CN218694648U

CN218694648U - Double-taper-angle spiral-groove screw tap

Info

Publication number: CN218694648U
Application number: CN202223016195.8U
Authority: CN
Inventors: 邵金奎
Original assignee: Taizhou Shaoshi Tool Co ltd
Current assignee: Taizhou Shaoshi Tool Co ltd
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2023-03-24
Anticipated expiration: 2032-11-14

Abstract

The utility model provides a biconical angle helicla flute screw tap belongs to cutting tool technical field. The spiral groove tap solves the problems that when the existing spiral groove tap is used for flexible tapping, a plurality of threads at the tapping end are frequently over-cut, and the back thread tooth side of the spiral groove tap is in a sawtooth shape, so that the precision is influenced, and the surface quality of threads is also deteriorated. The double-taper-angle spiral groove tap comprises a cutting part, a calibration part, a spiral groove, a handle part and a square tail, wherein the cutting part is provided with a front conical surface and a rear conical surface, and the cutting cone angle Kr1 of the front conical surface is larger than the cutting cone angle Kr2 of the rear conical surface. The utility model discloses a with the design manufacturing of cutting part for the biconical angle structure have prevent that the overcut phenomenon from taking place and the higher advantage of cutting accuracy.

Description

Double-taper-angle spiral-groove screw tap

Technical Field

The utility model belongs to the technical field of cutting tool, a screw tap is related to, in particular to biconical angle helicla flute screw tap.

Background

The screw tap is a common tool for processing internal threads, and can be divided into a spiral groove screw tap, an edge inclination angle screw tap, a straight groove screw tap, a pipe screw tap and the like according to the shapes, the spiral groove screw tap in the prior art is shown in figure 1 and mainly comprises a cutting part 1, a calibration part 2, a spiral groove 3, a handle part 4 and a square tail 5, the cutting part 1 is conical, the thread processing is decomposed on each edge lobe together with the groove and the threads, the layer-by-layer cutting is carried out, the internal thread processing is completed, the cutting part is also called a cutting cone, a cone angle Kr, and the section of the cutting part is enlarged and is shown in figure 2.

The helicla flute screw tap slot is the heliciform, and the oblique angle cutting control smear metal is got rid of to stalk portion 4, along with attacking gradually of cutting awl, and the axial force of orientation attack the direction constantly increases, and when flexible tapping, the number tooth screw that often makes the end of attacking takes place "overcut" phenomenon, and its back of the body screw flank is the cockscomb structure, not only influences the precision, still worsens screw surface quality.

Disclosure of Invention

The utility model aims at the above-mentioned problem that exists among the prior art, provide one kind with the helicla flute screw tap of cutting part design manufacturing for the biconical angle structure.

The purpose of the utility model can be realized by the following technical proposal: a double-cone spiral flute tap comprises a cutting part, a calibration part, a spiral flute, a handle part and a square tail, wherein the cutting part is provided with a front conical surface and a rear conical surface, and the cutting cone angle Kr1 of the front conical surface is larger than the cutting cone angle Kr2 of the rear conical surface.

Compared with the prior art, the double-taper-angle spiral fluted tap designs the cutting part into a front conical surface and a rear conical surface, and the taper angle Kr1 of the front conical surface is larger than the taper angle Kr2 of the rear conical surface so as to increase the backward axial force formed by the factors of the cutting cone and reduce the forward axial resultant force; on the other hand, the back tooth profile of the screw tap is enlarged, the supporting area for guiding and feeding the tapping is increased, the cutting thickness of each tooth is increased, and the sawteeth of the processed thread back tooth profile are reduced, so that the purpose of solving the tapping defect of the spiral fluted screw tap in the prior art is achieved, the over-cutting phenomenon is prevented, and the cutting precision is higher.

Drawings

FIG. 1 is a schematic view of the overall structure of a prior art spiral fluted tap;

FIG. 2 is a cross-sectional view of a cutting portion of a prior art spiral fluted tap;

FIG. 3 is a schematic view of the overall structure of the present double-tapered spiral fluted tap;

FIG. 4 is a cross-sectional view of the cutting portion of the present double-tapered spiral fluted tap;

in the figure, 1, cutting part; 1a, a front conical surface; 1b, a rear conical surface; 2. a calibration section; 3. a spiral groove; 4. a handle; 5. and (4) square tail.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

As shown in fig. 3 and 4, the double-tapered spiral fluted tap includes a cutting portion 1, a calibration portion 2, a spiral flute 3, a shank portion 4 and a square tail 5, wherein the cutting portion 1 has a front tapered surface 1a and a rear tapered surface 1b, and a cutting taper angle Kr1 of the front tapered surface 1a is larger than a cutting taper angle Kr2 of the rear tapered surface 1 b.

The taper angle Kr1 of the front conical surface 1a is designed to be larger than the taper angle Kr2 of the rear conical surface 1b, so that the backward axial resultant force formed by the conical cutting cone factor is increased, the forward axial resultant force is reduced, meanwhile, the design enables the back tooth profile BC of the screw tap to be increased, the support area for guiding and feeding tapping is increased, the cutting thickness of each tooth is increased, and the sawteeth of the processed thread back tooth profile are reduced.

To be more specific, the cutting cone angle Kr1 of the front tapered surface 1a is 20 to 40 degrees, and the cutting cone angle Kr2 of the rear tapered surface 1b is 10 to 20 degrees.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Although various terms are used more herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any one of the additional limitations of the present invention.

Claims

1. A double-taper-angle spiral fluted tap comprises a cutting part (1), a calibration part (2), a spiral groove (3), a handle part (4) and a square tail (5), and is characterized in that the cutting part (1) is provided with a front conical surface (1 a) and a rear conical surface (1 b), and the cutting cone angle Kr1 of the front conical surface (1 a) is larger than the cutting cone angle Kr2 of the rear conical surface (1 b).