JPS62263822A - Extrusion forming method for hollow or semi-hollow stock and extrusion forming metal die for extrusion forming - Google Patents

Abstract

PURPOSE:To reduce variance in sectional dimensions of products by making a preliminary forming die hole being roughly resemble or similar to the final sectional shape of hollow stocks, etc. and a flow straightening inside cavity part which communicates with the above hole and has a larger section than that of the hole. CONSTITUTION:An extrusion forming metal die 4 consisting of a port 5 and a die 6 is installed at the aperture front end of a container 1 and a back de 7 and a bolster 8 are also installed with their axis being aligned. A preliminary forming die hole 15 which has a similar sectional shape to that of the final semi-hollow stock and communicates with a welding chamber 10 is made in the die 6 and an annular flow straightening inside cavity part 16 having a larger section than that of the die hole 15 is made in front of the die hole 15. A billet 2 divided in a port hall 9 is preliminarily formed by the hole 15 and the metal flow of the billet 2 is equalized by the part 16. Therefore, variance in the sectional dimensions of a product formed by the final die hole 17 is reduced.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an extrusion method for hollow or semi-hollow shapes made of metal materials such as aluminum, particularly elongated shapes, and a filter extrusion method used therein. Regarding molds.

(Prior Art) Conventional 1 For example, in the extrusion molding method of a hollow elongated member from an aluminum billet, a bow 1- having a double-walled boat hole and a bow 1- with a double-walled boat hole are used as extrusion molds attached to the i'+ii ends of a container. , an annular welding chamber communicating with the boat hole, and a mold hole corresponding to the final extruded product communicating with the welding chamber. The billet is pressurized from the rear to the extrusion mold, and the aluminum material is diverted into the boat hole.
Next, the diverted aluminum material is welded into a ring shape in the welding chamber, and then the aluminum material welded into a ring shape is immediately continuously extruded from the mold hole into a hollow member having a predetermined cross section. The method of doing so is generally known. However, in this extrusion molding method using a conventional extrusion mold, there are large variations in cross-sectional dimensions at each position between the extrusion start end and the extrusion end end of the hollow elongated shape obtained from one billet. There was a drawback that appeared. This is because the billet 1~ is immediately extruded from the container, boat hole, and welding chamber through the mold hole under high pressure, so there is a significant difference in the direction, speed, etc. of metal flow between each part inside the aluminum material. Unevenness,
Extrusion molding is carried out with fluctuations included, and the direction and speed of the metal flow inside the aluminum material until the billet is extruded under pressure must be controlled economically from the start of extrusion to the end of extrusion. This is thought to be due to considerable fluctuations.

Conventionally, as a method for improving such variations in cross-sectional dimensions of extruded materials, immediately after pressurizing the billet and extruding it from the die hole, the extruded materials are further passed through a drawing die to shape the cross-section into a predetermined shape. , Tsutsumi proposed a method of rectifying the dimensions by four squares (Japanese Patent Publication No. 10700/1973).

However, in this conventional method, passing through the forming die after extrusion is performed by pulling out the extruded material, so it can only be used for extruded shapes that have a specific cross-sectional shape that can be pulled out. There were some difficulties, such as the complicated shape of the wall and the fact that the dimensions had to be corrected using a solid wall.

(Problems to be Solved by the Invention) ° The first invention of the present application is an extrusion molding method that can slightly suppress variations in cross-sectional dimensions at each position from the extrusion start end to the extrusion end end of a hollow or semi-hollow material. The purpose is to provide a method.

A second aspect of the present invention aims to provide an extrusion mold for use in the extrusion molding method, which enables effective implementation of the extrusion molding method.

(Means for Solving the Problems) In order to achieve the above object, the extrusion molding method of the first invention of the present application includes, in the step of pressurizing a billet and extrusion molding it into a shape, the pressurized billet, A step of sequentially preliminarily imparting a cross-sectional shape roughly similar to or similar to the cross-sectional shape of the final hollow or semi-hollow shape to be formed, and then a metal flow of the metal preliminarily imparted with the cross-sectional shape. rectifying the rectified metal; and then extruding the rectified metal into a hollow or semi-hollow section of final cross-sectional shape.

The extrusion molding die of the second invention of the present application comprises: a preforming mold hole that is roughly similar or similar to the cross-sectional shape of the final hollow or semi-hollow material to be molded, and the preforming mold hole described above. and a rectifying inner retaining portion communicating with the preform hole and having a wider cross section than the preform hole.

and a final mold hole communicating with the rectifying lumen.

It consists of: In the present invention, a hollow shaped material refers to a cylindrical shaped material having a circular, square or irregular cross section, and a semi-hollow shaped material refers to a cylindrical shaped material having a partially opened section such as a C-shaped cross section or a square C-shaped shape. Refers to wood. An extrusion molding method for a hollow or semi-hollow aluminum profile and an example of an extrusion mold used therein will be described below with reference to the drawings.

For convenience, the extrusion mold will be explained first. In Fig. 1, an aluminum billet (2) heated to a predetermined temperature is inserted into a container (1), the billet (2) is pressurized from the rear in the t''ni direction by a stem (3), and the container ( At the front end of the opening of 1), an extrusion mold (4) consisting of a boat (5) and a die (6), a back die (7), and a bolster (8) are arranged in an overlapping state with their axes aligned with each other. It is.

The boat (5) of the extrusion mold (4) has a porthole (9) with a fan-shaped cross section along an arc centered on the axis of the disc-shaped body as shown in Figure 2.3. ... (5 holes in the figure) are passed through parallel to the axis line at equal intervals, and the above-mentioned bore 1-hole (
9) A welding chamber (10) consisting of an annular inner IP3IJ11 communicating with... is provided concentrically with the port pole group, and a mandrel ( ti) is provided protrudingly. - The welding chamber (10) described in F has an inner diameter slightly smaller than the inner diameter of the group of portholes (9), and an outer diameter of about three-fifths of the outer diameter of the group of portholes. be. The mandrel (11) has a large diameter part (12) having the same diameter as the inner diameter of the welding chamber (10) at its base, and a small diameter part (13) about half the diameter from the base to the tip. ) is formed through a step (14) substantially perpendicular to it.

The die (6) has a cross section similar to the cross-sectional shape (C-shape in this example) of the final semi-hollow material to be formed, between the outer peripheral surface of the large diameter portion (12) of the mandrel (11). A preform hole (15) having a shape (in this example, a circle larger than the C shape) and communicating with the welding chamber (10) is formed, and the preform hole (15) has a shape in this example. Both the inner and outer diameters of the welding chamber (1
0). Next, in front of the preforming mold hole (15), the preforming mold hole (1
5) and forms an annular rectifying lumen (16) having a wider cross section than the mold hole (15).

In one example, the rectifying lumen (16) has an outer diameter equal to the outer diameter of the preform hole (15) and an inner diameter smaller than the inner diameter. Furthermore, in front of the rectifying lumen (16).

In this example, the final mold hole (with a C-shaped cross section) communicates with the rectifying lumen (16) between the mandrel small diameter part (13) and the rectifying bore part (16).
In this example, the mold hole (17) has an outer diameter smaller than the outer diameter of the preforming mold hole (15) and the rectifying inner cavity (16), and an inner diameter of the rectifying inner lumen (16). 16) is approximately equal to the inner diameter.

An example of an extrusion molding method for a semi-hollow member having a C-shaped cross section using the extrusion mold (4) as described above will be described. The billet (2) inserted into the container (1) and heated to a predetermined temperature is continuously pressurized forward by the stem (3), and the Pireno 1-(2) is sequentially inserted into the port hole (9) from the front end. )... Divert the flow into the inside. Next, the diverted aluminum material is allowed to flow into the welding chamber (io).

Therefore, the divided aluminum materials are welded together.

Next, the welded aluminum material is sent into the preforming mold hole (15), where a circular hollow cross-sectional shape similar to and larger than the C-shaped cross section of the final semi-hollow material is sequentially preliminarily formed on the aluminum material. Give.

Next, the aluminum material is sent into the rectifier section 772 (16).

There, as the aluminum material flows from the preform hole (15) into the cold section (16) in the rectifier, which has a wider cross section, the aluminum material is subjected to high deformation pressure, deformation resistance, and frictional force. Container (1), porthole (9)...
During the flow through the welding chamber (10) and the preform hole (15), significant non-uniformities and fluctuations in the direction, speed, etc. of the metal flow that occur between each part inside the aluminum material are equalized, that is, rectified. That will happen.

Next, send the aluminum material into the final mold hole (17),
Thereupon, it is extruded into a final semi-hollow shape having a C-shaped cross section with predetermined dimensions.

The continuous extrusion of one billet (2) is completed by continuing the pressurization of the above-mentioned stylus (:3), but the billet (
2) The direction, speed, etc. of the metal flow inside the aluminum material until it is extruded under pressure vary considerably over time from the start of extrusion to the end of extrusion.

These fluctuations are also equalized by equalizing or rectifying the direction, speed, etc. of the metal flow inside the aluminum material within the rectifying bore (16) as described above.

In the obtained long extruded section having a C-shaped cross section, the variation in cross-sectional dimensions at each position from the extrusion start end to the extrusion end end was reduced to a large degree. We conducted a comparative test with a similar long extruded shape that was extruded using a conventional extrusion mold that extrudes from a welding chamber that communicates with a porthole and immediately passes through the final extrusion mold hole. It is as shown in Figures 4-1 and 4-2.

Here, the shape to be extruded from the 01 billet is No. 4-1.
The cross section shown in the lower right of the figure is C-shaped, length = 12 m, and the outer diameter of the cross section:
56+m+, opening (d): 4.6mm.

◎Extrusion was carried out continuously by sequentially blowing and splicing three billets.

The O measurement was performed on three of the obtained 12rn sections.

1m from the extrusion start end and 1m from that position, respectively.
The aperture (d) was actually measured at each position separated from the previous measurement position by the distance indicated on the horizontal axis of the graph.

In Figures 4-1 and 4-2, variations in the dimensions of the opening (d) of the profile formed by the conventional extrusion mold 1
[] is 0.36 strokes (4.88 to 4.52 m), while the variation in the dimension of the opening (d) of the profile formed by the extrusion mold of the present invention is 0.23 am. (4°96 to 4.73 m), which was a large decrease, and if you exclude the part at the start of extrusion of the first billet, it was further reduced to 0.12 mm.

Another embodiment shown in FIG. 5 is an example of a double-acting mandrel extrusion device, in which the die (6a) is placed directly at the face end of the container (la), and the long mandrel (lla) is connected to the container with its rear end. (1a) While supported at the rear, insert the mandrel into the container and project the tip of the mandrel into the die (6a);
And a cylindrical billet (2a) with a through hole in the axial center
The billet (2a) is inserted into the container (1a) while being fitted onto the mandrel (11a), and the billet (2a) is pressurized by the cylindrical stem (3a). This is an example where they are identical.

On each side, the preform holes have a larger diameter than the final mold holes, but in some cases they may have smaller diameters or approximately the same diameter.

(Effect of the invention) According to the extrusion molding method for a hollow or semi-hollow shape material of the first invention of the present application, the cross-sectional shape is roughly similar or similar to the cross-sectional shape of the final hollow or semi-hollow shape material before the final molding step. Significant non-uniformity or variation in the direction, speed, etc. of the metal flow that occurs between various parts inside the metal due to the rectification step after the rectification step, and the direction, speed, etc. of the metal flow from the start of extrusion to the end of extrusion of one billet. The extrusion rate of the final shape obtained by equalizing and averaging the temporal fluctuations of 'lfr
The variation in cross-sectional dimensions at each position between the end and the end of extrusion can be greatly reduced.

According to the extrusion molding mold of the second invention of the present application, the extrusion molding method of the first invention can be effectively carried out, and in particular, the rectifying inner cavity having a wider cross section than the preforming mold hole allows the above-mentioned Sufficiently equalize and average out unevenness and fluctuations in the direction and speed of metal flow between various parts inside the metal, as well as changes over time in the direction and speed of metal flow between the start and end of extrusion. It is possible.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially omitted vertical sectional view of an extrusion molding apparatus, FIG. 2 is an enlarged sectional view taken along the line II-II of the molding die portion in FIG. 1, and FIG. III in Figure 2
-III line sectional view, FIGS. 4-1 and 4-2 are comparison a1 constant graphs of variations in cross-sectional dimensions, and FIG. 5 is a partially omitted longitudinal sectional view of another embodiment. 4.4a...Extrusion mold, 6,6a...Die, 1
5.15a... Preforming mold hole, 16, +6a... Rectifying inner cavity part, 17.17a... Final forming mold hole. Figure 4-1 all fixed a IL place (・m) o4-
Figure 2

Claims (2)

[Claims] (1) In the process of pressurizing the billet and extrusion molding it into a shape, the pressurized billet is sequentially given a cross-sectional shape that is roughly similar or similar to the cross-sectional shape of the final hollow or semi-hollow shape to be molded. a step of preforming the metal to which the cross-sectional shape has been preliminarily imparted; a step of rectifying the metal flow of the metal that has been preliminarily given the cross-sectional shape; and a step of rectifying the metal flow of the metal that has been preliminarily given the cross-sectional shape; A method for extrusion molding hollow or semi-hollow shapes, comprising: a final forming step of extrusion molding into a shape. (2) A preform hole that is roughly similar or similar to the cross-sectional shape of the final hollow or semi-hollow material to be molded, and a rectifier that communicates with the preform hole and has a wider cross section than the preform hole. An extrusion mold comprising: a lumen; and a final mold hole communicating with the rectifying lumen.