JPH0466217A - Dies for extruding hollow material to be formed - Google Patents

Abstract

PURPOSE:To obtain the hollow shaped material to be extruded with constant wall thickness by setting the wing part for preventing the eccentricity extendedly at the projecting part of the male die, and bringing the top end part of the wing part into contact with the inner side surface of the cavity, in which the material to be formed flows, of the female die in both dies combinated state. CONSTITUTION:The dies for extruding the hollow material to be formed is composed by combining the female dies 1 with the male dies 2. Then, the wing part 12 for preventing eccentricity is set in extending state to the side direction at the projecting part 8 for forming of the male die 2. the tip part 12a of this ring part 12 is made in contact with the inner side surface of the cavity 4, in which the material to be formed flows, of the female die 1 on the state of combining both dies 1, 2. In such a way, the projecting part for forming can be prevented from being made eccentric from its central position in the cavity for forming.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is applicable to, for example, photosensitive drums, cylinder tubes,
The present invention relates to an extrusion die used when extruding hollow shaped materials used as drawn pipes, etc.

BACKGROUND OF THE INVENTION Hollow shaped materials as described above are manufactured by extrusion using a hollow die consisting of a combination of male and female dies such as a boathole die, a spike die, a bridge die, or the like. In this type of die, the molding material is extruded from a molding gap between the molding hole of the female die and the molding convex part of the male die, and the thickness of the extruded product is determined by the gap.

Problems to be Solved by the Invention However, when extrusion is repeated using these dies, the male die itself becomes warped due to the pressure applied during extrusion and other causes.
Alternatively, the molding convex portion may be further deformed.

In this case, the molding gap between the molding hole and the molding protrusion differs from the intended setting value, resulting in uneven thickness, making it impossible to obtain an extruded product with the desired wall thickness. .

This uneven thickness phenomenon is caused by extrusion being repeated a considerable number of times when extrusion is performed using a die having one forming hole and one corresponding forming convex in the center of both male and female dies. Occurs sometimes. On the other hand, in the case of a die having two or more forming holes and corresponding forming convex portions at positions eccentric from the center of both the male and female dies, the male die may be bent even when the number of extrusions is small. Alternatively, the molded convex portion may be deformed. Therefore, in the early stage when the number of extrusions is relatively small, the initially set molding gap cannot be maintained, and only an extruded product with uneven thickness can be obtained.

In this way, the uneven thickness phenomenon in hollow dies becomes a problem when extrusion is repeated a considerable number of times in the case of so-called 1-hole extrusion dies, and in the case of so-called 2-hole or more extrusion dies, This problem occurred at a relatively early stage when the number of extrusions was small.

Therefore, the present invention provides an extrusion die for extruding hollow shaped materials, which can always maintain a desired molding gap constant even if extrusion is repeated and obtain a hollow shaped material without uneven thickness. The purpose is to

As a means to solve the problem, the inventor has conducted various experiments and researches, and found that some degree of deflection of the die due to extrusion force is unavoidable. This invention was completed by focusing on the fact that even if the convex part itself is deformed, it is sufficient to maintain a constant molding gap between the convex part and the molding hole of the female die.

In this invention, the eccentricity prevention wing section is provided in the molding convex section of the male die in a lateral projecting manner, and the tip of the wing section is inserted into the molding material inflow concave section of the female die. By bringing it into contact with the side surface, eccentricity of the molding projection with respect to the molding hole is prevented, thereby preventing the occurrence of uneven thickness.

That is, the present invention provides a die for extruding a hollow profile material consisting of a combination of a female die and a male die, in which a wing portion for preventing eccentricity is provided to extend laterally on a forming convex portion of the male die, The die for extruding a hollow shaped material is characterized in that the tip of the wing portion is in contact with the inner surface of the molding material inflow recess of the female die when the two dies are combined. be.

Function: When extrusion is performed using the extrusion die described above, the male die is bent due to the extrusion pressure, and the molding convex portion tends to deform. However, since the tips of the eccentricity prevention wings extending laterally to the molding convexity come into contact with the inner surface of the molding material inflow recess of the female die, the molding convexity Eccentricity from the center position within the forming hole can be avoided. Therefore, the molding gap between the bearing part of the molding convex part and the bearing part of the molding hole part is always maintained constant, and problems such as uneven thickness do not occur.

Example The present invention will be explained below based on illustrated embodiments.

The dies according to the illustrated embodiment are used for manufacturing hollow extruded materials such as those used for photosensitive drums, and as shown in FIG. ).

The female mold (1), as shown in FIGS. 1 and 2,
A first molding material inflow recess (4) is formed in the center of one end surface of the plate-shaped main body (3), and a second molding material inflow recess (5) is formed in the center of each recess (4), and A molding hole (6) passing through the main body (3) in the thickness direction is formed in the center of the second molding material inflow recess (5).

On the other hand, the male mold (2) has a molding convex part (8) protruding from the center of one end surface of the plate-shaped main body (7), as shown in FIGS. It has a molding material introduction hole (lO) which penetrates the main body (7) in the thickness direction in a manner surrounding the periphery of the convex part (8) and is divided into a plurality of parts in the circumferential direction by the prismatic part (9). It is something.

As shown in FIG. 4, in both dies (1) and (2), the bearing part (8a) of the molding convex part (8) is connected to the bearing part (6a) of the molding hole part (6). Both dies (1) and (2) are combined in a state facing the bearing portions (6a) and (8a), thereby forming a forming gap (11) between the two bearing portions (6a) and (8a).

Although the above-mentioned structure is substantially the same as that of the conventional product, the extrusion die according to the present invention has a molding convex portion of the male die (2) as shown in FIGS. 1, 3, and 4. (8) is provided with an eccentricity prevention wing portion (12) extending in a laterally protruding manner.

This wing part (12) is used when the molding convex part (8) tends to be eccentric with respect to the molding hole part (6) due to deformation of the male die (2) due to the extrusion pressure applied during extrusion. It acts to prevent this. The wing portion (12) is designed not to impede the flow of the molding material as much as possible, and its tip portion (12a) is connected to the female die (1) in order to prevent eccentricity of the molding convex portion (8). )
It is necessary that the molding material inflow recess (4) is in contact with the inner surface of the molding material inflow recess (4) to prevent eccentricity of the molding convex part (8). The greater the number of the wing parts (12), the more excellent the eccentricity prevention effect will be, but the flow of the molding material will become worse. From this point of view, it is desirable that the number is about 3 to 6, and the width (W) of the wing section (12) is about 1/4 of the radius (R), and the thickness (T) is about 3 of the width (W). It is desirable that it be about double that. In addition, the wing portion (12) is attached to the bearing portion (8a) as much as possible from the viewpoint of preventing eccentricity of the molding convex portion (8).
) is desirable. Furthermore, the wing part (1
In order to effectively prevent eccentricity in any direction of the molding convex part (8), it is desirable that a plurality of molding protrusions (8) are extended radially, but of course, eccentricity is likely to occur due to the structure and other factors. If the die has a fixed direction, it may be extended only in that direction. In addition, in order to facilitate the combination of both dies (1) and (2), the length of each wing part (12a) is adjusted so that the tip part (1
2a) may be set in a length relationship such that it is close to and spaced from the inner surface of the molding material inflow recess (4) and comes into contact with it due to expansion due to heat during extrusion.

In this embodiment, four eccentricity prevention wing parts (12) are provided extending from the base end of the molding convex part (8) along the bridge part (9). . This wing portion (12) has a tip portion (12a) that is connected to both dies (1) (2).
) is fitted snugly into the inner surface of the first molding material inflow recess (4) of the female die (1). Note that the wing portion (12) does not necessarily have to be formed integrally with the bridge portion (9) as in this embodiment, and may be separate and independent.

In the extrusion die described above, the molding material such as aluminum billet loaded into the container of the extruder is first separated by the bridge part (9) and the eccentricity prevention wing part (12) of the male die (2). The molding material flows into the first and second molding material inflow recesses (4) and (5), joins there, and is extruded from the molding gap (11) of the male and female dies (1) and (2) to form the desired hollow extrusion molding material. (A) is formed. During this extrusion process, even if the molding convex part (8) receives an eccentric force for some reason, the wing part (12) will not come into contact with the inner surface of the first molding material inflow concave part (4). There is no chance of eccentricity. Therefore, the molding gap (11) is always kept constant, and the hollow molded material (A
) is obtained.

In the above embodiments, a die for so-called one-hole extrusion was explained as an example, but the present invention has two or more forming holes in positions eccentric from the center of both male and female dies, and a forming hole that is fitted into the male and female dies. It can also be applied to so-called two-hole extrusion dies having convex portions.

Effects of the Invention The die for extruding hollow shaped materials according to the present invention has a wing part for preventing eccentricity extending in a laterally protruding shape on the molding convex part even if the male die is bent due to the pressure during extrusion. At the same time, since the tip thereof is in contact with the inner surface of the molding material inflow recess of the female die, a situation where the molding convex part is eccentric from its center position within the molding hole is avoided. . Therefore, the molding gap between the bearing part of the molding convex part and the bearing part of the molding hole part is always kept constant, so regardless of the number of extrusions or when using an extrusion die with two or more holes. Even if there is a molding gap, it is possible to always obtain a hollow extruded molded material with a constant wall thickness that corresponds to the desired molding gap.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view showing male and female dies separated, FIG. 2 is a plan view of the female die seen from the molding material inflow side, and FIG. FIG. 4 is a plan view of the male die seen from the molding material outflow side, and FIG. 2 and FIG. 3 IV-
It is a sectional view of rV line. (1)...Female die, (2)...Male die, (
4)... Molding material inflow recess, (8)... Molding convex part, (12)... Eccentricity prevention wing part, (12a)... Tip part. That's it'i4I Te1 Geise Figure 2 Figure 3 Figure 1 Figure 4

Claims (1)

[Scope of Claims] A die for extruding a hollow material consisting of a combination of a female die (1) and a male die (2), wherein the male die (2) has a molding convex portion (8) for preventing eccentricity. A wing portion (12) extends in a laterally protruding manner, and the wing portion (12)
The tip end (12a) of the die is in contact with the inner surface of the molding material inflow recess (4) of the female die (1) when the two dies (1) and (2) are combined.
A die for extruding hollow shaped materials.