CN2719460Y

CN2719460Y - Miniature three-edge drilling bit

Info

Publication number: CN2719460Y
Application number: CN 200420077295
Authority: CN
Inventors: 颜灿然
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-20
Filing date: 2004-08-20
Publication date: 2005-08-24
Anticipated expiration: 2014-08-20

Abstract

The utility model provides a miniature three-edge drilling bit mainly used for the drilling operation of the printed circuit board, comprising a drilling body portion and a drilling handle portion. The drilling body portion is used for drilling holes on the printed circuit board and the drilling handle portion is used for fixing a hole drilling machine. The tip end of the drilling body portion is milled into three cutting edges with the same angle and a ridge is formed on each two cutting edges and the intersecting portion of the three ridges forms a conical point. The two sides of each ridge respectively form a cutting edge portion and a groove portion. Two opposite cutting edge portions and groove portions form a large crumb discharging space for rapid crumb discharging. The cutting force is equally distributed on three cutting edge portions and thus the service life of the drilling bit is relatively improved.

Description

Miniature three blade drill bits

Technical field

The relevant miniature three blade drill bits of the utility model refer to a kind of printed circuit board drilling operation that is used in especially, and it includes drill body part and drill shank, and its drill body part is used for holing on printed circuit board (PCB), and drill shank is then in order to be fixed on the drill bit structure of drilling machine.

Background technology

Bore operation in the printed circuit board (PCB) processing procedure, because being glass fibre and epoxy resin laminated plates two sides or middle pressing Copper Foil, printed circuit board (PCB) forms, basically the resin of material has accounted for overall volume more than 70%, its heat distortion temperature is at 90 ℃ to 150 ℃, if temperature is above 150 ℃ in also promptly holing, drilling cuttings becomes the melting state immediately, and stick together on drill bit and hole wall, be called the glue slag, and the number of glue slag can increase the degree of difficulty of successive process, at present the life-span of drill bit is about (stacking boring together as once with 2 to 4) 1500 to 2000 times, and must in 10 minutes, finish, and drill speed is about 100,000 commentaries on classics, its chisel edge temperature especially up to 300 ℃ to 500 ℃, so the drill bit chip resistance is just more important; For cooperating electronic product towards microminiaturization, thus the size decreases of drill bit the required precision of position, hole is more significantly improved, so that the polarization of drill bit and rigidity also become is even more important.

The employed drill bit of known printed circuit board (PCB), see also Figure 1A, continue to use traditional type two blade drill bit a more, though constantly improve through the dealer, yet its major defect still is: Kong Weiyi partially, bore that body is easily broken, the hole wall quality is bad or the like, still can't effectively improve, this is that two blade drill bit a are subject to its profile, is analyzed as follows:

1. rigidity and chip resistance: see also Figure 1A, 1B, two blade drill bit a bore body b section and slightly are the big and middle little strip in two limits, and for better chip resistance, the thick c of core attenuation thereupon, thus, its rigidity of boring body b just becomes poor more, after sheet material is thrust in apex point d rotation, if bore body b rigidity deficiency, then easily because of apex point d when the cutting, run into the resistance of material internal and fracture, or body b is crooked to cause the hole inclined to one side because of boring.

2. locate: see also Fig. 2 A, 2B, 2C, the culminating point e of two blade drill bit a, it is the joining of two couples of cutting blade face a1 and clearance surface a2 boundary line, it is when making, most drill bit both sides boundary lines is because of boring the slightly difference of body b diameter in the margin of tolerance, and there is not certain joining, form the situation that the two couples of cutting blade face a1 are overlapping with clearance surface a2, separate, and culminating point just can intersection in a bit, so can't reach correct positioning, from the above, two known blade drill bit a have above shortcoming, so be necessary to be improved.

Summary of the invention

Main purpose of the present utility model aims to provide a kind of convenient microbit made from three blade parts, can reach the purpose of quick cutting and chip removal, and can locate and stablize really void shape and the life-span of improving drill bit.

A kind of miniature three blade drill bits, its primary structure includes drill body part and drill shank, wherein drill body part is used for holing on printed circuit board (PCB), drill shank is then in order to be fixed on drilling machine, the drill body part tip grinds to form three cutting faces with same angle, form a crest line in cutting face in twos, and three crest line confluces forms a taper cusp, and the both sides at crest line form blade part and groove respectively, form bigger chip removal space by the blade part and the groove of two opposite faces.

By said structure as can be known, it has three blade parts and the chip removal space is strengthened, can increase the speed of cutting and chip removal,, when rotary cutting, check and balance because of three blade parts are mutually 120 degree, not only less to the rigidity effects of boring body, drill bit can not shake because of cutting resistance, beat, and therefore the hole out of roundness and the hole wall quality of being bored improves relatively, and its stock-removing efficiency increases substantially, find that through experimental test the inclined to one side degree of broken needle and hole reduces more than 80%, and the life-span of drill bit improves relatively many; By bore square on one's body profile view it, it is the structure of one or three fork-shapeds, blade part and groove can be formed with the structure as reinforced ribs, can strengthen the rigidity of drill body part, and when grinding apex point three cutting blades, all adopting same angle grinds, the crest line of its three turnovers can be just in be formed centrally the conical points point, and can not change to some extent, make the location more precisely really because of the difference of boring the body diameter, and when carrying out the operation of abrasive drill, because of the bit cutting face only need be fixed same angle with respect to boring body, make grinding mechanism significantly to simplify, the sharpening operation is more rapid really, unlike two blade bit cutting faces difficulty of two kinds of angle sharpenings operation is arranged, slowly.

Description of drawings

Figure 1A is the end view of conventional construction.

Figure 1B is the vertical view of conventional construction.

Fig. 2 A is the vertical view () of known apex point.

Fig. 2 B is the vertical view (two) of known apex point.

Fig. 2 C is the vertical view (three) of known apex point.

Fig. 3 is a schematic perspective view of the present utility model.

Fig. 4 A is the vertical view of the utility model apex point.

Fig. 4 B is the end view that the utility model bores body.

Fig. 5 A is a chip removal of the present utility model space schematic diagram ().

Fig. 5 B is a chip removal of the present utility model space schematic diagram (two).

The symbol simple declaration

1...... drill bit 10...... drill body part 20...... drill shank

30...... 11...... cutting face, tapering 12...... taper cusp

13...... chip removal space 14...... groove across back 15...... groove width

11a... blade part 11b... groove 11c... crest line

Embodiment

See also Fig. 3,4A, 4B, a kind of miniature three blade drill bits, the primary structure of drill bit 1 includes drill body part 10 and drill shank 20, wherein: drill body part 10 extends a segment distance forward by drill shank 20, because of the round of drill body part and drill shank directly differs a lot of, and be concentrically ringed kenel, so in the confluce of drill body part 10 with drill shank 20, the tapering 30 that one tangible two-part is arranged, as the buffering that absorbs its circle footpath drop, and grind to form three cutting faces 11 with same angle at drill body part 10 tips, cutting face 11 can form a crest line 11c in twos, and three crest line 11c confluces form a taper cusp 12, and form blade part 11a and groove 11b respectively in the both sides of crest line 11c, form bigger chip removal space 13 by the blade part 11a and the groove 11b of two opposite faces.

See also Fig. 5 A, 5B, for chip removal of the present utility model space schematic diagram, if groove across back 14 is more little, it is big that groove width 15 just becomes, so that chip removal space 13 just becomes is big, but relatively blade part 11a will attenuation, machinability will variation, even causes the loss of drill bit 1 easily; And taper cusp 12 is during the closer to the center of circle of whole drill body part 10, its locating effect will be better, and taper cusp 12 depends on three cutting faces, 11 formed crest line 11c, and cutting face 11 can check and balance when the rotary cutting because of being mutually 120 degree, drill bit 1 can not shake because of cutting resistance, beat, therefore the hole out of roundness and the hole wall quality of being bored improves relatively, and when carrying out the operation of abrasive drilling point, because of only there is an angle in drill bit 1 cutting face 11 with respect to drill body part 10, make grinding mechanism significantly to simplify, the sharpening operation is more rapid really.

Make through test, the drill bit 1 that comes out according to the following manner made can reach the speed of accelerating the cutting chip removal, wherein drill body part 10 helical angles of drill bit 1 are that 20 degree are to 45 degree, blade part 11a length is 0.15 to 0.4 times of drill body part 10 diameters, apex point crest line 11c length is 0.1 to 0.3 times of drill body part 10 diameters, drill body part 10 groove widths 15 are 0.5 to 0.8 times of drill body part 10 diameters, and drill body part 10 groove across backs 14 are 0.1 to 0.3 times of drill body part 10 diameters.

In sum, miniature three blade drill bits of the present utility model, by blade part and bigger chip removal space is arranged with three-chip type, really can reach the purpose of quick cutting, chip removal, and, three blade parts check and balance when the rotary cutting because of being mutually 120 degree, increase the life-span of drill bit, also can reach the effect that the location is certain, stablize void shape.

Claims

1. miniature three blade drill bits, its primary structure includes drill body part and drill shank, and wherein drill body part is used for holing on printed circuit board (PCB), and drill shank is then in order to be fixed on drilling machine; It is characterized in that: drill body part is to extend a segment distance forward by drill shank, and confluce at drill body part and drill shank, the tapering that one tangible two-part is arranged, and grind to form three cutting faces with same angle at the drill body part tip, the cutting face forms a crest line in twos, and three crest line confluces form a taper cusp, and form blade part and groove respectively in the both sides of crest line, form bigger chip removal space by the blade part and the groove of two opposite faces.

2. miniature three blade drill bits as claimed in claim 1 is characterized in that: the drill body part helical angle of drill bit is that 20 degree are to 45 degree.

3. miniature three blade drill bits as claimed in claim 1 is characterized in that: the cutting blade minister is 0.15 to 0.4 times of the drill body part diameter.

4. miniature three blade drill bits as claimed in claim 1 is characterized in that: apex point crest line length is 0.1 to 0.3 times of the drill body part diameter.

5. miniature three blade drill bits as claimed in claim 1 is characterized in that: the drill body part groove width is 0.5 to 0.8 times of drill body part diameter.

6. miniature three blade drill bits as claimed in claim 1 is characterized in that: drill body part groove across back is 0.1 to 0.3 times of drill body part diameter.