Positioning tool for CCD (Charge Coupled Device) detection and deviation rectification of pole piece

Abstract

The utility model relates to the technical field of pole piece CCD detection, in particular to a positioning tool for pole piece CCD detection deviation rectification, which comprises a machine base, a machine frame is fixedly arranged on the machine base, a set of cameras are arranged on the machine base in a sliding mode, a transparent bottom plate is arranged above the cameras jointly, an installation frame is sleeved on the transparent bottom plate, the transparent bottom plate is fixedly connected with the installation frame, and the installation frame is fixedly connected with the machine frame. A deviation rectifying assembly is arranged between the mounting frame and the rack and used for driving the mounting frame to move, a set of transparent pressing plates are movably arranged above the transparent bottom plate, and the transparent pressing plates are symmetrically arranged. The device has the effect of facilitating CCD detection and deviation correction of the pole pieces of different specifications.

Description

Technical Field

[0001] The utility model relates to the technical field of pole piece CCD detection, in particular to a positioning tool for pole piece CCD detection and deviation correction. Background Art

[0002] At present, the pole piece adopts the method of CCD photography and standard positioning comparison to correct positioning, but the pole piece will warp under the action of internal stress, resulting in inaccurate CCD edge grasping and point picking. Therefore, before CCD photography, a transparent plate is used to press the edge of the pole piece to improve the accuracy of CCD edge grasping and point picking.

[0003] In the related art, a Chinese patent with authorization announcement number CN217900751U is designed to provide a pole piece CCD detection and correction positioning mechanism, which includes a bottom plate, a correction driving mechanism is arranged on the bottom plate, a suction plate is arranged on the correction driving mechanism, the correction driving mechanism is used to drive the suction plate to move in the horizontal plane, the suction plate is used to adsorb the pole piece, a camera is arranged on the bottom plate, a notch for camera shooting is opened on the suction plate, a support frame is arranged on the bottom plate, a lifting device is arranged on the support frame, a transparent pressing plate is arranged on the lifting device, the transparent pressing plate is arranged at the notch of the suction plate, and the lifting device is used to drive the transparent pressing plate to move up and down. After the pole piece is adsorbed on the suction plate by vacuum, the lifting mechanism drives the transparent pressing plate to press the pole piece to make the edge and corner of the pole piece flat, and then the camera takes a picture of the diagonal of the pole piece, calculates the deviation value between the pole piece and the standard position, and finally adjusts the position of the pole piece by the correction driving mechanism.

[0004] In the process of implementing the present application, the inventors discovered that there are at least the following problems in the technology: since the pole piece is located diagonally between the transparent pressure plate and the camera for detection, and the transparent pressure plate and the camera will not move relative to the base in the horizontal direction, when the pole piece size is larger or smaller, one corner of the pole piece will not be located between the transparent pressure plate and the camera, resulting in a small application range of the pole piece CCD detection correction positioning mechanism. Utility Model Content

[0005] In order to facilitate CCD detection and correction of pole pieces of different specifications, the present application provides a positioning tool for CCD detection and correction of pole pieces.

[0006] The present application provides a positioning tool for pole piece CCD detection and correction, which adopts the following technical solution:

[0007] A positioning tool for pole piece CCD detection and correction comprises a machine base, a frame is fixedly arranged on the machine base, a group of cameras are slidably arranged on the machine base, a transparent bottom plate is commonly arranged above the cameras, a mounting frame is sleeved on the transparent bottom plate, the transparent bottom plate is fixedly connected to the mounting frame, a correction component is arranged between the mounting frame and the frame, the correction component is used to drive the mounting frame to move, a group of transparent pressure plates are movably arranged above the transparent bottom plate, and the transparent pressure plates are symmetrically arranged.

[0008] By adopting the above technical scheme, when the transparent pressing plate presses the pole piece onto the transparent bottom plate, the edge corners of the pole piece are flattened, and then the camera takes a picture of the diagonal corners of the pole piece, the deviation value between the pole piece and the marked position is calculated, and finally the position of the pole piece is adjusted by the correction drive mechanism. According to the size specifications of the pole piece, the camera position is moved so that the diagonal corners of the pole piece are located between the transparent pressing plate and the camera, so as to facilitate CCD detection and correction of pole pieces of different specifications, thereby improving the application scope of the pole piece CCD detection and correction positioning mechanism.

[0009] Preferably, a group of transverse shift grooves are provided on the machine base, a transverse shift seat is slidably arranged in the transverse shift grooves, the top of the transverse shift seat is connected to the bottom of the camera, a transverse shift screw is rotatably arranged in the transverse shift grooves, and the transverse shift screw is threadedly connected to the transverse shift seat.

[0010] By adopting the above technical solution, the rotation of the transverse moving screw drives the transverse moving seat to move along the transverse groove, thereby achieving the effect of moving the camera along the length direction of the seat.

[0011] Preferably, a longitudinal shift groove is provided on the top of the transverse shift seat, a longitudinal shift block is slidably arranged in the longitudinal shift groove, the top of the longitudinal shift block is fixedly connected to the bottom of the camera, a longitudinal shift screw is rotatably arranged in the longitudinal shift groove, and the longitudinal shift screw is threadedly connected to the longitudinal shift block.

[0012] By adopting the above technical solution, the rotation of the longitudinal moving screw drives the longitudinal moving block to move along the longitudinal moving groove, thereby achieving the effect of moving the camera along the width direction of the base.

[0013] Preferably, the correction assembly includes a group of transverse cylinders and a group of longitudinal cylinders, the transverse cylinders are fixedly connected to the frame, the output shafts of the transverse cylinders are relatively arranged, and the output shafts of the transverse cylinders are slidably connected to the side walls of the mounting frame, and the longitudinal cylinders are fixedly connected to the frame, the output shafts of the longitudinal cylinders are relatively arranged, and the output shafts of the longitudinal cylinders are slidably connected to the end walls of the mounting frame.

[0014] By adopting the above technical scheme, when the output shaft of one transverse moving cylinder is lengthened, the output shaft of the other transverse moving cylinder is shortened, so that the installation frame drives the transparent bottom plate to move along the length direction of the machine base, and at the same time, the output shaft of the longitudinal moving cylinder and the installation frame move relative to each other along the length direction of the machine base. When the output shaft of one longitudinal moving cylinder is lengthened, the output shaft of the other longitudinal moving cylinder is shortened, so that the installation frame drives the transparent bottom plate to move along the width direction of the machine base, and at the same time, the output shaft of the transverse moving cylinder and the installation frame move relative to each other along the width direction of the machine base, and then through the cooperation of the transverse moving cylinder and the longitudinal moving cylinder, the transparent bottom plate drives the pole piece to move, thereby achieving the effect of pole piece correction.

[0015] Preferably, a correction motor is fixedly arranged at the bottom of the installation frame, a transparent base is fixedly arranged at the bottom of the correction motor, a transverse sliding groove is provided on the side wall of the transparent base, a transverse slider is slidably arranged in the transverse sliding groove, the back surface of the transverse slider is fixedly connected to the opposite surface of the transverse cylinder, and a longitudinal sliding groove is provided on the end wall of the transparent base, a longitudinal slider is slidably arranged in the longitudinal sliding groove, and the back surface of the longitudinal slider is fixedly connected to the opposite surface of the longitudinal cylinder.

[0016] By adopting the above technical scheme, when the output shaft of the transverse movement cylinder moves, the transparent base drives the installation frame to move along the length direction of the machine base, and the longitudinal slider moves along the longitudinal slide groove, so that the output shaft of the longitudinal movement cylinder and the transparent base move relative to each other along the length direction of the machine base; when the output shaft of the longitudinal movement cylinder moves, the transparent base drives the installation frame to move along the width direction of the machine base, and the transverse slider moves along the transverse slide groove, so that the output shaft of the transverse movement cylinder and the transparent base move relative to each other along the width direction of the machine base; when the deviation correction motor is started, the deviation correction motor drives the installation frame to rotate, so that the transparent bottom plate drives the pole piece to move, thereby achieving the effect of pole piece correction.

[0017] Preferably, a group of driving grooves are opened on the top of the installation frame, a group of driving racks are slidably arranged in the driving grooves, a plurality of driving gears are meshed on the driving racks, a driving arm is fixedly arranged on the driving gears, and the driving arm is rotatably connected to the side wall of the transparent pressure plate.

[0018] By adopting the above technical solution, when the driving racks approach each other, the driving rack drives the driving gear to rotate, the rotation of the driving gear drives the driving arm to rotate, the rotation of the driving arm drives the transparent pressure plate to approach each other, and the transparent pressure plate moves toward the transparent bottom plate, thereby achieving the effect of the transparent pressure plate pressing the electrode onto the transparent bottom plate.

[0019] Preferably, a forward screw and a reverse screw are rotatably arranged in the driving groove, the forward screw is threadedly connected to a forward slider, the forward slider is fixedly connected to one of the driving racks, the reverse screw is threadedly connected to a reverse slider, and the reverse slider is fixedly connected to the other driving rack.

[0020] By adopting the above technical solution, when the forward screw rotates, the forward screw drives the forward slider to move along the drive groove, and the forward slider drives one of the drive racks to move; when the reverse screw rotates, the reverse screw drives the reverse slider to move along the drive groove, and the reverse slider drives the other drive rack to move, thereby achieving the effect of relative movement of the drive racks in the same drive groove.

[0021] Preferably, a drive motor is fixedly arranged in the drive slot, the output shaft of the drive motor is fixedly connected to one end of the forward screw rod, the other end of the forward screw rod is fixedly connected to one end of the reverse screw rod, and the other end of the reverse screw rod is rotatably connected to the inner wall of the drive slot.

[0022] By adopting the above technical solution, the rotation of the driving motor drives the forward screw to rotate, and the rotation of the forward screw drives the reverse screw to rotate, thereby achieving the effect of synchronous rotation of the forward screw and the reverse screw.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. By setting up the machine base, frame, camera, transparent bottom plate, mounting frame, correction component and transparent pressure plate, it is convenient for pole pieces of different specifications to perform CCD detection and correction, and improve the application scope of the pole piece CCD detection and correction positioning mechanism;

[0025] 2. By setting the transverse shift groove, transverse shift seat and transverse shift screw rod, the camera can be moved along the length direction of the base;

[0026] 3. By setting the longitudinal movement groove, longitudinal movement block and longitudinal movement screw rod, the effect of moving the camera along the width direction of the base is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view of a positioning tooling structure for pole piece CCD detection and correction in an embodiment of the present application.

[0028] Figure 2 It is a schematic diagram showing the connection relationship between the camera and the base in the embodiment of the present application.

[0029] Figure 3 It is a cross-sectional view showing the connection relationship between the frame and the transparent base in the embodiment of the present application.

[0030] Figure 4 It is a cross-sectional view of the mounting frame and the transparent pressing plate in the embodiment of the present application.

[0031] Figure 5 yes Figure 4 Enlarged view of part A.

[0032] Explanation of the reference numerals in the accompanying drawings: 1. base; 11. frame; 2. camera; 3. transparent bottom plate; 31. transparent pressure plate; 4. mounting frame; 5. deviation correction assembly; 51. transverse cylinder; 511. transverse slider; 512. transverse slide groove; 52. longitudinal cylinder; 521. longitudinal slider; 522. longitudinal slide groove; 53. deviation correction motor; 531. transparent base; 6. transverse groove; 61. transverse seat; 62. transverse screw rod; 7. longitudinal groove; 71. longitudinal block; 72. longitudinal screw rod; 8. driving arm; 81. driving gear; 82. driving rack; 83. driving groove; 9. driving motor; 91. forward screw rod; 911. forward slider; 92. reverse screw rod; 921. reverse slider. DETAILED DESCRIPTION

[0033] The following is combined with Figure 1-5 This application is described in further detail.

[0034] The present application embodiment discloses a positioning tool for pole piece CCD detection and correction. Figure 1 , including a base 1, on which a frame 11 is installed. A group of cameras 2 are symmetrically installed on the base 1, and the cameras 2 are slidably connected to the base 1. A transparent bottom plate 3 is installed above the cameras 2, and the transparent bottom plate 3 is used for the camera 2 to shoot the diagonal of the pole piece. A mounting frame 4 is sleeved on the transparent bottom plate 3, and the transparent bottom plate 3 and the mounting frame 4 are glued together. A correction component 5 is installed between the mounting frame 4 and the frame 11, and the correction component 5 is used to drive the mounting frame 4 to move. A group of transparent pressing plates 31 are symmetrically installed above the transparent bottom plate 3, and the transparent pressing plates 31 are used for the camera 2 to shoot the diagonal of the pole piece. The transparent pressing plate 31 is connected to the mounting frame 4 so that the transparent pressing plate 31 moves on the transparent bottom plate 3. First, the transparent pressing plate 31 presses the pole piece on the transparent bottom plate 3 to make the corners of the pole piece flat, and then the camera 2 takes pictures of the diagonal of the pole piece, calculates the deviation value between the pole piece and the standard position, and finally adjusts the position of the mounting frame 4 through the correction drive mechanism so that the deviation value between the pole piece and the standard position is within the specified range. When the pole pieces have different sizes, the position of the camera 2 is moved according to the pole piece sizes so that the pole piece diagonal is located between the transparent pressing plate 31 and the camera 2. This facilitates CCD detection and deflection correction of pole pieces of different sizes, and improves the applicable scope of the pole piece CCD detection and deflection correction positioning mechanism.

[0035] To move Camera 2 on the base, refer to Figure 1 and Figure 2A group of transverse grooves 6 are provided on the base 1 along the length direction of the base 1, and a transverse seat 61 is slidably provided in the transverse groove 6. A transverse screw rod 62 is rotatably provided in the transverse groove 6, and the transverse screw rod 62 is threadedly connected to the transverse seat 61. A longitudinal groove 7 is provided on the top of the transverse seat 61 along the width direction of the base 1, and a longitudinal block 71 is slidably provided in the longitudinal groove 7, and the top of the longitudinal block 71 is fixed to the bottom of the camera 2 by bolts. A longitudinal screw rod 72 is rotatably provided in the longitudinal groove 7, and the longitudinal screw rod 72 is threadedly connected to the longitudinal block 71. The rotation of the longitudinal screw rod 72 drives the longitudinal block 71 to move along the longitudinal groove 7, thereby achieving the effect of moving the camera 2 along the width direction of the base 1. The rotation of the transverse screw rod 62 drives the transverse seat 61 to move along the transverse groove, and the movement of the transverse seat 61 drives the longitudinal block 71 to move, thereby achieving the effect of moving the camera 2 along the length direction of the base 1.

[0036] In order to achieve the effect of pole piece correction, refer to Figure 1 and Figure 3 , a transparent base 531 is installed below the mounting frame 4, and the transparent base 531 is used by the camera 2 to shoot the diagonal of the pole piece. A correction motor 53 is installed in the center of the transparent base 531, and the output shaft of the correction motor 53 is welded to the bottom crossbeam of the mounting frame 4. Transverse slide grooves 512 are provided on both side walls of the transparent base 531, and a transverse slider 511 is slidably arranged in the transverse slide grooves 512. Longitudinal slide grooves 522 are provided on both end walls of the transparent base 531, and a longitudinal slider 521 is slidably arranged in the longitudinal slide grooves 522. The correction assembly 5 includes a group of transverse cylinders 51 and a group of longitudinal cylinders 52, and the transverse cylinders 51 and the longitudinal cylinders 52 are both welded to the frame 11. The output shafts of the transverse cylinders 51 are arranged oppositely, and the output shafts of the transverse cylinders 51 are welded to the back of the transverse slider 511. The output shafts of the longitudinal cylinders 52 are arranged oppositely, and the output shafts of the longitudinal cylinders 52 are welded to the back of the longitudinal slider 521. When the output shaft of one of the transverse cylinders 51 is increased, the output shaft of the other transverse cylinder 51 is shortened, and the transparent base 531 drives the installation frame 4 to move along the length direction of the base 1. At this time, the longitudinal slider 521 moves along the longitudinal slide 522, so that the output shaft of the longitudinal cylinder 52 and the transparent base 531 move relative to each other along the length direction of the base 1, and then the installation frame 4 drives the transparent bottom plate 3 to move along the length direction of the base 1. When the output shaft of one of the longitudinal cylinders 52 is increased, the output shaft of the other longitudinal cylinder 52 is shortened, and the transparent base 531 drives the installation frame 4 to move along the width direction of the base 1. At this time, the transverse slider 511 moves along the transverse slide 512, so that the output shaft of the transverse cylinder 51 and the transparent base 531 move relative to each other along the width direction of the base 1, and then the installation frame 4 drives the transparent bottom plate 3 to move along the width direction of the base 1. When the deviation correction motor 53 is started, the deviation correction motor 53 drives the installation frame 4 to rotate, so that the transparent bottom plate 3 drives the pole piece to move. Through the cooperation of the deviation correction motor 53, the transverse movement cylinder 51 and the longitudinal movement cylinder 52, the transparent bottom plate 3 drives the pole piece to move, thereby achieving the effect of deviation correction of the pole piece.

[0037] In order to make the transparent pressing plate 31 press the pole piece onto the transparent bottom plate 3, refer to Figures 1 to 5 A set of driving grooves 83 are provided at the top of the mounting frame 4, and a driving motor 9 is installed in the driving grooves 83. A forward screw rod 91 is welded on the output shaft of the driving motor 9, and a reverse screw rod 92 is welded on the end of the forward screw rod 91 away from the driving motor 9, and one end of the reverse screw rod 92 is rotatably connected to the inner wall of the driving groove 83. A forward slider 911 is threadedly connected to the forward screw rod 91, and a reverse slider 921 is threadedly connected to the reverse screw rod 92. Both the forward slider 911 and the reverse slider 921 slide in the driving groove 83, and the outer wall of the forward slider 911 and the outer wall of the reverse slider 921 are both fitted with the inner wall of the driving groove 83. A driving rack 82 is installed on the top of the forward slider 911 and the reverse slider 921, and a plurality of driving gears 81 are meshed on the driving rack 82, and a driving arm 8 is welded on the driving gear 81. The driving arms 8 on the forward slider 911 are parallel to each other, and the driving arms 8 on the forward slider 911 are all rotatably connected to the side wall of one of the transparent pressure plates 31; the driving arms 8 on the reverse slider 921 are parallel to each other, and the driving arms 8 on the reverse slider 921 are all rotatably connected to the side wall of the other transparent pressure plate 31. When the driving motor 9 is started, the forward screw rod 91 and the reverse screw rod 92 rotate synchronously. When the forward screw rod 91 rotates, the forward screw rod 91 drives the forward slider 911 to move along the driving groove 83, and the forward slider 911 drives one of the driving racks 82 to move; when the reverse screw rod 92 rotates, the reverse screw rod 92 drives the reverse slider 921 to move along the driving groove 83, and the reverse slider 921 drives the other driving rack 82 to move. When the driving racks 82 approach each other, the driving racks 82 drive the driving gear 81 to rotate, and the rotation of the driving gear 81 drives the driving arm 8 to rotate. The rotation of the driving arm 8 drives the transparent pressure plate 31 to approach each other and move the transparent pressure plate 31 toward the transparent bottom plate 3, thereby achieving the effect that the transparent pressure plate 31 presses the pole piece onto the transparent bottom plate 3.

[0038] The implementation principle of the positioning tool for CCD detection and correction of the pole piece in the embodiment of the present application is as follows: first, according to the size specifications of the pole piece, the lateral screw 62 and the longitudinal screw 72 are rotated to adjust the camera 2 to a suitable position. When the pole piece is located on the transparent bottom plate 3, the drive motor 9 is started, so that the transparent pressure plate 31 presses the pole piece on the transparent bottom plate 3 to achieve the effect of flattening the corners of the pole piece. Then the camera 2 takes a picture of the pole piece diagonally, calculates the deviation value between the pole piece and the standard position, and then drives the pole piece on the transparent bottom plate 3 to move through the cooperation of the correction motor 53, the lateral cylinder 51 and the longitudinal cylinder 52, so that the deviation value between the pole piece and the standard position is within the specified range. When the size specifications of the pole piece are different, the position of the camera 2 is moved according to the size specifications of the pole piece, and the pole piece and the camera 2 are not blocked by the transparent base 531, the transparent bottom plate 3 and the transparent pressure plate 31, so that the pole piece diagonally is located between the transparent pressure plate 31 and the camera 2. It is convenient to carry out CCD detection and correction for pole pieces of different specifications, thereby improving the application scope of the pole piece CCD detection and correction positioning mechanism.

[0039] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A positioning tool for pole piece CCD detection and correction, comprising a base (1), on which a frame (11) is fixedly arranged, characterized in that: A group of cameras (2) are slidably arranged on the base (1), a transparent bottom plate (3) is arranged above the cameras (2), a mounting frame (4) is sleeved on the transparent bottom plate (3), the transparent bottom plate (3) and the mounting frame (4) are fixedly connected, a deviation correction component (5) is arranged between the mounting frame (4) and the frame (11), the deviation correction component (5) is used to drive the mounting frame (4) to move, and a group of transparent pressing plates (31) are movably arranged above the transparent bottom plate (3), and the transparent pressing plates (31) are symmetrically arranged.

2. A positioning tool for pole piece CCD detection and correction according to claim 1, characterized in that: A group of transverse shift grooves (6) are provided on the machine base (1), a transverse shift seat (61) is slidably arranged in the transverse shift grooves (6), the top of the transverse shift seat (61) is connected to the bottom of the camera (2), a transverse shift screw rod (62) is rotatably arranged in the transverse shift grooves (6), and the transverse shift screw rod (62) is threadedly connected to the transverse shift seat (61).

3. A positioning tool for pole piece CCD detection and correction according to claim 2, characterized in that: A longitudinal shift groove (7) is provided on the top of the transverse shift seat (61), a longitudinal shift block (71) is slidably arranged in the longitudinal shift groove (7), the top of the longitudinal shift block (71) is fixedly connected to the bottom of the camera (2), a longitudinal shift screw rod (72) is rotatably arranged in the longitudinal shift groove (7), and the longitudinal shift screw rod (72) is threadedly connected to the longitudinal shift block (71).

4. The positioning tool for pole piece CCD detection and correction according to claim 1, characterized in that: The deviation correction component (5) comprises a group of transverse cylinders (51) and a group of longitudinal cylinders (52); the transverse cylinders (51) are fixedly connected to the frame (11); the output shafts of the transverse cylinders (51) are arranged relative to each other; the output shafts of the transverse cylinders (51) are slidably connected to the side walls of the mounting frame (4); the longitudinal cylinders (52) are fixedly connected to the frame (11); the output shafts of the longitudinal cylinders (52) are arranged relative to each other; the output shafts of the longitudinal cylinders (52) are slidably connected to the end walls of the mounting frame (4).

5. The positioning tool for pole piece CCD detection and correction according to claim 4, characterized in that: A correction motor (53) is fixedly arranged at the bottom of the installation frame (4), and a transparent base (531) is fixedly arranged at the bottom of the correction motor (53). A transverse sliding groove (512) is provided on the side wall of the transparent base (531), and a transverse sliding block (511) is slidably arranged in the transverse sliding groove (512), and the back surface of the transverse sliding block (511) is fixedly connected to the opposite surface of the transverse cylinder (51). A longitudinal sliding groove (522) is provided on the end wall of the transparent base (531), and a longitudinal sliding block (521) is slidably arranged in the longitudinal sliding groove (522), and the back surface of the longitudinal sliding block (521) is fixedly connected to the opposite surface of the longitudinal cylinder (52).

6. The positioning tool for pole piece CCD detection and correction according to claim 1, characterized in that: A group of driving grooves (83) are provided on the top of the installation frame (4), a group of driving racks (82) are slidably arranged in the driving grooves (83), a plurality of driving gears (81) are meshed on the driving racks (82), a driving arm (8) is fixedly arranged on the driving gears (81), and the driving arm (8) is rotatably connected to the side wall of the transparent pressure plate (31).

7. A positioning tool for pole piece CCD detection and correction according to claim 6, characterized in that: A forward screw rod (91) and a reverse screw rod (92) are rotatably arranged in the driving groove (83); the forward screw rod (91) is threadedly connected to a forward slider (911); the forward slider (911) is fixedly connected to one of the driving racks (82); the reverse screw rod (92) is threadedly connected to a reverse slider (921); the reverse slider (921) is fixedly connected to the other driving rack (82).

8. The positioning tool for pole piece CCD detection and correction according to claim 7, characterized in that: A drive motor (9) is fixedly arranged in the drive slot (83); an output shaft of the drive motor (9) is fixedly connected to one end of a forward screw rod (91); the other end of the forward screw rod (91) is fixedly connected to one end of a reverse screw rod (92); and the other end of the reverse screw rod (92) is rotatably connected to the inner wall of the drive slot (83).

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