Turning tool for thin-wall disc parts with holes

Abstract

The utility model discloses a turning tool for a thin-wall disc part with a hole, which comprises a clamp main body and at least three expansion pins, the clamp main body is used for being connected with a three-jaw chuck on a lathe, the plurality of expansion pins are circumferentially arranged in a mounting hole of a part to be machined at intervals and are connected with the clamp main body through threaded locking pieces, and the expansion pins are connected with the clamp main body through the threaded locking pieces. The clamp body is provided with a plurality of stepped holes, the bottoms of the stepped holes are provided with locking threaded holes corresponding to the threaded locking pieces, and the upper portions of the stepped holes are provided with receding holes providing expansion spaces for the expansion pins. The clamp has the advantages of reducing clamping stress, preventing workpiece deformation and improving machining precision and stability.

Description

Technical Field

[0001] This utility model relates to a turning tooling, and more particularly to a turning tooling for thin-walled disc-shaped parts with holes. Background Technology

[0002] With the rapid development of mechanical manufacturing technology, thin-walled disc-shaped parts are widely used in aerospace, precision instruments, and other fields due to their lightweight and compact structure. However, these parts are prone to deformation during turning due to uneven clamping force or insufficient rigidity, leading to problems such as dimensional deviations and surface quality deterioration. This is especially true for thin-walled disc-shaped parts with holes, where the unique structure necessitates ensuring positioning accuracy while avoiding deformation caused by excessive clamping force. Achieving a high-precision, low-stress clamping process has become a key technical challenge restricting the machining efficiency and yield of thin-walled parts.

[0003] Currently, for turning thin-walled disc-shaped parts, general-purpose fixtures such as three-jaw chucks are commonly used for clamping. While these fixtures fix the workpiece using radial clamping force and offer advantages such as ease of operation and adaptability, they also have significant drawbacks in practical applications. For example, the centripetal clamping force of the three-jaw chuck acts directly on the thin-walled area of ​​the workpiece, leading to localized stress concentration and potentially causing elliptical deformation or radial warping. The superposition of clamping force and tool cutting force can exacerbate workpiece vibration, affecting machining stability. Furthermore, traditional fixture clamping mechanisms often require considerable space, are prone to interference with the tool path, and limit the flexible design of complex processes. For thin-walled disc-shaped parts with holes, existing fixtures often cannot fully utilize the hole structure for precise positioning, resulting in unsatisfactory clamping effects.

[0004] In summary, the shortcomings of existing technologies are mainly reflected in the following aspects: First, the clamping method mainly relies on radial force application, which makes it difficult to avoid workpiece deformation due to stress concentration, especially for thin-walled annular parts; second, conventional fixtures lack effective control over the axial displacement of the workpiece, making it prone to warping due to cutting forces during machining, further exacerbating deformation; third, the structural design of general-purpose fixtures often cannot simultaneously meet the requirements of low interference and high rigidity, resulting in limited room for process optimization; fourth, for thin-walled disc-shaped parts with holes, existing fixtures fail to fully utilize the hole structure for precise positioning and clamping, leading to poor clamping results. These problems severely restrict the improvement of machining accuracy for thin-walled parts, thus necessitating a new clamping scheme to overcome the bottlenecks of existing technologies. Utility Model Content

[0005] The purpose of this invention is to provide a turning fixture for thin-walled disc-shaped parts with holes, which can reduce clamping stress, prevent workpiece deformation, and improve machining accuracy and stability.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a turning fixture for thin-walled disc-shaped parts with holes, comprising a fixture body and at least three expansion pins. The fixture body is used to connect with a three-jaw chuck on a lathe. The multiple expansion pins are circumferentially spaced within the mounting holes of the workpiece to be machined and are connected to the fixture body via threaded locking elements to achieve radial expansion and axial locking. The fixture body is provided with multiple stepped holes, the bottom of which is provided with locking threaded holes corresponding to the threaded locking elements, and the upper part of which is provided with clearance holes to provide expansion space for the expansion pins.

[0007] Preferably, the expansion pin includes a lower main body section and an upper plurality of expansion plates. The main body section is through which the threaded locking member passes. The plurality of expansion plates are circumferentially spaced and fixed on the main body section. The expansion plates are evenly distributed along the axial direction, and there is a gap between adjacent expansion plates. When the threaded locking member is screwed in downward, the expansion plates expand outward and come into close contact with the mounting hole of the part to be processed, thereby achieving radial clamping.

[0008] Preferably, a stress relief hole is provided at the bottom of the gap.

[0009] Preferably, an annular groove is provided at the connection between the main body segment and the expansion piece, the cross-section of the annular groove is arc-shaped or V-shaped, and the stress relief holes are evenly distributed along the circumference of the annular groove.

[0010] Preferably, the clearance hole of the stepped hole is a conical structure, and the taper direction is consistent with the expansion direction of the expansion piece, which is used to guide the expansion piece to expand outward uniformly.

[0011] Preferably, the threaded locking element is a conical countersunk screw, and each of the expansion plates has an inclined surface at the upper part inside, and the multiple inclined surfaces cooperate with the conical surface of the conical countersunk screw.

[0012] Preferably, the end face of the threaded locking member is provided with an internal hexagonal groove or an internal cross groove.

[0013] Compared with existing technologies, the advantages of this utility model are as follows: This device achieves high-precision, low-stress clamping of thin-walled parts through the combined action of the fixture body and the expansion pins. Its working principle is as follows: The fixture body is connected to the lathe via a three-jaw chuck, ensuring the stability and rigidity of the tooling; multiple expansion pins are circumferentially spaced within the mounting holes of the workpiece and connected to the fixture body via threaded locking components. When the threaded locking components are screwed downwards, they engage with the locking threaded holes on the fixture body to achieve axial locking, simultaneously pushing the expansion plates of the expansion pins outwards to make close contact with the inner wall of the workpiece mounting hole, thus achieving radial clamping. Furthermore, as the threaded locking components continue to screw downwards, they apply a downward axial pulling force to the workpiece, preventing it from warping or deforming during processing; the stepped hole design on the fixture body provides expansion space for the expansion pins, with the locking threaded hole at the bottom of the stepped hole connecting to the threaded locking component, while the upper clearance hole provides sufficient space for the expansion plates to expand, ensuring a smooth and uniform expansion process.

[0014] The advantages of this structure are mainly reflected in the following aspects: First, through the dual action of radial expansion and axial tension, it not only achieves firm clamping of the workpiece, but also effectively prevents deformation of thin-walled parts caused by excessive clamping force; Second, the expansion plate of the expansion pin has a large contact area with the inner wall of the workpiece, which can evenly distribute the clamping force, reduce local stress concentration, and avoid damage to the workpiece surface; Third, the connection between the fixture body and the three-jaw chuck is simple and reliable, facilitating quick clamping and disassembly, and improving processing efficiency; Fourth, the design of the stepped hole and the clearance hole optimizes the expansion trajectory of the expansion pin, ensuring the uniformity and stability of the clamping force, and further improving the processing accuracy and workpiece surface quality. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 A three-dimensional structural diagram of a perforated thin-walled disk-like part;

[0017] Figure 2 This is a three-dimensional structural diagram of the present invention in its working state;

[0018] Figure 3 This utility model Figure 2 A schematic diagram of the three-dimensional structure in its decomposed state;

[0019] Figure 4 This is a cross-sectional view of the main body of the clamp in this utility model;

[0020] Figure 5 This is a three-dimensional structural diagram of the expansion pin in this utility model;

[0021] In the figure, 1. Fixture body; 2. Expansion pin; 3. Threaded locking element; 4. Stepped hole; 5. Locking threaded hole; 6. Clearing hole; 7. Main body section; 8. Expansion plate; 9. Clearance; 10. Stress relief hole; 11. Annular groove; 13. Inclined surface; 14. Internal hexagonal groove. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Example 1: As Figures 1-5 As shown, a turning fixture for thin-walled disc-shaped parts with holes includes a fixture body 1 and at least three expansion pins 2. The fixture body 1 is used to connect to a three-jaw chuck on a lathe. The multiple expansion pins 2 are circumferentially spaced in the mounting holes of the parts to be machined and are connected to the fixture body 1 through threaded locking members 3 to achieve radial expansion and axial locking. The fixture body 1 is provided with multiple stepped holes 4. The bottom of the stepped holes 4 is provided with locking threaded holes 5 corresponding to the threaded locking members 3. The upper part of the stepped holes 4 is provided with clearance holes 6 to provide expansion space for the expansion pins 2.

[0024] Example 2: Figures 1-5 As shown, unlike Embodiment 1, the expansion pin 2 includes a lower main body section 7 and an upper plurality of expansion pieces 8. The main body section 7 is through which the threaded locking member 3 passes. The plurality of expansion pieces 8 are fixed circumferentially at intervals on the main body section 7. The expansion pieces 8 are evenly distributed along the axial direction, and a gap 9 is left between adjacent expansion pieces 8. When the main body section 7 is screwed down, the expansion pieces 8 expand outward and come into close contact with the mounting hole of the part to be processed, thereby achieving radial clamping.

[0025] In the above structure, the expansion pin 2 consists of a lower main body section 7 and an upper plurality of expansion plates 8. The main body section 7 engages with the locking threaded hole 5 on the fixture body 1. When the threaded locking member 3 is screwed into the locking threaded hole 5, its end pushes the expansion plates 8 outward. The plurality of expansion plates 8 are circumferentially spaced and fixed on the main body section 7 and are evenly distributed along the axial direction. A gap 9 is left between adjacent expansion plates 8. This design allows the expansion plates 8 to expand flexibly in all directions when subjected to the action of the threaded locking member 3. When the expansion plates 8 expand outward, they come into close contact with the inner wall of the mounting hole of the workpiece to be processed, forming a uniform radial clamping force, thereby achieving a firm fixation of the workpiece. At the same time, when the threaded locking member 3 continues to screw downward, it will apply a downward axial pulling force to the workpiece, firmly connecting the fixture body and the workpiece, preventing the workpiece from warping or deforming due to the cutting force during processing.

[0026] The circumferential spacing and axial uniform distribution design of the expansion plates 8 enable the clamping force to be evenly transmitted to the inner wall of the workpiece, avoiding local stress concentration and effectively preventing deformation of thin-walled parts due to uneven clamping force. The gap 9 between the expansion plates 8 provides sufficient elastic space for the expansion process, allowing the expansion plates 8 to expand outward flexibly to adapt to mounting holes of different sizes, improving the versatility and adaptability of the tooling. The main body section 7 allows the threaded locking element 3 to pass through. The cooperation between the threaded locking element 3 and the locking threaded hole 5 not only achieves axial locking but also further enhances the clamping stability through downward pulling force, ensuring that the workpiece will not be displaced or vibrate during processing.

[0027] In this embodiment, a stress relief hole 10 is provided at the bottom of the gap 9.

[0028] In the above structure, a stress relief hole 10 is provided at the bottom of the gap 9 of the expansion piece 8, which helps to alleviate local stress concentration during the expansion process, so that the expansion piece 8 can deform more evenly when subjected to force, and will not break or deform the workpiece due to stress concentration. Especially for thin-walled parts, excessive clamping force or uneven stress can easily cause warping or distortion, while the stress relief hole 10 can reduce this risk and improve machining accuracy.

[0029] In this embodiment, an annular groove 11 is provided at the connection between the main body segment 7 and the expansion piece 8. The cross-section of the annular groove 11 is circular arc or V-shaped, and the stress relief holes 10 are evenly distributed around the annular groove 11.

[0030] The annular groove 11 provides a buffer when the expansion piece 8 expands under stress, allowing it to deform more evenly and preventing local overload or breakage due to uneven stress. The arc-shaped cross-section of the annular groove 11 smoothly disperses stress, reduces stress concentration, and improves the toughness of the expansion piece 8, while the V-shaped cross-section provides clear deformation guidance during expansion, making the expansion piece 8 more stable as it expands outward. Furthermore, the stress relief holes 10, evenly distributed circumferentially along the annular groove 11, further reduce local stress at the connection points, ensuring the expansion piece 8 maintains good elasticity and stability during radial expansion and axial locking, preventing fatigue damage caused by repeated stress.

[0031] Example 3: Figures 1-5 As shown, unlike Embodiment 2, the clearance hole 6 of the stepped hole 4 has a conical structure, and the direction of the taper is consistent with the expansion direction of the expansion piece 8, which is used to guide the expansion piece 8 to expand outward uniformly.

[0032] The purpose of the above design is to guide the expansion piece 8 to expand outwards uniformly, thereby optimizing the clamping effect. Its working principle is that when the threaded locking member 3 is screwed downwards into the locking threaded hole 5 of the fixture body 1, the expansion piece 8, while under axial force, is constrained and guided by the tapered clearance hole 6, allowing it to expand outwards gradually and uniformly along the tapered direction. This avoids deformation or damage due to uneven local force. Furthermore, the tapered clearance hole 6 provides a certain amount of space buffer, allowing the expansion piece 8 to unfold more smoothly and fit tightly against the inner wall of the workpiece mounting hole, thus forming a more stable radial clamping force. This structure not only improves the reliability and uniformity of clamping and reduces the risk of deformation caused by local stress concentration, but also adapts to mounting holes of different sizes, improving the versatility of the fixture.

[0033] In this embodiment, the threaded locking member 3 is a conical countersunk screw, and each expansion piece 8 has an inclined surface 13 on its upper part, and the multiple inclined surfaces 13 cooperate with the conical surface of the conical countersunk screw.

[0034] In this structure, the threaded locking element 3 uses a tapered countersunk screw, and each expansion piece 8 has an inclined surface 13 on its upper part. Multiple inclined surfaces 13 cooperate with the tapered surface of the tapered countersunk screw. The purpose of this design is to achieve uniform expansion and stable clamping of the expansion piece 8 through the force of the tapered surface. When the tapered countersunk screw is screwed in, its tapered surface applies a radial thrust downward along the inclined surface 13 inside the expansion piece 8, causing the expansion piece 8 to expand outward along the direction of the inclined surface 13 when under force, thereby tightly adhering to the inner wall of the workpiece mounting hole and achieving a stable radial clamping force. At the same time, the tapered surface design of the tapered countersunk screw can evenly distribute the clamping force, ensuring that the expansion piece 8 will not experience excessive local force during the expansion process, and avoiding deformation of the workpiece due to uneven clamping force.

[0035] In this embodiment, the end face of the threaded locking member 3 is provided with an internal hexagonal groove 14 or an internal cross groove.

[0036] By providing an internal hexagonal groove 14 or an internal cross groove on the end face of the threaded locking member 3, it can be adapted to corresponding standard tools (such as hex wrenches or Phillips screwdrivers), thereby achieving efficient and secure locking and unlocking. Compared with externally driven bolt designs, the internal hexagonal groove 14 or internal cross groove can reduce the exposed part, avoid interference caused by tool contact or high-speed rotation, and improve the safety of the fixture.

[0037] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A turning tooling fixture for thin-walled disc-like parts with holes, comprising a chuck body for connection with a three-jaw chuck on a lathe, and at least three expansion pins, characterised in that: A plurality of said expansion pins are circumferentially spaced in the mounting hole of the part to be machined, and are connected to the clamp body by a threaded locking member to achieve radial expansion and axial locking.

2. The turning tooling apparatus for thin-walled disc-shaped parts with holes according to claim 1, characterized in that: Said expansion pin includes a lower body segment and an upper plurality of expansion pieces, said body segment for said threaded locking member to pass through, a plurality of said expansion pieces are circumferentially fixed on said body segment, said expansion pieces are uniformly distributed along the axial direction, and a gap is left between adjacent said expansion pieces; when said threaded locking member is screwed down, said expansion pieces expand outward, tightly contact with the mounting hole of the part to be machined, and achieve radial clamping.

3. The turning tooling fixture for thin-walled disc-like parts with holes according to claim 2, characterized in that: The bottom of said gap is provided with a stress relief hole.

4. The turning tooling apparatus for thin-walled disc-shaped parts with holes according to claim 3, characterized in that: The connection between said body segment and said expansion pieces is provided with an annular groove, the cross section of said annular groove is arc-shaped or V-shaped, and said stress relief hole is uniformly distributed along said annular groove.

5. The turning tooling fixture for thin-walled disc-like parts with holes according to claim 3, characterized in that: The clearance hole of said stepped hole is a conical structure, the taper direction is consistent with the expansion direction of said expansion piece, and is used to guide the uniform expansion of said expansion piece outward.

6. The turning tooling fixture for thin-walled disc-shaped parts with holes according to claim 2, characterized in that: Said threaded locking member is a conical countersunk screw, the upper part of each said expansion piece is provided with an inclined surface, and a plurality of said inclined surfaces cooperate with the tapered surface of said conical countersunk screw.

7. The turning tooling fixture for thin-walled disc-shaped parts with holes according to claim 2, characterized in that: The end surface of said threaded locking member is provided with an internal hexagonal groove or an internal cross groove.

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