A single-crystal disk cutter for machining the surface of medical Teflon plastic punches

Abstract

This application provides a single-crystal disc cutter for machining the surface of a medical Teflon plastic punch, including a tool holder, a collet, and a chip cutting section. The tool holder is located at one end of the collet, and a mounting groove is provided on the side of the collet. The chip cutting section is mounted in the mounting groove by bolts, and the lower end of the chip cutting section extends out of the mounting groove. A single-crystal diamond insert is embedded in the side of the lower end of the chip cutting section. The rake angle of the single-crystal diamond insert is 4° to 5°, and the clearance angle of the single-crystal diamond insert is 8° to 10°. This application uses a single-crystal diamond insert to cut into the Teflon material with a rake angle of 4° to 5°, generating a high-pressure stress field in the cutting zone, forcing the polymer chains to undergo directional slippage rather than elastic tearing. The 8° to 10° clearance angle design creates a micron-level gap space, suppressing material rebound and adhesion, and achieving continuous ribbon-like chips, which can obtain a Ra 0.2-0.4μm mirror surface. In addition, the ultra-high thermal conductivity of diamond in this application constructs a radial heat conduction path, allowing cutting heat to diffuse rapidly along the tool body.

Description

Technical Field

[0001] This application relates to the field of cutting tools for machining medical Teflon plastic punches, and in particular to a single-crystal cutting tool for machining the plane of medical Teflon plastic punches. Background Technology

[0002] In the field of precision medical device manufacturing, Teflon (PTFE) plastic punches are widely used in the molding of high-precision parts due to their excellent chemical inertness, low coefficient of friction, and biocompatibility. The machining of large flat surfaces of these punches requires a surface finish of Ra below 0.4 μm, and strict control of dimensional tolerances is necessary.

[0003] Traditional processing techniques typically employ a two-step method:

[0004] Preliminary machining stage: Use carbide end mills to rough mill the contour and plane of the punch;

[0005] Finishing stage: Relying on manual polishing or mechanical polishing equipment to improve surface smoothness.

[0006] However, this process has significant drawbacks:

[0007] After polishing, the surface finish can usually only reach Ra 0.8μm, which is difficult to meet the high standard requirement of Ra 0.4μm; Teflon material has extremely low thermal conductivity (about 0.25 W / m·K), and frictional heat accumulation during polishing leads to local temperature rise, causing thermal expansion and deformation of the material, resulting in dimensional deviations.

[0008] The material is soft, and the amount of material removed during polishing is difficult to control precisely, which can easily lead to over-polishing or under-polishing defects.

[0009] The secondary polishing process significantly extends the production cycle and increases labor costs.

[0010] To address these issues, the industry has attempted to optimize tool geometry or use multi-flute diamond end mills. However, the polymer chain structure of Teflon is prone to elastic recovery during cutting, and conventional tools still cause microscopic tearing and burrs, making it impossible to achieve an optical-grade surface. Especially in the machining of large flat surfaces, continuous tool feed is more likely to cause surface quality deterioration due to heat accumulation. Utility Model Content

[0011] The purpose of this application is to provide a special tool that can complete the high-precision planar machining of Teflon punches in one operation, fundamentally solving the contradiction between thermal deformation and surface finish.

[0012] A single-crystal disc cutter for machining the surface of a medical Teflon plastic punch includes a shank, a collet, and a cutting section. The shank is located at one end of the collet, and a mounting groove is provided on the side of the collet. The cutting section is mounted in the mounting groove by bolts, and the lower end of the cutting section extends out of the mounting groove. A single-crystal diamond cutting edge is embedded on the side of the lower end of the cutting section. The rake angle of the cutting edge of the single-crystal diamond cutting edge is 4° to 5°, and the clearance angle of the cutting edge of the single-crystal diamond cutting edge is 8° to 10°.

[0013] Furthermore, the rake angle of the cutting edge of the single-crystal diamond blade is 4°.

[0014] Furthermore, the rake angle of the cutting edge of the single-crystal diamond blade is 5°.

[0015] Furthermore, the rake angle of the cutting edge of the single-crystal diamond blade is 4.5°.

[0016] Furthermore, the back angle of the cutting edge of the single-crystal diamond blade is 8°.

[0017] Furthermore, the back angle of the cutting edge of the single-crystal diamond blade is 9°.

[0018] Furthermore, the back angle of the cutting edge of the single-crystal diamond blade is 10°.

[0019] Furthermore, at least one threaded hole is provided on the end face of the chuck.

[0020] Furthermore, the surface of the cutting portion is provided with at least one through hole.

[0021] The beneficial effects of this application are as follows:

[0022] This application uses a single-crystal diamond insert to cut into Teflon material with a rake angle of 4° to 5°, generating a high-pressure stress field in the cutting zone, which forces the polymer chains to undergo directional slip rather than elastic tearing; the design of an 8° to 10° clearance angle creates a micron-level gap space, suppressing material rebound and adhesion, and achieving continuous ribbon-like chips, which can obtain a mirror surface with Ra 0.2-0.4μm; in addition, the ultra-high thermal conductivity of diamond in this application constructs a radial heat conduction path, allowing cutting heat to diffuse rapidly along the tool body. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a single-crystal disk cutter for machining the plane of a medical Teflon plastic punch according to an embodiment of this application;

[0024] Figure 2 A schematic diagram of the single-crystal disk cutter for machining the plane of a medical Teflon plastic punch provided in one embodiment of this application;

[0025] Figure 3This is a schematic diagram of the structure of the chuck and the cutting part provided in an embodiment of this application;

[0026] Figure 4 A schematic diagram of the structure of the cutting section and the single-crystal diamond cutting tool provided in an embodiment of this application;

[0027] Figure 5 for Figure 4 A magnified view of a portion at point A;

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Tool holder; 200. Chuck; 300. Chip cutter; 400. Bolt; 500. Single-crystal diamond insert;

[0030] 210. Mounting slot; 220. Threaded hole;

[0031] 510. Front corner; 520. Back corner;

[0032] 310. Through hole; Detailed Implementation

[0033] 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 of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0034] In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," etc., are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In particular, the understanding of the term "upper" following a noun in the claims should be understood as meaning that the entire inner and outer surfaces of the structure referred to by the noun conform to the definition of "upper."

[0035] The following detailed description, in conjunction with the accompanying drawings and preferred embodiments, describes the specific implementation methods, structures, features, and effects provided in this application.

[0036] like Figures 1 to 5 As shown, a single-crystal disc cutter for machining the plane of a medical Teflon plastic punch includes a shank, a collet, and a cutting section. The shank is located at one end of the collet, and a mounting groove is provided on the side of the collet. The cutting section is mounted in the mounting groove by bolts, and the lower end of the cutting section extends out of the mounting groove. A single-crystal diamond insert is embedded on the side of the lower end of the cutting section. The rake angle of the cutting edge of the single-crystal diamond insert is 4° to 5°, and the clearance angle of the cutting edge of the single-crystal diamond insert is 8° to 10°.

[0037] The working principle of a single-crystal disk cutter for machining the surface of a Teflon plastic punch is as follows:

[0038] First, the tool holder is securely clamped in the spindle collet of a CNC machining center or other precision machine tool; the machine tool spindle rotates at high speed, driving the entire tool (tool holder, collet, cutting section and diamond insert) to rotate together.

[0039] The cutting section is bolted into a mounting groove on the side of the chuck, and its upper end (the part inlaid with diamond cutting blades) extends upward out of the mounting groove.

[0040] A high-speed rotating single-crystal diamond cutting tool contacts the surface of a Teflon workpiece; its sharp and ultra-hard cutting edge (4°-5° rake angle to ensure a balance between sharpness and strength, and 8°-10° clearance angle to reduce friction and material adhesion) acts like a precision "scraper." The cutting edge cuts into and scrapes the Teflon material laterally along the tangential direction of the tool's rotation using a peripheral milling method, forming chips.

[0041] Diamond inserts utilize their extremely high hardness and wear resistance to efficiently and precisely remove minute Teflon materials. Due to the softness and stickiness of Teflon, the extremely low coefficient of friction and chemical inertness of diamond effectively prevent material adhesion and buildup on the cutting edge (sticking). The precisely controlled rake and clearance angles optimize the cutting process: Rake angle (4°-5°): provides sufficient sharpness to reduce cutting forces, prevent tearing of soft materials, and maintain edge strength; Clearance angle (8°-10°): ensures sufficient clearance between the insert's flank face and the machined surface, minimizing friction and compression, and avoiding surface burns, burrs, or dimensional inaccuracies caused by material springback or stickiness.

[0042] The machine tool table drives the workpiece (or the tool drives itself) to perform precise feed motion relative to the rotating tool in the X / Y plane; the rapidly rotating diamond peripheral cutting edge moves on the workpiece surface according to the programmed path, and removes material layer by layer with high precision through continuous micro-cutting, finally forming the required smooth and flat punch surface.

[0043] like Figure 5 As shown, in one embodiment, the rake angle of the single-crystal diamond insert is 4°. This provides maximum edge strength and impact resistance, making it particularly suitable for machining Teflon materials containing hard fillers or requiring high impact resistance, while reducing the risk of chipping.

[0044] like Figure 5 As shown, in one embodiment, the rake angle of the cutting edge of the single-crystal diamond insert is 5°. This provides the sharpest cutting edge, significantly reduces cutting forces, makes cutting easier and chip removal smoother, and is particularly suitable for finishing and applications requiring low cutting forces, helping to reduce workpiece deformation.

[0045] like Figure 5 As shown, in one embodiment, the rake angle of the cutting edge of the single-crystal diamond insert is 4.5°. Achieving an optimal balance between edge strength and sharpness is a versatile choice that balances durability and cutting efficiency, suitable for most conventional Teflon surface machining.

[0046] like Figure 5 As shown, in one embodiment, the rake angle of the single-crystal diamond insert is 8°. This provides maximum edge support and structural strength, effectively resisting flank wear, and is particularly suitable for heavy cutting or applications requiring extremely high edge stability, thus enhancing tool durability.

[0047] like Figure 5 As shown, in one embodiment, the rake angle of the single-crystal diamond insert is 9°. This effectively reduces friction between the flank face and the workpiece while ensuring sufficient cutting edge support, balancing tool life and cutting efficiency / surface quality requirements. It is a versatile compromise solution.

[0048] like Figure 5 As shown, in one embodiment, the rake angle of the single-crystal diamond insert is 10°. This minimizes the friction and contact area between the flank face and the machined surface, significantly reducing cutting heat and material adhesion (important for Teflon), making it particularly suitable for finishing processes requiring high precision and high surface finish, resulting in better surface quality.

[0049] like Figure 2 As shown, in one embodiment, the end face of the chuck has at least one threaded hole. This can be used to install auxiliary tooling, such as a pipe connector bracket for air blowing or dust extraction, to promptly clean Teflon cutting debris during machining, ensuring a clean machining environment and improving the surface finish; or to install tool setting or inspection accessories to assist in precise control of the machining process.

[0050] like Figure 4 As shown, in one embodiment, the surface of the chip section has at least one through hole; in this embodiment, the surface of the chip section has at least three through holes. This facilitates adjustment of the chip section's mounting position.

[0051] The embodiments described above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A single crystal disk cutter for flat machining of medical Teflon plastic male molds, characterized in that: The tool includes a shank, a collet, and a cutting section. The shank is located at one end of the collet, and the side of the collet has a mounting groove. The cutting section is mounted in the mounting groove by bolts, and the lower end of the cutting section extends out of the mounting groove. A single-crystal diamond cutting blade is inlaid on the side of the lower end of the cutting section. The rake angle of the cutting edge of the single-crystal diamond cutting blade is 4° to 5°, and the clearance angle of the cutting edge of the single-crystal diamond cutting blade is 8° to 10°.

2. A single crystal disk cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The rake angle of the cutting edge of the single-crystal diamond cutting tool is 4°.

3. A single crystal disc cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The rake angle of the cutting edge of the single-crystal diamond cutting tool is 5°.

4. A single crystal disc cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The rake angle of the cutting edge of the single-crystal diamond cutting tool is 4.5°.

5. A single crystal disc cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The back angle of the cutting edge of the single-crystal diamond cutting tool is 8°.

6. A single crystal disk cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The back angle of the cutting edge of the single-crystal diamond cutting tool is 9°.

7. A single crystal disc cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The back angle of the cutting edge of the single-crystal diamond cutting tool is 10°.

8. A single crystal disk cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: At least one threaded hole is provided on the end face of the chuck.

9. A single crystal disc cutter for flat machining of a medical PTFE plastic punch according to claim 1, characterized in that: The surface of the cutting section has at least one through hole.

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