Die cutting device for carton production

Abstract

The invention relates to the technical field of carton production equipment, in particular to a die cutting device for carton production. The conveying mechanism is used for conveying the raw material paperboard; the die cutting mechanism is used for carrying out die cutting on the paperboards; the deburring mechanism is used for polishing the die cutting position; the driving mechanism is used for driving the die cutting mechanism and the deburring mechanism; the conveying mechanism is connected to the middle of the interior of the rack, the die cutting mechanism is slidably connected to the top end of the inner side of the rack, the deburring mechanism is slidably connected to the bottom end of the inner side of the rack, and the driving mechanism is connected to the rack. The arranged die cutting mechanism can conduct die cutting operation on paperboards, a sliding type limiting structure can conveniently conduct moving adjustment on the die cutting position, a swinging die cutter can move and swing along with a moving base, the moving track of the die cutter is of a strip-shaped structure, and the die cutting device is convenient to use. And a paperboard can be subjected to die cutting forming, and the joint of waste and the paperboard is directly cut, so that the requirements of different die cutting positions are met, and the application range of the device is widened.

Description

Technical Field

[0001] The invention relates to the technical field of carton production equipment, and in particular to a die-cutting device for carton production. Background Art

[0002] Carton is a kind of packaging product that is most widely used in modern society. When people produce cartons, they need to use a die-cutting machine to die-cut the cardboard. In order to produce a set box, the die-cutting machine cuts a long rectangular waste material from the front and rear of the cardboard symmetrically in the middle position, and the cardboard after die-cutting is conveniently folded into a set box. Most of the die-cutting structures in the prior art use parallel knives to cut the cardboard to form a long strip of die-cut grooves, such as the adjustment device of the slotting knife of the carton forming machine disclosed in the publication number CN104325695B, which cuts the cardboard into strip grooves through parallel knives. However, the knives of the above-mentioned device need to adjust four groups of knives one by one when adjusting, and cannot conveniently adapt to the die-cutting processing requirements of different spacings. At the same time, if the knife does not cut the connection between the waste material and the cardboard, the waste material will have pulling defects when it is removed. If the knife cuts the connection between the waste material and the cardboard, the die-cutting depth cannot be adjusted.

[0003] At the same time, because the cardboard is a composite paper material, when the cardboard is subjected to the die-cutting operation of the die-cutting tool or the extrusion of the side of the die-cutting tool during the die-cutting process, the die-cutting part of the cardboard will be uneven, such as being concave inward or convex outward, which will affect the quality of the subsequent die-cutting cardboard. In view of this, we propose a die-cutting device for carton production. Summary of the invention

[0004] The object of the present invention is to provide a die-cutting device for carton production, which solves the problems in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A die-cutting device for carton production, comprising a frame;

[0007] Conveying mechanism, used for conveying raw paperboard;

[0008] A die-cutting mechanism, used for die-cutting cardboard;

[0009] Deburring mechanism, used for grinding the die-cutting area;

[0010] A driving mechanism, used for driving a die-cutting mechanism and a deburring mechanism;

[0011] The conveying mechanism is connected to the middle of the frame, the die-cutting mechanism is slidably connected to the top inner side of the frame, the deburring mechanism is slidably connected to the bottom inner side of the frame, and the driving mechanism is connected to the frame.

[0012] Preferably, the deburring mechanism includes a support base slidably connected to the inner bottom end of the frame. Two adjusting frames are slidably connected to the support base. A moving frame is slidably connected to the adjusting frames. The moving frame has a "C" - shaped structure. A polishing rod is rotatably connected to the inner side of the moving frame. A connecting rod is slidably connected to the moving frame and penetrates through the moving frame.

[0013] Preferably, a positioning block is fixedly connected to the polishing rod. A buffer spring is fixedly connected to the inner side of the positioning block. The end of the buffer spring is fixedly connected to a polishing block. The end of the polishing rod is connected to a motor.

[0014] Preferably, the die - cutting mechanism includes a support frame slidably connected to the inner top end of the frame. A positioning frame is slidably connected to the inner side of the support frame. A moving groove is formed in the middle of the positioning frame. A die - cutting knife is slidably connected to the inner side of the positioning frame. A moving component is provided on the support frame.

[0015] Preferably, the moving component includes two moving seats slidably connected to both sides of the top end of the support frame. A driving rod is rotatably connected to the inner side of each moving seat, and the end of the driving rod is rotatably connected to the outer top end of the cutting knife.

[0016] Preferably, a connecting rod is rotatably connected to the middle of the moving seat. The end of the connecting rod away from the moving seat is rotatably connected to a linkage rod, and the linkage rod is slidably connected inside the frame.

[0017] Preferably, the moving groove has a trapezoidal structure with a wider top and a narrower bottom. A support block is slidably connected to the inner bottom end of the moving groove, and the die - cutting knife is rotatably connected inside the support block.

[0018] Preferably, the driving mechanism includes an electric push rod fixedly connected to the top end of the frame. The output end of the electric push rod is fixedly connected to the top end of the support frame. A linkage frame is fixedly connected between the support frame and the support base.

[0019] Preferably, piston cylinders are fixedly connected to both the support frame and the support base. A piston rod is slidably connected inside each piston cylinder. The ends of the piston rods are respectively fixedly connected to the outer sides of the moving seats and the moving frames. The end of each piston cylinder is fixedly connected to an intake pipe. The ends of the intake pipes are respectively fixedly connected to the inner side of the linkage frame. A sealing cylinder is slidably connected to the outer side of the intake pipe, and the sealing cylinder is connected to a cylinder through a pipeline.

[0020] Preferably, the conveying mechanism includes a conveyor belt device symmetrically connected to both sides of the middle of the frame. Fixing blocks are fixedly connected to the conveyor belt device. A return spring is fixedly connected to the top of the fixing block. The end of the return spring is fixedly connected to a clamping block, and clamping grooves are formed on both sides of the clamping block.

[0021] By means of the above technical solution, the present invention provides a die-cutting device for carton production, which has at least the following beneficial effects:

[0022] (1) The present invention can perform die-cutting operations on cardboard through the die-cutting mechanism, and the sliding limit structure can conveniently move and adjust the die-cutting position. The swinging die-cutting knife can move and swing with the moving seat, so that the moving track of the die-cutting knife presents a strip structure, and the cardboard can be die-cut into shape and the connection between the waste material and the cardboard can be directly cut, thereby adapting to the needs of different die-cutting positions and improving the application range of the device.

[0023] (2) The deburring mechanism of the present invention can continuously polish the die-cut portion of the cardboard by using a polishing structure with a width close to that of the die-cut portion after the die-cutting operation on the cardboard is completed. At the same time, the polishing block sliding on the polishing rod can use the elasticity of the buffer spring to press the polishing block against both sides of the cardboard, thereby continuously polishing the cardboard and improving the flatness of the die-cut edge of the cardboard.

[0024] (3) The clamping conveying structure provided in the present invention can clamp the cardboard during the conveying process, and use the elasticity of the return spring to pull the clamping block inward, so that the cardboard is clamped and fixed on the surface of the conveyor belt, thereby improving the stability of the cardboard during the die-cutting and polishing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application:

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 It is a schematic diagram of the internal structure of the present invention;

[0028] Figure 3 It is a schematic diagram of the structure of the conveying mechanism of the present invention;

[0029] Figure 4 It is a schematic diagram of the die-cutting mechanism structure of the present invention;

[0030] Figure 5 The deburring mechanism structure of the present invention is shown in FIG. Figure 1 ;

[0031] Figure 6 The deburring mechanism structure of the present invention is shown in FIG. Figure 2 ;

[0032] Figure 7 It is a schematic diagram of the driving mechanism structure of the present invention.

[0033] In the figure: 1. frame; 2. conveying mechanism; 21. conveyor belt device; 22. fixed block; 23. return spring; 24. clamping block; 3. die-cutting mechanism; 31. support frame; 32. positioning frame; 33. moving groove; 34. die-cutting knife; 35. moving assembly; 351. moving seat; 352. driving rod; 353. connecting rod; 354. linkage rod; 36. support block; 4. deburring mechanism; 41. support seat; 42. adjusting frame; 43. moving frame; 44. grinding rod; 45. connecting rod; 46. positioning block; 47. buffer spring; 48. grinding block; 5. driving mechanism; 51. electric push rod; 52. linkage frame; 53. piston cylinder; 54. piston rod; 55. air inlet pipe; 56. sealing cylinder; 57. cylinder. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] A die-cutting device for carton production, such as Figure 1 , Figure 5 , Figure 6 As shown, it includes a frame 1; a deburring mechanism 4 is slidably connected to the inner bottom end of the frame 1 for grinding the die-cutting part; the deburring mechanism 4 can remove the burrs generated after the raw material cardboard is cut, so that the edge of the cut part is smoother and flatter.

[0037] Specifically, the deburring mechanism 4 includes a support base 41 which is slidably connected to the inner bottom end of the frame 1. The structure of the support base 41 can adjust the height of the entire deburring mechanism 4, thereby realizing the switching between the deburring of the cardboard grinding groove by the deburring mechanism 4 and the separation operation of the deburring mechanism 4 from the cardboard. Two adjusting frames 42 are slidably connected to the support base 41, and a moving frame 43 is slidably connected to the adjusting frames 42. The structure of the adjusting frames 42 can adjust the position of the grinding structure, so that the grinding structure can adapt to different cutting spacings. The moving frame 43 is in a "C" - shaped structure. A grinding rod 44 is rotatably connected to the inner side of the moving frame 43. The width of the moving frame 43 is smaller than the diameter of the grinding rod 44. The grinding rod 44 and the moving frame 43 can move to the cutting position, so as to perform synchronous grinding operations on both sides of the cutting position. The "C" - shaped moving frame 43 can improve the stability of the grinding rod 44 during rotation. A connecting rod 45 is slidably connected to the moving frame 43. The connecting rod 45 penetrates through the moving frame 43. The structure of the connecting rod 45 can make the two moving frames 43 on one side move synchronously, so as to perform synchronous deburring operations on the two cutting grooves on one side at the same time.

[0038] In addition, a positioning block 46 is fixedly connected to the grinding rod 44. A buffer spring 47 is fixedly connected to the inner side of the positioning block 46. The end of the buffer spring 47 is fixedly connected to a grinding block 48. The structure of the positioning block 46 can limit the grinding block 48, so that the grinding blocks 48 approach each other and perform grinding operations on the edges of both sides of the cardboard. The grinding block 48 is in a frustum - shaped structure. The end of the grinding rod 44 is connected to a motor. The frustum - shaped structure can facilitate the insertion of the cardboard into the gap between the grinding blocks 48. At the same time, the motor can drive the grinding rod 44 and the grinding blocks 48.

[0039] Embodiment 2

[0040] As Figure 1 、 Figure 2 、 Figure 4 shown, on the basis of Embodiment 1, a die - cutting mechanism 3 is slidably connected to the inner top end of the frame 1 for die - cutting the cardboard.

[0041] In this embodiment, the die - cutting mechanism 3 includes a support frame 31 which is slidably connected to the inner top end of the frame 1. The structure of the support frame 31 can support the entire die - cutting mechanism 3. At the same time, the slidable support frame 31 can cooperate with the deburring mechanism 4 to realize the switching between die - cutting and deburring of the cardboard. A positioning frame 32 is slidably connected to the inner side of the support frame 31. The structure of the positioning frame 32 can position the die - cutting tool 34 to adapt to die - cutting requirements with different spacings. A moving groove 33 is formed in the middle of the positioning frame 32. A die - cutting knife 34 is slidably connected to the inner side of the positioning frame 32. The slidable die - cutting knife 34 can perform die - cutting operations on the raw cardboard. A moving component 35 is arranged on the support frame 31. The moving component 35 can move the die - cutting knife 34 so that the die - cutting knife 34 can move along the moving groove 33.

[0042] Furthermore, the moving assembly 35 includes a moving seat 351, and two moving seats 351 are provided. The two moving seats 351 are slidably connected to the two sides of the top of the support frame 31. The inner side of the moving seat 351 is rotatably connected to a driving rod 352, and the end of the driving rod 352 is rotated at the top of the outer side of the cutting knife. The driving rod 352 structure can control the position of the cutting knife. At the same time, the end of the driving rod 352 is a universal joint structure, which can rotate in multiple directions.

[0043] It is worth noting that a connecting rod 353 is rotatably connected in the middle of the movable seat 351, and one end of the connecting rod 353 away from the movable seat 351 is rotatably connected to a linkage rod 354, and the linkage rod 354 is slidably connected inside the frame 1. The connecting rod 353 structure can cooperate with the linkage rod 354 to make the two connecting rods 353 rotate synchronously, thereby realizing the toward or reverse movement of the two movable seats 351, and then the die-cutting knife 34 can move synchronously to perform cutting operations.

[0044] On this basis, the movable groove 33 is a trapezoidal structure that is wide at the top and narrow at the bottom. The movable groove 33 of the trapezoidal structure can make the die cutter 34 slide close to the groove wall of the movable groove 33 when driven by the driving rod 352, so that the end track of the die cutter 34 is strip-shaped. The bottom end of the movable groove 33 is slidably connected with a support block 36, and the die cutter 34 is rotatably connected inside the support block 36. The rotation direction of the die cutter 34 is perpendicular to the direction of the movable groove 33. The support block 36 structure can position the die cutter 34 so that the die cutter 34 can only swing left and right during the sliding process.

[0045] Example 3

[0046] like Figure 1 , Figure 2 , Figure 3 , Figure 7 As shown, on the basis of embodiment 2, a driving mechanism 5 is connected to the frame 1 for driving the die-cutting mechanism 3 and the deburring mechanism 4. A conveying mechanism 2 is connected in the middle of the frame 1 for conveying the raw paperboard.

[0047] In this embodiment, the driving mechanism 5 includes an electric push rod 51, which is fixedly connected to the top of the frame 1, and the output end of the electric push rod 51 is fixedly connected to the top of the support frame 31. The electric push rod 51 can drive the support frame 31 to move and adjust the support frame 31. A linkage frame 52 is fixedly connected between the support frame 31 and the support seat 41, and the linkage frame 52 can connect the support frame 31 with the support seat 41, so as to drive the support frame 31 to move and drive the support seat 41 to move synchronously.

[0048] It is worth noting that the support frame 31 and the support seat 41 are both fixedly connected with a piston cylinder 53, and a piston rod 54 is slidably connected inside the piston cylinder 53. The ends of the piston rod 54 are respectively fixedly connected to the outside of the moving seat 351 and the moving frame 43. The piston cylinder 53 structure can cooperate with the piston rod 54, so that the piston rod 54 can drive the moving seat 351 and the moving frame 43 respectively, so as to realize the movement of the moving seat 351 and the moving frame 43. The end of the piston cylinder 53 is fixedly connected with an air intake pipe 55, and the air intake pipe 55 structure is interconnected with the inside of the piston cylinder 53. The forward or reverse movement of the moving frame 43 and the moving seat 351 can be realized by pumping or exhausting air into the piston cylinder 53 through the air intake pipe 55. The ends of the air intake pipe 55 are respectively fixedly connected to the inner side of the linkage frame 52, and a sealing cylinder 56 is slidably connected to the outer side of the air intake pipe 55. The sealing cylinder 56 is connected to the cylinder 57 through a pipeline. The sealing cylinder 56 structure can slide on the outer side of the air intake pipe 55 when the linkage frame 52 moves up and down, so as to switch between the two air intake pipes 55. At the same time, the pipe mouth of the air intake pipe 55 is on the side. After the sealing cylinder 56 is switched, different piston cylinders 53 can be driven. At the same time, the cylinder 57 can pump or exhaust air into the sealing cylinder 56 through the pipeline.

[0049] In addition, the conveying mechanism 2 includes a conveyor belt device 21, which is symmetrically connected to both sides of the middle of the frame 1. The conveyor belt device 21 can convey the cardboard so that the cardboard moves from the edge of the frame 1 to the middle of the frame 1. A fixed block 22 is fixedly connected to the conveyor belt device 21, a return spring 23 is fixedly connected to the top of the fixed block 22, and a clamping block 24 is fixedly connected to the end of the return spring 23. Clamping grooves are provided on both sides of the clamping block 24. The clamping block 24 and the return spring 23 can cooperate with each other to clamp and fix the raw cardboard, thereby maintaining the stability of the cardboard during the die-cutting process. At the same time, the clamping groove structure on the side of the clamping block 24 can cooperate with the edges at both ends of the cardboard to further improve the stability of the cardboard and prevent the cardboard from shaking along the conveying direction of the conveyor belt.

[0050] When the die-cutting device for carton production of the present invention is used, the raw paperboard is first placed on the conveyor belt device 21, and the raw paperboard is clamped and fixed by the clamping block 24. The conveyor belt device 21 is then started to move the raw paperboard to the middle of the frame 1, and then the push rod motor is started to move the support frame 31 downward, and the die-cutting knife 34 is moved to both sides of the raw paperboard. While the support frame 31 moves, the linkage frame 52 and the air inlet pipe 55 inside the linkage frame 52 move downward, and the sealing cylinder 56 outside the air inlet pipe 55 moves upward along the air inlet pipe 55. Then the die-cutting knife 34 and the cylinder 57 are started, and the cylinder 57 extracts the air inside the sealing cylinder 56 through the pipeline, and the air inside the piston cylinder 53 flows through the air inlet pipe 55 to the inside of the cylinder 57, and the piston rod 54 moves outward and drives the moving seat 351 to move. When the movable seat 351 moves, one end of the connecting rod 353 moves synchronously, and the other end of the connecting rod 353 drives the linkage rod 354 to move downward. When the linkage rod 354 moves downward, it drives one end of the other connecting rod 353 to move downward, and the other movable seat 351 moves outward accordingly, thereby realizing the reverse movement of the two movable seats 351. When the movable seat 351 moves outward, the die-cutting knife 34 is pulled outward by the inner driving rod 352, and the die-cutting knife 34 tilts outward accordingly. The driving rod 352 and the movable groove 33 are inclined, so when the movable seat 351 moves outward, the force of the driving rod 352 drives the die-cutting knife 34 to move inward along the movable groove 33, and the cardboard is die-cut. When the movable seat 351 moves to the outermost side, the cylinder 57 pumps air into the sealing tube 56 through the pipeline, and the two movable seats 351 move toward each other accordingly. The inward moving seat 351 pushes the die cutter 34 to tilt inward and pushes the die cutter 34 outward, and the die cutter 34 cuts a long strip of grooves on the cardboard. After the die cutting operation is completed, the electric push rod 51 pushes the support seat 41 and the support frame 31 to move upward, and the sealing cylinder 56 switches to another air inlet pipe 55. At the same time, the cylinder 57 starts to pump air again to move the moving frame 43 to the outside of the cardboard. When the grinding block 48 moves to the position corresponding to the cardboard, the electric push rod 51 stops running. Then the cylinder 57 starts and pushes the moving frame 43 inward and outward through the piston rod 54. When the grinding block 48 moves back and forth once, the cardboard moves between the grinding blocks 48. Under the elastic action of the buffer spring 47, the grinding block 48 is close to the cardboard and grinds the edge of the cardboard. At the same time, the grinding rod 44 deburrs the side of the cardboard die-cutting area. After the deburring operation is completed, the electric push rod 51 drives the support seat 41 and the support frame 31 to move again, so that the cardboard is located between the die cutter 34 and the polishing rod 44, and then the cardboard moves toward the downward direction under the conveyor belt device 21.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A die-cutting device for carton production, characterized in that: It includes a frame (1); A conveying mechanism (2) for conveying raw cardboard; A die-cutting mechanism (3) for die-cutting the cardboard; A deburring mechanism (4) for polishing the die-cutting area; A driving mechanism (5) for driving the die-cutting mechanism (3) and the deburring mechanism (4); The conveying mechanism (2) is connected to the middle inside the frame (1), the die-cutting mechanism (3) is slidably connected to the top end inside the frame (1), the deburring mechanism (4) is slidably connected to the bottom end inside the frame (1), and the driving mechanism (5) is connected to the frame (1).

2. A die-cutting device for carton production according to claim 1, characterized in that: The deburring mechanism (4) includes a support base (41), the support base (41) is slidably connected to the bottom end inside the frame (1), two adjusting frames (42) are slidably connected to the support base (41), a moving frame (43) is slidably connected to the adjusting frame (42), the moving frame (43) has a "C" - shaped structure, a polishing rod (44) is rotatably connected to the inside of the moving frame (43), a connecting rod (45) is slidably connected to the moving frame (43), and the connecting rod (45) penetrates through the moving frame (43).

3. A die-cutting device for carton production according to claim 2, characterized in that: A positioning block (46) is fixedly connected to the polishing rod (44), a buffer spring (47) is fixedly connected to the inside of the positioning block (46), a polishing block (48) is fixedly connected to the end of the buffer spring (47), and a motor is connected to the end of the polishing rod (44).

4. A die-cutting device for carton production according to claim 1, characterized in that: The die-cutting mechanism (3) includes a support frame (31), the support frame (31) is slidably connected to the top end inside the frame (1), a positioning frame (32) is slidably connected to the inside of the support frame (31), a moving groove (33) is formed in the middle of the positioning frame (32), a die-cutting knife (34) is slidably connected to the inside of the positioning frame (32), and a moving component (35) is provided on the support frame (31).

5. A die-cutting device for carton production according to claim 4, characterized in that: The moving component (35) includes moving seats (351), there are two moving seats (351), the two moving seats (351) are slidably connected to both sides of the top end of the support frame (31), a driving rod (352) is rotatably connected to the inside of the moving seat (351), and the end of the driving rod (352) rotates at the top end outside the cutting knife.

6. A die-cutting device for carton production according to claim 5, characterized in that: A connecting rod (353) is rotatably connected to the middle of the moving seat (351), one end of the connecting rod (353) away from the moving seat (351) is rotatably connected to a linkage rod (354), and the linkage rod (354) is slidably connected to the inside of the frame (1).

7. A die-cutting device for carton production according to claim 4, characterized in that: The moving groove (33) has a trapezoidal structure with a wider top and a narrower bottom, a support block (36) is slidably connected to the bottom end inside the moving groove (33), and the die-cutting knife (34) is rotatably connected to the inside of the support block (36).

8. A die-cutting device for carton production according to claim 4, characterized in that: The driving mechanism (5) includes an electric push rod (51), the electric push rod (51) is fixedly connected to the top end of the frame (1), the output end of the electric push rod (51) is fixedly connected to the top end of the support frame (31), and a linkage frame (52) is fixedly connected between the support frame (31) and the support base (41).

9. A die-cutting device for carton production according to claim 4, characterized in that: The support frame (31) and the support seat (41) are both fixedly connected with a piston cylinder (53), the piston cylinder (53) is slidably connected with a piston rod (54), the ends of the piston rod (54) are respectively fixedly connected to the outer sides of the movable seat (351) and the movable frame (43), the ends of the piston cylinder (53) are fixedly connected with an air intake pipe (55), the ends of the air intake pipe (55) are respectively fixedly connected to the inner side of the linkage frame (52), the outer side of the air intake pipe (55) is slidably connected with a sealing cylinder (56), and the sealing cylinder (56) is connected to a cylinder (57) via a pipeline.

10. A die-cutting device for carton production according to claim 1, characterized in that: The conveying mechanism (2) comprises a conveyor belt device (21), the conveyor belt device (21) is symmetrically connected to the middle two sides of the frame (1), a fixed block (22) is fixedly connected to the conveyor belt device (21), a return spring (23) is fixedly connected to the top of the fixed block (22), a clamping block (24) is fixedly connected to the end of the return spring (23), and clamping grooves are provided on both sides of the clamping block (24).

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