Chamfered belt tensioner

Abstract

This invention belongs to the field of gypsum board production technology and discloses a chamfered belt tensioning device, comprising: a fixed roller, at least one fixed roller is arranged below the forming belt along a direction perpendicular to the conveying direction of the forming belt; a tensioning roller, a tensioning roller is arranged below the fixed roller, the tensioning roller and the fixed roller are arranged parallel to each other, and the chamfered belt is wound and passed through the tensioning roller and each fixed roller; a displacement driving component is connected to the tensioning roller, the displacement driving component can drive the tensioning roller to move along a direction parallel to the conveying direction of the forming belt, so that the tensioning roller drives the chamfered belt to move, thereby tensioning the chamfered belt. This invention achieves rapid tensioning of the chamfered belt by winding the chamfered belt through the tensioning roller and each fixed roller, and by driving the tensioning roller to move along the conveying direction of the forming belt through the displacement driving component, adjusting the distance between the tensioning roller and the fixed roller, and stretching the chamfered belt, without the need for manual adjustment, thus simplifying the operation process.

Description

Technical Field

[0001] This invention relates to the field of gypsum board production technology, specifically to a chamfered belt tensioning device. Background Technology

[0002] In the gypsum board production process, in order to facilitate subsequent construction and splicing, the sides of the gypsum board blank need to be processed into wedges (bevels) while it is wet. The industry generally uses bevel belts to achieve this process: the bevel belt is tightly fitted on the outside of the forming belt that transports the gypsum board blank, and is directly driven by the forming belt, moving synchronously with the gypsum board blank, thereby continuously extruding and forming the wet board sides.

[0003] After a certain number of years of use, the chamfered belt will gradually loosen. In order to tighten the loose chamfered belt, the industry generally adopts a manual adjustment method to tighten the chamfered belt. That is, the chamfered belt is wound around the forming belt and the tensioning roller at the same time. By manually adjusting the position of the tensioning roller, the chamfered belt is stretched to achieve tension.

[0004] The existing manual adjustment method is cumbersome and inefficient, making it difficult to meet the needs of large-scale gypsum board production. Summary of the Invention

[0005] To address this issue, the present invention provides a chamfered belt tensioning device to solve the problem of cumbersome operation caused by the manual adjustment method in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0007] A chamfered belt tensioning device, comprising:

[0008] At least one fixed roller is provided below the forming belt along a direction perpendicular to the conveying direction of the forming belt;

[0009] A tensioning roller is provided below the fixed roller, and the tensioning roller is arranged parallel to the fixed roller. A chamfered belt is wound and passed through the tensioning roller and each of the fixed rollers.

[0010] A displacement drive assembly is connected to the tension roller. The displacement drive device can drive the tension roller to move along a direction parallel to the conveying direction of the forming belt, so that the tension roller drives the chamfered belt to move and tension the chamfered belt.

[0011] Furthermore, the displacement driving component includes:

[0012] An end connecting plate is fixedly installed at each end of the tension roller. The two end connecting plates are arranged in parallel, and the bottom of both end connecting plates protrudes from the bottom of the tension roller.

[0013] A translational connecting frame is provided below the tensioning roller, and the two ends of the translational connecting frame are respectively fixedly connected to the inner side of the two end connecting plates near the bottom.

[0014] A driving device is connected to the translation connecting frame, and the driving device drives the translation connecting frame to move horizontally, thereby driving the tension roller to move horizontally.

[0015] Furthermore, the driving device includes:

[0016] A threaded plate holder, which is fixedly connected to the bottom of the translational connecting frame;

[0017] A ball screw, one end of which passes through the threaded plate holder and is threadedly connected to the threaded plate holder;

[0018] A stepper motor, wherein the drive end of the stepper motor is connected to the other end of the ball screw via a coupling;

[0019] The stepper motor drives the ball screw to rotate, and the ball screw is threadedly engaged with the threaded plate seat, so that the threaded plate seat moves along the length direction of the ball screw. The threaded plate seat drives the translational connecting frame to move, and the two end connecting plates and the tensioning roller move synchronously.

[0020] Furthermore, it also includes a mounting bracket, which has two rectangular frames arranged vertically and parallel to each other, and a plurality of connecting columns arranged vertically between the two rectangular frames to connect the two rectangular frames;

[0021] An installation area is formed between the two rectangular frames;

[0022] The tensioning rollers are installed within the installation area, and each of the fixed rollers is installed on top of the rectangular frame above.

[0023] Furthermore, at the top of two of the sides of the lower rectangular frame, an upper protrusion is provided along the length of the side.

[0024] The bottom of the two end connecting plates is provided with a groove, and the upper protrusion can be engaged in the groove;

[0025] The two end connecting plates are respectively installed on the two side frames by engaging with the upper protrusion rod through the groove.

[0026] Furthermore, a support plate is installed at both ends of each of the fixed rollers, and the bottom of each support plate is fixedly connected to the top of the frame of the rectangular frame above.

[0027] Each of the support plates is rotatably connected to the corresponding fixed roller.

[0028] Furthermore, the tensioning roller is a hollow cylindrical structure with closed ends. The tensioning roller has a long opening along its length, and the long opening is directly opposite the winding position of the chamfered belt on the tensioning roller.

[0029] Furthermore, a movable roller is provided inside the tension roller along its length, and the movable roller is directly opposite the long opening;

[0030] The movable roller is capable of moving in a straight line and passing through the long opening of the tension roller to push the chamfered belt away from the tension roller to tension the chamfered belt.

[0031] Furthermore, it also includes a linear drive assembly for driving the moving roller in a linear motion;

[0032] The linear drive component includes:

[0033] A sliding rod is connected to each end of the moving roller;

[0034] The connecting rod has its two ends connected to the inner sides of the two sliding rods respectively;

[0035] A drive cylinder is disposed inside the moving roller. The drive end of the drive cylinder is fixedly connected to a drive shaft, and the end of the drive shaft away from the drive cylinder is fixedly connected to the connecting rod.

[0036] The movable roller is rotatably connected to the two sliding rods.

[0037] Furthermore, a support seat is provided inside the tensioning roller at a position directly opposite the long opening, and the drive cylinder is installed on the side of the support seat directly opposite the long opening;

[0038] Sliding grooves are provided at both ends of the tension roller opposite to the sliding rods along the moving direction of the moving roller, and the two sliding rods are slidably embedded in the corresponding sliding grooves.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] This invention achieves rapid tensioning of the chamfered belt by winding the chamfered belt around the tension roller and each fixed roller, and by using a displacement drive component to move the tension roller along the conveying direction of the forming belt, thereby adjusting the distance between the tension roller and the fixed rollers and stretching the chamfered belt. This eliminates the need for manual adjustment and simplifies the operation process. Attached Figure Description

[0041] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the overall structure of a chamfered belt tensioning device provided in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the overall structure of the tensioning roller and displacement drive assembly in an embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of the overall structure of the moving roller and linear drive assembly in an embodiment of the present invention.

[0045] The labels in the diagram represent the following:

[0046] 1. Fixed roller; 2. Tensioning roller; 3. Chamfered belt; 4. Displacement drive assembly; 5. Mounting bracket; 6. Support plate; 7. Long opening; 8. Moving roller; 9. Linear drive assembly; 10. Bearing seat; 11. Slide groove; 12. First bearing; 13. Second bearing;

[0047] 401. End connecting plate; 402. Translation connecting frame; 403. Drive device; 404. Groove;

[0048] 501. Rectangular frame; 502. Connecting column; 503. Upper protruding rod;

[0049] 901. Sliding rod; 902. Connecting rod; 903. Drive cylinder;

[0050] 4031, threaded plate holder; 4032, ball screw; 4033, stepper motor. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] like Figure 1 , Figure 2 As shown, the present invention provides a chamfered belt tensioning device, comprising:

[0053] Fixed roller 1, at least one fixed roller 1 is placed below the forming belt along the direction perpendicular to the conveying direction of the forming belt;

[0054] Tensioning roller 2 is set below the fixed roller 1. The tensioning roller 2 is set parallel to the fixed roller 1. The chamfered belt 3 is wound and passed through the tensioning roller 2 and each fixed roller 1.

[0055] The displacement drive assembly 4 is connected to the tension roller 2. The displacement drive device 403 can drive the tension roller 2 to move along a direction parallel to the forming belt conveying direction, so that the tension roller 2 drives the chamfered belt 3 to move, thereby tensioning the chamfered belt 3.

[0056] This invention achieves rapid tensioning of the chamfered belt 3 by winding the chamfered belt 3 around the tension roller 2 and each fixed roller 1, and by using the displacement drive component 4 to move the tension roller 2 along the conveying direction of the forming belt, thereby adjusting the distance between the tension roller 2 and the fixed roller 1 and stretching the chamfered belt 3. This eliminates the need for manual adjustment and simplifies the operation process.

[0057] This embodiment provides a chamfered belt tensioning device, mainly for the automatic adjustment technology of the chamfered belt 3 in the gypsum board production process.

[0058] like Figure 1 As shown, specifically, a row of fixed rollers 1 is set below the forming belt (the number of fixed rollers 1 can be determined according to the actual application scenario). A tension roller 2 is set below the row of fixed rollers 1. A chamfered belt 3 is sleeved on the forming belt. The side of the chamfered belt 3 located on the lower side of the forming belt is wrapped around the tension roller 2 and each fixed roller 1. The tension roller 2 is driven to move parallel by the displacement drive component 4, and the distance between the tension roller 2 and the fixed roller 1 is adjusted. The length of the chamfered belt 3 between the tension roller 2 and the fixed roller 1 is also changed accordingly, thereby adjusting the remaining length of the chamfered belt 3 sleeved on the forming belt. When the chamfered belt 3 is slack, the position of the tension roller 2 is adjusted so that the chamfered belt 3 is tightly sleeved on the forming belt.

[0059] The chamfered belt 3 is wound around the tension roller 2 and the fixed roller 1 in the radial direction.

[0060] like Figure 2 As shown, the displacement drive assembly 4 is used to drive the tension roller 2 to move linearly along the direction parallel to the forming belt conveying direction. The displacement drive assembly 4 includes:

[0061] End connecting plate 401: One end connecting plate 401 is fixedly installed at each end of the tension roller 2. The two end connecting plates 401 are arranged in parallel, and the bottom of both end connecting plates 401 protrudes from the bottom of the tension roller 2.

[0062] A translational connecting frame 402 is provided below the tensioning roller 2. The two ends of the translational connecting frame 402 are respectively fixedly connected to the inner side of the two end connecting plates 401 near the bottom.

[0063] The drive unit 403 is connected to the translation connecting frame 402. The drive unit 403 drives the translation connecting frame 402 to move horizontally, thereby driving the tension roller 2 to move horizontally.

[0064] The drive unit 403 is connected to the tension roller 2 via the translation connecting frame 402 and the two end connecting plates 401, and drives the tension roller 2 to move.

[0065] The drive unit 403 includes:

[0066] Threaded plate holder 4031 is fixedly connected to the bottom of translational connecting frame 402;

[0067] The ball screw 4032 has one end passing through the threaded plate seat 4031 and being threadedly connected to the threaded plate seat 4031;

[0068] Stepper motor 4033, the drive end of stepper motor 4033 is connected to the other end of ball screw 4032 via a coupling;

[0069] Stepper motor 4033 drives ball screw 4032 to rotate. Ball screw 4032 is threadedly engaged with threaded plate holder 4031, causing threaded plate holder 4031 to move along the length of ball screw 4032. Threaded plate holder 4031 drives translational connecting frame 402 to move, and the two end connecting plates 401 and tension roller 2 move synchronously.

[0070] like Figure 1 As shown, in order to enable the fixed roller 1 to be installed above the tension roller 2, a mounting bracket 5 is also included. The mounting bracket 5 has two rectangular frames 501 arranged vertically and parallel to each other, and a plurality of connecting columns 502 arranged vertically between the two rectangular frames 501 to connect the two rectangular frames 501.

[0071] An installation area is formed between the two rectangular frames 501;

[0072] Tensioning rollers 2 are installed in the installation area, and each fixed roller 1 is installed on top of the rectangular frame 501 above.

[0073] The top end of each connecting post 502 is connected to the bottom end of the upper rectangular frame 501, and the bottom end of each connecting post 502 is connected to the top end of the lower rectangular frame 501. The height of the installation area is determined by the length of the connecting post 502. The connecting post 502 is set to a suitable length according to the size (thickness) of the tension roller 2 so that the installation area can accommodate the tension roller 2.

[0074] In order not to affect the linear movement of the tension roller 2, each connecting post 502 is connected to the corner of the upper and lower rectangular frames 501.

[0075] To ensure the stability of the device during operation, the mounting bracket 5 is fixedly installed below the forming belt.

[0076] The chamfered belt 3, located below the forming belt, passes around the tension roller 2 and the fixed roller 1 in sequence, forming a "Z" shape between the tension roller 2 and the fixed roller 1.

[0077] In order to install the tension roller 2, upper protrusions 503 are provided on the top of two of the sides of the lower rectangular frame 501 along the length of the side.

[0078] The bottom of the two end connecting plates 401 is provided with a groove 404, and the upper protrusion 503 can be engaged in the groove 404;

[0079] The two end connecting plates 401 are respectively installed on the two side frames by engaging with the upper protrusion rod 503 through the groove 404.

[0080] The tension roller 2 is slidably connected to the rectangular frame 501 below through the end connecting plates 401 at both ends, making the tension roller 2 more stable during parallel movement. When the stepper motor 4033 drives the tension roller 2 to move, the tension roller 2 moves along the length direction of the two side frames (that is, moves parallel to the conveying direction of the forming belt).

[0081] In order to install the fixed roller 1, a support plate 6 is installed at both ends of each fixed roller 1, and the bottom of each support plate 6 is fixedly connected to the top of the frame of the upper rectangular frame 501.

[0082] Each support plate 6 is rotatably connected to the corresponding fixed roller 1.

[0083] The fixed roller 1 is rotated so that it can rotate under the drive of the chamfering belt 3, thereby reducing the friction between the chamfering belt 3 and the fixed roller 1 and reducing the resistance of the chamfering belt 3 as it rotates with the forming belt.

[0084] In order to enable the fixed roller 1 to be rotatably mounted on the support plate 6, a circular hole is provided on each support plate 6, and a first bearing 12 is fixedly installed in the circular hole. The two ends of the fixed roller 1 are respectively fixedly connected to the inner ring of the corresponding first bearing 12.

[0085] like Figure 1 , Figure 2 , Figure 3As shown, in order to further achieve tensioning of the chamfered belt 3, the present invention also makes the following design: Specifically, the tensioning roller 2 is a cylindrical structure with a hollow interior and closed ends. The tensioning roller 2 is provided with a long opening 7 along its length direction, and the long opening 7 is directly opposite the winding position of the chamfered belt 3 on the tensioning roller 2.

[0086] Inside the tension roller 2, a movable roller 8 is arranged along its length, with the movable roller 8 directly facing the long opening 7;

[0087] The movable roller 8 can move in a straight line and pass through the long opening 7 to the tension roller 2, so as to push the chamfered belt 3 to move away from the tension roller 2 and to tension the chamfered belt 3.

[0088] When the position of the tension roller 2 is adjusted to the limit by the stepper motor 4033, the moving roller 8 can be controlled to extend out of the tension roller 2. When the moving roller 8 extends out of the tension roller 2, it can push the chamfered belt 3 away from the tension roller 2 from the long opening 7, and further adjust the length of the chamfered belt 3 between the moving roller 8 and the fixed roller 1.

[0089] The chamfered belt 3 is wound around the long opening 7 of the tension roller 2. In order to prevent the edge of the long opening 7 from scraping the chamfered belt 3 when it rotates, the edge of the long opening 7 is set to a smooth arc surface.

[0090] like Figure 3 As shown, in order to drive the moving roller 8 to move linearly, a linear drive assembly 9 is also included, which is used to drive the moving roller 8 to move linearly.

[0091] Linear drive component 9 includes:

[0092] A sliding rod 901 is connected to each end of the moving roller 8;

[0093] Connecting rod 902, with its two ends connected to the inner sides of two sliding rods 901 respectively;

[0094] A drive cylinder 903 is installed inside the moving roller 8. The drive end of the drive cylinder 903 is fixedly connected to a drive shaft, and the end of the drive shaft away from the drive cylinder 903 is fixedly connected to a connecting rod 902.

[0095] The movable roller 8 is rotatably connected to two sliding rods 901.

[0096] The drive cylinder 903 controls the extension of the drive shaft, which drives the connecting rod 902 and the sliding rod 901 to move linearly, thereby driving the moving roller 8 to move linearly, so that the moving roller 8 extends the tension roller 2 from the long opening 7, and then the moving roller 8 drives the chamfered belt 3 to move.

[0097] The movable roller 8 is rotated so that it can rotate under the drive of the chamfering belt 3, thereby reducing the friction between the chamfering belt 3 and the movable roller 8 and reducing the resistance of the chamfering belt 3 as it rotates with the forming belt.

[0098] In order to enable the movable roller 8 to be rotatably mounted on the sliding rod 901, a through hole is provided on each sliding rod 901, and a second bearing 13 is fixedly installed in the through hole. The two ends of the movable roller 8 are respectively fixedly connected to the inner ring of the corresponding second bearing 13.

[0099] In order to fix the drive cylinder 903, a support seat 10 is provided inside the tension roller 2 at a position directly opposite the long opening 7, and the drive cylinder 903 is installed on the side of the support seat 10 directly opposite the long opening 7.

[0100] Slide grooves 11 are provided at both ends of the tension roller 2 opposite to the sliding rods 901 along the moving direction of the moving roller 8, and the two sliding rods 901 are slidably embedded in the corresponding slide grooves 11.

[0101] Two sliding rods 901 are slidably embedded in the slide groove 11. The sliding rods 901 move along the slide groove 11 to ensure the smoothness of the linear movement of the moving rod.

[0102] The stroke of the drive cylinder 903 is sufficient to drive the moving roller 8 to extend out of the tension roller 2.

[0103] When using this device, first put the chamfered belt 3 on the forming belt, and place the chamfered belt 3 on the side below the forming belt, and wrap it around the radial outside of each fixed roller 1 and tension roller 2.

[0104] When the chamfer belt 3 becomes loose, the stepper motor 4033 is started. The stepper motor 4033 drives the ball screw 4032 to rotate. The ball screw 4032 drives the threaded plate seat 4031 to move linearly. The threaded plate seat 4031 drives the tension roller 2 to move through the translation connecting frame 402 and the end connecting plate 401. The length of the chamfer belt 3 between the tension roller 2 and the fixed roller 1 is stretched, thus tightening the chamfer belt 3.

[0105] When the stepper motor 4033 reaches its limit, the chamfered belt 3 is still slack. The drive cylinder 903 is activated, which drives the drive shaft to extend. The drive shaft pushes the connecting rod 902 and the sliding rod 901 to move linearly, which in turn drives the moving roller 8 to move linearly. The moving roller 8 passes through the tensioning roller 2 from the long opening 7. The extended moving roller 8 presses against the chamfered belt 3 and pushes the chamfered belt 3 to move away from the tensioning roller 2, thus tensioning the chamfered belt 3 a second time.

[0106] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A chamfered belt tensioning device, characterized in that, have: At least one fixed roller (1) is provided below the forming belt along the conveying direction perpendicular to the forming belt. Tensioning roller (2), a tensioning roller (2) is provided below the fixed roller (1), the tensioning roller (2) is arranged parallel to the fixed roller (1), and a chamfered belt (3) is wound and passed through the tensioning roller (2) and each of the fixed rollers (1). The displacement drive assembly (4) is connected to the tension roller (2). The displacement drive device (403) can drive the tension roller (2) to move in a direction parallel to the forming belt conveying direction, so that the tension roller (2) drives the chamfered belt (3) to move, so as to tension the chamfered belt (3).

2. The chamfered belt tensioning device according to claim 1, characterized in that, The displacement driving component (4) includes: An end connecting plate (401) is fixedly installed at each end of the tension roller (2). The two end connecting plates (401) are arranged in parallel, and the bottom of the two end connecting plates (401) protrudes from the bottom of the tension roller (2). A translational connecting frame (402) is provided below the tensioning roller (2), and the two ends of the translational connecting frame (402) are respectively fixedly connected to the inner side of the two end connecting plates (401) near the bottom; A drive device (403) is connected to the translation connecting frame (402). The drive device (403) drives the translation connecting frame (402) to move horizontally, thereby driving the tension roller (2) to move horizontally.

3. The chamfered belt tensioning device according to claim 2, characterized in that, The drive device (403) includes: Threaded plate holder (4031), the threaded plate holder (4031) is fixedly connected to the bottom of the translational connecting frame (402); A ball screw (4032) has one end passing through the threaded plate seat (4031) and threadedly connected to the threaded plate seat (4031); A stepper motor (4033) is provided, the drive end of which is connected to the other end of the ball screw (4032) via a coupling. The stepper motor (4033) drives the ball screw (4032) to rotate. The ball screw (4032) is threadedly engaged with the threaded plate holder (4031), causing the threaded plate holder (4031) to move along the length direction of the ball screw (4032). The threaded plate holder (4031) drives the translational connecting frame (402) to move, and the two end connecting plates (401) and the tensioning roller (2) move synchronously.

4. A chamfered belt tensioning device according to claim 2, characterized in that, It also includes a mounting bracket (5), which has two rectangular frames (501) arranged vertically and parallel to each other, and a plurality of connecting columns (502) arranged vertically between the two rectangular frames (501) to connect the two rectangular frames (501). An installation area is formed between the two rectangular frames (501); The tensioning roller (2) is installed in the installation area, and each of the fixed rollers (1) is installed on top of the rectangular frame (501) above.

5. A chamfered belt tensioning device according to claim 4, characterized in that, The top of two of the sides of the rectangular frame (501) below are provided with upper protruding rods (503) along the length of the sides. The bottom of the two end connecting plates (401) is provided with a groove (404), and the upper protrusion (503) can be engaged in the groove (404); The two end connecting plates (401) are respectively installed on the two side frames by engaging with the upper protrusion (503) through the groove (404).

6. A chamfered belt tensioning device according to claim 4, characterized in that, A support plate (6) is installed at both ends of each of the fixed rollers (1), and the bottom of each support plate (6) is fixedly connected to the top of the frame of the rectangular frame (501) above. Each of the support plates (6) is rotatably connected to the corresponding fixed roller (1).

7. A chamfered belt tensioning device according to claim 1, characterized in that, The tension roller (2) is a hollow cylindrical structure with closed ends. The tension roller (2) has a long opening (7) along its length, and the long opening (7) is directly opposite to the winding position of the chamfered belt (3) on the tension roller (2).

8. A chamfered belt tensioning device according to claim 7, characterized in that, A movable roller (8) is provided inside the tension roller (2) along its length, and the movable roller (8) is directly opposite the long opening (7). The movable roller (8) can move in a straight line and pass through the tension roller (2) through the long opening (7) to push the chamfered belt (3) to move away from the tension roller (2) to tension the chamfered belt (3).

9. A chamfered belt tensioning device according to claim 8, characterized in that, It also includes a linear drive assembly (9) for driving the moving roller (8) to linear motion; The linear drive component (9) includes: A sliding rod (901) is connected to each end of the moving roller (8). The connecting rod (902) is connected at both ends to the inner sides of the two sliding rods (901); A drive cylinder (903) is disposed inside the moving roller (8). The drive end of the drive cylinder (903) is fixedly connected to a drive shaft, and the end of the drive shaft away from the drive cylinder (903) is fixedly connected to the connecting rod (902). The movable roller (8) is rotatably connected to the two sliding rods (901).

10. A chamfered belt tensioning device according to claim 9, characterized in that, A support seat (10) is provided inside the tension roller (2) at a position directly opposite the long opening (7), and the drive cylinder (903) is installed on the side of the support seat (10) directly opposite the long opening (7); Slide grooves (11) are provided on both ends of the tension roller (2) opposite to the sliding rod (901) along the moving direction of the moving roller (8), and the two sliding rods (901) are slidably embedded in the corresponding slide grooves (11).

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