WO2024088126A1

WO2024088126A1 - Guide rotating mechanism for sliding plate

Info

Publication number: WO2024088126A1
Application number: PCT/CN2023/125173
Authority: WO
Inventors: 钱文涛; 缪萃峰
Original assignee: 天奇自动化工程股份有限公司
Priority date: 2022-10-25
Filing date: 2023-10-18
Publication date: 2024-05-02
Also published as: CN116119298A

Abstract

The present invention relates to a guide rotating mechanism for a sliding plate, comprising a fixed frame. A supporting frame is arranged at one end of the fixed frame. A turnover support is mounted on an upper portion of the supporting frame, and an air cylinder is mounted at an upper portion of the other end of the fixed frame. A cylinder body of the air cylinder is hinged to an upper surface of the fixed frame. A push seat is mounted in the middle of the fixed frame in a sliding fit manner. An output end of the air cylinder is connected to the push seat, and a movement direction of the output end of the air cylinder is a horizontal linear direction. One end of the turnover support is hinged to the supporting frame, and a guide wheel assembly matched with a side edge of the sliding plate is mounted on an upper side of the other end of the turnover support. The turnover support below the guide wheel assembly is in sliding fit with an upper surface of the push seat. When the push seat slides under the driving of the air cylinder, the turnover support is driven to turn over upwards so that the guide wheel assembly matches with the side edge of the sliding plate. Therefore, the swing amplitude of a guide structure is reduced, while the guiding action of the rotating mechanism during use is stable, and a matching structure of the guide structure and the sliding plate is precise and controllable.

Description

A slide plate guide rotation mechanism

Technical Field

The invention relates to the technical field of guide devices, in particular to a slide plate guide rotation mechanism.

Background technique

In modern industry, the requirements for automation of conveyor lines are getting higher and higher, and the requirements for the stability of conveyor lines and the human-machine environment are also getting higher and higher. For conveyor lines in large workpiece assembly workshops, such as the interior lines of automobile assembly workshops, there are usually many conveying methods, such as skateboard type, suspension type, etc., to achieve assembly work. The skateboard conveyor line using friction drive as the power is an important form of interior conveyor line in automobile assembly workshops. Because the equipment requirements are relatively simple, the changes are relatively flexible, and the adaptability is relatively good in actual production life, it has been widely used.

technical problem

The friction-driven skateboard conveyor line is usually in the form of a ground non-powered roller line. The friction drive provides power to drive the skateboard to run on the non-powered roller, and the skateboard needs to change direction in the vertical direction at the end of the line. At the turning point of the line, the friction drive is used in conjunction with the right-angle lifting device to achieve transportation in two directions perpendicular to each other. At the same time, multiple skateboard guide structures are set to guide in two directions to prevent the skateboard from deviating and not hinder the passage of the skateboard. After the skateboard enters the right-angle lifting device and moves in the vertical direction, the guide structure in the original movement direction needs to change its posture to be lower than the skateboard plane to prevent collision with the skateboard. At present, the drive structure is usually used to directly rotate the guide structure 90 degrees to achieve the change of the guide structure's posture and cooperate with the side of the skateboard. The swing amplitude of the guide structure of this mechanism is large, and the stability of the mechanism is poor while occupying a large space. The coordination structure of the guide structure and the skateboard is not stable and accurate enough.

Technical Solutions

In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a slide plate guide rotation mechanism, thereby reducing the swing amplitude of the guide structure, while making the guiding action of the rotation mechanism smooth during use, and the matching structure between the guide structure and the slide plate is precisely controllable.

The technical solution adopted by the present invention is as follows:

A skateboard guiding and rotating mechanism comprises a fixed frame, a supporting frame is arranged at one end of the fixed frame, a flipping bracket is installed on the upper part of the supporting frame, a cylinder is installed on the upper part of the other end of the fixed frame, the cylinder body is hinged to the upper surface of the fixed frame, a pushing seat is installed in the middle part of the fixed frame in a sliding manner, the output end of the cylinder is connected to the pushing seat, the movement direction of the output end of the cylinder is a horizontal straight line direction, one end of the flipping bracket is hinged to the supporting frame, a guide wheel assembly that cooperates with the side of the skateboard is installed on the upper side of the other end of the flipping bracket, the flipping bracket below the guide wheel assembly is slidably cooperated with the upper surface of the pushing seat, and when the pushing seat slides under the drive of the cylinder, it drives the flipping bracket to flip upward so that the guide wheel assembly cooperates with the side of the skateboard.

As a further improvement of the above technical solution:

The structure of the flip bracket assembly is as follows: it includes a horizontally arranged rotating shaft, the rotating shaft is connected to the support frame, two connecting plates are arranged in parallel and spaced apart in the middle of the rotating shaft, one end of the connecting plate is fixedly connected to the rotating shaft, a sliding wheel is arranged between the other ends of the two connecting plates, the sliding wheel cooperates with the connecting plates, and also includes a mounting plate for installing the guide wheel assembly, the bottom of the mounting plate is connected to the sides of the two connecting plates at the same time, and the sliding wheel is slidably matched with the upper surface of the pushing seat.

The upper surface of the mounting plate is provided with a fixing block with a hole in the middle, and the fixing block is connected to the guide wheel assembly.

A limiting piece is arranged on the rotating shaft, and an end of the limiting piece is matched with the upper part of the supporting frame.

The structure of the pushing seat is as follows: it includes two vertically arranged support plates, the bottoms of the two support plates are slidably connected to the fixed frame, and sliding plates are installed on the upper ends of the two support plates. The length direction of the sliding plates corresponds to the movement direction of the output end of the cylinder. The middle part of the sliding plate along the length direction is a lifting part, and a lower transition part is arranged at one end of the lifting part along the length direction. An upper transition part is arranged at one end of the lifting part along the length direction. The upper surface of the lifting part is an inclined plane, and the upper surface of the upper transition part is higher than the upper surface of the lower transition part. The upper surfaces of the lifting part, the lower transition part and the upper transition part are all slidably matched with the flip bracket assembly, and the support plate on one side of the upper transition part is connected to the output end of the cylinder.

The angle between the upper surface of the lifting part and the horizontal plane is 25°-35°.

The upper surface of the upper transition part is a plane parallel to the horizontal plane, and the upper surface of the upper transition part and the upper surface of the lifting part are smoothly transitioned. The upper surface of the lower transition part is a plane parallel to the horizontal plane, and the upper surface of the lower transition part and the upper surface of the lifting part are smoothly transitioned.

The structure of the guide wheel assembly is as follows: it comprises a central shaft mounted on the flip bracket, the outer periphery of the central shaft is rotatably connected with a guide wheel body, and the outer circumferential surface of the guide wheel body is slidably matched with the side of the skateboard.

One end of the central shaft is mounted on the flip bracket through a support seat, and a screw rod perpendicular to the axis of the central shaft is arranged on one side of the support seat, and the screw rod cooperates with the flip bracket.

The structure of the support frame is as follows: it includes symmetrically arranged columns, a connecting seat plate is arranged on the upper part of the columns, the lower surface of the connecting seat plate is connected to the upper surface of the columns at the same time, the upper surface of the connecting seat plate is symmetrically provided with a bearing seat hinged to the flip bracket, and the upper surface of the connecting seat plate cooperates with the flip bracket.

Beneficial Effects

The beneficial effects of the present invention are as follows:

The present invention has a simple, compact and reasonable structure. It adopts a pushing seat to horizontally push the flip bracket to flip, thereby realizing a smooth flipping of the guide wheel assembly. At the same time, the hinged part of the flip bracket is raised while ensuring the overall height of the rotating mechanism, thereby reducing the space occupied by the swing of the guide wheel assembly, thereby reducing the floor area of the steering skateboard line.

The present invention also includes the following advantages:

(1) By setting a sliding plate with a plane, an inclined plane, and a plane that smoothly transition in sequence, the sliding plate and the sliding wheel can slide together to make the entire flipping action smooth and achieve a smooth transition at the beginning and end of the flipping action.

(2) The end of the limiter cooperates with the upper surface of the connecting seat plate on the upper part of the support frame to serve as a limit for the flip bracket assembly, thereby ensuring that the flip bracket assembly does not exceed the maximum flip angle when flipping, and ensuring safe transportation of the slide in the event of a failure in the drive structure of the conveyor line.

(3) The screw on the guide wheel assembly support seat cooperates with the fixed block of the flip bracket assembly to facilitate the adjustment of the degree of cooperation between the guide wheel assembly and the side of the skateboard after flipping, thereby ensuring the guiding accuracy and smooth guiding process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three-dimensional view of the present invention (after the flip bracket is flipped upward).

FIG. 2 is an exploded view of the present invention.

FIG. 3 is an exploded view of the present invention (from another perspective).

FIG. 4 is a schematic diagram of the structure of the present invention (after the flip bracket is flipped upward).

FIG. 5 is a schematic diagram of the structure of the present invention (before the flip bracket is flipped upward).

FIG. 6 is a schematic structural diagram of the flip bracket of the present invention.

FIG. 7 is a schematic structural diagram of the flip bracket of the present invention (from another viewing angle).

FIG. 8 is a bottom view of the flip bracket of the present invention.

FIG9 is a cross-sectional view of section A-A in FIG8.

FIG. 10 is a schematic structural diagram of the push seat of the present invention.

FIG. 11 is a front view of the push seat of the present invention.

FIG. 12 is a schematic structural diagram of the guide wheel assembly of the present invention.

FIG. 13 is a cross-sectional view of the guide wheel assembly of the present invention.

FIG. 14 is an installation layout diagram of the slide conveyor line of the present invention.

FIG. 15 is a partial enlarged view of point B in FIG. 14 .

Among them: 1. Side of the skateboard; 2. Guide wheel assembly; 3. Flip bracket; 4. Push seat; 5. Fixed frame; 6. Cylinder;

21. Central axis; 22. Guide wheel body; 23. Support seat; 24. Screw;

31. Rotating shaft; 32. Connecting plate; 33. Sliding wheel; 34. Mounting plate; 35. Fixing block; 36. Limiting member;

3301, mounting shaft; 3302, pulley body; 3303, flanged copper sleeve; 3304, spacer sleeve;

40. Sliding plate; 41. Lifting portion; 42. Lower transition portion; 43. Upper transition portion; 44. Support plate;

51, support frame; 5101, column; 5102, connecting seat plate; 5103, bearing seat;

a. Slide plate guide rotation mechanism; b. Friction drive mechanism; c. Slide plate.

Embodiments of the present invention

The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

As shown in Figures 1 to 5, the skateboard guiding and rotating mechanism of this embodiment includes a fixed frame 5, a support frame 51 is set at one end of the fixed frame 5, a flip bracket 3 is installed on the upper part of the support frame 51, a cylinder 6 is installed on the upper part of the other end of the fixed frame 5, the cylinder body of the cylinder 6 is hinged to the upper surface of the fixed frame 5, a pushing seat 4 is slidably installed in the middle part of the fixed frame 5, the output end of the cylinder 6 is connected to the pushing seat 4, and the movement direction of the output end of the cylinder 6 is a horizontal straight line direction. One end of the flip bracket 3 is hinged to the support frame 51, and a guide wheel assembly 2 that cooperates with the side edge 1 of the skateboard is installed on the upper side of the other end of the flip bracket 3. The flip bracket 3 below the guide wheel assembly 2 is slidably matched with the upper surface of the pushing seat 4. When the pushing seat 4 slides under the drive of the cylinder 6, it drives the flip bracket 3 to flip upward so that the guide wheel assembly 2 cooperates with the side edge 1 of the skateboard.

The cylinder 6 and the flip bracket 3 are slidably matched to drive the push seat 4, which converts the horizontal linear motion of the output end of the cylinder 6 into the rotation of the flip bracket 3 around the hinged part. This flipping structure is stable, and the flip bracket 3 is supported by the push seat 4 during the rotation process, so that the flip bracket 3 can move smoothly. The support frame 51 is set to lift the flip bracket 3 after flipping it around the hinged part, so that the horizontal and vertical space occupied by the swing amplitude of the guide wheel assembly 2 is greatly reduced, the distance between two adjacent slides is shortened, and the overall footprint of the line body is reduced. The cylinder 6, the push seat 4, and the flip bracket 3 are arranged on the fixed frame 5, so that the rotating mechanism structure is flat and suitable for installation under the slide conveyor line.

The push seat 4 is used to horizontally push the flip bracket 3 to flip, thereby achieving a smooth flipping of the guide wheel assembly 2. At the same time, the hinge part of the flip bracket 3 is raised while ensuring the overall height of the rotating mechanism, thereby reducing the space occupied by the swing of the guide wheel assembly 2, thereby reducing the floor area of the steering skateboard line.

The push seat 4 is slidably mounted on the fixed frame 5 through a slide rail and slider structure.

As shown in Figures 12 and 13, the structure of the guide wheel assembly 2 is: it includes a central shaft 21 installed on the flip bracket 3, the outer periphery of the central shaft 21 is rotatably connected to a guide wheel body 22, and the outer circumferential surface of the guide wheel body 22 is slidably matched with the side edge 1 of the skateboard.

One end of the central shaft 21 is mounted on the flip bracket 3 through a support seat 23 . A screw rod 24 perpendicular to the axis of the central shaft 21 is disposed on one side of the support seat 23 . The screw rod 24 cooperates with the flip bracket 3 .

As shown in Figures 6 to 9, the structure of the flip bracket assembly 3 is as follows: it includes a horizontally arranged rotating shaft 31, the rotating shaft 31 is connected to the support frame 51, two connecting plates 32 are arranged in parallel and spaced apart in the middle of the rotating shaft 31, one end of the connecting plate 32 is fixedly connected to the rotating shaft 31, and a sliding wheel 33 is arranged between the other ends of the two connecting plates 32, the sliding wheel 33 cooperates with the connecting plate 32, and also includes a mounting plate 34 for installing the guide wheel assembly 2, the bottom of the mounting plate 34 is connected to the sides of the two connecting plates 32 at the same time, and the sliding wheel 33 is slidably matched with the upper surface of the pushing seat 4.

The structure of the sliding wheel 33 is as follows, including a mounting shaft 3301, both ends of which are respectively connected to two connecting plates 32, a pulley body 3302 is mounted on the middle part of the mounting shaft 3301 between the two connecting plates 32, and flanged copper sleeves 3303 are mounted on the mounting shaft 3301 at both ends of the pulley body 3302, the flanged copper sleeves 3303 are matched with the ends of the pulley body 3302 at the same time, a spacer sleeve 3304 is also arranged between the flanged copper sleeve 3303 and the connecting plate 32, and the circumferential surface of the pulley body 3302 is slidably matched with the upper surface of the pushing seat 4.

A fixing block 35 with a hole in the middle is provided on the upper surface of the mounting plate 34, and the fixing block 35 is connected to the guide wheel assembly 2. After the screw 24 passes through the hole in the middle of the fixing block 35, the position of the upper support seat 23 of the guide wheel assembly 2 on the mounting plate 34 is locked by adjusting the relative position of the fixing block 35 and the screw 24. The screw 24 on the support seat 23 of the guide wheel assembly 2 cooperates with the fixing block 35 of the flip bracket assembly 3, so as to facilitate the adjustment of the degree of cooperation between the guide wheel assembly 2 after flipping and the side edge 1 of the skateboard, thereby ensuring the guiding accuracy and smooth guiding process.

A limiting member 36 is disposed on the rotating shaft 31 , and an end of the limiting member 36 is matched with an upper portion of the supporting frame 51 .

As shown in Fig. 10-Fig. 11, the structure of the push seat 4 is as follows: it includes two vertically arranged support plates 44, the bottom of the two support plates 44 is slidably connected with the fixed frame 5, the upper end of the two support plates 44 is installed with a sliding plate 40, the length direction of the sliding plate 40 corresponds to the movement direction of the output end of the cylinder 6, the middle part of the sliding plate 40 along the length direction is a lifting part 41, the lifting part 41 is provided with a lower transition part 42 at one end along the length direction, and the lifting part 41 is provided with an upper transition part 43 at one end along the length direction. The upper surface of the lifting part 41 is an inclined plane, the upper surface of the upper transition part 43 is higher than the upper surface of the lower transition part 42, the upper surface of the lifting part 41, the upper surface of the lower transition part 42 and the upper surface of the upper transition part 43 are all slidably matched with the flip bracket assembly 3, and the support plate 44 on one side of the upper transition part 43 is connected to the output end of the cylinder 6. The sliding wheel 33 slides on the surface of the sliding plate 40, and the flipping of the flip bracket assembly 3 is achieved by changing the position of the sliding wheel 33 on the sliding plate 40.

The angle between the upper surface of the lifting portion 41 and the horizontal plane is 25°-35°.

The upper surface of the upper transition portion 43 is a plane parallel to the horizontal plane, and the upper surface of the upper transition portion 43 smoothly transitions to the upper surface of the lifting portion 41 . The upper surface of the lower transition portion 42 is a plane parallel to the horizontal plane, and the upper surface of the lower transition portion 42 smoothly transitions to the upper surface of the lifting portion 41 .

By providing a sliding plate 40 with a plane, an inclined surface, and a plane that smoothly transition in sequence, the sliding plate 40 and the sliding wheel 33 can slide together to make the entire flipping action smooth and achieve a smooth transition at the beginning and end of the flipping action.

As shown in Fig. 1 to Fig. 5, a support frame 51 hinged to the flip bracket 3 is provided at one end of the fixed frame 5, and the structure of the support frame 51 is as follows: it includes symmetrically arranged columns 5101, a connecting seat plate 5102 is provided on the upper part of the columns 5101, the lower surface of the connecting seat plate 5102 is simultaneously connected to the upper surface of the column 5101, and a bearing seat 5103 hinged to the flip bracket 3 is symmetrically provided on the upper surface of the connecting seat plate 5102, and the upper surface of the connecting seat plate 5102 cooperates with the flip bracket 3. The rotating shaft 31 of the flip bracket assembly 3 is installed in cooperation with the bearing seat 5103.

The end of the limiter 36 cooperates with the upper surface of the connecting seat plate 5102 on the upper part of the support frame 51 to serve as a limit for the flip bracket assembly 3, ensuring that the flip bracket assembly 3 does not exceed the maximum flip angle when flipping, and ensuring the safe transportation of the slide in the event of a failure in the driving structure of the conveyor line.

The slide plate guide rotation mechanism of this embodiment, in actual working process:

As shown in Figures 4 and 5, the output end of the cylinder 6 moves forward, driving the push seat 4 to slide forward on the fixed frame 5, and the sliding wheel 33 slides on the surface of the sliding plate 40 of the push seat 4 and lifts upward to drive the flip bracket assembly 3 to rotate around the bearing seat 5103 as a whole. After the flip bracket assembly 3 flips upward into place, the guide wheel assembly 2 is in the state of guiding the side 1 of the slide plate; conversely, the output end of the cylinder 6 moves in the opposite direction, driving the guide wheel assembly 2 to flip downward and then be in a low position.

As shown in Figures 14 and 15, when located at the turning point of the conveyor line, a group of skateboard guide rotating mechanisms a are respectively arranged in the two perpendicular conveyor line directions. There are multiple skateboard guide rotating mechanisms a in each group. The skateboard guide rotating mechanisms a in each group are arranged side by side along the conveying direction of the skateboard c corresponding to it, and the skateboard c is driven forward by the friction drive mechanism b arranged on the side of the skateboard c.

When the skateboard c needs to run in the Y direction, a set of guide wheel assemblies 2 of the skateboard guide rotating mechanism a arranged perpendicular to the X direction are flipped up and lifted to cooperate with the side edge 1 of the skateboard to play a guiding role in the Y direction; at the same time, a set of guide wheel assemblies 2 of the skateboard guide rotating mechanism a arranged perpendicular to the X direction are flipped down and their posture is lower than the plane of the skateboard to prevent the guide wheel assemblies 2 from colliding with the skateboard c.

The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

A skateboard guide rotation mechanism comprises a fixed frame (5), characterized in that: a support frame (51) is provided at one end of the fixed frame (5), a flip bracket (3) is installed on the upper part of the support frame (51), a cylinder (6) is installed on the upper part of the other end of the fixed frame (5), the cylinder body of the cylinder (6) is hinged to the upper surface of the fixed frame (5), a push seat (4) is slidably mounted in the middle of the fixed frame (5), the output end of the cylinder (6) is connected to the push seat (4), the output end of the cylinder (6) moves in a horizontal straight line direction, one end of the flip bracket (3) is hinged to the support frame (51), a guide wheel assembly (2) that matches the side edge (1) of the skateboard is installed on the upper side of the other end of the flip bracket (3), the flip bracket (3) below the guide wheel assembly (2) is slidably matched with the upper surface of the push seat (4), and when the push seat (4) slides under the drive of the cylinder (6), it drives the flip bracket (3) to flip upward so that the guide wheel assembly (2) matches the side edge (1) of the skateboard.
A skateboard guide rotation mechanism as described in claim 1, characterized in that: the structure of the flip bracket assembly (3) is as follows: it includes a horizontally arranged rotation shaft (31), the rotation shaft (31) is connected to the support frame (51), two connecting plates (32) are arranged in parallel and spaced apart in the middle of the rotation shaft (31), one end of the connecting plate (32) is fixedly connected to the rotation shaft (31), a sliding wheel (33) is arranged between the other ends of the two connecting plates (32), the sliding wheel (33) cooperates with the connecting plate (32), and also includes a mounting plate (34) for mounting the guide wheel assembly (2), the bottom of the mounting plate (34) is simultaneously connected to the side edges of the two connecting plates (32), and the sliding wheel (33) is slidably matched with the upper surface of the pushing seat (4).
A skateboard guide rotation mechanism as claimed in claim 2, characterized in that: a fixing block (35) with a hole in the middle is provided on the upper surface of the mounting plate (34), and the fixing block (35) is connected to the guide wheel assembly (2).
A skateboard guide rotation mechanism according to claim 2, characterized in that: a limiting member (36) is provided on the rotation shaft (31), and an end of the limiting member (36) cooperates with an upper portion of the support frame (51).
A slide guide rotation mechanism as claimed in claim 1, characterized in that: the structure of the pushing seat (4) is as follows: it includes two vertically arranged support plates (44), the bottoms of the two support plates (44) are slidably connected to the fixed frame (5), the upper ends of the two support plates (44) are equipped with sliding plates (40), the length direction of the sliding plates (40) corresponds to the movement direction of the output end of the cylinder (6), the middle part of the sliding plate (40) along the length direction is a lifting part (41), one end of the lifting part (41) along the length direction is provided with a lower transition part (42), one end of the lifting part (41) along the length direction is provided with an upper transition part (43), the upper surface of the lifting part (41) is an inclined plane, the upper surface of the upper transition part (43) is higher than the upper surface of the lower transition part (42), the upper surfaces of the lifting part (41), the lower transition part (42) and the upper transition part (43) are all slidably matched with the flip bracket assembly (3), and the support plate (44) on one side of the upper transition part (43) is connected to the output end of the cylinder (6).
The slide plate guide rotation mechanism according to claim 5 is characterized in that the angle between the upper surface of the lifting part (41) and the horizontal plane is 25°-35°.
A slide guide rotation mechanism as described in claim 5, characterized in that: the upper surface of the upper transition portion (43) is a plane parallel to the horizontal plane, and the upper surface of the upper transition portion (43) and the upper surface of the lifting portion (41) are smoothly transitioned, and the upper surface of the lower transition portion (42) is a plane parallel to the horizontal plane, and the upper surface of the lower transition portion (42) and the upper surface of the lifting portion (41) are smoothly transitioned.
A skateboard guide rotation mechanism as claimed in claim 1, characterized in that: the structure of the guide wheel assembly (2) is as follows: it includes a central shaft (21) installed on the flip bracket (3), the outer periphery of the central shaft (21) is rotatably connected to a guide wheel body (22), and the outer circumferential surface of the guide wheel body (22) is slidably matched with the side edge (1) of the skateboard.
A skateboard guide rotation mechanism as claimed in claim 8, characterized in that one end of the central axis (21) is mounted on the flip bracket (3) through a support seat (23), and a screw rod (24) perpendicular to the axis of the central axis (21) is provided on one side of the support seat (23), and the screw rod (24) cooperates with the flip bracket (3).
A skateboard guide rotation mechanism as described in claim 1, characterized in that: the structure of the support frame (51) is: including symmetrically arranged columns (5101), a connecting seat plate (5102) is arranged on the upper part of the columns (5101), the lower surface of the connecting seat plate (5102) is simultaneously connected to the upper surface of the columns (5101), the upper surface of the connecting seat plate (5102) is symmetrically provided with a bearing seat (5103) hinged to the flip bracket (3), and the upper surface of the connecting seat plate (5102) cooperates with the flip bracket (3).