Coaxial spiral bending equipment for pipes
The coaxial spiral bending device addresses the complexity of existing machines by allowing interchangeable parts and precise control, enhancing accuracy and efficiency in pipe bending operations.
Patent Information
- Application Number
- CN202420936560.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-04-30
AI Technical Summary
Existing spiral pipe bending machines require manual replacement of guide wheels and pressure wheels for different pipe specifications, leading to low bending accuracy and complex operations, which are inadequate for modern industrial high-precision and high-efficiency needs.
A coaxial spiral bending device with a frame, control console, and displacement device that allows for interchangeable bending dies and guide wheels, controlled by a console for different bending radii and angles, ensuring precise pipe clamping and rotation.
Simplifies the operation process and significantly improves bending accuracy by enabling adaptive bending for various pipe sizes and shapes through synchronized movement and clamping mechanisms.
Smart Images
Figure CN222153498U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of coaxial spiral bending equipment for pipes, and in particular to a coaxial spiral bending equipment for pipes. Background Art
[0002] At present, spiral pipe bending machine is a commonly used cold bending equipment for various metal profiles. It is used to spirally bend pipes and can be used to produce spiral coils in heat exchange equipment.
[0003] The spiral pipe bending machine in the related technology includes two rows of guide wheels and a pressure wheel. The pipe passes through the two rows of guide wheels. The pressure wheel is driven by a motor to rotate. The diameter of the spiral circle is adjusted by adjusting the speed of the motor. The pressure wheel is driven by a cylinder to move. By adjusting the stroke of the cylinder, circular, arc or spiral shapes with different curvatures can be obtained.
[0004] With regard to the above-mentioned related technologies, the spiral pipe bending machine can only process products of a single specification. When processing pipes of different specifications, it is necessary to replace the guide wheels and pressure wheels of the corresponding sizes of the pipes, and at the same time, it is necessary to reset the corresponding motor speed and cylinder stroke. The bending accuracy is low and the operation is complicated, which cannot meet the needs of modern industrial production for high-precision and high-efficiency pipe bending. Utility Model Content
[0005] In order to simplify the operation process and improve the bending accuracy of the pipe, the present application provides a pipe coaxial spiral bending device.
[0006] The present application provides a pipe coaxial spiral bending device, which adopts the following technical solution:
[0007] A coaxial spiral bending device for pipes comprises a frame and a control console, wherein the frame is rotatably connected to a rotating seat, the rotating seat is detachably connected to a bending die, a displacement device is provided on the frame, the displacement device is detachably connected to a guide wheel, the displacement device drives the guide wheel to move in a vertical direction, a spiral groove is axially provided on the side wall of the bending die, a circle of guide grooves is provided on the side wall of the guide wheel, the spiral groove and the guide groove are both semicircular and compatible with the pipe, the guide wheel and the bending die cooperate to form a circular channel, the control console is rotatably connected to the frame, and the control console is used to control the operation of the equipment.
[0008] By adopting the above technical solution, different sizes of bending dies and guide wheels are replaced to achieve coaxial spiral bending with different bending radii and different bending angles. The parameters for bending pipes of different sizes are input into the console to control the displacement device to move to the corresponding position, thereby simplifying the operation process. The pipe is clamped between the bending die and the guide wheel, and the motor drives the bending die to rotate, so that the pipe is bent into a spiral coil along the shape of the spiral groove, thereby improving the bending accuracy.
[0009] Optionally, the rotating seat includes a rotating disk, a first mounting seat and a plurality of fixed seats, the rotating disk is rotatably connected to the frame, the lower end surface of the first mounting seat abuts against the upper end surface of the rotating disk, the fixed seat is slidably connected to the rotating disk, the fixed seats are evenly distributed along the circumference of the rotating disk, and one end of the fixed seat close to the axis of the rotating disk abuts against the side wall of the first mounting seat.
[0010] By adopting the above technical solution, a plurality of fixing seats clamp the first mounting seat, so that the fixing seat rotates synchronously with the rotating disk coaxially.
[0011] Optionally, a plurality of first sliding grooves corresponding to the fixed seats are circumferentially formed on the upper end surface of the rotating disk, the extension direction of the first sliding groove is parallel to the radial direction of the rotating disk, the groove width of the first sliding groove gradually decreases from bottom to top, and a first bolt slidably connected to the rotating disk is provided in the first sliding groove, and the end of the first bolt away from the rotating disk passes through the fixed seat and is threadedly connected to the first nut.
[0012] By adopting the above technical solution, the fixed seat moves radially along the rotating disk on the upper end surface of the rotating disk, driving the first bolt to slide in the first sliding groove. When the fixed seat abuts against the first mounting seat, the nut is tightened to fix the fixed seat on the rotating disk. The fixed seat clamps the first mounting seat, making the first mounting seat more stable and improving the bending accuracy of the pipe.
[0013] Optionally, a first fixing block is slidably connected to the fixing seat, the first fixing block is threadedly connected to a first screw rod, the first screw rod is rotatably connected to the fixing seat, and a prismatic column is provided at one end of the first screw rod away from the first mounting seat.
[0014] By adopting the above technical solution, the first screw rotates to drive the first fixing block to abut against the first mounting seat, and a plurality of first fixing blocks clamp the first mounting seat, which further improves the stability of the first mounting seat and improves the bending accuracy of the pipe.
[0015] Optionally, a plurality of second fixed blocks are evenly arranged along the axial direction at one end of the first mounting seat close to the rotating seat, a plurality of second sliding grooves corresponding to the second fixed blocks are circumferentially opened on the upper end surface of the rotating disk, the second sliding grooves extend in the radial direction of the rotating disk, and the groove width of the second sliding grooves gradually decreases from bottom to top. A second bolt slidably connected to the rotating disk is arranged in the second sliding groove, and an end of the second bolt away from the rotating disk passes through the second fixed block and is threadedly connected with a second nut.
[0016] By adopting the above technical solution, the second nut is tightened to fix the second fixing block on the rotating disk. The second fixing blocks are evenly distributed along the axial direction, so that the first mounting seat cannot rotate along its own axis, further improving the stability of the first mounting seat and improving the bending accuracy of the pipe.
[0017] Optionally, a first mounting column is provided on the upper end surface of the first mounting seat, and the first mounting column is inserted in the bending mold. The end of the bending mold away from the rotating disk is rotatably connected with a third bolt, and the threaded end of the third bolt passes through the bending mold and is threadedly connected to the end of the first mounting column away from the first mounting seat.
[0018] By adopting the above technical solution, the bending die is installed on the first mounting seat, the third bolt presses the bending die, and the bending die is fastened to the first mounting seat, thereby improving the stability of the bending die and the bending accuracy of the pipe.
[0019] Optionally, the displacement device includes a vertical moving seat and a horizontal moving seat, the frame is fixedly provided with a sliding rail in the vertical direction, the vertical moving seat is provided with a first sliding block and a second sliding block, the first sliding block is threadedly connected to the second screw, the second screw is rotatably connected to the frame, one end of the second screw is fixedly provided with a first motor, the second sliding block is slidably connected to the corresponding sliding rail, the vertical moving seat is provided with a sliding groove, the horizontal moving seat is provided with a third sliding block which slides in the sliding groove, the third sliding block is threadedly connected to the third screw, the third screw is rotatably connected to the vertical moving seat, one end of the third screw is fixedly provided with a second motor, the third sliding block is penetrated by a guide rod, both ends of the guide rod are fixedly connected to the vertical moving seat, the horizontal moving seat is provided with a hydraulic cylinder on a side away from the vertical moving seat, the hydraulic cylinder is provided with a second mounting seat on an end close to the rotating seat, and the second mounting seat is detachably connected to the guide wheel.
[0020] By adopting the above technical solution, the vertical movable seat and the horizontal movable seat drive the guide wheel to move to the initial position that cooperates with the bending mold. The hydraulic cylinder is used to drive the guide wheel to move up and down during the pipe bending process. Different guide wheels are replaced corresponding to different bending molds to achieve coaxial spiral bending with different bending radii and different bending angles.
[0021] Optionally, a second mounting column is provided on a side of the guide wheel away from the rotating seat, and the end of the second mounting column away from the guide wheel slides in the second mounting seat, and the second mounting seat is inserted with a fourth bolt, the fourth bolt is rotatably connected to the second mounting column, and one end of the fourth bolt extending out of the second mounting seat is threadedly connected to a third nut.
[0022] By adopting the above technical solution, the second bolt passes through the second mounting column and the second mounting seat and is connected to the third nut, thereby reducing the shaking of the guide wheel and making it more convenient to disassemble and assemble the guide wheel.
[0023] In summary, the present application includes at least one of the following beneficial technical effects:
[0024] 1. Replace the bending dies and guide wheels of different sizes to achieve coaxial spiral bending with different bending radii and different bending angles. Input the parameters for bending pipes of different sizes in the console to control the displacement device to move to the corresponding position, which simplifies the operation process. The pipe is clamped between the bending die and the guide wheel. The motor drives the bending die to rotate, so that the pipe is bent into a spiral coil along the shape of the spiral groove, which improves the bending accuracy.
[0025] 2. A plurality of fixing seats clamp the first mounting seat so that the fixing seats rotate synchronously with the coaxial line of the rotating disk;
[0026] 3. The fixed seat moves radially along the rotating disk on the upper end surface of the rotating disk to drive the first bolt to slide in the first sliding groove. When the fixed seat abuts against the first mounting seat, the nut is tightened to fix the fixed seat on the rotating disk. The fixed seat clamps the first mounting seat, making the first mounting seat more stable and improving the bending accuracy of the pipe. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 It is a schematic diagram of the overall structure of the front side of a pipe coaxial spiral bending equipment.
[0028] Figure 2 It is a schematic diagram of the overall structure from the upper side of a pipe coaxial spiral bending device.
[0029] Figure 3 It is a cross-sectional schematic diagram of the first mounting seat and the bending mold.
[0030] Figure 4 It is a cross-sectional schematic diagram of the second mounting seat and the guide wheel.
[0031] Description of reference numerals: 1, frame; 11, sliding rail; 2, control console; 3, rotating seat; 31, rotating disk; 311, first sliding groove; 312, second sliding groove; 32, fixed seat; 321, first bolt; 322, first nut; 323, first fixed block; 324, first screw rod; 325, prismatic column; 33, first mounting seat; 331, second fixed block; 332, second bolt; 333, second nut; 334, first mounting column; 4, bending mold; 41, Spiral groove; 42, third bolt; 5, displacement device; 51, vertical moving seat; 511, first sliding block; 5111, second screw rod; 5112, first motor; 512, second sliding block; 52, horizontal moving seat; 521, third sliding block; 522, third screw rod; 523, second motor; 524, guide rod; 53, hydraulic cylinder; 54, second mounting seat; 541, fourth bolt; 542, third nut; 6, guide wheel; 61, guide groove; 62, second mounting column. DETAILED DESCRIPTION
[0032] The present application is further described in detail below in conjunction with all the accompanying drawings.
[0033] The embodiment of the present application discloses a coaxial spiral bending device for pipes.
[0034] Reference Figure 1 A coaxial spiral bending device for pipes comprises a frame 1, a rotating seat 3 is rotatably connected to the frame 1, and the rotating seat 3 can be driven to rotate by arranging a motor inside the frame 1, the rotating seat 3 comprises a first mounting seat 33, and a bending die 4 is detachably connected to the first mounting seat 33, and coaxial spiral bending with different bending radii and different bending angles can be achieved by replacing the bending die 4, thereby improving the bending accuracy, a displacement device 5 is provided on the frame 1, and a second mounting seat 54 is provided on the displacement device 5, and a guide wheel 6 is detachably connected to the second mounting seat 54, and different bending dies 4 can be adapted by replacing the guide wheel 6, thereby improving the applicability and facilitating the processing of spiral bent pipes of different specifications, the displacement device 5 is used to drive the guide wheel 6 to displace, and a control console 2 is rotatably connected to the upper end surface of the frame 1, and the control console 2 is used to set operating parameters of different bending radii and different bending angles, and after replacing the bending dies 4 and the guide wheels 6 of different sizes, the corresponding parameters can be directly selected on the control console 2 to produce bent pipes, thereby simplifying the operating process.
[0035] Reference Figure 2 and Figure 3 A first mounting post 334 is provided on the upper end surface of the first mounting seat 33, and the first mounting post 334 is inserted in the bending mold 4. The first mounting post 334 can be a prism. The bending mold 4 rotates synchronously with the first mounting seat 33. The end of the bending mold 4 away from the rotating disk 31 is rotatably connected with a third bolt 42. The threaded end of the third bolt 42 passes through the bending mold 4 and is threadedly connected to the end of the first mounting post 334 away from the first mounting seat 33. When in use, the user installs the bending mold 4 on the first mounting seat 33, and the third bolt 42 presses the bending mold 4. The lower end surface of the bending mold 4 is tightly fitted with the upper end surface of the first mounting seat 33, which reduces the situation where the bending mold 4 shakes due to equipment vibration during production, improves the stability of the bending mold 4, and improves the bending accuracy of the pipe.
[0036] Reference Figure 1 and Figure 4A second mounting post 62 is provided on a side of the guide wheel 6 away from the rotating seat 3, and an end of the second mounting post 62 away from the guide wheel 6 is inserted into the second mounting seat 54. The guide wheel 6 is replaced by plugging and unplugging the second mounting post 62. The second mounting seat 54 is inserted with a fourth bolt 541. The threaded end of the fourth bolt 541 passes through the second mounting seat 54 and is threadedly connected to the second mounting post 62 with a third nut 542. The fourth bolt 541 is rotatably connected to the second mounting post 62. When in use, the user tightens the third nut 542 so that both the fourth bolt 541 and the third nut 542 are tightly fitted to the second mounting seat 54, thereby reducing the shaking of the guide wheel 6.
[0037] Reference Figure 1 A spiral groove 41 is provided on the side wall of the bending die 4 along the axial direction, so that the pipe can be bent into a spiral coil along the shape of the spiral groove 41. A circle of guide grooves 61 are provided on the side wall of the guide wheel 6, and the pipe fits with the wall of the guide groove 61. Both the spiral groove 41 and the guide groove 61 are semicircular grooves that match the pipe. The guide wheel 6 and the bending die 4 cooperate to form a circular channel, which fits the pipe just right, reduces the shaking of the pipe, and improves the bending accuracy.
[0038] Reference Figure 1 The displacement device 5 includes a vertical moving seat 51 and a horizontal moving seat 52. In the preparation process before the equipment performs pipe bending, the vertical moving seat 51 drives the guide wheel 6 to move in the vertical direction, and the horizontal moving seat 52 drives the guide wheel 6 to move in the horizontal direction, and finally the guide wheel 6 moves to the corresponding position. A hydraulic cylinder 53 is fixedly connected to the upper end surface of the second mounting seat 54. The hydraulic cylinder 53 is used to drive the guide wheel 6 to move in the vertical direction when performing pipe bending operations. The hydraulic cylinder 53 is fixedly connected to the horizontal moving seat 52.
[0039] Reference Figure 1 and Figure 2 A first sliding block 511 is provided on the vertical movable seat 51, and the first sliding block 511 is threadedly connected to the second screw 5111, and the second screw 5111 is rotatably connected to the frame 1. A first motor 5112 is fixedly provided at one end of the second screw 5111, and the first motor 5112 drives the second screw 5111 to rotate, and the second screw 5111 drives the first sliding block 511 to move vertically along the axis direction of the second screw 5111. A second sliding block 512 is also provided on the vertical movable seat 51, and a sliding rail 11 is fixedly provided on the frame 1 in the vertical direction, and the second sliding block 512 slides on the corresponding sliding rail 11. The sliding rail 11 and the second sliding block 512 improve the stability of the vertical movable seat 51 when it moves in the vertical direction.
[0040] Reference Figure 1 and Figure 2A sliding groove is provided on the vertical movable seat 51, and a third sliding block 521 sliding in the sliding groove is provided on the horizontal movable seat 52. The third sliding block 521 is threadedly connected with a third screw 522. The third screw 522 is rotatably connected to the vertical movable seat 51. A second motor 523 is fixedly provided at one end of the third screw 522. The second motor 523 drives the third screw 522 to rotate. The third screw 522 drives the third sliding block 521 to move horizontally along the axis direction of the third screw 522. A guide rod 524 is passed through the third sliding block 521. Both ends of the guide rod 524 are fixedly connected to the vertical movable seat 51. The guide rod 524 improves the stability of the vertical movable seat 51 when it moves in the horizontal direction.
[0041] Reference Figure 1 and Figure 2 The rotating seat 3 also includes a rotating disk 31 and a plurality of fixed seats 32. The rotating disk 31 is rotatably connected to the frame 1. The upper end surface of the rotating disk 31 is provided with a plurality of first sliding grooves 311 along the circumferential direction. One fixed seat 32 corresponds to two first sliding grooves 311. The extension direction of the first sliding groove 311 is parallel to the radial direction of the rotating disk 31. The fixed seat 32 moves along the radial direction of the rotating disk 31. The first sliding groove 311 is provided with a first bolt 321 slidably connected to the rotating disk 31. The width of the first sliding groove 311 gradually decreases from bottom to top. A bolt 321 will not fall out of the first sliding groove 311 along the axial direction of the rotating disk 31. The end of the first bolt 321 away from the rotating disk 31 passes through the fixed seat 32 and is threadedly connected with the first nut 322. When in use, the first nut 322 is tightened when one end of the fixed seat 32 abuts against the first mounting seat 33. The lower end surface of the first nut 322 abuts against the fixed seat 32, and the fixed seat 32 and the rotating disk 31 are tightly connected. At this time, the fixed seat 32 clamps the first mounting seat 33, and the first mounting seat 33 cannot shake, thereby improving the bending accuracy of the pipe.
[0042] Furthermore, a first fixed block 323 is slidably connected to the fixed seat 32, the first fixed block 323 abuts against the first mounting seat 33, the first fixed block 323 is threadedly connected with a first screw 324, the first screw 324 rotates to drive the first fixed block 323 to be close to the first mounting seat 33, the first screw 324 is rotatably connected to the fixed seat 32, and a prismatic column 325 is provided at one end of the first screw 324 away from the first mounting seat 33. The prismatic column 325 makes it more convenient for the user to use a tool to rotate the first screw 324, thereby further improving the stability of the first mounting seat 33 and improving the bending accuracy of the pipe.
[0043] The second nut 333 is screwed onto the second fixing block 331 and the second fixing block 331 is screwed onto the second fixing block 331.
[0044] The implementation principle of a coaxial spiral bending device for pipes in an embodiment of the present application is as follows: a user installs a first mounting seat 33 on a rotating disk 31, uses a fixed seat 32 to initially abut against the first mounting seat 33, rotates the first screw rod 324 to drive the first mounting block to further abut against the first mounting seat 33, uses bolts and nuts to fix the second mounting block, so that the first mounting seat 33 rotates synchronously with the rotating disk 31 to reduce shaking, installs a bending mold 4 adapted to the pipe on the first mounting seat 33, installs a guide wheel 6 adapted to the pipe on the second mounting seat 54, uses a displacement device 5 to move the guide wheel 6, so that the guide wheel 6 and the bending mold 4 cooperate to form a channel for the pipe to pass through, starts the driving device to drive the rotating disk 31 to rotate, and the pipe is bent along the spiral groove 41 on the bending mold 4, and the hydraulic cylinder 53 drives the guide wheel 6 to move vertically along the axis of the bending mold 4.
[0045] 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 pipe coaxial spiral bending device, comprising a frame (1) and a control console (2), characterized in that: The frame (1) is rotatably connected to a rotating seat (3), the rotating seat (3) is detachably connected to a bending die (4), the frame (1) is provided with a displacement device (5), the displacement device (5) is detachably connected to a guide wheel (6), the displacement device (5) drives the guide wheel (6) to move in a vertical direction, a spiral groove (41) is provided on the side wall of the bending die (4) along the axial direction, a circle of guide grooves (61) is provided on the side wall of the guide wheel (6), the spiral groove (41) and the guide groove (61) are both semicircular and compatible with the pipe, the guide wheel (6) and the bending die (4) cooperate to form a circular channel, and a control console (2) is rotatably connected to the frame (1), and the control console (2) is used to control the operation of the equipment.
2. The coaxial spiral bending device for pipes according to claim 1, characterized in that: The rotating seat (3) comprises a rotating disk (31), a first mounting seat (33) and a plurality of fixed seats (32); the rotating disk (31) is rotatably connected to the frame (1); the lower end surface of the first mounting seat (33) abuts against the upper end surface of the rotating disk (31); the fixed seats (32) are slidably connected to the rotating disk (31); the fixed seats (32) are evenly distributed along the circumference of the rotating disk (31); and one end of the fixed seat (32) close to the axis of the rotating disk (31) abuts against the side wall of the first mounting seat (33).
3. The coaxial spiral bending device for pipes according to claim 2, characterized in that: The upper end surface of the rotating disk (31) is provided with a plurality of first sliding grooves (311) corresponding to the fixed seats (32) along the circumferential direction. The extension direction of the first sliding grooves (311) is parallel to the radial direction of the rotating disk (31). The width of the first sliding grooves (311) gradually decreases from bottom to top. A first bolt (321) slidably connected to the rotating disk (31) is provided in the first sliding groove (311). One end of the first bolt (321) away from the rotating disk (31) passes through the fixed seat (32) and is threadedly connected to a first nut (322).
4. The coaxial spiral bending device for pipes according to claim 2, characterized in that: The fixing seat (32) is slidably connected to a first fixing block (323), the first fixing block (323) is threadedly connected to a first screw rod (324), the first screw rod (324) is rotatably connected to the fixing seat (32), and a prismatic column (325) is provided at one end of the first screw rod (324) away from the first mounting seat (33).
5. The coaxial spiral bending device for pipes according to claim 2, characterized in that: A plurality of second fixing blocks (331) are evenly arranged along the axial direction at one end of the first mounting seat (33) close to the rotating seat (3); a plurality of second sliding grooves (312) corresponding to the second fixing blocks (331) are opened along the circumferential direction on the upper end surface of the rotating disk (31); the second sliding grooves (312) extend in the radial direction of the rotating disk (31); the groove width of the second sliding grooves (312) gradually decreases from bottom to top; a second bolt (332) slidably connected to the rotating disk (31) is arranged in the second sliding groove (312); an end of the second bolt (332) away from the rotating disk (31) passes through the second fixing block (331) and is threadedly connected to a second nut (333).
6. The coaxial spiral bending device for pipes according to claim 2, characterized in that: A first mounting column (334) is provided on the upper end surface of the first mounting seat (33). The first mounting column (334) is inserted into the bending mold (4). An end of the bending mold (4) away from the rotating disk (31) is rotatably connected to a third bolt (42). A threaded end of the third bolt (42) passes through the bending mold (4) and is threadedly connected to an end of the first mounting column (334) away from the first mounting seat (33).
7. The coaxial spiral bending device for pipes according to claim 1, characterized in that: The displacement device (5) comprises a vertical movable seat (51) and a horizontal movable seat (52); a sliding track (11) is fixedly provided on the frame (1) in the vertical direction; a first sliding block (511) and a second sliding block (512) are provided on the vertical movable seat (51); the first sliding block (511) is threadedly connected to a second screw rod (5111); the second screw rod (5111) is rotatably connected to the frame (1); a first motor (5112) is fixedly provided at one end of the second screw rod (5111); the second sliding block (512) is slidably connected to the corresponding sliding track (11); a sliding groove is provided on the vertical movable seat (51); and a sliding groove is provided on the horizontal movable seat (52). A third sliding block (521) slides in the groove, the third sliding block (521) is threadedly connected to a third screw rod (522), the third screw rod (522) is rotatably connected to the vertical movable seat (51), one end of the third screw rod (522) is fixedly provided with a second motor (523), the third sliding block (521) is penetrated by a guide rod (524), both ends of the guide rod (524) are fixedly connected to the vertical movable seat (51), a hydraulic cylinder (53) is provided on a side of the horizontal movable seat (52) away from the vertical movable seat (51), and a second mounting seat (54) is provided on an end of the hydraulic cylinder (53) close to the rotating seat (3), and the second mounting seat (54) is detachably connected to the guide wheel (6).
8. The coaxial spiral bending device for pipes according to claim 7, characterized in that: A second mounting column (62) is provided on a side of the guide wheel (6) away from the rotating seat (3); an end of the second mounting column (62) away from the guide wheel (6) slides in the second mounting seat (54); a fourth bolt (541) is inserted into the second mounting seat (54); the fourth bolt (541) is rotatably connected to the second mounting column (62); and an end of the fourth bolt (541) extending out of the second mounting seat (54) is threadedly connected to a third nut (542).