A quick-change self-centering fixture for a numerical control lathe

Abstract

The application provides a quick-change self-centering clamp for a numerical control lathe, and relates to the technical field of numerical control lathe clamps, and comprises a semicircular base, a positioning disc, a clamping assembly, a driving assembly and the like, wherein the clamping assembly comprises a guide groove, a guide block, a mounting seat, a cross mounting groove, a cross mounting block, a clamping head and a mounting bolt; the driving assembly comprises a fixed shaft, a driving disc, an arc-shaped hole and a driving shaft. Through the embedded structure of the cross mounting groove and the cross mounting block, a single mounting bolt is adopted for locking, and the clamping head and the mounting seat are quickly disassembled and assembled without tools. When it is necessary to replace clamping heads with different shapes, only one mounting bolt needs to be loosened, the original cross mounting block is taken out upward from the cross mounting groove, the cross mounting block with a new clamping head is replaced, and the bolt is tightened, so that the replacement is completed. In the process, the guide block, the mounting seat and the like remain unchanged, and it is unnecessary to re-calibrate the centering reference, the auxiliary time of equipment shutdown is reduced, and the actual demand for quick replacement in multi-variety and small-batch production is met.

Description

Technical Field

[0001] This invention relates to the field of CNC lathe fixture technology, and more particularly to a quick-change self-centering fixture for CNC lathes. Background Technology

[0002] As the core main equipment for precision machining, CNC lathes rely on fixtures, which are the core tooling to ensure workpiece positioning accuracy, clamping stability and batch processing consistency. Their structural performance directly determines key accuracy indicators such as workpiece coaxiality, roundness and cylindricity, and also profoundly affects equipment changeover cycle time and overall production efficiency.

[0003] Existing CNC lathe fixtures have inherent structural defects in modern machining scenarios involving multiple varieties, small batches, and high precision, failing to meet the demands of high-end precision machining production. Firstly, the jaws and slides of traditional self-centering chucks are a fixed, integrated structure, with non-replaceable clamping contours and a limited range of styles, only suitable for clamping standard round workpieces. Secondly, traditional self-centering fixtures have poor transmission synchronization. Multiple sets of jaws have independent errors in radial movement. After long-term operation, wear of the transmission structure will further aggravate the problem of jaw synchronization offset, causing workpiece centering reference offset, machining coaxiality accuracy drift, and batch processing accuracy consistency cannot be guaranteed. Secondly, the existing clamps and clamp bodies are mostly bolt-fastened structures. When machining workpieces of different shapes, it is necessary to change the clamping structure to adapt to the new structure. Special tools such as wrenches and screwdrivers are required to disassemble the fastening bolts one by one, replace the clamps, and then recalibrate and tighten them. The replacement process is cumbersome and time-consuming. A single clamp replacement and alignment calibration usually takes several minutes, which greatly increases the downtime of the equipment and seriously affects the continuous machining efficiency of CNC lathes. It cannot meet the needs of rapid workpiece changeover production.

[0004] To address these issues, the present invention provides a quick-change self-centering fixture for CNC lathes. Summary of the Invention

[0005] To address the aforementioned technical problems, a quick-change self-centering fixture for CNC lathes is provided. This invention primarily solves the problems of cumbersome and time-consuming clamping head replacement operations, poor synchronicity of radial movement of multiple jaws, and easy drift in centering accuracy in existing CNC lathe fixtures through the interlocking and locking structure of the cross mounting block and cross mounting groove, and the synchronous radial movement mechanism driven by the drive disc and arc-shaped hole.

[0006] The technical means employed in this invention are as follows: A quick-change self-centering fixture for CNC lathes, comprising: Semi-circular base; The positioning plate is fixedly connected to the inner cavity of the semi-circular base; A clamping assembly is disposed on the surface of a positioning disk, including multiple guide grooves opened radially. The multiple guide grooves are arranged in a circular array on the surface of the positioning disk. A guide block is slidably connected to the inner cavity of the guide groove in the radial direction. A mounting base is fixedly connected to the top of the guide block. A cross mounting groove is opened on the top of the mounting base. A cross mounting block is disposed in the inner cavity of the cross mounting groove. A clamping head is fixedly connected to one side of the cross mounting block. A mounting bolt is passed through the top of the cross mounting block. The bottom of the mounting bolt is threadedly connected to the threaded groove at the bottom of the inner cavity of the cross mounting groove. A drive assembly, located at the bottom of the positioning disk, includes a fixed shaft. The top of the fixed shaft is fixedly connected to the bottom of the positioning disk. A drive disk is movably connected to the surface of the fixed shaft. The surface of the drive disk has a circular array of multiple arc-shaped holes. The inner cavity of each arc-shaped hole is movably connected to a drive shaft. The top of the drive shaft is fixedly connected to the bottom of a guide block.

[0007] Furthermore, a mounting platform is fixedly connected to one side of the semi-circular base, a rotating block is movably connected to the top of the mounting platform, an electric push rod is fixedly connected to one side of the rotating block, a drive block is fixedly connected to the telescopic shaft of the electric push rod, a drive plate is movably connected to the bottom of the drive block, a mounting shaft is fixedly connected to one side of the top of the drive plate, a side plate is movably connected to the surface of the mounting shaft, and one side of the side plate is fixedly connected to the edge of the drive disc surface.

[0008] Furthermore, a limiting ring is fixedly connected to the top of the mounting shaft surface, and the bottom of the limiting ring is fixedly connected to the top of the side plate.

[0009] Furthermore, a limiting ring is fixedly connected to the bottom edge of the positioning disk, and the inner wall of the limiting ring contacts the top edge of the drive disk surface.

[0010] Furthermore, limit strips are fixedly connected to both sides of the inner cavity of the guide groove, and limit grooves that cooperate with the limit strips are opened on both sides of the guide block.

[0011] Furthermore, the surface of the drive shaft is provided with rollers, and the side of the rollers away from the drive shaft contacts the inner wall of the arc-shaped hole.

[0012] Furthermore, a clamping pad is fixedly connected to the top of the surface of the mounting bolt, and the bottom of the clamping pad is in close contact with the top of the cross mounting block.

[0013] Furthermore, a semi-circular mounting plate is fixedly connected to the bottom of the outer surface of the semi-circular base, and mounting holes are arrayed on the surface of the semi-circular mounting plate.

[0014] Furthermore, a bottom groove is provided at the bottom of the semi-circular base, and a semi-circular anti-slip pad is fixedly connected to the inner cavity of the bottom groove.

[0015] Furthermore, a circular groove is provided at the center of the top of the positioning disk, and a circular pad is provided in the inner cavity of the circular groove.

[0016] Compared with the prior art, the present invention has the following advantages: 1. This invention achieves tool-free quick assembly and disassembly between the clamping head and the mounting base by setting a cross mounting groove and a cross mounting block interlocking structure and using a single mounting bolt for locking. When it is necessary to replace the clamping head with a different shape, only one mounting bolt needs to be loosened, the original cross mounting block is taken out of the cross mounting groove, and then the cross mounting block with the new clamping head is inserted and the bolt is tightened to complete the replacement. During this process, the main transmission components such as the guide block and the mounting base remain stationary, and there is no need to recalibrate the centering reference, which reduces the equipment downtime and meets the actual needs of multi-variety, small-batch production for quick changeover.

[0017] 2. This invention creates arc-shaped holes in a circular array on the surface of the drive disk, and connects each drive shaft to the corresponding arc-shaped hole and the bottom of the guide block simultaneously. When the drive disk rotates around the fixed axis, all the arc-shaped holes synchronously push their respective drive shafts to move radially. Combined with the linear guiding cooperation between the limit strip in the guide groove and the upper limit groove of the guide block, it ensures that the radial displacement of each clamping head is equal. This single rotary drive is transformed into a transmission method of multiple sets of linear synchronous motion, eliminating the cumulative error and centering offset problem caused by the independent movement of multiple sets of jaws in traditional fixtures. Even after long-term use, it can still maintain high centering repeatability accuracy, ensuring the consistency of coaxiality of batch processed workpieces. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of a quick-change self-centering fixture for CNC lathes according to the present invention.

[0020] Figure 2 This invention relates to a quick-change self-centering fixture for CNC lathes. Figure 1 A magnified view of a portion of point A in the middle.

[0021] Figure 3 This is a bottom view schematic diagram of a quick-change self-centering fixture for CNC lathes according to the present invention.

[0022] Figure 4This is a schematic diagram of the drive disk in a quick-change self-centering fixture for CNC lathes according to the present invention.

[0023] Figure 5 This is a schematic diagram of the bottom structure of the positioning plate in a quick-change self-centering fixture for CNC lathes according to the present invention.

[0024] Figure 6 This invention relates to a quick-change self-centering fixture for CNC lathes. Figure 5 A magnified view of a portion of point B in the middle.

[0025] Figure 7 This is a schematic diagram of the mounting base, guide block, and drive shaft in a quick-change self-centering fixture for CNC lathes according to the present invention.

[0026] In the diagram: 1. Semicircular base; 2. Positioning plate; 3. Clamping assembly; 4. Drive assembly; 301. Guide groove; 302. Guide block; 303. Mounting base; 304. Cross mounting groove; 305. Cross mounting block; 306. Clamping head; 307. Mounting bolt; 401. Fixed shaft; 402. Drive plate; 403. Arc-shaped hole; 404. Drive shaft; 5. Mounting platform; 6. Rotating block; 7. Electric push rod; 8. Drive block; 9. Drive plate; 10. Mounting shaft; 11. Side plate; 12. Roller. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0032] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0033] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0034] Example 1 This invention provides a quick-change self-centering fixture for CNC lathes, comprising a semi-circular base 1, a positioning disk 2 fixedly connected to the inner cavity of the semi-circular base 1, a clamping assembly 3 disposed on the surface of the positioning disk 2, and a driving assembly 4 disposed at the bottom of the positioning disk 2. The clamping assembly 3 includes a plurality of radially arranged guide grooves 301, which are arranged in a circular array on the surface of the positioning disk 2. A guide block 302 is slidably disposed radially in the inner cavity of each guide groove 301. A mounting base 303 is fixedly connected to the top of the guide block 302. A cross mounting groove 304 is provided on the top of the mounting base 303, and a cross mounting block 305 is disposed in the inner cavity of the cross mounting groove 304. A clamping head 306 matching the contour of the workpiece to be clamped is fixedly connected to one side of the mounting block 305. A mounting bolt 307 is connected through the top of the cross mounting block 305. The bottom of the mounting bolt 307 is threadedly connected to the threaded groove at the bottom of the inner cavity of the cross mounting groove 304. The drive assembly 4 includes a fixed shaft 401. The top of the fixed shaft 401 is fixedly connected to the bottom of the positioning disk 2. A drive disk 402 is movably connected to the surface of the fixed shaft 401. A plurality of arc-shaped holes 403 are opened in a circular array on the surface of the drive disk 402. A drive shaft 404 is movably connected to the inner cavity of each arc-shaped hole 403. The tops of the plurality of drive shafts 404 are fixedly connected to the bottoms of the plurality of guide blocks 302 respectively.

[0035] Specifically, the core structure of this fixture includes a semi-circular base 1, a positioning disk 2, a clamping assembly 3, and a driving assembly 4. The positioning disk 2 is fixedly connected to the inner cavity of the semi-circular base 1, serving as the supporting foundation for the overall structure. The workpiece is placed at the center of the upper surface of the positioning disk 2. The clamping assembly 3 is located on the upper surface of the positioning disk 2, used to directly contact and clamp the workpiece; the driving assembly 4 is located at the bottom of the positioning disk 2, providing synchronous driving force to the clamping assembly 3.

[0036] The clamping assembly 3 consists of multiple guide grooves 301, guide blocks 302, mounting bases 303, cross mounting grooves 304, cross mounting blocks 305, clamping heads 306, and mounting bolts 307. The multiple guide grooves 301 are radially arranged and distributed in a circular array on the surface of the positioning disk 2. Each guide groove 301 has a guide block 302 that can slide along it. The top of the guide block 302 is fixed with a mounting base 303. The top of the mounting base 303 has a cross mounting groove 304. The cross mounting block 305 is embedded in the cross mounting groove 304, and a clamping head 306 extends from one side of the cross mounting block 305 for direct contact with the workpiece. A mounting bolt 307 passes through the top of the cross-shaped mounting block 305. This bolt 307 connects to the threaded groove at the bottom of the cross-shaped mounting slot 304, thus firmly fixing the cross-shaped mounting block 305 to the mounting base 303. When it is necessary to replace the clamping head 306 with a different shape or material, simply loosen the mounting bolt 307, remove the cross-shaped mounting block 305, replace it with a cross-shaped mounting block 305 containing the new clamping head 306, and retighten the mounting bolt 307 to complete the replacement. This eliminates the need to disassemble the entire mounting base 303 or guide block 302, enabling quick replacement of the clamping head 306. A soft pad is provided on the end face of the clamping head 306 that contacts the workpiece to prevent damage to the workpiece surface.

[0037] The drive assembly 4 includes a fixed shaft 401, a drive disk 402, an arc-shaped hole 403, and a drive shaft 404. The top of the fixed shaft 401 is fixedly connected to the bottom of the positioning disk 2, and the drive disk 402 is fitted onto the fixed shaft 401 and can rotate around it. The surface of the drive disk 402 has multiple arc-shaped holes 403 arranged in a circular array, and a drive shaft 404 passes through each arc-shaped hole 403. The top of the drive shaft 404 passes upward through the clearance hole on the positioning disk 2 and is fixedly connected to the bottom of the corresponding guide block 302; the clearance hole is a through hole opened at the bottom of the guide groove 301 (or the corresponding thickness area of ​​the positioning disk 2) and is coaxially connected with the guide groove 301; the guide groove 301 provides radial guidance at the top and circumferential limitation, and the clearance hole provides an axial through channel at the bottom, together forming the cross-disk connection channel between the guide block 302 and the drive shaft 404. When the drive disk 402 rotates around the fixed shaft 401, the position of the arc-shaped hole 403 changes, and its inner wall pushes the drive shaft 404 to move radially. Since the drive shaft 404 is fixed to the guide block 302, the guide block 302 slides radially within the guide groove 301, thereby driving the mounting base 303 and the clamping head 306 to move radially synchronously, achieving centering clamping or releasing of the workpiece. This structure ensures the accuracy and consistency of centering by simultaneously driving all clamping heads 306 to move towards or away from the center with the same displacement through the rotation of one drive disk 402. The arc-shaped hole 403 is an eccentric arc-shaped guide groove, and its center of curvature does not coincide with the rotation center of the drive disk 402, realizing the conversion of rotational motion into radial linear motion. The specific curve parameters of the arc-shaped hole 403 can be conventionally designed according to the clamping stroke.

[0038] It should be noted that the self-centering fixture of this invention ensures that the centering reference does not drift and does not restrict the workpiece contour. For irregular workpieces, the irregularity of the workpiece surface can be compensated by replacing it with a non-circular clamping head that matches the contour of the workpiece. The radial displacement of the clamping heads 306 is consistent, but the actual effective distance from their contact contour to the center can be arbitrarily adjusted by the shape of the clamping head body, thus it can fully adapt to irregular surfaces. Moreover, during the clamping process, all clamping heads move synchronously, ensuring centering accuracy and force balance. For workpieces with cutouts, a support block or limiting block without clamping function can be installed at the corresponding position of the cutout (still using the cross mounting block 305 interlocking structure), which maintains the mechanical balance of the drive disk 402 and avoids interference.

[0039] Example 2 Based on Embodiment 1, a mounting platform 5 is fixedly connected to one side of the semi-circular base 1, a rotating block 6 is hinged to the top of the mounting platform 5, an electric push rod 7 is fixedly connected to one side of the rotating block 6, a drive block 8 is fixedly connected to the telescopic shaft of the electric push rod 7, a drive plate 9 is hinged to the bottom of the drive block 8, a mounting shaft 10 is fixedly connected to one side of the top of the drive plate 9, a side plate 11 is movably connected to the surface of the mounting shaft 10 (the mounting shaft 10 can be used as a pin, and the side plate 11 rotates on the surface of the mounting shaft 10), and one side of the side plate 11 is fixedly connected to the edge of the surface of the drive disk 402.

[0040] Specifically: When the telescopic shaft of the electric push rod 7 extends or retracts, it drives the drive block 8 to move, and the drive block 8 pushes the drive plate 9 to rotate around the mounting shaft 10. Since the drive plate 9 is fixedly connected to the drive disk 402 through the side plate 11, the swing of the drive plate 9 is converted into the rotational motion of the drive disk 402, thereby driving the drive shaft 404 to move radially through the arc-shaped hole 403, and finally realizing the synchronous opening and closing of the clamping assembly 3.

[0041] A limiting ring is fixedly connected to the top of the mounting shaft 10 surface. The bottom of the limiting ring is fixedly connected to the top of the side plate 11. The limiting ring axially limits the side plate 11 to prevent the side plate 11 from moving up and down on the mounting shaft 10, ensuring the relative position between the drive plate 9 and the drive disk 402 is stable, enhancing the axial stability of the drive assembly 4, and preventing the side plate 11 from coming off due to vibration or load changes.

[0042] A limiting ring is fixedly connected to the bottom edge of the positioning disk 2. The inner wall of the limiting ring contacts the top edge of the drive disk 402. The limiting ring is fixed to the bottom edge of the positioning disk 2, and its inner wall forms a close contact with the top edge of the outer edge of the drive disk 402. When the drive disk 402 rotates on the fixed shaft 401, the limiting ring applies radial constraint to the drive disk 402 to prevent radial displacement during rotation. At the same time, the limiting ring does not restrict the rotational freedom of the drive disk 402. The bottom of the fixed shaft 401 is designed as an annular pad, and the top is designed as a limiting ring. The drive disk 402 is locked between the annular pad and the limiting ring, and can rotate around the fixed shaft 401 without loosening.

[0043] Limiting strips are fixedly connected to both sides of the inner cavity of the guide groove 301. Limiting grooves that cooperate with the limiting strips are opened on both sides of the guide block 302. The limiting strips are embedded in the limiting grooves to guide the guide block 302 to move linearly along the guide groove 301, preventing the guide block 302 from deflecting or tilting during the movement, improving the radial movement accuracy of the clamping head 306, and ensuring that multiple sets of clamping heads 306 are synchronously centered.

[0044] A roller 12 is provided on the surface of the drive shaft 404. The side of the roller 12 away from the drive shaft 404 contacts the inner wall of the arc-shaped hole 403. When the drive disk 402 rotates, the inner wall of the arc-shaped hole 403 pushes the roller 12, and the roller 12 drives the drive shaft 404 to move radially. The roller 12 converts sliding friction into rolling friction, reduces the frictional resistance between the drive shaft 404 and the arc-shaped hole 403, and makes the transmission smoother.

[0045] A clamping pad is fixedly connected to the top of the mounting bolt 307. The bottom of the clamping pad is in close contact with the top of the cross mounting block 305. When the mounting bolt 307 is tightened, the clamping pad applies pressure evenly to the upper surface of the cross mounting block 305 to prevent the mounting bolt 307 from loosening, enhance the connection reliability between the cross mounting block 305 and the cross mounting groove 304, and prevent the clamping head 306 from loosening during processing.

[0046] A semi-circular mounting plate is fixedly connected to the bottom of the outer surface of the semi-circular base 1. The surface of the semi-circular mounting plate is provided with mounting holes. The fixture is fixed to the spindle or worktable of the CNC lathe by bolts through the mounting holes. The semi-circular mounting plate provides a standardized installation interface, which facilitates quick installation and removal of the fixture. The semi-circular structure saves space and is suitable for compact lathe structures.

[0047] The bottom of the semi-circular base 1 has a bottom groove, and a semi-circular anti-slip pad is fixedly connected to the inner cavity of the bottom groove. The anti-slip pad is in direct contact with the lathe mounting surface. Its high coefficient of friction prevents the fixture from sliding or rotating during use, thereby improving the installation stability of the fixture, which is especially important during high-speed cutting or intermittent cutting.

[0048] A circular groove is formed at the center of the top of the positioning disk 2, and a circular pad is placed inside the cavity of the groove. The circular pad is installed in the circular groove on the top of the positioning disk 2, and its top surface is slightly higher than the surface of the positioning disk 2; its function is divided into two stages: Anti-slip effect when initially placing the workpiece: When the operator initially places the workpiece on the fixture, the annular pad provides a certain frictional resistance to prevent the workpiece from sliding or rotating randomly due to tilting, vibration or human touch when it is not clamped, which facilitates the subsequent centering and clamping operation of the clamping head 306. The supporting effect after clamping: After the clamping assembly 3 radially centers and clamps the workpiece, the annular pad provides elastic or flexible support to the central area of ​​the workpiece, preventing the workpiece from deforming due to its own weight or clamping force. This is especially suitable for thin-walled or machined workpieces.

[0049] The working principle of this invention is as follows: Align the semi-circular anti-slip pad at the bottom of the semi-circular base 1 with the mounting surface of the lathe spindle or worktable, and use bolts to pass through the mounting holes on the semi-circular mounting plate to fix and lock the fixture body on the machine tool.

[0050] Select the appropriate clamping head 306 according to the shape of the workpiece to be processed, such as round, square, or irregular. Loosen the mounting bolt 307, remove the original clamping head 306, replace it with a new clamping head 306, and tighten the mounting bolt 307.

[0051] The workpiece to be processed is roughly placed on the annular pad in the center of the positioning plate 2. The annular pad provides a certain amount of friction to prevent the workpiece from sliding freely.

[0052] Start the electric push rod 7 and control its telescopic shaft to extend. Through the transmission of the drive plate 9 and the drive disk 402, drive all the clamping heads 306 to move radially towards the center in sync until the clamping heads 306 are in close contact with the workpiece surface and the set clamping force is reached, then the electric push rod 7 stops moving.

[0053] Start the CNC lathe and perform turning operations on the centered and clamped workpiece.

[0054] After machining is completed, the telescopic shaft of the electric push rod 7 retracts, driving all the clamping heads 306 to move radially outward in sync, releasing the workpiece. The machined workpiece can then be removed from the fixture.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quick-change self-centering fixture for CNC lathes, characterized in that, include: Semicircular base (1); The positioning plate (2) is fixedly connected to the inner cavity of the semi-circular base (1); A clamping assembly (3) is disposed on the surface of a positioning disk (2) and includes multiple guide grooves (301) opened radially. The multiple guide grooves (301) are arranged in a circular array on the surface of the positioning disk (2). A guide block (302) is slidably connected to the inner cavity of the guide groove (301) in the radial direction. A mounting base (303) is fixedly connected to the top of the guide block (302). A cross mounting groove (304) is opened on the top of the mounting base (303). A cross mounting block (305) is disposed in the inner cavity of the cross mounting groove (304). A clamping head (306) is fixedly connected to one side of the cross mounting block (305). A mounting bolt (307) is connected through the top of the cross mounting block (305). The bottom of the mounting bolt (307) is threadedly connected to the threaded groove at the bottom of the inner cavity of the cross mounting groove (304). The drive assembly (4) is located at the bottom of the positioning disk (2) and includes a fixed shaft (401). The top of the fixed shaft (401) is fixedly connected to the bottom of the positioning disk (2). A drive disk (402) is movably connected to the surface of the fixed shaft (401). A plurality of arc-shaped holes (403) are opened in a circular array on the surface of the drive disk (402). A drive shaft (404) is movably connected to the inner cavity of the arc-shaped holes (403). The top of the drive shaft (404) is fixedly connected to the bottom of the guide block (302).

2. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, A mounting platform (5) is fixedly connected to one side of the semi-circular base (1). A rotating block (6) is movably connected to the top of the mounting platform (5). An electric push rod (7) is fixedly connected to one side of the rotating block (6). A drive block (8) is fixedly connected to the telescopic shaft of the electric push rod (7). A drive plate (9) is movably connected to the bottom of the drive block (8). A mounting shaft (10) is fixedly connected to one side of the top of the drive plate (9). A side plate (11) is movably connected to the surface of the mounting shaft (10). One side of the side plate (11) is fixedly connected to the edge of the drive disk (402).

3. The quick-change self-centering fixture for CNC lathes according to claim 2, characterized in that, A limiting ring is fixedly connected to the top of the surface of the mounting shaft (10), and the bottom of the limiting ring is fixedly connected to the top of the side plate (11).

4. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, A limiting ring is fixedly connected to the bottom edge of the positioning disk (2), and the inner wall of the limiting ring contacts the top edge of the drive disk (402) surface.

5. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, Limiting strips are fixedly connected to both sides of the inner cavity of the guide groove (301), and limiting grooves that cooperate with the limiting strips are opened on both sides of the guide block (302).

6. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, The surface of the drive shaft (404) is provided with a roller (12), and the side of the roller (12) away from the drive shaft (404) contacts the inner wall of the arc-shaped hole (403).

7. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, A pressure pad is fixedly connected to the top of the surface of the mounting bolt (307), and the bottom of the pressure pad is in close contact with the top of the cross mounting block (305).

8. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, The bottom of the outer surface of the semi-circular base (1) is fixedly connected to a semi-circular mounting plate, and the surface of the semi-circular mounting plate is provided with mounting holes.

9. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, The bottom of the semi-circular base (1) is provided with a bottom groove, and a semi-circular anti-slip pad is fixedly connected to the inner cavity of the bottom groove.

10. The quick-change self-centering fixture for CNC lathes according to claim 1, characterized in that, The positioning disk (2) has a circular groove at the center of its top, and a circular pad is provided in the inner cavity of the circular groove.

Images