JP2920334B2 - Blank material for drill manufacturing and method of manufacturing drill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blank material for manufacturing a drill having a twisted edge (blank material for manufacturing a drill) and a drill manufactured from the blank material.

[0002]

2. Description of the Related Art Conventionally, a polycrystalline diamond sintered body (PC) having a very high hardness at a cut portion and excellent abrasion resistance has been used in order to meet the demands for improving cutting performance and extending tool life.
D) or those using a sintered body of cubic boron nitride sintered body (CBN) have been developed. As this type of cutting tool, for example, as shown in FIGS. 12 and 13, a cutting blade 80 is formed from a sintered body formed in a thin chip shape, and the cutting blade 80 is attached to the outer periphery of the base material 8. There is a brazed portion 81 at the corner portion, but in this case, since the cutting blade body 80 has a small bonding area to the base material 8, shortage of adhesive force due to brazing or heat generated by cutting causes a short period of time. As a result, the problem that the cutting blade body 80 comes off from the base material 8 has occurred.

As a cutting tool which has solved the above-mentioned problems, there are a cutting tool using a blank material as shown in FIG. 15 and a blank material as shown in FIG. The former is shown in FIG.
As shown in FIG. 14, an ultra-high pressure sintered body 83 is sintered and fixed only at the front end portion of a base material 82 of a cemented carbide, and as shown in FIG. Things. However, in this tool, since the cutting portion made of the ultrahigh-pressure sintered body 83 is provided only at the tip, the above problem can be solved, but the cutting performance is not particularly excellent.

[0004] As shown in FIG. 16, an ultra-high pressure sintered body 83 is formed in a torsion groove formed in a cemented carbide base material 82 as shown in FIG. 16.
Are filled and buried, and both are integrally sintered and fixed, and a torsion blade is formed on the ultrahigh-pressure sintered body 83 in a drill manufacturing process. However,
When this blank material is used for a drill, it is necessary to cut off the tip having the ultrahigh-pressure sintered body 83 into a drill tip shape, so that it is very difficult to process and furthermore, both ends are supported. It is difficult to manufacture a high-precision drill because machining cannot be performed in this state.

[0005] In order to facilitate the machining of the tip portion, it is conceivable that the latter torsion groove of the blank material is stopped halfway from one end to the other end. As will be understood from the above, the machining is not easy. That is, the processing of the twist groove is performed using a disk-shaped whetstone having a certain diameter (for example, 150 mm in diameter). (The groove becomes shallower toward the end), and as a result, the end of the ultrahigh-pressure sintered body 83 on the tip end side becomes thinner. Therefore, since the thin ultra-high pressure sintered body 83 cannot form a twisted blade, it is used to form the tip of the drill, and it is difficult to machine the tip. turn into.

[0006]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a blank for manufacturing a drill which can easily and inexpensively manufacture a drill having high precision and excellent wear resistance. Is inexpensive and has excellent wear resistance
It is an object of the present invention to provide a high-performance drill manufacturing method .

[0007]

[Means for solving the problem]. In the blank material for manufacturing a drill according to the present invention, an ultra-high pressure sintered body made of polycrystalline diamond or cubic boron nitride is filled and buried in a twist groove formed on an outer peripheral surface of a cylindrical base material sintered body. And a first blank material in which the ultrahigh-pressure sintered body and the base material sintered body are sintered and fixed, and a base material sintered body having one end surface having substantially the same shape as the end surface of the first blank material. Wherein the end faces of the first blank material and the second blank material are fixed by sintering at an ultra-high pressure and a high temperature, and the second blank material is a drill tip. And the first blank material is a part for manufacturing a twist blade following the ultrahigh-pressure sintered body. . Method for producing a drill of the present invention is to secure the shank material blank for the drill production according to claim 1, the
2 After processing and forming the center part on the blank material,
A twisted blade is formed on the ultra-high pressure sintered body of the blank material, and a tip is formed on the second blank material side .

[0008]. In addition, the second blank material described in
It is desirable to form it into a short columnar shape.

[0009]

The present invention operates as follows. Blank material
Of these, expensive materials are polycrystalline diamonds that make up ultra-high pressure sintered compacts.
Mond or cubic boron nitride.
Compared to the latter one described above, the part
The amount to be deleted by the work is reduced. Because this is
For blank materials, use expensive materials except for necessary parts.
Because they are not. Therefore, the blank material itself
Cost reduction can be achieved with construction. In addition, blank material
Particularly hard materials are polycrystalline diamond or cubic nitride.
It is an ultra-high pressure sintered body composed of boron.
The drill tip is manufactured from the material, and the second blank material is
The torsion blade is to be manufactured following the high pressure sintered body
From the comparison with the latter described in the section of the prior art
As a result, machining of the hard part at the tip of the drill is eliminated,
Processing becomes easy as a whole. Therefore, this blanc
Manufacturing drills using drilling material reduces cost
It is. Also, when a drill is manufactured using the blank material of the present invention, the torsion blade is made of polycrystalline diamond or cubic crystal.
It is composed of an ultra-high pressure sintered body made of boron nitride.
Since it is sintered and fixed at an extremely high temperature, the twisting blade does not come off due to cutting heat, and the twisting blade is less likely to be worn. That is, the tool has a very long life.

[0010] In particular, when the outer peripheral corner portion, which is the most important in drill performance, is formed of an ultra-high pressure sintered body, the tool life becomes longer. On the other hand, when the above-described drill is formed from the blank material for manufacturing a drill of the present invention,
Since the first blank material is made of a cemented carbide, it is easy to form a center portion for mounting the machine on the first blank material. This has the effect that a simple drill can be manufactured economically.

In the case where a blank material for drill production is used in which the second blank material is sintered and fixed to both ends of the first blank material, the shank material is fixed to the two divided portions. Thus, two high-performance drills can be manufactured from one blank.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. As shown in FIG. 1, the drill of this embodiment includes a blade portion H and a shank portion S joined to one end of the blade portion H. The blade portion H has a configuration in which two twisted grooves 15 and two lands 14 are alternately arranged as shown in FIGS. 1 and 2, and one end edge of each land 14 as shown in FIG. 1. And a helical twisting blade 10 formed at the end of the helical blade, and a linear tip portion 20 continuous with the tip of the twisting blade 10. The base material of the blade portion H is made of a cemented carbide, and the tip side portion (a certain range) of the torsion blade 10 is higher in hardness and wear resistance than the cemented carbide. It is constituted by a wear-resistant sintered body (in this specification, referred to as an ultra-high pressure sintered body 12). In addition, as the ultrahigh-pressure sintered body 12, if the sintered body has a higher hardness than a cemented carbide and is excellent in wear resistance,
Any known ones can be used, especially PCD and CNB.
It is desirable to employ a powder obtained by sintering the powder of the above under high temperature and ultra high pressure.

The shank portion S is made of a cemented carbide and is set in a columnar shape having substantially the same diameter as the blade portion A as shown in FIG. In this embodiment, the shank S
Is made of a cemented carbide, but may be a material having a certain rigidity, for example, steel. Although the drill of this embodiment is configured as described above, the blank material B constituting the tip portion (having a certain range) of the blade portion H is composed of the first blank material 1 and the second blank material 2. ing. Here, a method for manufacturing the blank material B will be described with reference to the drawings. First Step First, two twisted grooves 11 are formed on the outer peripheral surface of the cemented carbide base material sintered body to form a blank material 1 'as shown in FIG. Note that the twist groove 11 is set corresponding to the location where the twist blade 10 shown in FIG. 1 is formed.

The second blank material 2 includes the first blank material.
It is formed in a cylindrical shape having the same diameter as the blank material 1 and slightly longer than the tip of the drill. Second Step Next, the blank material 1 'and the second blank material 2 shown in FIG.
4 (cobalt powder is interposed in the mutual pipe) as shown in FIG. 4, and the twisted groove 11 of the blank material 1 'is filled with a raw material powder to be an ultra-high pressure sintered body 12 mixed with a suitable sintering aid. Then, the whole shape is made to be a substantially perfect columnar shape. After the third step , the capsule (container) K produced in the second step
And into a heating / pressurizing device 9 shown in FIG. 5, where the pressure is about 45,000 atmospheres or more, and the temperature is about 1,300 to 1,600.
Hold for 3 minutes or more under the condition of ° C. Then, blank material 1 '
And the second blank material 2 are sintered and fixed to each other, and the raw material powder filled in the twist groove 11 of the blank material 1 ′ is sintered to form an ultra-high pressure sintered body 12 in the twist groove 11. . That is, the blank material 1 ', the front-end-side blank material 2, and the ultrahigh-pressure sintered body 12 are fixed by sintering, and the blank material B as shown in FIG. 6 is completed.

The heating / pressing device 9 shown in FIG.
It has a structure that can be pressurized from three axes of Y and Z (can be pressurized from six directions), and can produce a three-dimensionally shaped sintered body. Next, a method of manufacturing a drill using the blank material B manufactured in the first to third steps will be described. First Step First, the tip side blank material 2 in the blank material B manufactured as described above is ground by a diamond grindstone until it reaches the end of the ultrahigh-pressure sintered body 12, and has a convex shape as shown in FIG. Is formed. Then, a shank material S 'is brazed to the other end of this to produce a semi-finished product P of a drill as shown in FIG. In this embodiment, the center portion 19 has a convex shape. However, the center portion 19 may have a shape as required. Second Step Next, as shown in FIGS. 1 and 2, a twist groove 15 and a twist blade 10 are formed on the outer peripheral surface of the first blank material 1 in the semi-finished product P of the drill.

First, the semi-finished product P is mounted on a tool grinder or the like, and two pieces of ultrahigh-pressure sintered body 12 are left on the outer peripheral surface of the blank material B by a diamond grindstone so that a margin for finishing remains. The torsion groove 15 and the land 14 are ground. Third step and twisted groove 15 and land 1 processed in the second step
4 is subjected to precision and high-precision finishing of the ultrahigh-pressure sintered body 12 by electric discharge machining, electrolytic polishing, or the like to form the torsion blade 10 and the tip end portion 20.
Will be completed. In this embodiment, machining is performed so that the connecting portion between the torsion blade 10 and the tip portion 20 becomes the end portion of the ultrahigh-pressure sintered body.

Since the drill of this embodiment is constructed as described above, it has excellent wear resistance and high performance as described in the column of operation and effect. On the other hand, in the drill of the above embodiment, a blank material Ba shown in FIG. 9 can be employed instead of the blank material B for manufacturing the drill. As shown in the drawing, the blank material Ba has the first blank material 1a set to be twice as long as the first blank material of the above embodiment, and the first blank material 1a
The second blank material 2 is sintered and fixed at an ultra-high pressure and a high temperature on both end surfaces, respectively. If the first to third steps for manufacturing the blank in the above embodiment are performed in substantially the same manner, FIG. →
It can be manufactured in the order of FIG. 11 → FIG.

When the drill of the above embodiment (see FIGS. 1 and 2) is manufactured from the blank material Ba, the drill is divided at a position indicated by a two-dot chain line shown in FIG. The first to third steps may be performed to manufacture the drills described above, and in this case, two high-performance drills can be manufactured from one blank material.

[0019]

As described above, the present invention has the following advantages. From the contents described in the column of action,
It is possible to provide a blank material for manufacturing a drill, which can easily and inexpensively produce a drill having high precision and excellent wear resistance,
Furthermore, high performance drills that are inexpensive and have excellent wear resistance
The manufacturing method could be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a drill according to an embodiment of the present invention.

FIG. 2 is a detailed view of a cutting edge of the drill.

FIG. 3 is a view showing a base material of a first blank material and a second blank material.

FIG. 4 is a view showing a state in which a first blank material and a second blank material are brought into contact with each other.

FIG. 5 is a conceptual explanatory view of a heating / pressing device used for manufacturing the drill.

FIG. 6 is a view showing a blank material for manufacturing the drill according to the embodiment of the present invention.

FIG. 7 is a view showing a state in which a center portion for machining is formed by machining the blank material.

FIG. 8 is a view showing a state where a shank material is fixed to the machined blank material shown in FIG. 7;

FIG. 9 is a diagram showing a blank having another configuration for manufacturing the drill according to the embodiment of the present invention.

FIG. 10 shows a first blank material in the blank material,
The figure which showed the base material of the 2nd blank material.

FIG. 11 is a diagram showing a state in which a first blank material and a second blank material are brought into contact with each other in the blank material.

FIG. 12 is a side view of the drill shown in the section of the prior art.

FIG. 13 is a detailed view of a cutting edge of the drill shown in FIG. 12;

FIG. 14 is an explanatory view of a main part of a drill shown in the section of the prior art.

FIG. 15 is a view showing a blank material for a tip portion of the drill shown in FIG. 14;

FIG. 16 is a diagram showing a shank fixed to a blank material for an end mill shown in the section of the prior art.

[Explanation of symbols]

 B Blank material Ba Blank material 1 First blank material 2 Second blank material 10 Twisted blade 11 Twisted groove 12 Ultra-high pressure sintered body 20 Tip

Claims (4)

(57) [Claims] An ultra-high pressure sintered body made of polycrystalline diamond or cubic boron nitride is filled and buried in a twist groove formed on the outer peripheral surface of a cylindrical base material sintered body, and said ultra high pressure sintering is performed. Blank material in which a body and a base material sintered body are sintered and fixed, and a second blank material in which one end surface is formed of a base material sintered body having substantially the same shape as the end surface of the first blank material Wherein the end faces of the first blank material and the second blank material are fixed by sintering at an ultra-high pressure and a high temperature, and the second blank material is a part for manufacturing a drill tip. Wherein the first blank is a part for manufacturing a twisted blade in accordance with the ultra-high pressure sintered body, wherein the blank is used for manufacturing a drill. 2. The blank according to claim 1, wherein the second blank is formed in a short columnar shape. 3. The blank according to claim 1, wherein the base material sintered body is a cemented carbide. 4. A shank material is fixed to the blank material for manufacturing a drill according to claim 1, and a center portion is fixed to the second blank material.
After forming a twist, a torsion blade is formed on the ultra-high pressure sintered body of the first blank material, and a tip portion is formed on the second blank material side.
Forming a drill.