JPS61227101A - Extrusion molding machine - Google Patents

Abstract

PURPOSE:To produce a sintered hard drill formed with spiral holes by forming the inside circumferential surface of a molding port of a cylindrical mold as a spiral surface and providing cores for forming spiral hole to the inside of a material to be molded into the molding port. CONSTITUTION:A raw material is inserted into a material cylinder 5 and is pressed rightward by a piston 6. The material is moved to the rear end of a cylindrical die holder 8 and the cylindrical mold 9 via a sectorial spacing 10c of a core supporting member 10 and is pushed into the molding port 9a. The material is rotated along the spiral surface of the molding port 9a and moves toward the top end of the mold 9 while said material is molded to a drill shape when the piston 6 moves further. The spiral spaces are formed by the cores 11, 12 in the material. The molding is removed and sintered when the material is molded to a prescribed thickness. The sintered hard drill 7 formed with the oil holes 2, 3 is thus produced.

Description

[Detailed description of the invention] [Industrial use! P1 This invention relates to an extrusion molding machine used for molding 11 hard material before sintering, and particularly to an extrusion molding machine that can form spiral holes inside a molded object.

[Prior Art] FIG. 4 is a partial view of a drill used in a drilling machine or the like. Inside this type of drill 1, oil holes 2.3 are generally formed in a spiral shape along the cutting edge, and oil is passed through these oil holes 2.3 during drilling to cool or cool the drill. Wear is prevented.

Now, when such a drill 1 is manufactured from carbon steel or high-speed steel, the above-mentioned spiral oil holes 2 and 3 can be formed very easily.

However, when the drill 1 is made of carbide, the oil hole cannot be formed in a spiral shape. Therefore, oil holes as shown in FIG. 5 are usually formed in drills made of carbide. That is, the oil hole 4 passes through the center of the drill, and one end opens at the base end of the drill, while the other end splits into two parts near the tip of the drill, each opening at the tip of the cutting blade.

Here, this carbide drill is manufactured as shown below. First, a combination of the raw material and the screw material is molded using an extrusion molding machine through a mold whose inner peripheral surface has a spiral surface, and then the above-mentioned oil hole 4 is formed and then sintered.

[Problems to be solved by the invention] By the way, when the cutting blade at the tip of a normal drill wears out,
Needs polishing. However, the above-mentioned carbide drill cannot sharpen all of the oil holes divided into 2F, so the length that can be polished is limited and the service life is short.

In view of the above circumstances, an object of the present invention is to provide an extrusion molding machine that can form a spiral oil hole in a carbide drill.

[Means for Solving the Problems J] In order to achieve the above object, the present invention is characterized in that a core is provided inside a molding opening whose inner peripheral surface is a spiral surface.

[Operation 1] With the above-described configuration, when the material is molded and rotated as it advances through the molding mouth, a space from which the material is removed by the core is formed in a spiral shape.

[Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the configuration of an extrusion molding machine according to an embodiment of the present invention. In the figure, 5 is a material cylinder, and 6 is a piston that moves in the horizontal direction in the figure within this material cylinder 5. At the tip 5a of the material cylinder 5, there is a cylindrical die holder holder 7 whose outer diameter is equal to the outer diameter of the material cylinder 5 and whose inner diameter is slightly smaller than the inner diameter of the material cylinder 5.
is attached to the inner periphery of this die holder holder 7,
A cylindrical die holder 8 is fitted in such a way that it cannot be pulled out in the right direction, and a cylindrical mold 9 is fitted in the inner periphery of the die holder 8 so that it cannot be pulled out in the right direction. In this case, the rear end 8a of the die holder 8 has a taper whose inner diameter becomes narrower toward the tip.

Further, the shape of the molding opening 9a of the mold 9 has the cross-sectional shape of a drill as shown in FIG. 2, and its inner peripheral surface has a spiral surface. A drill is formed by pushing a combination of the material and the screw material (hereinafter simply referred to as the material).

Moreover, 10 is a core support member. This core support member 1
0, the outer diameter is the material cylinder 5 as shown in Figure 3.
The core support member 10 is composed of a frame 10a having the same inner diameter as the inner diameter of the frame 10a, and a cross-shaped transition member 10b fixed within the frame 10a.As a result, the core support member 10 has a fan-shaped l! 111i10c, 10
It has c... Two cores 11.12 are planted at the center of one side of the transition member 10b at an interval of 180° on the circumference centered at the center point 0 of the frame 10a. The diameter of the circumference in this case is equal to O, the distance from the thick part P1 of one cutting blade to the thick part P2 of the other cutting blade of the drill shown in FIG.

Each of the cores 11 and 12 is a wire-like member, and the length thereof is longer than the distance from the tip of the material cylinder 5 to the rear end of the mold 9, as shown in FIG. The cores 11 and 12 are bent at an inclination equal to the inclination of the spiral surface on the inner circumference of the mold 9, and form part of a spiral centered on the center point O. The core support member 10 as described above is unrotatably fitted into the tip 5a of the material cylinder 5 with the cores 11 and 12 facing the mold 9 side. In this case, the frame 10a is the die holder holder 7
Abutting against the rear end of the core 11 , 12 , the tip end of the core 11 , 12 is positioned within the molding opening 9 a of the mold 9 .

Further, in this case, the tips of the cores 11 and 12 are always located in the thick portion P1 or P2 within the molding opening 9a, respectively.

In the above configuration, when the material inserted into the material cylinder 5 is pressed to the right in FIG.
c..., moves to the rear end of the die boulder 8 and the mold 9, and is pushed into the molding opening 9a of the mold 9.

moreover. As the piston 6 continues to move, the material is molded into the shape of a drill and advances into the tip of the mold 9 while rotating along the spiral surface of the molding opening 9a. At this time, inside the material, a space from which the material is removed by the cores 11 and 12 is formed in a spiral shape.

Its position is always the thick part P1, P2 of the cutting edge of the drill. Once the molded object has been molded to an appropriate length, the movement of the piston 6 is stopped and the molded object is removed. Inside this molded object, as shown in FIG. 4, two spiral through holes extending from the tip to the base are formed. Next, this molded object is sintered to form a drill.

The inside of the carbide drill manufactured in this manner has a spiral wave pattern similar to that produced with carbon steel or high-speed steel.

[Effect of the invention 1 As explained above, according to the present invention, since the core is provided in the molding opening whose inner peripheral surface is a spiral surface, it is possible to form a spiral hole inside the object to be molded. This makes it possible to extend the life of a carbide drill with a spiral oil hole, thereby providing the effect of dramatically extending the life of the carbide drill.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of an extrusion molding machine according to an embodiment of the present invention, and FIG. 2 is a mold opening 9a of a mold 9.
The arrow view of FIG. 1 and FIG. 3 show the shape of the core 11.1.
4 is a front view showing the shape of the core support member in which No. 2 is implanted;
5 and 5 are partial views showing a drill and an oil hole formed therein, respectively. 5... Material cylinder, 9... Mold, 9a... Molding mouth, 11.12...
...Nakako. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] An extrusion molding machine comprising a material cylinder and a mold provided at the tip of the material cylinder, and molding a material inserted into the material cylinder into a predetermined cross-sectional shape by extruding it from a molding opening of the mold. An extrusion molding machine, characterized in that the inner periphery of the molding port is a spiral surface, and the inside of the molding port is provided with a core that forms a spiral hole inside the object to be molded.