Clamping device

Abstract

The utility model provides a clamping device which comprises a main body and a locking piece. The main body comprises a mounting part and a clamping part which are coaxially arranged, the clamping part comprises at least four clamping blocks which are arranged at intervals in the circumferential direction, the clamping blocks extend in the axis direction of the main body and are provided with arc-shaped inner walls, the arc-shaped inner walls of the at least four clamping blocks equally divide the same circumference, and a circular clamping hole is formed among the at least four clamping blocks. And the locking piece is provided with variable-diameter inner holes which are rotationally matched with the outer wall surfaces of the at least four clamping blocks, and the variable-diameter inner holes are suitable for rotating and pressing the at least four clamping blocks to move in the direction close to the axis at the same time. The at least four clamping blocks can press a workpiece in the axial direction at the same time, so that the concentricity meets the requirement, rapid clamping and positioning are achieved, repeated proofreading is not needed, the machining efficiency is improved, and meanwhile the yield is also improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical processing, in particular to a clamping device. Background Art

[0002] Figure 1 A target base locating pin is shown. The target base locating pin includes two opposite parts, which are defined as a first part and a second part, the first part has a first outer diameter, and the second part has a second outer diameter, for example, the first outer diameter and the second outer diameter can be 15 mm and 10 mm respectively. The first part includes a first inner hole, and the second part includes a second inner hole. The first inner hole has a first inner diameter, and the second inner hole has a second inner diameter, for example, the first inner diameter and the second inner diameter can be 10 mm and 8 mm respectively, wherein the first inner diameter and the first outer diameter need to maintain strict concentricity, for example, the concentricity is 0.01 mm or even less. The second inner diameter and the second outer diameter also need to maintain strict concentricity, for example, the concentricity is 0.01 mm or even less.

[0003] This target seat positioning pin requires that the concentricity of both ends of the pin be consistent and within 0.01mm to meet the requirements of the assembly interface. In the existing processing technology, the first part and the second part need to be processed separately, and the processing of the first part and the second part cannot be completed during the same clamping. In the prior art, for such parts that have concentricity indicators at both ends and require high consistency of indicators and cannot be clamped and processed in one time, the conventional method is to use an ordinary three-jaw chuck for two clampings, that is, first clamping at the first part for the first time to process the second part, and then clamping at the second part for the second time to process the first part. During the second clamping, multiple trial assembly tests are required until the circular runout value after clamping is verified to be within 0.01mm, and it can only be processed when it is confirmed that the concentricity indicator requirements are met. The clamping method of the conventional clamping device is inefficient and requires repeated proofreading. It is not easy to ensure the concentricity requirements of the first part and the second part, which easily produces unqualified products and leads to poor pass rate. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the defects that the clamping method of the clamping device in the prior art is low in efficiency, requires repeated proofreading, and is not easy to ensure the concentricity requirements of the first part and the second part, easily produces defective products, and leads to a poor pass rate, thereby providing a clamping device.

[0005] In order to solve the above problems, the utility model provides a clamping device, comprising:

[0006] The main body comprises a coaxially arranged mounting portion and a clamping portion, wherein the clamping portion comprises at least four clamping blocks spaced apart in a circumferential direction, wherein the clamping blocks extend along the axis direction of the main body and have arc-shaped inner walls, wherein the arc-shaped inner walls of at least four of the clamping blocks equally divide the same circumference, and a circular clamping hole is formed between the at least four of the clamping blocks;

[0007] The locking member has a variable diameter inner hole rotatably matched with the outer wall surface of at least four clamping blocks, and the variable diameter inner hole is suitable for rotating and pressing at least four clamping blocks and moving toward the direction close to the axis at the same time.

[0008] Optionally, the outer wall of the clamping block includes an extension portion and a reducing portion, the extension portion is located between the reducing portion and the mounting portion, the extension portion is parallel to the axial direction, and the reducing portion extends obliquely from the extension portion toward the direction close to the clamping hole, and at least four of the reducing portions form a conical outer edge concentric with the clamping hole; the reducing inner hole includes a third inner hole that is press-fitted with the reducing portion, and a fourth inner hole that is press-fitted with the extension portion, and the third inner hole is a conical inner hole that is adapted to the shape of the conical outer edge.

[0009] Optionally, the angle between the tapered outer edge and the axial direction ranges from 10° to 30°.

[0010] Optionally, a fifth inner hole is provided between the third inner hole and the fourth inner hole, and an inner diameter of the fifth inner hole is larger than an inner diameter of the third inner hole and larger than an inner diameter of the fourth inner hole.

[0011] Optionally, the outer wall surface of the clamping block is provided with an external thread, and the variable diameter inner hole is provided with an internal thread.

[0012] Optionally, there are through slots between adjacent clamping blocks.

[0013] Optionally, a through hole is provided at an edge of the through slot close to the mounting portion.

[0014] Optionally, the clamping hole includes a first inner hole and a second inner hole, the first inner hole is formed at the end of the clamping block away from the mounting portion, the second inner hole extends from the through hole in a direction away from the mounting portion to connect with the first inner hole, and the diameter of the first inner hole is larger than the diameter of the second inner hole.

[0015] Optionally, an annular flange is coaxially arranged between the mounting portion and the clamping portion.

[0016] Optionally, an annular groove is formed on the clamping portion near the annular flange.

[0017] The utility model has the following advantages:

[0018] The clamping device provided by the utility model comprises a main body and a locking member. The main body comprises a mounting portion and a clamping portion arranged coaxially, the clamping portion comprises at least four clamping blocks arranged at intervals along the circumferential direction, the clamping blocks extend along the axial direction of the main body and have an arc-shaped inner wall, the arc-shaped inner walls of at least four clamping blocks equally divide the same circumference, and a circular clamping hole is formed between at least four clamping blocks. The locking member has a variable diameter inner hole that is rotatably matched with the outer wall surface of at least four clamping blocks, and the variable diameter inner hole is suitable for rotating and pressing at least four clamping blocks while moving in a direction close to the axis.

[0019] The mounting portion can be clamped by a chuck of a processing machine tool. Since the mounting portion and the clamping portion are coaxially arranged, the chuck can drive the mounting portion and the clamping portion to rotate around the same axis. The first part of the target seat locating pin shaft can be clamped and processed by conventional processing methods, and then the part is extended into the circular clamping hole between at least four clamping blocks, and then the reducing inner hole of the locking piece is used to sleeve on the at least four clamping blocks, and the reducing inner hole is used to rotate and press the at least four clamping blocks and move them in the direction close to the axis at the same time. Since the arcuate inner walls of the at least four clamping blocks divide the same circumference equally, the arcuate inner walls of the at least four clamping blocks can fit with the outer wall of the first part and press the first part with the same force, so that the axis of the first part is aligned with the axis of the clamping hole of the clamping part, and then the axis of the first part of the target seat locating pin shaft is aligned with the axis of the mounting part, so that the concentricity of the first part can be ensured to meet the processing requirements, and then the concentricity of the second part to be processed is kept consistent with the first part, so as to facilitate the processing of the second part, realize rapid clamping and positioning, and do not need repeated proofreading, thereby improving processing efficiency and also improving the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the structure of the target seat positioning pin is shown;

[0022] Figure 2 A schematic structural diagram of a clamping device is shown;

[0023] Figure 3 A schematic diagram of the structure of the main body is shown;

[0024] Figure 4 A schematic cross-sectional structure diagram of the main body is shown;

[0025] Figure 5 A schematic cross-sectional structure diagram of a locking member is shown;

[0026] Figure 6 A schematic diagram of the structure of the locking member is shown;

[0027] Figure 7 The schematic diagram of the structure of the clamping device for clamping the target seat positioning pin is shown.

[0028] Description of reference numerals:

[0029] 100, target seat locating pin; 110, transition section; 120, first part; 130, second part; 122, first axial hole; 132, second axial hole; 200, clamping device; 210, main body; 212, mounting portion; 213, clamping portion; 214, clamping block; 216, annular flange; 218, extension portion; 22, clamping hole; 220, reducing portion; 222, first inner hole; 224, second inner hole; 226, through hole; 228, through groove; 240, locking member; 242, fourth inner hole; 244, third inner hole; 246, fifth inner hole; 248, depression. DETAILED DESCRIPTION

[0030] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] like Figure 1 The target seat positioning pin 100 shown includes a first portion 120 and a second portion 130, and a transition section 110 located between the first portion 120 and the second portion 130, and the transition section 110 is used to limit the size of the first portion 120 and the second portion 130. The first portion 120 has a first outer diameter D1, and the second portion 130 has a second outer diameter D2. The first outer diameter D1 can be greater than the second outer diameter D2, for example, the first outer diameter D1 and the second outer diameter D2 are 15 mm and 10 mm respectively. The first portion 120 includes a first axial hole 122, and the second portion 130 includes a second axial hole 132. The first axial hole 122 has a first inner diameter d1, and the second axial hole 132 has a second inner diameter d2, for example, the first inner diameter d1 and the second inner diameter d2 can be 10 mm and 8 mm respectively. Strict concentricity needs to be maintained between the first inner diameter d1 and the first outer diameter D1, for example, the concentricity is 0.01 mm or 0.005 mm or even smaller. The second inner diameter d2 and the second outer diameter D2 also need to maintain strict concentricity, for example, the concentricity is 0.01 mm or 0.005 mm or even smaller.

[0035] A conventional three-jaw chuck performs two clamping operations, i.e., first clamping is performed at the first part 120 to process the second part 130, and then clamping is performed at the second part 130 to process the first part 120. During the second clamping, multiple test runs are required until the circular runout value after clamping is verified to be within 0.01 mm. Processing can only be performed when it is confirmed that the concentricity index requirements are met. This processing method is not only inefficient, but also not conducive to meeting the concentricity requirements of the first part 120 and the second part 130, and is prone to produce unqualified products, resulting in a poor pass rate.

[0036] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, in order to solve the above problems, the utility model provides a clamping device, and the clamping device 200 includes a main body 210 and a locking member 240.

[0037] The main body 210 includes a coaxially arranged mounting portion 212 and a clamping portion 213. The mounting portion 212 may be a cylindrical structure, and the clamping portion 213 may be a cylindrical structure. The coaxial arrangement of the mounting portion 212 and the clamping portion 213 means that the two can rotate around the same rotation axis. The clamping portion 213 includes at least four clamping blocks 214 arranged at intervals along the circumferential direction. The clamping blocks 214 extend along the axial direction of the main body 210 and have an arc-shaped inner wall. The arc-shaped inner walls of at least four clamping blocks 214 divide the same circumference equally, and a circular clamping hole 22 is formed between at least four clamping blocks 214. The circular shape of the clamping hole 22 is conducive to the first part 120 or the second part 130 of the positioning pin shaft of the target seat. The locking member 240 has a variable diameter inner hole that is rotatably matched with the outer wall surface of at least four clamping blocks 214. The variable diameter inner hole is suitable for rotating and pressing at least four clamping blocks 214 while moving in the direction close to the axis. The inner diameter of the end of the variable diameter inner hole close to the clamping block 214 is larger than the inner diameter of the end away from the clamping block 214, so that the variable diameter inner hole can gradually squeeze the clamping block 214 in the axial direction, thereby ensuring that the axis of the first part 120 or the second part 130 is aligned with the axis of the clamping part 213.

[0038] like Figure 7 As shown, the mounting portion 212 can be clamped by the chuck of the processing machine tool. Since the mounting portion 212 and the clamping portion 213 are coaxially arranged, the chuck can drive the mounting portion 212 and the clamping portion 213 to rotate around the same axis. The first portion 120 of the target seat positioning pin can be clamped and processed by conventional processing methods, and then the first portion 120 is extended into the circular clamping hole 22 between at least four clamping blocks 214, and then the reducing inner hole of the locking member 240 is used to sleeve on the at least four clamping blocks 214, and the reducing inner hole is used to rotate and press the at least four clamping blocks 214 and move them in the direction close to the axis at the same time. Since the arcuate inner walls of the at least four clamping blocks 214 divide the same circumference equally, the arcuate inner walls of the at least four clamping blocks 214 can fit with the outer wall of the first portion 120. , and press the first part 120 with the same force, so that the axis of the first part 120 is aligned with the axis of the clamping hole 22 of the clamping part 213, and then the axis of the first part 120 of the target seat positioning pin is aligned with the axis of the mounting part 212, so that the concentricity of the first part 120 can be guaranteed to meet the processing requirements, and then the concentricity of the second part 140 to be processed is consistent with the first part 120, so as to facilitate the processing of the second part 140, realize rapid clamping and positioning, and do not need repeated proofreading, thereby improving the processing efficiency and also improving the yield rate.

[0039] The number of clamping blocks 214 can be determined according to actual conditions, for example Figure 2As shown, the clamping portion 213 has eight clamping blocks 214, each clamping block 214 has an arc-shaped inner wall and an outer wall. The outer walls of the eight clamping blocks 214 divide the same circumference equally. The cross-sectional shape of the clamping block 214 is fan-shaped, and the variable diameter inner hole is a circular hole. This makes it easy for the variable diameter inner hole to gradually press each clamping block 214 to move toward the direction close to the axis, so that the arc-shaped inner walls of the eight clamping blocks 214 fit the outer wall of the first part 120 and keep the axis of the first part 120 almost coincident with the axis of the clamping hole 22.

[0040] like Figure 3 and Figure 4 As shown, in this embodiment, the outer wall of the clamping block 214 includes an extension portion 218 and a diameter reducing portion 220, the diameter reducing portion 220 is located at the end of the clamping block 214, the extension portion 218 is located between the diameter reducing portion 220 and the mounting portion 212, the extension direction of the extension portion 218 is parallel to the axial direction, the diameter reducing portion 220 extends obliquely from the extension portion 218 toward the direction close to the clamping hole 22, and at least four diameter reducing portions 220 form a conical outer edge concentric with the clamping hole 22. The diameter reducing inner hole includes a third inner hole 244 that is pressed and matched with the diameter reducing portion 220, and a fourth inner hole 242 that is pressed and matched with the extension portion 218, the third inner hole 244 is a conical inner hole that matches the shape of the conical outer edge, and the inclination angle between the conical inner hole and the axis is the same as the inclination angle between the conical outer edge and the axis. After the first part 120 is installed in the clamping hole 22, the locking piece 240 can be gradually rotated and installed on the clamping block 214 through the reducing inner hole. Specifically, during the installation process, the fourth inner hole 242 is rotated and contacted with the extension part 218. When the inner wall of the third inner hole 244 is in contact with the reducing part 220, the inner wall of the third inner hole 244 gradually applies pressure to the reducing part 220. At the same time, the arc-shaped inner wall of the clamping block 214 gradually applies pressure to the first part 120 to align the axis of the first part 120 with the axis of the clamping hole 22, so that the concentricity of the first part 120 meets the clamping requirements.

[0041] like Figure 3 and Figure 4 As shown, in this embodiment, the axial length L2 of the fourth inner hole 242 is greater than the axial length L1 of the reducing portion 220, and the end diameter of the tapered outer edge is greater than the minimum diameter of the fourth inner hole 242. The axial length refers to the length dimension in the direction of the rotation axis of the main body 210. The side of the fourth inner hole 242 away from the tapered outer edge has the minimum diameter, and the side close to the tapered outer edge has the maximum diameter. This arrangement can ensure that the end of the fourth inner hole 242 away from the tapered outer edge can be squeezed against the tapered outer edge with a narrower wall when gradually approaching the end of the tapered outer edge, thereby ensuring that the clamping block 214 can press the first part 120.

[0042] like Figure 4 and Figure 5 As shown, the angle between the tapered outer edge and the axial direction ranges from 10° to 30°. For example, the angle can be 10°, 12°, 14°, 16°, 18°, 20°, 22°, 24°, 26°, 28° or 30°. Correspondingly, the angle between the tapered inner hole and the tapered outer edge is the same. Such an arrangement can ensure that the tapered inner hole can slowly pressurize the tapered outer edge when rotating. At the same time, the clamping block 214 can also slowly pressurize the first part 120. The pressurization can be stopped after at least four clamping blocks 214 can firmly clamp the first part 120 to avoid excessive pressure causing wear of the outer wall of the first part 120 or deformation of the first part 120.

[0043] like Figure 5 As shown, in the present embodiment, a fifth inner hole 246 is arranged between the third inner hole 244 and the fourth inner hole 242. The inner diameter of the fifth inner hole 246 is larger than the inner diameter of the third inner hole 244 and larger than the inner diameter of the fourth inner hole 242. The wall surface of the fifth inner hole 246 does not contact the clamping block 214, so that a good pressure transition can be formed between the third inner hole 244 and the fourth inner hole 242, thereby reducing the pressure on the variable diameter inner hole and avoiding deformation of the variable diameter inner hole.

[0044] like Figure 4 and Figure 5 As shown, the outer wall surface of the clamping block 214 is provided with an external thread T1, and the reducing inner hole is provided with an internal thread T2. Specifically, the external thread T1 is provided on the extension portion 218, and the internal thread T2 is provided on the inner wall of the fourth inner hole 242. The external thread T1 and the internal thread T2 are threadedly matched to ensure that the locking member 240 moves along the axial direction toward the mounting portion 212. The reducing portion 220 is a smooth surface, and the wall surface of the third inner hole 244 is a smooth surface. While ensuring stable pressurization, it can also reduce the wear caused by the rotational contact between the two.

[0045] like Figure 3 and Figure 4 As shown, there are through slots 228 between adjacent clamping blocks 214, and the through slots 228 can provide a certain displacement space for the clamping blocks 214. Since the cross-sectional shape of the clamping blocks 214 is fan-shaped, when the clamping blocks 214 are displaced in the axial direction, the displacement space can avoid the movement interference of the arc-shaped outer wall of the clamping blocks 214. The number of the through slots 228 is the same as the number of the clamping blocks 214.

[0046] like Figure 3 and Figure 4As shown, a through hole 226 is provided at the edge of the through slot 228 near the mounting portion 212, and the number of the through holes 226 is the same as the number of the through slots 228. The through holes can reduce the root strength of the clamping block 214, which is beneficial to the end deformation of the clamping block 214, that is, it is convenient for the reducing portion 220 to move closer to the axis, so that the locking member 240 can easily clamp the first portion 120 through the clamping block 214.

[0047] like Figure 4 As shown, in this embodiment, the clamping hole 22 includes a first inner hole 222 and a second inner hole 224. The first inner hole 222 is formed at the end of the clamping block 214 away from the mounting portion 214, and the second inner hole 224 extends from the through hole 226 in a direction away from the mounting portion 212 to connect with the first inner hole 222. The diameter of the first inner hole 222 is larger than the diameter of the second inner hole 224. The aperture of the first inner hole 222 can match the first outer diameter D1 of the first portion 120 of the target seat positioning pin shaft, that is, the aperture of the first inner hole 222 can be slightly larger than The first outer diameter D1, for example, the aperture of the first inner hole 222 is 0.01mm, 0.005mm, 0.004mm, 0.003mm, 0.002mm or 0.001mm larger than the first outer diameter D1, so that the first part 120 can smoothly extend into the first inner hole 222, and the length dimension of the first inner hole 222 in the axial direction is greater than the length dimension of the first part 120 in the axial direction to ensure that the first part 120 can be fully extended into the first inner hole 222, so as to ensure the stability of processing.

[0048] The setting of the second inner hole 224 can ensure the strength of the clamping block 214 while reducing the root strength of the clamping block 214 to a certain extent, so that the locking piece 240 can easily drive the clamping block 214 to deform, so that the inner wall of the first inner hole 222 is pressed against the outer wall of the first part 120.

[0049] like Figure 2 and Figure 3 As shown, in this embodiment, an annular flange 216 is coaxially arranged between the mounting portion 212 and the clamping portion 213. The annular flange 216 is used to separate the mounting portion 212 and the clamping portion 213. When the chuck of the processing machine tool contacts the annular flange 216, it indicates that the clamping is in place.

[0050] like Figure 2 and Figure 3 As shown, in this embodiment, an annular groove 230 is provided at a position of the clamping portion 213 near the annular flange 216. The annular groove 230 can serve as a thread backing groove for the external thread T1 of the clamping block 214, and can also further reduce the root strength of the clamping block 214, so that the locking member 240 can easily apply force to lock the target seat positioning pin.

[0051] like Figure 6 As shown, in the present embodiment, the outer edge of the locking member 240 can be circular, and the outer surface of the locking member 240 has a plurality of recesses 248, and the plurality of recesses 248 are evenly distributed along the circumference of the outer surface of the locking member 240. For example, the number of the recesses 248 can be 2, 4, 6 or 8, etc. The recesses 248 can be used as force application holes for external tools, for example, they can be engaged with a wrench, so as to more conveniently apply force to the locking member 240 and drive the locking member 240 to rotate.

[0052] In this embodiment, the main body 210 and the locking member 240 may be made of a wear-resistant material, such as H62 copper alloy.

[0053] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A clamping device, characterized in that: include: The main body (210) comprises a coaxially arranged mounting portion (212) and a clamping portion (213), wherein the clamping portion (213) comprises at least four clamping blocks (214) arranged at intervals in a circumferential direction, wherein the clamping blocks (214) extend along the axial direction of the main body (210) and have an arc-shaped inner wall, wherein the arc-shaped inner walls of at least four of the clamping blocks (214) equally divide the same circumference, and a circular clamping hole (22) is formed between the at least four of the clamping blocks (214); The locking member has a variable diameter inner hole rotatably matched with the outer wall surface of at least four clamping blocks (214), and the variable diameter inner hole is suitable for rotating and pressing at least four clamping blocks (214) and moving in a direction close to the axis at the same time.

2. The clamping device according to claim 1, characterized in that: The outer wall of the clamping block (214) includes an extension portion (218) and a reducing portion (220), wherein the extension portion (218) is located between the reducing portion (220) and the mounting portion (212), and the extension portion (218) is parallel to the axial direction, and the reducing portion (220) extends obliquely from the extension portion (218) toward the direction close to the clamping hole (22), and at least four reducing portions (220) form a conical outer edge concentric with the clamping hole (22); the reducing inner hole includes a third inner hole (244) which is press-fitted with the reducing portion (220), and a fourth inner hole (242) which is press-fitted with the extension portion (218), and the third inner hole (244) is a conical inner hole adapted to the shape of the conical outer edge.

3. The clamping device according to claim 2, characterized in that: The angle between the tapered outer edge and the axis direction ranges from 10° to 30°.

4. The clamping device according to claim 2, characterized in that: A fifth inner hole (246) is provided between the third inner hole (244) and the fourth inner hole (242), and the inner diameter of the fifth inner hole (246) is larger than the inner diameter of the third inner hole (244) and larger than the inner diameter of the fourth inner hole (242).

5. The clamping device according to claim 1, characterized in that: The outer wall surface of the clamping block (214) is provided with an external thread, and the variable diameter inner hole is provided with an internal thread.

6. The clamping device according to claim 1, characterized in that: A through slot (228) is provided between adjacent clamping blocks (214).

7. The clamping device according to claim 6, characterized in that: A through hole (226) is provided at an edge of the through slot close to the mounting portion (212).

8. The clamping device according to claim 7, characterized in that: The clamping hole (22) includes a first inner hole (222) and a second inner hole (224), wherein the first inner hole (222) is formed at the end of the clamping block (214) away from the mounting portion (212), and the second inner hole (224) extends from the through hole (226) in a direction away from the mounting portion (212) to connect with the first inner hole (222), and the diameter of the first inner hole (222) is greater than the diameter of the second inner hole (224).

9. The clamping device according to any one of claims 1 to 7, characterized in that: An annular flange (216) is coaxially arranged between the mounting portion (212) and the clamping portion (213).

10. The clamping device according to claim 9, characterized in that: An annular groove (230) is formed on the clamping portion (213) at a position close to the annular flange (216).

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