JPH11138210A - Extruding tool for indirect extrusion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the surface quality of an extruded material and to prevent variation in dimensions in indirect extrusion. SOLUTION: On the circumference of the outer peripheral surface 23 of the straight part of a die ring 22 for indirect extrusion, plural flat parts or grooves are formed so as to partially increase the clearance with the inside wall of a container 4 and by flowing out metal during extruding and trapped air in the vicinity of the inside wall of the container from this clearance, the surface of the extruded material is prevented from entraining them. Frictional resistance with the inside wall of the container 4 is reduced in the flat part or groove part, so the clearance with the inside wall of the container 4 can be reduced by making the outside diameter itself of the outer peripheral surface 23 larger corresponding to the decrease. As a result, the deviation between the die ring 22 during extruding and the axial center of the container 4 becomes smaller and the variation in the dimensions of the extruded material is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion tool used for indirectly extruding a metal such as aluminum or an aluminum alloy.

[0002]

2. Description of the Related Art For example, as shown in FIGS. 7A and 7B, a die 1 is housed in a die ring 2 and this is combined with a die stem 3 by indirect extrusion of aluminum or aluminum alloy. Alternatively, the die 11 is combined with the die stem 3 and this is connected to the extruder container 4.
The billet metal B loaded in the container 4 is pushed backward from the die 1 or 11 through the die stem 3. In FIG. 7, reference numeral 5 denotes a seal block.

[0003]

However, in the conventional extrusion tool as described above, the dimensions and surface quality of the extruded material E extruded from the die 1 or the die 11 become stable over the entire longitudinal direction. There was a disadvantage that it was difficult. This is mainly due to the following reasons. The extrusion tool (die 1, die ring 2, die 11) mounted on the stem 3 advances in the container 5, and the billet metal B in the container 5 is extruded from the die 1 or the die 11, but at this time, during extrusion, Since the entire billet metal B is extruded as an extruded material E from the center portion to the outer peripheral portion, impurities, air, and the like near the inner wall of the container 5 enter the surface of the extruded material E as defects. The outer diameter of the outer peripheral surface (straight portion) of the die ring 2 or the die 11 is the container 5
Is formed to be slightly smaller than the inner diameter of the inner peripheral surface, and there is a gap (clearance) between the two. This gap reduces the frictional resistance when the extrusion tool moves forward or backward in the container 5. Due to this gap, both axes move during the extrusion process, and this causes a change in the dimension of the extruded material E,
In particular, it promotes uneven wall thickness in extruding a tube. These were the main factors, and as described above, the dimensions and surface quality of the extruded material E were difficult to be stable over the entire length direction.

[0004] In view of the problems of the prior art, an object of the present invention is to provide an extrusion tool capable of indirectly extruding an extruded material having appropriate dimensions and surface quality stably over the entire length.

[0005]

According to the present invention, there is provided an extrusion tool for indirect extrusion according to the present invention, in which an outer peripheral surface facing a container inner wall of a die or a die is formed with a portion where a gap with the container inner wall is partially large. , Which extend in the axial direction. The portion where the gap with the inner wall of the container is partially large is, for example, a flat portion or a concave groove formed on a circular outer peripheral surface of a die or a die. In addition, this gap (gap with the inner surface of the container)
Is preferably set to a size that allows the metal being extruded near the inner wall of the container to flow out.

[0006] Due to the presence of such a concave groove or the like between the outer surface of the die or die and the inner wall surface of the container, during extrusion, impurities near the inner wall of the container and sealed air are removed from this clearance. They can be drained and can be prevented from mixing as defects on the surface of the extruded material. In addition, by increasing the gap at a location such as a concave groove, the frictional resistance with the inner wall surface of the container is reduced.Therefore, without increasing the frictional resistance as a whole, at a location other than the concave groove or the like on the outer surface of the die or die. The clearance (clearance) between the inner wall of the container and the inner wall of the container can be reduced, so that the deviation between the axes of the two can be reduced and the adverse effect on the dimensions of the extruded material can be reduced. Do). As a result, the extruded material has stable and appropriate dimensions and surface quality over its entire length.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an extrusion tool according to the present invention will be described more specifically with reference to FIGS. FIG. 1 relates to an apparatus for indirectly extruding a round bar material, and shows a die 21 having a circular die hole and a die ring 22 for accommodating the die 21 as an extrusion tool. The billet metal B loaded in the container 4 is pushed backward. The outer peripheral surface (straight portion) 23 of the die ring 22 facing the inner wall surface of the container 4 has a portion where the gap with the container inner wall partially increases over the entire length of the straight portion 23 at several places in the circumferential direction (23a described later). , 23
b) is formed, and impurities and sealed air near the inner wall of the container 4 flow out from the gap.

[0008] Such a die 21 and a die ring 22
When viewed in the II direction of FIG. 1, for example, FIG.
The shape is as shown in FIG. (A) is a shape in which a circular outer peripheral surface of the straight portion 23 is formed into a flat surface 23a at a plurality of positions (eight positions at equal intervals), and a gap is formed between the flat surface 23a and the inner wall surface of the container 4. FIG. 2B is a diagram in which a number of grooves 23b are formed at equal intervals on the circular outer peripheral surface of the straight portion 23, and a gap is formed between the groove 23b and the inner wall surface of the container 4 (FIG. 2 is exaggerated). Is drawn). On the other hand, the outer diameter itself (the portion other than the flat surface 23a or the groove 23b) of the circular outer peripheral surface of the straight portion 23 is made larger than before, and the difference from the inner diameter of the container 4, that is, the clearance between the inner wall surface of the container 4 (clearance) ) Is small, and the core accuracy of the die 21 and the container 4 of this extruder can be maintained at a high level.

The location where the gap between the outer peripheral surface of the straight portion 23 of the die ring 22 and the inner wall of the container 4 is partially large, that is, in the above example, the dimensions of the flat portion 23a and the groove 23b are determined by the inner wall of the container 4 during extrusion. It is necessary to make it possible for the nearby impurities and the sealed air to effectively flow out, but the shape thereof is not limited to the example shown in FIG.
The semicircular groove shown in FIG. 3 (a), the large and small grooves shown in FIG. 3 (b), and the like can be appropriately determined according to the type of the metal to be extruded. I just need. Further, the shape is not limited to one type but may be a combination of a plurality of types.

FIG. 4 also relates to an apparatus for indirectly extruding a round bar material, in which a die 31 having a circular die hole is shown as an extrusion tool, and this is combined with the tip of the stem 3 and pushed into the container 4. The billet metal B loaded in the container 4 is extruded backward. The outer peripheral surface (straight portion) 33 of the die 31 facing the inner wall surface of the container 4 is formed at several locations in the circumferential direction where the gap with the inner wall of the container partially increases over the entire length of the straight portion 33. . Straight part 3
The shape of the outer peripheral surface of 3 and others may be the same as the apparatus shown in FIG.

FIG. 5 relates to an indirect extruder for a round pipe. A die 41 having a circular die hole and a die ring 42 for accommodating the die 41 are shown as an extrusion tool. The pipe E is formed by extruding the billet metal B loaded into the container 4 by being pushed into the container 4 and cooperating with the fixed mandrel 44 provided at the center of the die hole. The outer peripheral surface (straight portion) 43 of the die ring 42 facing the inner wall surface of the container 4 is formed at several places in the circumferential direction where the gap with the inner wall of the container partially increases over the entire length of the straight portion 43. I have. The shape of the outer peripheral surface of the straight portion 43 and others may be the same as the device shown in FIG.

FIG. 6 also relates to an indirect extruder for a round pipe. A die 51 having a circular die hole is shown as an extruding tool. In cooperation with the fixed mandrel 54 installed in the center of the hole, the billet metal B loaded in the container 4 is extruded and the pipe E
Is molded. The outer peripheral surface (straight portion) 53 of the die 51 facing the inner wall surface of the container 4 is formed at several places in the circumferential direction where the gap with the inner wall of the container partially increases over the entire length of the straight portion 53. . FIG. 1 shows the shape of the outer peripheral surface of the straight portion 53 and others.
May be the same as the device shown in FIG. Although the examples of the round bar and the round pipe have been described above, the extrusion tool of the present invention can be applied to solid and hollow sections having various cross-sectional shapes. In the above example, a single-acting indirect extrusion press was described, but it goes without saying that the extrusion tool of the present invention is similarly applied to a double-acting indirect extrusion press.

[0013]

According to the present invention, by forming a flat surface or a groove on the outer peripheral surface of a die or a die ring, an extruded material having an appropriate size and surface quality which is stable over the entire length direction can be obtained by indirect extrusion. be able to.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of an extrusion tool according to the present invention.

FIG. 2 is a view taken along the line II.

FIG. 3 is a view showing another example of a concave groove formed in a straight portion of a die ring.

FIG. 4 is a sectional view showing the structure of another extrusion tool according to the present invention.

FIG. 5 is a sectional view showing the structure of still another extrusion tool according to the present invention.

FIG. 6 is a sectional view showing the structure of still another extrusion tool according to the present invention.

FIG. 7 is a sectional view showing the structure of a conventional extrusion tool.

[Explanation of symbols]

21, 31, 41, 51 Dies 22, 42 Diling 23 Outer peripheral surface (straight portion) facing the inner wall of the container of the die ring 23a Flat surface of the outer peripheral surface 23b Groove of the outer peripheral surface 3 Stem 4 Extrusion container

Claims (3)

[Claims] 1. An indirect method characterized in that a portion where a gap with the container inner wall is partially formed is formed on an outer peripheral surface of the die ring or the die facing the container inner wall, and the portion extends in the axial direction. Extrusion tool for extrusion. 2. The extrusion tool for indirect extrusion according to claim 1, wherein the location is a flat portion or a groove formed on a circular outer peripheral surface. 3. The extrusion tool for indirect extrusion according to claim 1, wherein the metal being extruded near the inner wall of the container flows out of the gap at the location.