JPH026802B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a drill material, and more specifically, the present invention relates to a method for manufacturing a drill material, and more specifically, a spiral cutting edge shape on the outer periphery and the formation of not only a spiral oil hole but also a shank in the land area. This invention relates to a manufacturing method for drill material that can be made extremely easily.

[Prior Art] As is well known, a drill has a spiral blade shape formed at a predetermined angle on its outer peripheral surface, and most of the drills have an oil hole formed in the land portion to supply cutting oil to the tip of the drill. has been done.

In the past, several manufacturing methods were used for this purpose, and in order to form a spiral blade shape on the outer periphery, a cylindrical or rod-shaped ultra-hard material was molded and sintered, and then a diamond tool was used. It was used to create grooves and create blades.

Regarding the oil hole in the land area, one of the problems is that in the case of a drill made of ordinary tool steel, a straight oil hole is first formed before forming a spiral cutting edge shape on the outer periphery. The rear drill material is twisted to form a spiral oil hole. Part 2
In the case of drills made of carbide materials, the
- As seen in No. 226231, an inner core body with a spiral groove formed on its outer periphery is inserted into the outer body, and a spiral oil hole is formed between the groove on the surface of the inner core body and the circumferential surface of the outer body. After that, a spiral blade is formed on the surface of the outer shell using a diamond tool.

According to the above technology, since a diamond tool must be used to form a spiral blade shape, the blade machining becomes a high-precision machining and complicated machining, and there is a limit to the reduction in manufacturing costs.
Further, with regard to spiral oil holes, there are many manufacturing steps, and there is a limit to the reduction in manufacturing costs. Therefore, as seen in Japanese Patent Application Laid-Open No. 61-227101, a spiral groove shape is formed on the circumferential surface from one end to the other end using a powder extrusion molding method using ultra-hard material powder as a raw material. At the same time, a method was proposed in which a spiral hole was formed in the land area from one end to the other, and then this primary molded material was sintered to produce a drill material.

According to this technology, it is easy to form a spiral blade shape on the peripheral surface, and at the same time, it is easy to form a spiral oil hole in the land area, and the overall production is extremely efficient and inexpensive. Can be supplied to the market.
However, looking at the prior art, the method of forming a shank in this drill material is not particularly disclosed in JP-A No. 61-227101, and the method of forming a shank in the drill material has an internal passage as seen in JP-A No. 54-159791. The cylindrical body was prepared separately and was manufactured by connecting the spiral hole in the land portion of the drill material and the internal passageway of the cylindrical body in communication with each other.

[Problems to be Solved by the Invention] According to the above-mentioned prior art, in terms of the manufacturing method of the drill material including the shank part, the shank is attached to the rear end of the spirally formed blade part by brazing, etc. By twisting them together, there is a limit to how much strength can be improved at the joints, and there has been a need for improved durability. Furthermore, in terms of manufacturing, it is difficult to process as it is necessary to perform brazing or the like while the internal holes of the two members are in communication with each other.

[Objective] Therefore, the object of the present invention is to easily form a spiral blade shape, and also to form a part in which a spiral groove shape is formed, that is, a blade part and a cylindrical shank part. It is formed by things,
More specifically, by making the core of the shank integral with the blade part, strength can be improved, providing a drill material with superior durability, and in addition, the shank is integrally connected. To provide a drill material in which it is easier to form a hole in a land part and has excellent productivity.

[Means for solving the problems] [Operation] In order to achieve the above object, the present invention has the following technical means.

That is, to explain using the reference numerals used in the embodiments shown in the accompanying drawings corresponding to the embodiments, the present invention relates to a method for manufacturing a drill made of an ultra-hard material: At the same time, a spiral groove is formed on the circumferential surface from one end to the other using a powder extrusion molding method, and at the same time, a spiral hole is formed in the land portion from one end to the other. In the manufacturing method of drill material, in which the primary molded material is sintered to form a drill material, one side of the drill material is left as is, and a ferrous metal is filled in the groove of the other side, and the other side is formed into a cylindrical shape. This creates a shank.

To explain more specifically, as the ultrahard material powder that can be used in the above, as usual, cemented carbide powder (WC-Co type, WC-Ni type,
WC―TaC―TiC―Co series, WC―TaC―TiC―Ni
etc.), so-called cermet powder (as ceramics, we use powders of metal oxides, carbides, silicides, borides, nitrides, etc., and mix them with powders of cobalt, nickel iron, etc. as metals, Particles sintered in a vacuum or other suitable protective gas) or powders of ceramic-based ultrahard materials such as SiC--Ni and SiN--N can be used. Then, necessary auxiliary agents such as wax are mixed with these raw material powders, and these powders are extruded using a powder extrusion molding machine, that is, extruded under pressure from a mold shaped like a drill bit to be processed, and extruded from one end. A primary material is obtained in which a spiral groove is press-molded continuously on the circumferential surface of the material up to the other end, and a spiral hole is formed in the land portion. In order to form a spiral hole in the land portion, a rod corresponding to the diameter of the hole may be placed in the mold. In the above, it is better to use a slightly larger amount of wax than usual to make it more viscous and easier to mold.

In addition, one hole may be formed in a spiral shape at the center of the land portion, but two spiral holes may be formed in each of the two flanks at the tip of the drill. After this, one side of the drill material is left as is, and the groove on the other side is filled with iron-based metal, and the other side is made into a cylindrical shank. By doing this, the shank portion becomes integral with the blade on one side, and a core is formed within the cylindrical shank, so that the strength is improved. Moreover, since there is no processing such as aligning the hole in the blade with the hole in the cylindrical shank and brazing the two, productivity is improved.

[Embodiments] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a mold is set in which a spiral blade is formed on the outer periphery at the discharge end of the cylinder end of a powder extrusion molding machine, and a spiral hole is formed in the land portion.

Regarding the spiral hole mentioned above, in the mold,
It is sufficient to arrange a rod with an outer diameter corresponding to the diameter of the hole, and in this example, two spiral holes are formed on each of the two flanks at the tip of the drill. , two rods are arranged.

Now, after this, in the hopper of the powder extrusion molding machine,
A molding material made by mixing an ultra-hard material such as ultra-hard alloy powder, cermet powder, or ceramic powder with an auxiliary agent such as wax is charged and extruded from the mold.
When extruded, these powder materials are twisted in a spiral shape at the mold and extruded, forming a spiral groove A on the outer periphery and forming spiral holes B and C in the land portion. . As a result, a primary molding material 1 is obtained as shown in FIG.

As shown in FIG. 2, this is sintered at the sintering temperature of the powder material to obtain a sintered material 2. Subsequently, it is cut into unit lengths (L) that match the total length of the drill to be machined to obtain unit sintered bodies 3 as shown in FIG.

Each unit sintered body 3 has a spiral groove A formed on its outer periphery, and spiral holes B and C formed in the land portion. A drill material is thus obtained. From now on, as shown in Figure 4,
The groove A on one side is left as is, and the iron-based metal D is filled in the groove on the other side to form a necessary shank 4. This yields a drill material. Then, the drill is completed by searching and polishing the groove A portion and performing secondary processing on the flanks 5 and 6 at the tip or the chip discharge groove 7. As a method for filling the iron-based metal D, a conventionally well-known metallurgical method is used. For example, the grooves are filled with iron-based metal powder and sintered at a sintering temperature, or the molten metal is poured into the grooves and solidified. Moreover, since it is only necessary to fill the groove A, the adjacent blades that partition the groove A may also be covered, or only the groove A may be simply filled.

[Effects of the Invention] As detailed above, according to the present invention, a spiral groove is formed on the circumferential surface from one end to the other end by the powder extrusion method, and at the same time, a spiral groove shape is formed on the circumferential surface from one end to the other end. Since a spiral hole is formed in the land portion of the drill, and this primary material is then sintered to form the drill material, it goes without saying that the spiral-shaped blade on the outer periphery can be manufactured very easily and efficiently. The part where the spiral groove is formed, that is, the blade part on one side and the cylindrical shank part on the other side, are made of one piece, and because there are no connecting parts, the strength is extremely high. Moreover, since the part before being filled with iron-based metal acts like a core, the strength of the shank can be improved and its durability can be increased. In addition, in a drill material where the shank is integrally connected, it is easier to form holes for oil in the land area, and there is no need to align the holes of the two members. In other words, it is easy to form holes, and productivity is improved.

[Brief explanation of drawings]

The attached drawings show examples of the present invention, and Fig. 1 shows the drill material after molding, Fig. 2 shows the drill material after sintering, and Fig. 3 shows the drill material after cutting into unit lengths. Figure 4 shows the completed drill material, where A is the groove and B and C are the oil holes.

Claims (1)

[Scope of Claims] 1. A spiral groove is formed on the circumferential surface from one end to the other end by powder extrusion molding using ultra-hard material powder and necessary auxiliary agents as raw materials, and at this time, one end is simultaneously formed. In the method for manufacturing a drill material, a spiral hole is formed in the land area from one end to the other end, and then this primary molded material is sintered to form a drill material; one side of this drill material is left intact and the other side is sintered. A manufacturing method for drill material characterized by filling the groove of one part with ferrous metal and forming a cylindrical shank on the other side.