Emery roll lifting mechanism

Abstract

The utility model discloses an emery roll lifting mechanism, which relates to the technical field of sanders, and comprises a support and an emery roll, the emery roll is positioned below the support, a lifting piece is arranged on one side of the emery roll along the length direction, a positioning block is fixedly arranged on one side of the support, which is provided with the lifting piece, and the positioning block is positioned right above the lifting piece and is horizontally arranged. A first through opening is formed in the positioning block in the vertical direction, a rotating rod is arranged in the first through opening, the rotating rod is rotationally connected with the positioning block, a threaded hole is formed in the rotating rod in the vertical direction, a threaded rod is arranged in the threaded hole, the threaded rod is in threaded connection with the rotating rod in the vertical direction, and the upper end of the threaded rod is sleeved with a threaded sleeve; the lower end of the threaded sleeve is fixedly connected to the upper end of the rotating rod and attached to the upper end of the positioning block, the lifting part is connected to the lower end of the threaded rod, the threaded rod is sleeved with a limiting ring, the upper end of the limiting ring is fixedly connected to the lower end of the rotating rod and horizontally arranged, and the upper end of the limiting ring is attached to the lower end of the positioning block. The emery roll lifting device has the effect of improving the emery roll lifting precision.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of sander technology especially to a sand roller lifting mechanism. BACKGROUND

[0002] At present, when the existing sander compensates for sand belt thread count, compensates for sand belt wear or adjusts the sanding amount of a single roller, most of them adopt manual adjustment, and the operator adjusts the height of the roller by rotating the handle, and the adjusted size needs to be repeatedly corrected with other measuring tools, and the precision is low.

[0003] The related technology discloses a transmission roller with adjustable height from Chinese patent application No.CN219636153U, belonging to the field of transmission roller, including a chassis, a roller body is installed on the chassis through a lifting structure, and the roller body is installed on the lifting structure through a connecting structure, the lifting structure includes a sliding rail, a lifting frame and a sliding block, and the sliding rail is fixed on the chassis. The height of the roller body can be adjusted through the lifting structure, improving the flexibility of the transmission roller. The sliding rail and the sliding block are used with the servo motor, the screw rod and the threaded sleeve, which can ensure stable lifting adjustment of the lifting structure and stable use after adjustment. The connecting structure is used to connect the hexagonal rod and the connecting block through the threaded connection of the connecting bolt, so that the end structure of the roller body can be quickly disassembled, the transmission roller can be easily installed and disassembled, and the stability of the transmission roller can be ensured.

[0004] For the related technology in the above, the device realizes the lifting of the roller through the lead screw. Since the lead screw is used to drive the roller to lift, the lifting amplitude is large each time, and when the roller needs to be accurately lifted, the motor needs to drive the lead screw to rotate repeatedly to reach the specified height, so the lifting precision of the roller is low. UTILITY MODEL CONTENTS

[0005] In order to improve the lifting precision of the sand roller, the application provides a sand roller lifting mechanism.

[0006] The application provides a sand roller lifting mechanism, which adopts the following technical scheme:

[0007] The sand roller lifting mechanism comprises a support and a sand roller, the sand roller is located below the support, the sand roller is horizontally arranged, and the support is used for fixing the sand roller, characterized in that: one side of the sand roller along the length direction is provided with a lifting piece for controlling the sand roller to be lifted or lowered, one side of the support provided with the lifting piece is fixedly provided with a positioning block, the positioning block is located directly above the lifting piece and is horizontally arranged, the positioning block is vertically provided with a first through hole, a rotating rod is arranged in the first through hole, the rotating rod is rotationally connected with the positioning block, the rotating rod is vertically provided with a threaded hole, a threaded rod is arranged in the threaded hole, the threaded rod is vertically and threadedly connected with the rotating rod, a threaded sleeve is arranged on the upper end of the threaded rod, the lower end of the threaded sleeve is fixedly connected with the upper end of the rotating rod and is attached to the upper end of the positioning block, the lifting piece is connected with the lower end of the threaded rod, a limiting ring is arranged on the outer side of the threaded rod, the upper end of the limiting ring is fixedly connected with the lower end of the rotating rod and is horizontally arranged, and the upper end of the limiting ring is attached to the lower end of the positioning block.

[0008] By adopting the above technical scheme, the support is used for supporting the sand roller, the lifting piece drives the sand roller to be lifted or lowered, the threaded sleeve is rotated to drive the rotating rod to rotate, the threaded rod is vertically lifted or lowered, the lifting piece is lifted or lowered by the threaded rod, the limiting ring limits the threaded sleeve, the lower end of the threaded sleeve is attached to the upper end of the positioning block, the threaded rod is slowly lifted or lowered along the vertical direction by rotating the threaded sleeve, the lifting piece drives the sand roller to be slightly lifted or lowered, and the lifting precision of the sand roller is improved.

[0009] Optionally, the sand roller comprises a roller and two eccentric shafts, the two eccentric shafts are connected to the two sides of the roller along the length direction, the lower end of the support is horizontally provided with a second through hole, the eccentric shafts are located in the second through hole and are rotationally connected with the support, and the lifting piece is located at the end of the eccentric shaft away from the roller and is used for driving the eccentric shaft to rotate around the axis thereof.

[0010] By adopting the above technical scheme, the eccentric shafts are connected with the lifting piece through the second through hole, the lifting piece drives the eccentric shafts to rotate, the eccentric shafts and the roller are eccentrically arranged, the eccentric shafts can drive the roller to be lifted or lowered when the eccentric shafts rotate, and the lifting precision of the sand roller is further improved.

[0011] Optionally, a fixing bolt is arranged between the positioning block and the rotating rod, the fixing bolt passes through the positioning block and is attached to the rotating rod, the fixing bolt is threadedly connected with the positioning block, and when the fixing bolt rotates, the fixing bolt can be close to or away from the rotating rod.

[0012] By adopting the above technical scheme, the fixing bolt is rotated, the fixing bolt passes through the positioning block and is attached to the rotating rod, which is conducive to reducing the probability that the rotating rod rotates due to the shaking of the sand roller in the rotating process, and the stability of the sand roller lifting is improved.

[0013] Optionally, a spring is arranged on the outer side of the fixing bolt, the spring is horizontally arranged and is fixedly connected with the positioning block.

[0014] By adopting the above technical solution, when the fixing bolt is in contact with the rotating rod, the spring is in a compressed state; when the fixing bolt is away from the rotating rod, the spring pushes the fixing bolt away from the rotating rod, thus improving the ease of separating the fixing bolt from the rotating rod.

[0015] Optionally, the lifting component includes a lifting cylinder and a swing arm. The lower end of the threaded rod is fixed with a first pin in the vertical direction. The lower end of the first pin is hinged to the upper end of the lifting cylinder in the vertical direction. The output end of the lifting cylinder is fixed with a second pin in the vertical direction. The lower end of the second pin is hinged to one end of the swing arm in the length direction. An eccentric shaft passes through the swing arm and is located in the middle position of the swing arm in the length direction. When the swing arm rotates, it drives the eccentric shaft to rotate.

[0016] By adopting the above technical solution, the threaded rod drives the lifting cylinder to rise and fall through the first pin, and the output end of the lifting cylinder drives the swing arm to rotate through the second pin. The first pin and the second pin cooperate to make the lifting cylinder rotate with the swing arm during the rotation of the swing arm, thereby improving the stability of the sand roller lifting.

[0017] Optionally, a pointer is fixed at the end of the swing arm away from the second pin, an eccentric shaft is located between the pointer and the second pin, and a scale groove is provided at the lower end of the bracket. A scale is provided in the scale groove, and when the swing arm rotates, it drives the pointer to move along the scale.

[0018] By adopting the above technical solution, when the swing arm rotates, the pointer moves along the scale in the scale groove, which can accurately control the height of the sand roller lifting and improve the accuracy of sand roller lifting.

[0019] Optionally, a cylindrical rod is fixed to one end of the fixing bolt near the rotating rod. The cylindrical rod is horizontally positioned. An arc-shaped block is rotatably connected to the other end of the cylindrical rod away from the fixing bolt. The arc-shaped block is horizontally positioned. A circular groove is opened laterally on the side of the arc-shaped block near the cylindrical rod. The cylindrical rod is located in the circular groove and is rotatably connected to the arc-shaped block. An annular protrusion is fixed to the cylindrical rod circumferentially. An annular groove communicating with the circular groove is opened in the arc-shaped block. The annular protrusion is located inside the annular groove.

[0020] By adopting the above technical solution, the rotation of the fixing bolt drives the cylindrical rod to move closer to the rotating rod. The cylindrical rod is located inside the circular groove. The annular protrusion and the annular groove cooperate to limit the arc-shaped block. The fixing bolt drives the arc-shaped block to fit with the rotating rod through the cylindrical rod, which improves the stability of the sand roller lifting.

[0021] Optionally, a moving groove is radially formed on the side of the roller near the eccentric shaft. The moving groove is horizontally set. A positioning screw is rotatably connected to the end of the roller near the eccentric shaft. The positioning screw is horizontally set and passes through the moving groove. The positioning screw is rotatably connected to the roller. A slider is provided in the moving groove. The slider slides along the length of the moving groove. The positioning screw passes through the slider and is threadedly connected to the slider. A nut is sleeved on the outside of the positioning screw. The end of the slider away from the roller is fixedly connected to the eccentric shaft.

[0022] By adopting the above technical solution, the slider drives the eccentric shaft to slide along the length of the moving groove by rotating the positioning screw. The nut fixes the positioning screw, and the slider drives the eccentric shaft to move, which can realize the roller lifting and lowering within a smaller range, thus improving the accuracy of sand roller lifting.

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

[0024] 1. The rotation of the threaded sleeve drives the rotating rod to rotate, causing the threaded rod to rise and fall vertically. The threaded rod drives the lifting component to rise and fall. The limiting ring limits the threaded sleeve, so that the lower end of the threaded sleeve is in contact with the upper end face of the positioning block. By rotating the threaded sleeve, the threaded rod rises and falls slowly vertically, causing the lifting component to drive the sanding roller to rise and fall slightly vertically, thus improving the accuracy of the sanding roller lifting.

[0025] 2. The rotation of the fixing bolt drives the cylindrical rod to move closer to the rotating rod. The annular protrusion and the annular groove cooperate to limit the arc-shaped block. The fixing bolt drives the arc-shaped block to fit against the rotating rod through the cylindrical rod, which improves the stability of the sand roller lifting.

[0026] 3. Rotate the positioning screw to make the slider drive the eccentric shaft to slide along the length of the moving groove. The slider drives the eccentric shaft to move, which can realize the roller lifting and lowering within a smaller range, thus improving the accuracy of sand roller lifting. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of Example 1.

[0028] Figure 2 This is a schematic diagram designed to highlight the internal structure of the positioning block.

[0029] Figure 3 yes Figure 1 An enlarged schematic diagram of part A in the middle.

[0030] Figure 4 This is a schematic diagram of the connection relationship between the positioning screw and the slider in Example 2.

[0031] Figure 5 This is a schematic diagram of the connection relationship between the fixed bolt and the threaded rod in Example 2.

[0032] Figure 6This is a schematic diagram designed to highlight the connection between the cylindrical rod and the fixing bolt.

[0033] Explanation of reference numerals in the attached drawings: 1. Bracket; 11. Positioning block; 12. First opening; 13. Rotating rod; 14. Threaded hole; 15. Threaded rod; 16. Threaded sleeve; 17. Limiting ring; 18. Second opening; 2. Sanding roller; 21. Roller; 22. Eccentric shaft; 221. Moving groove; 222. Positioning screw; 223. Sliding block; 224. Nut; 3. Lifting component; 31. Lifting cylinder; 32. Swing arm; 33. First pin; 34. Second pin; 35. Pointer; 36. Scale; 37. Scale groove; 4. Fixing bolt; 41. Spring; 42. Cylindrical rod; 43. Annular protrusion; 44. Circular groove; 45. Ring groove; 46. Arc block. Detailed Implementation

[0034] The present application will be further described in detail below with reference to all the accompanying drawings.

[0035] This application discloses a sand roller lifting mechanism.

[0036] Example 1

[0037] Reference Figure 1 A sanding roller lifting mechanism includes a support 1 and a sanding roller 2. The sanding roller 2 is located below the support 1 and is horizontally arranged. The support 1 is used to fix the sanding roller 2. A lifting member 3 is provided on one side of the sanding roller 2 along its length direction. The lifting member 3 is used to drive the sanding roller 2 to rise or fall.

[0038] Reference Figure 1 and Figure 2 A positioning block 11 is fixedly provided on one side of the lifting component 3 of the bracket 1. The positioning block 11 is located directly above the lifting component 3 and is horizontally set. The positioning block 11 has a first opening 12 vertically. A rotating rod 13 is provided in the first opening 12. The rotating rod 13 rotates in the first opening 12. A threaded hole 14 is provided in the rotating rod 13 vertically. A threaded rod 15 is provided in the threaded hole 14. The threaded rod 15 is threadedly connected to the rotating rod 13 vertically. A threaded sleeve 16 is fitted on the upper end of the threaded rod 15. The lower end of the threaded sleeve 16 is fixedly connected to the upper end of the rotating rod 13 and fits against the upper end of the positioning block 11. The threaded sleeve 16 drives the rotating rod 13 to rotate, causing the threaded rod 15 to rise and fall vertically. A limiting ring 17 is fitted on the outside of the threaded rod 15. The upper end of the limiting ring 17 is fixedly connected to the lower end of the rotating rod 13 and fits against the positioning block 11. The limiting ring 17 limits the rotating rod 13, so that the rotating rod 13 is in a fixed position during rotation.

[0039] Reference Figure 1 and Figure 3The sanding roller 2 includes a roller 21 and two eccentric shafts 22. The two eccentric shafts 22 are respectively connected to both sides of the roller 21 along its length. The eccentric shafts 22 pass through the swing arm 32. When the swing arm 32 rotates, the roller 21 can be raised or lowered due to the eccentric setting of the eccentric shafts 22 and the roller 21. A pointer 35 is fixed at the end of the swing arm 32 away from the second pin 34. The eccentric shaft 22 is located between the pointer 35 and the second pin 34. A scale groove 37 is opened at the lower end of the bracket 1. A scale 36 is provided in the scale groove 37. The scale 36 corresponds one-to-one with the lifting distance of the roller 21. When the swing arm 32 rotates, the pointer 35 moves along the scale 36 in the scale groove 37. During operation, the operator can adjust the rotation amplitude of the swing arm 32 according to the scale 36, which is conducive to accurately controlling the lifting height of the sanding roller 2 and improving the lifting accuracy of the sanding roller 2.

[0040] Reference Figure 1 The lifting component 3 is connected to the lower end of the threaded rod 15. The lifting component 3 includes a lifting cylinder 31 and a swing arm 32. A first pin 33 is fixed vertically at the lower end of the threaded rod 15. The lower end of the first pin 33 is hinged vertically to the upper end of the lifting cylinder 31. The threaded rod 15 drives the lifting cylinder 31 to rise and fall through the first pin 33. A second pin 34 is fixed vertically at the output end of the lifting cylinder 31. The lower end of the second pin 34 is hinged vertically to one end of the swing arm 32 along its length. The output end of the lifting cylinder 31 is connected through the second pin. 34 drives the swing arm 32 to rotate. The lower end of the bracket 1 has a second opening 18. The sand roller 2 passes through the opening, and the eccentric shaft 22 passes through the swing arm 32 and is located at the center of the swing arm 32 along its length. The threaded rod 15 drives the lifting cylinder 31 to rise and fall through the first pin 33. The output end of the lifting cylinder 31 drives the swing arm 32 to rotate through the second pin 34. The first pin 33 and the second pin 34 cooperate so that during the rotation of the swing arm 32, the lifting cylinder 31 rotates with the swing arm 32, thereby driving the eccentric shaft 22 to rotate.

[0041] Reference Figure 2 and Figure 5 A fixing bolt 4 is provided between the positioning block 11 and the rotating rod 13. The fixing bolt 4 is threadedly connected to the positioning block 11. The fixing bolt 4 can be rotated to move closer to or away from the rotating rod 13. A spring 41 is sleeved on the outside of the fixing bolt 4. The spring 41 is horizontally set and fixedly connected to the positioning block 11. When the fixing bolt 4 is rotated to fit against the rotating rod 13, it limits the rotation of the rotating rod 13. When the fixing bolt 4 moves away from the rotating rod 13, the spring 41 pushes the fixing bolt 4 away from the rotating rod 13, which improves the convenience of adjusting the height of the sanding roller 2.

[0042] The implementation principle of Embodiment 1 of this application is as follows: the threaded sleeve 16 drives the rotating rod 13 to rotate, causing the threaded rod 15 to rise and fall vertically. The threaded rod 15 drives the lifting cylinder 31 to rise and fall through the first pin 33. The output end of the lifting cylinder 31 drives the swing arm 32 to rotate through the second pin 34. The swing arm 32 drives the eccentric shaft 22 to rotate. Since the eccentric shaft 22 is eccentrically set with the roller 21, the rotation of the eccentric shaft 22 drives the roller 21 to rise and fall. By rotating the threaded sleeve 16, the threaded rod 15 rises and falls slowly vertically, causing the swing arm 32 to rotate within a small range. The eccentric shaft 22 drives the roller 21 to rise and fall slightly, improving the lifting accuracy of the sand roller 2.

[0043] Example 2

[0044] Reference Figure 4 The difference between this embodiment and Embodiment 1 is that a moving groove 221 is radially formed on the side of the roller 21 near the eccentric shaft 22. The moving groove 221 is horizontally arranged. A positioning screw 222 is rotatably connected to one end of the roller 21 near the eccentric shaft 22. The positioning screw 222 is horizontally arranged and passes through the moving groove 221. The positioning screw 222 is rotatably connected to the roller 21. A slider 223 is provided in the moving groove 221. The slider 223 can slide along the length of the moving groove 221. The positioning screw 222 passes through the slider 223 and is threadedly connected to the slider 223. Rotation causes slider 223 to slide along the length of moving groove 221. Nut 224 is sleeved on the outside of positioning screw 222. The end of slider 223 away from roller 21 is fixedly connected to eccentric shaft 22. Rotating positioning screw 222 causes slider 223 to drive eccentric shaft 22 to slide along the length of moving groove 221. Nut 224 fixes positioning screw 222. Sliding slider 223 and eccentric shaft 22 can move roller 21 to rise and fall within a smaller range. Adjusting the eccentric distance between eccentric shaft 22 and roller 21 further improves the adjustment accuracy of sand roller 2.

[0045] Reference Figure 5 and Figure 6A cylindrical rod 42 is fixed to one end of the fixing bolt 4 near the rotating rod 13. The cylindrical rod 42 is horizontally positioned. An arc-shaped block 46 is rotatably connected to the end of the cylindrical rod 42 away from the fixing bolt 4. The fixing bolt 4 drives the arc-shaped block 46 to move closer to the moving rod through the cylindrical rod 42. A circular groove 44 is opened laterally on the side of the arc-shaped block 46 near the cylindrical rod 42. The cylindrical rod 42 is located in the circular groove 44. An annular protrusion 43 is fixed circumferentially on the cylindrical rod 42. An annular groove 45 is opened circumferentially inside the annular groove 45. The annular protrusion 43 is located inside the annular groove 45. The rotation of the fixing bolt 4 drives the cylindrical rod 42 to move closer to the rotating rod 13. The cylindrical rod 42 is located inside the circular groove 44. The annular protrusion 43 and the annular groove 45 cooperate to limit the arc-shaped block 46. The fixing bolt 4 drives the arc-shaped block 46 to fit against the rotating rod 13 through the cylindrical rod 42, which helps to improve the fixing effect of the fixing bolt 4 on the rotating rod 13 and improves the stability of the sand roller 2 adjustment.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A sand roll lifting mechanism comprising a support (1) and a sand roll (2), the sand roll (2) being located below the support (1), the sand roll (2) being arranged horizontally, the support (1) being configured to secure the sand roll (2), characterized in that: The sand roller (2) is provided with a lifting piece (3) on one side in the length direction for controlling the lifting or lowering of the sand roller (2), and the support (1) is fixedly provided with a positioning block (11) on one side of the lifting piece (3), the positioning block (11) is located directly above the lifting piece (3) and is horizontally arranged, the positioning block (11) is vertically provided with a first through hole (12), the first through hole (12) is provided with a rotating rod (13), the rotating rod (13) is rotatably connected with the positioning block (11), the rotating rod (13) is vertically provided with a threaded hole (14), the threaded hole (14) is provided with a threaded rod (15), the threaded rod (15) is threadedly connected with the rotating rod (13) in the vertical direction, the threaded rod (15) is provided with a threaded sleeve (16) on the upper end, the threaded sleeve (16) is fixedly connected with the upper end of the rotating rod (13) and is in close contact with the upper end of the positioning block (11), the lifting piece (3) is connected with the lower end of the threaded rod (15), the threaded rod (15) is provided with a limiting ring (17) on the outer side, the limiting ring (17) is fixedly connected with the lower end of the rotating rod (13) and is horizontally arranged, and the upper end of the limiting ring (17) is in close contact with the lower end of the positioning block (11).

2. A sand roll lifting mechanism as claimed in claim 1, wherein: The sand roller (2) includes a roller (21) and two eccentric shafts (22), the two eccentric shafts (22) are respectively connected to the two sides of the roller (21) in the length direction, the support (1) is vertically provided with a second through hole (18) on the lower end, the eccentric shaft (22) is located in the second through hole (18) and is rotatably connected with the support (1), and the lifting piece (3) is located at one end of the eccentric shaft (22) away from the roller (21), and the lifting piece (3) is used for driving the eccentric shaft (22) to rotate around the axis thereof.

3. A sand roll lifting mechanism as claimed in claim 1, wherein: The positioning block (11) and the rotating rod (13) are provided with a fixing bolt (4), the fixing bolt (4) penetrates through the positioning block (11) and is in close contact with the rotating rod (13), the fixing bolt (4) is threadedly connected with the positioning block (11), and when the fixing bolt (4) rotates, the fixing bolt (4) can be close to or away from the rotating rod (13).

4. A sand roll lifting mechanism as claimed in claim 3, wherein: The fixing bolt (4) is provided with a spring (41) on the outer side, and the spring (41) is horizontally arranged and fixedly connected with the positioning block (11).

5. A sand roll lifting mechanism as claimed in claim 1, wherein: The lifting piece (3) includes a lifting cylinder (31) and a swing arm (32), the lower end of the threaded rod (15) is fixedly provided with a first pin shaft (33) in the vertical direction, the lower end of the first pin shaft (33) is hingedly connected with the upper end of the lifting cylinder (31) in the vertical direction, the output end of the lifting cylinder (31) is fixedly provided with a second pin shaft (34) in the vertical direction, the lower end of the second pin shaft (34) is hingedly connected with one end of the swing arm (32) in the vertical direction, the eccentric shaft (22) penetrates through the swing arm (32) and is located at the middle position of the swing arm (32) in the length direction, and when the swing arm (32) rotates, the eccentric shaft (22) is driven to rotate.

6. A sand roll lifting mechanism as claimed in claim 5, wherein: The pointer (35) is arranged at one end of the swing arm (32) away from the second pin shaft (34), the eccentric shaft (22) is arranged between the pointer (35) and the second pin shaft (34), the bracket (1) is provided with a scale groove (37) at the lower end, and the scale groove (37) is provided with a scale table (36); when the swing arm (32) rotates, the pointer (35) is driven to move along the scale table (36).

7. A sand roll lifting mechanism as claimed in claim 3, wherein: The cylindrical rod (42) is arranged at one end of the fixing bolt (4) close to the rotating rod (13), the cylindrical rod (42) is horizontally arranged, the arc-shaped block (46) is rotatably connected to one end of the cylindrical rod (42) away from the fixing bolt (4), the arc-shaped block (46) is horizontally arranged, the circular groove (44) is arranged on one side of the arc-shaped block (46) close to the cylindrical rod (42) in the transverse direction, the cylindrical rod (42) is arranged in the circular groove (44) and is rotatably connected to the arc-shaped block (46), the annular protrusion (43) is arranged on the cylindrical rod (42) in the circumferential direction, the annular groove (45) is arranged in the arc-shaped block (46) and is communicated with the circular groove (44), and the annular protrusion (43) is arranged in the annular groove (45).

8. A sand roll lifting mechanism as claimed in claim 2, wherein: The roller (21) is provided with the moving groove (221) on one side close to the eccentric shaft (22) in the radial direction, the moving groove (221) is horizontally arranged, the positioning screw rod (222) is rotatably connected to one end of the roller (21) close to the eccentric shaft (22), the positioning screw rod (222) is horizontally arranged and penetrates through the moving groove (221), the positioning screw rod (222) is rotatably connected to the roller (21), the sliding block (223) is arranged in the moving groove (221), the sliding block (223) slides along the length direction of the moving groove (221), the positioning screw rod (222) penetrates through the sliding block (223) and is threadedly connected to the sliding block (223), the nut (224) is arranged outside the positioning screw rod (222), and one end of the sliding block (223) away from the roller (21) is fixedly connected to the eccentric shaft (22).

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