JP2001137937A - Extrusion method for metal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion method for a metal material, which has excellent temp. controllability not likely lowering an extrusion yield and is capable of uniformly heating a whole cross section of the metal material. SOLUTION: In a rotary wheel type extrusion method in which a metal material 8 is drawn into the passage 4 constituting of a groove part 2 of the outer periphery of a rotary wheel 1 and a shoe block 3 to cover a groove part 2 over a prescribed circular arc length of the rotary wheel 1 by the revolution of the rotary wheel 1, the material 8 is pushed on a protrusion 5 for blocking at the bottom of the passage 4 so as to increase the pressure, a formed body 9 of a prescribed shape is extruded from a die 6 based on the pressure, the metal material 8 is heated by causing an electric current to flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extruding a metal material, and more particularly to a method for extruding a metal material using a rotary wheel type continuous extruder.

[0002]

2. Description of the Related Art As an extruding method of a metal material, an extruding method using an extruder equipped with a rotating wheel is known. FIG.
Shows the extrusion method, 1 is a rotating wheel having a groove 2 on the outer periphery, 3 is a shoe block having a groove 2 covered with a predetermined arc length of the rotating wheel 1, 4 is a groove 2 and a shoe lock. Passage formed by 3, 7
Denotes a die holder having damming projections 5 for damping the metal material 8 drawn into the passage 4 by the rotation of the rotating wheel 1. The protrusion 5 increases the pressure of the metal material 8 by its damping action.

[0003] The metal material 8 whose pressure is increased is molded into a molded body 9 having a predetermined shape by a die 6, extruded, and then cooled. In this extrusion method, it is preferable to raise the temperature of the metal material 8 as high as possible, thereby extruding the metal material 8 in a form in which deformation resistance is suppressed. In particular, when extruding a difficult-to-process metal material such as a molded product having a small cross section, a molded product having an irregular cross section, or an alloy, suppression of this deformation resistance is an important issue.

In this extrusion method in which the metal material 8 itself generates heat, the heat generation is usually limited, so that it is necessary to replenish heat more than others in order to suppress deformation resistance. Become. As a heating means for this purpose, a method of preheating the metal material 8 before being fed into the passage 4 or heating the metal material 8 by embedding a heater in the die holder 7 can be considered.

[0005]

However, according to the conventional method of extruding a metal material, when the method of preheating the metal material is employed, the material temperature in the passage 4 is higher than the material temperature in the die 6. For this reason, the metal material 8 may leak from the gap between the groove 2 of the rotating wheel 1 and the shoe block 3, which may significantly reduce the yield of the extrusion process. On the other hand, when embedding the heater in the die holder,
Only the surface of the metal material 8 rises in temperature due to heating, and it is difficult to uniformly heat the entire cross section of the metal material 8.

Accordingly, an object of the present invention is to extrude a metal material having excellent temperature controllability without lowering the yield of the extrusion process and capable of uniformly heating the entire cross section of the metal material. It is to provide a method.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a groove formed on an outer periphery of a rotating wheel rotating in a predetermined direction and a groove formed over a predetermined arc length of the rotating wheel. A metal material is drawn into the passage defined by the shoe block that covers the groove by rotating the rotating wheel in the predetermined direction, and the drawn metal material is rotated in the predetermined direction of the rotating wheel. And presses against the damming projection formed at the back of the passage to generate an extrusion pressure. The extruding pressure causes the metal material to be extruded from a die arranged at a stage subsequent to the damming projection as a molded body having a predetermined shape. In a method for extruding a metal material, a method for extruding a metal material is provided, wherein an electric current is applied to the metal material extruded from the die to heat the metal material. A.

Means for flowing an electric current to the metal material include a metal material before being drawn into the passage and a molded product extruded from the die, or a metal material and a die holder drawn into the passage.
Alternatively, it is preferable that electrodes are brought into contact with or attached to the rotating wheel and the molded body to be extruded, respectively, and current is supplied from these electrodes. It is possible to use a powdery material as the metal material.
It is preferably between the rotating wheel and the extruded molded body.

[0009]

Next, an embodiment of a method for extruding a metal material according to the present invention will be described. In FIG. 1, reference numeral 1 denotes a rotating wheel, 2 denotes a groove formed on the outer periphery thereof, 3 denotes a shoe block for covering the groove 2 over a predetermined arc length of the rotating wheel 1, and the groove 2 and the shoe block 3 A passage 4 is formed therebetween. Reference numeral 5 denotes a damming projection formed at the back of the passage 4, 6 denotes a dice formed in the back of the damping projection 5 in communication with the passage 4, and 7 denotes a dice holder having these damping protrusions 5 and the die 6. Show.

The metal material 8 is drawn into the passage 4 by the rotation of the rotating wheel 1, and the drawn metal material 8 is
, And is pressed against the damming projection 5. The pressure of the metal material 8 is increased by the pressing against the protrusion 5, and the metal material 8 is extruded from the die 6 as a molded body 9 having a predetermined shape based on the pressure.

Reference numerals 10 and 11 denote roller electrodes which rotate in contact with the metal material 8 drawn into the passage 4 and the molded body 9 extruded from the die 6, respectively. As a result of the above configuration, the metal material 8 drawn into the passage 4
Is heated by energization before reaching the die 6, so that the metal material 8 is extruded from the die 6 under a uniform cross-section heating state unique to energization heating.

The feature of this example is that the metal material 8
It is a transition of the electric resistance of the above. The electric resistance is maximum near the die 6 where the metal material 8 is greatly deformed,
Therefore, the temperature of the metal material 8 is highest near the die 6.

As a result, the metal material 8 is extruded from the die 6 with low deformation resistance, and a molded body 9 having a stable size and shape is obtained. When extruding a molded body having a small cross section, a molded body having a modified cross section, or a hard-to-work alloy, the extrusion method according to the present embodiment facilitates this.

Further, since the heating of the metal material 8 is carried out by energization, the heating temperature can be easily controlled by adjusting the current value. That is, it is possible to prevent the material temperature from becoming higher than the temperature at the point S and causing the material to leak from the gap between the shoe block 3 and the passage 4.

FIG. 2 shows another embodiment of the method for extruding a metal material according to the present invention. The difference from FIG. 1 is that a powdery material is used as the metal material 8, and the roller electrode 10 on one side is brought into contact with the rotating wheel 1. Other parts are the same as those in the embodiment of FIG.

Since the powdered metal material 8 is heated by energization and rises in a short time and is melt-sintered under a high pressure, the compact 9 having a dense structure is extruded. become. In this embodiment, it is needless to say that the same effect as in the embodiment of FIG. 1 can be obtained.

[0017]

As described above, according to the method for extruding a metal material according to the present invention, since the metal material is heated by passing an electric current, the metal material can be uniformly heated in a cross section and the heating temperature can be controlled. Therefore, it is possible to reliably prevent the leakage of the material from the gap between the groove of the rotating wheel and the shoe block, which has been a problem in the extrusion method using the conventional preheating. As a result, it is possible to perform a stable extrusion operation with a high processing yield and a suppressed deformation resistance, and to easily extrude a molded product having a small cross section, a molded product having a irregular cross section, or an alloy having difficulty in processing. Will be able to do it.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a method for extruding a metal material according to the present invention.

FIG. 2 is an explanatory view showing another embodiment of the method for extruding a metal material according to the present invention.

FIG. 3 is an explanatory view showing a conventional method for extruding a metal material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating wheel 2 Groove part 3 Shoe block 4 Passage 5 Protrusion for dam 6 Dice 7 Dice holder 8 Metal material 9 Molded object 10, 11 Roller electrode 12 Power supply

Claims (5)

[Claims] 1. A rotating mechanism comprising: a groove formed on an outer periphery of a rotating wheel rotating in a predetermined direction; and a shoe block covering the groove over a predetermined arc length of the rotating wheel. The metal material is drawn by the rotation of the wheel in the predetermined direction, and the drawn metal material is pressed against a damming projection formed in the back of the passage by the rotation of the rotating wheel in the predetermined direction, and the pushing pressure is increased. In the method of extruding the metal material from the die arranged at the subsequent stage of the damming projection by the extrusion pressure, the metal material is extruded from the die as a molded body of a predetermined shape by applying a current to the metal material extruded from the die. A method for extruding a metal material, wherein the metal material is heated by flowing. 2. The method for extruding a metal material according to claim 1, wherein said metal material is drawn by pulling a metal material having one shape selected from a linear body and a powder. 3. The heating of the metal material is carried out by applying a voltage to the metal material drawn into the passage and to an electrode which comes into contact with the molded body of the predetermined shape extruded from the die. The method for extruding a metal material according to claim 1. 4. The method according to claim 1, wherein the heating of the metal material is performed by applying a voltage to the metal material drawn into the passage and to an electrode in contact with a die holder holding the die. Extrusion method of metal material. 5. The method according to claim 1, wherein the heating of the metal material is performed by applying a voltage to each of the rotating wheel and an electrode which comes into contact with the molded body having a predetermined shape extruded from the die. The method for extruding a metal material according to the above item.