Paver for proppant detection

Abstract

The spreading device for proppant detection comprises a detection container, the top of the detection container is open, a mounting rod is slidably arranged on the top of the detection container in the horizontal direction, a mounting block is slidably arranged on the mounting rod in the length direction of the mounting rod, and a blanking device is arranged on the mounting block; the detection container is provided with a first driving assembly, the first driving assembly is used for driving the mounting rod to move on the detection container, the mounting rod is provided with a second driving assembly, and the second driving assembly is used for driving the mounting block to move on the mounting rod; the first driving assembly and the second driving assembly are in transmission connection through a transmission assembly, a flattening plate is rotationally arranged at the bottom of the mounting block, a rotating piece is arranged on the mounting block, and the rotating piece is used for driving the flattening plate to rotate on the mounting block, and the labor intensity of workers can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of proppant detection, and in particular, to a proppant detection spreader. Background Art

[0002] The contents of this section merely provide background information related to the present application and may not constitute prior art.

[0003] Fracturing is an important technology for increasing the production of low-permeability oil and gas wells. Fracturing proppants are key materials for fracturing construction. The function of fracturing proppants is to support the cracks in the fracturing formation, thereby effectively introducing oil and gas into the oil and gas wells, greatly increasing oil and gas production and extending the life of the oil wells. Usually, fracturing proppants are natural sands or artificial high-strength ceramic particles with a certain particle size and grading.

[0004] Proppant has become one of the most widely used fracturing support materials due to its good strength and corrosion resistance. In order to ensure its performance in fracturing operations, the proppant must undergo a series of rigorous tests. When testing the proppant, the proppant needs to be evenly laid in the testing equipment to test its pressure or corrosion resistance.

[0005] The usual method of proppant laying is for workers to pour the proppant into a test container and then spread the proppant flat. However, during the long test process, workers are required to perform frequent operations, which brings a certain workload to the workers. Summary of the invention

[0006] In order to solve the above technical problems, the purpose of the present application is to provide a proppant detection spreader that can effectively reduce the labor intensity of the staff.

[0007] The purpose of this application is achieved through the following technical solutions: A proppant detection spreader comprises a detection container, the top opening of the detection container is provided, a mounting rod is slidably provided in a horizontal direction on the top of the detection container, a mounting block is slidably provided on the mounting rod along the length direction of the mounting rod, a dropper is provided on the mounting block, a first driving assembly is provided on the detection container, the first driving assembly is used to drive the mounting rod to move on the detection container, a second driving assembly is provided on the mounting rod, the second driving assembly is used to drive the mounting block to move on the mounting rod, the first driving assembly and the second driving assembly are connected through a transmission assembly, a spreading plate is rotatably provided at the bottom of the mounting block, a rotating member is provided on the mounting block, and the rotating member is used to drive the spreading plate to rotate on the mounting block.

[0008] In some possible embodiments, the first driving assembly includes a driving motor and a first driving screw, a first slide groove is opened in a horizontal direction on the side wall of the detection container, a first slider is slidably arranged in the first slide groove, the first slider is connected to the side end of the mounting rod, the first driving screw is rotatably arranged in the first slide groove along the length direction of the first slide groove, the driving motor is fixedly arranged on the side wall of the detection container, the first driving screw is drivingly connected to the output shaft of the driving motor, the first slider is threadedly sleeved on the first driving screw, and the transmission assembly is arranged on the first slider.

[0009] In some possible embodiments, the second driving component includes a driving shaft and a second driving screw, a second slide groove is opened on the mounting rod along the length direction of the mounting rod, the top of the second slide groove is penetrated, a second slider is slidably arranged in the second slide groove, the second driving screw is rotatably arranged in the second slide groove along the length direction of the second slide groove, the second slider is threadedly sleeved on the second driving screw, the driving shaft is rotatably arranged on the mounting rod, the driving shaft is coaxially fixedly connected with the second driving screw, one end of the transmission assembly is transmission-connected to the driving shaft, and the other end is transmission-connected to the first driving screw, and the mounting block is arranged at the bottom of the second slider.

[0010] In some possible embodiments, the transmission assembly includes a first transmission gear and a second transmission gear, a receiving hole is opened on the slider, the first transmission gear is rotatably arranged on the side wall of the accommodating hole, a threaded hole is opened on the first transmission gear and is engaged with the thread of the first driving screw, a transmission shaft is rotatably arranged on the side wall of the slider, the transmission shaft is coaxially connected with the driving shaft, the second transmission gear is coaxially fixed on the transmission shaft, the axis of the second transmission gear is perpendicular to the axis of the first transmission gear, and the second transmission gear is engaged with the first transmission gear.

[0011] In some possible embodiments, two first transmission gears are provided, and the two first transmission gears are symmetrically arranged on the two side walls of the accommodating hole along the axial direction of the transmission shaft. The two first transmission gears are both meshed with the second transmission gear, and the spiral grooves of the threaded holes on the two first transmission gears have opposite rotation directions.

[0012] In some possible embodiments, a guide groove is opened on the side wall of the second slide groove, a guide block is slidably arranged in the guide groove, the guide block is fixedly connected to the side wall of the second slider, a sliding layer is covered on the side wall of the guide block, and the sliding layer is used to be slidably connected to the inner wall of the guide groove.

[0013] In some possible embodiments, the rotating member is configured as a mounting shaft, a mounting hole is opened in the vertical direction on the mounting block, a mounting shaft is rotatably arranged in the mounting hole, the bottom end of the mounting shaft extends out of the mounting hole, the spreading plate is fixedly arranged at the bottom of the mounting shaft, a driving rod is arranged at the top of the mounting shaft, the driving rod is used to drive the mounting shaft to rotate, a limiting member is arranged on the driving rod, and the limiting member is used to limit the deflection angle of the mounting shaft.

[0014] In some possible embodiments, the limiting member is configured as a limiting sleeve, and the limiting sleeve is slidably sleeved on the top of the driving rod in the vertical direction, and a limiting tooth is fixedly arranged at the bottom of the limiting sleeve, and a plurality of limiting teeth are evenly arranged along the circumference of the limiting sleeve, a limiting groove is opened on the top of the mounting block, the mounting hole is opened at the bottom of the limiting groove, and a groove for the limiting tooth to be inserted is opened on the inner wall of the limiting groove, and an elastic member is arranged on the driving rod, and the elastic member is used to drive the limiting sleeve to move toward the limiting groove.

[0015] In some possible embodiments, a socket is provided at the bottom of the limiting sleeve, the cross-section of the socket is set to be rectangular, the cross-section of the driving rod is adapted to the socket, the elastic member is set to be a tension spring, the elastic member is arranged in the socket, one end of the elastic member is fixedly connected to the inner wall of the socket, and the other end is fixedly connected to the end of the driving rod.

[0016] In some possible embodiments, an anti-slip sleeve is sleeved on the outer peripheral wall of the limiting sleeve, and anti-slip stripes are arranged on the outer side wall of the anti-slip sleeve.

[0017] In summary, the technical solution of the embodiment of the present application has at least the following advantages and beneficial effects: 1. In actual use, the first driving assembly is started to drive the installation rod to move, and the second driving assembly can be driven by the first transmission gear and the second transmission gear to drive the installation block to move on the installation rod. With the movement of the installation block, the dropper can be driven to move in the detection container, so as to achieve uniform drop. When the drop is completed, the dropped proppant can be flattened by the flat plate, without the need for manual drop and flattening by the staff, which effectively reduces the labor intensity of the staff; 2. With the rotation of the first driving screw, the first transmission gear is driven to rotate on the slider, and with the rotation of the first transmission gear, the second transmission gear can be driven to rotate, and with the rotation of the second transmission gear, the second driving screw can be driven to rotate, and then the second slider can be driven to move in the second slide slot, thereby achieving the purpose of driving the mounting block to move on the mounting rod; 3. When the second slider moves in the second slide groove, the second slider drives the guide block to move in the guide groove. The guide block not only supports the movement of the second slider in the second slide groove, but also guides the movement of the second slider, thereby improving the movement accuracy of the second slider; 4. By limiting the different deflection angles of the installation axis through the limiter, the rotation angle of the spreading plate can be adjusted, and then it can correspond to different moving speeds of the installation block to ensure a good spreading effect on the proppant, further improving the accuracy and precision of the proppant detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application; Figure 2 This is a schematic diagram of the structure of the first drive assembly and the second drive assembly of an embodiment of the present application; Figure 3 A cross-sectional view of a first sliding block according to an embodiment of the present application; Figure 4 for Figure 3 A magnified view of part A in FIG. Figure 5 A schematic diagram of the structure of a rotating member in an embodiment of the present application; Figure 6 for Figure 5 Enlarged view of part B in .

[0019] Icons: 1. Detection container; 11. Container part; 12. Mounting frame; 2. Mounting rod; 21. Mounting block; 22. Dropper; 23. Spreading plate; 3. First drive assembly; 31. Drive motor; 32. First drive screw; 33. First slide groove; 34. First slider; 4. Second drive assembly; 41. Drive shaft; 42. Second drive screw; 43. Second slide groove; 44. Second slider; 45. Guide groove; 46. Guide block; 5. Rotating member; 51. Mounting hole; 52. Drive rod; 53. Limiting member; 54. Limiting tooth; 55. Limiting groove; 56. Slot; 57. Elastic member; 58. Socket; 6. Transmission assembly; 61. First transmission gear; 62. Second transmission gear; 63. Receiving hole; 64. Transmission shaft. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] The following reference Figures 1 to 6 This application is described in further detail.

[0022] Reference Figure 1 A proppant testing device comprises a testing container 1, wherein the top opening of the testing container 1 is provided, wherein Figure 1 As an embodiment of the present application, the detection container 1 includes a container part 11 and a mounting frame 12, the mounting frame 12 is fixedly arranged on the container part 11, the mounting rod 2 is slidably arranged in the mounting frame 12, and a mounting block 21 is slidably arranged on the mounting rod 2 along the length direction of the mounting rod 2, and a dropper 22 is arranged on the mounting block 21.

[0023] Reference Figure 1 , 2 A first driving assembly 3 is provided on the detection container 1, and the first driving assembly 3 is used to drive the mounting rod 2 to move on the detection container 1. A second driving assembly 4 is provided on the mounting rod 2, and the second driving assembly 4 is used to drive the mounting block 21 to move on the mounting rod 2. The first driving assembly 3 and the second driving assembly 4 are connected through a transmission assembly 6 for transmission.

[0024] Reference Figure 3 , 5 A spreading plate 23 is rotatably arranged at the bottom of the mounting block 21 , and a rotating member 5 is arranged on the mounting block 21 , and the rotating member 5 is used to drive the spreading plate 23 to rotate on the mounting block 21 .

[0025] Among them, refer to Figure 2 As an embodiment of the present application, the first driving assembly 3 includes a driving motor 31 and a first driving screw 32. A first sliding groove 33 is opened in the horizontal direction on the side wall of the detection container 1. A first slider 34 is slidably arranged in the first sliding groove 33. The first slider 34 is connected to the side end of the mounting rod 2. The first driving screw 32 is rotatably arranged in the first sliding groove 33 along the length direction of the first sliding groove 33. The driving motor 31 is fixedly arranged on the side wall of the detection container 1. The first driving screw 32 is transmission-connected to the output shaft of the driving motor 31. The first slider 34 is threadedly sleeved on the first driving screw 32. The transmission assembly 6 is arranged on the first slider 34.

[0026] During actual use, starting the drive motor 31 can drive the first drive screw 32 to rotate in the first slide groove 33. As the first drive screw 32 rotates, the first slider 34 is driven to move in the first slide groove 33. The transmission is carried out through the mutually engaged threads between the first slider 34 and the first drive screw 32, and the transmission is more stable, accurate and reliable, with good practicality and reliability.

[0027] Reference Figure 2 , 3As an embodiment of the present application, the second driving assembly 4 includes a driving shaft 41 and a second driving screw 42. A second slide groove 43 is opened on the mounting rod 2 along the length direction of the mounting rod 2. The top of the second slide groove 43 is penetrated, and a second slider 44 is slidably arranged in the second slide groove 43. The second driving screw 42 is rotatably arranged in the second slide groove 43 along the length direction of the second slide groove 43. The second slider 44 is threadedly sleeved on the second driving screw 42. The driving shaft 41 is rotatably arranged on the mounting rod 2. The driving shaft 41 is coaxially fixedly connected with the second driving screw 42. One end of the transmission assembly 6 is transmission-connected to the driving shaft 41, and the other end is transmission-connected to the first driving screw 32. The mounting block 21 is arranged at the bottom of the second slider 44.

[0028] In actual use, the first driving assembly 3 is started to drive the installation rod 2 to move, and the second driving assembly 4 can be driven by the first transmission gear 61 and the second transmission gear 62 to drive the installation block 21 to move on the installation rod 2. As the installation block 21 moves, the dropper 22 can be driven to move in the detection container 1, so as to achieve uniform drop of materials. When the drop of materials is completed, the dropped proppant can be flattened by the flattening plate 23, without the need for manual drop and flattening by the staff, which effectively reduces the labor intensity of the staff. As an implementation method of this application, refer to Figure 3 , 4 The transmission assembly 6 includes a first transmission gear 61 and a second transmission gear 62. A receiving hole 63 is opened on the slider. The first transmission gear 61 is rotatably set on the side wall of the receiving hole 63. A threaded hole that is threadedly engaged with the first driving screw 32 is opened on the first transmission gear 61. A transmission shaft 64 is rotatably set on the side wall of the slider. The transmission shaft 64 is coaxially connected to the driving shaft 41. The second transmission gear 62 is coaxially fixed on the transmission shaft 64. The axis of the second transmission gear 62 is perpendicular to the axis of the first transmission gear 61, and the second transmission gear 62 is meshed with the first transmission gear 61.

[0029] Among them, refer to Figure 4 As an embodiment of the present application, two first transmission gears 61 are provided. The two first transmission gears 61 are symmetrically arranged on the two side walls of the accommodating hole 63 along the axial direction of the transmission shaft 64. The two first transmission gears 61 are both engaged with the second transmission gear 62. The spiral grooves of the threaded holes on the two first transmission gears 61 rotate in opposite directions. As the first driving screw 32 rotates, the two first transmission gears 61 can be driven to rotate in opposite directions in the accommodating hole 63, thereby driving the second transmission gear 62 to rotate. By arranging the first transmission gears 61 at both ends of the second transmission gear 62, not only the transmission stability of the second transmission gear 62 is improved, but also the overall stability and reliability of the device are guaranteed.

[0030] Reference Figure 3 As an embodiment of the present application, a guide groove 45 is opened on the side wall of the second slide groove 43, and a guide block 46 is slidably arranged in the guide groove 45. The guide block 46 is fixedly connected to the side wall of the second slider 44, and a sliding layer is covered on the side wall of the guide block 46, and the sliding layer is used to be slidably connected to the inner wall of the guide groove 45.

[0031] When the second slider 44 moves in the second slide groove 43, as the second slider 44 drives the guide block 46 to move in the guide groove 45, the guide block 46 not only supports the movement of the second slider 44 in the second slide groove 43, but also guides the movement of the second slider 44, thereby improving the movement accuracy of the second slider 44. Reference Figure 5 , 6 The rotating member 5 is arranged as a mounting shaft, a mounting hole 51 is provided on the mounting block 21 in the vertical direction, a mounting shaft is rotatably arranged in the mounting hole 51, the bottom end of the mounting shaft extends out of the mounting hole 51, the spreading plate 23 is fixedly arranged at the bottom of the mounting shaft, a driving rod 52 is arranged at the top of the mounting shaft, the driving rod 52 is used to drive the mounting shaft to rotate, a limiting member 53 is arranged on the driving rod 52, and the limiting member 53 is used to limit the deflection angle of the mounting shaft.

[0032] Reference Figure 5 , 6 As an implementation mode of the present application, the limiting member 53 is configured as a limiting sleeve, which is slidably sleeved on the top of the driving rod 52 in the vertical direction, and a limiting clamping tooth 54 is fixedly arranged at the bottom of the limiting sleeve. A plurality of limiting clamping teeth 54 are evenly arranged along the circumference of the limiting sleeve, and a limiting groove 55 is opened on the top of the mounting block 21. The mounting hole 51 is opened at the bottom of the limiting groove 55. A clamping groove 56 for the limiting clamping tooth 54 to be inserted is opened on the inner wall of the limiting groove 55. An elastic member 57 is arranged on the driving rod 52, and the elastic member 57 is used to drive the limiting sleeve to move toward the limiting groove 55.

[0033] By limiting the different deflection angles of the installation axis through the limiter 53, the rotation angle of the spreading plate 23 can be adjusted, and then it can correspond to different moving speeds of the installation block 21 to ensure a good spreading effect on the proppant, further improving the accuracy and precision of the proppant detection.

[0034] Reference Figure 5 , 6As an embodiment of the present application, a socket 58 is provided at the bottom of the limiting sleeve, the cross-section of the socket 58 is set to be rectangular, the cross-section of the driving rod 52 is adapted to the socket 58, the elastic member 57 is set to be a tension spring, the elastic member 57 is arranged in the socket 58, one end of the elastic member 57 is fixedly connected to the inner wall of the socket 58, and the other end is fixedly connected to the end of the driving rod 52.

[0035] As a possible implementation of the present application, an anti-slip sleeve (not shown in the figure) is sleeved on the outer peripheral wall of the limiting sleeve, and anti-slip stripes are arranged on the outer side wall of the anti-slip sleeve. The material of the anti-slip sleeve is set to silicone rubber, which has good material performance stability.

[0036] The implementation principle of a proppant detection spreader proposed in the embodiment of the present application is: During actual use, the first drive assembly 3 is started to drive the installation rod 2 to move, and the second drive assembly 4 can be driven by the first transmission gear 61 and the second transmission gear 62 to drive the installation block 21 to move on the installation rod 2. As the installation block 21 moves, the dropper 22 can be driven to move in the detection container 1, thereby achieving uniform drop of materials. When the drop of materials is completed, the fallen proppant can be flattened by the spreading plate 23, without the need for manual drop and flattening by the staff, which effectively reduces the labor intensity of the staff.

[0037] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A proppant testing device, characterized in that: The invention comprises a detection container (1), wherein the top of the detection container (1) is provided with an opening, a mounting rod (2) is slidably provided at the top of the detection container (1) in a horizontal direction, a mounting block (21) is slidably provided on the mounting rod (2) in a length direction of the mounting rod (2), a material dropper (22) is provided on the mounting block (21), a first driving assembly (3) is provided on the detection container (1), the first driving assembly (3) is used to drive the mounting rod (2) to move on the detection container (1), a second driving assembly (4) is provided on the mounting rod (2), the second driving assembly (4) is used to drive the mounting block (21) to move on the mounting rod (2), the first driving assembly (3) and the second driving assembly (4) are connected to each other through a transmission assembly (6), a spreading plate (23) is rotatably provided at the bottom of the mounting block (21), a rotating member (5) is provided on the mounting block (21), the rotating member (5) is used to drive the spreading plate (23) to rotate on the mounting block (21).

2. A proppant detection placing device according to claim 1, characterized in that: The first driving assembly (3) comprises a driving motor (31) and a first driving screw (32). A first sliding groove (33) is provided on the side wall of the detection container (1) in a horizontal direction. A first sliding block (34) is slidably arranged in the first sliding groove (33). The first sliding block (34) is connected to the side end of the mounting rod (2). The first driving screw (32) is rotatably arranged in the first sliding groove (33) along the length direction of the first sliding groove (33). The driving motor (31) is fixedly arranged on the side wall of the detection container (1). The first driving screw (32) is drivingly connected to the output shaft of the driving motor (31). The first sliding block (34) is threadedly sleeved on the first driving screw (32). The transmission assembly (6) is arranged on the first sliding block (34).

3. A proppant detection placing device according to claim 2, characterized in that: The second driving assembly (4) comprises a driving shaft (41) and a second driving screw (42). A second slide groove (43) is provided on the mounting rod (2) along the length direction of the mounting rod (2). The top of the second slide groove (43) is penetrated. A second slider (44) is slidably provided in the second slide groove (43). The second driving screw (42) is rotatably provided in the second slide groove (43) along the length direction of the second slide groove (43). The second slider (44) is threadedly sleeved on the second driving screw (42). The driving shaft (41) is rotatably provided on the mounting rod (2). The driving shaft (41) and the second driving screw (42) are coaxially fixedly connected. One end of the transmission assembly (6) is transmission-connected to the driving shaft (41), and the other end is transmission-connected to the first driving screw (32). The mounting block (21) is provided at the bottom of the second slider (44).

4. A proppant detection placing device according to claim 3, characterized in that: The transmission assembly (6) comprises a first transmission gear (61) and a second transmission gear (62); a receiving hole (63) is provided on the slider; the first transmission gear (61) is rotatably arranged on the side wall of the receiving hole (63); a threaded hole is provided on the first transmission gear (61) and is threadedly engaged with the first driving screw (32); a transmission shaft (64) is rotatably arranged on the side wall of the slider; the transmission shaft (64) is coaxially connected to the driving shaft (41); the second transmission gear (62) is coaxially fixedly sleeved on the transmission shaft (64); the axis of the second transmission gear (62) is perpendicular to the axis of the first transmission gear (61); and the second transmission gear (62) and the first transmission gear (61) are meshed with each other.

5. A proppant detection placing device according to claim 4, characterized in that: Two first transmission gears (61) are provided, and the two first transmission gears (61) are symmetrically arranged on the two side walls of the accommodating hole (63) along the axial direction of the transmission shaft (64). The two first transmission gears (61) are both meshed with the second transmission gear (62), and the spiral grooves of the threaded holes on the two first transmission gears (61) have opposite rotation directions.

6. A proppant detection placing device according to claim 3, characterized in that: A guide groove (45) is provided on the side wall of the second slide groove (43), a guide block (46) is slidably arranged in the guide groove (45), the guide block (46) is fixedly connected to the side wall of the second slide block (44), and a sliding layer is covered on the side wall of the guide block (46), the sliding layer is used to be slidably connected to the inner wall of the guide groove (45).

7. A proppant detection placing device according to claim 1, characterized in that: The rotating member (5) is arranged as a mounting shaft, a mounting hole (51) is provided on the mounting block (21) in a vertical direction, a mounting shaft is rotatably arranged in the mounting hole (51), the bottom end of the mounting shaft extends out of the mounting hole (51), the spreading plate (23) is fixedly arranged at the bottom of the mounting shaft, a driving rod (52) is arranged at the top of the mounting shaft, the driving rod (52) is used to drive the mounting shaft to rotate, a limiting member (53) is arranged on the driving rod (52), and the limiting member (53) is used to limit the deflection angle of the mounting shaft.

8. A proppant detection placing device according to claim 7, characterized in that: The limiting member (53) is configured as a limiting sleeve, the limiting sleeve is slidably sleeved on the top of the driving rod (52) in the vertical direction, a limiting clamping tooth (54) is fixedly arranged at the bottom of the limiting sleeve, a plurality of the limiting clamping teeth (54) are evenly arranged along the circumference of the limiting sleeve, a limiting groove (55) is provided at the top of the mounting block (21), the mounting hole (51) is provided at the bottom of the limiting groove (55), a clamping groove (56) for the limiting clamping tooth (54) to be clamped is provided on the inner wall of the limiting groove (55), and an elastic member (57) is provided on the driving rod (52), the elastic member (57) is used to drive the limiting sleeve to move toward the limiting groove (55).

9. A proppant detection placing device according to claim 8, characterized in that: A socket (58) is provided at the bottom of the limiting sleeve, the cross section of the socket (58) is arranged to be rectangular, the cross section of the driving rod (52) is adapted to the socket (58), the elastic member (57) is arranged to be a tension spring, the elastic member (57) is arranged in the socket (58), one end of the elastic member (57) is fixedly connected to the inner wall of the socket (58), and the other end is fixedly connected to the end of the driving rod (52).

10. A proppant detection placing device according to claim 9, characterized in that: An anti-skid sleeve is sleeved on the outer peripheral wall of the limiting sleeve, and anti-skid stripes are arranged on the outer side wall of the anti-skid sleeve.

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