Clamping device

Abstract

The utility model provides a clamping device, including: a main body, including a coaxially arranged mounting portion and a supporting portion, the supporting portion including at least four support blocks spaced apart in the circumferential direction, the support block having an arc-shaped outer wall extending along the axial direction of the main body, the cross section of the support block being fan-shaped, the arc-shaped outer walls of at least four support blocks being combined into a circular outer wall, and a variable diameter inner hole being provided between at least four support blocks, the diameter of the variable diameter inner hole gradually increasing from the side of the supporting portion close to the mounting portion to the end of the supporting portion. A fastener having an outer wall surface adapted to the shape of the variable diameter inner hole, suitable for extending into the variable diameter inner hole and simultaneously squeezing at least four support blocks to move in the axial direction away from the main body. Since at least four support blocks synchronously press the inner wall of the rotating thin-walled parts, it is ensured that the inner hole axis of the rotating thin-walled parts is highly consistent with the axis of the main body, and multiple proofreading is not required, which improves the processing efficiency and can also improve the production qualification rate.

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 long hood is shown, which is a typical rotating thin-walled part. The long hood includes a first cylindrical part, a second cylindrical part, and a transition part extending between the first cylindrical part and the second cylindrical part. Each of the first cylindrical part and the second cylindrical part is roughly cylindrical. The first cylindrical part has a first inner diameter and a first wall thickness. The second cylindrical part has a second inner diameter and a second wall thickness. The first inner diameter of the first cylindrical part is greater than the second inner diameter of the second cylindrical part. The first wall thickness may be equal to or not equal to the second wall thickness. The wall thickness of the transition part is equal to the first wall thickness of the first cylindrical part. In one example, the first inner diameter of the first cylindrical part is 49mm and the first wall thickness is 0.5mm, and the second inner diameter of the second cylindrical part is 29.2mm and the second wall thickness is 0.4mm. The wall thickness of the transition part is 0.5mm. Observed in a cross section, the transition part includes a 1 / 4 arc part, whose inner radius is 7mm and the outer radius is 7.5mm. The long hood can be made of TC4 titanium alloy, for example.

[0003] At present, the conventional method for processing this kind of rotating thin-walled parts is to first process the size of the inner hole, then process the mandrel that completely matches the size of the inner hole, plug the small end, and use the center clamp to process the outer diameter in place. Clamping this kind of rotating thin-walled parts by the mandrel and edge plugging requires repeated calibration of concentricity, and the processing efficiency is low. In addition, the above clamping method mainly fixes the parts by edge plugging, and the parts may become loose during the processing, resulting in a low production qualification rate. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the defects of the prior art in that the clamping is not firm, the processing efficiency is low and the production qualification rate is low when processing rotating thin-walled parts, thereby providing a clamping device.

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

[0006] A main body, comprising a coaxially arranged mounting portion and a supporting portion, wherein the supporting portion comprises at least four supporting blocks spaced apart in a circumferential direction, wherein the supporting block has an arc-shaped outer wall extending along the axial direction of the main body, wherein the cross section of the supporting block is fan-shaped, wherein the arc-shaped outer walls of at least four supporting blocks are combined into a circular outer wall, and wherein a variable diameter inner hole is provided between at least four supporting blocks, wherein the diameter of the variable diameter inner hole gradually increases from a side of the supporting portion close to the mounting portion to an end of the supporting portion;

[0007] The fastener has an outer wall surface matched with the shape of the variable diameter inner hole, and is suitable for extending into the variable diameter inner hole and simultaneously squeezing at least four of the support blocks and moving in a direction away from the axis of the main body.

[0008] Optionally, the variable diameter inner hole includes a first inner hole and a second inner hole, the first inner hole is formed in the mounting portion and is coaxial with the mounting portion, the inner wall of the support block extends obliquely from the first inner hole to the end of the support block, and the second inner hole whose inner diameter increases from the first inner hole to the end of the support block is formed between at least four of the support blocks; the fastener has a connecting portion and a tapered portion, the connecting portion is adapted to the inner diameter of the first inner hole, and the outer wall of the tapered portion is adapted to the shape of the second inner hole.

[0009] Optionally, the first inner hole has an internal thread, and the connecting portion has an external thread.

[0010] Optionally, the angle between the inner wall of the second inner hole and the axis of the main body ranges from 10° to 30°.

[0011] Optionally, there are through grooves between adjacent support blocks.

[0012] Optionally, a through hole is provided at an edge of the through slot close to the mounting portion.

[0013] Optionally, an end surface of the fastener facing away from the mounting portion has a recess.

[0014] Optionally, the recess is a hexagonal recess.

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

[0016] Optionally, an annular groove is formed on the support 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 fastener. The main body comprises a coaxially arranged mounting portion and a supporting portion, the supporting portion comprises at least four supporting blocks spaced apart in the circumferential direction, the supporting block has an arc-shaped outer wall extending along the axial direction of the main body, the cross section of the supporting block is fan-shaped, the arc-shaped outer walls of at least four supporting blocks are combined into a circular outer wall, and there is a variable diameter inner hole between at least four supporting blocks, the diameter of the variable diameter inner hole gradually increases from the side of the supporting portion close to the mounting portion to the end of the supporting portion. The fastener has an outer wall surface adapted to the shape of the variable diameter inner hole, suitable for extending into the variable diameter inner hole and simultaneously squeezing at least four supporting blocks and moving in the axial direction away from the main body.

[0019] The mounting part can be mounted on the chuck of the processing machine tool, and the chuck drives the mounting part and the supporting part to rotate along the same axis when rotating. After the inner hole of the rotating thin-walled part is processed, the rotating thin-walled part can be mounted on the supporting part through the inner hole, and the arc-shaped outer walls of at least four supporting blocks fit with the inner wall of the rotating thin-walled part. Then, the fastener can be inserted into the variable diameter inner hole of the supporting block. Since the diameter of the variable diameter inner hole gradually increases from the side of the supporting part close to the mounting part to the end of the supporting part, the fastener is adapted to the shape of the variable diameter inner hole. During the process of the fastener being inserted, the outer wall of the fastener will gradually squeeze the inner wall of the supporting block. The inner walls of at least four supporting blocks are squeezed at the same time and move in the direction away from the axis. The arc-shaped outer walls of at least four supporting blocks gradually press the inner wall of the rotating thin-walled part, thereby locking the rotating thin-walled part. Since at least four support blocks simultaneously press the inner wall of the rotating thin-walled parts, it can ensure that the inner hole axis of the rotating thin-walled parts is highly consistent with the axis of the mounting part and the support part, solving the concentricity problem of the rotating thin-walled parts, and no repeated calibration is required, which improves the clamping efficiency and processing efficiency. Since the arc-shaped outer wall of the support block is attached to and locked with the inner wall of the rotating thin-walled parts, the contact area and effective locking pressure are increased, which overcomes the problem of loosening of the rotating thin-walled parts during processing and improves the production qualification rate.

[0020] In addition, the above clamping device can be applied to short-axis or long-axis rotating thin-walled parts. The support block can fully support most of the inner walls of the rotating thin-walled parts, and the wall surface of the rotating thin-walled parts is not easily deformed during the processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 It is a schematic diagram of the cross-sectional structure of a rotating thin-walled part;

[0023] Figure 2 Schematic diagram of the structure of the clamping device in this embodiment;

[0024] Figure 3 Schematic diagram of the structure of the main body in this embodiment;

[0025] Figure 4 Schematic diagram of the cross-sectional structure of the main body in this embodiment;

[0026] Figure 5is a schematic diagram of the structure of the fastener in this embodiment;

[0027] Figure 6 is a schematic cross-sectional structure diagram of the fastener in this embodiment;

[0028] Figure 7 This is a schematic cross-sectional structure diagram of the clamping device in this embodiment for locking and rotating thin-walled parts;

[0029] Figure 8 It is a schematic diagram of the structure of the clamping device in this embodiment for locking and rotating thin-walled parts.

[0030] Description of reference numerals:

[0031] 100, long hood; 110, first cylindrical portion; 120, second cylindrical portion; 130, transition portion; 200, clamping device; 210, main body; 212, mounting portion; 213, supporting portion; 214, supporting block; 215, variable diameter inner hole; 218, annular flange; 220, first inner hole; 222, second inner hole; 224, through hole; 226, through groove; 228, annular groove; 240, fastener; 242, connecting portion; 244, tapered portion; 246, depression. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] like Figure 1 A schematic cross-sectional structure diagram of a rotating thin-walled part is shown, and the rotating thin-walled part can be a long wind hood 100, which includes a first cylindrical part 110, a second cylindrical part 120, and a transition part 130 extending between the first cylindrical part 110 and the second cylindrical part 120. The first cylindrical part 110 and the second cylindrical part 120 are cylindrical, and the transition part 130 is a transition arc surface connecting the first cylindrical part 110 and the second cylindrical part 120. The first cylindrical part 110 has a first inner diameter D1 and a first wall thickness. The second cylindrical part 120 has a second inner diameter D2 and a second wall thickness. The first inner diameter D1 of the first cylindrical part 110 is greater than the second inner diameter D2 of the second cylindrical part 120. The first wall thickness may be equal to or not equal to the second wall thickness. The wall thickness of the transition part 130 is equal to the first wall thickness of the first cylindrical part 110. In one example, the first inner diameter D1 of the first cylindrical part 110 is 49 mm, and the first wall thickness is 0.5 mm. The second inner diameter D2 of the second cylindrical portion 120 is 29.2 mm, and the second wall thickness is 0.4 mm. The wall thickness of the transition portion 130 is 0.5 mm. When viewed in cross section, the cross-sectional shape of the transition portion 130 is a 1 / 4 circle arc, with an inner radius of 7 mm and an outer radius of 7.5 mm. The long hood may be made of TC4 titanium alloy.

[0037] In the prior art, when processing the long wind hood 100, after the inner holes of the first cylindrical part 110 and the second cylindrical part 120 of the long wind hood 100 are processed, it is necessary to process a core shaft corresponding to the inner hole diameters of the first cylindrical part 110 and the second cylindrical part 120, and its two ends need to be sealed and locked with an annular structure. Due to the large number of parts and the complex force conditions, the concentricity needs to be calibrated multiple times, which reduces the clamping efficiency and processing efficiency. In addition, since the two ends are locked, the long wind hood 100 is prone to loosening during the processing, resulting in a decrease in the parts qualification rate.

[0038] In order to solve the above problems, Figure 2As shown, this embodiment provides a clamping device 200 including: a main body 210 and a fastener 240 .

[0039] like Figure 3 and Figure 4 As shown, the main body 210 is cylindrical in shape, and includes a coaxially arranged mounting portion 212 and a supporting portion 213, the mounting portion 212 is cylindrical, and the supporting portion 213 is cylindrical, and the coaxial arrangement of the mounting portion 212 and the supporting portion 213 means that the two can rotate along the same axis. The supporting portion 213 includes at least four support blocks 214 arranged at intervals along the circumferential direction, the support block 214 has an arc-shaped outer wall extending along the axial direction of the main body 210, the cross-section of the support block 214 is fan-shaped, and the arc-shaped outer walls of at least four support blocks 214 are combined into a circular outer wall, the support block 214 has an arc-shaped inner wall, and there is a variable diameter inner hole 215 between at least four support blocks 214, the variable diameter inner hole 215 is a circular hole, and the diameter of the variable diameter inner hole 215 gradually increases from the side of the support portion 213 close to the mounting portion 212 to the end of the support portion 213. The first cylindrical portion 110 of the long hood 100 can be mounted on the support portion 213 , the variable diameter inner hole 215 is concentric with the first cylindrical portion 110 and the second cylindrical portion 120 , and the opening of the variable diameter inner hole 215 is exposed in the second cylindrical portion 120 .

[0040] like Figure 5 and Figure 6 As shown, the fastener 240 has an outer wall surface that matches the shape of the variable diameter inner hole 215, and is suitable for extending into the variable diameter inner hole 215 and squeezing at least four support blocks 214 at the same time and moving in the direction away from the axis of the main body 210. The fastener 240 can enter the variable diameter inner hole 215 from the second cylindrical part 120, and fit with the inner wall of the variable diameter inner hole 215. The fastener 240 continues to extend into the variable diameter inner hole 215 and pushes at least four support blocks 214 in the direction away from the axis of the main body 210 at the same time. The arc-shaped outer walls of the at least four support blocks 214 move in the direction away from the axis of the main body 210 at the same time, so as to press the inner wall surface of the first cylindrical part 110, thereby locking the long wind hood 100.

[0041] The mounting portion 212 can be mounted on a chuck of a processing machine tool, and when the chuck rotates, the mounting portion 212 and the supporting portion 213 are driven to rotate along the same axis. After the inner hole processing of the rotating thin-walled part is completed, the rotating thin-walled part can be mounted on the support part 213 through the inner hole, and the arc-shaped outer walls of at least four support blocks 214 are fitted with the inner wall of the rotating thin-walled part. Then, the fastener 240 can be extended into the variable diameter inner hole 215 of the support part 213. Since the diameter of the variable diameter inner hole 215 gradually increases from the side of the support part 213 close to the mounting part 212 to the end of the support part 213, the fastener 240 is adapted to the shape of the variable diameter inner hole 215. During the process of the fastener 240 being extended, the outer wall of the fastener 240 will gradually squeeze the inner wall of the support block 214. The inner walls of at least four support blocks 214 are squeezed at the same time and move away from the axis. The arc-shaped outer walls of at least four support blocks 214 gradually press the inner wall of the rotating thin-walled part, thereby locking the rotating thin-walled part. Since at least four support blocks 214 simultaneously press the inner wall of the rotating thin-walled parts, it can ensure that the inner hole axis of the rotating thin-walled parts is highly consistent with the axis of the mounting portion 212 and the support portion 213, thereby solving the concentricity problem of the rotating thin-walled parts and eliminating the need for repeated proofreading, thereby improving the clamping efficiency and processing efficiency.

[0042] Since the arc-shaped outer wall of the support block 214 is attached to and locked with the inner wall of the rotating thin-walled part, the contact area and the effective locking pressure are increased, thereby overcoming the problem of the rotating thin-walled part becoming loose during the processing.

[0043] In addition, the above clamping device can be applied to short-axis or long-axis rotating thin-walled parts, and can also be applied to Figure 1 As shown in the figure, the rotating thin-walled parts have different inner diameters and outer diameters. The support block 214 can fully support most of the inner walls of the rotating thin-walled parts and can fit tightly. During the processing, the wall surface of the rotating thin-walled parts is not easily deformed.

[0044] The number of support blocks 214 can be determined according to actual conditions, for example Figure 3 As shown, the support portion 213 has eight support blocks 214, each support block 214 has an arc-shaped outer wall and an arc-shaped inner wall, the arc-shaped outer walls of the eight support blocks 214 equally divide the same circumference, and the arc-shaped inner walls of the eight support blocks 214 form a variable diameter inner hole 215, which is a circular hole, so that when the variable diameter inner hole 215 is subjected to pressure, each support block 214 simultaneously moves in a direction away from the axis of the main body 210, thereby locking the rotating thin-walled parts. Of course, the number of support blocks 214 can also be 4, 6 or more.

[0045] like Figure 4 and Figure 6As shown, the variable diameter inner hole 215 includes a first inner hole 220 and a second inner hole 222, the first inner hole 220 is formed in the mounting portion 212 and is coaxial with the mounting portion 212, the second inner hole 222 is a tapered hole, the inner wall of the support block 214 extends obliquely from the first inner hole 220 to the end of the support block 214, and a second inner hole 222 whose inner diameter increases from the first inner hole 220 to the end of the support block 214 is formed between at least four support blocks 214, and the fastener 240 has a connecting portion 242 and a tapered portion 244, the connecting portion 242 is adapted to the inner diameter of the first inner hole 220, and the outer wall of the tapered portion 244 is adapted to the shape of the second inner hole 222. Specifically, the inner diameter of the first inner hole 220 is fixed, and the outer diameter of the connecting portion 242 is also fixed. The connecting portion 242 is coaxial with the first inner hole 220, which is conducive to calibrating the contact position between the conical portion 244 and the second inner hole 222, so that each support block 214 is subjected to the same pressure, thereby ensuring that the inner hole axis of the rotating thin-walled part is always highly consistent with the axis of the main body 210 to ensure concentricity.

[0046] like Figure 4 and Figure 6 As shown, in this embodiment, the first inner hole 220 has an internal thread T1, and the connecting portion 242 has an external thread T2. The cooperation of the internal thread T1 and the external thread T2 is conducive to ensuring that the fastener 240 can extend into the variable diameter inner hole 215 along the axial direction of the main body 210. The squeezing force of the tapered portion 244 on the second inner hole 222 can be controlled by reasonably setting the thread angle and pitch. At the same time, it can also prevent the fastener 240 from coming out of the variable diameter inner hole 215.

[0047] In this embodiment, the outer wall of the tapered portion 244 is a smooth surface, and the inner wall of the second inner hole 222 is a smooth surface, which is conducive to the complete fit between the tapered portion 244 and the second inner hole 222, and is also conducive to reducing the wear of the tapered portion 244 and the second inner hole 222.

[0048] In this embodiment, the length dimension of the tapered portion 244 in the axial direction of the main body 210 is greater than the length dimension of the second inner hole 222 in the axial direction of the main body 210. Therefore, after the inner wall of the second inner hole 222 is completely supported by the tapered portion 244, when the tapered portion 244 further enters the second inner hole 222, the support block 214 will be squeezed away from the axis of the main body 210, avoiding the formation of a gap between the second inner hole 222 and the tapered portion 244, and further ensuring the synchronous movement of each support block 214.

[0049] like Figure 4 and Figure 6As shown, in the present embodiment, the angle between the inner wall of the second inner hole 222 and the axis of the main body 210 is in the range of 10° to 30°. For example, the angle may be 10°, 12°, 14°, 16°, 18°, 20°, 22°, 24°, 26°, 28° or 30°. Correspondingly, the angle between the outer wall of the tapered portion 244 and the axis of the main body 210 is also in the range of 10° to 30°. The tapers of the second inner hole 222 and the tapered portion 244 are kept consistent. Such an arrangement can ensure that the tapered portion 244 can slowly pressurize the second inner hole 222 when rotating with the connecting portion 242. At the same time, the arc-shaped outer wall of the support block 214 can also slowly pressurize the inner hole of the rotating thin-walled parts until the support block 214 locks the rotating thin-walled parts, thereby avoiding deformation of the rotating thin-walled parts caused by excessive pressure.

[0050] like Figure 4 and Figure 7 As shown, in this embodiment, the end of the support portion 213 has an arc chamfer, which can further fit the inner hole of the rotating thin-walled part, for example, fit the inner wall of the transition portion 130 of the long hood 100, so as to further increase the support area of ​​the inner hole of the rotating thin-walled part. Figure 7 As shown in the figure, after locking the rotating thin-walled parts, the outer wall of the rotating thin-walled parts can be processed, and the outer wall of the rotating thin-walled parts can be processed. Figure 7 The dotted line portion is processed to meet the wall thickness requirements of different parts of the long hood 100. Figure 8 This is a schematic diagram of a long wind hood 100 that has been processed, which is used to prevent the outer wall of rotating thin-walled parts from being deformed due to excessive processing force.

[0051] In this embodiment, the outer diameter of the support portion 213 matches the first inner diameter D1 of the first cylindrical portion 110 of the long hood 100. For example, the outer diameter of the support portion 213 can be slightly smaller than the first inner diameter D1, and can be 0.01mm, 0.005mm, 0.004mm, 0.003mm, 0.002mm or 0.001mm smaller. This is conducive to the first cylindrical portion 110 being mounted on the support portion 213 without wear. When the subsequent fastener 240 squeezes the support portion 213, the support portion 213 can lock the first cylindrical portion 110.

[0052] like Figure 3 As shown, in this embodiment, there are through slots 226 between adjacent support blocks 214, and the number of through slots 226 is consistent with the number of support blocks 214, for example, 4, 6, 8 or more. The provision of through slots 226 is conducive to reducing the root strength of the support block 214, so that the fastener 240 can push the support block 214 to deform.

[0053] like Figure 3As shown, in this embodiment, the through slot 226 is provided with a through hole 224 near the edge of the mounting portion 212, and the number of the through holes 224 is consistent with the number of the through slots 226, for example, it can be 4, 6, 8 or more. The provision of the through hole 224 is conducive to further reducing the root strength of the support block 214, so that it is convenient for the fastener 240 to push the support block 214 to deform.

[0054] like Figure 5 As shown, in this embodiment, the end surface of the fastener 240 facing away from the mounting portion 212 has a recess 246. The recess 246 is configured to engage a tool such as a wrench, so that the fastener 240 can be more easily rotated relative to the main body 210 when the fastener 240 is assembled with the main body 210.

[0055] like Figure 5 As shown, in this embodiment, the recess 246 is a hexagonal recess, and a hexagonal wrench can be used to control the rotation of the fastener 240.

[0056] like Figure 3 and Figure 4 As shown, in this embodiment, an annular flange 218 is coaxially arranged between the mounting portion 212 and the supporting portion 213. The annular flange 218 is used to separate the mounting portion 212 and the supporting portion 213. When the chuck of the processing machine tool contacts the annular flange 218, it indicates that the clamping is in place.

[0057] like Figure 3 and Figure 4 As shown, in this embodiment, an annular groove 228 is provided at a position of the support portion 213 near the annular flange 218. The annular groove 228 can further reduce the root strength of the support block 214 so that the fastener 240 can easily apply force to lock the rotating thin-walled parts.

[0058] In this embodiment, the body 210 and the fastener 240 may be made of a wear-resistant material, such as H62 copper alloy.

[0059] 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: A main body (210) comprises a coaxially arranged mounting portion (212) and a supporting portion (213), wherein the supporting portion (213) comprises at least four supporting blocks (214) arranged at intervals in a circumferential direction, wherein the supporting block (214) has an arc-shaped outer wall extending along the axial direction of the main body (210), wherein the cross section of the supporting block (214) is fan-shaped, wherein the arc-shaped outer walls of at least four supporting blocks (214) are combined into a circular outer wall, and wherein a variable diameter inner hole (215) is provided between at least four supporting blocks (214), wherein the diameter of the variable diameter inner hole (215) gradually increases from a side of the supporting portion (213) close to the mounting portion (212) to an end of the supporting portion (213); The fastener (240) has an outer wall surface that matches the shape of the variable diameter inner hole (215), and is suitable for extending into the variable diameter inner hole (215) and simultaneously squeezing at least four of the support blocks (214) and moving in an axial direction away from the main body (210).

2. The clamping device according to claim 1, characterized in that: The variable diameter inner hole (215) comprises a first inner hole (220) and a second inner hole (222), wherein the first inner hole (220) is formed in the mounting portion (212) and is coaxial with the mounting portion (212), the inner wall of the support block (214) extends obliquely from the first inner hole (220) to the end of the support block (214), and the second inner hole (222) whose inner diameter increases from the first inner hole (220) to the end of the support block (214) is formed between at least four of the support blocks (214); the fastener (240) comprises a connecting portion (242) and a tapered portion (244), wherein the connecting portion (242) is adapted to the inner diameter of the first inner hole (220), and the outer wall of the tapered portion (244) is adapted to the shape of the second inner hole (222).

3. The clamping device according to claim 2, characterized in that: The first inner hole (220) has an internal thread, and the connecting portion (242) has an external thread.

4. The clamping device according to claim 2, characterized in that: The angle between the inner wall of the second inner hole (222) and the axis of the main body (210) ranges from 10° to 30°.

5. The clamping device according to claim 1, characterized in that: A through slot (226) is provided between adjacent support blocks (214).

6. The clamping device according to claim 5, characterized in that: The through slot (226) is provided with a through hole (224) near the edge of the mounting portion (212).

7. The clamping device according to claim 1, characterized in that: The end surface of the fastener (240) facing away from the mounting portion (212) has a recess (246).

8. The clamping device according to claim 7, characterized in that: The recess (246) is a hexagonal recess.

9. The clamping device according to any one of claims 1 to 8, characterized in that: An annular flange (218) is coaxially arranged between the mounting portion (212) and the supporting portion (213).

10. The clamping device according to claim 9, characterized in that: An annular groove (228) is formed on the support portion (213) at a position close to the annular flange (218).

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