Geographic surveying and mapping sampling device for bridge construction

Abstract

The invention relates to the technical field of geographic surveying and mapping sampling, in particular to a bridge construction geographic surveying and mapping sampling device which comprises a first rotating part, a second rotating part, a third rotating part and a fourth rotating part. The base is provided with a lower inlet, the top cover is provided with an upper outlet, and a discharge channel is arranged between the outer shell and the top cover. The second rotating piece comprises an inner blocking piece and an inner shell arranged on the inner blocking piece, a containing channel is formed between the inner blocking piece and the inner shell, and the second rotating piece further comprises an isolation arc piece arranged on the inner blocking piece; sludge cannot be extruded in the insertion process, the accuracy of a sample can be improved, during primary sampling, the sludge located in the containing channel is a sludge sample directly inserted into the corresponding depth, and the sludge sample on the other side is a sludge sample subjected to slight precipitation; the sampling diversity can be improved while the accuracy of the sampled sample is ensured, and the sampling personnel can conveniently compare.

Description

Technical Field

[0001] The present invention relates to the technical field of geodetic surveying and sampling, and in particular to a geodetic surveying and sampling device for bridge construction. Background Art

[0002] During the bridge construction and operation stages, it is necessary to evaluate the physical and mechanical properties of the silt layer under the foundation through geological surveying, such as moisture content, compression modulus, etc. Among them, silt sampling in the river channel is a key link. In conventional sampling devices, a grab-type sampler is suitable for the rapid collection of silt within the surface layer, but it is difficult to obtain deep samples; the insert-type sampler is divided into two categories: one is the negative pressure pump suction type, which is suitable for the shallow and rapid sampling of fluid-like silt, but it is easy to cause sample disturbance, loss of fine particles, and moisture content deviation; the other is the gravity piston type, which relies on its own weight or mechanical pressure to insert the sampling tube into the formation and keeps the sample in its original state through a piston, and can obtain deep original silt, but the equipment structure is complex and the sampling efficiency is low.

[0003] Due to the significant differences in the sample characteristics of the two insert-type methods, such as the higher sample disturbance of the pump suction type and the smaller disturbance rate of the piston type, but the internal silt composition may be unstable during the sampling process of the piston type due to the extrusion process. In engineering, two types of devices need to be used for sampling respectively for comparative analysis, resulting in the need to carry multiple devices and conduct multiple measurements for a single operation. Therefore, the present invention proposes a geodetic surveying and sampling device for bridge construction. Summary of the Invention

[0004] In view of the problem in the above or the prior art that in order to ensure the accuracy of the sample, multiple devices need to be carried and multiple measurements need to be conducted for a single operation, the present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a geodetic surveying and sampling device for bridge construction.

[0006] To solve the above technical problems, the present invention provides the following technical solution: A geodetic surveying and sampling device for bridge construction, comprising a first rotating member, which includes a base and a top cover, and an outer housing disposed between the base and the top cover; a lower inlet is provided on the base, an upper discharge port is provided on the top cover, and a discharge channel is provided between the outer housing and the top cover; a second rotating member, which includes an inner baffle and an inner housing disposed on the inner baffle, a receiving channel is formed between the inner baffle and the inner housing, and an isolation arc is further provided on the inner baffle; when the receiving channel is aligned with the lower inlet and the discharge channel, silt can enter the discharge channel through the lower inlet, and relative rotation of the first rotating member and the second rotating member can cause the isolation arc to block the discharge channel.

[0007] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: the lower inlet and the upper discharge outlet are located on different sides of the inner baffle; the discharge channel and the upper discharge outlet are located on different sides of the inner baffle; the isolation arc plate and the accommodation channel are located on different sides of the inner baffle.

[0008] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: the base is provided with a lower concave edge and a lower convex edge; the inner baffle includes an upper convex edge and an upper concave edge connected to each other.

[0009] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: a limiting ring is provided on the inner wall of the outer housing; a limiting groove is provided on the outer wall of the inner housing; the limiting ring and the limiting groove are slidably connected.

[0010] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: a conduit is provided on the inner baffle, and a rotating sleeve is provided on the top cover; the conduit and the rotating sleeve are rotatably connected.

[0011] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: the second rotating member further includes an airbag provided on the inner baffle, a delivery pipe is provided on the airbag, and the delivery pipe is communicated with the conduit.

[0012] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: the top cover is provided with limiting arc plates arranged symmetrically, and a retaining edge is provided on the limiting arc plates.

[0013] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: a thread groove is provided on the outer wall of the conduit; a nut is movably connected to one end of the rotating sleeve; the nut is threadedly connected with the thread groove; the retaining edge is slidably connected with the outer housing.

[0014] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: a lower turning handle is provided on the rotating sleeve; an upper turning handle is provided on the conduit, and an air pipe is provided at one end of the conduit.

[0015] As a preferred embodiment of the geographical survey sampling device for bridge construction of the present invention, the following is provided: the inner diameter of the inner wall of the limiting arc plate is equal to the outer diameter of the outer housing; the axes of the two symmetrically arranged limiting arc plates and the outer housing are located on the same straight line.

[0016] Advantages of the geographical survey sampling device for bridge construction of the present invention: During the insertion process of the present invention, the silt will not be extruded, which can improve the accuracy of the sample. When taking a sample for the first time, the silt in the accommodation channel is the silt sample directly inserted to the corresponding depth, and the silt sample on the other side is the silt sample after slight precipitation. While ensuring the accuracy of the sampled sample, it can also improve the diversity of sampling, which is convenient for the sampling personnel to make comparisons. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the overall structure of the geographical survey sampling device for bridge construction.

[0019] Figure 2 It is the first three-dimensional view of the insertion state of the geographical survey sampling device for bridge construction.

[0020] Figure 3 It is the second three-dimensional view of the insertion state of the geographical survey sampling device for bridge construction.

[0021] Figure 4 It is a schematic diagram of the structure of the first rotating member of the geographical survey sampling device for bridge construction.

[0022] Figure 5 It is the first three-dimensional view of the extraction state of the geographical survey sampling device for bridge construction.

[0023] Figure 6 It is the second three-dimensional view of the extraction state of the geographical survey sampling device for bridge construction.

[0024] Figure 7 It is a schematic diagram of the exploded structure of the geographical survey sampling device for bridge construction.

[0025] Figure 8 It is a sectional view of the geographical survey sampling device for bridge construction.

[0026] In the figure: 1. First rotating member; 11. Base; 111. Lower inlet; 112. Lower concave edge; 113. Lower convex edge; 12. Top cover; 121. Upper discharge outlet; 122. Limit arc piece; 123. Baffle edge; 13. Outer housing; 131. Discharge channel; 132. Limit ring; 14. Rotating sleeve; 141. Lower turning handle; 142. Nut; 2. Second rotating member; 21. Inner baffle; 211. Upper convex edge; 212. Upper concave edge; 22. Inner housing; 221. Limit groove; 23. Accommodating channel; 24. Isolation arc piece; 25. Duct; 251. Air pipe; 252. Upper turning handle; 253. Thread groove; 254. Rotating ring; 26. Airbag; 261. Delivery pipe. Detailed implementation mode

[0027] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation mode of the present invention will be given in conjunction with the accompanying drawings of the specification.

[0028] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0029] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation mode of the present invention. The "in one embodiment" that appears in different places in this specification does not all refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0030] Embodiment 1, referring to Figures 1 to 8 , which is the first embodiment of the present invention. This embodiment provides a geographical survey sampling device for bridge construction, including a first rotating member 1, which includes a base 11 and a top cover 12, and an outer housing 13 provided between the base 11 and the top cover 12;

[0031] Among them, a lower inlet 111 is provided on the base 11, an upper discharge outlet 121 is provided on the top cover 12, and a discharge channel 131 is provided between the outer housing 13 and the top cover 12;

[0032] It should be noted that the height of the outer housing 13 is less than the distance between the top cover 12 and the base 11. Therefore, the separation gap between the outer housing 13 and the top cover 12 forms the discharge channel 131; the top of the base 11 and the bottom of the outer housing 13 are fixedly connected.

[0033] The second rotating member 2, which includes an inner retaining piece 21 and an inner housing 22 provided on the inner retaining piece 21. A receiving channel 23 is formed between the inner retaining piece 21 and the inner housing 22. It also includes an isolation arc piece 24 provided on the inner retaining piece 21;

[0034] It should be noted that the outer wall diameter of the isolation arc piece 24 matches the outer wall diameter of the outer housing 13, while the length of the inner retaining piece 21 is greater than the length of the inner housing 22. The outer wall diameter of the inner housing 22 matches the inner wall diameter of the outer housing 13, and the inner housing 22 and the outer housing 13 are rotatably connected.

[0035] Preferably, referring to Figure 7 and Figure 8 , both the inner housing 22 and the outer housing 13 are hollow cylindrical structures with a part cut off, and the cut-off part is close to the axis of the inner housing 22 and the outer housing 13. Therefore, both the inner housing 22 and the outer housing 13 are hollow cylindrical structures with more than half, so as to ensure that a stable socket joint can be formed between the inner housing 22 and the outer housing 13, and the inner housing 22 can rotate within the outer housing 13.

[0036] Furthermore, the lower inlet 111 and the upper discharge port 121 are provided on different sides of the inner retaining piece 21; the discharge channel 131 and the upper discharge port 121 are provided on different sides of the inner retaining piece 21; the isolation arc piece 24 and the receiving channel 23 are provided on different sides of the inner retaining piece 21.

[0037] Among them, the base 11 is provided with a lower concave edge 112 and a lower convex edge 113; the inner retaining piece 21 includes an upper convex edge 211 and an upper concave edge 212 that are connected. The lower concave edge 112 and the upper concave edge 212 match, and the lower convex edge 113 and the upper convex edge 211 match.

[0038] When the receiving channel 23 is aligned with the lower inlet 111 and the discharge channel 131, the sludge can enter the discharge channel 131 through the lower inlet 111. The relative rotation of the first rotating member 1 and the second rotating member 2 can cause the isolation arc piece 24 to block the discharge channel 131.

[0039] During use, referring to Figure 2 and Figure 3, This is the state diagram when the sampling device is inserted. The lower inlet 111 and the discharge channel 131 are on the same side. The accommodating channel 23 connects the lower inlet 111 and the discharge channel 131. In this state, when the sampling device is inserted into the silt, the silt can enter the accommodating channel 23 through the lower inlet 111 and then be discharged from the discharge channel 131. Among them, the base 11 is a conical structure, which is convenient for the base 11 to push aside the silt and insert. During the insertion process, since the silt can flow in the accommodating channel 23, and except for the part of the base 11 where the lower inlet 111 is not opened, which will cause resistance during insertion, the silt in other parts has good fluidity and will not be overly obstructed. Therefore, the resistance during insertion can be effectively reduced, saving physical effort during insertion. After the insertion resistance is reduced, the silt can flow more easily inside the accommodating channel 23. Therefore, the silt in the accommodating channel 23 can be the original silt at the insertion depth, effectively reducing the disturbance to the silt during insertion and improving the accuracy of the sample.

[0040] When inserted to the sampling depth, at this time, preparation is made to sample the silt. Wait for a moment to allow the silt on the side of the inner baffle 21 away from the inner housing 22 to settle and reset. Since when the sampling device is inserted, the silt on this side is only slightly pushed by the base 11, and the side of the inner baffle 21 away from the inner housing 22 is in a hollow state, the silt can reset and fill the side of the inner baffle 21 away from the inner housing 22 relatively quickly, reducing the waiting time for the silt to settle. Subsequently, by rotating the first rotating member 1 or the second rotating member 2, relative rotation is generated between the outer housing 13 and the inner housing 22. Preferably, rotate the first rotating member 1 because when the first rotating member 1 rotates, the outer housing 13 makes a circular motion to perform a circular cutting on the surrounding silt. When the second rotating member 2 rotates, the rotation of the inner baffle 21 will push the silt on the side of the inner baffle 21 away from the inner housing 22, thus causing disturbance. It is difficult to avoid the rotation of the second rotating member 2 when the first rotating member 1 rotates. Due to the settings of the lower concave edge 112, the upper concave edge 212, the lower convex edge 113, and the upper convex edge 211, when the inner baffle 21 rotates, it can assist in pushing the silt on the side of the inner baffle 21 away from the inner housing 22 through the upper concave edge 212, and assist in pushing the silt in the accommodating channel 23 through the upper convex edge 211, so as to minimize the impact of the disturbance on the sampling accuracy and improve the accuracy of the sample.

[0041] When a relative rotation of 180 degrees occurs between the first rotating member 1 and the second rotating member 2, refer to Figure 5 and Figure 6, at this time, the base 11 blocks the bottom of the accommodating channel 23, the outer housing 13 blocks and seals the opening of the inner housing 22, and the isolation arc piece 24 seals the discharge channel 131. Therefore, at this time, both sides of the inner baffle 21 of the sampling device are filled with the silt to be sampled.

[0042] After sampling is completed, the sampling device is pulled out from the silt. Since the base 11 seals the bottom end of the accommodating channel 23, the silt in the accommodating channel 23 can be directly lifted. The top cover 12, in cooperation with the isolation arc piece 24, the outer housing 13 and the inner baffle 21, forms a closed space on the other side. Therefore, the silt on the side of the inner baffle 21 away from the inner housing 22 can be extracted by adsorption. The adsorption principle is the same as that of the piston sampling device, so as to realize the sampling of two samples at the same time.

[0043] Preferably, the base 11, the top cover 12, the outer housing 13, the inner housing 22, and the isolation arc piece 24 are all made of hard rubber material, which can improve the sealing performance between the structures.

[0044] Among them, a limiting ring 132 is provided on the inner wall of the outer housing 13; a limiting groove 221 is provided on the outer wall of the inner housing 22; the limiting ring 132 and the limiting groove 221 are slidably connected. The limiting ring 132 is made of rubber material. The arrangement of the limiting ring 132 and the limiting groove 221 can increase the stability when the outer housing 13 and the inner housing 22 rotate.

[0045] Compared with the sampling device of the negative pressure pump suction type, the present invention has less disturbance. Compared with the piston sampling device, the present invention will not cause extrusion to the silt during the insertion process, so as to improve the accuracy of the sample. When sampling once, the silt in the accommodating channel 23 is the silt sample directly inserted into the corresponding depth, and the silt sample on the other side is the silt sample after slight precipitation, which can improve the diversity of sampling while ensuring the accuracy of the sampling sample.

[0046] Example 2, referring to Figures 1 to 8 , which is the second embodiment of the present invention. Different from the previous embodiment, a conduit 25 is provided on the inner baffle 21, and a rotating sleeve 14 is provided on the top cover 12;

[0047] The conduit 25 is rotatably connected to the rotating sleeve 14. The conduit 25 is fixedly connected to the inner baffle 21. The top cover 12 is fixedly connected to the rotating sleeve 14. The rotating sleeve 14 is sleeved outside the conduit 25. By rotating the conduit 25 or the rotating sleeve 14, the second rotating member 2 or the first rotating member 1 can be controlled to rotate.

[0048] Specifically, the second rotating member 2 further includes an airbag 26 provided on the inner baffle 21. A delivery pipe 261 is provided on the airbag 26. The delivery pipe 261 is communicated with the conduit 25.

[0049] The remaining structures are the same as those in Embodiment 1.

[0050] During use, due to the increase in the depth of insertion into the silt, the resistance during the insertion of the sampling device also increases. During the insertion of the sampling device, the air supply device can continuously inflate and deflate the conduit 25, causing the airbag 26 to expand and contract intermittently, so that the surrounding silt can be pushed away, facilitating the sampling device to be inserted to a deeper depth.

[0051] After reaching the sampling depth, the inflated airbag 26 is contracted. After the airbag 26 is contracted, the surrounding silt can quickly flow into the side of the inner baffle 21 away from the inner housing 22 to improve the silt reset efficiency. Then, by rotating the first rotating member 1, the side of the inner baffle 21 away from the inner housing 22 is closed by the outer housing 13.

[0052] After taking out the sampling device, there are two ways to take out the silt in the sampling device. One is to evenly mix the silt samples on both sides of the inner baffle 21 as the final sample. The other is to separately take out the silt samples on both sides of the inner baffle 21. For the first method, when the silt samples on both sides need to be mixed, the operator can directly rotate the first rotating member 1 or the second rotating member 2 to make the sampling device return to Figure 2 and Figure 3 the state. At this time, the bottom end of the accommodation channel 23 is unobstructed and is aligned with the lower inlet 111, and the upper part of the accommodation channel 23 is connected to the discharge channel 131. The silt can flow down naturally under the action of gravity, and the side of the inner baffle 21 away from the inner housing 22 is exposed, and the silt can be shaken off directly; referring to Figure 5 and Figure 6 , for the second method of separately taking out the silt samples on both sides of the inner baffle 21, the airbag 26 can be inflated first to extrude the silt on the side of the inner baffle 21 away from the inner housing 22 from the lower inlet 111, and then the silt in the accommodation channel 23 can be poured out through the upper discharge port 121.

[0053] Embodiment 3, referring to Figures 1 to 8 , is the third embodiment of the present invention. Different from the previous embodiment, the top cover 12 is provided with symmetrically arranged limiting arc pieces 122, and the limiting arc pieces 122 are provided with edges 123. Both the limiting arc pieces 122 and the edges 123 are made of rubber.

[0054] The inner wall diameter of the limiting arc piece 122 is equal to the outer wall diameter of the outer housing 13; the two symmetrically arranged limiting arc pieces 122 and the axis of the outer housing 13 are on the same straight line, and the inner wall of the limiting arc piece 122 is slidably connected to the outer wall of the outer housing 13.

[0055] Since the edge 123 abuts against the two side edges of the outer housing 13, and the two limiting arc pieces 122 clamp the outer housing 13 so that the center point of the limiting arc piece 122 and the axis point of the outer housing 13 are on the same straight line, when the limiting arc piece 122 rotates, it can push the outer housing 13 to rotate synchronously.

[0056] It should be noted that a rotating ring 254 is provided on the outer wall of the conduit 25. The conduit 25 is rotatably connected to the base 11 through the rotating ring 254, and the conduit 25 penetrates through the base 11.

[0057] A threaded groove 253 is provided on the outer wall of the conduit 25; one end of the rotating sleeve 14 is movably connected with a nut 142; the nut 142 is threadedly connected with the threaded groove 253;

[0058] The edge 123 is slidably connected to the outer housing 13.

[0059] A lower turning handle 141 is provided on the rotating sleeve 14; an upper turning handle 252 is provided on the conduit 25. One end of the conduit 25 is provided with an air pipe 251, and the air pipe 251 is connected to a gas supply device to realize inflation and deflation of the airbag 26.

[0060] All the other structures are the same as those in Embodiment 2.

[0061] During use, refer to Figures 1 to 3 , this is the state diagram when the sampling device is inserted into the silt. At this time, the nut 142 can be in a state where it does not abut against the end of the rotating sleeve 14, and a 180-degree angle is formed between the upper turning handle 252 and the lower turning handle 141, so as to facilitate the operator to rotate the first rotating member 1 or the second rotating member 2 subsequently. At the same time, the 180-degree angle formed between the upper turning handle 252 and the lower turning handle 141 can facilitate the operator to press the upper turning handle 252 and the lower turning handle 141, so that the sampling device is inserted into the silt.

[0062] When the isolation of the silt on both sides of the inner baffle 21 is completed by rotating the first rotating member 1 and the second rotating member 2, refer to Figure 5 and Figure 6 , at this time, by rotating the nut 142, pressure is applied to the rotating sleeve 14 through the nut 142, so that the top cover 12 presses the isolation arc piece 24, and the bottom end of the isolation arc piece 24 is closely attached to the top end of the outer housing 13, so as to improve the sealing performance between the structures and facilitate the removal of the silt on the side of the inner baffle 21 away from the inner housing 22 from the water.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A geographical survey sampling device for bridge construction, characterized in that: including, a first rotating member (1), which includes a base (11) and a top cover (12), and an outer housing (13) provided between the base (11) and the top cover (12); a lower inlet (111) is provided on the base (11), an upper discharge port (121) is provided on the top cover (12), and a discharge channel (131) is provided between the outer housing (13) and the top cover (12); a second rotating member (2), which includes an inner baffle (21), and an inner housing (22) provided on the inner baffle (21), a receiving channel (23) is formed between the inner baffle (21) and the inner housing (22), and an isolation arc plate (24) is also provided on the inner baffle (21); when the receiving channel (23) is aligned with the lower inlet (111) and the discharge channel (131), silt can enter the discharge channel (131) through the lower inlet (111), and relative rotation of the first rotating member (1) and the second rotating member (2) can cause the isolation arc plate (24) to block the discharge channel (131).

2. The bridge construction geographical survey sampling device according to claim 1, characterized in that: the lower inlet (111) and the upper discharge port (121) are provided on different sides of the inner baffle (21); the discharge channel (131) and the upper discharge port (121) are provided on different sides of the inner baffle (21); the isolation arc plate (24) and the receiving channel (23) are provided on different sides of the inner baffle (21).

3. The bridge construction geographical survey sampling device according to claim 2, characterized in that: a lower concave edge (112) and a lower convex edge (113) are provided on the base (11); the inner baffle (21) includes a connected upper convex edge (211) and an upper concave edge (212).

4. The bridge construction geographical mapping sampling device according to claim 3, characterized in that: a limiting ring (132) is provided on the inner wall of the outer housing (13); a limiting groove (221) is provided on the outer wall of the inner housing (22); the limiting ring (132) and the limiting groove (221) are slidably connected.

5. The bridge construction geographical survey sampling device according to any one of claims 1 to 4, characterized in that: a conduit (25) is provided on the inner baffle (21), and a rotating sleeve (14) is provided on the top cover (12); the conduit (25) and the rotating sleeve (14) are rotatably connected.

6. The bridge construction geographical mapping sampling device according to claim 5, wherein: the second rotating member (2) further includes an airbag (26) provided on the inner baffle (21), a delivery pipe (261) is provided on the airbag (26), and the delivery pipe (261) is communicated with the conduit (25).

7. The bridge construction geographical survey sampling device according to claim 6, characterized in that: symmetrically arranged limiting arc plates (122) are provided on the top cover (12), and a retaining edge (123) is provided on the limiting arc plates (122).

8. The bridge construction geographical survey sampling device according to claim 7, characterized in that: a threaded groove (253) is provided on the outer wall of the conduit (25); a nut (142) is movably connected to one end of the rotating sleeve (14); the nut (142) and the threaded groove (253) are threadedly connected; the retaining edge (123) and the outer housing (13) are slidably connected.

9. The bridge construction geographical survey sampling device according to claim 8, characterized in that: a lower turning handle (141) is provided on the rotating sleeve (14); an upper turning handle (252) is provided on the conduit (25), and an air pipe (251) is provided at one end of the conduit (25).

10. The bridge construction geographical survey sampling device according to claim 8, characterized in that: the inner wall diameter of the limiting arc plate (122) is equal to the outer wall diameter of the outer housing (13); the two symmetrically arranged limiting arc plates (122) and the axis of the outer housing (13) are on the same straight line.

Images