JPH093509A - Round rod having spiral oil hole - Google Patents

Abstract

PURPOSE: To provide a round rod having spiral oil hole, in which characteristics at the center part and the outer peripheral part are different, and a production thereof. CONSTITUTION: In a pipe-shaped formed body and/or sintered body 3 composed of, a round rod formed body or a sintered body 1 constituting the center part and concentrically arranged one or more layers on the outer layer thereof, a combined body having spiral grooves 4 in either inner layer or plural outer diameters and/or inner diameters and formed such that the inner diameter of the outside pipe is a little smaller than the outer diameter of the adjacent inside pipe in the sintered body is sintered. Then, the round rod having the spiral oil hole of the structure integrally complexed by fastening and/or diffusion joining during sintering in interface contact, is obtd. By this constitution, the round rod having the spiral oil hole used of the material suitable to each drill having different damaged forms in the outer and the inner diameters can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a round bar composite sintered body having a spiral oil hole used for a drill and the like and a method for producing the same.

[0002]

2. Description of the Related Art Many proposals have been made for a method of manufacturing a round bar having a spiral oil hole. For example, in Japanese Patent Publication No. 4-71642, a straight groove is formed in the outer diameter of a hard metal round bar having a plurality of straight thin holes, and this material has a twist angle when hot (1100 to 1300 ° C.). A method of deforming under pressure with a die is disclosed. This method is excellent in that it can be reliably produced, but is not suitable for mass production because heating and cooling must be performed one by one. Also, there is a disadvantage that the die is severely worn due to heating to a high temperature.

In Japanese Patent Publication No. 6-63003, an extruding device and a torsional rotating device are combined to extrude a rod-shaped molded product having a straight hole, and then appropriately rotate the rod-shaped molded product in accordance with the extrusion speed of the molded product to match the twist angle. There is disclosed an extrusion molding machine which obtains a rod-shaped molded body having a helical oil hole by rotating the molded body with a formed torsion roller.

In Japanese Patent Publication No. Hei 6-73764, a spirally deformed helical groove is formed by elastically following a torsion motion caused by a spirally arranged groove in a nozzle inner chamber and a spiral groove in the nozzle inner chamber during extrusion molding. An extrusion method comprising a retained pin is disclosed.

[0005] Any of the above-mentioned methods is an excellent method for producing a round bar having a helical oil hole. For example, when used in a drill or the like, the cutting speed of the central portion and the outer peripheral portion is different. If a material is selected according to the wear resistance, a defect occurs at the center portion where the cutting speed is low, and if a material is selected according to the fracture resistance at the center, there is a problem that the outer peripheral portion wears quickly.

As a method for producing a material different from the central portion and the outer peripheral portion, Japanese Patent Publication No. 61-33645, Japanese Patent Publication No. 61-57123,
It is disclosed in JP-A-6-200302 and the like. Moreover, the present applicant has also applied for a patent application in Japanese Patent Application No. 6-286071. Since none of these has a spiral oil hole, when used for a drill or the like, problems remain in sufficient cooling of the cutting edge during cutting and smooth discharge of chips.

[0007]

The applicant of the present invention has an oil hole which has a sufficient effect of cooling the cutting edge during cutting and a good chip discharging effect, and has a long drill life with a large difference in cutting speed between the central portion and the outer peripheral portion. The inventors of the present invention have earnestly studied the problem of how to make the length longer, and have reached the present invention.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a drill or the like having different damage modes due to a difference in cutting speed between a central portion and an outer peripheral portion thereof. The present invention provides a round bar having an oil hole that is effective in cooling the cutting edge and discharging chips effectively. Specifically, in a combination of a round bar molded body or a sintered body and one or more coaxially arranged pipe-shaped molded bodies or / and a sintered body in the outer layer, either one of the inner layers Has a plurality of spiral grooves in the outer diameter and / or inner diameter, and the dimension of the sintered body of each layer is slightly smaller than the outer diameter of the innermost layer sintered body, and the inner diameter of the outer pipe adjacent to it is slightly smaller. It is characterized by a round bar having a spiral oil hole having an integral structure, which is controlled to the inner diameter of the outermost layer with the dimension of, and its manufacturing method.

[0009]

According to the present invention, the round bar formed body or the sintered body and the outer layer are
In a combination of layers or two or more coaxially arranged pipe-shaped molded bodies or / and sintered bodies, any one of the inner layers or a plurality of outer diameters / and / or inner diameters has a spiral groove, and The outer diameter of the outer pipe adjacent to the outer diameter of the innermost layer sintered body is slightly smaller than the outer diameter of the innermost layer sintered body. Regarding the round bar having a hole and its manufacturing method, each condition will be described in detail below.

The outer layer and / or the inner layer having the spiral groove on the inner diameter can be formed by extrusion molding by powder metallurgy or by molding of a molded body or / and a sintered body or a sintered body. Good. The pipe-shaped molded body and / or the sintered body may be a molded body obtained by any of extrusion molding by powder metallurgy, press molding, and mechanical processing of the molded body, or may be a sintered body. Good.

The outer diameter of the inner layer adjacent to the inner layer must be slightly smaller than the outer diameter of the sintered body of each inner layer. This is because no contact occurs, a large gap is generated, and sufficient tightening or / and diffusion bonding cannot be performed.
Here, it is stated that the inner diameter of the outside adjacent to the inner layer must be slightly smaller than the outer diameter of the sintered body of each inner layer, but the inner layer shrinks depending on the combination conditions such as fine grain composition and outer layer coarse grain composition. Due to the ratio, the outer diameter of the extruded body or the press formed body of the inner layer sometimes becomes larger than the inner diameter of the adjacent outer layer pipe. At this time, the inner layer molded body can be inserted into the adjacent outer layer pipe by pre-sintering or sintering.

In applications where the inner and outer diameters have different damage patterns,
Materials having different characteristics can be combined according to the damage form. For example, cemented carbides having different properties, cemented carbide and cermet, cemented carbide and ceramics, cermet and ceramics, cemented carbide and powdered high-speed steel (high-speed steel produced by powder metallurgy), and the like can be considered. For the combination of materials having different characteristics, it is preferable that the sintering conditions are similar, but when the sintering temperature of the inner layer is higher, only the inner layer is sintered first and then the sufficient tightening or / and The whole may be sintered at a temperature at which diffusion bonding occurs.

More preferably, HIP treatment is performed to eliminate pores remaining in each tightening or diffusion bonding portion of a round bar having a spiral hole integrally formed by sintering.

Further, a single layer or two layers of TiN, TiC, TiCN and Al ₂ O _{3 which} are usually used for products such as a composite round bar having a spiral oil hole formed by the method of the present invention and a drill are manufactured. Those coated with the above coatings also fall within the scope of the present invention.

[0015]

Example 1 A sintered rod inner diameter of a round bar molded body 1 having two spiral grooves 4 at a 180 ° phase in an outer diameter corresponding to M40 of JIS B4053 having a toughness of a planned outer diameter of a sintered body of 4.2 mm is planned. It is inserted into a pipe-shaped molded body 3 of P20 of JIS B4053, which has a wear resistance (high hardness) of 4.1 mm in size and a planned outer diameter of 7.0 mm in the sintered body, and is HIP-processed after sintering. As a result of examining the cross section of the round bar having a spiral oil hole, the spiral groove remained and no pore was observed at the interface between the two. In addition, the outer diameter of the round bar having a spiral oil hole of a one-piece structure is 90 ° in phase with the oil hole. The spiral groove of the book was cut, but it was not directly connected to the spiral oil hole of the inner diameter.

[0016]

[Example 2] A tough fine particle cemented carbide having an outer diameter of 4.2 mm, a round rod sintered body 1 corresponding to Z30 of JIS B4053, a sintered body having an inner diameter of 4.1 mm, and a sintered body having an outer diameter of 7.7 mm.
A pipe-shaped compact 2 having two spiral grooves 4 having a 180 ° phase in an outer diameter corresponding to M40 of JIS B4053 having a toughness of 0 mm, and a predetermined inner diameter of the sintered body 6.9 mm and a predetermined outer diameter of the sintered body 10. As a result of investigating the cross section of a round bar having a spiral oil hole of integral structure, which is pipe-shaped molded body 3 of TiCN-based cermet having welding resistance of 0 mm, is coaxially combined, and subjected to HIP treatment after sintering. Remained and no pore was observed at the interface between the two. Further, the outer diameter of a round bar having a helical oil hole having an integral structure is set to a value of 4.1 mm in a predetermined torsion angle of a spiral groove of a round bar formed body in a sintered body at a phase of 90 ° with the oil hole. The spiral was cut, but was not directly connected to the spiral oil hole of the inner diameter.

[0017]

According to the present invention, it is possible to manufacture a round bar in which a material suitable for a damaged form is arranged in a diametrical direction and one or a plurality of spiral oil holes are accurately arranged. is there. When the round bar of the present invention is used for drilling with a drill or the like, since there is an oil hole up to the tip of the cutting edge, sufficient cutting of the cutting edge and smooth discharge of chips can be performed, and a high-performance cutting tool can be provided. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an assembling step for explaining a manufacturing method of the present invention.

FIG. 2 is a perspective view showing an assembling step for explaining the manufacturing method of the present invention.

[Explanation of symbols]

1 ... Round bar forming the central part, 2 ... Pipe forming the middle part, 3 ... Pipe forming the outer peripheral part, 4 ...
Spiral groove.

Claims (5)

[Claims] 1. A round bar molded body and one or two layers on the outer layer thereof.
In a combination of pipe-shaped compacts arranged coaxially in more than one layer, any one of the inner layers or a plurality of outer diameters / and / or inner diameters have spiral grooves, each of which has an outer shape when a sintered body is formed. A structure in which a combination body in which the inner diameter dimension of the outer pipe adjacent to this is slightly smaller than the diameter dimension is sintered and integrally combined by tightening or / and diffusion bonding at each interface contact during sintering. Round bar with spiral oil holes and its manufacturing method. 2. A round bar sintered body and one or two layers on the outer layer thereof.
In a combination of pipe-shaped compacts arranged coaxially in more than one layer, the outer diameter of the round bar sintered body and / or one of the inner layers or a plurality of outer diameters and / or spiral grooves is formed in the inner diameter. , Sintering a combination body in which the inner diameter dimension of the outer pipe adjacent to each is slightly smaller than the outer diameter dimension when each becomes a sintered body, and tightening or / at each interface contact during sintering. And a round bar having a spiral oil hole, which is integrally compounded by diffusion bonding, and its manufacturing method. 3. A round bar molded product and one or two layers on its outer layer.
It is a combination of pipe-shaped compacts arranged coaxially in more than one layer, and has a spiral groove in any one of the inner layers or multiple outer diameters and / or inner diameters. In a combination body in which the inner diameter dimension of the outer pipe adjacent thereto is slightly smaller than the diameter dimension, the round bar is sintered, the round rod sintered body and the outer pipe-shaped molded body are sintered, and A spiral oil having a structure in which the composite body and the pipe-shaped molded body outside the composite body are sequentially sintered and then sintered, and during sintering, they are integrally compounded by tightening or / and diffusion bonding at each interface contact. Round bar with holes and its manufacturing method. 4. A round bar having a spiral oil hole according to claim 1, wherein a part or all of each layer is made of a material having different characteristics, and a manufacturing method thereof. 5. A round bar sintered body having a spiral oil hole is provided with HI.
A round bar having a spiral oil hole according to claims 1 to 4, which has been subjected to P treatment to eliminate pores remaining at each interface, and a method for producing the same.