Clamp, machine tool and method for adjusting coaxiality of clamp

Abstract

The application relates to a clamp, a machine tool and a coaxiality adjusting method of the clamp. The clamp comprises a supporting shaft which is longitudinally long along a first direction; a plurality of expansion blocks which are movably arranged on the supporting shaft in a circumferential direction of the supporting shaft; and all the expansion blocks can be extended or retracted along a second direction intersecting the first direction relative to the side surface of the supporting shaft. When a pipe workpiece needs to be clamped by the clamp, the supporting shaft is inserted into the workpiece, and then the expansion blocks are extended so that the expansion blocks abut against the side wall in the workpiece, thereby fixing the workpiece on the supporting shaft. The outer surface of the workpiece is in an unobstructed state, so that the outer surface of the workpiece can be machined by a tool, and the workpiece does not need to be turned over, thereby improving the machining efficiency and machining precision of the workpiece.

Description

Technical Field

[0001] This application relates to the field of lathe technology, and in particular to fixtures, machine tools, and methods for adjusting the coaxiality of fixtures. Background Technology

[0002] In the field of mechanical manufacturing, tubular workpieces are widely used. Currently, in lathe machining processes, three-jaw chucks and four-jaw chucks are typically used as fixtures for machining tubular workpieces. One end of the workpiece is clamped by the fixture, and the remaining part is machined. After machining, the workpiece is axially turned and clamped for further machining.

[0003] During the process of turning and clamping the workpiece, not only is it necessary to re-set the tool, resulting in low workpiece processing efficiency, but the movement of the workpiece will also cause deviations in the coaxiality of the clamping, resulting in poor workpiece processing accuracy. Summary of the Invention

[0004] Therefore, it is necessary to provide a method for adjusting the coaxiality of the fixture, machine tool, and fixture to address the problem that existing fixtures can lead to low workpiece processing efficiency and poor processing efficiency.

[0005] A clamp, comprising:

[0006] The support shaft extends longitudinally along the first direction;

[0007] Multiple expansion blocks are circumferentially mounted on the support shaft, and each expansion block can extend or retract relative to the side of the support shaft along a second direction intersecting the first direction.

[0008] In one embodiment, the support shaft is provided with a mounting hole extending longitudinally along a first direction and a plurality of expansion holes extending through along a second direction, and all the expansion blocks are movably installed in the plurality of expansion holes;

[0009] The clamp also includes a clamping wedge, which is movably mounted on the mounting hole along a first direction and connected to all the expansion blocks. During the movement of the clamping wedge, it can drive all the expansion blocks to extend or retract relative to the support shaft in the second direction.

[0010] In one embodiment, the clamping wedge is provided with a plurality of first inclined surfaces that intersect both the first direction and the second direction;

[0011] Each of the expansion blocks is provided with a second inclined surface, and all the second inclined surfaces correspond one-to-one with all the first inclined surfaces. Each second inclined surface is arranged parallel to the corresponding first inclined surface. During the movement of the clamping wedge block, each second inclined surface can abut against the corresponding first inclined surface.

[0012] In one embodiment, the clamp further includes a plurality of limiting members corresponding one-to-one with all the expansion blocks, each of the limiting members being fixedly installed on the support shaft and located on the movement path of the corresponding expansion block.

[0013] In one embodiment, the clamp further includes a plurality of elastic elements, each of which is disposed between the expansion block and the corresponding limiting element. When the expansion block extends outward relative to the side of the support shaft, the elastic element is in a compressed state.

[0014] In one embodiment, the clamp further includes a push-pull member that is controllably movable within the mounting hole along the first direction, and includes a first stepped portion, a connecting portion, and a second stepped portion connected in sequence.

[0015] The clamping wedge has a push-pull hole that extends through in a first direction. The first stepped portion and the second stepped portion abut against the two ends of the clamping wedge in the first direction, respectively. The connecting portion passes through the push-pull hole.

[0016] In one embodiment, a preset gap exists between the connecting portion and the inner wall of the push-pull hole.

[0017] In one embodiment, the clamp further includes a positioning sleeve, which is fitted and fixedly installed on the support shaft and spaced apart from all the expansion blocks along a first direction.

[0018] In one embodiment, the positioning sleeve is provided with a frustum, and the larger diameter end of the frustum is located on the side of the smaller diameter end away from the expansion block.

[0019] In one embodiment, the clamp further includes a plurality of adjusting members, and the positioning sleeve is provided with a plurality of adjusting holes circumferentially around the axis of the support shaft, and each of the adjusting holes is provided with a thread.

[0020] All the adjusting components are threadedly connected to all the adjusting holes, and each adjusting component can abut against the support shaft during its movement within the corresponding adjusting hole.

[0021] A machine tool comprising a fixture as described in any of the preceding claims.

[0022] A method for adjusting the coaxiality of a clamp, applicable to the support shaft and the positioning sleeve in any of the clamps described above, comprising the following steps:

[0023] With the dial indicator fixed and its probe in contact with the side of the positioning sleeve, rotate the support shaft;

[0024] Adjust the coaxiality of the positioning sleeve and the support shaft according to the fluctuation of the dial indicator value.

[0025] In one embodiment, the step of adjusting the coaxiality of the positioning sleeve and the clamping wedge specifically includes:

[0026] The coaxiality of the positioning sleeve and the support shaft is adjusted by at least one of the adjustment components until the value of the dial indicator meets the preset condition after the support shaft rotates N times.

[0027] In one embodiment, before adjusting the coaxiality of the positioning sleeve and the support shaft based on the fluctuation of the dial indicator reading, the method further includes the following step:

[0028] Adjust the position of at least one adjusting member so that each adjusting member contacts the support shaft.

[0029] In practical use, when clamping tubular workpieces, the aforementioned fixture can be used by first retracting the expansion block to insert the support shaft into the workpiece, with one end of the workpiece abutting against the positioning sleeve. Then, the expansion block is extended, abutting against the inner sidewall of the workpiece, thus fixing the workpiece to the support shaft. This internal support and fixation of the workpiece by the expansion block ensures that the outer surface of the workpiece is unobstructed, allowing the cutting tool to machine the outer surface without needing to turn the workpiece around, saving time on re-clamping and tool re-setting, thereby improving machining efficiency. Furthermore, since the workpiece does not need to be moved again after being fixed until machining is complete, there is no problem with coaxiality deviation during clamping, further improving machining accuracy. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the clamp when the expansion block retracts in one embodiment of the application.

[0031] Figure 2 This is a schematic diagram of the structure of the clamp when the expansion block extends in one embodiment of the application.

[0032] Figure 3 for Figure 1 A schematic diagram of the fixture clamping the workpiece in the embodiment.

[0033] Figure 4 for Figure 1 An exploded view of the fixture in the embodiment.

[0034] Figure 5 This is a schematic diagram illustrating the adjustment of the coaxiality of the positioning sleeve and the support shaft in one embodiment of this application.

[0035] Figure 6 This is a step diagram of a method for adjusting the coaxiality of a clamp in one embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] Workpiece 100; Center 110;

[0038] Support shaft 10; mounting hole 11; expansion hole 12;

[0039] 20; second inclined surface 21; limiting groove 22; base 23; side 24;

[0040] Positioning sleeve 30; frustum 31; adjusting hole 32; adjusting component 33;

[0041] Clamping wedge 40; First inclined surface 41; Push-pull component 42; First stepped portion 43; Connecting portion 44; Second stepped portion 45; Push-pull hole 46; Push rod 47; Pull rod 48;

[0042] Limiting component 50; Elastic component 51;

[0043] Dial indicator 60; graduation plate 61; wrench 62;

[0044] First direction X; second direction Y. Detailed Implementation

[0045] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0046] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0047] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0051] See Figure 1 and Figure 2 The clamp provided in one embodiment of this application includes a support shaft 10, expansion blocks 20 and positioning sleeve 30. The support shaft 10 extends longitudinally along a first direction X. The expansion blocks 20 include a plurality of blocks, and all expansion blocks 20 are movably mounted on the support shaft 10 around the circumference of the support shaft 10. Each expansion block 20 can extend or retract relative to the side of the support shaft 10 along a second direction Y intersecting the first direction X.

[0052] In practical use, please refer to Figure 3 When clamping a tubular workpiece 100 using a fixture, the expansion block 20 can be retracted first, allowing the support shaft 10 to be inserted into the workpiece 100. Then, the expansion block 20 is extended, abutting against the inner sidewall of the workpiece 100, thus fixing the workpiece 100 onto the support shaft 10. In this way, by supporting and fixing the interior of the workpiece 100 with the expansion block 20, the outer surface of the workpiece 100 is completely unobstructed, facilitating machining of the outer surface without requiring the workpiece 100 to be turned around, saving time spent on turning, clamping, and resetting the tool, thereby improving the machining efficiency of the workpiece 100. Furthermore, since the workpiece 100 does not need to be moved again after being fixed until machining is completed, there is no problem with coaxiality deviation during clamping, thus improving the machining accuracy of the workpiece 100.

[0053] In some embodiments of this application, the support shaft 10 has a mounting hole 11 extending longitudinally along the first direction X, and a plurality of expansion holes 12 extending through along the second direction Y. All expansion blocks 20 are movably mounted in the plurality of expansion holes 12. The fixture also includes a clamping wedge 40, which is movably mounted in the mounting hole 11 along the first direction X and connected to all expansion blocks 20. During the movement of the clamping wedge 40, it can drive all expansion blocks 20 to extend or retract relative to the support shaft 10 in the second direction Y. In this way, the extension and retraction movements of all expansion blocks 20 are converted into the movement of the clamping wedge 40 along the first direction X. Controlling the movement of the clamping wedge 40 can indirectly control the movement of all expansion blocks 20, eliminating the need to move each expansion block 20 individually, improving the movement efficiency of all expansion blocks 20, and thus improving the clamping efficiency of the workpiece 100.

[0054] In some embodiments, the clamping wedge 40 is provided with a plurality of first inclined surfaces 41 that intersect both the first direction X and the second direction Y. Each expansion block 20 is provided with a second inclined surface 21, and all the second inclined surfaces 21 correspond one-to-one with all the first inclined surfaces 41. Each second inclined surface 21 is arranged parallel to the corresponding first inclined surface 41. During the movement of the clamping wedge 40, each second inclined surface 21 can abut against the corresponding first inclined surface 41.

[0055] In actual use, when the clamping wedge 40 drives each first inclined surface 41 to move toward the corresponding second inclined surface 21, as the first inclined surface 41 contacts the corresponding second inclined surface 21, the clamping wedge 40 will compress the space of the expansion block 20, causing the expansion block 20 to move away from the clamping wedge 40, so that the expansion block 20 extends out of the expansion hole 12. As the clamping wedge 40 continues to move, the contact area between the first inclined surface 41 and the second inclined surface 21 increases, the clamping wedge 40 compresses more space of the expansion block 20, and the expansion block 20 extends further out of the expansion hole 12, until all the expansion blocks 20 press against the inner sidewall of the workpiece 100, thus completing the fixation of the workpiece 100 by all the expansion blocks 20.

[0056] When the fixture needs to release the workpiece 100, the clamping wedge 40 can be controlled to move each of the first inclined surfaces 41 away from the second inclined surface 21, so that the expansion block 20 retracts into the expansion hole 12. As the clamping wedge 40 gradually moves away from the expansion block 20, the expansion block 20 gradually loses its clamping force on the workpiece 100 until all the expansion blocks 20 can no longer clamp the workpiece 100, thus allowing the workpiece 100 to be removed.

[0057] In some specific embodiments, to prevent the clamping wedge 40 from pushing the expansion block 20 out of the expansion hole during movement, causing the expansion block 20 to fall off the fixture and affecting the clamping effect of the workpiece 100, the fixture also includes multiple limiting members 50 corresponding to all the expansion blocks 20. Each limiting member 50 is fixedly installed on the support shaft 10 and is located on the movement path of the corresponding expansion block 20, so as to limit the movement range of the expansion block 20 through the limiting block, and prevent the expansion block 20 from falling off the fixture.

[0058] Specifically, each expansion block 20 is provided with a limiting groove 22, the longitudinal direction of which intersects with the second direction Y. Each limiting member 50 is fixedly installed on the support shaft 10 and passes through the limiting groove 22 of the corresponding expansion block 20. The expansion block 20 includes a base 23 and two side portions 24. The bottom has the aforementioned second inclined surface 21 at one end in the second direction Y, and two side portions 24 are provided on the other side, forming a limiting groove 22 between the two side portions 24.

[0059] In actual use, when the clamping wedge 40 pushes the expansion block 20 out of the expansion hole 12, the base 23 and the two side portions 24 move along the second direction Y. The limiting member 50 passes through the limiting groove 22, that is, the limiting member 50 is located between the two side portions 24. Therefore, the limiting member 50 does not prevent the two side portions 24 from moving along the second direction Y, so that the two side portions 24 can press against the inner side wall of the workpiece 100. However, if the expansion block 20 continues to move, the limiting member 50 will abut against the base 23, that is, against the bottom of the limiting groove 22, to prevent the expansion block 20 from continuing to move and to prevent the expansion block 20 from disengaging from the expansion hole 12.

[0060] Specifically, in some embodiments, see [link to relevant documentation]. Figure 1 and Figure 3 The clamp also includes multiple elastic elements 51, each of which is disposed between the expansion block 20 and the corresponding limiting element 50. When the expansion block 20 extends out relative to the side of the support shaft 10, the elastic element 51 is in a compressed state. That is, when the clamping wedge block 40 pushes the expansion block 20 out of the expansion hole 12, it also compresses the elastic element 51. Thus, when the clamping push block stops pushing the expansion block 20, the elastic element 51 will restore its deformation, thereby driving the expansion block 20 to move away from the limiting element 50, that is, driving the expansion block 20 to retract into the expansion hole 12. Thus, when the clamping wedge 40 drives each first inclined surface 41 to move away from the second inclined surface 21, the expansion block 20 will automatically retract into the expansion hole 12. If the elastic element 51 is not provided, although the expansion block 20 will no longer press the workpiece 100, the expansion block 20 may still extend out of the expansion hole 12 and abut against the workpiece 100 under the action of gravity, thereby hindering the separation of the workpiece 100 from the fixture. However, the elastic element 51 can ensure that the expansion block 20 can retract, prevent the expansion block 20 from abutting against the workpiece 100, and improve the smoothness of the separation of the workpiece 100 from the fixture.

[0061] Optionally, the elastic element 51 is a spring, which is disposed in the limiting groove 22, with one end of the spring abutting against the limiting element 50 and the other end abutting against the base 23 of the expansion block 20.

[0062] In some embodiments, the clamp further includes a push-pull member 48, which is controllably movable within the mounting hole 11 along a first direction X, and includes a first stepped portion 43, a connecting portion 44, and a second stepped portion 45 connected in sequence. A push-pull hole 46 is provided on the clamping wedge 40, extending through along the first direction X. The first stepped portion 43 and the second stepped portion 45 respectively abut against the two ends of the clamping wedge 40 in the first direction X, and the connecting portion 44 passes through the push-pull hole 46.

[0063] Specifically Figure 1In this embodiment, when the push-pull member 48 moves to the left, the clamping wedge 40 can be driven to move to the left by the second step 45, and when the push-pull member 48 moves to the right, the clamping wedge 40 can be driven to move to the right by the first step 43. Thus, by controlling the movement of the push-pull member 48, the movement of the clamping wedge 40 can be controlled, thereby controlling the extension and retraction of the expansion block 20.

[0064] As can be seen from the above, during the movement of the clamping wedge 40, all the expansion blocks 20 extend and retract simultaneously. Therefore, the extension and retraction amounts of all the expansion blocks 20 are consistent. However, in actual use, the inner wall of the workpiece 100 is not a smooth curved surface and may have protrusions relative to the inner wall. If one of the expansion blocks 20 comes into contact with this protrusion, the clamping wedge 40 cannot continue to move, but at this time the remaining expansion blocks 20 do not press against the inner wall of the workpiece 100, which will affect the clamping effect of the workpiece 100.

[0065] Therefore, a preset gap is provided between the connecting part 44 and the inner wall of the push-pull hole 46. If, during the process of moving all the expansion blocks 20, one of the expansion blocks 20 abuts against the protrusion on the inner wall of the workpiece 100, while the other expansion blocks 20 remain on the inner wall of the workpiece 100, the clamping wedge 40 can continue to move. Since the expansion block 20 abutting against the protrusion has already abutted against the workpiece 100, the continued movement of the clamping wedge 40 will cause the expansion block 20 to press against the clamping wedge 40 in the opposite direction, thereby reducing the preset gap between the clamping wedge 40 and the connecting part 44. The reduction of the preset gap absorbs the relative movement between the expansion block 20 and the clamping wedge 40 until the clamping wedge 40 moves until all the remaining expansion blocks 20 abut against the inner wall of the workpiece 100, thus completing the fixation of the workpiece 100.

[0066] Furthermore, for ease of installation, the push-pull component 48 includes a push rod 47 and a pull rod 48. The push rod 47 is provided with a first step portion 43, and the pull rod 48 is provided with a connecting portion 44 and a second step portion 45. The pull rod 48 is threadedly connected to the push rod 47. By separating the push rod 47 and the pull rod 48, it is easy to pass the connecting portion 44 through the push-pull hole 46 of the clamping wedge block 40, thereby facilitating the installation of the clamping wedge block 40.

[0067] In the embodiments of this application, the fixture further includes a positioning sleeve 30, which is sleeved and fixedly installed on the support shaft 10 and spaced apart from all the expansion blocks 20 along the first direction X. The positioning sleeve 30 is used to abut against one end of the workpiece 100 to position the workpiece 100 on the fixture, while the other end of the workpiece 100 can be fixed by the center 110 on the machine tool, and the interior of the workpiece 100 is fixed by a plurality of expansion blocks 20.

[0068] The positioning sleeve 30 is provided with a frustum 31, with the larger diameter end of the frustum 31 located on the side away from the smaller diameter end of the expansion block 20. The larger diameter end refers to the end of the frustum 31 with a larger radius, and the smaller diameter end refers to the end of the frustum 31 with a smaller radius. When the support shaft 10 passes through the inside of the tubular workpiece 100, the end of the workpiece 100 abuts against the frustum 31. The frustum 31 automatically adjusts the contact area between the workpiece 100 and the positioning sleeve 30, ensuring that the positions of workpieces 100 of the same type on the positioning sleeve 30 remain consistent, thereby improving the accuracy of the fixture in fixing the workpiece 100.

[0069] In practical use, to ensure the accuracy of turning, the axis of the workpiece 100 usually needs to be coaxial with the axis of the support shaft 10. Therefore, the axis of the frustum 31 used to position the workpiece 100 also needs to be coaxial with the support shaft 10. The coaxiality between the frustum 31 and the support shaft 10 directly affects the machining accuracy of the workpiece 100. To this end, in some embodiments, the fixture also includes multiple adjusting members 33. The positioning sleeve 30 is circumferentially provided with multiple adjusting holes 32 around the axis of the support shaft 10. All adjusting members 33 are threadedly connected to all adjusting holes 32. Each adjusting member 33 can abut against the support shaft 10 during its movement within the corresponding adjusting hole 32.

[0070] All the adjusting components 33 can be used to adjust the coaxiality of the positioning sleeve 30 and the support shaft 10, thereby adjusting the coaxiality of the frustum surface 31 and the support shaft 10. Specifically, the positioning sleeve 30 has a fixing hole, the support shaft 10 passes through the fixing hole, and the adjusting hole 32 extends through the fixing hole. The movement of the adjusting component 33 within the adjusting hole 32 allows it to extend into the fixing hole and abut against the support shaft 10. By contacting the support shaft 10 with one of the adjusting components 33, the gap between the inner wall of the fixing hole and the surface of the support shaft 10 is adjusted when the positioning sleeve 30 is positioned at that adjusting component 33, thereby adjusting the coaxiality of the positioning sleeve 30 and the support shaft 10 at that position. By using multiple adjusting components 33 together, the coaxiality of the positioning sleeve 30 and the support shaft 10 can be precisely adjusted. Optionally, the adjusting component 33 is a set screw; in other embodiments, it can also be a threaded component such as a bolt or stud.

[0071] This application also provides a machine tool that includes the above-mentioned fixture. Since the machine tool includes all the technical features of the above-mentioned fixture, it possesses all the technical effects of the above-mentioned fixture, which will not be repeated here.

[0072] As per the same concept in this application, see Figure 5 and Figure 6 This application also provides a method for adjusting the coaxiality of a clamp, applicable to the support shaft 10 and positioning sleeve 30 of the clamp in the above embodiment, which includes the following steps:

[0073] S1: With the dial indicator 60 fixed and the probe of the dial indicator 60 in contact with the side of the positioning sleeve 30, rotate the support shaft 10.

[0074] S2: Adjust the coaxiality of the positioning sleeve 30 and the clamping wedge block 40 according to the fluctuation of the dial indicator 60.

[0075] Specifically, the dial indicator 60 is used to convert the displacement of the probe into a numerical value through rotational motion. In step S1, the dial indicator 60 can be mounted on a stable part of the machine tool. If the positioning sleeve 30 is coaxial with the support shaft 10, the position of the probe will remain unchanged after rotating the support shaft 10, so the value of the dial indicator 60 will not move or will move only slightly. If the positioning sleeve 30 is not coaxial with the support shaft 10, the position of the probe will move relative to the support shaft 10 with the surface of the positioning sleeve 30, so the value of the dial indicator 60 will fluctuate significantly. Based on this, in step S2, if the fluctuation of the dial indicator 60 is very obvious when the support shaft 10 rotates to a certain range, it indicates that the coaxiality of the positioning sleeve 30 and the support shaft 10 within that range needs to be adjusted.

[0076] It should be noted that the coaxiality adjustment method between the positioning sleeve 30 and the support shaft 10 can be selected according to the actual installation method of the positioning sleeve 30. For example, in some embodiments, if the positioning sleeve 30 and the support shaft 10 are connected by multiple bolts and flanges, the position of each bolt and flange can be adjusted to adjust the coaxiality between the positioning sleeve 10 and the support shaft 10.

[0077] In some embodiments, the step of adjusting the coaxiality of the positioning sleeve 30 and the clamping wedge 40 specifically includes:

[0078] The coaxiality between the positioning sleeve 30 and the support shaft 10 is adjusted by at least one adjusting member 33 until the value of the dial indicator 60 meets the preset condition when the support shaft 10 rotates N times.

[0079] The above preset conditions can be selected according to the actual machining accuracy, such as the micrometer 60 value fluctuation not exceeding 0.005mm. Since the adjusting part 33 is threadedly connected to the adjusting hole 32, rotating the adjusting part 33 will cause it to move within the adjusting hole 32 until it abuts against the support shaft 10. If the adjusting part 33 is rotated further at this time, it will raise the positioning sleeve 30, thereby adjusting the coaxiality between the positioning sleeve 30 and the support shaft 10.

[0080] Multiple adjustment pieces 33 can adjust the coaxiality of different parts of the positioning sleeve 30 with the support shaft 10. Based on the fluctuation of the dial indicator 60 value at different parts of the positioning sleeve 30, the adjustment piece 33 at the corresponding position can be selected to adjust the coaxiality of that part with the support shaft 10.

[0081] Specifically, taking a fixture comprising three adjusting members 33 as an example, the three adjusting members 33 divide the side of the positioning sleeve 30 into three arcs. Rotating the support shaft 10 causes the dial indicator 60 to monitor the curvature of the three arcs. If the dial indicator 60 shows a large fluctuation when measuring one of the arcs, the two adjusting members 33 located at both ends of that arc are rotated to adjust the gap between the positioning sleeve 30 at that arc and the support shaft 10, thereby adjusting the coaxiality between the arc and the support shaft 10. This process is repeated to adjust the coaxiality of the other two arcs with the support shaft 10 until, after rotating the support shaft 10 one revolution, the fluctuation of the dial indicator 60 does not exceed 0.005 mm.

[0082] Furthermore, to more precisely adjust the coaxiality of the positioning sleeve 30 and the support shaft 10, a graduated disc 61 and a wrench 62 can be used when rotating the adjusting component 33. The top of the adjusting component 33 is equipped with a graduated disc 61, which has multiple scale divisions. When rotating the adjusting component 33, the wrench 62 can control the distance the adjusting component 33 moves within the adjusting hole 32 by observing the number of scale divisions it passes through, thereby controlling the coaxiality of the positioning sleeve 30 at that position with the support shaft 10. For example, if the graduated disc 61 has 250 scale divisions, with one division representing 1.44°, and the pitch of the adjusting component 33 is 0.5mm, then each scale division passed by the wrench 62 represents a 0.002mm movement of the adjusting component 33, increasing the distance between the portion of the positioning sleeve 30 located on the adjusting component 33 and the support shaft 10 by 0.002mm.

[0083] Furthermore, when rotating the adjustment component 33 causes the support shaft 10 to rotate one revolution, and the maximum fluctuation of the dial indicator 60 does not exceed a preset value, each adjustment component 33 can be tightened by the torque wrench 62 to give each adjustment component 33 a certain locking force.

[0084] In some embodiments, step S0 is included before step S1:

[0085] Adjust the position of at least one adjusting member 33 so that each adjusting member 33 contacts the support shaft 10.

[0086] If there is a gap between the adjusting member 33 and the support shaft 10, although the adjusting member 33 is rotated, the positioning sleeve 30 does not move relative to the support shaft 10, which makes the adjustment inaccurate. However, after step S0, when it is necessary to adjust the coaxiality of the positioning sleeve 30 and the support shaft 10, the positioning sleeve 30 moves the same distance as the adjusting member 33, ensuring the accuracy of the adjustment.

[0087] Specifically, the torque wrench 62 can be used to determine whether the adjusting member 33 is in contact with the support shaft 10. When the torque wrench tightens the adjusting member 33, if the adjusting member 33 is not in contact with the support shaft 10, the torque of the torque wrench is at a small value. If the adjusting member 33 is in contact with the support shaft 10, the torque of the torque wrench will suddenly increase. At this time, stop rotating the adjusting member 33, and the adjusting member 33 will be in the position of just contacting the support shaft 10.

[0088] The above-mentioned method for adjusting the coaxiality of the fixture involves measuring the coaxiality of the positioning sleeve 30 and the support shaft 10 using a dial indicator 60, and adjusting the coaxiality of the positioning sleeve 30 and the support shaft 10 according to the adjusting component 33. This improves the coaxiality of the positioning sleeve 30 and the support shaft 10, thereby improving the coaxiality of the workpiece 100 and the support shaft 10, and improving the machining accuracy of the workpiece 100.

[0089] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A clamp, characterized in that, The clamp includes: Support shaft (10) extends longitudinally along the first direction (X); Multiple expansion blocks (20) are circumferentially mounted on the support shaft (10), and each expansion block (20) can extend or retract relative to the side of the support shaft (10) along a second direction (Y) intersecting the first direction (X); The support shaft (10) is provided with a mounting hole (11) extending longitudinally along the first direction (X) and a plurality of expansion holes (12) extending through along the second direction (Y). All the expansion blocks (20) are movably installed in the plurality of expansion holes (12). The clamp also includes a clamping wedge (40), which is movably installed in the mounting hole (11) along the first direction (X) and connected to all the expansion blocks (20). During the movement of the clamping wedge (40), it can drive all the expansion blocks (20) to extend or retract relative to the support shaft (10) in the second direction (Y). The clamping wedge (40) is provided with a plurality of first inclined surfaces (41) that intersect both the first direction (X) and the second direction (Y). Each of the expansion blocks (20) is provided with a second inclined surface (21), all the second inclined surfaces (21) correspond one-to-one with all the first inclined surfaces (41), each second inclined surface (21) is arranged parallel to the corresponding first inclined surface (41), and during the movement of the clamping wedge block (40), each second inclined surface (21) can abut against the corresponding first inclined surface (41); The clamp also includes a plurality of limiting members (50) corresponding one-to-one with all the expansion blocks (20). Each of the limiting members (50) is fixedly installed on the support shaft (10) and is located on the movement path of the corresponding expansion block (20). The clamp also includes a plurality of elastic elements (51), each of the elastic elements (51) being disposed between the expansion block (20) and the corresponding limiting element (50). When the expansion block (20) extends out relative to the side of the support shaft (10), the elastic element (51) is in a pressed state. Each of the expansion blocks (20) is provided with a limiting groove (22) through it, and the longitudinal direction of the limiting groove (22) intersects with the second direction (Y); each of the limiting members (50) is fixedly installed on the support shaft (10) and passes through the limiting groove (22) of the corresponding expansion block (20); wherein, the expansion block (20) includes a base (23) and two side portions (24), the base (23) is provided with a second inclined surface (21) at one end of the second direction Y, and two side portions (24) are provided on the other side, and the limiting groove (22) is formed between the two side portions (24). When the clamping wedge (40) pushes the expansion block (20) out of the expansion hole (12), the base (23) and the two sides (24) move along the second direction Y. The limiting member (50) passes through the limiting groove (22) and is located between the two sides (24). The limiting member (50) does not prevent the two sides (24) from moving along the second direction (Y) so that the two sides (24) press against the inner sidewall of the workpiece (100). If the expansion block (20) continues to move, the limiting member (50) will abut against the base (23) to prevent the expansion block (20) from continuing to move and prevent the expansion block (20) from detaching from the expansion hole (12).

2. The clamp according to claim 1, characterized in that, The clamp also includes a push-pull member (48), which is controllably movable in the mounting hole (11) along the first direction (X), and includes a first step portion (43), a connecting portion (44), and a second step portion (45) connected in sequence. The clamping wedge (40) has a push-pull hole (46) that runs through the first direction (X). The first step (43) and the second step (45) abut against the two ends of the clamping wedge (40) in the first direction (X). The connecting part (44) passes through the push-pull hole (46).

3. The clamp according to claim 2, characterized in that, There is a preset gap between the connecting part (44) and the inner wall of the push-pull hole (46).

4. The clamp according to claim 1, characterized in that, The fixture also includes a positioning sleeve (30), which is fitted and fixedly installed on the support shaft (10) and is spaced apart from all the expansion blocks (20) along the first direction (X).

5. The clamp according to claim 4, characterized in that, The positioning sleeve (30) is provided with a frustum (31), and the large diameter end of the frustum (31) is located on the side of the small diameter end away from the expansion block (20).

6. The clamp according to claim 4, characterized in that, The fixture also includes multiple adjusting components (33), and the positioning sleeve (30) is provided with multiple adjusting holes (32) around the axis of the support shaft (10), and each adjusting hole (32) is provided with a thread. All the adjusting members (33) are threadedly connected to all the adjusting holes (32), and each adjusting member (33) can abut against the support shaft (10) during the movement within the corresponding adjusting hole (32).

7. A machine tool, characterized in that, Includes the clamp as described in any one of claims 1-6.

8. A method for adjusting the coaxiality of a clamp, applicable to the support shaft (10) and the positioning sleeve (30) in the clamp as described in claim 6, characterized in that, Includes the following steps: With the dial indicator (60) fixed and the probe of the dial indicator (60) in contact with the side of the positioning sleeve (30), rotate the support shaft (10). Adjust the coaxiality of the positioning sleeve (30) and the clamping wedge (40) according to the fluctuation of the dial indicator (60).

9. The method for adjusting the coaxiality of the clamp according to claim 8, characterized in that, The steps for adjusting the coaxiality of the positioning sleeve (30) and the clamping wedge (40) specifically include: The coaxiality of the positioning sleeve (30) and the support shaft (10) is adjusted by at least one of the adjustment members (33) until the value of the dial indicator (60) meets the preset condition when the support shaft (10) rotates N times.

10. The method for adjusting the coaxiality of the clamp according to claim 8, characterized in that, Before adjusting the coaxiality of the positioning sleeve (30) and the support shaft (10) based on the fluctuation of the dial indicator (60) value, the method further includes the following steps: Adjust the position of at least one of the adjustment members (33) so that each of the adjustment members (33) contacts the support shaft (10).

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