JPH05117718A - Method and device for extruding rod-shaped member having spiral hole - Google Patents

Abstract

PURPOSE:To eliminate the need for cutting a groove and a web at the time of forming a rod-shaped member having a spiral hole and to improve productivity and yield of the material by using this extruder. CONSTITUTION:A cylindrical nozzle 4 connected to the tip 2b of a cylinder 2, a spirally twisted pin 10 set at the axial center of the nozzle 4, a screw 5 (pressing means) for extruding the molding material packed in the cylinder 2 from the nozzle 4 and a means 11 for rotating the guide pin 10 are provided to constitute an extruder 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion molding method and apparatus for molding a rod-shaped member having a single or a plurality of spiral holes in a shaft core, for example, an intermediate product of cemented dolly, and particularly, by reducing the number of manufacturing steps. The present invention relates to an extrusion molding method and apparatus capable of improving productivity and improving material yield.

[0002]

2. Description of the Related Art For example, in a cemented carbide drill,
For the purpose of improving lubricity and cooling during cutting, there is a drill body in which a spiral hole is formed in the shaft core and lubricating oil is supplied to the cutting portion from the spiral hole. In the case of manufacturing such a cemented carbide drill, a cemented carbide powder and an organic binder are kneaded to form a clay-like molding material, which is extruded into a rod-shaped member as an intermediate product by an extrusion molding device. At the same time, a spiral hole is formed in the shaft center of the rod-shaped member during this extrusion. After that, a method is employed in which the rod-shaped member is degreased and temporarily fired, and the outer peripheral surface of the rod-shaped member is cut to form a drill blade, and then the rod is fired to form a drill. As an extrusion molding device for forming a spiral hole in such a rod-shaped member, there has been conventionally known, for example, Japanese Patent Application Laid-Open No. 62-107908, Japanese Patent Application Laid-Open No.
There is a structure described in Japanese Patent No. 156405. This forming apparatus mainly forms a twist groove or a twist ridge extending in the axial direction on the inner peripheral surface of the nozzle, and disposes the guide pin on the axis of the nozzle, and It has a structure in which the upper end is fixed to a support member. To mold a rod-shaped member with this extrusion molding device, a molding material is pushed into the nozzle. Then, the molding material is pushed out from the extraction port of the nozzle so as to wrap around the guide pin while rotating along the twist groove in the nozzle. As a result, a rod-shaped member having a spiral hole in its axis is formed.

[0003]

By the way, in the extrusion molding apparatus described in each of the above-mentioned prior art publications, since the extrusion material is structured to be extruded while being rotated by the twist groove or the convex portion of the nozzle, A spiral groove or web is formed on the outer peripheral surface. Therefore, in order to form a drill, the groove and the web are once scraped off by cutting to form a round bar, and then a drill blade is formed on the round bar. There is a problem that productivity is low as much as necessary. In addition, there is a problem that the yield of the material is poor because the cutting allowance is required to scrape the groove or the web.

The present invention has been made in order to solve the above-mentioned conventional problems, and a rod-shaped member having a spiral hole capable of improving productivity without the need for cutting grooves and webs and improving the yield of materials. It is an object of the present invention to provide an extrusion molding method and apparatus.

[0005]

SUMMARY OF THE INVENTION Therefore, according to the invention of claim 1, in a method of extruding a rod-shaped member having a spiral hole, a cylinder having a guide pin helically twisted and formed at the axis of the nozzle. It is characterized in that the inside of the spiral hole is formed by filling the inside with a molding material, pressurizing the molding material to flow out from the nozzle, and rotating the guide pin. The invention according to claim 2 is characterized in that the cylindrical nozzle connected to the cylinder, the guide pin disposed on the axis of the nozzle and twisted in a spiral shape, and the molding material filled in the cylinder are An extrusion molding apparatus for a rod-shaped member having a spiral hole, comprising: a pressurizing unit that pushes out from a nozzle; and a drive unit that rotates the guide pin.

[0006]

According to the extrusion molding method and apparatus according to the present invention,
Since the pressurizing means for pushing out the molding material in the cylinder from the nozzle and the drive means for rotating the guide pin are provided,
A straight rod-shaped member that does not rotate is extruded from the nozzle, and a spiral hole is formed in the axis of the rod-shaped member by the guide pin that rotates when passing through the nozzle. As a result, it is possible to form a cylindrical rod-shaped member having no groove or web.
For example, the drill blade can be directly formed, the conventional step of scraping the groove or the web can be omitted, and the productivity can be improved accordingly. Further, since it is not necessary to provide a cutting allowance for scraping the groove or the web, the yield of the material can be improved accordingly.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views for explaining an extrusion molding method and apparatus for a rod-shaped member having a spiral hole according to a first embodiment of the present invention. In the figure, reference numeral 1 is an extrusion molding apparatus of the present embodiment, which is configured such that a screw 5 is inserted into a cylindrical cylinder 2 and this is driven and rotated by a drive unit 11. A hopper 3 is connected to a rear portion 2a of the cylinder 2 and a tip portion 2b of the cylinder 2 is tapered. A nozzle 4 is connected to the tip 2b so as to be coaxial with the cylinder 2. The nozzle 4 has a straight cylindrical shape, and the inner diameter of the nozzle 4 is set to be substantially the same as the outer diameter of the drill as a product.

The screw 5 as a pressurizing means extending in the axial direction of the cylinder 2 is inserted into the cylinder 2. The screw 5 is formed by spirally winding a blade 7 around the outer periphery of a shaft 6. There is. The front end 6a of the shaft 6 is located at the tip 2b of the cylinder 2, and the rear end 6b projects outward from the cylinder 2. A portion of the shaft 6 between the rear end portion 6b and the cylinder 2 is rotatably supported by a bearing 8, and a front portion of the shaft 6 is rotatably supported by a bearing 9 arranged in the central portion of the cylinder 2. The screw 5 is rotatably supported. A large number of through holes are formed around the bearing 9, and a molding material described later flows through the holes.

The front end 6a of the shaft 6 has two guide pins 10, 10 coaxially with the shaft 6.
Are connected and fixed, and each of the guide pins 10 is located at the axis of the nozzle 4. Each guide pin 10 is formed in a spiral shape so as to form a predetermined twist angle, and each guide pin 10 is set to have the same length as the axial length of the nozzle 4.

Further, the drive device 11 is connected to the rear end portion 6b of the shaft 6 of the screw 5, and the drive device 11 connects the shaft 6 to a speed reducer 11a and connects the speed reducer 11a to a motor. It is configured by connecting 11b. As a result, the screw and each guide pin 10
Are rotating at the same time.

Next, a method for molding a rod-shaped member having a spiral hole by the extrusion molding apparatus 1 of this embodiment will be described.
First, a cemented carbide powder and an organic binder are kneaded to form a clay-like molding material 12, and the molding material 12 is fed to the hopper 3
Then, the cylinder 2 is supplied and filled, and the screw 5 is rotated. Then, as shown in FIG. 2, the molding material 12 is pressurized while being conveyed to the front end portion 2 b of the cylinder 2, is pushed into the nozzle 4, and is rotated by the guide pin 10.
While being wrapped around, is extruded straight from the nozzle 4 in the form of a round bar. As a result, two spiral holes 13 are formed in the axial direction.
The rod-shaped member 14 having is formed.

The rod-shaped member 14 thus obtained is temporarily fired and degreased, a drill blade is cut on the outer peripheral surface of the rod-shaped member 14, and then fired at a high temperature to manufacture a cemented carbide drill.

As described above, according to this embodiment, the cylinder 2
Since the screw 5 for pushing out the molding material 12 is inserted therein, the guide pin 10 is fixed to the front end 6a of the shaft 6 thereof, and the drive device 11 is connected to the rear end portion 6b,
As described above, the straight rod-shaped member 14 that does not rotate can be pushed out from the nozzle 4, and the spiral hole 1 is formed in the axis of the rod-shaped member 14 by the rotation of the guide pin 10.
3 can be formed. As a result, the rod-shaped member 1
4, the drill blade can be directly cut, and the productivity can be improved as much as the conventional step of scraping the groove or the web can be omitted. Moreover, in this embodiment, the rod-shaped member 14 can be continuously manufactured by supplying the molding material 12 from the hopper 3, and the productivity can be improved also from this point. Also,
In this embodiment, since the inner diameter of the nozzle 4 can be set to be substantially the same as the outer diameter of the drill, it is not necessary to provide the bar-shaped member with a shaving allowance for shaving the groove or the web, and the material yield is improved accordingly. The cost can be reduced.

FIG. 3 is a view for explaining the extrusion molding method and apparatus according to the second embodiment of the present invention. The extrusion molding apparatus 20 of the present embodiment is configured by connecting and forming a cylindrical nozzle 22 that extends in a direction orthogonal to the axis of the cylinder 21 at the lower end portion 21a of the cylinder 21. This nozzle 22
A shaft 23 is rotatably inserted in the axis of
Two guide pins 24, 24 are provided at the tip of the shaft 23.
Is fixed.

In this embodiment, the shaft 23
A drive device 25 including a speed reducer 25a and a motor 25b is connected to the rear end portion of the cylinder 21, and a piston 26 as a pressurizing means is inserted into the cylinder 21 so as to be movable back and forth.

To form a rod-shaped member by the extrusion molding apparatus 20 of this embodiment, the shaft 23 is rotated while the molding material 27 in the cylinder 21 is pressed by the piston 26. Then, the molding material 27 is pushed into the nozzle 22 and is pushed out from the nozzle 22 in a round bar state while wrapping the rotating guide pin 24. As a result, a rod-shaped member 29 having two spiral holes 28 in the axial direction is formed.

Also in the extrusion molding apparatus 20 of this embodiment,
Since the piston 26 as a pressurizing means is inserted into the cylinder 21 and the guide pin 24 is fixed to the shaft 23 inserted into the nozzle 22, the drive device 25 is connected to the shaft 23. Since the straight rod member 29 that does not rotate can be extruded, the drill blade can be directly formed, the productivity can be improved, and the material yield can be improved, and the same effect as that of the above-described embodiment can be obtained.

[0018]

As described above, according to the extrusion molding method and apparatus of the rod-shaped member having the spiral hole according to the present invention, the molding material in the cylinder is extruded from the nozzle and is disposed on the axis of the nozzle. Since the guide pin is rotated, it is possible to eliminate the step of cutting the groove and the web, improve the productivity, and improve the material yield.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an extrusion molding method and apparatus for a rod-shaped member having a spiral hole according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing a method for molding a rod-shaped member by the extrusion molding apparatus of the above embodiment.

FIG. 3 is a sectional view illustrating an extrusion molding apparatus according to a second exemplary embodiment of the present invention.

[Explanation of reference numerals] 1,20 Extrusion molding device 2,21 Cylinder 4,22 Nozzle 10,24 Guide pin 5 Screw (pressurizing means) 11,25 Driving device (driving means) 26 Piston (pressurizing means) 12,27 Molding material 13,28 Spiral hole 14,29 Rod-shaped member

Claims (2)

[Claims] 1. A method for extruding a rod-shaped member having a spiral hole, in which a molding material is filled in a cylinder having a guide pin helically twisted and formed at the nozzle axis, and the molding material is filled with the molding material. An extrusion molding method for a rod-shaped member having a spiral hole, wherein the spiral hole is formed by rotating the guide pin while flowing out from the nozzle by applying pressure. 2. A cylinder filled with a molding material, and a cylinder provided at a tip end of the cylinder, the nozzle being provided with the cylinder.
A spiral hole characterized by comprising a guide pin twisted in a spiral shape, a pressurizing means for pushing out the molding material filled in the cylinder from the nozzle, and a driving means for rotating the guide pin. An extrusion molding apparatus for a rod-shaped member having the same.