CN102145401A

CN102145401A - Multi-blade tip twist drill with high cutting performance

Info

Publication number: CN102145401A
Application number: CN 201110106816
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: 2011-08-10

Abstract

The invention belongs to a metal cutting tool technology and relates to a multi-blade tip twist drill with high cutting performance. Two main cutting blades extend from two ends of a drill tip chisel edge to two sides of a drill bit, a rear tool face of the main cutting blade is provided with a groove by grinding, the main cutting blade close to the drill tip forms a J-shaped cutting blade, and a middle blade tip arranged in the middle of the main cutting blade is formed at the intersection point of the J-shaped cutting blade and the curve of the main cutting blade close to the edge of the drill bit. The invention has the advantages that the cutting performance of the twist drill can be improved, and the service life is prolonged.

Description

High cutting ability multiple-cutting-edge point fluted drill

Technical field

The invention belongs to the metal cutting tool technology, relate to a kind of high cutting ability multiple-cutting-edge point fluted drill.

Background technology

In the cutting end structure of common fluted drill, comprise two main cutting edges that extend to both sides of the edge from apex point, the shape of opening of every main cutting edge is generally one section full curve, that is to say, main cutting edge only intersects the formation apex point in drill margin and land except the apex point part, the drilling cuttings that forms when the fluted drill of this structure cuts is bigger, be unfavorable for chip removal and heat radiation, give service life of drill bit and bring adverse effect; In addition, the fluted drill apex point chisel edge anterior angle of standard is generally at-50 °～-60 °, and the angle, rear flank of the outer rib (land) of drill bit is generally 0 °, and the lifting that these all are unfavorable for cutting ability influences service life.But how these parameters are adjusted, and made it mutual coordination, can effectively improve the cutting ability and the service life of whole drill bit, still do not have desirable solution.

Summary of the invention

Technical problem to be solved by this invention provides the high cutting ability multiple-cutting-edge point fluted drill of a kind of cutting ability height, long service life.

In the high cutting ability multiple-cutting-edge point fluted drill structure of the present invention, two main cutting edges are extended to the drill bit both sides in its apex point chisel edge two ends, reconditioning goes out groove on the back knife face of main cutting edge, make the cutting edge that forms J-shaped near one section main cutting edge of apex point, the cutting edge of J-shaped forms the middle part blade tip that is positioned at the main cutting edge middle part with the intersections of complex curve of the main cutting edge of close drill margin.

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 °.

The angle, one section land rear flank of the close apex point of above-mentioned fluted drill is 5 °～12 ° by 0 ° of reconditioning of standard.

Advantage of the present invention is:

1, main cutting edge reconditioning J type groove forms second drift angle (blade tip), can make drilling cuttings thinner, and chip removal, cooling are more smooth, help boring centering.

2, apex point cross reconditioning reduced apex point core thick (being chisel edge length), increased chisel edge anterior angle (by standard-50 °～-60 ° become+3 °～+ 8 °), squeezes cutting by former chisel edge and becomes the shovel cutting, can reduce heat in metal cutting, reduces the apex point wearing and tearing; Reduce axial compressive force (≈ 50%), the brill square (≈ 30%) of boring, 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.

3, the wearing and tearing of twist drill grinder place can be reduced in angle, outer rib (land) reconditioning rear flank, improve drilling life of bit.

4, through verification experimental verification, the adjustment that each parameter relative standard fluted drill is done has produced and has helped the bit cutting performance and improve resultant effect service life.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the embodiment of the invention;

Fig. 2 is the front structure for amplifying schematic diagram of the cutting end of fluted drill embodiment of the present invention;

Fig. 3 is the end face structure for amplifying schematic diagram of the cutting end of fluted drill embodiment of the present invention.

The specific embodiment

As shown in the figure, in this high cutting ability multiple-cutting-edge point fluted drill structure, two main cutting edges are extended to the drill bit both sides in its apex point chisel edge two ends, reconditioning goes out groove on the back knife face of main cutting edge, make the cutting edge 1 that forms J-shaped near one section main cutting edge of apex point, the cutting edge of J-shaped forms the middle part blade tip 2 that is positioned at the main cutting edge middle part with the intersections of complex curve of the main cutting edge of close drill margin.Apex point makes the core of apex point part thick thick less than other part cores by the cross reconditioning, make simultaneously chisel edge anterior angle γ be one on the occasion of angle.Fluted drill forms one greater than 0 ° angle, rear flank α near one section land reconditioning of apex point.

The invention will be further described 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 a fluted drill of the present invention, and the B sample is existing standard fluted drill, and concrete parameter is as follows:

A sample: length overall L=133mm, active section length L 1=87mm, land reconditioning segment length L2=15mm, the thick 0.13mm of apex point core, chisel edge anterior angle γ=6 °, reconditioning part land rear flank angle α=12 °;

B sample: length overall L=133mm, active section length L 1=87mm, the thick 1.6mm of apex point core, chisel edge anterior angle γ=-52 °, land rear flank angle α=12 °.

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(A sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												305	359	316	382	341	216	265	331	387	196	3098	?

Table 2(B sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												156	135	126	86	139	166	123	168	106	152	1357	?

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 a fluted drill of the present invention, and the B sample is existing standard fluted drill, and concrete parameter is as follows:

A sample: length overall L=101mm, active section length L 1=63mm, land reconditioning segment length L2=9mm, the thick 0.1mm of apex point core, chisel edge anterior angle γ=5 °, reconditioning part land rear flank angle α=12 °;

B sample: length overall L=101mm, active section length L 1=63mm, the thick 1.05mm of apex point core, chisel edge anterior angle γ=-53 °, land rear flank angle α=12 °.

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(A sample test specimen boring result)

1#	2#	3#	4#	5#	6#	7#	8#	9#	10#	Add up to	Average
												945	896	939	1143	1099	1142	635	792	566	776	8933	?

Table 4(B sample test specimen boring result)

1#

2#

3#

4#

5#

6#

7#

8#

9#

10#

Add up to

Average

435

395

562

363

601

321

423

613

429

545

4687

?

Claims

1. one kind high cutting ability multiple-cutting-edge point fluted drill, two main cutting edges are extended to the drill bit both sides in its apex point chisel edge two ends, it is characterized in that: reconditioning goes out groove on the back knife face of main cutting edge, make the cutting edge 1 that forms J-shaped near one section main cutting edge of apex point, the cutting edge of J-shaped forms the middle part blade tip 2 that is positioned at the main cutting edge middle part with the intersections of complex curve of the main cutting edge part of close drill margin.

2. high cutting ability multiple-cutting-edge point fluted drill according to claim 1 is characterized in that: 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 °.

3. high cutting ability multiple-cutting-edge point fluted drill according to claim 1 and 2, it is characterized in that: fluted drill is 5 °～12 ° near the angle, rear flank of one section land of apex point.