CN101585093A

CN101585093A - Fluted drill with two kinds of core thickness increments

Info

Publication number: CN101585093A
Application number: CNA2009100311828A
Authority: CN
Inventors: 张建华; 谢荣杰
Original assignee: Jiangsu Feida Tools Co Ltd
Current assignee: Jiangsu Feida Drills Co., Ltd.
Priority date: 2009-04-29
Filing date: 2009-04-29
Publication date: 2009-11-25

Abstract

The invention belongs to the manufacturing technology of metal cutting tool, relate to a kind of twist drill with high strength and high cutting performance.Groove with fluted drill of two kinds of core thickness increments of the present invention is divided into two sections in the longitudinal direction, near apex point is leading portion, near shank is back segment, wherein the axial length of leading portion is 1～1.2 times of bit diameter size value, the core thickness increments value of leading portion groove is 1/10～1/8, the core thickness increments value 2.0/100～2.5/100 of back segment groove, it is 0.1d that apex point bores the core one-tenth-value thickness 1/10 ^0.830～0.12d ^0.830, wherein d is the fluted drill diameter.The present invention has improved the bulk strength and the cutting stability of fluted drill, and cutting resistance obviously reduces simultaneously, cuts brisk.Through the reality test, method of the present invention and product can significantly improve the serviceability and the life-span of fluted drill.

Description

Fluted drill with two kinds of core thickness increments

Technical field

The invention belongs to the manufacturing technology of metal cutting tool, relate to a kind of twist drill with high strength and high cutting performance.

Background technology

In the existing fluted drill structure, the core of fluted drill is thick to have a uniform core thickness increments usually on the whole axial length of groove, core thickness increments calculate to be obtained by Δ K/L usually, and wherein Δ K is the difference of the thick and front end core of ditch slot tail core between thick, and L is the axial length of groove.The fluted drill of this class formation is owing to be provided with uniform core thickness increments on the axial length direction of whole groove, fluted drill for same size, the cutting ability that less tip brill core thickness and bigger core thickness increments can improve drill bit is set, but the intensity of drill bit is lower; Less core thickness increments is set then needs to increase the brill core thickness of tip, though can improve drill bit intensity, its cutting ability is affected.

Summary of the invention

Technical problem to be solved by this invention is, a kind of have higher-strength, the fluted drill with two kinds of core thickness increments that the bit cutting performance is good are provided.

Groove with fluted drill of two kinds of core thickness increments of the present invention is divided into two sections in the longitudinal direction, near apex point is leading portion, near shank is back segment, wherein leading portion axial length be 1～1.2 times of bit diameter size value, the core thickness increments value of leading portion groove is 1/10～1/8, the core thickness increments value 2.0/100～2.5/100 of back segment groove, it is 0.1d that apex point bores the core one-tenth-value thickness 1/10 ^0.830～0.12d ^0.830, wherein d is the fluted drill diameter.

Fluted drill of the present invention is because its groove has bigger brill core thickness on most of length, the bulk strength and the cutting stability of fluted drill have been improved, simultaneously because one section groove of close apex point has bigger core thickness increments, thereby the outer core thickness of apex point is less, the fluted drill cutting resistance is obviously reduced, cut brisk.Through the reality test, method of the present invention and product can significantly improve the serviceability and the life-span of fluted drill.

Description of drawings

Fig. 1 is that fluted drill of the present invention bores core thickness distribution schematic diagram.

The specific embodiment

As figure, the groove of fluted drill of the present invention is divided into two sections in the longitudinal direction, near apex point is leading portion 1, near shank is back segment 2, wherein leading portion axial length L be 1～1.2 times of bit diameter size value, the core thickness increments value of leading portion groove is 1/10～1/8, the core thickness increments value 2.0/100～2.5/100 of back segment groove, and it is 0.1d that apex point bores the core one-tenth-value thickness 1/10 ^0.830～0.12d ^0.830, wherein d is the fluted drill diameter.

Embodiment one: with the high-speed steel bar of same production batch W6Mo5Cr4V2, Ф 6.6, produce Ф 6 specification straight shank twist drill A samples and B sample (Technology for Heating Processing is identical).

A sample test specimen: common ground straight-shank twist drill, apex point bore core thickness K:1.02, full ditch traverse drill core increment (Δ K/L) 1.62/100;

B sample test specimen: the ground straight-shank twist drill of two kinds of core thickness increments of the present invention, apex point bore core thickness K:0.49, in apex point 6.5mm scope, and core thickness increments 0.77/6.5; Thereafter the groove core thickness increments 2.32/100;

Test method: with TK7640 type digital control vertical boring and milling machine, cutting speed: 28m/min, amount of feeding 0.16mm/r, drilling degree of depth 18mm.Cutting examination base: 40Cr Ф 500*25 modifier treatment, hardness HB196～204.The drilling blind hole is with the cooling of the oil emulsion aqueous solution.Its result of the test sees Table 1, table 2.

Table 1 (A sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average	184	176	165	183	233	187	261	248	262	245	2144

Table 2 (B sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average	261	372	331	342	265	441	333	351	325	351	3372

Embodiment two: with the high-speed steel bar of same production batch W9Mo3Cr4V, Ф 10.8, produce Ф 10.0 specification straight shank twist drill A samples and B sample (Technology for Heating Processing is identical).

A sample test specimen: common ground straight-shank twist drill, apex point bore core thickness K:1.58, full groove core thickness increments 1.58/100;

B sample test specimen: two kinds of ground straight-shank twist drills that bore core thickness increment, apex point bore core thickness K:0.81, in apex point 11mm scope, and core thickness increments 1.22/11; Thereafter the groove core thickness increments 2.15/100;

Test method: with TK7640 type digital control vertical boring and milling machine, cutting speed: 28m/min, amount of feeding 0.25mm/r, drilling degree of depth 30mm.Cutting examination base: 40Cr Ф 500*35 modifier treatment, hardness HB192～204.The drilling blind hole is with the cooling of the oil emulsion aqueous solution.Its result of the test sees Table 3, table 4.

Table 3 (A sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average	145	162	159	187	163	175	195	167	171	179	1703

Table 4 (B sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average	221	257	316	187	256	241	276	289	261	297	2601

。

Claims

1, a kind of fluted drill with two kinds of core thickness increments, it is characterized in that: its groove is divided into two sections in the longitudinal direction, near apex point is leading portion, near shank is back segment, wherein leading portion axial length be 1～1.2 times of bit diameter size value, the core thickness increments value of leading portion groove is 1/10～1/8, the core thickness increments value 2.0/100～2.5/100 of back segment groove, and it is 0.1d that apex point bores the core one-tenth-value thickness 1/10 ^0.830～0.12d ^0.830, wherein d is the fluted drill diameter.