A tooling device for machining notched test specimens

Abstract

This utility model provides a turning tool device for notched sample machining, including an indexable insert, a tool holder, and a screw. The indexable insert and the tool holder are fixedly connected by the screw. The tool holder is a CNC external turning tool straight head tool holder, with a diamond-shaped insert mounting groove at the head. A threaded hole that mates with the screw is located in the center of the insert mounting groove. The indexable insert has a central through hole coaxial with the threaded hole in the middle. The insert is replaced and fixed by screwing through the screw and screwing it into the tool holder.

Description

Technical Field

[0001] This invention relates to the field of precision machining technology for metal materials, specifically to a turning tool device for machining notched specimens, applied to the turning of Kt notches on rod-shaped notched specimens. Background Technology

[0002] In the preparation of notched specimens for metallic materials, the selection of an appropriate processing technique has a decisive impact on the test results of the specimen's mechanical properties. The quality of notch processing is directly related to the degree of stress concentration, which in turn affects the accuracy and reliability of key indicators such as fracture toughness and fatigue life. Therefore, a precise, stable, and controllable notch processing method is one of the core steps in the pretreatment of materials for testing.

[0003] Currently, grinding is the most common method for notching metal rod-shaped specimens in China, primarily using cylindrical or thread grinding machines. In practice, the grinding wheel is typically dressed to match the geometry of the notch, and the notch is machined using a plunge grinding method. For Kt-type notched specimens, a shaped grinding wheel with the same radius as the notch is generally used for precision grinding; silicon carbide grinding wheels are often used for titanium alloys, while other high-strength alloys are often used in conjunction with alumina grinding wheels.

[0004] Although grinding offers high dimensional accuracy and surface quality control to a certain extent, it still has significant limitations in terms of processing cycle, process flexibility, equipment dependence, and grinding heat control. On the one hand, the forming wheel processing cycle is long and the adjustment is complex, making it difficult to adapt to the customized needs of multiple models and small batches of notched specimens. On the other hand, the grinding process can easily induce microcracks or heat-affected zone defects on the material surface, thereby affecting the mechanical property test results of the specimens. In addition, existing grinding processes require a high level of expertise from both equipment and operators, and the consistency and controllability of the processing process still need to be improved.

[0005] In contrast, turning offers advantages such as a simpler process path, greater equipment versatility, and higher processing efficiency. If precise machining of notch geometry (such as fillet radius, notch depth, and opening angle) can be achieved through specialized turning tool design, ensuring the machined surface is free of scratches, cracks, and other macroscopic defects, it will help improve the quality and efficiency of notched specimen preparation. However, the current lack of specialized turning tooling devices for notched specimen preparation hinders the development and widespread adoption of this approach.

[0006] In summary, designing a turning tool device with a reasonable structure, high machining accuracy, and suitability for notched sample preparation has become an urgent technical problem to be solved. Summary of the Invention

[0007] To overcome a series of defects in the existing technology, the purpose of this utility model is to provide a turning tool device for notched sample machining, including an indexable insert 1, a tool holder 2, and a screw 3. The indexable insert 1 and the tool holder 2 are fixedly connected by the screw 3. The tool holder 2 is a CNC external turning tool straight head tool holder, with a diamond-shaped insert mounting groove 4 at the head. The insert mounting groove 4 has a threaded hole 5 in the center that mates with the screw 3. The indexable insert 1 has a central through hole coaxial with the threaded hole 5 in the middle. The screw 3 passes through the insert and is screwed into the tool holder 2 to achieve replaceable and fixed insert.

[0008] Furthermore, the indexable insert 1 has multiple cutting edges, the ends of which are rounded to R0.2mm.

[0009] Furthermore, the overall shape of the indexable blade 1 is rhomboid, with a small apex angle of 60.16°.

[0010] Furthermore, the indexable insert 1 is a PCD composite cutting insert, which is formed by welding a PCD layer 6 and a high-temperature alloy substrate layer together by directional explosion method. The thickness of the PCD layer 6 is 0.7 mm and the length is 4.27 mm.

[0011] Furthermore, the opening angle of the blade mounting groove 4 is 55.7°, the length of the short diagonal of the blade mounting groove 4 is 10.76 mm, and the half-length dimension of the long diagonal of the blade mounting groove 4 is 9.9 mm.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1) By rationally designing the blade geometry and mounting structure, and using indexable blades made of high-performance materials, rapid and stable processing of Kt notches on bar samples was achieved, significantly improving sample preparation efficiency and adapting to the continuous processing needs of various models and batches of samples.

[0014] 2) PCD composite material is used as the main cutting edge of the insert, which has extremely high hardness and excellent wear resistance. During the machining process, it can effectively extend the tool life, reduce the tool change frequency, and reduce the overall machining cost.

[0015] 3) The tool material has good thermal stability and thermal conductivity, which effectively controls the heat accumulation generated during the cutting process, reduces the changes in the microstructure of the material caused by high temperature, and ensures the integrity of the structure and surface quality of the notch machining area.

[0016] 4) The tool structure and blade fillet design can precisely control the size and shape of the Kt notch, meet the requirements of high-precision notch preparation, and ensure that the cutting surface is free of scratches, cracks and other defects, thus ensuring the accuracy and consistency of the subsequent mechanical property test results of the material.

[0017] 5) This device is suitable for the preparation of notches for various metal materials and rod-shaped specimens of different specifications. It can be widely used in the fields of mechanical property evaluation of metal materials, fatigue testing and fracture mechanics research, providing high-quality sample preparation for scientific research and industrial testing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the indexable blade in an embodiment of this utility model;

[0019] Figure 2 This is a schematic diagram of the tool holder structure in an embodiment of this utility model;

[0020] Figure 3 This is a schematic diagram of the installation of the indexable blade and the tool holder in an embodiment of this utility model.

[0021] In the diagram: 1, indexable insert; 2, tool holder; 3, screw; 4, insert mounting groove; 5, threaded hole; 6, PCD layer. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some embodiments of this utility model, not all embodiments.

[0023] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] The embodiments and directional terms described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] like Figure 1-3 As shown, a turning tool device for machining notched samples includes an indexable insert 1, a tool holder 2, and a screw 3. The indexable insert 1 and the tool holder 2 are fixedly connected by the screw 3. The tool holder 2 is a CNC external turning tool straight-head tool holder, and its head is provided with a diamond-shaped insert mounting groove 4 to realize the positioning and clamping of the insert. The insert mounting groove 4 is provided with a threaded hole 5 that mates with the screw 3 in the center to realize the fastening of the indexable insert 1. The insert is provided with a central through hole coaxial with the threaded hole 5 in the middle. The screw 3 passes through the insert and is screwed into the tool holder 2 to realize the replaceable and fixed insert.

[0026] Furthermore, the indexable insert 1 has multiple cutting edges with a radius of 0.2 mm at the tip.

[0027] Furthermore, the overall shape of the indexable blade 1 is rhomboid, with a small apex angle of 60.16°.

[0028] Furthermore, the indexable insert 1 is a PCD composite cutting insert, which is formed by welding a PCD layer 6 and a high-temperature alloy substrate layer together by directional explosion method. The thickness of the PCD layer 6 is 0.7 mm and the length is 4.27 mm.

[0029] The PCD layer is made of polycrystalline diamond, produced from graphite using a unique directional blasting method. Its structure is very similar to natural diamond, formed by unsaturated bonds. The PCD layer possesses excellent toughness, making it suitable for machining high-hardness materials. Furthermore, when used to machine non-ferrous metals, the PCD layer can create narrow machining grooves, resulting in a better machined surface. Polycrystalline diamond exhibits high hardness, high compressive strength, good thermal conductivity, and good wear resistance, enabling high machining accuracy and efficiency in high-speed cutting. Its rhomboid macroscopic design and excellent tip radius ensure consistent product dimensions throughout the lifespan of precision parts.

[0030] Furthermore, the opening angle of the blade mounting groove 4 is 55.7°, the length of the short diagonal of the blade mounting groove 4 is 10.76 mm, and the half-length dimension of the long diagonal of the blade mounting groove 4 is 9.9 mm.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A turning machining notched bar tool device comprising an indexable insert (1), a tool holder (2) and a screw (3), characterized in that, The indexable insert (1) and the tool holder (2) are fixedly connected by screws (3); the tool holder (2) is a CNC external turning tool straight head tool holder, with a diamond-shaped insert mounting groove (4) at the head, and a threaded hole (5) in the center of the insert mounting groove (4) that mates with the screw (3); the indexable insert (1) has a central through hole coaxial with the threaded hole (5) in the middle, and the insert is fixedly replaceable by screwing the screw (3) through the insert and screwing it into the tool holder (2).

2. A turning notched bar tool apparatus according to claim 1, wherein, The indexable insert (1) has multiple cutting edges, the ends of which are rounded to R0.2mm.

3. A turning notched bar tool apparatus as claimed in claim 2, wherein, The overall shape of the indexable blade (1) is rhomboid, and its small apex angle is 60.16°.

4. The device according to claim 1, wherein The indexable insert (1) is a PCD composite cutting insert, which is made by welding a PCD layer (6) and a high-temperature alloy substrate layer together by directional blasting. The thickness of the PCD layer (6) is 0.7 mm and the length is 4.27 mm.

5. A device for machining a notched bar specimen according to claim 1, characterized in that The opening angle of the blade mounting groove (4) is 55.7°, the length of the short diagonal of the blade mounting groove (4) is 10.76 mm, and the half length of the long diagonal of the blade mounting groove (4) is 9.9 mm.

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