A cutting tool for machining the bottom hole of the threaded hole in the crankshaft flywheel end flange.

Abstract

This utility model discloses a cutting tool for machining the bottom hole of the threaded hole in the flange of a crankshaft flywheel. It comprises a guide section, a cutting section, and a tool holder connected sequentially. A transition rounded chamfer is provided at the connection between the guide section and the cutting section. The diameter of the guide section is smaller than the diameter of the cutting section, and the guide angle of the guide section is 140°. The advantages of this utility model are: because the guide angle of the guide section is changed from 118° in the prior art to 140°, the initial positioning is not too fast, but rather a smooth cutting process, thus ensuring accurate positioning; simultaneously, the angle between the cutting surface formed by the guide section after cutting and the cutting edge of the cutting section becomes larger, thus narrowing the chips and reducing defects such as poor chip removal and chip scratches on the machined surface; furthermore, the transition rounded chamfer at the connection between the guide section and the cutting section reduces stress concentration points, thereby improving product quality.

Description

Technical Field

[0001] This utility model relates to the field of machinery, specifically a cutting tool, and more specifically a drilling tool. Background Technology

[0002] In the manufacturing and machining of crankshaft flywheel end flanges, the machining quality of the threaded hole's pilot hole is crucial. Current processes involve direct drilling, resulting in a sharp transition between the pilot hole's sidewall and the bottom surface, which easily leads to stress concentration. During machining, the inability to precisely control dimensional and positional accuracy often causes deviations in the pilot hole, affecting subsequent thread machining and overall assembly quality. Furthermore, poor chip removal during machining allows chips to easily scratch the machined surface, increasing surface roughness. In addition, rapid tool wear and frequent tool replacements not only reduce production efficiency but also increase machining costs. Therefore, there is an urgent need to design a new type of tool to solve these problems. Utility Model Content

[0003] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a tool for machining the bottom hole of the threaded hole on the crankshaft flywheel end flange. The tool is composed of a guide section, a cutting section, and a tool holder section connected in sequence. A transition arc chamfer is provided at the connection between the guide section and the cutting section. The diameter of the guide section is smaller than the diameter of the cutting section, and the guide angle of the guide section is 140°. The radius of the arc chamfer is 1.7mm.

[0004] The advantages of this invention are: because the guide angle of the guide part is changed from 118° in the prior art to 140°, the cutting is relatively smooth during the initial positioning, thus ensuring accurate positioning; at the same time, the angle between the cutting surface formed by the guide part after cutting and the cutting edge of the cutting part becomes larger, thus reducing chip resistance, improving chip removal, and improving the defect of chips scratching the machined surface; in addition, a transition arc chamfer is set at the connection between the guide part and the cutting part, reducing stress concentration points and achieving the goal of improving product quality. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of the structure of this utility model;

[0006] Figure 2 for Figure 1 Enlarged view of point A;

[0007] Figure 3 A schematic diagram comparing the cutting angles of different guide parts;

[0008] Figure 4 A schematic diagram showing the location of stress concentration points in existing technologies. Detailed Implementation

[0009] The present invention will now be described in detail with reference to the accompanying drawings. As shown in the drawings, the present invention is composed of a guide part 1, a cutting part 2 and a tool holder part 3 connected in sequence. A transition arc chamfer R is provided at the connection between the guide part 1 and the cutting part. The diameter d of the guide part 1 is smaller than the diameter D of the cutting part 2, and the guide angle α of the guide part is 140°.

[0010] The radius of the chamfer R is 1.7 mm.

[0011] like Figure 3 As described above, when the guide angle of the guide part is changed from 118° in the prior art to 140°, the angle between the cutting surface 4 formed after the guide part is cut and the cutting edge of the cutting part becomes larger, that is, angle c is greater than angle d. Therefore, during cutting, the axial length of the guide part will be reduced by the length m of the cutting force, that is, the chip is shorter and the chip removal is more optimized. In addition, a transition arc chamfer is set at the connection between the guide part and the cutting part, which reduces stress concentration points and achieves the purpose of improving product quality.

Claims

1. A cutting tool for machining the bottom hole of the threaded hole in the flange at the end of a crankshaft flywheel, comprising a guide part, a cutting part, and a tool holder part connected in sequence, characterized in that: The transition arc chamfer is arranged at the joint of the guiding part and the cutting part; the diameter of the guiding part is smaller than that of the cutting part, and the guiding angle of the guiding part is 140°.

2. The tool for machining the crankshaft flywheel end flange thread hole bottom hole according to claim 1, characterized in that: The radius of the arc chamfer is 1.7 mm.

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