operating button of the grinding wheel motor to start the switch of the electric permanent magnet chuck. Note: the workpiece cannot be drawn, the contact of the relay is interlocked, and the grinding wheel motor cannot be started. 2, open the special distribution box of the machine tool, use the measuring pen to detect whether there is electricity at both ends of the fuse, and then use the multimeter 500V to measure the power supply voltage to 380V.