JPH05285532A - Method for extrusion processing - Google Patents

Abstract

PURPOSE:To efficiently produce extrusion material wherein air extraction process after upsetting can be neglected and an idle time can be reduced. CONSTITUTION:A matter on which a circular hole 5 larger in diameter than a container billet hole 1a is formed on a plate shape material having a prescribed thickness is used as a discard cutting shear 4. This shear 4 is inserted between a container 1 and an extruding tool 2 so that its circular hole 5 is concentric with a billet hole 1a, the billet B is upset under such a state, continuously with it, begins to be extruded without extracting the air. After the extrusion ends, the container 1 is backed to lower the shear 4 and cut the discard B.

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 extruded material such as aluminum.

[0002]

2. Description of the Related Art Conventionally, extrusion molding of aluminum extruded material has been performed as follows. That is, as shown in FIG. 4 (a), first, the billet hole (51) of the container (51) is
Prepare a billet (B) having a diameter slightly smaller than that of a) and load it into the container (51). The diameter of the billet (B) is formed to be slightly smaller than the diameter of the container billet hole (51a) in order to facilitate the charging of the billet (B).

Then, as shown in FIG. 4 (b),
Perform upset. That is, the stem (52) is driven forward to press the billet (B) at a pressure lower than the extrusion pressure (for example, 80 Kgf / mm ² ) to fill the container billet hole (51a) with the billet metal. Billet (B) in container (51) in this upset process
Since the front and rear end surfaces of the billet come into contact with the extrusion tool (53) and the dummy (54), respectively, they are transformed into a beer barrel shape. The entire area in the direction comes into close contact with the inner peripheral surface of the billet hole (51a). The billet hole (51
a) The contact area of the billet (B) to the inner peripheral surface expands toward both ends.

At this time, the air existing between the billet hole (51a) and the billet (B) on the rear end side of the billet (B) passes through the gap between the dummy (54) and the billet hole (51a). The air, which is discharged to the outside, exists between the billet hole (51a) and the billet (B) on the front end side of the billet (B), but the air is present after the front end surface of the container (51) and the extrusion tool (53). Since the end face and the end face are in close contact with each other in an airtight state, the end face cannot escape to the outside. Therefore, at the end of the upset filled with the billet metal, a high-pressure air pool (a ) Is formed. If the process proceeds to extrusion as it is, there is a high risk that the air in the air pocket (a) will be caught toward the forming hole of the extrusion tool (53) by the action of the metal flow.
Therefore, a defective extruded material may be molded.

Therefore, after the upsetting process, air is removed from the air reservoir (a). Conventionally, this air bleeding has been performed by retracting the container (51) and the stem (52) rearward, as shown in FIG. As a result, the air in the air reservoir (a) is released.

After the air venting process, as shown in FIG. 5 (d), the container (51) is moved forward to bring it into close contact with the extrusion tool (53), and then, as shown in FIG. 5 (e). Extrusion is performed as shown, and as shown in FIG. 5 (f), the container (51) is retracted leaving a certain amount of discard (D), as shown in FIG. 5 (g). Then, the discard (D) is cut off with a shear (56). The shear (56) has a cutting edge at the lower edge.

After that, for example, the container (51)
Then, the next billet is charged, and the same steps as described above are carried out to carry out the extrusion in the pushing joint state.

[0008]

However, in the method of performing air bleeding after the upset by retracting the container (51) as described above, the idle time in one cycle of extrusion becomes long, and the extrusion process is produced. There was a drawback that it could not be implemented with good performance.

In view of the above-mentioned conventional problems, the present invention omits the air venting step after the upset, shortens the idle time in one cycle of extrusion, and thus can improve productivity. The purpose is to provide a processing method.

[0010]

According to the present invention, as a shear for cutting a disc, a plate-shaped material having a predetermined thickness is provided with a circular hole having a diameter larger than that of a billet hole of a container. Using a cutting blade at the peripheral edge of the circular hole, the shear is sandwiched between the container and the extrusion tool in a state in which the circular hole is arranged concentrically with the billet hole of the container, and the state In the above, the billet is upset in the container billet hole, the extrusion is subsequently performed, and after the extrusion, the shear is moved in a plane orthogonal to the extrusion direction, so that the discard is cut off by the circular hole peripheral cutting blade portion. The gist is an extrusion processing method characterized by the following.

[0011]

In the above method, as a shear for cutting discard, a plate-like material having a predetermined thickness provided with a circular hole having a diameter larger than the diameter of the billet hole of the container is used. In a mode in which the container is arranged concentrically with the billet hole of the container, it is sandwiched between the container and the extrusion tool, and the upset is performed in that state, so that the air receives most of the action of metal flow during extrusion. At the position adjacent to the inner peripheral portion of the shear circular hole on the radially outer side of the empty billet hole, it is biased toward the container side. Therefore, even if the air bleeding process such as retracting the container is omitted and the process proceeds to the extrusion as it is, the air in the air reservoir is not caught in the extrusion tool side during the extrusion, and a defect does not occur in the extruded material.

Moreover, since the inner peripheral edge of the shear circular hole is formed on the cutting blade, after the extrusion is completed, the discard is cut off by simply moving the shear in a plane orthogonal to the extrusion direction. The discard cutting process is also efficiently performed. It should be noted that the discard in the shear circular hole may be slid so as to be removed using a cylinder device or the like.

[0013]

The method of the following embodiments of the present invention will be described.

In the extrusion processing apparatus shown in FIG. 1 (a), (1) is a container which is held so that it can be driven to move back and forth in the front-rear direction. (2) is an extrusion tool such as a porthole die, which is held by a die slide (not shown) so as to be concentric with the container (1) at a predetermined position in front of the container (1). (3) is a stem, and the billet (B) inserted into the billet hole (1a) of the container (1)
Is connected to a press machine so as to apply pressure from the rear side, and is held so that it can be driven back and forth. Further, (4) is a shear for cutting discard, which is arranged between the extrusion tool (2) and the container (1) in a manner adjacent to the extrusion tool (2) and is driven in the vertical direction. It has been done.

This shear (4) is shown in FIG. 1 (a) (b).
As shown in FIG. 3, a circular hole (5) is formed in the surface of a plate-shaped material having a predetermined thickness. The circular hole (5) is formed to have a diameter larger than that of the billet hole (1a) of the container (1). Of course, even though the diameter is large, the circular hole (5) is arranged concentrically with the container billet hole (1a), and in that state, the shear (4) is sandwiched between the container (1) and the extrusion tool (2). It goes without saying that in the state, the inside of the circular hole (5) is in a range where it is shielded from the outside.
The inner peripheral surface of the circular hole (5) is formed so as to be substantially orthogonal to the rear end surface of the extrusion tool (2), and the inner peripheral edge portion of the circular hole (5) on the extrusion tool (2) side is formed. , A blade portion (6) for cutting discard.

The method of this embodiment is carried out as follows using the above-mentioned extrusion processing apparatus. That is, as shown in FIG. 2 (a), the shear (4) is set to a height such that the circular hole (5) and the container billet hole (1a) are in a concentric state. By advancing the container (1), the shear (4) is sandwiched between the extrusion tool (2) and the container (1) in a pressure contact state.

In this state, as shown in FIG. 2 (b), the stem (3) is driven forward, and the billet (B) inserted into the billet hole (1a) of the container (1) is pressed. , And upset. By this upset, the billet (B) is initially transformed into a beer barrel shape, and a part of the air existing between the outer peripheral surface of the billet (B) and the inner peripheral surface of the billet hole (1a) is a dummy. The remaining air is discharged rearward through the gap at the peripheral edge of (7), while the remaining air is sheared circularly located (5) radially outside the billet hole (1a) that is hardly affected by the metal flow during extrusion. The air pool (A) is formed in a state of being biased toward the container (1) side at a position adjacent to the inner peripheral portion of the, and the air pool (A) is concentrated there. Therefore, the plate thickness of the shear (4) and the circular hole (5)
The diameter of is also set so that such an action can be performed most effectively.

Thereafter, the air venting step is omitted, and the extrusion is performed as shown in FIG. During this extrusion, the air in the air reservoir (A) is hardly affected by the metal flow and is not entrained on the extrusion tool (2) side.

Then, the extrusion is stopped with a certain amount of discard (D) left, and as shown in FIG. 3 (D), the container (1) and the stem (3) are driven backward.
Then, as shown in FIG. 3 (e), the shear (4)
Is driven downward as it is, the discard (D) is cut down by the upper half cutting blade part (6) of the inner peripheral edge of the circular hole (5), and the cylinder device (8 ), The discard (D) in the shear circular hole (5) is pushed down.

After that, the shear (4) is raised to adjust the height of the circular hole (5) so as to be concentric with the container billet hole (1a), and the next billet is the same as above. Extrude according to the procedure and repeat extrusion extrusion.

[0021]

As described above, according to the extrusion processing method of the present invention, a circular hole having a diameter larger than the diameter of the billet hole of the container is provided in the plate-shaped material having a predetermined thickness as a shear for cutting discard. In the mode in which the circular hole is arranged concentrically with the billet hole of the container, it is sandwiched between the container and the extrusion tool, and the upset is performed in that state. , Is concentrated and concentrated on the container side at a position adjacent to the inner peripheral portion of the shear circular hole on the radially outer side of the billet hole which is hardly affected by the metal flow during extrusion. Therefore, it is not necessary to remove the air in this portion.
Therefore, the air venting step can be omitted, the idle time in one cycle of extrusion can be shortened, and productivity can be improved.

Moreover, since the inner peripheral edge of the shear circular hole is formed on the cutting blade, discard cutting after the extrusion is completed by moving the shear in a plane perpendicular to the extrusion direction, and discarding The cutting can also be performed efficiently.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of an extrusion processing apparatus used in a method of an embodiment, and FIG. 1B is a front view of a shear for cutting a discard.

2A and 2B show an example method, wherein FIG. 2A is a sectional view of an extrusion processing apparatus showing an initial standby state, FIG. 2B is the same sectional view showing an upsetting step, and FIG. 2C is an extruding step. It is the same sectional view shown.

FIG. 3 (d) is a cross-sectional view of the extrusion processing device showing a state in which extrusion is completed with a certain amount of discard left and the container and stem are retracted, and FIG. 3 (e) shows a discard cutting process. FIG.

4A and 4B show a conventional method, wherein FIG. 4A is a sectional view of an extrusion processing apparatus showing an initial standby state, FIG. 4B is a sectional view showing the upsetting process, and FIG. FIG.

FIG. 5 (d) is a cross-sectional view of the extrusion processing device showing a state in which the container and the stem have been advanced after bleeding air, FIG.
Is the same cross-sectional view showing the extrusion process, Fig. (F) is the same cross-sectional view showing the state where the extrusion is completed with a certain amount of discard left, and the container and stem are retracted. Fig. (G) is the discard cutting process FIG.

[Explanation of symbols]

 1 ... Container 1a ... Billet hole 2 ... Extrusion tool 4 ... Discard cutting shear 5 ... Circular hole 6 ... Cutting blade B ... Billet hole D ... Discard A ... Air pool

Claims (1)

[Claims] 1. As a shear for cutting a discard, a plate-shaped material having a predetermined thickness is provided with a circular hole having a diameter larger than the diameter of a billet hole of a container, and a peripheral edge of the circular hole is used as a cutting blade. The shear is sandwiched between the container and the extrusion tool in a mode in which the circular hole is concentric with the billet hole of the container, and in that state, the billet is upset in the container billet hole. Subsequent extrusion,
After extrusion, by moving the shear in a plane perpendicular to the extrusion direction, the discard is cut off by the circular hole peripheral edge cutting blade portion, which is an extrusion processing method.