CN115647884A

CN115647884A - Electromagnetic clamping device and using method

Info

Publication number: CN115647884A
Application number: CN202211423451.7A
Authority: CN
Inventors: 张子骎
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2022-11-15
Filing date: 2022-11-15
Publication date: 2023-01-31
Anticipated expiration: 2042-11-15
Also published as: CN115647884B

Abstract

The invention provides an electromagnetic clamping device and a using method thereof. The device provided by the invention can eliminate the huge impact on the surface of the workpiece when the existing electromagnetic clamp is used for clamping, and protect the surface of the workpiece from being damaged; the device has the advantages of high automation level, simple operation, high flexibility of clamping workpieces, quick action response, constant clamping force and high efficiency, and is particularly suitable for clamping large-batch easily-deformed thin-wall parts.

Description

Electromagnetic clamping device and using method

Technical Field

The invention relates to electromagnetism and related technologies, in particular to a clamping device which utilizes electromagnetic force to clamp a workpiece quickly and has accurate and controllable clamping force, and particularly relates to an electromagnetic clamping device and a using method thereof.

Background

The machine tool clamp is a main component of process equipment and is widely applied to the field of mechanical manufacturing. The workpiece is clamped on the workbench of the machine tool, and the relative position relationship between the workpiece and the cutter and between the workpiece and the machine tool can be accurately determined, so that the machining precision of the part is ensured. When a workpiece is clamped by the traditional manual clamp, the labor intensity of workers is high, the clamping action is slow, the auxiliary processing time is long, the production efficiency is low, and the traditional manual clamp is increasingly difficult to meet the efficient production requirement of modern enterprises. At present, hydraulic or pneumatic clamps and other novel clamps are widely applied to enterprise production, and the machining automation level and the production efficiency are greatly improved. However, the hydraulic clamp and the pneumatic clamp have low transmission efficiency, complex structure, high manufacturing precision of components, difficult sealing, high requirement on maintenance personnel, more accessories, and the need of a special external power source for providing the action execution force for the components, the volume of a hydraulic station or an air compression station of the accessories is often large, and once a medium of the hydraulic clamp leaks, the environment is easily polluted. In the automatic and rapid clamping process, the clamp easily impacts the workpiece, the clamping force cannot be automatically adjusted along with the change of the size of the workpiece, and the clamp is difficult to be applied to clamping and processing of thin-wall workpieces.

Electromagnetic clamps have begun to find application in manufacturing, such as electromagnetic tables in surface grinding machines, electromagnetic chucks for adsorbing and transferring workpieces or palletizing workpieces, and the like. The electromagnetic clamp is mainly used for fixing a workpiece through suction force generated by the suction cup body after the electromagnetic coil is electrified, and the electromagnetic clamp is free of transmission medium and simple in structure. The adsorption efficiency that the circular telegram of electromagnetic clamp produced is powerful, and the electromagnetic adsorption efficiency that unit area produced is far greater than cutter cutting force, and is convenient with the clamp tight to the location of work piece, and the action is nimble, does not need loaded down with trivial details and laborious manual operation, and it is one of the prior development directions of modern anchor clamps. At present, an electromagnetic clamp mainly clamps a workpiece by means of 'electromagnetic attraction' generated by electrifying, a clamping object needs to be a magnetic material, a clamped large workpiece needs to have a flat plane, and the electromagnetic clamp cannot clamp the non-magnetic metal material or the non-metal material. Electromagnetic fixture is at the during operation, and the relative distance is different between work piece and the anchor clamps, and the work piece receives the electromagnetic force size different, and the work piece is more near apart from anchor clamps, and the electromagnetic force is big more, and when the distance is nearer, electromagnetic fixture produces very big adsorption affinity to the work piece, causes the work piece high-speed motion to be adsorbed on the anchor clamps with the striking mode, and the striking leads to the fact the damage to workpiece surface easily. For a workpiece with an easily deformed thin wall, the impact force at the moment of contact between the workpiece and the clamp is difficult to control effectively due to the inevitable error of the size of the workpiece in the machining process of the last procedure. The impact not only causes surface damage of the thin-wall part, but also causes deformation of local areas of the thin-wall part, and even directly causes product rejection. These deficiencies have all significantly limited the further use of electromagnetic clamps.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides an electromagnetic clamping device with accurately controllable clamping force and a using method thereof. The device comprises a quick moving system, a fine adjustment clamping system and a control system; the fast moving system comprises an upper platen 0101, a lower platen 0102, a left support plate 0201, a right support plate 0202, a first iron core 0301, a second iron core 0302, a third iron core 0303, a fourth iron core 0304, a first coil 0401, a second coil 0402, a third coil 0403, a fourth coil 0404, a left splint 0501, a left substrate 0701, a piston rod 17, a cylinder 18, an electric cabinet 20, a first pressure plate 2101 and a second pressure plate 2102; the first pressing plate 2101 is fixed on the upper platen 0101 by a screw, and the first pressing plate 2101 is installed above the rectangular guide rail of the left clamping plate 0501; the second pressing plate 2102 is fixed on the lower platen 0102 through screws, and the second pressing plate 2102 is installed above the rectangular guide rail of the left base plate 0701; the cylinder 18 is fixed on the lower platen 0102 through a screw, the piston rod 17 is installed in the cylinder 18, the left substrate 0701 is rigidly connected with the piston rod 17 through a screw, a guide rail below the left substrate 0701 is installed in a sliding groove of the lower platen 0102, the upper end of the left substrate 0701 penetrates through a slotted hole of the upper platen 0101, the upper end of the left substrate 0701 is rigidly connected with the left clamping plate 0501 through a screw, and a guide rail below the left clamping plate 0501 is installed in a sliding groove of the upper platen 0101; the right end of the first iron core 0301 penetrates through a through hole in the left substrate 0701, the first iron core 0301 is fixed on the left substrate 0701 through a screw, the first coil 0401 is installed on the first iron core 0301, the right end of the second iron core 0302 penetrates through the through hole in the left substrate 0701, the second iron core 0302 is fixed on the left substrate 0701 through a screw, the second coil 0402 is installed on the second iron core 0302, and the first coil 0401 is connected with the second coil 0402 in series; the other ends of the first coil 0401 and the second coil 0402 are respectively connected to a binding post of the electric cabinet 20, the left end of the third iron core 0303 passes through the through hole on the right supporting plate 0202, the third iron core 0303 is fixed on the right supporting plate 0202 through a screw, the third coil 0403 is installed on the third iron core 0303, the left end of the fourth iron core 0304 passes through the through hole on the right supporting plate 0202, the fourth iron core 0304 is fixed on the right supporting plate 0202 through a screw, the fourth coil 0404 is installed on the fourth iron core 0404, the third coil 0403 is connected with the fourth coil 0404 in series, and the other ends of the third coil 0403 and the fourth coil 0404 are respectively connected to the binding post of the electric cabinet 20; the left ends of the upper bedplate 0101 and the lower bedplate 0102 are fixedly connected with the left support plate 0201 through screws respectively, and the right ends of the upper bedplate 0101 and the lower bedplate 0102 are fixedly connected with the right support plate 0202 through screws respectively; the electric cabinet 20 is fixed below the lower bedplate 0102 through screws;

the fine-tuning clamping system comprises a right clamping plate 0502, a first stud 3201, a right base 0702, an end cover 08, a retainer ring 09, a tapered roller bearing 10, a screw rod 11, a coupling 12, an L-shaped bracket 13, a servo motor 14, a bushing 15, a supporting seat 16 and a first pressing plate 2101; the servo motor 14 is fixed on the L-shaped support 13 through a screw, the L-shaped support 13 and the support seat 16 are respectively fixed on the upper platen 0101 through a screw, the bushing 15 is screwed in a screw hole of the support seat 16 through a thread, and the left end face of the bushing 15 is fixed on the support seat 16; the screw rod 11 is installed on the bushing 15 through threaded connection; the inner ring of the tapered roller bearing 10 is installed on the outer circle of the left end of the lead screw 11, the outer ring of the tapered roller bearing 10 is installed in the stepped hole of the right base 0702, the retainer ring 09 is fixed on the outer circle of the left end of the lead screw 11 through screws, the left end step end face of the lead screw 11 and the right end face of the retainer ring 09 face the inner ring of the tapered roller bearing 10 to be axially fixed, the end cover 08 is fixed on the left step end face of the right base 0702 through screws, the right end face of the end cover 08 tightly presses the outer ring end face of the tapered roller bearing 10, the right end face of the end cover 08 and the stepped end face of the right base 0702 are axially fixed to the outer ring of the tapered roller bearing 10, the left end of the first double-head stud 3201 penetrates through hole of the right base 0702 to be installed in the screw hole of the right clamping plate 0502, the right end of the first double-head stud 3201 is fixedly connected with a nut, and the right clamping plate 0502 and the right base 0702 can move relatively. A guide rail below the right base 0702 is installed in a sliding groove of the upper platen 0101; the first pressing plate 2101 is installed above the right base 0702 rectangular guide rail, and the first pressing plate 2101 is fixed on the upper platen 0101 through a screw; the left end of the coupler 12 is connected with the right end of the screw rod 11 through a spline, and a middle hole in the right end of the coupler 12 is rigidly connected with an output shaft of the servo motor 14;

the control system comprises a travel switch 19, a pressure sensor 06, a U-shaped plate 23, a hard spring 25, a first adjusting nut 2601, a second adjusting nut 2602, a third adjusting nut 2603, a straight rod 27, a guide frame 28, a valve core 29, a valve sleeve 30, a hanger rail 31, a second stud 3202, a hook-shaped plate 22, a first stop pin 2401, a second stop pin 2402, a first spring pin 3301, a second spring pin 3302, a soft spring 34 and a control panel 35; the travel switch 19 is mounted on the lower platen 0102, the travel switch 19 is connected with the electric cabinet 20 through a wire, and the pressure sensor 06 is mounted in a stepped hole of the right base 0702; the valve sleeve 30 is connected with the cylinder 18 through a pipeline, and the valve sleeve 30 is fixed on the lower platen 0102 through a screw; the guide frame 28 is fixed on the lower platen 0102 by a screw, the right end of the straight rod 27 is in threaded connection with the valve core 29, a triangular throttling groove is formed in the valve core 29, the valve core 29 is installed in the valve sleeve 30, the left end of the straight rod 27 sequentially passes through a central hole of the guide frame 28, a screw hole of a third adjusting nut 2603, a through hole of a flange at the right end of the U-shaped plate 23, a screw hole of a second adjusting nut 2602, a screw hole of a first adjusting nut 2601 and a central hole of the hard spring 25, the first adjusting nut 2601, the second adjusting nut 2602 and the third adjusting nut 2603 are respectively in threaded connection with the straight rod 27, and the straight rod 27 is fixed on the U-shaped plate 23 by the second adjusting nut 2602 and the third adjusting nut 2603; the first stop pin 2401 and the second stop pin 2402 are installed on the lower platen 0102, the hanger rail 31 is fixed below the lower platen 0102 through screws, and the U-shaped plate 23 is installed below the hanger rail 31 through a dovetail groove; the first spring pin 3301 is installed on the hook plate 22, the second spring pin 3302 is installed on the U-shaped plate 23, one end of the soft spring 34 is installed on the first spring pin 3301, and the other end of the soft spring 34 is installed on the second spring pin 3302; one end of the second stud 3202 passes through the through hole of the hook plate 22 and then is fixed on the U-shaped plate 23 through threads, the other end of the second stud 3202 is fixedly connected with a nut, and the hook plate 22 can rotate around the second stud 3202; the hook plate 22, the first stop pin 2401, the second stop pin 2402, the hanger rail 31, the second stud 3202, the first spring pin 3301, the second spring pin 3302, and the soft spring 34 are symmetrically distributed on two sides of a center line of the U-shaped plate 23, the control panel 35 is fixed on the upper platen 0101 through a screw, and a lead of the control panel 35 is connected to a terminal of the electric cabinet 20.

The invention provides an electromagnetic clamping device, which comprises the following specific steps when in use:

1) When the clamping button on the control panel 35 is pressed, the power is turned on, the magnetic field generated by the energization of the first coil 0401 and the second coil 0402 has the same direction as the magnetic field generated by the energization of the third coil 0403 and the fourth coil 0404, and under the action of the electromagnetic attraction, the left substrate 0701 drives the left splint 0501 to move rapidly toward the right splint 0502 under the action of the first iron core 0301 and the second iron core 0302; the piston rod 17 is driven by the left substrate 0701 to move rightwards quickly;

2) The left substrate 0701 moves rightwards quickly for a certain distance and then contacts with the hard spring 25, and the left substrate 0701 pushes the hard spring 25, the straight rod 27 and the valve core 29 to move rightwards; after the left substrate 0701 drives the U-shaped plate 23 to move rightwards along the hanger rail 31 through the straight rod 27, and the U-shaped plate 23 drives the hook plate 22 to move rightwards for a certain distance, the hook plate 22 is separated from the first stopper pin 2401, and the hook plate 22 is in contact with the second stopper pin 2402; under the action of the second stop pin 2402, the hook plate 22 rotates, the valve core 29 is pushed by the straight rod 27 to gradually enter the valve sleeve 30, the flow area of a throttle valve port between the valve core 29 and the valve sleeve 30 is gradually reduced, the exhaust resistance of the right cavity of the air cylinder 18 is gradually increased, the rightward moving speed of the piston rod 17 is gradually reduced, the speeds of the left substrate 0701 and the left clamp 0501 are gradually reduced, the left clamp 0501 moves to be in contact with a workpiece after being decelerated, the left end of the hook plate 22 is clamped on the left end face of the left substrate 0701, and the travel switch 19 is pressed down by the left substrate 0701; the throttle channel on the valve core 29 is completely closed by the valve sleeve 30, the gas in the right cavity of the cylinder 18 cannot be exhausted, and the left base plate 0701 and the left clamping plate 0501 do not move rightwards any more;

3) After the travel switch 19 is pressed, the servo motor 14 is powered on to rotate, the servo motor 14 drives the lead screw 11 to rotate through the coupler 12, the lead screw 11 drives the right base 0203 and the right clamping plate 0502 to move leftwards, the right clamping plate 0502 gradually clamps the workpiece, the pressure between the right clamping plate 0502 and the workpiece is gradually increased, the pressure between the right clamping plate 0502 and the pressure sensor 06 is gradually increased, when the clamping force between the right clamping plate 0502 and the workpiece reaches a preset value, the pressure sensor 06 is triggered, the pressure sensor 06 feeds a pressure signal back to the electric cabinet 20, the electric cabinet 20 enables the servo motor 14 to be powered off to stop rotating, the right base 0200503 and the right clamping plate 0502 do not move leftwards any more, and the left clamping plate 0501 and the right clamping plate 2 complete clamping of the workpiece;

4) After the workpiece is machined, a release button on the control panel 35 is pressed, the servo motor 14 is energized with reverse current, the first coil 0401 and the second coil 0402 are energized with reverse current, magnetic fields generated by the first coil 0401 and the second coil 0402 are opposite to magnetic fields generated by the third coil 0403 and the fourth coil 0404, under the action of electromagnetic repulsion, the first iron core 0301 and the second iron core 0302 drive the left substrate 0701 and the left splint 0501 to move leftwards, the servo motor 14 is energized with reverse current to rotate reversely, the lead screw 11 rotates reversely and drives the right substrate 0203 and the right splint 0502 to move rightwards, the distance between the left splint 0501 and the right splint 0502 is gradually increased, and the workpiece is gradually released; after the left substrate 0701 moves a distance leftwards, the travel switch 19 returns to the original position, the servo motor 14 is powered off, and the right base 0203 and the right clamping plate 0502 stop moving; the left substrate 0701 continues to move leftwards under the action of electromagnetic force, the left substrate 0701 drives the U-shaped plate 23 to move leftwards through the hook plate 22, the U-shaped plate 23 drives the straight rod 27 and the valve core 29 to move leftwards, the relative position between the valve core 29 and the valve sleeve 30 is changed, the throttling channel on the valve core 29 is gradually opened, and the left moving speed of the left substrate 0701 and the left clamping plate 0501 is increased;

5) In the process that the left substrate 0701 moves leftwards, when the hook plate 22 is in contact with the first stop pin 2401, the hook plate 22 rotates under the action of the first stop pin 2401, the hook plate 22 is separated from the left end face of the left substrate 0701, the left substrate 0701 continues to move leftwards rapidly under the action of electromagnetic repulsion force and the return elastic force of the hard spring 25, and after the contact with the stop switch, the left substrate 0701 stops moving and resetting;

6) And when the workpiece needs to be clamped again and loosened, repeating the steps 1) to 5).

Compared with the prior art, the technical scheme has incomparable advantages:

1) The invention adopts electromagnetic force as a power source, and compared with a pneumatic or hydraulic clamp, the invention does not need auxiliary equipment or transmission medium, has simple structure, does not have the problem of medium leakage, and can clamp magnetic or non-magnetic workpieces.

2) Compared with the existing electromagnetic clamp, the electromagnetic clamp has the advantages that the clamping speed is controllable, the electromagnetic clamp has multiple speeds such as fast forward speed and slow forward speed, the dynamic feedback function is good, the auxiliary time is shortened, the extremely large impact force existing at the clamping moment of the common electromagnetic clamp is eliminated, and the surface of a workpiece is protected from being damaged.

3) The clamping force applied to the workpiece by the clamping device is accurate and controllable, the clamping force is constant, the clamping device is not influenced by the dimension machining error of the previous working procedure of the workpiece, the clamping device is suitable for clamping workpieces with different rigidity, and the clamping device not only can clamp thick-wall workpieces with high rigidity, but also can clamp thin-wall parts with low rigidity and easy variability.

4) The device has good guidance quality, accurate clamping position to the workpiece and good anti-overturning performance, the servo motor does not need to work for a long time, only needs to rotate forwards or backwards for a short time, effectively protects the expensive motor and prolongs the service life of the motor.

5) The clamping device has the advantages of small volume, compact structure, high automation degree of the clamping process, simple operation, good controllability, strong robustness, safe and reliable clamping and high working efficiency.

Drawings

FIG. 1 is an isometric view of an electromagnetic clamping device;

FIG. 2 is a front view of an electromagnetic clamping device;

FIG. 3 is a top view of an electromagnetic clamping device;

FIG. 4 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 3;

FIG. 5 is an enlarged view taken at I in FIG. 4;

FIG. 6 is a cross-sectional view taken along section B-B of FIG. 2;

FIG. 7 is a cross-sectional view taken along section C-C of FIG. 4;

FIG. 8 is an enlarged view taken at II in FIG. 7;

FIG. 9 is a bottom view of the apparatus of the present invention without clamping the workpiece (with the lower wire broken);

FIG. 10 is a bottom view of the apparatus of the present invention gripping a workpiece (with the lower wire broken);

fig. 11 is a schematic view of the shape of the U-shaped plate 23.

In the figure: 0101: an upper platen; 0102: a lower platen; 0201: a left support plate; 0202: a right support plate; 0301: a first iron core; 0302: a second core; 0303: a third iron core; 0304: a fourth iron core; 0401: a first coil; 0402: a second coil; 0403: a third coil; 0404: a fourth coil; 0501: a left splint; 0502: a right splint; 06: a pressure sensor; 0701: a left substrate; 0702: a right base; 08: an end cap; 09: a retainer ring; 10: a tapered roller bearing; 11: a screw rod; 12: a coupling; 13: an L-shaped bracket; 14: a servo motor; 15: a bushing; 16: a supporting seat; 17: a piston rod; 18: a cylinder; 19: a travel switch; 20: an electric cabinet; 2101: a first platen; 2102: a second platen; 22: a hook plate; 23: a U-shaped plate; 2401: a first stop pin; 2402: a second stop pin; 25: a stiff spring; 2601: a first adjusting nut; 2602: a second adjusting nut; 2603: a third adjusting nut; 27: a straight rod; 28: a guide frame; 29: a valve core; 30: a valve housing; 31: hoisting a rail; 3201: a first stud; 3202: a second stud; 3301: a first spring pin; 3302: a second spring pin; 34: a soft spring; 35: a control panel.

Detailed Description

The present invention provides an electromagnetic clamping device and method of use, the details of which are described in detail in conjunction with the accompanying figures 1-11.

The device comprises a fine adjustment clamping system, a quick moving system and a control system. The fast moving system comprises an upper platen 0101, a lower platen 0102, a left support plate 0201, a right support plate 0202, a first iron core 0301, a second iron core 0302, a third iron core 0303, a fourth iron core 0304, a first coil 0401, a second coil 0402, a third coil 0403, a fourth coil 0404, a left splint 0501, a left substrate 0701, a piston rod 17, an air cylinder 18, a first pressing plate 2101, a second pressing plate 2102 and an electric cabinet 20. The left ends of the upper platen 0101 and the lower platen 0102 are fixedly connected to the left support plate 0201 by screws, and the right ends thereof are fixedly connected to the right support plate 0202 by screws, and as shown in fig. 1, U-shaped grooves for mounting are provided in the bottom plates of the left support plate 0201 and the right support plate 0202 so as to mount the jig on the machine tool table. The cylinder 18 is fixed to the lower platen 0102 by a screw, the piston rod 17 is installed in the cylinder 18, and the piston on the piston rod 17 is slidable and airtight with the cylinder 18. The upper end of the left base plate 0701 penetrates through a slotted hole of the upper platen 0101 and then is rigidly connected with the left clamp plate 0501 through a screw, the middle part of the left base plate 0701 is fixedly connected with the left end of the piston rod 17 through a screw, a triangular guide rail and a rectangular guide rail below the left clamp plate 0501 are respectively installed in two sliding grooves of the upper platen 0101, and a triangular guide rail and a rectangular guide rail on the left side and the right side below the left base plate 0701 are installed in two sliding grooves of the lower platen 0102, as shown in fig. 7. The first pressing plate 2101 is fixed to the upper platen 0101 by screws above the rectangular rail of the left clamp plate 0501. The second pressing plate 2102 is fixed to the lower platen 0102 by screws and is located above the rectangular guide rail of the left base plate 0701. The surfaces of the guide rails on the left clamping plate 0501 and the left base plate 0701 and the sliding grooves of the upper platen 0101 and the lower platen 0102 are smooth, the resistance of the mutual movement of the guide rails and the sliding grooves is small, the phenomenon of stagnation is avoided, lubricating oil can be coated when the device is used, and the resistance between the guide rails and the sliding grooves is further reduced. Triangular guide rails are used on the left clamping plate 0501 and the left base plate 0701, when a workpiece is clamped, the left clamping plate 0501 can only move along a straight line, the precision and the guiding performance of the straight line movement of the guide rails are improved, the clamp can accurately clamp the position of the workpiece conveniently, the contact area of the rectangular guide rails is large, and the bearing capacity of the clamp is improved. The wear of the triangular guide rails can also be compensated automatically during use. The gap between the first pressing plate 2101 and the rectangular guide rail of the left clamping plate 0501 and the gap between the second pressing plate 2102 and the rectangular guide rail of the left base plate 0701 are adjusted, so that the resistance of the guide rail pair during movement is reduced, and the dynamic rigidity and the anti-overturning moment capacity of the clamp system are improved. The right end of the first iron core 0301 penetrates through the through hole in the left substrate 0701, the first iron core 0301 is fixed on the left substrate 0701 through a screw, the first coil 0401 is installed on the first iron core 0301, the right end of the second iron core 0302 penetrates through the through hole in the left substrate 0701, the second iron core 0302 is fixed on the left substrate 0701 through a screw, the second coil 0402 is installed on the second iron core 0302, and the first coil 0401 is connected with the second coil 0402 in series. The other ends of the first coil 0401 and the second coil 0402 are respectively connected to the binding post of the electric cabinet 20, as shown in fig. 6, the left end of the third core 0303 passes through the through hole on the right supporting plate 0202, the third core 0303 is fixed on the right supporting plate 0202 by a screw, the third coil 0403 is installed on the third core 0303, the left end of the fourth core 0304 passes through the through hole on the right supporting plate 0202, the fourth core 0304 is fixed on the right supporting plate 0202 by a screw, the fourth coil 0404 is installed on the fourth core 0404, the third coil 0403 is connected in series with the fourth coil 0404, the other ends of the third coil 0403 and the fourth coil 0404 are respectively connected to the binding post of the electric cabinet 20, and the electric cabinet 20 is fixed below the lower platen 0102 by a screw, as shown in fig. 2. The first iron core 0301 and the second iron core 0302 at the left end and the third iron core 0303 and the fourth iron core 0304 at the right end are symmetrically distributed, and the first coil 0401 and the second coil 0402 at the left end and the third coil 0403 and the fourth coil 0404 at the right end are also symmetrically distributed, as shown in fig. 6.

The fine-tuning clamping system comprises a right clamping plate 0502, a first double-ended stud 3201, a right base 0702, an end cover 08, a retainer ring 09, a tapered roller bearing 10, a screw rod 11, a coupling 12, an L-shaped bracket 13, a servo motor 14, a bushing 15, a supporting seat 16 and a first pressing plate 2101. The L-shaped bracket 13 and the supporting base 16 are both fixed to the upper platen 0101 by screws, and the left flange of the servo motor 14 is fixed to the L-shaped bracket 13 by screws. The bush 15 is installed in a screw hole of the support base 16 through threads, the left end face of the bush 15 is fixed on the support base 16 through a screw, and the center line of the output shaft of the servo motor 14 is equal in height and coaxial with the center line of the bush 15. The screw rod 11 is screwed on the bush 15 through threads. An inner ring of the tapered roller bearing 10 is mounted on an outer circle at the left end of the screw rod 11, an outer ring of the tapered roller bearing 10 is mounted in a stepped hole of the right base 0702, the retainer ring 09 is fixed on the outer circle at the left end of the screw rod 11 through screws, a stepped surface at the left end of the screw rod 11 and a right end surface of the retainer ring 09 are axially fixed on the inner ring of the tapered roller bearing 10, the end cover 08 is fixed on a left stepped end surface of the right base 0702 through screws, a right end surface of the end cover 08 presses an outer ring end surface of the tapered roller bearing 10, and a right end surface of the end cover 08 and a stepped end surface of the right base 0702 are axially fixed on the outer ring of the tapered roller bearing 10, as shown in fig. 5, the tapered roller bearing 10 can bear an axial force of a clamp when clamping a workpiece. The left end of the first stud 3201 penetrates through a through hole of the right base 0702 and is installed in a screw hole of the right clamping plate 0502, the right end of the first stud 3201 is fixedly connected with a nut, and a gap is reserved between the right clamping plate 0502 and the right base 0702, as shown in fig. 4. When clamping, the right clamping plate 0502 can slightly move rightwards, the gap between the right clamping plate 0502 and the right base 0702 is eliminated, the clamping force is transmitted to the pressure sensor 06 through the right clamping plate 0502, the assembly relation can prevent the poor contact between the workpiece with uneven surface and the sensor 6, and the accuracy of pressure measurement is improved. The guide rail below the right base 0702 is mounted in the chute of the upper platen 0101. The first pressing plate 2101 is fixed on the upper platen 0101 by screws and is located above the guide rail of the right base 0702 to improve the dynamic rigidity and the anti-overturning capability of the clamp. The left end of the coupler 12 is connected with the right end of the screw rod 11 in a spline fit mode, a middle hole in the right end of the coupler 12 is fixedly connected with an output shaft of the servo motor 14 through a screw, the coupler 12 is in spline fit with the screw rod 11, rotation and torque of the servo motor 14 are transmitted to the screw rod 11, the relative position of the screw rod 11 and the coupler 12 can be changed, the screw rod 11 can not only rotate, but also move axially, and the right clamping plate 0502 is driven to clamp and loosen a workpiece.

The control system comprises a travel switch 19, a pressure sensor 06, a U-shaped plate 23, a hard spring 25, a first adjusting nut 2601, a second adjusting nut 2602, a third adjusting nut 2603, a straight rod 27, a guide frame 28, a valve core 29, a valve sleeve 30, a hanger rail 31, a second stud 3202, a hook-shaped plate 22, a first stop pin 2401, a second stop pin 2402, a first spring pin 3301, a second spring pin 3302, a soft spring 34, a control panel 35 and the like. The travel switch 19 is installed on the lower platen 0102 through a screw, the travel switch 19 is connected with the electric cabinet 20 through a wire, and the pressure sensor 06 is installed in a stepped hole of the right base 0702 and is in close contact with the right end face of the right clamping plate 0502. The valve sleeve 30 is connected to the cylinder 18 through a pipeline, and the valve sleeve 30 is fixed to the lower platen 0102 through a screw. The guide frame 28 is fixed on the lower platen 0102 through a screw, the right end of the straight rod 27 is connected with the valve core 29 through a thread, a triangular throttling groove is formed in the valve core 29, the valve core 29 is installed in the valve sleeve 30, the relative position between the valve core 29 and the valve sleeve 30 can be changed, as shown in fig. 9 and 10, when an exhaust channel on the valve core 29 through a throttling opening is completely closed by the valve sleeve 30, good air tightness between the valve core 29 and the valve sleeve 30 is required, and gas in the valve sleeve 30 cannot be exhausted. The left end of the straight rod 27 sequentially passes through a central hole of the guide frame 28, a screw hole of the third adjusting nut 2603, a through hole on a flange at the right end of the U-shaped plate 23, a screw hole of the second adjusting nut 2602, a screw hole of the first adjusting nut 2601 and a central hole of the hard spring 25. The first adjusting nut 2601, the second adjusting nut 2602 and the third adjusting nut 2603 are respectively in threaded connection with the straight rod 27. The position relationship between the valve element 29 and the valve sleeve 30 and the sealing position of the throttle passage of the valve element 29 are adjusted by adjusting the position of the first adjusting nut 2601 to adjust the axial position of the hard spring 25 according to the size of the workpiece to be clamped. As shown in fig. 11, the second adjusting nut 2602 and the third adjusting nut 2603 are located on the left and right sides of the flange at the right end of the U-shaped plate 23, and they abut against the flange on the U-shaped plate 23 to fix the straight bar 27 and the U-shaped plate 23 together, so that the left base plate 0702 drives the U-shaped plate 23 to move when pushing the straight bar 27 to move to the right. The first stop pin 2401 and the second stop pin 2402 are installed on the lower bedplate 0102, a counter bore is formed in the hanger rail 31, a screw is installed in the counter bore to fix the hanger rail 31 below the lower bedplate 0102, the U-shaped plate 23 is installed below the hanger rail 31 through a dovetail groove, and the U-shaped plate 23 can slide on the hanger rail 31 and cannot fall off. One end of the second stud 3202 passes through the central hole of the hook plate 22 and then is fixed on the U-shaped plate 23 through threads, the other end of the second stud 3202 is fixedly connected with a nut, and the hook plate 22 can rotate around the second stud 3202. The first spring pin 3301 is installed on the hook plate 22, the second spring pin 3302 is installed on the U-shaped plate 23, one end of the soft spring 34 is installed on the first spring pin 3301, the other end of the soft spring 34 is installed on the second spring pin 3302, and the soft spring 34 ensures that the hook plate 22 is not dislocated due to the excessive rotation angle. The hook plate 22, the first pin 2401, the second pin 2402, the hanger rail 31, the second stud 3202, the first spring pin 3301, the second spring pin 3302, and the soft spring 34 are symmetrically distributed on two sides of the center line of the U-shaped plate 23. During the rightward movement of the cylinder 18, the exhaust gas is exhausted through the throttling port between the valve sleeve 30 and the valve core 29, the flow area of the throttling port on the valve core 29 is gradually reduced, the pressure of the right cavity of the cylinder 18 is gradually increased, the rigidity in the loop is gradually increased, the rapid movement of the piston rod 17 is blocked, and the speed of the left clamping plate 0501 is reduced. When the throttling port on the valve core 29 is completely closed by the valve sleeve 30 finally, the gas in the right cavity of the air cylinder 18 can not be discharged, the pressure in the right cavity of the air cylinder 18 is rapidly increased, the resistance of the piston rod 17 to move rightwards is rapidly increased, the left base plate 0702 and the left clamping plate 0501 do not move rightwards any more, and therefore severe collision between the left clamping plate 0501 and a workpiece to be clamped is avoided. When the first coil 0401, the second coil 0402, the third coil 0403 and the fourth coil 0404 are supplied with higher current, the higher the electromagnetic force is, the higher the speed of the left substrate 0702 pushing the straight rod 27 to move rightwards by the higher electromagnetic force is, the higher the speed of closing the throttling opening of the valve core 29 is, the higher the resistance of the piston rod 17 to move rightwards is, and the higher the resistance is, so that the speed of reducing the left splint 0501 by the resistance is, therefore, the clamp can still avoid violent collision between the left splint 0501 and the workpiece, and the clamp system has good dynamic feedback function and strong robustness.

When the electromagnetic clamping device is used, the specific operation steps are as follows:

1) When the clamp button on the control panel 35 is pressed, the power is turned on, the magnetic field generated by the energization of the first coil 0401 and the second coil 0402 has the same direction as the magnetic field generated by the energization of the third coil 0403 and the fourth coil 0404, the left substrate 0701 drives the left splint 0501 to move rapidly towards the right splint 0502 under the action of the first iron core 0301 and the second iron core 0302, and the piston rod 17 moves rapidly to the right under the drive of the left substrate 0701.

2) The left substrate 0701 moves rightwards for a certain distance and then contacts with the hard spring 25, and the left substrate 0701 pushes the hard spring 25, the straight rod 27 and the valve core 29 to move rightwards. After the left base plate 0701 drives the U-shaped plate 23 to move rightwards along the hanger rail 31 through the straight rod 27, and the U-shaped plate 23 drives the hook-shaped plate 22 to move rightwards for a certain distance, the hook-shaped plate 22 is separated from the first stop pin 2401, and the hook-shaped plate 22 is in contact with the second stop pin 2402. Under the action of the second stop pin 2402, the hook plate 22 rotates, the valve core 29 is pushed by the straight rod 27 to gradually enter the valve sleeve 30, the flow area of a throttling valve port between the valve core 29 and the valve sleeve 30 is gradually reduced, the exhaust resistance of the right cavity of the air cylinder 18 is gradually increased, the rightward moving speed of the piston rod 17 is gradually reduced, the speeds of the left substrate 0701 and the left clamp plate 0501 are gradually reduced, the left clamp plate 0501 is in contact with a workpiece after being reduced in speed, the left end of the hook plate 22 is clamped on the left end face of the left substrate 0701, the travel switch 19 is pressed by the left substrate 0701, the throttling channel on the valve core 29 is completely closed by the valve sleeve 30, gas in the right cavity of the air cylinder 18 cannot be exhausted, and the left substrate 0701 and the left clamp plate 0501 cannot move rightwards any more, as shown in fig. 9.

3) After the travel switch 19 is pressed down, the servo motor 14 is powered on to rotate, the servo motor 14 drives the lead screw 11 to rotate through the coupler 12, the lead screw 11 drives the right base 0203 and the right clamping plate 0502 to move leftwards, the right clamping plate 0502 gradually clamps the workpiece, the pressure between the right clamping plate 0502 and the workpiece is gradually increased, the pressure applied to the pressure sensor 06 is gradually increased, when the pressure between the right clamping plate 0502 and the workpiece reaches a preset value, the pressure sensor 06 is triggered, the pressure sensor 06 feeds a pressure signal back to the electric cabinet 20, the electric cabinet 20 enables the servo motor 14 to be powered off and stop rotating, the right base 0203 and the right clamping plate 0502 do not move leftwards any more, and the left clamping plate 0501 and the right clamping plate 0502 complete clamping the workpiece.

4) After the workpiece is machined, the release button on the control panel 35 is pressed, the servo motor 14 is energized with a reverse current, the first coil 0401 and the second coil 0402 are also energized with a reverse current, the current directions of the third coil 0403 and the fourth coil 0404 are kept unchanged, the magnetic fields generated by the first coil 0401 and the second coil 0402 are opposite to the magnetic fields generated by the third coil 0403 and the fourth coil 0404, and the first iron core 0301 and the second iron core 0302 drive the left substrate 0701 and the left splint 0501 to move leftward under the action of electromagnetic repulsion. The servo motor 14 rotates reversely after being electrified with reverse current, the screw rod 11 rotates reversely and drives the right base 0203 and the right clamping plate 0502 to move rightwards, the distance between the left clamping plate 0501 and the right clamping plate 0502 is gradually increased, and the workpiece is gradually loosened. After the left substrate 0701 moves a distance to the left, the pressed travel switch 19 returns to the original position, the servo motor 14 is powered off, and the right base 0203 and the right clamping plate 0502 stop moving. The left substrate 0701 continues to move leftwards under the action of electromagnetic force, the left substrate 0701 drives the U-shaped plate 23 to move leftwards through the hook plate 22, the U-shaped plate 23 drives the straight rod 27 and the valve core 29 to move leftwards, the relative position between the valve core 29 and the valve sleeve 30 is changed, the throttling channel on the valve core 29 is gradually opened, and the left moving speed of the left substrate 0701 and the left clamping plate 0501 is increased.

5) In the process that the left substrate 0701 moves leftwards, when the hook plate 22 is in contact with the first stop pin 2401, the hook plate 22 rotates under the action of the first stop pin 2401, the hook plate 22 is separated from the left end face of the left substrate 0701, the hard spring 25 is required to return to a state before being compressed, the left substrate 0701 continues to move leftwards rapidly under the action of electromagnetic repulsion force and the return elastic force of the hard spring 25, and after the stop switch is touched, the left substrate 0701 stops moving and resetting.

Claims

1. An electromagnetic clamping device, characterized by: the device comprises a quick moving system, a fine adjustment clamping system and a control system; the fast moving system comprises an upper platen (0101), a lower platen (0102), a left support plate (0201), a right support plate (0202), a first iron core (0301), a second iron core (0302), a third iron core (0303), a fourth iron core (0304), a first coil (0401), a second coil (0402), a third coil (0403), a fourth coil (0404), a left splint (0501), a left substrate (0701), a piston rod (17), a cylinder (18), an electric cabinet (20), a first pressing plate (2101) and a second pressing plate (2102); the first pressing plate (2101) is fixed on the upper platen (0101) through a screw, and the first pressing plate (2101) is installed above the rectangular guide rail of the left clamping plate (0501); the second pressing plate (2102) is fixed on the lower platen (0102) through screws, and the second pressing plate (2102) is installed above the rectangular guide rail of the left base plate (0701); the cylinder (18) is fixed on the lower platen (0102) through a screw, the piston rod (17) is installed in the cylinder (18), the left substrate (0701) is rigidly connected with the piston rod (17) through a screw, a guide rail below the left substrate (0701) is installed in a sliding groove of the lower platen (0102), the upper end of the left substrate (0701) penetrates through a slotted hole of the upper platen (0101), the upper end of the left substrate (0701) is rigidly connected with the left clamping plate (0501) through a screw, and a guide rail below the left clamping plate (0501) is installed in a sliding groove of the upper platen (0101); the right end of the first iron core (0301) penetrates through a through hole in the left substrate (0701), the first iron core (0301) is fixed on the left substrate (0701) through a screw, the first coil (0401) is installed on the first iron core (0301), the right end of the second iron core (0302) penetrates through the through hole in the left substrate (0701), the second iron core (0302) is fixed on the left substrate (0701) through a screw, the second coil (0402) is installed on the second iron core (0302), and the first coil (0401) and the second coil (0402) are connected in series; the other ends of the first coil (0401) and the second coil (0402) are respectively connected to the electric cabinet (20), the left end of the third core (0303) passes through the through hole on the right supporting plate (0202), the third core (0303) is fixed on the right supporting plate (0202) by a screw, the third coil (0403) is mounted on the third core (0303), the left end of the fourth core (0304) passes through the through hole on the right supporting plate (0202), the fourth core (0304) is fixed on the right supporting plate (0202) by a screw, the fourth coil (0404) is mounted on the fourth core (0304), the third coil (0403) is connected in series with the fourth coil (0404), and the other ends of the third coil (0403) and the fourth coil (0404) are respectively connected to the electric cabinet (20); the left ends of the upper bedplate (0101) and the lower bedplate (0102) are fixedly connected with the left supporting plate (0201) through screws respectively, and the right ends of the upper bedplate (0101) and the lower bedplate (0102) are fixedly connected with the right supporting plate (0202) through screws respectively; the electric cabinet (20) is fixed below the lower bedplate (0102) through screws;

the fine-tuning clamping system comprises a right clamping plate (0502), a first double-ended stud (3201), a right base (0702), an end cover (08), a retainer ring (09), a tapered roller bearing (10), a screw rod (11), a coupling (12), an L-shaped bracket (13), a servo motor (14), a bushing (15), a supporting seat (16) and a first pressing plate (2101); the servo motor (14) is fixed on the L-shaped support (13) through screws, the L-shaped support (13) and the support seat (16) are respectively fixed on the upper bedplate (0101) through screws, the bushing (15) is screwed in a screw hole of the support seat (16) through threads, and the bushing (15) is fixed on the left end face of the support seat (16) through screws; the screw rod (11) is installed on the bushing (15) through threaded connection; the inner ring of the tapered roller bearing (10) is installed on the outer circle of the left end of the screw rod (11), the outer circle of the tapered roller bearing (10) is installed in the stepped hole of the right base (0702), the retainer ring (09) is fixed on the outer circle of the left end of the screw rod (11) through screws, the left end step end face of the screw rod (11) and the right end face of the retainer ring (09) face the inner ring of the tapered roller bearing (10) to be axially fixed, the end cover (08) is fixed on the left stepped end face of the right base (0702) through screws, the right end face of the end cover (08) is tightly pressed on the outer circle end face of the tapered roller bearing (10), the right end face of the end cover (08) and the stepped end face of the right base (0702) are opposite to the outer circle axially fixed of the tapered roller bearing (0702), the left end of the first double-head stud (3201) penetrates through hole of the right base (0702) to be installed in the screw hole of the right clamping plate (0502), the right double-head stud (3201) is fixedly connected with the right clamping plate (0502), and the right clamping plate (0502) and the right clamping plate (0702) can move relatively. A guide rail below the right base (0702) is arranged in a sliding groove of the upper platen (0101); the first pressing plate (2101) is arranged above the rectangular guide rail of the right base (0702); the left end of the coupler (12) is connected with the right end of the screw rod (11) through a spline, and a middle hole in the right end of the coupler (12) is rigidly connected with an output shaft of the servo motor (14);

the control system comprises a pressure sensor (06), a travel switch (19), a hook plate (22), a U-shaped plate (23), a first stop pin (2401), a second stop pin (2402), a hard spring (25), a first adjusting nut (2601), a second adjusting nut (2602), a third adjusting nut (2603), a straight rod (27), a guide frame (28), a valve core (29), a valve sleeve (30), a hanger rail (31), a second stud (3202), a first spring pin (3301), a second spring pin (3302), a soft spring (34) and a control panel (35); the travel switch (19) is mounted on the lower platen (0102), the travel switch (19) is connected with the electric cabinet (20) through a lead, and the pressure sensor (06) is mounted in a stepped hole of the right base (0702); the valve sleeve (30) is connected with the cylinder (18) through a pipeline, and the valve sleeve (30) is fixed on the lower platen (0102) through a screw; the guide frame (28) is fixed on the lower platen (0102) through a screw, the right end of the straight rod (27) is in threaded connection with the valve core (29), a triangular throttling groove is formed in the valve core (29), the valve core (29) is installed in the valve sleeve (30), the left end of the straight rod (27) sequentially penetrates through a middle hole of the guide frame (28), a screw hole of a third adjusting nut (2603), a through hole of the right end of the U-shaped plate (23), a screw hole of a second adjusting nut (2602), a screw hole of a first adjusting nut (2601) and a middle hole of the hard spring (25), the first adjusting nut (2601), the second adjusting nut (2602) and the third adjusting nut (2603) are respectively in threaded connection with the straight rod (27), and the straight rod (27) is fixed on the U-shaped plate (23) through the second adjusting nut (2602) and the third adjusting nut (2603); the first blocking pin (2401) and the second blocking pin (2402) are installed on the lower bedplate (0102), the hanger rail (31) is fixed below the lower bedplate (0102) through screws, and the U-shaped plate (23) is installed below the hanger rail (31) through a dovetail groove; the first spring pin (3301) is installed on the hook plate (22), the second spring pin (3302) is installed on the U-shaped plate (23), one end of the soft spring (34) is installed on the first spring pin (3301), and the other end of the soft spring (34) is installed on the second spring pin (3302); one end of the second stud bolt (3202) penetrates through the through hole of the hook plate (22) and then is mounted on the U-shaped plate (23) through threads, the other end of the second stud bolt (3202) is fixedly connected with a nut, and the hook plate (22) can rotate around the second stud bolt (3202); the hook plate (22), the first stop pin (2401), the second stop pin (2402), the hanger rail (31), the second stud (3202), the first spring pin (3301), the second spring pin (3302) and the soft spring (34) are symmetrically distributed on two sides of the center line of the U-shaped plate (23), the control panel (35) is fixed on the upper bedplate (0101) through screws, and a lead of the control panel (35) is connected to the electric cabinet (20).

2. An electromagnetic clamping device as defined in claim 1, wherein: the specific operation steps when the device is used are as follows:

1) a clamping button on the control panel (35) is pressed, the power supply is switched on, the direction of a magnetic field generated by electrifying the first coil (0401) and the second coil (0402) is the same as that of a magnetic field generated by electrifying the third coil (0403) and the fourth coil (0404), and under the action of electromagnetic attraction, the left substrate (0701) drives the left splint (0501) to rapidly move towards the right splint (0502) under the action of the first iron core (0301) and the second iron core (0302); the piston rod (17) is driven by the left substrate (0701) to move rightwards quickly;

2) The left substrate (0701) moves rightwards for a distance and then contacts with the hard spring (25), and the left substrate (0701) pushes the hard spring (25), the straight rod (27) and the valve core (29) to move rightwards; the left substrate (0701) drives the U-shaped plate (23) to move rightwards along the hanger rail (31) through the hard spring (25) and the straight rod (27), after the U-shaped plate (23) drives the hook-shaped plate (22) to move rightwards for a certain distance, the hook-shaped plate (22) is separated from the first stop pin (2401), and the hook-shaped plate (22) is in contact with the second stop pin (2402); under the action of the second stop pin (2402), the hook plate (22) rotates, the valve core (29) is pushed by the straight rod (27) to gradually enter the valve sleeve (30), the flow area of a throttling valve port between the valve core (29) and the valve sleeve (30) is gradually reduced, the exhaust resistance of the right cavity of the air cylinder (18) is gradually increased, the moving speed of the piston rod (17) to the right is gradually reduced, the speeds of the left base plate (0701) and the left clamp plate (0501) are gradually reduced, the left clamp plate (0501) is in contact with a workpiece after speed reduction, the left end of the hook plate (22) is clamped on the left end face of the left base plate (0701), the travel switch (19) is pressed down by the left base plate (0701), a throttling channel on the valve core (29) is completely closed by the valve sleeve (30), gas in the right cavity of the air cylinder (18) cannot be exhausted, and the left base plate (0701) and the left clamp plate (0701) cannot move rightwards any more;

3) After the travel switch (19) is pressed down, the servo motor (14) is electrified and rotated, the servo motor (14) drives the screw rod (11) to rotate through the coupler (12), the screw rod (11) drives the right base (0203) and the right clamping plate (0502) to move leftwards, the right clamping plate (0502) gradually clamps a workpiece, the pressure between the right clamping plate (0502) and the workpiece is gradually increased, the pressure applied to the right clamping plate (0502) is transmitted to the pressure sensor (06), when the clamping force between the right clamping plate (0502) and the workpiece reaches a preset value, the pressure sensor (06) is triggered, the pressure sensor (06) feeds a pressure signal back to the electric cabinet (20), the electric cabinet (20) enables the servo motor (14) to be powered off and stopped rotating, the right base (0203) and the right clamping plate (0502) do not move leftwards any more, and the left clamping plate (0501) and the right clamping plate (0502) complete clamping of the workpiece;

4) After the workpiece is processed, a release button on the control panel (35) is pressed, the servo motor (14) is electrified with reverse current, the first coil (0401) and the second coil (0402) are electrified with reverse current, magnetic fields generated by the first coil (0401) and the second coil (0402) are opposite to magnetic fields generated by the third coil (0403) and the fourth coil (0404) in direction, under the action of electromagnetic repulsion, the first iron core (0301) and the second iron core (0302) drive the left substrate (0701) and the left splint (0501) to move leftwards, the servo motor (14) is electrified to rotate reversely, the lead screw (11) rotates reversely and drives the right substrate (0203) and the right splint (0502) to move rightwards, the distance between the left splint (0501) and the right splint (0502) is gradually increased, the workpiece is gradually released, after the left substrate (0701) moves leftwards for a distance, the stroke switch (19) returns to the original position, and the servo motor (0203) stops moving right splint (0502); the left substrate (0701) continues to move leftwards under the action of electromagnetic repulsion force, the left substrate (0701) drives the U-shaped plate (23) to move leftwards through the hook plate (22), the U-shaped plate (23) drives the straight rod (27) and the valve core (29) to move leftwards, the relative position between the valve core (29) and the valve sleeve (30) is changed, a throttling channel on the valve core (29) is gradually opened, and the left substrate (0701) and the left clamping plate (0501) move leftwards at an increased speed;

5) In the process that the left substrate (0701) moves leftwards, when the hook plate (22) is in contact with the first stop pin (2401), the hook plate (22) rotates under the action of the first stop pin (2401), the hook plate (22) is separated from the left end face of the left substrate (0701), and the left substrate (0701) continues to move leftwards to be rapidly reset under the action of electromagnetic repulsion force and the restoring force of the hard spring (25);