CN219766455U - Rebound-proof plate bending machine - Google Patents

Abstract

The utility model discloses an anti-rebound plate bending machine, and belongs to the technical field of plate processing. The rolling machine comprises a workbench, wherein a supporting frame and a first lifting mechanism are arranged on the workbench, the first lifting mechanism is connected with a rolling plate mechanism, and a roll shaft assembly and an anti-rebound mechanism are arranged above the rolling plate mechanism. The utility model solves the problem of poor service performance of the existing veneer reeling machine, the inner wall of the supporting column is provided with the first chute and the second chute, the electric push rod rolls in the first chute by the aid of the first ball when pushing the transverse plate to lift, and the air cylinder rolls in the second chute by the aid of the second ball when driving the installation cavity to lift, so that shaking is avoided during lifting; the mounting cavity is driven to lift by the air cylinder until the roller contacts the surface of the coiled plate to press and prevent rebound; starting the double-shaft motor to drive the clamping blocks to move in opposite directions until the clamping blocks are close to two sides of the coiled plate to limit, dislocation at two ends of the coiled plate is prevented, and the usability of the existing veneer reeling machine is improved.

Description

Rebound-proof plate bending machine

Technical Field

The utility model relates to the technical field of plate processing, in particular to an anti-rebound plate bending machine.

Background

The veneer reeling machine is a device for bending and forming a plate by using a working roll, can form parts with different shapes such as a cylindrical part, a conical part and the like, and is very important processing equipment; the working principle of the plate bending machine is that the working roller moves under the action of external forces such as hydraulic force, mechanical force and the like, so that the plate is bent or rolled for forming.

The publication number is: chinese patent CN212551145U discloses an anti-rebound veneer reeling machine. The utility model mainly solves the defect that the existing plate is easy to rebound after being rolled, which leads to the larger gaps and dislocation at the two ends of the plate. The patent always keeps rolling down one end surface of the plate rolled by the fixed roller and the movable roller through the control pressing plate and the roller, and one end of the plate is prevented from rebounding after being rolled. Although the problem of easy rebound of the coiled plate is solved in the above patent, in actual operation and use, the following two defects still exist:

in the prior art, the distance between the movable roller and the fixed roller is regulated through the hydraulic cylinder, the distance between the pressing plate and the rolling wheel and the plate is regulated through the electric telescopic rod, and the hydraulic cylinder and the electric telescopic rod respectively control the movable roller and the fixed roller and the rolling wheel and the two ends of the plate are not provided with connecting components when the movable roller and the fixed roller and the rolling wheel and the plate are lifted, so that the movable roller and the fixed roller are easy to shake when lifted, and the stability when lifted is difficult to ensure;

in the prior art, through control clamp plate and gyro wheel to panel one end surface roll pushing down, and not play limit function to the both ends of coiled plate, when the panel rolls up the circle on movable roller, can lead to the phenomenon that misplacement appears at the both ends of panel equally, and then influence follow-up welding process to current veneer reeling machine's performance has been reduced.

Disclosure of Invention

The utility model aims to provide an anti-rebound plate bending machine, which has the characteristics of stable lifting and strong anti-rebound performance, effectively solves the problems in the prior art and has the usability of the existing plate bending machine.

In order to achieve the above purpose, the present utility model provides the following technical solutions: the utility model provides an anti-rebound formula veneer reeling machine, includes the workstation, be provided with the support frame on the workstation perpendicularly, the middle part of workstation surface is provided with first elevating system, and first elevating system's top is connected with veneer reeling mechanism, transversely is provided with the roller subassembly that is used for placing the veneer reeling directly over the veneer reeling mechanism, is provided with the anti-rebound mechanism that is used for pressing the veneer reeling directly over the roller subassembly.

Preferably, the support frame includes support column, first spout, second spout and roof, and the support column has two, and symmetry and fixed the setting are at the both ends on workstation surface, are provided with two first spouts and second spouts on the inner wall of two support columns respectively symmetry, and wherein first spout is located under the second spout, the top and the roof fixed connection of two support columns.

Preferably, the first lifting mechanism comprises three electric push rods and buffer spring columns, wherein the three electric push rods are arranged at the bottom of the plate rolling mechanism in parallel, and two buffer spring columns are arranged between the three electric push rods in a staggered mode.

Preferably, the plate rolling mechanism comprises a transverse plate, a first connecting shaft, first balls, fixing frames, plate rolling roller shafts and a first motor, wherein two first connecting shafts are symmetrically arranged at two ends of the transverse plate, the first balls are arranged on the outer sides of the first connecting shafts and slidably inserted into the inner walls of two sides of the supporting frame, two fixing frames are symmetrically arranged on the surface of the transverse plate, three plate rolling roller shafts are arranged between the two fixing frames, two rotating assemblies are arranged at two ends of each of the three plate rolling roller shafts, and one end of each rotating assembly is connected with the first motor.

Preferably, the roll shaft assembly comprises a second motor, a rotating shaft, a bearing seat, a movable roll shaft and a limit ring, wherein the second motor is arranged on the outer side of the support frame, the output end of the second motor penetrates through the side edge of the support frame and extends to the inner side to be connected with the rotating shaft, the other end of the rotating shaft is connected with the bearing seat, the bearing seat is arranged on the inner wall of the other side of the support frame, the movable roll shaft is sleeved on the rotating shaft, and the limit ring is symmetrically sleeved at the two ends of the movable roll shaft.

Preferably, the rebound prevention mechanism comprises a cylinder, an air rod, an installation cavity, rebound prevention components, second connecting shafts and second balls, wherein the cylinder is provided with three second connecting shafts, the cylinder is arranged at the top of the supporting frame in parallel, the bottom of the cylinder is connected with the air rod, the bottom of the air rod penetrates through the top of the supporting frame and extends to the lower end to be connected with the installation cavity, the rebound prevention components are arranged in the installation cavity, the two second connecting shafts are symmetrically arranged at the two ends of the installation cavity, and the second balls are arranged at the outer sides of the second connecting shafts.

Preferably, the rebound prevention assembly comprises a double-shaft motor, a screw rod, a sliding block, clamping plates, clamping blocks, supporting shafts, connecting plates and rollers, wherein the double-shaft motor is arranged at the center of the inside of the installation cavity, the two ends of the double-shaft motor are respectively connected with the screw rods, the two screw rods are respectively sleeved with the sliding blocks, the bottoms of the two sliding blocks are vertically provided with the clamping plates, the clamping blocks are arranged on the inner sides of the clamping plates, the three supporting shafts are arranged in parallel at the center of the bottom of the installation cavity, the connecting plates are arranged at the bottoms of the supporting shafts, and the five rollers are arranged at the bottoms of the connecting plates in parallel.

Compared with the prior art, the utility model has the following beneficial effects:

1. according to the rebound-proof plate bending machine, the first sliding grooves and the second sliding grooves are respectively formed in the inner wall of the inner side of the supporting column, the first connecting shafts and the first balls are symmetrically arranged at the two ends of the transverse plate in the plate bending mechanism, the second connecting shafts and the second balls are symmetrically arranged at the two ends of the mounting cavity in the rebound-proof mechanism, the first balls at the two sides are respectively inserted into the first sliding grooves at the two ends, and the second balls are inserted into the second sliding grooves at the two ends, so that when the electric push rod in the first lifting mechanism pushes the transverse plate to move up and down, the first balls at the two ends can roll in the first sliding grooves, and the stability of the plate bending mechanism in lifting is improved; meanwhile, when the mounting cavity is driven to move up and down by the air cylinder in the rebound prevention mechanism, the mounting cavity and the rebound prevention component in the mounting cavity can roll in the second sliding groove by means of the second balls at the two ends, so that the stability of the mounting cavity and the rebound prevention component in the mounting cavity during lifting is improved; the shaking of the two plates during lifting is effectively avoided, so that the usability of the existing veneer reeling machine is improved.

2. According to the rebound-preventing plate bending machine, the air rod is driven to stretch and retract through the air cylinder in the rebound-preventing mechanism, so that the installation cavity and the rebound-preventing assembly inside the installation cavity are driven to lift until the rebound-preventing assembly moves downwards to the position right above the movable roll shaft; at the moment, the roller at the bottom of the roller is contacted with the surface of the coiled plate placed on the movable roller shaft, so that the surface of the coiled plate is pressed to prevent rebound; the double-shaft motor is started again to enable the screw rod to rotate, the sliding blocks at the two ends are driven to move in opposite directions, the clamping plates at the bottom of the double-shaft motor can be driven to move in opposite directions through the movement of the sliding blocks until the clamping blocks at the two ends are close to the two sides of the coiled plate, so that the two sides of the coiled plate are limited, dislocation at the two ends of the coiled plate is prevented, and the service performance of the existing plate bending machine is further improved.

Drawings

FIG. 1 is a schematic elevational view of the overall structure of the present utility model;

FIG. 2 is a schematic elevation view of a partial structure of the present utility model;

FIG. 3 is a schematic view of a plate bending mechanism connection of the present utility model;

FIG. 4 is a schematic front view of an anti-rebound mechanism of the present utility model;

FIG. 5 is a schematic front view of an anti-rebound assembly of the present utility model.

In the figure: 1. a work table; 2. a support frame; 3. a first lifting mechanism; 4. a plate rolling mechanism; 5. a roller assembly; 6. an anti-rebound mechanism; 21. a support column; 22. a first chute; 23. a second chute; 24. a top plate; 31. an electric push rod; 32. a buffer spring column; 41. a cross plate; 42. a first connecting shaft; 43. a first ball; 44. a fixing frame; 45. a roll rolling shaft; 46. a first motor; 51. a second motor; 52. a rotating shaft; 53. a bearing seat; 54. a movable roll shaft; 55. a limit ring; 61. a cylinder; 62. an air bar; 63. a mounting cavity; 64. an anti-rebound assembly; 641. a biaxial motor; 642. a screw rod; 643. a slide block; 644. a clamping plate; 645. clamping blocks; 646. a support shaft; 647. a connecting plate; 648. a roller; 65. a second connecting shaft; 66. and a second ball.

Description of the embodiments

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In order to solve the technical problem that the prior plate bending machine has reduced usability due to the fact that shaking is easy to occur in the lifting process and the two ends of the coiled plate are not limited simultaneously when the distance between the roller shafts is adjusted by the prior plate bending machine, refer to fig. 1-5, the embodiment provides the following technical scheme:

the utility model provides an anti-rebound veneer reeling machine, includes workstation 1, is provided with support frame 2 on the workstation 1 perpendicularly, and the middle part of workstation 1 surface is provided with first elevating system 3, and the top of first elevating system 3 is connected with veneer reeling mechanism 4, transversely is provided with the roller subassembly 5 that is used for placing the veneer reeling directly over the veneer reeling mechanism 4, is provided with the anti-rebound mechanism 6 that is used for the suppression veneer reeling directly over the roller subassembly 5.

Specifically, by movably inserting the two ends of the plate rolling mechanism 4 and the rebound preventing mechanism 6 into the inner walls on the two sides of the support frame 2 respectively, when the first lifting mechanism 3 pushes the plate rolling mechanism 4 to move up and down, the two ends of the first lifting mechanism can roll in the inner walls on the two sides of the support frame 2, so that the stability of the plate rolling mechanism 4 in lifting is improved; meanwhile, when the anti-rebound mechanism 6 moves up and down, the anti-rebound mechanism 6 can roll by means of the inner walls of the two sides of the supporting frames 2 at the two ends of the anti-rebound mechanism, so that the stability of the anti-rebound mechanism 6 during lifting is improved; the shaking of the two plates during lifting is effectively avoided, so that the usability of the existing veneer reeling machine is improved.

Secondly, placing the plate to be rolled in a rolling mechanism 4 for rolling, surrounding the plate subjected to preliminary rolling on a roll shaft assembly 5, starting an anti-rebound mechanism 6 to move downwards until the surfaces of the rolling plates placed on the roll shaft assembly 5 are contacted, and pressing the surfaces of the rolling plates to prevent rebound; the anti-rebound mechanism 6 plays a limiting function on two sides of the coiled plate, so that dislocation of two ends of the coiled plate is prevented, and the usability of the existing coiled plate machine is further improved.

The support frame 2 includes support column 21, first spout 22, second spout 23 and roof 24, and support column 21 has two, and the symmetry just sets up the both ends on workstation 1 surface, is provided with two first spouts 22 and second spout 23 on the inner wall of two support columns 21 respectively symmetry, and wherein first spout 22 is located the second spout 23 under, and the top and the roof 24 fixed connection of two support columns 21.

The inside of the first chute 22 is inserted into both ends of the plate rolling mechanism 4, the inside of the first chute 22 is inserted into both ends of the anti-rebound mechanism 6, and the first chute 22 and the second chute 23 are not communicated with each other; when the plate rolling mechanism 4 and the rebound prevention mechanism 6 are lifted, the two ends of the plate rolling mechanism can roll along the inner parts of the first chute 22 and the second chute 23 respectively, so that the stability of the plate rolling mechanism 4 and the rebound prevention mechanism 6 during lifting is improved.

The first lifting mechanism 3 comprises electric push rods 31 and buffer spring columns 32, wherein the electric push rods 31 are arranged at the bottom of the plate rolling mechanism 4 in parallel, and two buffer spring columns 32 are arranged between the three electric push rods 31 in a staggered mode.

It should be noted that, the electric push rod 31 is mainly used for providing lifting driving force for the plate rolling mechanism 4, the buffer spring column 32 is mainly used for providing buffering force for the plate rolling mechanism 4 when lifting, so that the pressure of the plate rolling mechanism 4 on the workbench 1 when lifting is weakened, and the practicability of the existing plate rolling machine is improved.

The plate rolling mechanism 4 comprises a transverse plate 41, a first connecting shaft 42, first balls 43, fixing frames 44, plate rolling roll shafts 45 and a first motor 46, wherein two first connecting shafts 42 are symmetrically arranged at two ends of the transverse plate 41, first balls 43 are arranged on the outer side of each first connecting shaft 42 and slidably inserted into inner walls of two sides of the supporting frame 2, two fixing frames 44 are symmetrically arranged on the surface of the transverse plate 41, three plate rolling roll shafts 45 are arranged between the two fixing frames 44, two rotating assemblies are arranged at two ends of each three plate rolling roll shafts 45, and one end of each rotating assembly is connected with the first motor 46.

Specifically, by placing the plate to be rolled between the three rolling plate roll shafts 45, the electric push rod 31 in the first lifting mechanism 3 is started to push the transverse plate 41 to move up and down, so as to adjust the distance between the rolling plate roll shaft 45 on the surface and the roll shaft assembly 5, two ends of the transverse plate 41 are respectively inserted into the first sliding grooves 22 on the inner wall of the support column 21 by means of the first connecting shaft 42 and the first balls 43, and when the transverse plate 41 is lifted, the transverse plate 41 can roll in the first sliding grooves 22 by means of the first balls 43 at two ends, so that the lifting stability of the rolling plate mechanism 4 is improved; each rotating assembly consists of a main gear, two auxiliary gears and a belt, wherein the interiors of the main gear and the two auxiliary gears are respectively sleeved with an installation shaft, the main gear and the two auxiliary gears are respectively connected with two ends of three rolling plate roll shafts 45 through the installation shafts, the two rolling plate roll shafts are sleeved outside the main gear and the two auxiliary gears through the belt, and one end of the main gear is connected with a first motor 46 to provide driving force for the rotating assembly; the first motor 46 is utilized to drive the main gear to drive the two auxiliary gears to rotate respectively, and then drive the three rolling plate roll shafts 45 to rotate, so that the plate clamped in the rolling plate rolls.

The roll shaft assembly 5 comprises a second motor 51, a rotating shaft 52, a bearing seat 53, a movable roll shaft 54 and a limit ring 55, wherein the second motor 51 is arranged on the outer side of the support frame 2, the output end of the second motor 51 penetrates through the side edge of the support frame 2 and extends to the inner side to be connected with the rotating shaft 52, the other end of the rotating shaft 52 is connected with the bearing seat 53, the bearing seat 53 is arranged on the inner wall of the other side of the support frame 2, the movable roll shaft 54 is sleeved on the rotating shaft 52, and the limit rings 55 are symmetrically sleeved at two ends of the movable roll shaft 54.

Specifically, by starting the electric push rod 31 in the first lifting mechanism 3 to push the transverse plate 41 to move up and down, the distance between the plate rolling roll shafts 45 and the movable roll shafts 54 on the surfaces of the transverse plate is adjusted, and the first motor 46 is utilized to drive the rotating assembly to drive the three plate rolling roll shafts 45 to rotate, so that the plate clamped in the plate rolling roll shafts are coiled; the plate after preliminary rolling passes through the upper part of the roll shaft assembly 5 and surrounds the movable roll shaft 54 so that the upper rebound prevention mechanism 6 presses the coiled plate.

The anti-rebound mechanism 6 comprises an air cylinder 61, an air rod 62, a mounting cavity 63, an anti-rebound component 64, a second connecting shaft 65 and second balls 66, wherein the air cylinder 61 is arranged at the top of the support frame 2 in parallel, the bottom of the air cylinder 61 is connected with the air rod 62, the bottom end of the air rod 62 penetrates through the top of the support frame 2 and extends to the lower end to be connected with the mounting cavity 63, the anti-rebound component 64 is arranged in the mounting cavity 63, two second connecting shafts 65 are symmetrically arranged at two ends of the mounting cavity 63, and the second balls 66 are arranged on the outer side of the second connecting shaft 65.

The rebound prevention assembly 64 comprises a double-shaft motor 641, a screw rod 642, sliding blocks 643, clamping plates 644, clamping blocks 645, supporting shafts 646, connecting plates 647 and rollers 648, wherein the double-shaft motor 641 is arranged at the center of the inside of the installation cavity 63, the two ends of the double-shaft motor 641 are respectively connected with the screw rod 642, the sliding blocks 643 are respectively sleeved on the two screw rods 642, the clamping plates 644 are vertically arranged at the bottoms of the two sliding blocks 643, the clamping blocks 645 are arranged at the inner sides of the clamping plates 644, three supporting shafts 646 are arranged at the center of the bottoms of the installation cavity 63 in parallel, the connecting plates 647 are arranged at the bottoms of the supporting shafts 646 in parallel, and five rollers 648 are arranged at the bottoms of the connecting plates 647 in parallel.

Specifically, the air rod 62 is driven to stretch and retract by the air cylinder 61, so that the installation cavity 63 and the rebound prevention assembly 64 inside the installation cavity are driven to lift until the rebound prevention assembly 64 moves down to the position right above the movable roll shaft 54; at this time, the roller 648 at the bottom thereof is in contact with the surface of the rolled sheet placed on the movable roller shaft 54, thereby pressing the surface of the rolled sheet against rebound; the double-shaft motor 641 is started again to enable the screw rod 642 to rotate, and then the sliding blocks 643 at two ends are driven to move in opposite directions, and the clamping plates 644 and the clamping blocks 645 at the bottom of the double-shaft motor 643 can be driven to move in opposite directions through the movement of the sliding blocks 643 until the clamping blocks 645 at two ends are close to two sides of a coiled plate, so that the two sides of the coiled plate are limited, dislocation at two ends of the coiled plate is prevented, and the service performance of the existing plate bending machine is further improved.

Working principle: the first sliding groove 22 and the second sliding groove 23 are formed in the inner wall of the supporting column 21, the first connecting shaft 42 and the first rolling ball 43 are symmetrically arranged at two ends of the transverse plate 41, the second connecting shaft 65 and the second rolling ball 66 are symmetrically arranged at two ends of the mounting cavity 63, the first rolling ball 43 is inserted into the first sliding groove 22, the second rolling ball 66 is inserted into the second sliding groove 23, so that the electric push rod 31 can roll in the first sliding groove 22 by the aid of the first rolling ball 43 when pushing the transverse plate 41 to lift, and the air cylinder 61 can roll in the second sliding groove 23 by the aid of the second rolling ball 66 when driving the mounting cavity 63 to lift, so that shaking is avoided during lifting; the mounting cavity 63 is driven to lift by the air cylinder 61 until the roller 648 contacts the surface of the coiled plate to press and prevent rebound; starting the double-shaft motor 641 causes the two-end sliding blocks 643 to drive the clamping blocks 645 to move in opposite directions until the clamping blocks 645 are close to two sides of the coiled plate to limit, dislocation at two ends of the coiled plate is prevented, and the usability of the existing coiled plate machine is improved.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims (5)

1. The utility model provides an anti-rebound formula veneer reeling machine, includes workstation (1), its characterized in that: the automatic rolling machine is characterized in that a supporting frame (2) is vertically arranged on the workbench (1), a first lifting mechanism (3) is arranged in the middle of the surface of the workbench (1), the upper part of the first lifting mechanism (3) is connected with a rolling plate mechanism (4), a roll shaft assembly (5) for placing a rolling plate is transversely arranged right above the rolling plate mechanism (4), an anti-rebound mechanism (6) for pressing the rolling plate is arranged right above the roll shaft assembly (5), the anti-rebound mechanism (6) comprises a cylinder (61), an air rod (62), a mounting cavity (63), an anti-rebound assembly (64), a second connecting shaft (65) and a second ball (66), the cylinder (61) is provided with three parts, the three parts are arranged in parallel at the top of the supporting frame (2), the bottom of the cylinder (61) is connected with an air rod (62), the bottom end of the air rod (62) penetrates through the top of the supporting frame (2) and extends to the lower end to be connected with the mounting cavity (63), anti-rebound assemblies (64) are arranged in the mounting cavity (63), two ends of the mounting cavity (63) are symmetrically provided with two second connecting shafts (65), two outer side clamping blocks (641), two clamping blocks (643) are arranged, each of which comprise a sliding block (643), and a sliding block (643) which comprises two clamping blocks (643) Back shaft (646), connecting plate (647) and gyro wheel (648), biax motor (641) set up in the inside center department of installation cavity (63), the both ends of biax motor (641) are connected with lead screw (642) respectively, slider (643) have been cup jointed respectively on two lead screws (642), the bottom of two slider (643) is provided with splint (644) perpendicularly, the inboard of splint (644) is provided with clamp splice (645), the center department parallel arrangement of installation cavity (63) bottom has three back shaft (646), the bottom of back shaft (646) is provided with connecting plate (647), the bottom parallel arrangement of connecting plate (647) has five gyro wheels (648).

2. The anti-rebound rolling machine as claimed in claim 1, wherein: support frame (2) are including support column (21), first spout (22), second spout (23) and roof (24), and support column (21) have two, and symmetry and fixed the setting are at the both ends on workstation (1) surface, are provided with two first spouts (22) and second spout (23) on the inner wall of two support columns (21) respectively symmetry, and wherein first spout (22) are located under second spout (23), the top and roof (24) fixed connection of two support columns (21).

3. The anti-rebound rolling machine as claimed in claim 1, wherein: the first lifting mechanism (3) comprises three electric push rods (31) and buffer spring columns (32), wherein the electric push rods (31) are arranged at the bottom of the plate rolling mechanism (4) in parallel, and two buffer spring columns (32) are arranged between the three electric push rods (31) in a staggered mode.

4. The anti-rebound rolling machine as claimed in claim 1, wherein: the plate rolling mechanism (4) comprises a transverse plate (41), a first connecting shaft (42), first balls (43), fixing frames (44), plate rolling roll shafts (45) and a first motor (46), wherein two first connecting shafts (42) are symmetrically arranged at two ends of the transverse plate (41), the first balls (43) are arranged on the outer sides of the first connecting shafts (42), the first balls (43) are slidably inserted into the inner walls of two sides of the supporting frame (2), two fixing frames (44) are symmetrically arranged on the surface of the transverse plate (41), three plate rolling roll shafts (45) are arranged between the two fixing frames (44), two rotating assemblies are arranged at two ends of each of the three plate rolling roll shafts (45), and one end of each rotating assembly is connected with the corresponding first motor (46).

5. The anti-rebound rolling machine as claimed in claim 1, wherein: the roller assembly (5) comprises a second motor (51), a rotating shaft (52), a bearing seat (53), a movable roller shaft (54) and a limit ring (55), wherein the second motor (51) is arranged on the outer side of the support frame (2), the output end of the second motor (51) penetrates through the side edge of the support frame (2) and extends to the inner side to be connected with the rotating shaft (52), the other end of the rotating shaft (52) is connected with the bearing seat (53), the bearing seat (53) is arranged on the inner wall of the other side of the support frame (2), the movable roller shaft (54) is sleeved on the rotating shaft (52), and the limit ring (55) is symmetrically sleeved at two ends of the movable roller shaft (54).