TW201347880A - Drill structure - Google Patents

Abstract

A drill structure includes two helical flutes formed spirally on the flute part. The two helical flutes are separated at the drill tip, and then approach each other toward the shank part direction. Or the two helical flutes are overlapped on the flute part. The two helical flutes have the first depth and the second depth, respectively, wherein the variations of the first depth and the second depth are different from the drill tip toward the shank part direction. This drill structure has the advantage of high drilling performance.

Description

Drill structure

SUMMARY OF THE INVENTION The present invention relates to a drill bit structure, and more particularly to a drill bit structure having a different depth change rate from a drill tip toward a shank portion for a two-overlap or separate combined chip discharge chute.

The high-density and high-precision line refinement of electronic circuits on printed circuit boards has led to the extensive use of ultra-small-diameter drill bits in the drilling process, and the market is competing for high quality, high demand and rapid supply of printed circuit boards. It is a common expectation and demand to require the drill to achieve high precision, high feed rate, good hole wall quality and unbroken machining conditions in the operation; in order to improve work efficiency and reduce manufacturing costs, on the printed circuit board Through-hole drilling is the process of drilling a number of overlapping printed circuit boards for through-hole drilling, so the longer the drill bit is used, the drill bit needs to have sufficient strength and fast chip removal.

The two cutting edges of the conventional drill bit are mostly provided with a spiral chip discharge groove along the axial direction of the drill bit to discharge the waste cutting edge of the blade along the chip discharge groove, as shown in Fig. 1 as a part of a conventional drill bit. In the cross-sectional view, as shown, the two chip discharge grooves 14, 14' formed on the surface of the drill portion 12 of the drill structure 10 are symmetrically disposed. In the drill structure 10, the two chips are discharged from the grooves 14, 14 'The interlaced spiral is wound, so that the width of the chip discharge grooves 14, 14' is limited, which affects the smoothness of the chip removal, and thus causes the chips to clog between the drill blade portion 12 and the hole wall during the drilling process. , affecting the quality of the hole wall.

On the other hand, the two helical chip discharge grooves 14, 14' looped on the cutting edge portion 12 also cause the thickness of the core of the drill portion 12 to be greatly reduced, which causes the overall rigidity of the drill bit structure 10 to be affected, and At the time of high-speed rotation, the wear and damage of the drill blade portion 12 are accelerated, and the needle breakage problem occurs.

In order to solve the above problems, one of the objects of the present invention is to provide a drill bit structure in which the depth of change of the depth of the dimple discharge grooves from the drill tip toward the shank portion is increased, and the variability of the chip discharge groove of the drill bit structure is increased. The overall rigidity of the drill bit increases the chip space and the chip removal force, thereby improving the accuracy of the drilling to have better drilling performance.

In order to achieve the above object, a drill bit structure according to an embodiment of the present invention includes: a drill shank portion; and a drill blade portion connecting the shank portion, the drill blade portion is provided with a first chip discharge groove and a second chip discharge groove; The first chip discharge groove and the second chip discharge groove extend from a drill tip toward the shank portion, and a core is formed in the center of the drill blade portion, wherein the first chip discharge groove and the second chip discharge groove respectively form a first A depth and a second depth, and a depth change rate of the first depth from the drill tip toward the shank portion is different from a depth change rate of the second depth.

2 is a partial structural view of a drill bit structure according to an embodiment of the present invention, and FIG. 3 is a partial cross-sectional view showing a structure of a drill pin according to an embodiment of the present invention. As shown, the drill bit structure 20 includes a drill handle portion 22 and A drill blade portion 24 is coupled to the shank portion 22, and the drill blade portion 24 is obliquely rearwardly milled by the drill tip 26 with two symmetrical cutting edges 28, and each cutting edge 28 extends along the drill edge portion 24 toward the shank portion 22 to The chip discharge groove is formed by the chisel edge 30 and the two spirals, and a drill core 36 is formed in the center of the drill blade portion 24, and the second chip discharge groove is a first chip discharge groove 32 and a second chip discharge groove 34, respectively, as shown in FIG. It is shown that the first chip discharge groove 32 and the second chip discharge groove 34 are in a state of separation symmetry in the front end portion of the drill tip 26 and the cutting edge portion 24, and the first chip discharge groove extends along the shank portion 22 32 and the second chip discharge groove 34 are gradually combined; wherein the first chip discharge groove 32 and the second chip discharge groove 34 which are gradually combined have a first depth H and a second depth h, respectively, and are drilled toward the drill by the drill tip 26 The first depth of the portion of the first chip discharge groove 32 in the direction of the shank 22 The depth change rate of the degree H and the depth change rate of the second depth h of the partial second chip discharge groove 34 are different.

Following the above description, the drill core 36 disposed at the center of the drill blade portion 24 has a conical shape which is gradually expanded by the drill tip 26 toward the shank portion 22 to form a tapered surface to increase the rigidity of the drill portion 24. In the present invention, the first chip discharge groove 32 and the second chip discharge groove 34 are drilled by changing the first spiral angle of the first chip discharge groove 32 and the second spiral angle of the second chip discharge groove 34. The front portion of the blade portion 24 maintains the symmetrical double groove state, and the rear portion of the cutting edge portion 24 gradually intersects into a groove; in one embodiment, the second spiral angle of the second chip discharge groove 34 has two or more segments. The spiral angle, and the change position of the two-stage or multi-segment spiral inclination angle is not limited to any position of the drill tip 26 to the trailing end of the drill blade portion 24, thereby arbitrarily adjusting the shape of the second chip discharge groove 34 and thus the first chip The discharge grooves 32 are in communication with each other to form a groove. In another embodiment, the spiral angle and shape of the first chip discharge groove 32 and the second chip discharge groove 34 may be adjusted at any position of the cutting edge portion 24 at the same time, so that the drilling edge portion 24 is merged from the symmetric double groove into All the debris is discharged from the ditch.

The first chip discharge groove 32 and the second chip discharge groove 34 intersecting each other in a groove are not limited to overlap each other, and may be adjacent to each other. Please continue to refer to FIG. The first depth H and the second depth h of the first chip discharge groove 32 and the second chip discharge groove 34 are different. In this embodiment, the first depth H is greater than the second depth h, but is not limited thereto. In one embodiment, the first depth H of the first chip discharge groove 32 and the second depth h of the second chip discharge groove 34 are gradually decreased toward the shank portion 22, wherein the depth variation of the first depth H is The rate of change in depth along the tapered depth of the core 36 is greater than the rate of change in depth of the second depth h.

In the present invention, it is not limited to a region in which the depth of change of the first depth and the depth of the second depth is different from the first chip discharge groove and the second chip discharge groove which are gradually combined; in another embodiment, The first chip discharge groove and the second chip discharge groove are overlapped by the drill tip to the end of the cutting edge portion, and the first spiral angle of the first chip discharge groove and the second spiral of the second chip discharge groove are changed The angle between the first chip discharge groove and the second chip discharge groove overlapping portion may be the same, the difference or the overlapping range gradually changes, wherein the first A region in which the depth change rate of the depth is different from the depth change rate of the second depth may be located in the first chip discharge groove and the second chip discharge groove in which the overlapping range gradually changes.

In the present invention, the depth of each of the two chip discharge grooves is different from the depth of the drill tip toward the shank portion, the variability of the chip discharge groove of the drill structure is increased, the overall rigidity of the drill bit is increased, and the chip space and the row are increased. The chip force, which in turn improves the accuracy of the drilling to provide better drilling performance.

The embodiments described above are merely illustrative of the technical spirit and the features of the present invention, and the objects of the present invention can be understood by those skilled in the art, and the scope of the present invention cannot be limited thereto. That is, the equivalent variations or modifications made by the spirit of the present invention should still be included in the scope of the present invention.

10‧‧‧Drill structure

12‧‧‧Drilling

14, 14'‧‧‧ chip discharge ditch

20‧‧‧Drill structure

22‧‧‧Drilling handle

24‧‧‧Drilling

26‧‧‧Drill tip

28‧‧‧ cutting edge

30‧‧‧Corner

32‧‧‧First chip discharge ditch

34‧‧‧Second chip discharge ditch

36‧‧‧ drill core

H‧‧‧First Depth

H‧‧‧second depth

Figure 1 is a partial cross-sectional view showing a conventional drill bit structure.

2 is a partial structural view showing the structure of a drill bit according to an embodiment of the present invention.

3 is a partial cross-sectional view showing the structure of a drill needle according to an embodiment of the present invention.

20‧‧‧Drill structure

24‧‧‧Drilling

26‧‧‧Drill tip

32‧‧‧First chip discharge ditch

34‧‧‧Second chip discharge ditch

36‧‧‧ drill core

H‧‧‧First Depth

H‧‧‧second depth

Claims (10)

A drill bit structure comprising: a drill shank portion; and a drill blade portion connecting the shank portion, the drill blade portion spirally providing a first chip discharge groove and a second chip discharge groove, the first chip discharge The groove and the second chip discharge groove extend from a drill tip toward the shank portion, and a core is formed in the center of the drill blade portion, wherein the first chip discharge groove and the second chip discharge groove respectively form a first a depth and a second depth, and a depth change rate of the first depth from the drill tip toward the shank portion is different from a depth change rate of the second depth. The drill bit structure of claim 1, wherein the first chip discharge groove and the second chip discharge groove are in a separated state at the drill tip, and the first chip is extended toward the shank portion. The discharge groove and the second chip discharge groove are gradually combined. The drill bit structure of claim 2, wherein the region of the depth change of the first depth and the depth change rate of the second depth are located in the first chip discharge groove and the second chip discharge groove which are gradually combined. . The drill bit structure of claim 2, wherein the first chip discharge groove and the second chip discharge groove respectively have a first spiral inclination angle and a second spiral inclination angle, wherein the first spiral inclination angle and the second The change of at least one of the inclination angles of the spiral causes the first chip discharge groove and the second chip discharge groove to be gradually combined. The drill bit structure of claim 1, wherein the first chip discharge groove and the second chip discharge groove are overlapped and formed on the drill edge portion. The bit structure of claim 5, wherein the overlapping range of the first chip discharge groove and the second chip discharge groove gradually changes. The drill bit structure of claim 6, wherein the region of the first depth having a depth change rate different from the depth change rate of the second depth is located in the first chip discharge groove and the first portion of the overlapping range The second chip discharges the groove. The drill bit structure of claim 6, wherein the first chip discharge groove and the second chip discharge groove respectively have a first spiral inclination angle and a second spiral inclination angle, wherein the first spiral inclination angle and the second The change in at least one of the inclination angles of the spiral causes the overlapping range of the first chip discharge groove and the second chip discharge groove to gradually change. The drill bit structure of claim 1, wherein the drill core is tapered from the drill tip toward the shank portion to form a tapered surface, and the first depth or the second depth gradually changes toward the shank portion. small. The bit structure of claim 9, wherein the depth variation of the first depth varies along the tapered surface of the drill core, and the depth variation of the second depth from the drill tip toward the shank portion The rate is greater than the depth change rate of the first depth.