JP2742784B2 - Blanks and drills for drill production - 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 for manufacturing a drill having a torsion blade (blank for manufacturing a drill) and a drill manufactured from the blank.

[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.

[0003] As this kind of cutting tool, for example, FIG.
As shown in FIGS. 2 and 13, there is a cutting blade body 80 formed from a sintered body formed into a thin chip shape, and the cutting blade body 80 is brazed 81 to the outer peripheral corner of the base material 8. However, in this case, the cutting blade body 80 is detached from the base material 8 in a short period of time due to the shortage of the adhesive force due to brazing and the heat generated by the cutting because the cutting area of the cutting blade body 80 is small. Had a problem that

[0004] As a cutting tool which has solved the above problem, there is a cutting tool using a blank material as shown in FIG. 15 and a blank material as shown in FIG.

In the former, as shown in FIG. 15, an ultra-high-pressure sintered body 83 is fixed by sintering only at the tip end of a cemented carbide base material 82, and as shown in FIG. Body 83
A tip portion 84 is formed at the portion. However,
In this tool, since the blade portion made of the ultrahigh-pressure sintered body 83 has only the tip, the above problem can be solved, but the cutting performance is not particularly excellent.

[0006] 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 is used for a drill, it is necessary to cut off the tip having the ultrahigh-pressure sintered body 83 into the shape of a drill tip, which makes processing very difficult. Since it is impossible to perform machining with both ends supported, it has been difficult to manufacture a high-precision drill.

In order to facilitate the machining of the tip, 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.

[0009]

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. It is an object of the present invention to provide a high-performance drill which is inexpensive and has excellent wear resistance.

[0010]

[Means for Solving the Problems] 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. 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. And a second blank material is sintered and fixed at both ends of the first blank material at an ultra-high pressure and a high temperature. . The drill according to the present invention is a drill formed by fixing a shank material to a half of a blank material for manufacturing a drill described in the above, and forming a torsion blade and a tip portion continuous with the shank material in the blank material portion. In addition, a twisted blade is formed on the ultra-high pressure sintered body of the first blank material in the blank material, and a tip is formed on the second blank material side. . It is preferable that the second blank material described in (1) is formed in a short columnar shape.

[0011]

The present invention operates as follows.

If the shank material is fixed to the blank material divided into two parts, two high-performance drills can be manufactured from one blank material.

The expensive material of the blank material is polycrystalline diamond or cubic boron nitride constituting the ultra-high-pressure sintered body, but the portion is more expensive than the latter material described in the section of the prior art. Is reduced by processing such as polishing. This is because this blank does not use expensive materials except for the necessary parts.
Therefore, it is possible to reduce the cost of manufacturing the blank material itself.

A particularly hard material among the blank materials is an ultra-high pressure sintered body composed of polycrystalline diamond or cubic boron nitride. The drill tip is manufactured from the second blank member, and the first blank material is manufactured. Since the torsion blade is manufactured in accordance with the ultra-high pressure sintered body, compared to the latter one described in the section of the prior art, the processing of the hard portion at the tip of the drill is eliminated, and the processing is performed as a whole. Becomes easier. Therefore, if a drill is manufactured using this blank material, the cost can be reduced.

Further, when a drill is manufactured by using the blank material of the present invention, the torsion blade is formed of an ultra-high pressure sintered body made of polycrystalline diamond or cubic boron nitride.
The super-high pressure sintered body that constitutes the torsion blade is sintered and fixed to the base metal sintered body at an ultra-high pressure and an ultra-high temperature, so that the torsion blade does not come off due to cutting heat, and the torsion blade is hard to wear. It will be. That is, the tool has a long life.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the drill according to this embodiment includes a blade portion H and a shank portion S joined to one end of the blade portion H.

As shown in FIGS. 1 and 2, the blade H has a structure in which two twisted grooves 15 and two lands 14 are alternately arranged. As shown in FIG. Has a spiral torsion blade 10 formed at one end edge of the torsion blade, and a linear tip portion 20 continuous with the tip of the torsion 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). As the ultra-high pressure sintered body 12, any known sintered body can be used as long as it is a sintered body having higher hardness and higher wear resistance than a cemented carbide. In particular, powder of PCD or CNB can be used. It is desirable to employ one sintered at 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 portion S is made of a cemented carbide, but may be made of a material having a certain rigidity, for example, steel.

Although this drill is constructed as described above, the blank material B constituting the tip portion (having a certain range) of the blade portion H is composed of a first blank material 1 and a 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.

Note that the second blank 2 is made of the first 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 grooves 11 of the blank material 1 ′ is sintered to form an ultrahigh-pressure sintered body 12 in the twist grooves 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 connection portion between the twist blade 10 and the tip portion 20 becomes the end portion of the ultrahigh-pressure sintered body.

Since the drill is constructed as described above, it has excellent wear resistance and high performance as described in the section 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 in place of the blank material B for manufacturing a drill.

The blank material Ba is, as shown in FIG.
The first blank material 1a is set to be twice as long as the first blank material of the above-described embodiment, and the second blank material 2 is applied to both end surfaces of the first blank material 1a at an ultra-high pressure / high temperature. If the first to third steps for manufacturing the blank of the above embodiment are performed in substantially the same manner, the blank can be manufactured in the order of FIG. 10 → FIG. 11 → FIG.

When manufacturing the drill of the above embodiment (see FIGS. 1 and 2) from the blank material Ba,
This is divided at the position of the two-dot chain line shown in FIG.
What is necessary is just to perform the 1st-3rd process for manufacturing the drill of the said embodiment, and in this case, two high performance drills can be manufactured from one blank material.

[0029]

Since the present invention has the above-described configuration, it has the following effects.

From the contents described in the column of operation, if the shank material is fixed to the blank material divided into two, two high-performance drills can be manufactured from one blank material. A high-performance drill that is inexpensive and has excellent wear resistance can 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 view 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 torsion groove formed on an outer peripheral surface of a columnar base material sintered body. A first blank material in which the sintered body and the base material sintered body are fixed by sintering, and two base material bodies each having one end face formed of a base material sintered body having substantially the same shape as the end face of the first blank material. A blank material for drill production, comprising: a second blank material, wherein the second blank material is sintered and fixed at both ends of the first blank material at an ultra-high pressure and a high temperature. 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 a blank obtained by dividing the blank material for manufacturing a drill according to any one of claims 1, 2 and 3, and a torsion blade and a front end portion continuous with the shank material are attached to the blank material portion. Wherein the twisted blade is formed on the ultra-high pressure sintered body of the first blank material in the blank material, and a tip portion is formed on the second blank material side. Drill to do.