Numerically-controlled machine tool spindle detection device

Abstract

The utility model relates to the technical field of numerical control machine tools, in particular to a spindle detection device of a numerical control machine tool. Comprising a supporting table and further comprises moving plates which are symmetrically arranged on the upper surface of the supporting table, and fixing plates are fixedly connected to the upper surfaces of the two moving plates. The distance between the two movable plates can be effectively adjusted according to the specifications of spindles through the adjusting assembly, so that the spindles of different specifications can be effectively fixed through the fixing assembly, the spindles can be effectively fixed and clamped through the fixing assembly, and the spindle fixing device is simple in structure, convenient to use and high in practicability. The horizontal position of the dial indicator can be effectively adjusted through the arranged moving assembly, so that the detection effect of the dial indicator on the main shaft is improved, and the dial indicator can be conveniently disassembled, replaced and overhauled by a worker through the arranged mounting assembly; and the overall practicability of the device is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of numerical control machine tools, and more specifically, to a spindle detection device for a numerical control machine tool. Background Art

[0002] A numerical control machine tool, abbreviated as a CNC machine tool, is an automated machine tool equipped with a program control system. The control system can logically process a program with control codes or other symbolic instructions, decode it, represent it in coded numbers, input it into the numerical control device through an information carrier, and after arithmetic processing, the numerical control device issues various control signals to control the actions of the machine tool, and automatically processes parts according to the shape and size required by the drawing. When detecting the spindle of a numerical control machine tool, a spindle detection device for a numerical control machine tool is required.

[0003] In the prior art, the dial indicator of the detection device is generally integrated with the device. Since the dial indicator is a relatively precise part, when using the dial indicator, it is necessary to regularly disassemble and overhaul the dial indicator to ensure its accuracy. However, the detection devices in the prior art cannot conveniently and effectively disassemble, replace and overhaul the dial indicator. This will cause the dial indicator to be damaged after long-term use, resulting in the dial indicator being unable to effectively detect the spindle, thus affecting the detection result of the spindle, leading to a large error in the spindle detection result, affecting the subsequent normal use effect of the spindle, and at the same time reducing the overall practicality of the detection device.

[0004] Comparing with the Chinese patent with the publication number of CN220348229U, the utility model provides a spindle detection device for a numerical control machine tool, which relates to the technical field of numerical control machine tools and includes an overall structure and a detection component. The outer surface of the detection component is fixedly connected to the outer surfaces on both sides of the overall structure. The overall structure includes a bottom plate, and sliding grooves are formed at the front and rear positions on the top of the bottom plate. In the utility model, through the mutual cooperation of the cylinder, the damper, the compression spring, the limiting member and the connecting member, when the limiting member limits the spindle, the limiting member will slide in the cylinder. Since the shape of the limiting member is semi-circular, it can limit spindles of different sizes. And when the limiting member slides in the cylinder, the damper and the compression spring will feel the extrusion force, thus changing their own states. Then the limiting member can utilize the expansion force of the compression spring to more powerfully limit the spindle, ensuring that the spindle can always be stably located on the connecting member.

[0005] The above scheme can very conveniently detect and process spindles of different specifications, but the micrometer in the above scheme is still fixed to the entire device. When the micrometer is damaged, the staff still cannot easily and effectively disassemble, replace and repair the micrometer, and fails to solve the problems raised in the above background technology.

[0006] Therefore, those skilled in the art provide a CNC machine tool spindle detection device to solve the problems raised in the above background technology. Utility Model Content

[0007] The utility model aims to provide a CNC machine tool spindle detection device, comprising a support platform, and also comprising:

[0008] The movable plates are symmetrically arranged on the upper surface of the support platform, the upper surfaces of the two movable plates are fixedly connected with fixed plates, the opposite sides of the two fixed plates are rotatably connected with rotating rods, and the other ends of the two rotating rods are fixedly connected with connecting plates;

[0009] An adjustment component is symmetrically arranged at the bottom of the support platform and is used to adjust the distance between the two movable plates;

[0010] The fixing components are respectively arranged outside the two connecting plates and are used for fixing and clamping the main shaft;

[0011] A top plate, fixedly connected to the upper surface of the support platform through a support frame, and a micrometer is provided below the top plate;

[0012] A moving assembly is arranged at the bottom of the top plate and is used to adjust the horizontal position of the dial gauge;

[0013] The mounting assembly is arranged on the upper surface of the micrometer and is used for disassembling and assembling the micrometer.

[0014] As a further improvement of the present technical solution, the adjustment assembly includes an adjustment plate symmetrically arranged at the bottom of the support platform, the inner side wall of the adjustment plate is rotatably connected to a bidirectional threaded rod, the other end of the bidirectional threaded rod extends to the outside of the adjustment plate and is fixedly connected to a limiting plate, the outside of one of the adjustment plates is fixedly connected to a first motor, the output shaft of the first motor is fixedly connected to one end of one of the bidirectional threaded rods through a coupling, the two bidirectional threaded rods are connected through a synchronous belt and pulley transmission, the outside of the two bidirectional threaded rods are symmetrically provided with thread blocks, the contact surfaces of the two adjustment plates and the support platform are provided with guide grooves for the movement of the thread blocks, and the upper surfaces of each two threaded blocks are respectively fixedly connected to the bottom of the two movable plates.

[0015] As a further improvement of the technical solution, the fixing component includes a plurality of connecting blocks fixedly connected to the outside of the connecting plate. A guide rod is fixedly connected between every two of the connecting blocks. Upper clamping plates and lower clamping plates are respectively arranged on the opposite sides of the two connecting plates. Guide grooves for the movement of the guide rods are formed inside the two upper clamping plates and the lower clamping plates. Return springs are symmetrically sleeved on the outside of the plurality of guide rods. Four of the return springs abut between the upper clamping plate and the connecting block, and the other four return springs abut between the lower clamping plate and the connecting block. Pulling plates are fixedly connected to the outside of the two upper clamping plates and the lower clamping plates.

[0016] As a further improvement of the technical solution, a second motor is fixedly connected to the outside of one of the fixing plates. The output shaft of the second motor is fixedly connected to one end of one of the rotating rods through a coupling.

[0017] As a further improvement of the technical solution, the moving component includes a transmission plate fixedly connected to the bottom of the top plate. A third motor is fixedly connected to one side of the transmission plate. The output shaft of the third motor is fixedly connected to a lead screw through a coupling. The other end of the lead screw is rotatably connected to the inner side wall of the transmission plate. A moving block is threadedly connected to the outside of the lead screw. A guide groove for the movement of the moving block is formed at the bottom of the transmission plate. An electric telescopic rod is fixedly connected to the bottom of the moving block. The telescopic end of the electric telescopic rod is fixedly connected to a mounting plate.

[0018] As a further improvement of the technical solution, the mounting component includes a mounting frame fixedly connected to the upper surface of the dial indicator. A guide groove for the movement of the mounting plate is formed on the upper surface of the mounting frame. An inner plate is fixedly connected to the inside of the mounting plate. Slide rods are symmetrically arranged on both sides of the outer wall of the inner plate. The other ends of the plurality of slide rods are fixedly connected to the inner wall of the mounting plate. Slide plates are symmetrically arranged inside the mounting plate. Guide grooves for the movement of the slide rods are formed inside the two slide plates. Return springs are sleeved on the outside of the plurality of slide rods. The plurality of return springs abut between the slide plate and the inner plate. Plug rods are fixedly connected to the outside of the two slide plates. Guide grooves for the movement of the plug rods are formed on both sides of the outer walls of the mounting plate and the mounting frame.

[0019] Compared with the prior art, the beneficial effects of the present utility model are:

[0020] In this spindle detection device for a numerically controlled machine tool, through the provided adjustment component, fixing component, moving component, and installation component, when it is necessary to detect and process the spindle, only need to first adjust the distance between the two moving plates according to the length of the spindle. At this time, the adjustment component starts to operate, driving the moving plates to move synchronously. At this time, the distance between the two moving plates can be adjusted. The moving plates then drive the fixing plates to move synchronously, and the fixing plates drive the connecting plates and the fixing components to move synchronously. At this time, the spindle is fixed and clamped through the fixing component. After the spindle is fixed, the dial indicator starts to operate. At this time, the spindle can be detected through the dial indicator. During the operation of the dial indicator, the moving component will also start to operate synchronously. At this time, the moving component can effectively adjust the horizontal position of the dial indicator, thereby effectively improving the detection effect of the dial indicator on the spindle and the accuracy of the detection result. When it is necessary to disassemble, replace, and repair the dial indicator, only through the installation component can the dial indicator be conveniently disassembled and assembled, effectively improving the accuracy of the dial indicator during detection, and at the same time improving the overall practicality of the device, saving time and effort. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the overall three-dimensional structure diagram of the present invention;

[0022] Figure 2 is the sectional three-dimensional structure diagram of the adjustment plate in the present invention;

[0023] Figure 3 is the sectional three-dimensional structure diagram of the transmission plate in the present invention;

[0024] Figure 4 is the three-dimensional structure diagram after the dial indicator is disassembled in the present invention;

[0025] Figure 5 is Figure 4 the enlarged structure diagram of area A in

[0026] Figure 6 is Figure 4 the enlarged structure diagram of area B in

[0027] The meanings of each label in the figure are as follows:

[0028] 1. Support platform; 2. Moving plate; 3. Fixed plate; 4. Rotating rod; 5. Connecting plate; 6. Second motor; 7. Top plate; 8. Support frame; 9. Micrometer; 10. Adjusting plate; 11. First motor; 12. Bidirectional threaded rod; 13. Threaded block; 14. Limiting disc; 15. Synchronous belt; 16. Transmission plate; 17. Third motor; 18. Lead screw; 19. Moving block; 20. Electric telescopic rod; 21. Installation frame; 22. Connecting block; 23. Guide rod; 24. Return spring; 25. Upper clamping plate; 26. Lower clamping plate; 27. Installation plate; 28. Inner plate; 29. Slide rod; 30. Slide plate; 31. Contact spring; 32. Insert rod. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figure 1 - Figure 6 as shown, this embodiment provides a spindle detection device for a numerical control machine tool, including a support platform 1, and further including:

[0031] Moving plates 2, symmetrically arranged on the upper surface of the support platform 1, fixed plates 3 are fixedly connected to the upper surfaces of the two moving plates 2, rotating rods 4 are rotatably connected to the opposite sides of the two fixed plates 3, and connecting plates 5 are fixedly connected to the other ends of the two rotating rods 4;

[0032] Adjusting components, symmetrically arranged at the bottom of the support platform 1 and used to adjust the distance between the two moving plates 2;

[0033] Fixing components, respectively arranged outside the two connecting plates 5 and used to fixedly clamp the spindle;

[0034] Top plate 7, fixedly connected to the upper surface of the support platform 1 through a support frame 8, and a micrometer 9 is arranged below the top plate 7;

[0035] Moving components, arranged at the bottom of the top plate 7 and used to adjust the horizontal position of the micrometer 9;

[0036] Installation components, arranged on the upper surface of the micrometer 9 and used to disassemble and assemble the micrometer 9.

[0037] The above working principle: when it is necessary to detect the main shaft, it is only necessary to adjust the distance between the two movable plates 2 according to the length of the main shaft. At this time, the adjusting component starts to run, driving the movable plate 2 to move synchronously. At this time, the distance between the two movable plates 2 can be adjusted, and the movable plate 2 then drives the fixed plate 3 to move synchronously, and the fixed plate 3 then drives the connecting plate 5 and the fixed component to move synchronously. At this time, the main shaft is fixed and clamped by the fixed component. After the main shaft is fixed, the micrometer 9 starts to run. At this time, the main shaft can be detected by the micrometer 9. During the operation of the micrometer 9, the moving component will also start to run synchronously. At this time, the moving component can effectively adjust the horizontal position of the micrometer 9, thereby effectively improving the detection effect of the micrometer 9 on the main shaft and the accuracy of the detection result. When the micrometer 9 needs to be disassembled, replaced and repaired, it is only necessary to install the component to conveniently disassemble and assemble the micrometer 9, which effectively improves the accuracy of the micrometer 9 during detection, and at the same time can improve the overall practicality of the device, saving time and effort.

[0038] In order to effectively adjust the distance between the two movable plates 2, the adjustment component includes an adjustment plate 10 symmetrically arranged at the bottom of the support platform 1, and the inner side wall of the adjustment plate 10 is rotatably connected to a bidirectional threaded rod 12, and the other end of the bidirectional threaded rod 12 extends to the outside of the adjustment plate 10 and is fixedly connected to a limiting disk 14, and the outside of one of the adjustment plates 10 is fixedly connected to a first motor 11, and the output shaft of the first motor 11 is fixedly connected to one end of one of the bidirectional threaded rods 12 through a coupling, and the two bidirectional threaded rods 12 are connected through a synchronous belt 15 and a pulley transmission, and the outsides of the two bidirectional threaded rods 12 are symmetrically provided with thread blocks 13, and the contact surfaces of the two adjustment plates 10 and the support platform 1 are provided with guide grooves for the movement of the thread blocks 13 The upper surfaces of each two threaded blocks 13 are fixedly connected to the bottoms of the two movable plates 2 respectively. When the distance between the two movable plates 2 needs to be adjusted according to actual needs, the first motor 11 starts to run. At this time, the first motor 11 will drive one of the two-way threaded rods 12 to rotate synchronously. Since the two two-way threaded rods 12 are connected by a synchronous belt 15 and a pulley for transmission, the two two-way threaded rods 12 will rotate synchronously at this time, and the threaded blocks 13 will move synchronously outside the two-way threaded rods 12, driving the movable plates 2 to move synchronously. At this time, the distance between the movable plates 2 can be adjusted according to actual needs, so that the fixing assembly can effectively fix and clamp spindles of different specifications.

[0039] Considering that the main shaft needs to be fixed before detection, the fixing component includes a plurality of connecting blocks 22 fixedly connected to the outside of the connecting plate 5. A guide rod 23 is fixedly connected between every two connecting blocks 22. Upper clamping plates 25 and lower clamping plates 26 are respectively arranged on the opposite sides of the two connecting plates 5. Guide grooves for the movement of the guide rod 23 are formed inside the two upper clamping plates 25 and the lower clamping plates 26. Return springs 24 are symmetrically sleeved on the outside of the plurality of guide rods 23. Four of the return springs 24 abut between the upper clamping plate 25 and the connecting block 22, and the other four return springs 24 abut between the lower clamping plate 26 and the connecting block 22. Pulling plates are fixedly connected to the outside of the two upper clamping plates 25 and the lower clamping plates 26. When the main shaft needs to be fixed, only need to pull the pulling plate first. At this time, the pulling plate will drive the upper clamping plate 25 and the lower clamping plate 26 to move synchronously on the outside of the guide rod 23. During the movement of the upper clamping plate 25 and the lower clamping plate 26, the return spring 24 will be compressed. Then place the end of the main shaft between the upper clamping plate 25 and the lower clamping plate 26, and then release the pulling plate. At this time, the return spring 24 resets, driving the upper clamping plate 25 and the lower clamping plate 26 to move synchronously. When the opposite sides of the upper clamping plate 25 and the lower clamping plate 26 abut against the outside of the main shaft, the main shaft can be effectively fixed and clamped through the cooperation between the upper clamping plate 25 and the lower clamping plate 26, so as to facilitate the detection of the main shaft.

[0040] In order to conduct a more comprehensive detection of the main shaft, a second motor 6 is fixedly connected to the outside of one of the fixing plates 3. The output shaft of the second motor 6 is fixedly connected to one end of one of the rotating rods 4 through a coupling. During the detection of the main shaft, the second motor 6 will also start running synchronously. At this time, the second motor 6 will drive one of the rotating rods 4 to rotate synchronously. The rotating rod 4 will then drive the connecting plate 5 to rotate synchronously, and the connecting plate 5 will drive the main shaft to rotate synchronously. At this time, the dial indicator 9 can conduct a more comprehensive detection of the outside of the main shaft, thereby effectively improving the accuracy of the main shaft detection result.

[0041] In order to effectively adjust the horizontal position of the dial indicator 9 so that the dial indicator 9 can perform a more comprehensive detection process on the main shaft, the moving component includes a transmission plate 16 fixedly connected to the bottom of the top plate 7. One side of the transmission plate 16 is fixedly connected with a third motor 17. The output shaft of the third motor 17 is fixedly connected with a lead screw 18 through a coupling. The other end of the lead screw 18 is rotatably connected to the inner side wall of the transmission plate 16. A moving block 19 is threadedly connected to the outside of the lead screw 18. A guiding groove for the movement of the moving block 19 is formed at the bottom of the transmission plate 16. The bottom of the moving block 19 is fixedly connected with an electric telescopic rod 20. The telescopic end of the electric telescopic rod 20 is fixedly connected with a mounting plate 27. When it is necessary to adjust the horizontal position of the dial indicator 9, the third motor 17 starts to operate. At this time, the third motor 17 will drive the lead screw 18 to rotate synchronously. The moving block 19 will move synchronously on the outside of the lead screw 18, driving the electric telescopic rod 20 to move synchronously. The electric telescopic rod 20 then drives the mounting plate 27 and the dial indicator 9 to move synchronously. At this time, the horizontal position of the dial indicator 9 can be adjusted, so that the dial indicator 9 can perform a more comprehensive detection process on the main shaft. When the dial indicator 9 moves to the required position, the electric telescopic rod 20 starts to operate. At this time, the electric telescopic rod 20 will drive the mounting plate 27 to move synchronously. The mounting plate 27 then drives the dial indicator 9 to move synchronously. When the detection end of the dial indicator 9 contacts the outside of the main shaft, the main shaft can be effectively detected through the dial indicator 9.

[0042] In addition, for the convenience of the staff to disassemble and assemble the dial indicator 9, the installation component includes an installation frame 21 fixedly connected to the upper surface of the dial indicator 9. A guiding groove for the movement of the installation plate 27 is provided on the upper surface of the installation frame 21. An inner plate 28 is fixedly connected inside the installation plate 27. Slide rods 29 are symmetrically arranged on both sides of the outer wall of the inner plate 28. The other ends of the multiple slide rods 29 are fixedly connected to the inner wall of the installation plate 27. Slide plates 30 are symmetrically arranged inside the installation plate 27. Guiding grooves for the movement of the slide rods 29 are provided inside the two slide plates 30. Compression springs 31 are sleeved on the outside of the multiple slide rods 29. The multiple compression springs 31 are all abutted between the slide plates 30 and the inner plate 28. Plug rods 32 are fixedly connected to the outside of the two slide plates 30. Guiding grooves for the movement of the plug rods 32 are provided on both sides of the outer walls of the installation plate 27 and the installation frame 21. When it is necessary to disassemble and repair the dial indicator 9, only need to press the plug rods 32 first. At this time, the plug rods 32 will drive the slide plates 30 to move synchronously on the outside of the slide rods 29. During the movement of the slide plates 30, the compression springs 31 will be squeezed synchronously. When the plug rods 32 are disengaged from the guiding grooves on both sides of the outer wall of the installation frame 21, the dial indicator 9 can be disassembled, so as to facilitate the staff to repair and replace the dial indicator 9. When it is necessary to install the dial indicator 9, only need to sleeved the installation frame 21 on the outside of the installation plate 27 first. When the plug rods 32 move to the guiding grooves on both sides of the outer wall of the installation frame 21, the compression springs 31 reset and drive the plug rods 32 to move synchronously. When the plug rods 32 are inserted into the guiding grooves on both sides of the outer wall of the installation frame 21, the installation frame 21 and the installation plate 27 can be fixed, and at this time, the dial indicator 9 can be installed.

[0043] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A spindle detection device for a numerical control machine tool, comprising a support table (1), characterized in that, It further includes: A moving plate (2), symmetrically arranged on the upper surface of the support table (1). Fixed plates (3) are fixedly connected to the upper surfaces of both moving plates (2). Rotating rods (4) are rotatably connected to the opposite sides of both fixed plates (3). Connecting plates (5) are fixedly connected to the other ends of both rotating rods (4). An adjusting assembly, symmetrically arranged at the bottom of the support table (1) and used to adjust the distance between the two moving plates (2). A fixing assembly, respectively arranged outside the two connecting plates (5) and used to fixedly clamp the main shaft. A top plate (7), fixedly connected to the upper surface of the support table (1) through a support frame (8). A dial indicator (9) is arranged below the top plate (7). A moving assembly, arranged at the bottom of the top plate (7) and used to adjust the horizontal position of the dial indicator (9). An installation assembly, arranged on the upper surface of the dial indicator (9) and used to disassemble and assemble the dial indicator (9).

2. The spindle detection device for a numerically controlled machine tool according to claim 1, characterized in that: The adjusting assembly includes adjusting plates (10) symmetrically arranged at the bottom of the support table (1). A bidirectional threaded rod (12) is rotatably connected to the inner side wall of the adjusting plate (10). The other end of the bidirectional threaded rod (12) extends outside the adjusting plate (10) and is fixedly connected to a limit disk (14). A first motor (11) is fixedly connected to the outside of one of the adjusting plates (10). The output shaft of the first motor (11) is fixedly connected to one end of one of the bidirectional threaded rods (12) through a coupling. The two bidirectional threaded rods (12) are connected by a synchronous belt (15) and pulley transmission. Threaded blocks (13) are symmetrically arranged on the outside of both bidirectional threaded rods (12). Guide grooves for the threaded blocks (13) to move are formed on the contact surfaces between the two adjusting plates (10) and the support table (1). The upper surfaces of every two threaded blocks (13) are respectively fixedly connected to the bottoms of the two moving plates (2).

3. The spindle detection device for a numerical control machine tool according to claim 1, wherein: The fixing assembly includes a plurality of connection blocks (22) fixedly connected to the outside of the connecting plate (5). Guide rods (23) are fixedly connected between every two connection blocks (22). An upper clamping plate (25) and a lower clamping plate (26) are respectively arranged on the opposite sides of the two connecting plates (5). Guide grooves for the guide rods (23) to move are formed inside the two upper clamping plates (25) and the lower clamping plate (26). Return springs (24) are symmetrically sleeved on the outside of the plurality of guide rods (23). Four of the return springs (24) are all abutted between the upper clamping plate (25) and the connection block (22), and the other four return springs (24) are all abutted between the lower clamping plate (26) and the connection block (22). Pulling plates are fixedly connected to the outsides of the two upper clamping plates (25) and the lower clamping plate (26).

4. A spindle detection device for a numerical control machine tool according to claim 1, characterized in that: A second motor (6) is fixedly connected to the outside of one of the fixed plates (3). The output shaft of the second motor (6) is fixedly connected to one end of one of the rotating rods (4) through a coupling.

5. A spindle detection device for a numerical control machine tool according to claim 1, characterized in that: The moving component includes a transmission plate (16) fixedly connected to the bottom of the top plate (7). One side of the transmission plate (16) is fixedly connected with a third motor (17). The output shaft of the third motor (17) is fixedly connected with a lead screw (18) through a coupling. The other end of the lead screw (18) is rotatably connected to the inner side wall of the transmission plate (16). A moving block (19) is threadedly connected to the outside of the lead screw (18). A guiding groove for the movement of the moving block (19) is formed at the bottom of the transmission plate (16). The bottom of the moving block (19) is fixedly connected with an electric telescopic rod (20). The telescopic end of the electric telescopic rod (20) is fixedly connected with a mounting plate (27).

6. The spindle detection device for a numerically controlled machine tool according to claim 5, characterized in that: The mounting component includes a mounting frame (21) fixedly connected to the upper surface of the dial indicator (9). A guiding groove for the movement of the mounting plate (27) is formed on the upper surface of the mounting frame (21). An inner plate (28) is fixedly connected to the inside of the mounting plate (27). Slide bars (29) are symmetrically arranged on both sides of the outer wall of the inner plate (28). The other ends of the plurality of slide bars (29) are fixedly connected to the inner wall of the mounting plate (27). Slide plates (30) are symmetrically arranged inside the mounting plate (27). Guiding grooves for the movement of the slide bars (29) are formed inside the two slide plates (30). A plurality of compression springs (31) are sleeved on the outside of the plurality of slide bars (29). The plurality of compression springs (31) are all abutted between the slide plates (30) and the inner plate (28). Plug rods (32) are fixedly connected to the outside of the two slide plates (30). Guiding grooves for the movement of the plug rods (32) are formed on both sides of the outer walls of the mounting plate (27) and the mounting frame (21).

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