Self-centering adjustable machining clamping device and clamping method

Abstract

The application discloses a self-centering adjustable machining clamping device, which comprises a clamping body, the clamping body comprises an assembly base, a floating platform is formed on the assembly base, an electric control lifting seat and a clamping part are assembled through the floating platform, the clamping part comprises a back frame, a rotating seat is assembled on the front side of the back frame, a driving frame is assembled on the rotating seat, and a multi-jaw chuck mechanism is assembled on the driving frame; the movable jaw of the multi-jaw chuck mechanism is L-shaped as a whole, is provided with a pressing block and an outwardly expanding inclined surface, a threaded top block is movably assembled on the outwardly expanding inclined surface, the threaded top block is provided with a pressing inclined surface, and the pressing inclined surface is intermittently formed with a contraction groove and a pressing pad block; and a workpiece clamping method based on the clamping device is further disclosed.The application has the advantages of good adaptability and high reliability, can effectively improve the production efficiency of specific pipe shaft workpieces, guarantee machining quality, reduce labor cost and improve safety.

Description

Technical Field

[0001] This invention relates to the field of workpiece clamping technology, specifically to a self-centering adjustable machining clamping device and clamping method. Background Technology

[0002] Self-centering fixtures are a commonly used type of machining auxiliary tool, applicable to various machining fields such as lathes, milling machines, and grinding machines. They primarily utilize the outer or inner diameter of the workpiece for positioning, achieving automatic centering and clamping through an internal mechanism. They can automatically center and clamp the workpiece to be machined, ensuring its stability and preventing deformation during processing. This effectively reduces human error and improves machining accuracy and production efficiency.

[0003] There are various types of self-centering chucks in the existing technology, such as the common multi-jaw chuck mechanism, which includes three-jaw chucks and four-jaw chucks. As a structural accessory of machine tools, it is often used in general positioning machining equipment such as lathes and welding machines. It is relatively convenient to use. The workpiece is simply placed in the chuck, and then the multiple movable jaws evenly distributed on the chuck body are driven to move radially by a handle or by pneumatic or hydraulic drive. The guide part of the jaws is provided with a threaded surface, which meshes with the flat thread on the back of the disc bevel gear. When driven by external force, the disc bevel gear in the chuck body is rotated, so that the flat thread on the back simultaneously drives the movable jaws to move equidistantly towards the center of the chuck, so as to achieve workpiece clamping and positioning. In the clamping state, it has the advantages of uniform clamping force distribution, good clamping stability, and simple operation.

[0004] However, under current technological conditions, the drawbacks of this type of multi-jaw chuck mechanism are insufficient precision and limited applicability:

[0005] In terms of precision, when a multi-jaw chuck mechanism uses movable jaws to clamp and fix the workpiece on the chuck body, it is mostly a circumferential line clamping on a single ring surface. Affected by factors such as workpiece surface roughness, uneven placement, and clamping clearance of the chuck mechanism, it is easy to cause inaccurate clamping position or slight radial movement during the rotation of the chuck, which will reduce the machining accuracy to a certain extent.

[0006] Regarding its applicability, chucks are primarily suitable for end face machining or surface machining on inner and outer diameters of straight shafts or straight tubes with small diameters and lengths. This does not meet the following requirements:

[0007] I. Machining requirements for the above-mentioned end face machining or inner and outer diameter upper surface machining of complex tubular and shaft-like workpieces with bending structures;

[0008] Second, it cannot meet the oblique machining requirements on the end face of straight shaft or straight tube workpieces, as well as complex tube and shaft workpieces with bending structures.

[0009] Third, for straight shaft or straight tube workpieces with a certain length, the clamping effect of the multi-jaw chuck mechanism is unstable due to the self-weight of the outer end of the workpiece and the plasticity of the workpiece material. It cannot meet the clamping requirements and may cause the outer end of the workpiece to bend and deform, resulting in great processing difficulty.

[0010] In addition, existing multi-jaw chuck mechanisms are mostly fixed in position on the machine tool. After assembly, they can only perform surface machining operations by axial extension and retraction in the assembly part, which has certain limitations in the field of machining.

[0011] For the reasons mentioned above, it is necessary to design a self-centering fixture that can be applied to machine tools, is easy to operate, is suitable for tubular and shaft workpieces with bending structures or long dimensions, and has adjustable position and angle to support machining operations on machine tools, thereby improving the accuracy and efficiency of machining and reducing human error and labor intensity. Summary of the Invention

[0012] The technical problem solved by the present invention is to provide a self-centering adjustable machining clamping device and clamping method, which can overcome the shortcomings in the above-mentioned background art.

[0013] The technical problem solved by this invention is achieved by the following technical solution:

[0014] A self-centering adjustable machining clamping device includes a clamping body, the clamping body including an assembly base, the assembly base having an assembly part formed on its bottom surface for integral forming with a machine tool, the assembly base having a floating platform formed on the assembly base that can move in a horizontal plane and maintain its position; an electrically controlled lifting seat is provided on the floating platform, and the clamping part is assembled through the electrically controlled lifting seat.

[0015] The clamping part includes a back frame, which is assembled with the electrically controlled lifting seat through the back frame and can be vertically adjusted through the electrically controlled lifting seat. The back frame is equipped with a rotary table on the front side. The rotation plane of the rotary table is perpendicular to the movement plane of the floating platform and parallel to the feed direction of the machine tool head. The rotary table is equipped with a drive frame, and the drive frame is equipped with a multi-jaw chuck mechanism. The drive frame can drive the multi-jaw chuck mechanism to rotate.

[0016] The multi-jaw chuck mechanism includes a chuck body with a through hole extending from its axis. Multiple synchronously feeding movable jaws are arranged on the outer circumferential surface of the through hole. Each movable jaw is L-shaped, with a guide thread surface on its first right-angled side that matches the disc bevel gear in the chuck body, and its second right-angled side located on one side of the through hole. A pressure block is formed at one end of the second right-angled side on the through hole side. This pressure block clamps onto the workpiece surface when the movable jaw moves centripetally. The other end of the second right-angled side on the through hole side... The end is formed with an outwardly expanding inclined surface, and a threaded top block is movably mounted on the outwardly expanding inclined surface. The threaded top block is an end face ring structure that matches the through hole. The end face ring structure has a clamping inclined surface that matches the outwardly expanding inclined surface. The ring surface corresponding to the clamping inclined surface is formed with shrinkage grooves at intervals. On the inner side of the ring surface corresponding to the through hole, clamping pads are formed at intervals. The threaded top block can be screwed onto the movable jaw from the outwardly expanding inclined surface side, and by continuously tightening the threaded top block, the clamping pads are clamped to the surface of the workpiece.

[0017] As a further limitation, the assembly part is one or a combination of plug-in assembly structure, snap-fit ​​assembly structure, welded assembly structure, and threaded assembly structure.

[0018] As a further limitation, the floating platform is mounted on the mounting base via a combination guide rail and can move in position via the combination guide rail; the combination guide rail includes a pair of first guide rails and a pair of second guide rails, the guiding directions of the first guide rails and the second guide rails being perpendicular to each other; the floating platform is mounted on the first guide rails at both ends, and the first guide rails are equipped with end sliders at both ends, and are mounted on the second guide rails via the end sliders;

[0019] The movement of the end slider of the first guide rail on the guide rail lead and the movement of the floating platform on the guide rail lead are both achieved by the drive motor, and the position can be maintained by the drive motor.

[0020] As a further limitation, the rotation angle of the rotary seat can be adjusted manually or electrically using one of the following mechanisms: a screw mechanism, a worm gear mechanism, a ball screw mechanism, or a harmonic gear mechanism.

[0021] As a further limitation, the multi-jaw chuck mechanism is detachably mounted on the drive frame. By disassembling and replacing multi-jaw chuck mechanisms of different sizes, workpieces of different sizes can be replaced.

[0022] It also includes a non-axis workpiece assembly base, which can replace the multi-jaw chuck mechanism on the drive frame after the multi-jaw chuck mechanism is removed, so as to realize the clamping of the non-axis workpiece and subsequent processing operations.

[0023] As a further limitation, the distance between the pressure block and the clamping pad is 1 to 5 times the outer diameter of the workpiece to be processed.

[0024] As a further limitation, the contact surfaces of the pressure block and the clamping pad with the workpiece on the through hole side are toothed contact surfaces.

[0025] As a further limitation, it also includes a second fixing part, which is disposed on the opposite side of the clamping body relative to the machine tool head. The second fixing part is a half-joint clamping structure that matches the outer diameter of the workpiece to be processed. The second fixing part is a detachable structure and is connected to the clamping body by an adjustable rigid frame or rigid connecting rod.

[0026] As a further limitation, the threaded top block is provided with a torque amplification device to assist the threaded top block in the screwing operation at the outer end of the movable jaw.

[0027] This invention also provides a workpiece clamping method, which uses a self-centering adjustable machining clamping device to fix and clamp tubular and shaft-type workpieces on a machine tool, and can cooperate with the machine tool head to perform machining operations. The specific operation steps are as follows:

[0028] S1 uses the assembly section to perform fixed assembly on the machine tool and reserves the moving space of the floating platform; then selects the matching multi-jaw chuck mechanism and threaded top block according to the outer diameter of the workpiece, and completes the assembly of the multi-jaw chuck mechanism on the drive frame of the assembly base.

[0029] S2 uses a rotary table to adjust the machining angle of the multi-jaw chuck mechanism, and then sequentially positions and calibrates the multi-jaw chuck mechanism on the floating table and the electrically controlled lifting table, and sets the zero position.

[0030] S3 completes the clamping of the workpiece on the multi-jaw chuck mechanism, and completes the self-centering calibration clamping of the workpiece by using the clamping operation of the multi-jaw chuck mechanism. Then, the outer end of the movable jaw of the multi-jaw chuck mechanism is pressed by the threaded top block. Then, the workpiece is clamped in two stages by the pressure block and the pressure pad on the inner side of the movable jaw.

[0031] In the S4 machining process, the axial direction of the workpiece clamped on the multi-jaw chuck mechanism is taken as the X-axis, the horizontal radial direction of the workpiece clamped on the multi-jaw chuck mechanism is taken as the Y-axis, and the vertical direction is taken as the Z-axis. Then:

[0032] The position of the workpiece in the XY plane is adjusted using a floating platform;

[0033] The position of the workpiece on the Z-axis is adjusted using an electrically controlled lifting platform.

[0034] Adjust the tilt angle of the workpiece in the YZ plane using a rotary table;

[0035] The rotation and speed of the multi-jaw chuck mechanism are controlled by the drive frame, which works in conjunction with the machine tool head to perform machining operations.

[0036] As a further limitation, in step S1, the clamping and machining of non-axis workpieces can be achieved by replacing the multi-jaw chuck mechanism with a non-axis workpiece assembly seat.

[0037] As a further limitation, when the workpiece is clamped in step S1, if the workpiece has a long dimension or a bent structure that affects the outer end deflection, the second fixing part is used for auxiliary clamping, and after the clamping is stable, the second fixing part is rigidly connected to the clamping body and held by an adjustable rigid frame or rigid connecting rod.

[0038] Beneficial effects: The self-centering adjustable machining clamping device of the present invention has a compact structure and reasonable design. It uses an improved multi-jaw chuck mechanism to clamp the workpiece in the middle section, which makes the workpiece loading and unloading convenient and can achieve self-centering, thereby improving machining accuracy. The structure is reliable and can ensure the orientation and position of the machined surface.

[0039] The device is highly adaptable to workpieces with tubular or shaft-like structures, and can accommodate different workpiece shapes, sizes, and materials. It can stably clamp the workpiece, ensuring that the workpiece remains in a stable position during processing and preventing loss of processing accuracy due to workpiece displacement, thereby guaranteeing processing quality.

[0040] The device is reasonably designed and, in conjunction with the corresponding workpiece clamping method, can quickly adjust the position of the workpiece. It has a high degree of freedom and good stability in adjustment, and can reduce reliance on manual operation, reduce labor costs, reduce operational risks, and improve the safety of operation during machining. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the assembly structure of a preferred embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of the combined guide rail according to a preferred embodiment of the present invention.

[0043] Figure 3 This is a structural diagram of the movable claw in a preferred embodiment of the present invention.

[0044] The components are as follows: 1. Machine tool; 2. Assembly section; 3. Fixing frame; 4. Workpiece; 5. Second fixing section; 6. Top frame; 7. Lifting guide rail; 8. Electrically controlled lifting seat; 9. Machine tool head; 10. Head base; 11. Head guide rail; 12. Assembly base; 13. Protective cover; 14. Rotary seat; 15. Floating platform; 16. Drive frame; 17. Multi-jaw chuck mechanism; 18. Back frame; 19. End slider; 20. First guide rail; 21. Second guide rail; 22. Movable jaw; 23. Guide thread surface; 24. Movable jaw; 25. Pressure block; 26. Threaded thread surface; 27. Threaded top block embedding part; 28. Pressure pad; 29. ​​Threaded top block body; 30. Torque amplification device. Detailed Implementation

[0045] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0046] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0047] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in an embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Furthermore, in the embodiments of the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0048] In addition, in the embodiments of the present invention, if the connection of components is involved, unless otherwise specified in this specific embodiment, the connection method of similar structures on the market can be referred to for connection, as long as the corresponding connection effect can be achieved.

[0049] See Figures 1-3 A preferred embodiment of a self-centering adjustable machining clamping device is provided. In this embodiment, the clamping device is used to clamp the workpiece 4 and then perform end face machining using the machine tool head 9 of the machine tool 1. The workpiece 4 is a section of bent tube shaft with an overall "L" shape. The clamping device is used to maintain stable clamping of the workpiece 4 in subsequent machining processes after self-centering clamping, and can maintain multi-degree-of-freedom feed and adjustment.

[0050] The clamping device includes an assembly base 12 as the main support structure. The assembly base 12 has a stepped assembly section on its bottom surface that matches the machine tool 1. This stepped assembly section allows for placement and leveling within the machining area of ​​the machine tool 1. An assembly section 2 is provided on the outer side of the assembly base 12 via ear plates. The clamping device uses countersunk bolts to integrally assemble the assembly base 12 with the machine tool 1 at this assembly section 2. Correspondingly, the machine tool 1 has a machine head 9 on its right side. The machine head 9 is equipped with a tool post and is mounted on a headstock base 10. The headstock base 10 is equipped with two sets of drive motors. One set of drive motors drives the machine head 9 to rotate, cooperating with different machining tools mounted on the tool post to perform corresponding machining operations. Simultaneously, the lower part of the headstock base 10 is mounted on a headstock guide rail 11. The other set of motors in the headstock base 10 drives the entire headstock base 10, causing the machine head 9 to move slightly along the headstock guide rail 11 to meet the needs of the machining operations.

[0051] The assembly base 12 has a floating platform 15 on its upper surface. Using the horizontal plane corresponding to the assembly base 12 as the XY plane, the floating platform 15 can move within this XY plane (parallel) and maintain its position at any selected location after movement. To achieve this function, the floating platform 15 is positioned as follows: Figure 2 The combined guide rail shown is mounted on the mounting base 12. The combined guide rail includes a pair of first guide rails 20 and a pair of second guide rails 21. The orientation of the first guide rails 20 and the second guide rails 21 corresponds to the feed direction and retraction direction of the machine tool head 9, while the orientation of the second guide rails 21 is perpendicular to the orientation of the first guide rails 20. The bottom surface of the float 15 is provided with a slide block and is mounted on the first guide rail 20 through the slide block. Through the slide block, the float 15 can slide along the X-axis on the lead of the first guide rail 20. The two ends of the first guide rail 20 are equipped with end sliders 19, which are mounted on the second guide rail 21 and enable the float 15 connected to the first guide rail 20 to slide along the Y-axis on the lead of the second guide rail 21.

[0052] As the power source for movement, the drive motor for moving the floating platform 15 on the first guide rail 20 is mounted on the back side of the floating platform 15, while the drive motor for moving the end slider 19 on the second guide rail 21 is mounted at the end slider 19. By using the corresponding drive motor stop positions, the floating platform 15 can be suspended at a selected position on the corresponding XY plane, so as to facilitate the machine tool head 9 to perform selected position machining operations on the workpiece 4.

[0053] Considering the potential interference from debris generated during machining operations, the combined guide rail is protected on the top and sides by a protective cover 13.

[0054] In this embodiment, the surface of the floating platform 15 is formed with an electrically controlled lifting seat 8. The main body of the electrically controlled lifting seat 8 is a rigid support. The rigid support is structurally reinforced on the back side by a back rib plate. Two sets of lifting guide rails 7 are longitudinally arranged on the electrically controlled lifting seat 8. The top of the electrically controlled lifting seat 8 is closed by a top frame 6 and serves as the upper limit structure of the lifting guide rails 7.

[0055] The main body of the back frame 18 is a plate structure. Its back side is mounted on the lifting guide rail 7 through the mounting base, so that the back frame 18 can be raised and lowered on the electrically controlled lifting seat 8 through the combination of the lifting guide rail 7 and the drive motor, thereby driving the back frame 18 to move on the Z axis in the corresponding machine tool coordinate system.

[0056] The back frame 18 has a rotating base 14 formed on its front side. A drive frame 16 is mounted on the rotating base 14. The main body of the drive frame 16 is an electrically controlled rotating frame structure, in which a multi-jaw chuck mechanism 17 is mounted. The electrically controlled rotating frame structure of the drive frame 16 can drive the multi-jaw chuck mechanism 17 to rotate, so that the multi-jaw chuck mechanism 17 can achieve the rotational shape of a multi-jaw chuck mechanism 17 on a traditional machine tool, facilitating corresponding machining operations with the machining tools mounted on the machine tool head 9. The rotating base 14 allows the axis of the drive frame 16 to be adjusted at an angle relative to the X-axis in the YZ plane. The function of the rotating base 14 is to rotate the structure mounted on it around the axis of the rotating base 14, so as to achieve the angled clamping of the workpiece 4 by the multi-jaw chuck mechanism 17 to meet the machining requirements of the corresponding angle of the workpiece 4; for example, in Figure 1 In the embodiment shown, the multi-jaw chuck mechanism 17 is rotated by the rotary table 14 at a 5° elevation angle to be processed.

[0057] To ensure the accuracy and stability of the rotation angle adjustment of the rotary seat 14, in different embodiments, the rotation angle adjustment of the rotary seat 14 is carried out manually or electrically through one of the following mechanisms: screw mechanism, worm gear mechanism, ball screw mechanism, and harmonic gear mechanism. In this embodiment, an electrically controlled ball screw mechanism is selected to balance structural cost and performance.

[0058] In this embodiment, the multi-jaw chuck mechanism 17 is an improved four-jaw chuck mechanism, wherein four movable jaws 24 are evenly arranged on the outer circumference of the chuck body, the included angle between adjacent movable jaws 24 is 90°, and a corresponding insertion hole for mounting the workpiece 4 is provided on the chuck body at the center of the four movable jaws 24. The structural style of the four movable jaws 24 corresponding to the insertion holes on the outer circumference of the chuck body is as follows: Figure 3As shown: The overall structure of the movable jaw 24 is L-shaped, with the vertical side of the L-shape being the first right angle side. A guide thread surface 23 is formed on its back side. This guide thread surface 23 meshes with the disc bevel gear in the chuck body. This part of the structure is similar to the four-jaw chuck transmission structure commonly used in the prior art. When driven by an external force, the disc bevel gear in the chuck body is rotated, causing the guide thread surface 23 on the back side of the guide thread surface 23 to move simultaneously, thereby driving the movable jaw 24 to move equidistantly relative to the center of the chuck, so as to achieve the clamping and positioning of the workpiece 4.

[0059] As an improved structure, the multi-jaw chuck mechanism 17 of this embodiment differs from the four-jaw chuck in the design of the movable jaw 24. The horizontal side of the movable jaw 24 is a second right-angled side, and a pressure block 25 is formed at the base of the movable jaw 24 on the second right-angled side. The pressure block 25 can press against the surface of the workpiece 4 while the movable jaw 24 moves centripetally to achieve one-time clamping and self-centering positioning. An outwardly expanding inclined surface is formed on the outer side of the movable jaw 24 on the second right-angled side, and a threaded surface is formed on the outwardly expanding inclined surface. The structure matching the threaded surface is a threaded top block. The threaded top block, as a fastening consumable, has an end face ring structure that matches the through hole on the chuck body. The annular cross-section of the threaded top block includes a threaded top block body 29 located on the outer side. The back side and outer annular surface of the threaded top block body 29 are formed with reinforced ear plates as torque amplification devices 30. The face side of the threaded top block body 29 is formed with a threaded top block insert. The outer surface of the threaded top block insert has A clamping slope is matched with the outward expansion slope on the movable jaw 24. The slope of the clamping slope is the same as that of the outward expansion slope, and it has a threaded surface 26 that matches the threaded surface on the outward expansion slope. A shrinkage groove (similar to the opening structure on the expansion bolt sleeve) is formed at intervals on the annular surface corresponding to the clamping slope. In addition, a clamping pad 28 is provided at the position of the misaligned shrinkage groove on the inner side of the threaded top block embedding part 27. The clamping pad 28 is spaced apart from the pressure block 25, and the distance between the clamping pad 28 and the pressure block 25 is 1 to 5 times the outer diameter of the workpiece 4 to be processed.

[0060] The self-centering adjustable machining clamping device of this embodiment can be used to assist in clamping and fixing conventional tube and shaft workpieces on machine tool 1, and can cooperate with the machine tool head to perform machining operations. It is also suitable for clamping and fixing tube and shaft workpieces with bending structures or long dimensions on machine tool 1, and can cooperate with the machine tool head to perform machining operations.

[0061] For example Figure 1 Taking the tubular shaft workpiece 4 with a bending structure as an example, the clamping operation is performed as follows:

[0062] First, a machining position is cleared on the machine tool 1, and the assembly base 12 is fixedly assembled on the machine tool using the assembly part 2, leaving room for the floating platform 15 to move. Then, a matching multi-jaw chuck mechanism 17 and a corresponding threaded top block are selected according to the outer diameter of the workpiece, and the multi-jaw chuck mechanism 17 is assembled on the drive frame of the assembly base 12.

[0063] The machining angle of the multi-jaw chuck mechanism 17 is adjusted by using a rotary table. Then, the multi-jaw chuck mechanism 17 is positioned and calibrated on the floating table 15 and the electrically controlled lifting seat 8 in sequence, and the zero position is set.

[0064] The workpiece 4 is assembled on the multi-jaw chuck mechanism 17. During assembly, the end of the workpiece 4 to be processed is passed through the through hole on the multi-jaw chuck mechanism 17 from left to right, and a processing space is left at the right end of the through hole. The movable jaw 24 on the multi-jaw chuck mechanism 17 is controlled to move centripetally, and the pressure block 25 on the inner base of the movable jaw 24 is used to pre-fix and clamp the surface of the workpiece 4. Then, the threaded top block is screwed into the open end on the right side of the movable jaw 24 with the help of external force using the torque amplification device 30. During the screwing process, the threaded top block is compressed and retracted by deforming at the shrinkage groove position of the clamping slope, and the clamping pad 28 is continuously pressed against the workpiece 4. The two-stage clamping and fixing of the double ring surface is achieved through the cooperation of the pressure block 25 and the clamping pad 28, thereby maintaining the clamping stability of the workpiece, thus completing the clamping.

[0065] During the machining process, the multi-jaw chuck mechanism 17 is used as a reference for the spatial axis system of the machine tool 1: the floating table 15 is used to adjust the position of the workpiece 4 in the XY plane; the electric lifting seat 8 is used to adjust the position of the workpiece 4 on the Z axis; the rotary table 14 is used to adjust the tilt angle of the workpiece 4 in the YZ plane; the drive frame 16 is used to control the rotation and speed of the multi-jaw chuck mechanism 17, thereby controlling the rotation and machining speed of the workpiece 4; the machine tool head 9 and the head base 10 are used to control the rotation and feed action of the machining tool.

[0066] After machining is completed and the tool is retracted, the movable jaw 24 is first removed from the multi-jaw chuck mechanism 17, and then the threaded top block is removed using the torque amplification device 30, so that the machined workpiece 4 can be taken out.

[0067] In this embodiment, to optimize the clamping effect of the pressure block 25 and the clamping pad 28 on the workpiece 4, the contact surfaces of the pressure block 25 and the clamping pad 28 with the workpiece on the through hole side can be set as toothed contact surfaces. When the workpiece has a long dimension or a bent structure that affects the outer end deflection, a matching second fixing part 5 is also included on the back frame 18, such as for clamping. Figure 1When the workpiece 4 with the L-shaped bending structure is shown, the second fixing part 5 is a half-joint clamping structure that matches the outer diameter of the workpiece to be processed. The outer side of the second fixing part 5 is connected to the fixing frame 3 through the connecting part. The back side of the fixing frame 3 is rigidly connected to the back frame 18 through an adjustable rigid frame or rigid connecting rod, so as to maintain the position structure fixed when the outer end of the workpiece 4 is easily affected.

[0068] In other embodiments, the clamping and processing of non-axis workpieces can also be achieved by replacing the multi-jaw chuck mechanism 17 with a non-axis workpiece assembly seat. Under this technical condition, the multi-jaw chuck mechanism 17 is first removed from the drive frame 16, and then the non-axis workpiece assembly seat that matches the drive frame 16 is replaced. This allows for clamping and subsequent processing of non-axis workpieces in a similar assembly manner.

[0069] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A self-centering adjustable machine tool clamping device, characterized by, The clamping body comprises an assembly base, which is formed with an assembly part on the bottom surface for being formed integrally with the machine tool, and a floating platform formed on the assembly base and capable of moving in the horizontal plane and being position-kept; an electric control lifting seat is arranged on the floating platform, and a clamping part is assembled with the electric control lifting seat; The clamping part comprises a back frame, which is assembled integrally with the electric control lifting seat and capable of being vertically adjusted by the electric control lifting seat, and a rotating seat assembled on the front side of the back frame, wherein the rotating plane of the rotating seat is perpendicular to the moving plane of the floating platform and parallel to the tool head feed direction of the machine tool, a driving frame is assembled on the rotating seat, and a multi-jaw chuck mechanism is assembled on the driving frame and capable of being driven to rotate by the driving frame; The multi-jaw chuck mechanism comprises a chuck body, a through hole passing through the chuck body is arranged on the chuck body, a plurality of movable jaws are arranged on the outer ring surface of the through hole of the chuck body and capable of being synchronously fed, each movable jaw is L-shaped, a guide threaded surface matched with a bevel gear in the chuck body is arranged on the first right-angle side of the L-shaped movable jaw, and the second right-angle side is located on one side of the through hole; a pressing block is formed on one end of the second right-angle side on the side of the through hole, the pressing block is clamped to the surface of a workpiece when the movable jaw moves towards the center, an outwardly expanding inclined surface is formed on the other end of the second right-angle side on the side of the through hole, a threaded top block is movably assembled on the outwardly expanding inclined surface, the threaded top block is an end face ring sleeve structure matched with the through hole, the end face ring sleeve structure has a pressing inclined surface matched with the outwardly expanding inclined surface, a plurality of contraction grooves are formed on the corresponding ring surface of the pressing inclined surface, and a plurality of pressing pads are arranged on the inner side of the ring surface corresponding to the through hole; 2. The self-centering adjustable machine chucking device of claim 1, wherein, The assembly part is one of or a combination of a plug-in assembly structure, a clamping assembly structure, a welding assembly structure and a threaded assembly structure.

3. The self-centering adjustable machine chucking device of claim 1, wherein, The floating platform is assembled on the assembly base by a combined guide rail and capable of moving by the combined guide rail; the combined guide rail comprises a pair of first guide rails and a pair of second guide rails, the guide directions of the first guide rails and the second guide rails are perpendicular to each other; the floating platform is assembled on the first guide rails by two end frames, and end portion sliding blocks are assembled on the two ends of the first guide rails and on the second guide rails by the end portion sliding blocks; The movement of the end portion sliding blocks of the first guide rails on the guide path of the second guide rails and the movement of the floating platform on the guide path of the first guide rails are realized by a driving motor, and the position keeping is realized by the driving motor.

4. The self-centering adjustable machining clamp apparatus of claim 1, wherein, The angle adjustment of the rotating seat is manually or electrically adjusted by one of a screw mechanism, a worm and gear mechanism, a ball screw mechanism and a harmonic gear mechanism.

5. The self-centering adjustable machine chucking device of claim 1, wherein, The multi-jaw chuck mechanism is detachably assembled on the driving frame, and different sizes of multi-jaw chuck mechanisms can be replaced to replace different sizes of workpieces.

6. The self-centering adjustable machine chucking device of claim 5, wherein, The non-axis workpiece assembly seat can replace the multi-jaw chuck mechanism on the driving frame after the multi-jaw chuck mechanism is removed, so as to clamp and subsequently process the non-axis workpiece.

7. The self-centering adjustable machine chucking device of claim 1, wherein, The distance between the pressing block and the pressing pad is 1-5 times the outer diameter of the workpiece to be processed.

8. The self-centering adjustable machining clamp apparatus of claim 1, wherein, The second fixing part is a half-joint clamping structure matched with the outer diameter of the workpiece to be processed, and is a detachable structure connected with the clamping body through an adjustable rigid frame or rigid connecting rod.

9. The self-centering adjustable machining clamp apparatus of claim 1, wherein, The threaded top block is provided with a torque amplification device to assist the threaded top block in the rotating operation of the outer end of the movable jaw.

10. A workpiece clamping method characterized by, The self-centering adjustable machining clamping device is used to fix and clamp the pipe shaft workpiece on the machine tool, and the specific operation steps are as follows: S1, the assembly part is fixed and assembled on the machine tool, and the floating platform space is reserved; then the multi-jaw chuck mechanism and the threaded top block matched with the outer diameter of the workpiece are selected, and the assembly of the multi-jaw chuck mechanism is completed on the driving frame of the assembly base; S2, the rotation angle of the multi-jaw chuck mechanism is adjusted by the rotating seat, and then the positioning and calibration of the multi-jaw chuck mechanism are completed on the floating platform and the electric control lifting seat in sequence, and the zero position is set; S3, the workpiece is clamped on the multi-jaw chuck mechanism, and the self-centering calibration clamping of the workpiece is completed by the clamping operation of the multi-jaw chuck mechanism, then the outer end of the threaded top block is pressed on the outer end of the movable jaw of the multi-jaw chuck mechanism, and the two-stage annular clamping of the workpiece is realized by the pressing block on the inner side of the movable jaw and the pressing pad, so as to complete the clamping of the workpiece; S4, during the processing, the axis of the workpiece clamped on the multi-jaw chuck mechanism is taken as the X axis, the horizontal radial of the workpiece clamped on the multi-jaw chuck mechanism is taken as the Y axis, and the vertical direction is taken as the Z axis, then: The position of the workpiece in the X-Y plane is adjusted by the floating platform; The position of the workpiece on the Z axis is adjusted by the electric control lifting seat; The inclination of the workpiece in the Y-Z plane is adjusted by the rotating seat; The rotation and speed of the multi-jaw chuck mechanism are controlled by the driving frame, and the machining operation is performed in cooperation with the head of the machine tool.

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