TWM456238U - Drill structure - Google Patents

Abstract

A drill structure includes a flute part and a shank part. The flute part is arranged at one end of the shank part. Two helical grooves are formed on the outer surface of the flute part to form two helical cutting edges. Two helical cutting edges comprise a front section, a middle section and a rear section. The diameter of the front section is longer than the diameter of the rear section. The middle section is connected to the rear section and the front section. A clearance structure is arranged at the front section. The length of the clearance structure is less than the length of the front section.

Description

Drill structure

The present invention relates to a drill bit structure, and in particular to a bit structure in which the length of the clearance structure is smaller than the length of the drill section in the preceding section.

Figure 1 is a schematic view of a conventional drill bit structure, as shown, the surface of the drill blade 2 of the drill 1 is formed with a spiral chip discharge groove 4 and a spiral chisel edge 6 between the chip discharge groove 4; The front end region 2a of the drill blade portion 2 which is in contact with the inner wall of the machining hole when the drill bit 1 is drilled is interposed between the tip end 8 of the drill blade portion 2 and a step 10 which reduces the outer diameter of the drill blade portion 2, and the front end The helical chisel edge 6 of the zone 2a is provided with a clearance structure 12 over the step 10 such that the length of the clearance structure 12 is greater than the length of the front end zone 2a. Such an excessively long clearance structure 12 makes the area of the surface of the spiral lateral edge 6 of the front end region 2a contact hole wall relatively small, and it is easy to cause the hole diameter of the hole to be insufficient due to the rapid decrease of the outer diameter of the wear, thereby affecting the processing quality of the hole.

In order to solve the above problems, one of the purposes of the present invention is to provide a drill bit structure in which the length of the clearance structure formed on the spiral side edge is smaller than the length of the front drilled diameter area to improve the problem of insufficient borehole diameter.

In order to achieve the above object, the drill bit structure of an embodiment of the present invention comprises: a drill handle portion and a drill edge portion. The drilling edge portion is disposed at one end of the shank portion, and the outer surface of the drilling edge portion is provided with two spiral grooves to form a two-spiral side edge, and the spiral side edge includes a front drilling diameter section, a length difference connecting section and a rear section drilling diameter zone. The outer diameter of the front section of the drilled section is larger than the outer diameter of the trailing section of the drilled section, and the front section of the drilled section and the rear section of the drilled section are connected by the stepped connection zone, and the diameter of the spiral side edge is drilled before The zone is provided with a clearance structure, and the length of the clearance structure is smaller than the length of the drilled section of the front section.

In the following, the specific embodiments and the accompanying drawings are explained in detail, and it is easier to understand the purpose, technical content, characteristics and effects achieved by the present invention.

2 is a schematic view showing the structure of the drill bit according to the first embodiment of the present invention. As shown, a drill bit structure 20 includes a drill shank portion 22 and a drill blade portion 24 is disposed at one end of the shank portion 22, and the drill edge portion The outer surface of the 24 is provided with two spiral grooves 26 to form a two-helical side edge 28. The spiral side edge 28 includes a front section of the drilled area A ₁ , a section of the differential connection area A ₂ and a rear section of the drilled area A ₃ , and the front section of the drilled section The outer diameter D _{1 of} A ₁ is larger than the outer diameter D _{3 of the} rear section diameter area A ₃ , and the front section diameter area A ₁ and the rear section diameter area A ₃ are connected by the step difference connection area A ₂ , and the front section diameter area A _{1 is} set structure clearance 30, the clearance 30 is smaller than the overall length L of the length a ₁ preceding the drill diameter region L.

Please refer to FIG. 2, the length of the line preceding the bore path area A ₁ is drilled from 3 to 30% of the entire length of the blade portion 24, a clearance 28 is a front end structure 30, 28 is provided from the back side of the blade along a helical coil side edges, since The length L of the front section of the drilled hole area A ₁ is larger than the length l of the clearance structure 30, and at the end of the front section of the drilled section A ₁ (near the step difference connection area A ₂ ), a portion of the drill bit is resistant to the outer diameter wear. The area, which is the length of the clearance structure 30 (the difference between L and l) of the front drilled hole area A ₁ , can improve the problem of insufficient borehole diameter.

Wherein, the step connection area A ₂ is a slope structure 32 connecting the front section of the drilled section A ₁ and the rear section of the drilled section A ₃ such that the outer diameter D _{1 of} the front section of the drilled section A ₁ is inclinedly retracted via the inclined structure 32 The outer diameter D ₃ of the drilled-diameter area A ₃ and the oblique angle θ ₂ of the inclined surface structure 32 are between 10 degrees and 90 degrees. In addition, the outer diameter D _{1 of the} front section diameter area A ₁ is larger than the outer diameter D _{3 of the} rear section diameter area, so that when drilling, there is a large gap between the rear section diameter area A ₃ and the hole wall, which can improve the drilling time. Chip removal capacity. It should be noted that the length of the clearance structure 30 of FIG. 2 and the length of the front section of the drilled section A _{1 are} for illustrative purposes only and do not represent the actual ratio of the drill bit structure. In the first embodiment described above, the two spiral grooves 26 each have a fixed and identical helical inclination angle θ ₁ , and the angle of the helical inclination angle θ ₁ is between 20 degrees and 60 degrees.

3 shows the drill bit structure of the second embodiment of the present invention. As shown, the drill bit structure 20 includes a drill shank portion 22 and a drill blade portion 24, and the drill blade portion 24 is disposed at one end of the shank portion 22, The cutting edge portion 24 includes a tip end portion 24a, an intermediate portion 24b and a body portion 24c. The outer surface of the cutting edge portion 24 is provided with two spiral grooves 26 to form a two-spiral side edge 28, and the two spiral grooves 26 are at the tip end portion. 24a is symmetrically separated; the helical inclination angle of the two spiral grooves 26 of the intermediate portion 24b is not limited to a fixed angle, and one or both of the two spiral grooves 26 have a variable helix angle, and the angle of the variable helix angle can be The variation between 10 degrees and 80 degrees causes the two spiral grooves 26 to gradually approach the intermediate portion 24b until the body segments 24c merge the two spiral grooves 26. In the second embodiment, the diameter difference based on side edge 28 of the helical drill also has a front portion bore path area A _1, A ₁ is the length of the drill diameter anterior region length L is less than or equal to the tip section 24a of S. The front section diameter area A _{1 is} provided with a clearance structure 30, and the length l of the clearance structure 30 is smaller than the length L of the front section diameter area A ₁ .

In the first embodiment and the second embodiment, the front end of the cutting edge portion 24 shown in FIG. 2 and FIG. 3 forms a blade surface structure 40. As shown in FIG. 4, the blade surface structure 40 includes: two main blades 42 and The two flank faces 43 are symmetrically disposed on one of the cutting edge portions 24 of the cutting edge portion 24 for cutting the surface of the workpiece by the blade surface structure 40. The front end of the cutting edge portion 24 still has the clearance structure 30 backward. It is disposed along the spiral side edge 28 (please refer to the first and second embodiments). On the other hand, the outer surface of the drill blade portion 24 may be coated with a coating layer (not shown), which is made of a metal compound, a carbon compound or a mixture of the above components, and preferably nitrogen. Titanium (TiN), TiAlN, Diamond Coating or Diamond like Coating. Further, the drill blade portion 24 and the shank portion 22 may be integrally formed of a tungsten carbide bar, or may be a tungsten carbide material shank portion 22 and a tungsten carbide material drilled by welding or an adhesive. The blade portions 24 are joined together, or the shank portion 22 made of stainless steel and the blade portion 24 made of tungsten carbide are joined together by means of welding or adhesion.

Following the above, the cutting edge portion 24 can be inserted into the shank portion 22 in a manner other than welding or adhesive bonding, and in one embodiment, is disposed on one end surface of the shank portion 22. An inner hole (not shown), and one end of the cutting edge portion 24 has an insertion end (not shown), the inner diameter of the inner hole is less than or equal to the outer diameter of the insertion end, and the difference is between 0 Between micrometers (μm) and 30 micrometers, the insertion end of the cutting edge portion 24 is press-fitted into the inner hole of the shank portion 22, so that the cutting edge portion 24 and the shank portion 22 are combined.

In summary, the length of the drilled-diameter area in the front section of the spiral side blade is larger than the length of the clearance structure, and provides a large wear area when the drill blade rotates the wear hole wall, so that the outer diameter of the wear is not shortened rapidly. This leads to a problem of insufficient borehole diameter, which in turn improves the processing quality of the hole.

The embodiments described above are only for explaining the technical idea and characteristics of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement them according to the scope of the patent. That is, the equivalent changes or modifications made by the people in accordance with the spirit revealed by this creation should still be covered by the scope of the patent of this creation.

1‧‧‧ drill bit

2‧‧‧Drilling

2a‧‧‧ front end area

4‧‧‧chip discharge ditch

6‧‧‧Spiral chisel

8‧‧‧ tip

10 ‧ ‧ paragraph difference

12‧‧‧ clearance structure

20‧‧‧Drill structure

22‧‧‧Drilling handle

24‧‧‧Drilling

24a‧‧‧ tip section

24b‧‧‧ middle section

24c‧‧‧ body section

26‧‧‧Spiral groove

28‧‧‧Spiral side blade

A1‧‧‧ front section

A2‧‧ ‧ section connection area

A3‧‧‧Deep section

D ₁ , D ₃ ‧‧‧ OD

30‧‧‧ clearance structure

l, L, S‧‧‧ length

32‧‧‧Bevel structure

θ ₁ ‧‧‧spiral dip

θ ₂ ‧‧‧ bevel

40‧‧‧Knife structure

41‧‧‧The tip of the knife is quiet

42‧‧‧Major face

43‧‧‧Sub-blade

Figure 1 is a schematic view showing a conventional structure of a drill bit.

Figure 2 is a schematic view showing the drill bit structure of the first embodiment of the present invention.

Fig. 3 is a schematic view showing the drill bit structure of the second embodiment of the present invention, in which spiral grooves are gradually approached and merged.

Fig. 4 is a schematic view showing the flank structure of an embodiment of the present invention.

20‧‧‧Drill structure

22‧‧‧Drilling handle

24‧‧‧Drilling

26‧‧‧Spiral groove

28‧‧‧Spiral side blade

A1‧‧‧ front section

A2‧‧ ‧ section connection area

A3‧‧‧Deep section

D ₁ , D ₃ ‧‧‧ OD

30‧‧‧ clearance structure

l, L‧‧‧ length

32‧‧‧Bevel structure

θ ₁ ‧‧‧spiral dip

θ ₂ ‧‧‧ bevel

Claims (14)

A drill bit structure comprising: a drill shank portion and a drill blade portion disposed at one end of the shank portion, the outer surface of the drill blade portion is provided with two spiral grooves to form a two-spiral side edge, the spiral side edge comprising a front section of the drilled section, a section of the differential connection zone and a rear section of the drilled section, wherein the outer diameter of the drilled section of the front section is larger than the outer diameter of the drilled section of the rear section, and the diameter of the front section and the rear section of the drilled section are The connection zone is connected, and the front section of the spiral side edge is provided with a clearance structure, and the length of the clearance structure is smaller than the length of the drill section of the front section. The drill bit structure of claim 1, wherein the stepped connection zone is a beveled structure, and the outer diameter of the front section of the drilled section is retracted to the outer diameter of the rear section of the drilled section. The bit structure of claim 2, wherein the bevel structure has an oblique angle between 10 and 90 degrees. The bit structure of claim 1, wherein the clearance structure is disposed along the spiral side edge from the front end of the spiral side edge. The drill bit structure of claim 1, wherein the length of the front section of the drilled section is 3% to 30% of the length of the drill section. The drill bit structure of claim 1, wherein the front end of the cutting edge portion forms a flank structure, and the flank structure comprises two main flank surfaces and two flank surfaces symmetrically disposed at one of the cutting edge portions. The drill bit structure of claim 1, wherein the spiral groove has a fixed helical inclination angle of between 20 and 60 degrees. The drill bit structure of claim 1, wherein the spiral groove has a variable helix angle, the angle of the helix angle being between 10 and 80 degrees. The drill bit structure of claim 8, wherein the cutting edge portion comprises a tip end segment, an intermediate segment and a body segment, wherein the spiral groove is symmetrically separated from the tip end segment, and the spiral groove is The middle section is gradually approaching and merged together in the body section. The bit structure of claim 9, wherein the length of the front section of the drilled section is less than or equal to the length of the tip section. The drill bit structure of claim 1, wherein the shank portion and the drill edge portion are integrally formed by a tungsten carbide bar. The drill bit structure of claim 1, wherein the shank portion is made of stainless steel, the material of the drill portion is tungsten carbide, and the shank portion and the drill portion are joined by welding or adhesive. together. The drill bit structure of claim 1, wherein an end surface of one end of the drill shank portion is provided with an insertion end having an insertion end having an inner diameter smaller than or equal to an outer diameter of the insertion end, And inserting the insertion end into the inner hole, wherein a difference between an inner diameter of the inner hole and an outer diameter of the insertion end is between 0 micrometers (μm) and 30 micrometers. The drill bit structure according to claim 1, wherein the outer surface of the drill blade portion is coated with a coating layer made of a metal compound, a carbon compound or a mixture of the above components.