CN202079312U

CN202079312U - Spiral drill with changed spiral angles

Info

Publication number: CN202079312U
Application number: CN2011201283118U
Authority: CN
Inventors: 张建华
Original assignee: JIANGSU FEIDA DRILLS CO Ltd
Current assignee: JIANGSU FEIDA DRILLS CO Ltd
Priority date: 2011-04-27
Filing date: 2011-04-27
Publication date: 2011-12-21
Anticipated expiration: 2021-04-27

Abstract

The utility model belongs to a metal cutting tool technology and relates to a spiral drill with changed spiral angles. The spiral drill comprises a handle part and a working segment, wherein the working segment is provided with double spiral grooves; each spiral groove is divided into a front segment near the bill tip and a rear segment near the handle part; the spiral angle of the front segment is 35-38 degrees; the spiral angle of the rear segment is 15-17 degrees; and smooth transition exists between the front segment and the rear segment. The spiral drill with changed spiral angles is excellent in integrating cutting and chip removal, long in service life, stable in drilling and high in drilling quality.

Description

Change the fluted drill of helical angle

Technical field

The utility model belongs to the metal cutting tool technology, relates to a kind of fluted drill that changes helical angle.

Background technology

The fluted drill of standard is made of shank and active section, its active section is provided with double-helical groove, the helical angle of its spiral grooves is a fixed value, if it is using the excessive then chip removal difficulty of helical angle, the machinability of the too small then cutting edge of helical angle is relatively poor, existing standard fluted drill helical angle about 30 °, is difficult to take into account chip removal and cutting usually, finally all can cause drilling life of bit to descend.

Summary of the invention

Technical problem to be solved in the utility model is, provides that a kind of cutting and chip removal to fluted drill takes into account better, the fluted drill of long service life, borehole stability, variation helical angle that drilling quality is high.

The fluted drill of variation helical angle of the present utility model includes shank and active section, active section has the double helix groove, described double helix groove is divided near the leading portion of apex point with near these two parts of shank back segment, the helical angle of its leading portion is 35 °～38 °, the back segment helical angle is 15 °～17 °, and front and back seamlessly transit for two sections.

Segment length accounts for 10%～20% of active section total length before described.

Described apex point makes the core of apex point part thick thick less than other part cores by the cross reconditioning, and making the chisel edge anterior angle simultaneously is+3 °～+ 8 °.

Described active section leading portion has the part of one section diameter less than nominal diameter near apex point, forms ladder-type structure in the end.

The utility model has the advantages that:

1, the drill bit active section adopts the large helix angle groove near cutting tip, makes drill bit main cutting edge anterior angle increase, and cutting edge is more sharp; Partly adopt the low pitch angle groove near shank, make the boring chip removal smooth more; Improved overall performance;

2, cutting tip is the stairstepping of size diameter, during on the one hand for product boring incision, has reduced cutting force, has improved processing stability, on the other hand also for the ladder pass need, provide may and conveniently;

3, apex point cross reconditioning, reduced apex point core thick (being chisel edge length), increased chisel edge anterior angle (-50 °～-60 ° become+3 °～+ 8 °), become the shovel cutting by squeezing cutting by the working angles that makes chisel edge by standard, can reduce heat in metal cutting, reduce the apex point wearing and tearing; Reduce the axial compressive force (≈ 50%) of boring, bore square (≈ 30%), make drilling brisk.Because chisel edge shortens, help boring centering simultaneously, can obviously reduce the hole wall surface roughness, improve shape, the positional precision in aperture and hole.

4, through actual tests, under conditions such as identical cutting data and rapidoprint, relative standard's fluted drill, the utility model can improve 2～5 times of drilling life of bit.

Description of drawings

Fig. 1 is an overall structure schematic diagram of the present utility model;

Fig. 2 is the enlarged diagram of apex point part of the present utility model, and its projecting direction is the length direction of apex point chisel edge.

The specific embodiment

The utility model is described in further detail below in conjunction with embodiment and contrast test.

Embodiment one

With the high-speed steel bar of same production batch W6Mo5Cr4V2, Ф 10.80, produce Ф 10 specification fluted drill A samples and B sample (both Technologies for Heating Processing are identical), the A sample is existing standard fluted drill, and the B sample is a fluted drill of the present utility model, and concrete parameter is as follows:

A sample: length overall L=133mm, active section length L 1=87mm, 30 ° of active section helical angles, diameter d=10mm, the thick 1.6mm of apex point core, chisel edge anterior angle γ=-52 °;

B sample: length overall L=133mm, active section length L 1=87mm, active section leading portion length L 2=15mm, 1=37 ° of leading portion helical angle ω, 2=16 ° of back segment helical angle ω, diameter d=10mm, near apex point step portion minor diameter d1=6.8mm, the thick 0.15mm of apex point core, chisel edge anterior angle γ=5 °.

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 350*40 modifier treatment, hardness HB208～212.The drilling blind hole is with the cooling of the oil emulsion aqueous solution.Its function life-span result of the test sees Table 1, table 2.

Table 1(B sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												363	391	489	471	369	380	512	575	269	498	4317	?

Table 2(A sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												144	130	125	168	143	138	99	145	102	135	1329	?

Embodiment two

With the high-speed steel bar of same production batch W9Mo3Cr4V, Ф 6.6, produce Ф 6.0 specification straight shank twist drill A samples and B sample (Technology for Heating Processing is identical), the A sample is existing standard fluted drill, and the B sample is a fluted drill of the present utility model, and concrete parameter is as follows:

A sample: length overall L=101mm, active section length L 1=63mm, 30 ° of active section helical angles, diameter d=6mm, the thick 1.05mm of apex point core, chisel edge anterior angle γ=-53 °;

B sample: length overall L=101mm, active section length L 1=63mm, active section leading portion length L 2=10mm, 1=36 ° of leading portion helical angle ω, 2=16 ° of back segment helical angle ω, diameter d=6mm, near apex point step portion minor diameter d1=4.2mm, the thick 0.12mm of apex point core, chisel edge anterior angle γ=4 °.

Test method: with TK7640 type digital control vertical boring and milling machine, cutting speed: 28m/min, amount of feeding 0.17mm/r, drilling degree of depth 20mm.Cutting examination base: 40Cr Ф 300*30 modifier treatment, hardness HB212～218.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(B sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												945	1102	1339	1543	1553	1745	1335	1162	1039	959	12722	?

Table 4(A sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												401	458	366	383	372	443	279	380	497	477	4056	?

Claims

1. fluted drill that changes helical angle, include shank and active section, active section has the double helix groove, it is characterized in that: described double helix groove is divided near the leading portion of apex point with near these two parts of shank back segment, the helical angle of its leading portion is 35 °～38 °, the back segment helical angle is 15 °～17 °, and front and back seamlessly transit for two sections.

2. the fluted drill of variation helical angle according to claim 1 is characterized in that: segment length accounts for 10%～20% of active section total length before described.

3. the fluted drill of variation helical angle according to claim 1 and 2 is characterized in that: apex point makes the core of apex point part thick thick less than other part cores by the cross reconditioning, and making the chisel edge anterior angle simultaneously is+3 °～+ 8 °.

4. the fluted drill of variation helical angle according to claim 1 and 2 is characterized in that: described active section leading portion has the part of one section diameter less than nominal diameter near apex point, forms ladder-type structure in the end.