JPH07144217A - Die for extrusion of hollow product - Google Patents

Abstract

PURPOSE:POSE: To uniformize the quality by forming in a die and port a spigot part corresponding to each cavity, forming a recessed part on a face opposite from the side face of the die of the port correspondingly to each port hole and thereby preventing uneven thickness and the ununiform flow velocity of a billet. CONSTITUTION:Since a die 2 and a port 3 are joined by a spigot part 11, 12 at the center and its outer peripheral part, the center part of the port 3 is not deformed to the die 2 side nor a mandrel 7 is inclined by receiving a pressing force from a billet 9 at the time of extrusion. In addition, the recessed part 13, 14 formed in the port 3 is entered by the billet 9 when it 15 flowed in to each port hole 8A, 8B. At that time, even if the flow velocity of the billet 9 entering 8A side is faster than that of the billet 9 entering 8B side, the reduction of the billet 9 quantity flowing in the port hole 8B or the reduction of the flow velocity is prevented. Thus, a hollow extruded product is obtained for a uniform quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow product extruding die having a die and a port for simultaneously extruding a plurality of hollow extruded shapes.

[0002]

2. Description of the Related Art Extrusion molding dies of this kind used for extrusion processing of hollow extruded profile by a continuous hot extrusion machine are
Generally, it has a die and a port that are coaxially fitted and integrally coupled.

FIGS. 3 and 4 show a conventional example of a hollow product extruding die 1 for extruding and forming two hollow extruded shapes at the same time. A die 2 and a port 3 are coaxially fitted to each other and provided in these. The facing gap between the die bearing surface 2a and the port bearing surface 3a constitutes a bearing portion 5 that defines the cross-sectional shape of the hollow extruded shape member 4. Die / bearing surface 2a for defining the outer surface shape of the hollow extruded shape member 4
Is provided on the hole wall surface of the die hole 6 formed in the die 2. On the other hand, the port bearing surface 3a is
Is formed over the entire circumference of the mandrel 7 projecting from the die contact surface, and defines the inner shape of the hollow extruded shape member 4. In addition, a plurality of port holes 8 are formed in the port 3 for each of the die holes 6 and 6 forming the hollow shape members 4 and 4 on the same circumference with the die holes 6 as the center.

When the hollow extruded shape 4 is extruded, a billet 9 made of aluminum or an aluminum alloy, which is usually heated to a predetermined temperature, is loaded into a container, and an extrusion molding die 1 is installed at one end of the container. The ram inserted from above is moved forward, the billet 9 is pressed by the push plate and pushed out from the bearing portion 5.

[0005]

In the conventional hollow product extrusion die 1 described above, the port 3 is likely to bend due to the pressure applied to the billet 9 during extrusion molding, and the flow of the billet 9 tends to become non-uniform. There is a problem that the thickness dimension of the extruded shape member 4 changes (uneven thickness). That is, since the outer peripheral portion of the die side surface of the port 3 is joined to the die 2 and the central portion is separated, the central portion is deformed toward the die 2 side when the pressing force of the billet 9 by the ram is applied to each mandrel. 7 is deformed in the directions of arrows A and B. Therefore, the facing gap between the die bearing surface 2a and the mandrel bearing surface 3a of the bearing portion becomes narrower on the mandrel deformed side and wider on the opposite side. As a result, the thickness of the mandrel deformed side becomes thin, and uneven thickness occurs. Further, when the facing gap changes due to the deformation of the port 3, the resistance of the deformation side bearing portion becomes large and the resistance of the opposite side becomes small,
The flow velocity of the billet 9 flowing into each die hole 6 is low on the port deformation side and high on the side opposite to the deformation side. Therefore, not only the deformation of the mandrel 7 is further expanded and amplified by the difference in flow velocity of the billet 9, in other words, the difference in pressure, but also the flow velocity control of the billet 9 becomes difficult. Furthermore, generally, the surface of the port 3 on the side opposite to the die 2 is formed into a flat surface. However, such a port 3 has a function of distributing the billet 9 to each port hole 8, 8. However, if a large amount of billet 9 flows into one of the portholes due to flow rate differences, manufacturing errors, etc.,
There is also a problem that the billet that should flow into the other porthole side is attracted, and a product of uniform quality cannot be obtained.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to prevent the occurrence of uneven thickness and the nonuniform flow velocity of the billet. Another object of the present invention is to provide a die for extruding a hollow product which is capable of producing a hollow extruded profile having a uniform quality.

[0007]

In order to achieve the above object, the present invention provides a hollow product extruding die which comprises a die and a port and which extrudes a plurality of extruded profiles at the same time.
A plurality of port holes for forming each hollow extruded shape in the port are formed on a circumference centered around the die hole for each die hole, and a spigot portion which is fitted to each other at a joint surface between the die and the port. Is formed around each of the die holes, and a plurality of independent recesses are formed on the surface of the port opposite to the die corresponding to each of the port holes.

[0008]

In the present invention, since the spigot portion of the die and the port is formed corresponding to each die hole of the die, the center of the side surface of the port and the outer peripheral portion of the port are joined to the die.
Therefore, the deformation of the port due to the pressing force of the billet is small, and the deformation of the mandrel and the nonuniform flow velocity of the billet can be prevented unless the port is deformed. Further, since the recessed portion of the port has a guide function for the billet flowing into each port hole, the billet 9 flowing into one port hole side does not attract the billet that should flow into the other port hole side.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a front view showing an embodiment of a hollow product extrusion die according to the present invention, and FIG. 2 is a sectional view of the die. It should be noted that, in the drawings, the same components as those of the conventional die shown in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof will be omitted. In these drawings, the die 2 has two die holes 6 (6A, 6A) having the same hole diameter.
B) is formed on the same straight line passing through the center 0 of the die 1 and equidistant from the center 0. A plurality of port holes 8 (8A, 8B), for example, three port holes 8 (8A, 8B) are provided for each die hole 6A, 6B in the port 3, respectively, on the same circumference centered on the die holes 6A, 6B. Is formed so as to penetrate. Circular spigot parts 11 and 12 centering on the die holes 6A and 6B are formed on the joining surfaces of the die 2 and the port 3, respectively. One of the fitting portions 11 has a fitting recess 11A having an appropriate depth formed on the die 2 side and the fitting recess 11A formed on the port 3 side.
And a fitting protrusion 11B that fits in the. The other spigot portion 12 is similarly composed of a fitting recess 12A having an appropriate depth formed on the die 2 side and a fitting projection 12B formed on the port 3 side and fitted into the fitting recess 12A. ing. On the surface of the port 3 opposite to the die 2 side, circular recesses 13 and 14 having the same hole diameters as the outer diameters of the port holes 8A and 8B are centered around the die holes 6A and 6B, respectively. Has been formed. Other configurations are similar to those of the conventional structure shown in FIGS. 3 and 4.

Thus, in the hollow product extruding die having such a structure, since the spigot portions 11 and 12 are formed around the die holes 6A and 6B, respectively, uneven thickness occurs and the flow velocity of the billet 9 is increased. Can be prevented from becoming non-uniform. That is, since the die 2 and the port 3 are joined not only to the outer peripheral portion but also to the central portion by the spigot portions 11 and 12, even if the pressurizing force of the billet 9 is applied during the extrusion molding, the central portion of the port 3 is bonded to the die. There is no risk of deformation to the 2 side or inclination of the mandrel 7, and the facing gap between the die bearing surface 2a of the bearing portion 5 and the mandrel bearing surface 3a can be kept constant over the entire circumference. Therefore, if the hollow extruded shape member is not uneven in thickness and the facing gap is constant over the entire circumference of the bearing portion 5, there is almost no difference in the flow velocity of the billet 9 flowing into the die hole 6, and the pressure difference of the billet 9 causes. The inclination of the mandrel 7 can also be prevented. further,
The recesses 13 and 14 formed in the port 3 flow into one of the port holes, for example, 8A side, when the billet 9 enters the recesses 13 and 14 when the billet 9 flows into each of the port holes 8A and 8B. Even if the flow velocity of the billet 9 is faster than the flow velocity of the billet 9 flowing into the other port hole 8B, the billet 9 is rarely attracted, the amount of the billet 9 flowing into the other port hole 8B is reduced, or the flow velocity is decreased. Can be prevented. Therefore, it is possible to manufacture hollow extruded profiles having substantially the same quality.

In the above embodiment, the case where two hollow extruded shapes are extruded at the same time has been described. However, the present invention is not limited to this, and is directly applied to a die for molding two or more hollow extruded shapes. Of course, you can do that. In the above embodiment, the fitting recesses 11A and 12A are provided on the die 2 side.
Although the fitting protrusions 11B and 12B are formed on the port 3 side, the reverse may be applied.

[0012]

As described above, according to the hollow product extruding die according to the present invention, the spigot portion is formed in the die and the port corresponding to each die hole, and at the side opposite to the die side surface of the port. Since recesses are formed on the surface corresponding to each port hole, it is possible to reliably prevent the port from being deformed by the pressure of the billet during extrusion, the mandrel tilting, and the nonuniform flow rate of the billet. The product quality can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a die for hollow product extrusion according to the present invention.

FIG. 2 is a cross-sectional view of the die.

FIG. 3 is a front view showing a conventional example of a hollow product extrusion die.

FIG. 4 is a sectional view of the die.

[Explanation of symbols]

 1 Die 2 Die 3 Port 4 Hollow Extruded Profile 5 Bearing 6 Die Hole 7 Mandrel 8 Port Hole 9 Billet 11 Inlay Part 12 Inlay Part 13 Recess 14 Recess

Claims (1)

[Claims] 1. A die for extruding a hollow product, comprising a die and a port, wherein a plurality of extruded profiles are simultaneously extruded and molded, and a plurality of port holes for forming each hollow extruded profile at the port are provided for each die hole. Is formed on the circumference centered around the die hole, and spigot parts that are fitted to each other at the joining surface of the die and the port are formed around the die holes, respectively, and opposite to the die of the port. A hollow product extrusion die, characterized in that a plurality of independent recesses are formed on the side surface corresponding to the respective port holes.