JP3182362U - Drill structure - Google Patents

Abstract

Provided is a drill structure in which a chip accommodating space and a waste power are increased.
A drill structure 20 has a body 24 in which two chip discharge grooves 32 and 34 are spirally installed. The two chip discharge grooves change from the separated state to the combined state from the drill tip 26 toward the shank portion, or the two chip discharge grooves overlap from the drill tip toward the shank portion. Each of the two chip discharge grooves has a first depth H and a second depth h, and the depth change rate of the first depth in the shank portion direction from the drill tip is the second depth. Different from the rate of change in depth. This drill structure has high drill performance.
[Selection] Figure 3

Description

  The present invention relates to a drill structure, and in particular, to a drill structure in which two chip discharge grooves that are overlapped or joined after separation have different depth change rates from the drill tip toward the shank. It is.

  With the development of high-density electronic lines and high-precision line-thinning of printed circuit boards, drilling uses a large number of ultra-small diameter drill bits. Under the competition of high quality, high demand and rapid supply for printed circuit boards in the market, drill bits already meet the requirements of high precision, high feed rate, good hole wall quality and machining conditions that will not break during work. It is a universal demand. In order to improve working efficiency and reduce manufacturing costs, drilling holes in the printed circuit board use multiple stacked printed circuit boards, so a long drill bit is required. Sufficient strength and good waste discharge performance is required.

  Chips generated from the two cutting edges of the conventional drill bit are directed in the axial direction of the drill bit along the spiral chip discharge groove, and the chips are discharged out of the chip discharge groove. FIG. 1 is a partial cross-sectional view of a conventional drill bit. As shown in the drawing, the two chip discharge grooves 14 and 14 ′ formed on the surface of the body 12 of the drill structure 10 are installed symmetrically. In the drill structure 10, the two chip discharge grooves 14 and 14 are formed. 'Because of the symmetrical spiral state, the width of the chip discharge grooves 14, 14' is limited, which affects the chip discharge performance. Affects hole wall quality.

  Further, if the two spiral chip discharge grooves 14 and 14 ′ formed on the body 12 are made large, the thickness of the core thickness inside the body 12 is greatly reduced, so that the overall rigidity of the drill structure 10 is increased. In addition to being affected, at the time of high speed rotation, the wear and damage of the body 12 are accelerated, and the needle is easily broken.

  In order to solve the above-mentioned problems, the present invention provides a drill structure, and the variability of the chip discharge groove of the drill structure is determined by the difference in depth change rate from the drill tip to the shank portion of the two chip discharge grooves. The purpose of this is to increase the rigidity and strength of the entire drill bit, increase the chip accommodating space and waste power, improve the precision of the drill, and achieve excellent drill performance.

  To achieve the above object, a drill structure according to a preferred embodiment of the present invention includes a shank portion and a body connected to the shank portion. The body is spirally installed 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 the tip of the drill to the shank, and have a core thickness in the center of the body. Is forming. The first scrap discharge groove and the second chip discharge groove have a first depth and a second depth, respectively, and the depth change rate of the first depth from the drill tip to the shank portion is second. It differs from the depth change rate of the depth.

  The drill structure of the present invention increases the variability of the chip discharge groove of the drill structure due to the difference in the depth change rate of the shank from the drill tip at each depth of the two chip discharge grooves, and the rigidity of the drill as a whole And increase the waste space and waste power, improve the accuracy of the drill and achieve excellent drill performance.

It is a partial cross section figure of the conventional drill structure. It is a figure which shows the partial structure of the drill structure by the preferable aspect of this invention. 1 is a partial cross-sectional view of a drill bit structure according to a preferred embodiment of the present invention.

  FIG. 2 is a diagram showing a partial structure of a drill structure according to a preferred embodiment of the present invention, and FIG. 3 is a partial cross-sectional view of a drill bit structure according to a preferred embodiment of the present invention. As shown in the figure, the drill structure 20 includes a shank portion 22 and a body 24 connected to the shank portion 22. The body 24 polishes two symmetrical cutting blades 28 obliquely backward from the drill tip 26, and each cutting blade 28 extends along the body 24 in the direction of the shank portion 22, A land 30 and two spiral chip discharge grooves are formed, and a core thickness 36 is formed at the center of the body 24. The two chip discharge grooves are the first chip discharge groove 32 and the second chip discharge groove 34, respectively, and as shown in FIG. 3, the first chip discharge groove 32 and the second chip discharge groove 34 are The drill tip 26 and the front stage portion of the body 24 are in a state of separation symmetry and extend in the direction of the shank portion 22 so that the first chip discharge groove 32 and the second chip discharge groove 34 are gradually coupled. Two gradually connecting first and second chip discharge grooves 32 and 34 each have a first depth H and a second depth h, and extend from the drill tip 26 toward the shank portion 22. The depth change rate of the first depth H of the first scrap discharge groove 32 is different from the depth change rate of the second depth h of the second chip discharge groove 34.

  The core thickness 36 installed in the center of the body 24 is conical and gradually expands from the drill tip 26 to the shank portion 22 to form a conical core thickness taper, thereby increasing the rigidity strength of the body 24. Yes. In the present invention, 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 body of the first chip discharge groove 32 and the second chip discharge groove 34 is changed. The front stage of 24 is maintained in a symmetrical two-groove state, and the rear stage of the body 24 gradually becomes one groove. In a preferred embodiment, the second helix angle of the second chip discharge groove 34 has a two-stage or multi-stage helix angle, and the conversion position of the two-stage or multi-stage helix angle is changed from the drill tip 26 to the body. The position is not limited to the position of the 24 terminal, and by arbitrarily adjusting the shape of the second chip discharge groove 34, it is connected to the first chip discharge groove 32 to form one groove. In another preferred embodiment, at any position of the body 24, the spiral angle and shape of the first chip discharge groove 32 and the second chip discharge groove 34 are adjusted so that the body 24 can be separated from two symmetrical grooves. It can be merged with the waste discharge groove.

  The first chip discharge groove 32 and the second chip discharge groove 34 connected to one groove are not limited to being overlapped with each other, and may be adjacent to each other, as shown in FIG. The first depth H and the second depth h which the chip discharge groove 32 and the second chip discharge groove 34 respectively have are different. In this aspect, the first depth H is larger than the second depth h. It is not limited. In a preferred embodiment, the first depth H of the first chip discharge groove 32 and the second depth h of the second chip discharge groove 34 gradually decrease in the direction of the shank portion 22, and the depth of the first depth H. The change changes along a conical core thickness taper having a core thickness of 36, and the depth change rate of the second depth h is larger than the depth change rate of the first depth H.

  In the present invention, the regions where the depth change rates of the first depth and the second depth are not different are not limited to being in the first and second chip discharge grooves that are gradually combined. In another preferred embodiment, the first scrap discharge groove and the second chip discharge groove at the end of the body from the drill tip overlap, and the first spiral angle of the first scrap discharge groove and the second of the second chip discharge groove By changing the helix angle, the overlapping portion of the first chip discharge groove and the second chip discharge groove may be the same, different, or the range may gradually change, and the depth of the first depth The areas where the depth change rate and the depth change rate of the second depth are different are located in the first chip discharge groove and the second chip discharge groove where the overlapping range gradually changes.

  In the present invention, due to the difference in the rate of change in the depth of the shank from the tip of the drill at each depth of the two chip discharge grooves, the variability of the chip discharge groove of the drill structure is increased and the rigidity of the entire drill is improved. And, the waste space and waste power are increased, the precision of the drill is improved, and excellent drill performance is achieved.

  In the present invention, the preferred embodiments have been disclosed as described above. However, these embodiments are not limited to the present invention, and any person who is familiar with the technology can make various modifications within the spirit and scope of the present invention. Therefore, the protection scope of the present invention is based on the contents specified in the claims of the utility model.

DESCRIPTION OF SYMBOLS 10 Drill structure 12 Body 14, 14 'Chip discharge groove 20 Drill structure 22 Shank part 24 Body 26 Drill tip 28 Cutting blade 30 Land 32 First scrap discharge groove 34 Second chip discharge groove 36 Core thickness H First depth h Second depth

Claims (10)

A drill structure,
Shank part,
It is connected to the shank part, and the first scrap discharge groove and the second chip discharge groove are installed spirally, the first scrap discharge groove and the second chip discharge groove extend from the tip of the drill to the shank part, And a body forming a core thickness at the center of the body;
Including
The first chip discharge groove and the second chip discharge groove form a first depth and a second depth, respectively, and the depth change of the first depth from the drill tip toward the shank portion. The drill structure according to claim 1, wherein a rate is different from a depth change rate of the second depth.   The first chip discharge groove and the second chip discharge groove are separated from each other at the tip of the drill, and extend to the shank portion. The first chip discharge groove and the second chip discharge groove are The drill structure according to claim 1, wherein the drill structure is gradually joined.   The regions where the depth change rate of the first depth and the depth change rate of the second depth are different are in the first chip discharge groove and the second chip discharge groove that are gradually combined. The drill structure according to claim 2.   Each of the first chip discharge groove and the second chip discharge groove has a first twist angle and a second twist angle, respectively, and the at least one change of the first twist angle and the second twist angle The drill structure according to claim 2, wherein the first chip discharge groove and the second chip discharge groove are gradually coupled.   2. The drill structure according to claim 1, wherein the first chip discharge groove and the second chip discharge groove are formed to overlap the body. 3.   6. The drill structure according to claim 5, wherein the overlapping range between the first chip discharge groove and the second chip discharge groove gradually changes.   The region where the depth change rate of the first depth is different from the depth change rate of the second depth is in the first chip discharge groove and the second chip discharge groove in which the overlapping range gradually changes. The drill structure according to claim 6, wherein:   Each of the first chip discharge groove and the second chip discharge groove has a first twist angle and a second twist angle, and changes at least one of the first twist angle and the second twist angle. The drill structure according to claim 6, wherein an overlapping range of the first chip discharge groove and the second chip discharge groove gradually changes.   The drill structure according to any one of claims 1 to 8, wherein the core thickness gradually spreads from the tip of the drill to the shank portion to form a conical core thickness taper.   The drill structure according to any one of claims 1 to 9, wherein the first depth or the second depth gradually decreases in the direction of the shank portion.