JPH01170516A - Extrusion die for hollow section - Google Patents

Abstract

PURPOSE:To prevent the temperature near a bearing part of a male die from rising as possible, to restrain tears from occurring and to improve the extruding rate by providing a space part for supplying refrigerant in a forming projection part having a bearing part of a male die. CONSTITUTION:When refrigerant such as N2 gas, etc., is circulated to the spacer part 27 provided in the forming projection part 21 of a port-hole male die 2, the neighborhood of the bearing 23 of the male die is cooled, therefore, the rise of temperature near the bearing part 23 of the male die due to the work heat in time of extruding operation is constrained. Further, since the internal circumferential surface in the space part is formed in the shape of an irregular surface 27a like a fin, the contact area with the refrigerant is increased, more effective cooling effect is obtained and the rise of temperature is constrained more and more.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an extrusion die for hollow shapes such as pipes, hollow materials, semi-hollow materials, etc., and particularly to an extrusion die that can be suitably used for manufacturing hollow aluminum shapes. .

BACKGROUND ART AND PROBLEMS The extrusion of hollow shapes as described above is generally carried out using a porthole die consisting of a combination of a female die and a male die.

By the way, in such a porthole die, the temperature near the male and female bearing parts increases due to the generation of processing heat during extrusion processing.

Therefore, even if the temperature near the bearing part increases, the female mold can dissipate heat to the surrounding space, so the temperature increase is relatively small, whereas the male mold is surrounded by molding material in the container, so the temperature rises. The rise is inevitable. As a result, there is a temperature difference between the male and female bearing parts, and the temperature of the extruded material such as aluminum passing through the molding gap formed between the male and female bearing parts is also close to that of the female bearing part. The temperature is higher on the inside near the male bearing part than on the outside, which causes cracking on the inner surface of the extruded material, making it impossible to obtain a high-quality hollow shaped material.

Moreover, in the case of hollow shapes with internal screw holes, mohair, etc.
There was also a drawback that the extrusion speed could not be increased due to cracking.

The present invention has been made in order to eliminate such drawbacks, and it is possible to prevent the temperature rise in the vicinity of the male bearing part as much as possible, suppress the occurrence of cracking, and improve the extrusion speed. The purpose is to provide an extrusion die.

Means for Solving the Problems In order to achieve the above object, the present invention, as shown in the drawings, involves extrusion of a hollow profile consisting of a combination of a female porthole die (1) and a male porthole die (2). In the die (A), a refrigerant supply space (27
) is formed, and the inner peripheral surface of the space is formed into a fin-like uneven surface (27a).

By circulating and supplying a refrigerant such as N2 gas to the space (27) provided inside the molding convex part (21) of the male die (2), the bearing part (23) of the male die is formed.
Since the vicinity is cooled, the temperature rise in the vicinity of the male bearing part due to processing heat during extrusion processing is suppressed. Furthermore, since the inner circumferential surface of the space is formed into a fin-like uneven surface (27a), the contact area with the refrigerant increases, a layer-effective cooling effect is exerted, and the temperature rise is further suppressed. .

Example Next, the structure of the present invention will be explained based on illustrated embodiments.

The die (A) shown in Figs. 1 to 4 is for manufacturing a square cylindrical hollow member (X) having a hollow part (c) inside as shown in Fig. 5. .

As shown in FIG. 1, the die (A) is composed of a female porthole die (1) and a male porthole die (2).

The female mold (1) has a protruding edge (12) for positioning on the periphery of the joint surface (11), and a concave inflow portion (13) through which the molding material flows into the center of the joint surface (11). Furthermore, the inflow portion (13) has an extrusion hole (14) having a rectangular cross section in the center thereof and passing through the female die in the thickness direction. Moreover, the peripheral surface on the inlet side of this extrusion hole (14) is the bearing part (1
5), and the peripheral surface on the outlet side is a relief part (IB) following the bearing part (15).

On the other hand, the male mold (2) has a molding convex part (21) with a square cross section in the center thereof, and a plurality of introduction holes (2) for introducing molding material at positions around the convex part (21).
2). A bearing part (23) is formed on the circumferential surface of the distal end of the molded convex part (21), and is opposed to the bearing part (15) of the female mold (2) on the inside.

Furthermore, inside the molded convex part (21), there is a space (27) with a substantially square cross section that opens at the tip surface of the molded convex part (21).
) is bored to a depth near the base end of the space (2)), and a refrigerant passage (28) that communicates with the bottom of this space (2)) and opens on the outer circumferential surface of the male mold separates the introduction holes (22) from each other. It is provided so as to penetrate one partition wall (24). This refrigerant passage is a passage for supplying a refrigerant such as N2 gas from an external supply device (not shown) to the space (27) through the passage entrance (28a) on the outer peripheral surface of the male die during extrusion processing,
This supplied refrigerant causes the male bearing part (23
) It is designed to cool the surrounding area and suppress the temperature rise. In addition, in order to make the cooling effect near the bearing part, in other words, the heat dissipation effect of machining heat as excellent as possible, the inner circumferential surface of the space (27) has a cross-sectional corrugated shape with a large number of fins. It is formed in a fin-like uneven surface (27a) to increase the surface area.

Therefore, the above female type (1) and male type (2) are male type (2).
A positioning step (
26) is fitted into the edge (12) of the female die (1), thereby being assembled into a die. In such a combined state, the molding convex portion (2) of the male mold (2)
1) The tip faces the extrusion hole (14) of the female mold (1), and the male and female bearing parts (15) (23) are arranged facing each other with an annular molding gap (3) interposed therebetween. ing.

In the die (A), the molding material such as aluminum billet heated in the container of the extruder flows into the introduction hole (22) of the male die (2) due to extrusion pressure. The molding material that has flowed into the introduction hole (22) is then transferred to the female mold (1).
After passing through the inflow part (13) and merging here,
Bearing parts (15) (2) of both male and female types (1) (2)
3) is extruded from the molding gap (3) between the molding parts 3) and molded into a rectangular hollow shape member (X) as shown in FIG. During this extrusion process, the space (27) provided in the male molding convex part (21)
3, the refrigerant passage entrance (28a
), a refrigerant such as N2 gas is continuously introduced and supplied through the refrigerant passage (28).

The cooling effect of this refrigerant cools the vicinity of the bearing part (23) of the molded convex part (21), thereby suppressing a temperature rise caused by extrusion heat. Moreover, since the inner circumferential surface of the space (27) is formed into a line-shaped uneven surface (27a) and the surface area is expanded, heat dissipation from the vicinity of the bearing part to the space (2γ) is more efficient. It is operated by
The temperature rise near the bearing part (23) is further suppressed.

Effects of the Invention As described above, the die for extruding hollow shaped materials according to the present invention has a refrigerant supply space formed inside the molding convex portion having the bearing portion of the male die, so that extrusion processing is not possible. By sometimes supplying a refrigerant to this space, it is possible to suppress a rise in temperature near the male bearing part due to extrusion heat. Furthermore, since the circumferential surface of the space is formed into a fin-like uneven surface, it is possible to further improve the heat dissipation efficiency in the vicinity of the male bearing part, and it is possible to further suppress a temperature rise. As a result, the temperature difference near the male and female bearing parts can be reduced, so the temperature distribution of the extruded material passing through the molding gap between both bearing parts can be made uniform, and the temperature difference on the male bearing part side of the extruded material can be made uniform. It is possible to prevent the occurrence of cracks, etc. on the surface, that is, the inner surface, and it is possible to provide a hollow shaped material with high commercial value. Furthermore, since no cracking occurs, the extrusion speed can be increased and the productivity of hollow shaped materials can be improved.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the die according to the present invention, FIG. 1 is a partially cutaway perspective view showing a female die and a male die separated, and FIG. An enlarged perspective view of the protruding piece of the female die, FIG. 3 is a vertical sectional view of the main part of the die, FIG. 4 is a sectional view taken along line IV-■ in FIG. 3, and FIG. 5 is the above-mentioned FIGS. 1 to 4. FIG. (A)...Dice, (X)...Hollow shape material, (1)...
... Female type, (15) ... Bearing part, (2) ...
Male mold, (21)...Molding convex part, (23)...Bearing part, (27)...Space part, (27a)...Fin-shaped uneven surface, (3)...Molding gap . Sheep: FJ > lyoj Figure 1 Figure 2/X Figure 5

Claims (1)

[Claims] In a die for extruding a hollow shaped material consisting of a combination of a female porthole die and a male porthole die, a space for refrigerant supply is formed inside a molding convex portion having a bearing portion of the male die, and a space A die for extruding a hollow shaped material, the inner circumferential surface of which is formed into a fin-like uneven surface.