Compound tool for micro-hole reaming and extrusion finishing

Abstract

The application discloses a compound tool for micro-hole reaming and extruding finishing, which comprises a reaming blade, an extruding part and a handle; the extruding part is connected between the reaming blade and the handle; the diameter of the reaming blade is smaller than the diameter of a micro-hole to be processed, and the reaming blade is provided with a left helical structure; and the maximum diameter of the extruding part is equal to the diameter of the micro-hole to be processed. The application can improve the processing quality of the micro-hole wall and the consistency of the hole diameter.

Description

Technical Field

[0001] This application relates to the technical field of micro-hole machining equipment, and in particular to composite cutting tools for micro-hole reaming and finishing. Background Technology

[0002] There is a significant demand for micro-hole machining in industries such as meltblown nonwoven spinnerets, aerospace, and medical applications. Statistics show that micro-hole machining accounts for over 20% of the total machining time for micro-sized parts, with meltblown nonwoven spinneret micro-hole machining accounting for over 70%. Compared to other machining methods, micro-drilling offers significant advantages in terms of precision and cost, making it the primary method for machining 0.1-1mm micro-holes. However, micro-drilling struggles to achieve a hole wall roughness below 0.2μm, easily leading to issues such as microburrs, rough hole walls, and poor hole diameter consistency, severely impacting micro-hole machining quality and consequently affecting the performance of the parts. Summary of the Invention

[0003] To improve the machining quality and diameter consistency of micro-hole walls, this application provides a composite tool for micro-hole reaming and finishing. The technical solution is as follows:

[0004] A composite tool for micro-hole reaming and finishing includes a reaming edge, a finishing section, and a shank; the finishing section is connected between the reaming edge and the shank; the diameter of the reaming edge is smaller than the diameter of the micro-hole to be processed, and the reaming edge is provided with a left-hand helical structure; the maximum diameter of the finishing section is equal to the diameter of the micro-hole to be processed.

[0005] Optionally, the diameter of the reaming edge is 5-10 μm smaller than the diameter of the micropore to be processed.

[0006] Optionally, the left helix angle of the reaming edge ranges from 5 to 15°.

[0007] Optionally, the diameter of the calendering section is the largest in the middle and gradually decreases at both ends, and the calendering section transitions in a teardrop-shaped arc from the middle to both ends.

[0008] Optionally, the diameter of the transition section from the reaming edge to the calendering section gradually increases with the teardrop-shaped arc curve.

[0009] In summary, this application has the following beneficial effects:

[0010] 1. After machining through holes with micro-diameter drill bits, composite tools are used. By setting up the reaming section and the reaming edge, the two processes of micro-reaming and shaping can be completed in one finishing process, reducing the time for secondary clamping or tool changing and improving machining efficiency.

[0011] 2. The diameter of the reaming blade is slightly smaller than the diameter of the machined hole, and it is set to a left-hand spiral structure; this allows the chips to be naturally discharged downwards from the micro-hole by gravity, without scratching the already machined hole wall, thus improving the surface finish of the hole wall; when used with the extrusion section, it can perform fine reaming and shaping of the micro-hole, improving the accuracy and consistency of the hole diameter. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this embodiment;

[0013] Figure 2 This is a schematic diagram of the reaming edge in this embodiment;

[0014] Figure 3 This is a schematic diagram of the extrusion section in this embodiment.

[0015] Explanation of reference numerals in the attached drawings: 1. Reaming edge; 2. Extrusion section; 3. Shank. Detailed Implementation

[0016] The present application will be further described in detail below with reference to the accompanying drawings.

[0017] This application discloses a composite tool for micro-hole reaming and finishing, comprising a reaming edge 1, a finishing section 2, and a shank 3. The finishing section 2 is integrally connected between the reaming edge 1 and the shank 3. Using this composite tool, two processes—micro-hole reaming and shaping—can be completed in a single finishing operation, reducing the time required for secondary clamping or tool changes and improving processing efficiency.

[0018] Specifically, the diameter of the reaming edge 1 is 5-10 μm smaller than the diameter of the micro-hole to be machined. The reaming edge 1 is equipped with a left-hand helical structure with a left-hand helical angle ranging from 5-15°, which allows the chips to be naturally discharged downwards from the micro-hole by gravity without scratching the machined hole wall. The reaming process can remove the micro-burrs left by drilling and improve the surface finish of the hole wall.

[0019] The calendering section 2 has the largest diameter in the middle, gradually decreasing in size at both ends, and transitions in a teardrop-shaped arc from the middle to both ends. The maximum diameter of the middle section of the calendering section 2 is equal to the diameter of the micropore to be processed. The surface curvature of the calendering section 2 is relatively smooth, which can prevent stress concentration during the shaping process and thus avoid scratching the hole wall.

[0020] The diameter of the transition section from the reaming edge 1 to the extrusion section 2 gradually increases with a teardrop-shaped arc curve. The end of the extrusion section 2 furthest from the reaming edge 1 also has a transition section. During the finishing process, the extrusion force on the hole wall increases uniformly, resulting in a uniform and effective reaming and shaping effect, while preventing stress concentration and avoiding scratches on the hole wall, thus improving the accuracy and consistency of the hole diameter.

[0021] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A composite tool for micro-hole reaming and finishing, characterized in that: It includes a reaming edge, a polishing section, and a shank. The polishing section is integrally connected between the reaming edge and the shank to form a composite tool, used to complete two processes, micro-hole enlargement and shaping, in a single finishing process. The diameter of the reaming edge is smaller than the diameter of the micro-hole to be processed, and the reaming edge is provided with a left-hand helical structure. The maximum diameter of the polishing section is equal to the diameter of the micro-hole to be processed. The left-hand helical angle of the reaming edge is in the range of 5-15°. The polishing section has the largest diameter in the middle, which gradually decreases at both ends, and the polishing section transitions in a teardrop-shaped arc from the middle to both ends. The diameter of the transition part from the reaming edge to the polishing section increases gently with the teardrop-shaped arc curve.

2. The composite tool for micro-hole reaming and finishing according to claim 1, characterized in that: The diameter of the reaming blade is 5-10 μm smaller than the diameter of the micro-hole to be processed.

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