Device and method for rotary closing of magnetic circuit part of contactor

The invention discloses a device and a method for rotary closing of a magnetic circuit part of a contactor, which are characterized in that an upper die part comprises a bearing seat (22), a pre-pressing shaft (1) is arranged in the bearing seat (22), the pre-pressing shaft (1) is connected with the bearing seat (22) through a bearing (3), an elastic pre-pressing block (4) is connected below the pre-pressing shaft (1), a first pin (5) is arranged below the bearing seat (22), and a small-diameter ball bearing (7) is arranged on the first pin (5); the lower die part comprises a bottom plate (10), a positioning mandrel (13) is arranged in the middle of the bottom plate (10), a left clamping block (14), a right clamping block (16), a cam handle (17) and a stop pin (18) are arranged on the bottom plate (10), and pressing blocks (11) are further arranged on the two sides of the bottom plate (10). Under the condition that the equipment pressure is limited, the magnetic circuit part with the wall thickness larger tha