CN2172690Y

CN2172690Y - Tap with large-diameter thread groove

Info

Publication number: CN2172690Y
Application number: CN 93204435
Authority: CN
Inventors: 李林
Original assignee: Tianjin Zhongde Modern Industrial Tech Training Centre
Current assignee: Tianjin Zhongde Modern Industrial Tech Training Centre
Priority date: 1993-02-27
Filing date: 1993-02-27
Publication date: 1994-07-27
Anticipated expiration: 2003-02-27

Abstract

The utility model discloses a screw tap with a large-diameter thread groove, relating to the screw taper of a coarse thread or fine thread hole with a major diameter. The taper body of the screw tap with a large-diameter thread groove is composed of a cutting taper part, a cutting guide part and a taper shank. The cutting taper part and the cutting guide part are respectively provided with taper screw threads and more than three left hand or right hand spiral cuttings chutes. The spiral angle of the spiral cuttings chute is between 20 DEG and 30 DEG, a working normal rake is between 9 DEG and 12 DEG, the length of the cutting taper part is between 20 mm and 28 mm, a cutting taper angle is between 12 DEG and 20' and 16 DEG and 50', and a grinding back angle is between 7 DEG and 8 DEG. The utility model has high durability, low manufacture cost and high tapping accuracy and efficiency, the direction of removing cuttings can be controlled, blind holes can be machined without the block of cuttings, and the labor intensity of operators can be relived.

Description

Tap with large-diameter thread groove

The utility model relates to the instrument of above major diameter coarse thread of a kind of M52 of being used for or the tapping of fine thread hole.

In the prior art, the major diameter coarse thread of metallic element or the processing in fine thread hole mainly contain two kinds of methods, promptly adopt the method for tapping behind first heavy boring screwed hole on the boring machine of the method for straight trough screw tap tapping, the method of tapping often will be subjected to the restriction of lathe and accessory behind elder generation's bore hole, when using radial tool post, the angle of cutter is relevant with the diameter of thread of being processed and pitch with dress nose angle degree, thereby must normal direction adorn cutter and revise cutting-tool angle, this complicated technical process is brought a lot of difficulty to the operator, and thread quality is difficult to guarantee, work efficiency is also very low, the screw tap that is used for the screwed hole tapping, its cone generally comprises the cutting tapering, cutting targeting part and taper shank, and cutting tapering and cutting targeting part have tapping thread tooth and chip area.Be used to process the screw tap of major diameter screwed hole, its chip area is axial straight trough, and the chip area number is more than or equal to 3.Adopt the straight trough screw tap boring the method for attacking the major diameter screwed hole in the celebrating, though its technology than first heavy boring after the method for tapping simple, but still defectives that exist some to give prominence to, at first, be prone to and disorderly detain and fall dental phenomenon, especially introduce or to withdraw from Shi Gengxian outstanding at screw tap, flat button phenomenon often appears in the screwed hole top, screwed hole difficult quality guarantee, percent defective are very high.Secondly, the efficient of straight trough screw tap tapping is very low, and screwed hole of every processing need repeatedly be changed screw tap (being I awl, II awl and III awl etc.); II is attacked, when III is attacked, is also needed operating personnel manually to introduce II awl, III awl, and labour intensity is big, and in addition, the chip removal direction the during tapping of straight trough screw tap is uncontrollable, easily causes stifled bits during processing blind hole.

The purpose of this utility model is improved the structure of major diameter screw tap, to guarantee the tapping quality, improves tapping efficient, alleviates labor intensity of operating staff, and control chip removal direction, prevents the generation of stifled bits phenomenon.

To achieve these goals, the utility model changes the chip area that screw tap cuts tapering and cutting targeting part into thread groove by the axle straight trough, and suitably designs relevant structural parameters.Following structure specific embodiment is described in further detail the technical characterictic of the utility model major diameter thread groove screw tap.

Accompanying drawing 1 is the structural representation of the utility model major diameter thread groove screw tap.

Accompanying drawing 2 is the profilograph of major diameter thread groove screw tap;

Accompanying drawing 3 is the A-A profile.

With reference to the accompanying

drawings

1,2,3, the utility model major diameter thread groove screw tap is made up of cutting tapering 1, cutting targeting part 2 and taper shank 3, cutting tapering and cut targeting part and have the above spirality chip area 5 of tapping thread tooth 4 and 3 roads; The spirality chip area can be left-handed or dextrorotation, and its helical angle is 20-30 °, normal rake γ ₀Be 9-12 °.Cutting cone minister degree L is 20-28mm, taper lead angle 2 ∮ be 12 ° 20 '-16 ° 50 ', relief grinding relief angle α ₀Be 7-8 °.

The utility model durability height, the processing and manufacturing cost is low, need not change screw tap when adopting the utility model processing major diameter screwed hole, and stable cutting, machining accuracy and working (machining) efficiency height, and can alleviate operator's labour intensity, stifled bits phenomenon can not appear during processing blind hole.Therefore, the utility model can be widely used in the major diameter coarse thread of metallic elements such as cast iron, carbon steel, steel alloy, non-ferrous metal and alloy or the tapping processing in fine thread hole.

Claims

1, a kind of screw tap that is used for above major diameter coarse thread of M52 or the tapping of fine thread hole, its cone is made up of cutting tapering, cutting targeting part and taper shank, cutting tapering and cutting targeting part have tapping thread tooth and chip area, chip area groove number is more than or equal to 3, left-handed or the right hand helix groove that is that is characterised in that described chip area of the present utility model, its helical angle is 20-30 °, normal rake γ _nBe 9-12 °; Described cutting cone minister degree L is 20-28mm, taper lead angle 2 ∮ be 12 ° 20 '-16 ° 50 ', relief grinding relief angle α _nBe 7-8 °.