CN204053023U

CN204053023U - Drill bit structure

Info

Publication number: CN204053023U
Application number: CN201420350793.5U
Authority: CN
Inventors: 邱世峰; 简松豪; 赵铭元
Original assignee: TCT GLOBAL Ltd
Current assignee: TCT GLOBAL Ltd
Priority date: 2013-08-13
Filing date: 2014-06-27
Publication date: 2014-12-31
Anticipated expiration: 2024-06-27
Also published as: TWM485776U

Abstract

The utility model provides a drill bit structure, the knife face center both sides slant backward of its cutting part section foremost is formed with the cutting knife face of bisymmetry, each cutting knife face contains a cutting limit, a back of the body limit and an outer fringe limit, the outer fringe is following the outer peripheral face of cutting part and is extending around in order to form two spiral side edges and two rows of bits ditches backward, and the cutting limit of each cutting knife face and the back of the body limit of another cutting knife face constitute the leading edge of the wall of a bits discharge ditch, wherein the part back of the body limit at the neighbouring knife face center of the part cutting limit of the neighbouring knife face of each cutting knife face and another cutting knife face forms a main recess jointly and extends to the wall of bits discharge ditch, the well section portion of each cutting limit forms a recess again and extends to the wall of bits discharge ditch. The design of the discontinuous straight cutting line of the cutting edge can increase the cutting capacity of the drill bit and avoid the chips from being rolled at the tail end of the blade section in a lump shape.

Description

Drill bit structure

Technical Field

The present invention relates to a drill structure (drill structure), and more particularly, to a drill structure suitable for a Printed Circuit Board (PCB).

Background

With the development of technology, the conductive lines on the printed circuit board are gradually thinning towards high density and high precision. In order to meet the high competitive environment of the market for high quality, high demand and fast supply of printed circuit boards, the requirements of the industry for the precision, strength and feed rate of micro drills (micro drill) used in the drilling process of printed circuit boards, even the quality of hole walls, and other processing conditions are also increasing. In addition, in practice, the same drilling process is usually performed on a plurality of stacked printed circuit boards to improve the processing efficiency and reduce the manufacturing cost, so that the drill used has a long length and must have sufficient strength and chip removal capability.

The conventional micro drill bit has two symmetrical cutting faces 12 formed obliquely backward from two sides of a center 10 of the cutting face, as shown in fig. 1, each cutting face 12 includes a cutting edge 121, a back edge 122 and an outer edge 123, wherein the cutting edge 121 is in a continuous straight line shape, and the total length l of the cutting line of the cutting edge 121 is short due to the continuous straight line shape, so that the cutting capability is weak, and the chips are not easily broken by the continuous straight line shape cutting line, and the chips are easily rolled on the end of the drill bit edge in a lump shape.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problem, the utility model aims at providing a drill bit structure, the design of main recess and inferior recess on the cutting edge through the cutting knife face for the line of cut total length of cutting knife face increases, and then increases the smear metal ability of drill bit, and this kind of discontinuous straight line of cut can be with the chip fragmentation, avoids the smear metal to become the bulk and rolls up on the tip of cutting part section, and then improves the drilling quality of this drill bit structure.

In order to achieve the above object, the utility model provides a drill bit structure contains: a stalk section and an edge section, this edge section sets up in the one end of stalk section, the foremost end of edge section sets up a knife face center, knife face center both sides slant backward is formed with the cutting knife face of bisymmetry, each cutting knife face contains a cutting edge, a back of the knife limit and an outer fringe limit, the outer fringe border is extending backward around in order to form two spiral side edges and two rows of bits ditches along the outer peripheral face of edge, and the cutting edge of each cutting knife face and the back of the knife limit of another cutting knife face constitute the leading edge of the wall of a chip removal ditch, wherein each the part at the neighbouring knife face center of cutting knife face the cutting edge and another the part at the neighbouring knife face center of cutting knife face the back of the knife edge forms a main groove jointly and extends to the wall of chip removal ditch, and two main grooves are symmetrical in the center, the middle part of each cutting edge forms a recess and extends to the wall of knife face again, and the two grooves are symmetrical to the center of the knife face.

The drill bit structure as described above, wherein a portion of the outer edge forms a clearance groove along the spiral flank, each cutting blade face includes a primary blade face and a secondary blade face, wherein the secondary blade face has the clearance groove and the clearance groove penetrates to the back edge.

The drill bit structure as described above, wherein the depth of the minor groove accounts for 30% to 80% of the width of the major rake face, and the thickness of the rake face center accounts for 10% to 70% of the width of the major rake face.

The drill bit structure as above, wherein, the length of blade section is 5 millimeters to 18 millimeters, the main recess extends the length of the wall of chip removal ditch is 1 millimeter to 8 millimeters, the secondary recess extends the length of the wall of chip removal ditch is 1 millimeter to 8 millimeters.

The drill bit structure as described above, wherein the outer diameter of the shank section is 3.15 mm to 3.20 mm, and the outer diameter of the blade section is 1 mm to 10 mm.

The drill bit structure as described above, wherein the distance between the secondary groove on the cutting edge and the outer rim is 5% to 20% of the outer diameter of the blade section.

The drill bit structure as described above, wherein the opening width of the secondary groove on the cutting edge occupies 3% to 30% of the outer diameter of the blade section.

The drill bit structure as described above, wherein the opening width of the primary flutes accounts for 10% to 50% of the outer diameter of the blade section.

The drill bit structure as described above, wherein the shank section is a tungsten carbide or stainless steel shank section, the blade section is a tungsten carbide blade section, and the shank section and the blade section are bonded by an adhesive or by welding.

The drill bit structure as described above, wherein the shank section and the blade section are integrally formed by a tungsten carbide rod.

The utility model discloses an advantage of drill bit structure is, the design of main recess and inferior recess on the cutting edge through the cutting knife face for the line of cut total length of cutting knife face increases, and then increases the smear metal ability of drill bit, and this kind of discontinuous straight line of cut line can be with the chip fragmentation, avoids the smear metal to become the bulk and rolls up on the tip of cutting part section, and then improves the drilling quality of this drill bit structure.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein,

fig. 1 is a front view showing a structure of a conventional drill.

Fig. 2 is an external view of a drill structure according to an embodiment of the present invention.

Fig. 3 is a front view of a drill bit according to an embodiment of the present invention.

Main element number description:

center of 10 blade face

12 cutting blade face

121 cutting edge

122 knife back edge

123 outer edge

length l

20 drill bit structure

22 shank segment

24 blade section

26 center of blade face

28 first cutting plane

281 first cutting edge

282 first knife back edge

283 first outer edge

30 second cutting blade face

301 second cutting edge

302 second knife back edge

303 second outer edge

32. 32' helical side edge

34. 34' chip removal ditch

36. 36' main groove

38. 38' minor groove

40. 40' side gap groove

42 major blade face

44 minor face

d depth

Width W

Thickness of T

L1, L2 Length

Distance S

w1, w2 opening width

A end point

B endpoint

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings. The following detailed description of the preferred embodiments is provided for illustrative purposes only and is not intended to limit the invention.

Referring to fig. 2, which is an external view of a drill structure according to an embodiment of the present invention, fig. 3 is a front view of a drill structure according to an embodiment of the present invention, as shown in fig. 2, the drill structure 20 includes a shank section 22 and a blade section 24, the blade section 24 is connected to one end of the shank section 22, a cutting face center 26 is disposed at the frontmost end of the blade section 24, and referring to fig. 3, two symmetrical cutting faces are obliquely formed backward at both sides of the cutting face center 26, which are respectively a first cutting face 28 and a second cutting face 30, the first cutting face 28 includes a first cutting edge 281, a first back edge 282 and a first outer edge 283, the second cutting face 30 includes a second cutting edge 301, a second back edge 302 and a second outer edge 303, the first outer edge 283 and the second outer edge 303 respectively extend backward along the outer peripheral surface of the blade section 24 (shown in fig. 2) to form two spiral side edges 32, 32 ' and two flutes 34, 34 ', and the first cutting edge 281 of the first cutting face 28 and the second back edge 302 of the second cutting face 30 form a leading edge of a wall surface of one flute 34, and correspondingly, the second cutting edge 301 of the second cutting face 30 and the first back edge 282 of the first cutting face 28 form a leading edge of a wall surface of the other flute 34 ', wherein a portion of the first cutting edge 281 and a portion of the second back edge 302 adjacent to the face center 26 jointly form a main groove 36, the main groove 36 extends to the wall surface of the flute 34, and correspondingly, a portion of the second cutting edge 301 and a portion of the first back edge 282 adjacent to the face center 26 jointly form a main groove 36 ', the main groove 36 ' extends to the wall surface of the flute 34 ', and the two main grooves 36, 36 ' are symmetrical to the face center 26; the first and second cutting edges 281 and 301 have first and second grooves 38 and 38 ' formed at the middle portions thereof, respectively, the first and second grooves 38 and 38 ' extend to the wall surfaces of the chip grooves 34 and 34, respectively, and the first and second grooves 38 and 38 ' are symmetrical with respect to the center 26 of the rake surface.

As described above, referring to fig. 2 and 3, a clearance groove 40, 40 ' is respectively formed on a portion of the first outer edge 283 and a portion of the second outer edge 303 along the spiral side edge 32, 32 ', so that the first cutting tool surface 28 and the second cutting tool surface 30 are respectively divided into a main tool surface 42 and a secondary tool surface 44, wherein the two secondary tool surfaces 44 respectively have the clearance groove 40, 40 ' on the outer edge and respectively penetrate to the first back edge 282 and the second back edge 302.

The depth d of the minor grooves 38, 38' on the first cutting edge 281 and the second cutting edge 301 accounts for 30% to 80% of the width W of the major rake face 42, and the thickness T of the rake face center 26 accounts for 10% to 70% of the width W of the major rake face 42.

In one embodiment, the blade section 24 has a length of 5 millimeters (mm) to 18 mm, and as shown in FIG. 2, the primary groove 36 extends along the wall for a length L1 of 1 mm to 8 mm, and the secondary groove 38 extends along the wall for a length L2 of 1 mm to 8 mm.

In one embodiment, the outer diameter of the shank section 22 is 3.15 to 3.20 mm, and the outer diameter of the blade section 24 is 1 mm to 10 mm. The distance S between the minor grooves 38, 38' of the first cutting edge 281/second cutting edge 301 and the first/second peripheral edges 283, 303 of the major rake face 42 is 5% to 20% of the outer diameter of the blade section 24; the opening width w1 of the secondary grooves 38, 38 'is again between 3% and 30% of the outer diameter of the blade section 24, while the opening width w2 of the primary grooves 36, 36' is between 10% and 50% of the outer diameter of the blade section 24.

On the other hand, the shank section 22 is made of tungsten carbide or stainless steel, the blade section 24 is made of carbide, such as tungsten carbide, and the shank section 22 and the blade section 24 are bonded by adhesive or welding. Alternatively, the shank section 22 and the blade section 24 are integrally formed of tungsten carbide rod.

In the present invention, by the design of the primary grooves 36, 36 'and the secondary grooves 38, 38', the total length of the cutting line of the first cutting blade surface 28 and the second cutting blade surface 30 is longer than the total length l (shown in fig. 1) of the known cutting line, as shown in fig. 3, taking the first cutting blade surface 28 as an example, the total length of the cutting line, that is, the length of the cutting edge between the end point a and the end point B, is longer than the total length l of the known cutting line, so as to increase the cutting capability of the drill, and the discontinuous straight cutting line can reduce the chips, prevent the chips from being rolled up at the end of the blade section in a lump, and further improve the drilling quality of the drill structure.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention. Moreover, it should be noted that the components of the present invention are not limited to the above-mentioned integral application, and various technical features described in the present invention can be selected to be used alone or in combination according to actual needs, so that the present invention naturally covers other combinations and specific applications related to the invention of the present invention.

Claims

1. A drill bit structure, comprising:

a shank section; and

an edge section, set up in the one end of stalk portion section, the foremost end of edge section sets up a knife face center, knife face center both sides slant backward is formed with the cutting knife face of bisymmetry, each cutting knife face contains a cutting limit, a back of the body limit and an outer fringe limit, the outer fringe is following the outer peripheral face of edge section extends backward and winds around in order to form two spiral side edges and two rows of bits ditches, and each cutting knife face cutting limit and another cutting knife face the back of the body limit constitutes one the leading edge of the wall of bits ditches, wherein each the neighbouring of cutting knife face the part at knife face center cutting limit and another the neighbouring of cutting knife face the part at knife face center the back of the body limit forms a main recess jointly and extends to the wall of bits ditches, and two main recess symmetry in the knife face center, each again the well subsection of cutting limit forms a recess and extends to the wall of bits ditches, and the two secondary grooves are symmetrical to the center of the knife face.

2. The drill bit structure of claim 1, wherein a portion of the outer rim forms a clearance groove along the helical side edge, each cutting face comprising a major face and a minor face, wherein the minor face has the clearance groove and the clearance groove extends through to the back edge.

3. The drill bit structure of claim 2, wherein the depth of the minor groove is 30% to 80% of the width of the major rake face and the thickness of the center of the rake face is 10% to 70% of the width of the major rake face.

4. The drill bit structure of claim 1, wherein the blade section has a length of 5 mm to 18 mm, the primary groove has a length extending along the wall of the chip evacuation channel of 1 mm to 8 mm, and the secondary groove has a length extending along the wall of the chip evacuation channel of 1 mm to 8 mm.

5. The drill bit structure of claim 1, wherein the shank section has an outer diameter of 3.15 mm to 3.20 mm and the blade section has an outer diameter of 1 mm to 10 mm.

6. The drill bit structure of claim 1, wherein the secondary flutes on the cutting edge are located between 5% and 20% of the outer diameter of the blade section from the outer rim.

7. The drill bit structure of claim 1, wherein the opening width of the secondary flutes on the cutting edge is between 3% and 30% of the outer diameter of the blade section.

8. The drill bit structure of claim 1, wherein the opening width of the primary groove is 10% to 50% of the outer diameter of the blade section.

9. The drill bit structure of claim 1, wherein the shank section is a tungsten carbide or stainless steel shank section, the blade section is a tungsten carbide blade section, and the shank section and the blade section are bonded by an adhesive or by welding.

10. The drill bit structure of claim 1, wherein the shank section and the blade section are integrally formed from a tungsten carbide rod.