Top drive well drilling device

Abstract

The invention relates to the technical field of top drive well drilling, and provides a top drive well drilling device which comprises a supporting frame arranged on a working face, at least two centralizing blocks arranged in the supporting frame and a sliding device used for driving the centralizing blocks to descend together with a rotating shaft. The rotating shaft is in a vertical state under the combined action of the multiple centralizing blocks, each centralizing block is provided with an arc-shaped groove, the arc-shaped grooves abut against the outer wall of the rotating shaft, and the centralizing blocks are fixedly connected with the sliding device. The centering device has the beneficial effects that the centering block is used for centering the rotating shaft to ensure that the rotating shaft is in a vertical state, and in the rotating and gliding process of the rotating shaft, the sliding device is used for driving the centering block and the rotating shaft to synchronously descend, so that the centering block and the rotating shaft are in a relatively static position in the vertical direction; abrasion of the centralizing block to the rotating shaft when the rotating shaft slides down is avoided, the probability that the rotating shaft deflects in the drilling process is reduced, and the purpose of improving the drilling working efficiency is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of top drive drilling, and more specifically, to a top drive drilling apparatus. Background Technology

[0002] Currently, in the fields of oil, natural gas, and mineral resource exploration and development, drilling engineering is a core pre-existing step in resource extraction. Its operational efficiency, safety, and adaptability directly determine the economic viability and feasibility of resource development. Top drive drilling rigs, as core equipment in modern drilling engineering, have been widely used in scenarios such as onshore deep or ultra-deep well drilling, offshore platform drilling, shale gas horizontal well drilling, and polar drilling.

[0003] In oilfield drilling, the top-drive rotary shaft is a crucial piece of equipment. It primarily drives the drill string to rotate, thus enabling drilling operations. Connected to the drill string, the top-drive rotary shaft rotates at a specific speed and torque, helping the drill bit break rocks and achieve the drilling objective. However, during oilfield drilling, the rotary shaft sometimes becomes misaligned due to lateral vibrations generated during drilling, requiring readjustment of the rotary shaft and drill string to a vertical position. This results in low drilling efficiency, necessitating a new technical solution to address these issues. Summary of the Invention

[0004] This application proposes a top-drive drilling device that uses a centering block to straighten the rotating shaft, ensuring that the rotating shaft is in a vertical state, reducing the probability of adjusting the rotating shaft and drill pipe, and improving drilling efficiency.

[0005] Therefore, this application provides a top-drive drilling device, including a support frame disposed on the working face, a centralizing block disposed within the support frame, and a sliding device for driving the centralizing block to descend together with the rotating shaft. At least two centralizing blocks are provided, and the combined action of several centralizing blocks keeps the rotating shaft in a vertical state. Each centralizing block is provided with an arc-shaped groove, which abuts against the outer wall of the rotating shaft. The centralizing block is fixedly connected to the sliding device.

[0006] By adopting the above technical solution: when performing top drive drilling, the drive shaft is first moved into the support frame, so that the rotating shaft abuts against the centralizing blocks. The rotating shaft is held vertically by several centralizing blocks. At the same time, the arc grooves on the centralizing blocks increase the contact area with the rotating shaft, increasing the stability of the centralizing blocks when centralizing the rotating shaft. During the rotation and downward movement of the rotating shaft, the sliding device drives the centralizing blocks to descend synchronously with the rotating shaft, so that the centralizing blocks are in a relatively stationary position with the rotating shaft in the vertical direction. This avoids wear on the rotating shaft by the centralizing blocks when the rotating shaft slides down. This achieves both centralizing the rotating shaft and reducing wear on the rotating shaft in the vertical direction by the centralizing blocks, reducing the probability of the rotating shaft deviating during drilling, and thus improving drilling efficiency.

[0007] Preferably, the straightening blocks are divided into four groups, and each group of straightening blocks is provided with a corresponding sliding device. The sliding device includes a drive shaft, a driven shaft, and a sliding belt. The drive shaft and the driven shaft are rotatably connected to the support frame. The sliding belt is sleeved on the outside of the drive shaft and the driven shaft. The straightening block is fixedly connected to the sliding belt.

[0008] By adopting the above technical solution: the active shaft drives the sliding belt to slide evenly, the sliding belt drives the driven shaft to rotate, the sliding belt drives the slider to slide evenly, and the sliding belt drives the straightening block to descend evenly with the downward speed of the rotating shaft. At the same time, the sliding belt allows the slider to circulate in a circle under the drive of the sliding belt, making the contact and separation of the straightening block with the rotating shaft smoother. At the same time, when the straightening block is between the straightening belts of the active and driven shafts, the straightening block and the sliding belt are elastically connected, and the lateral vibration generated by the rotating shaft is absorbed by the sliding belt, avoiding hard contact between the straightening block and the rotating shaft, which would cause collision and damage to both.

[0009] Preferably, an anti-free-spinning assembly is provided between the drive shaft and the driven shaft and the sliding belt. The anti-free-spinning assembly includes a linkage groove formed on the outer wall of the drive shaft and the outer wall of the driven shaft, and a linkage bar fixedly connected to the inner wall of the sliding belt. The linkage bar is inserted into the linkage groove.

[0010] By adopting the above technical solution, the linkage bar and the linkage groove are connected and interlocked, so that when the drive shaft rotates, it drives the linkage bar to rotate, thereby causing the linkage bar to drive the sliding belt to rotate. This prevents relative sliding between the drive shaft and the driven shaft and the sliding belt, thus preventing the drive shaft from spinning freely.

[0011] Preferably, one group of the drive shafts is connected to a drive device for driving the drive shaft to rotate, and the other three groups of drive shafts are provided with a transmission device for transmitting rotation at the intersection of their ends.

[0012] Preferably, the driving device includes a driving component and a driving shaft. The driving component is fixedly connected to the support frame, one end of the driving shaft is fixedly connected to the output shaft of the driving component, and the other end is fixedly connected to the transmission shaft.

[0013] Preferably, the transmission device includes a first transmission bevel gear and a second transmission bevel gear, the first transmission bevel gear being fixedly connected to the drive shaft, the second transmission bevel gear being fixedly connected to the adjacent drive shaft, and the first transmission bevel gear meshing with the second transmission bevel gear.

[0014] By adopting the above technical solution: the driving component drives the driving shaft to rotate, the driving shaft drives the active shaft connected to it to rotate, the active shaft rotates to drive the first transmission bevel gear to rotate, the first transmission bevel gear drives the second transmission bevel gear meshing with it to rotate, the second transmission bevel gear drives the adjacent active shaft to rotate, and so on, so that all four active shafts rotate and drive the sliding belt to slide downward on the side close to the rotating shaft, thus realizing that the sliding belt drives all four sets of straightening blocks to slide downward with the rotating shaft.

[0015] Preferably, the straightening block is provided with a friction reduction component on the side near the rotating shaft. The friction reduction component includes a friction reduction groove and a friction reduction roller. The friction reduction groove is opened on the side of the straightening block near the rotating shaft. Several friction reduction rollers are provided. The several friction reduction rollers are evenly arrayed along the length direction of the friction reduction groove. Each friction reduction roller is rotatably connected to the friction reduction groove and abuts against the rotating shaft.

[0016] By adopting the above technical solution: when the straightening block contacts the rotating shaft, the rotating shaft drives the friction-reducing roller to rotate in the friction-reducing groove. The friction-reducing roller converts the sliding friction between the rotating shaft and the straightening block into rotational friction, reducing the wear of the rotating shaft during rotation and further improving the protection of the rotating shaft.

[0017] Preferably, a movable shaft is provided between the drive shaft and the driven shaft to keep the sliding belt in a taut state. The movable shaft drives the sliding belt to bulge on the side away from the rotation shaft. An elastic support device is provided between the movable shaft and the support frame. The elastic support device includes a support rod fixedly connected to the support frame, a support frame rotatably connected to the movable shaft, and an elastic connecting rod connecting the support rod and the support frame. The two ends of the elastic connecting rod are fixedly connected to the support rod and the support frame, respectively.

[0018] By adopting the above technical solution: when the rotating shaft vibrates laterally, it causes the sliding belt to move laterally, resulting in a convex deformation between the driving shaft and the driven shaft. At this time, the sliding belt drives the movable shaft to move closer to the support rod, and the movable shaft drives the elastic support rod to compress, thereby satisfying the deformation of the sliding belt on the side closer to the rotating shaft. When the force generated by the lateral vibration of the rotating shaft is removed, the compressed part of the elastic connecting rod recovers under the elastic action and pushes the movable shaft to slide away from the support rod, causing the movable shaft to drive the sliding belt on the side away from the rotating shaft to convex, thereby ensuring that the sliding belt on the side closer to the rotating shaft remains taut, so that the sliding belt drives the straightening block to abut against the rotating shaft, thus achieving both elastic contact between the straightening block and the rotating shaft and ensuring that the straightening block always abuts against the rotating shaft.

[0019] Preferably, the elastic connecting rod includes a first rod fixedly connected to the support rod, a second rod fixedly connected to the support frame, and an elastic element between the first rod and the second rod. The first rod has a sliding groove at one end away from the support rod, the second rod has one end away from the support frame located in the sliding groove, the elastic element is located in the sliding groove, and one end of the elastic element is fixedly connected to the bottom wall of the sliding groove, while the other end is fixedly connected to the second rod.

[0020] By adopting the above technical solution: when the movable axial support rod approaches, the movable shaft drives the support frame to approach the support rod, so that the support frame drives the second rod to slide in the sliding groove, and the second rod drives the elastic element to compress in the sliding groove; when the sliding band has no force to push the movable axial support rod closer, the elastic element recovers under its own elasticity, and the elastic element pushes the second rod to slide in the sliding groove, so that the second rod drives the support frame and the movable axial direction to slide away from the support rod.

[0021] Preferably, an auxiliary support device is provided on the outer side of the support frame. The auxiliary support device includes an auxiliary rod fixedly connected to the support frame and a crossbar disposed between the auxiliary rod and the support frame. One end of the auxiliary rod is fixedly connected to the top of the support frame, and the other end is fixedly connected to the working surface. The crossbar is horizontally arranged, and both ends of the crossbar are fixedly connected to the auxiliary rod and the support frame, respectively.

[0022] By adopting the above technical solution, the support frame is supported by auxiliary rods and crossbars, ensuring the stability of the entire device during the straightening process and improving the stability of the entire device during use.

[0023] The working principle and beneficial effects of this application are as follows: 1. By setting up a straightening block and a sliding device, the drive shaft is first moved into the support frame, so that the rotating shaft abuts against the straightening block. The rotating shaft is held vertically by several straightening blocks. At the same time, the arc groove on the straightening block increases the contact area with the rotating shaft, increasing the stability of the straightening block when straightening the rotating shaft. During the rotation and downward movement of the rotating shaft, the sliding device drives the straightening block to descend synchronously with the rotating shaft, so that the straightening block is in a relatively stationary position with the rotating shaft in the vertical direction. This avoids wear on the rotating shaft by the straightening block when the rotating shaft slides down. This achieves both straightening of the rotating shaft and reduction of wear on the rotating shaft in the vertical direction by the straightening block, reducing the probability of the rotating shaft deviating during drilling and thus improving drilling efficiency.

[0024] 2. By setting up an active shaft, a driven shaft, and a sliding belt, the active shaft drives the sliding belt to slide evenly, the sliding belt drives the driven shaft to rotate, and the sliding belt drives the slider to slide evenly. The sliding belt drives the straightening block to descend evenly with the downward speed of the rotating shaft. At the same time, the sliding belt allows the slider to circulate in a circular motion, making the contact and separation between the straightening block and the rotating shaft smoother. When the straightening block is between the straightening belt of the active shaft and the driven shaft, the straightening block and the sliding belt are elastically connected. The lateral vibration generated by the rotating shaft is absorbed by the sliding belt, avoiding hard contact between the straightening block and the rotating shaft, which would cause collision and damage to both.

[0025] 3. By setting up a movable shaft and an elastic support device, when the rotating shaft vibrates laterally, it causes the sliding belt to move laterally. The sliding belt deforms and protrudes between the driving shaft and the driven shaft. At this time, the sliding belt drives the movable shaft to move closer to the support rod. The movable shaft drives the elastic support rod to compress, thereby satisfying the deformation of the sliding belt on the side closer to the rotating shaft. When the force generated by the lateral vibration of the rotating shaft is removed, the compressed part of the elastic connecting rod recovers under the elastic action and pushes the movable shaft to slide away from the support rod. This causes the movable shaft to drive the sliding belt on the side away from the rotating shaft to protrude, thereby ensuring that the sliding belt on the side closer to the rotating shaft remains taut. This allows the sliding belt to drive the straightening block to abut against the rotating shaft, thus achieving both elastic contact between the straightening block and the rotating shaft and ensuring that the straightening block always abuts against the rotating shaft. Attached Figure Description

[0026] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] Figure 1 This is a schematic diagram of the structure of a top-drive drilling device according to this application; Figure 2 This application shows a schematic diagram of the structure of the drive device and the transmission device; Figure 3This application shows a schematic diagram of the sliding device. Figure 4 This application shows a structural schematic diagram of the elastic support device; Figure 5 This application shows a structural schematic diagram of the elastic connecting rod.

[0028] The technical features in the attached drawings are labeled as follows: 1. Support frame; 2. Straightening block; 3. Sliding device; 31. Drive shaft; 32. Driven shaft; 33. Sliding belt; 4. Anti-free-spinning assembly; 41. Linkage groove; 42. Linkage bar; 5. Drive device; 51. Drive component; 6. Transmission device; 61. First transmission bevel gear; 62. Second transmission bevel gear; 7. Anti-friction assembly; 71. Anti-friction groove; 72. Anti-friction roller; 8. Movable shaft; 9. Elastic support device; 91. Support rod; 92. Support frame; 93. Elastic connecting rod; 931. First rod; 932. Second rod; 933. Elastic element; 10. Auxiliary support device; 101. Auxiliary rod; 102. Crossbar. Detailed Implementation The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figures 1-2 As shown, this embodiment provides a top-drive drilling device, including a support frame 1 disposed on the working face, a straightening block 2 disposed within the support frame 1, and a sliding device 3 for driving the straightening block 2 to descend together with the rotating shaft. At least two straightening blocks 2 are provided, and the combined action of several straightening blocks 2 keeps the rotating shaft in a vertical state. Each straightening block 2 has an arc-shaped groove that abuts against the outer wall of the rotating shaft. In this embodiment, several straightening blocks 2 are provided, divided into four groups, with each group of straightening blocks 2 corresponding to a sliding device 3. Each straightening block 2 is fixedly connected to the sliding device 3. This embodiment can also use the device to straighten the drill pipe; whether to straighten the rotating shaft or the drill pipe can be determined based on the working environment of the construction site or the model of the top-drive drilling device.

[0030] like Figures 2-3As shown, the sliding device 3 includes a drive shaft 31, a driven shaft 32, and a sliding belt 33. Both the drive shaft 31 and the driven shaft 32 are rotatably connected to the support frame 1. The sliding belt 33 is sleeved on the outside of the drive shaft 31 and the driven shaft 32. The straightening block 2 is fixedly connected to the sliding belt 33. An anti-free-spinning component 4 is provided between the drive shaft 31, the driven shaft 32, and the sliding belt 33. The anti-free-spinning component 4 includes a linkage groove 41 that opens into the outer wall of the drive shaft 31 and the outer wall of the driven shaft 32, and a linkage bar 42 that is fixedly connected to the inner wall of the sliding belt 33. The linkage bar 42 is inserted into the linkage groove 41. A movable shaft 8 is provided between the drive shaft 31 and the driven shaft 32 to keep the sliding belt 33 in a taut state. The movable shaft 8 drives the sliding belt 33 on the side away from the rotation axis to protrude. An elastic support device 9 is provided between the movable shaft 8 and the support frame 1 to automatically adjust the distance between the movable shaft 8 and the support rod 91.

[0031] like Figures 2-3 As shown, one set of drive shafts 31 is connected to a drive device 5 for driving the drive shaft 31 to rotate, and the other three sets of drive shafts 31 are all provided with transmission devices 6 for transmitting rotation at their intersection. The drive device 5 includes a drive member 51 and a drive shaft. The drive member 51 is fixedly connected to the support frame 1. One end of the drive shaft is fixedly connected to the output shaft of the drive member 51, and the other end is fixedly connected to the transmission shaft. The transmission device 6 includes a first transmission bevel gear 61 and a second transmission bevel gear 62. The first transmission bevel gear 61 is fixedly connected to the drive shaft 31, and the second transmission bevel gear 62 is fixedly connected to the adjacent drive shaft 31. The first transmission bevel gear 61 and the second transmission bevel gear 62 mesh.

[0032] like Figures 3-4 As shown, a friction reduction component 7 is provided on the side of the straightening block 2 near the rotating shaft. The friction reduction component 7 includes a friction reduction groove 71 and a friction reduction roller 72. The friction reduction groove 71 is opened on the side of the straightening block 2 near the rotating shaft. Several friction reduction rollers 72 are provided. The several friction reduction rollers 72 are evenly arrayed along the length direction of the friction reduction groove 71. Each friction reduction roller 72 is rotatably connected to the friction reduction groove 71 and abuts against the rotating shaft.

[0033] like Figures 4-5As shown, the elastic support device 9 includes a support rod 91 fixedly connected to the support frame 1, a support frame 92 rotatably connected to the movable shaft 8, and an elastic connecting rod 93 connecting the support rod 91 and the support frame 92. The two ends of the elastic connecting rod 93 are fixedly connected to the support rod 91 and the support frame 92, respectively. The elastic connecting rod 93 includes a first rod 931 fixedly connected to the support rod 91, a second rod 932 fixedly connected to the support frame 92, and an elastic element 933 between the first rod 931 and the second rod 932. A sliding groove is provided at the end of the first rod 931 away from the support rod 91. The end of the second rod 932 away from the support frame 92 is located in the sliding groove. The elastic element 933 is located in the sliding groove, and one end of the elastic element 933 is fixedly connected to the bottom wall of the sliding groove, while the other end is fixedly connected to the second rod 932.

[0034] like Figures 3-4 As shown, an auxiliary support device 10 is provided on the outside of the support frame 1. The auxiliary support device 10 includes an auxiliary rod 101 fixedly connected to the support frame 1 and a crossbar 102 disposed between the auxiliary rod 101 and the support frame 1. One end of the auxiliary rod 101 is fixedly connected to the top of the support frame 1, and the other end is fixedly connected to the working surface. The crossbar 102 is horizontally disposed, and both ends of the crossbar 102 are fixedly connected to the auxiliary rod 101 and the support frame 1, respectively.

[0035] The basic principle of this embodiment is as follows: When using the drilling device of this application, firstly, the drive shaft is moved into the support frame 1 so that the rotating shaft contacts the four straightening blocks 2, making the rotating shaft vertical. Then, when the top drive device 5 is activated to drive the rotating shaft to rotate, the rotating shaft drives the anti-friction roller 72 to rotate in the anti-friction groove 71. As the rotating shaft descends, the drive unit 51 is activated to drive the drive shaft 31 to rotate. The drive shaft 31 drives the second drive bevel gear 62 meshing with it to rotate through the first drive bevel gear 61. The second drive bevel gear 62 drives the adjacent drive shaft 31 to rotate, and so on. All four drive shafts 31 rotate. The drive shafts 31, through the limiting action of the linkage bar 42 and the linkage groove 41, drive the sliding belt 33 to slide downward on the side close to the rotating shaft. The sliding belt 33 drives the straightening block 2 to descend synchronously with the descent of the rotating shaft, so that the straightening block 2 is in a relatively stationary position with the rotating shaft in the vertical direction. This avoids the wear of the straightening block 2 on the rotating shaft when the rotating shaft slides down. It can both straighten the rotating shaft and reduce the wear of the straightening block 2 on the rotating shaft in the vertical direction, thereby reducing the probability of the rotating shaft deviating during drilling and achieving the purpose of improving drilling efficiency.

[0036] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A top-drive drilling device, characterized in that, It includes a support frame (1) set on the working surface, a straightening block (2) set in the support frame (1), and a sliding device (3) for driving the straightening block (2) to descend together with the rotating shaft. There are at least two straightening blocks (2). Several straightening blocks (2) work together to keep the rotating shaft in a vertical state. Each straightening block (2) is provided with an arc-shaped groove, which abuts against the outer wall of the rotating shaft. The straightening block (2) is fixedly connected to the sliding device (3).

2. The top-drive drilling apparatus according to claim 1, characterized in that, The straightening block (2) is divided into four groups. Each group of straightening blocks (2) is provided with a corresponding sliding device (3). The sliding device (3) includes a drive shaft (31), a driven shaft (32) and a sliding belt (33). The drive shaft (31) and the driven shaft (32) are rotatably connected to the support frame (1). The sliding belt (33) is sleeved on the outside of the drive shaft (31) and the driven shaft (32). The straightening block (2) is fixedly connected to the sliding belt (33).

3. A top-drive drilling apparatus according to claim 2, characterized in that, An anti-free rotation assembly (4) is provided between the drive shaft (31) and the driven shaft (32) and the sliding belt (33). The anti-free rotation assembly (4) includes a linkage groove (41) formed on the outer wall of the drive shaft (31) and the outer wall of the driven shaft (32), and a linkage bar (42) fixedly connected to the inner wall of the sliding belt (33). The linkage bar (42) is inserted into the linkage groove (41).

4. A top-drive drilling apparatus according to claim 3, characterized in that, One of the drive shafts (31) is connected to a drive device (5) for driving the drive shaft (31) to rotate, and the other three drive shafts (31) are provided with a transmission device (6) for transmitting rotation at the intersection of their ends.

5. A top-drive drilling apparatus according to claim 4, characterized in that, The drive device (5) includes a drive component (51) and a drive shaft. The drive component (51) is fixedly connected to the support frame (1). One end of the drive shaft is fixedly connected to the output shaft of the drive component (51), and the other end is fixedly connected to the transmission shaft.

6. A top-drive drilling apparatus according to claim 4, characterized in that, The transmission device (6) includes a first transmission bevel gear (61) and a second transmission bevel gear (62). The first transmission bevel gear (61) is fixedly connected to the drive shaft (31), and the second transmission bevel gear (62) is fixedly connected to the adjacent drive shaft (31). The first transmission bevel gear (61) and the second transmission bevel gear (62) mesh.

7. A top-drive drilling apparatus according to claim 2, characterized in that, The straightening block (2) is provided with a friction reduction component (7) on the side near the rotating shaft. The friction reduction component (7) includes a friction reduction groove (71) and a friction reduction roller (72). The friction reduction groove (71) is opened on the side of the straightening block (2) near the rotating shaft. There are several friction reduction rollers (72). The several friction reduction rollers (72) are evenly arrayed along the length direction of the friction reduction groove (71). Each friction reduction roller (72) is rotatably connected to the friction reduction groove (71) and abuts against the rotating shaft.

8. A top-drive drilling apparatus according to claim 2, characterized in that, A movable shaft (8) is provided between the drive shaft (31) and the driven shaft (32) to keep the sliding belt (33) in a taut state. The movable shaft (8) causes the sliding belt (33) away from the rotating shaft to bulge. An elastic support device (9) is provided between the movable shaft (8) and the support frame (1). The elastic support device (9) includes a support rod (91) fixedly connected to the support frame (1), a support frame (92) rotatably connected to the movable shaft (8), and an elastic connecting rod (93) connecting the support rod (91) and the support frame (92). The two ends of the elastic connecting rod (93) are fixedly connected to the support rod (91) and the support frame (92) respectively.

9. A top-drive drilling apparatus according to claim 8, characterized in that, The elastic connecting rod (93) includes a first rod (931) fixedly connected to the support rod (91), a second rod (932) fixedly connected to the support frame (92), and an elastic element (933) between the first rod (931) and the second rod (932). The first rod (931) has a sliding groove at one end away from the support rod (91), and the second rod (932) has one end away from the support frame (92) located in the sliding groove. The elastic element (933) is located in the sliding groove, and one end of the elastic element (933) is fixedly connected to the bottom wall of the sliding groove, and the other end is fixedly connected to the second rod (932).

10. A top-drive drilling apparatus according to claim 1, characterized in that, An auxiliary support device (10) is provided on the outside of the support frame (1). The auxiliary support device (10) includes an auxiliary rod (101) fixedly connected to the support frame (1) and a crossbar (102) disposed between the auxiliary rod (101) and the support frame (1). One end of the auxiliary rod (101) is fixedly connected to the top of the support frame (1) and the other end is fixedly connected to the working surface. The crossbar (102) is horizontally disposed, and both ends of the crossbar (102) are fixedly connected to the auxiliary rod (101) and the support frame (1) respectively.

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