JPH0367765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a die for producing an extruded section having tall fins (including fin-like protrusions), and particularly to a die for producing an extruded section made of aluminum (including its alloys) or the like. It relates to dies used in the production of.

BACKGROUND TECHNOLOGY AND PROBLEMS TO BE SOLVED For example, as a heat dissipation plate for mounting semiconductor elements, as shown in FIG. 9, a large number of heat dissipation fins 62 are provided in parallel at predetermined intervals on a flat plate part 61. A heat sink 60 made of aluminum is widely used. Such a heat sink can be obtained by extruding an aluminum material, and a solid die as shown in FIG. 10 has conventionally been used as an extrusion die for this purpose. That is, a plurality of forming convex portions 102 having a narrow cross section and a narrow width in cross section protrude into the extrusion opening 101 of the die body 100 to form narrow holes 103 for forming the fins 62 between adjacent forming convex portions, and a remaining flat plate portion. A die in which a hole 104 was formed was used.

By the way, the amount of heat dissipated in the heat sink 60 is as follows:
Since the surface area of the heat dissipation fins 62 increases in proportion to the surface area, in order to improve the heat dissipation efficiency, it is required to provide the fins as high as possible in order to increase the surface area.

However, in the conventional solid die, in order to obtain an extruded shape having high fins, it is necessary to increase the length of the protrusion of the forming protrusion 102 into the extrusion opening 101, but if this is made longer, the protrusion length of the forming protrusion becomes longer. There was a drawback that the strength decreased and the fins 62 could not withstand the large pressure applied during extrusion processing, resulting in breakage, or the fins 62 were bent in a direction that widened the gap between adjacent molded convex parts, resulting in widening and narrowing of the wall thickness of the fins 62. . For this reason, with solid dies, it is difficult to manufacture a heat sink in which the ratio between the height of the fins, that is, the tongue ratio, is set to 1:5 or more.

In order to eliminate this drawback, an arch-shaped bridge is provided on the die body spanning all of the forming convex portions, and a protruding piece is provided from the bridge toward the forming convex portions to control the flow of the extruded material. Dies have been proposed to control and suppress the extrusion pressure applied to the molding convex portions, but these dies were not sufficient and also had drawbacks such as difficulty in forming bridges.

Such defects occur not only in heat dissipating plates having heat dissipating fins, but also in dies for producing other extruded shapes having fin-like protrusions.

This invention eliminates such drawbacks and allows
The purpose of the present invention is to provide an extrusion die that makes it possible to manufacture extruded sections having high fins with a ratio of 1:5 or higher, without causing defects such as breakage or poor wall thickness. It is something to do.

Means for Solving the Problems In order to achieve the above object, the present invention does not constitute the molding convex portion of the die for forming the fins of the extruded section as an integral part, but instead uses the die as a male die. The molding convex part is formed by combining a female mold with a member having a female mold on the base side and a male mold with a tip side of the molded convex part, which are apparently combined into one body. By doing so, it is intended to improve the strength against extrusion pressure.

That is, more specifically, it has a plurality of fins,
The distance between adjacent fins and the protruding height of the fins are 1:
A die for manufacturing an extruded shape having a size of 5 or more,
A die for manufacturing an extruded profile having high fins, in which a plurality of molding projections 3 protruding into an extrusion opening 12 form narrow holes 4 for forming high fins between adjacent molding projections. In this case, the molding convex portion 3 is formed integrally with the female die 1 and has a base protrusion 13 formed to protrude to a middle position of the extrusion opening 12, and a base protrusion 13 that protrudes in the extrusion direction and is connected to the base protrusion 13. By a die for manufacturing an extruded profile having high fins, characterized in that it is configured in combination with a mandrel part 23 of a male die 2 arranged so as to appear to protrude integrally at its tip. The above objectives were achieved.

Function The molding convex portion 3 is constructed by apparently combining the base protrusion 13 of the female die 1 and the mandrel portion 23 of the male die 2 into one body.
Compared to the case where the die female die 1 is constructed in one piece, the protrusion length of the entire molding convex portion can be increased while making the base protrusion 13 of the female die 1 shorter. Therefore, the strength against the extrusion pressure applied to the base protrusion 13 during extrusion is improved, so that the base protrusion 13 is prevented from breaking or bending.

Embodiment Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 8.

In this embodiment, as shown in FIG. 9, a large number of heat radiation fins 62 are provided in parallel at predetermined intervals on a flat plate part 61, and the ratio between the distance between adjacent fins and the height of the fins (tongue ratio) This figure shows an extrusion die for producing an aluminum heat sink 60 with a ratio of 1:5 or more.

In Figures 1 to 6, A is a die;
The die A is composed of a combination of a female die 1 and a male die 2.

As shown in FIG. 3, the female die 1 has a fitting recess 11 at one end, a recess 15 in the center of the fitting recess, and a penetrating extrusion opening in the center. It has 12. It has a plurality of base protrusions 13 that are formed to protrude in parallel at predetermined intervals up to the middle position of the extrusion opening 12. Here, the interval between adjacent base protrusions 13 corresponds to the thickness of each fin 62 of the heat sink 60.

On the other hand, the male die 2 has a protruding fitting part 22 formed on one end surface thereof with a stepped part 21 interposed therebetween. A plurality of mandrel parts 2 protruding in the extrusion direction are arranged transversely in the center of the fitting part 22.
3 are formed in parallel at predetermined intervals. This mandrel part is formed to have a rectangular cross section, and
A bearing portion 23a having a rectangular cross section is formed by bulging in the radial direction at the middle in the length direction. The width of each bearing portion 23a in the left-right direction is set to be the same as the width of the base protrusion 13 of the female die 1, and the adjacent bearing portions 23a, 23a
The interval is the interval between adjacent base projecting pieces 13, that is, the interval between heat sinks 60
This corresponds to the wall thickness of each fin 62. Further, in the male die 2, passage holes 24, 24 for extruded material are formed above and below with the mandrel portion 23 in between.

Therefore, the die A is connected to the fitting part 22 of the male die 2.
It is constructed by fitting and fixing into the fitting recess 11 of the female die 2. In this state,
As shown in FIGS. 1 and 2, the mandrel portion 23 of the male die 2 is positioned horizontally protruding above the base protrusion 13 of the female die 1, and as shown in an enlarged view in FIG. In addition, a notch 23b provided on the outer side of the lower end of the bearing portion 23a is disposed opposite to the stepped portion 14 provided at the upper end of the base projecting piece 13 with a slight distance therebetween. Such a base protrusion 13 of the female die 1 and the male die 2
Due to the combined arrangement with the mandrel part 23, the base projecting piece 13 and the mandrel part 23 are apparently integrated and protrude into the extrusion opening 12, thereby forming the molded convex part 3. being done. A narrow hole 4 for forming the fins 62 of the heat dissipation plate 60 is provided between the adjacent molded convex portions 3, 3.
is formed, while a flat plate part 6 is formed above the molded convex part 3.
A hole 5 for forming a hole 5 is formed therein.

In the extrusion process using the die A, the extruded material passes through the upper and lower passage holes 24 of the male die 2, and passes through the fin forming holes 4 between the adjacent molding convex portions 3, 3.
After flowing into the flat plate forming holes 5, it is extruded to the heat sink 60 through these holes. During such extrusion, extrusion pressure is applied to the base protrusion 13 of the female die 1, and the protrusion receives a bending moment in the extrusion direction or sideways, but the base protrusion 13
Since the projecting length is short, it has sufficient strength against this bending moment and does not break, and also suppresses lateral deflection and maintains a constant distance between adjacent molded convex parts. Therefore, the thickness of the fins 62 of the heat dissipating plate 60 does not deteriorate.

In the above embodiment, the base protrusion 13 of the female die 1 and the mandrel portion 23 of the male die 2 are
The bearing 23a of the mandrel part was assembled with its cutout part 23b facing the stepped part 14 of the base protrusion 13 with a slight gap between them, but as shown in FIG. 7 and FIG. The lower surface of the bearing portion 23a' of the mandrel portion 23' of the male die 2' may be placed in contact with the upper surface of the base protrusion 13' of the female die 1'.

Effects of the Invention According to the present invention, the molding convex portion is constructed by combining the base protrusion of the female die and the mandrel portion of the male die in an apparent manner as described above. Although the length of the base protrusion is shortened compared to the conventional die constructed, the protrusion length of the entire molding convex portion can be increased. Therefore, the strength of the base protrusion against the extrusion pressure during extrusion can be improved,
It is possible to manufacture high-quality extruded shapes with high fins such that the distance between the fins and the height of the fins is 1:5 or more, while preventing breakage and defects in wall thickness of the fins due to lateral deflection. It becomes possible.

[Brief explanation of drawings]

1 to 6 show one embodiment of the present invention, in which FIG. 1 is a front view of the die seen from the male die side, FIG. 2 is a cross-sectional view taken along the - line in FIG. The figure is a perspective view showing the state before the female mold and male mold are combined;
Fig. 4 is a cross-sectional view taken along the line - in Fig. 1 with some parts omitted, Fig. 5 is an enlarged cross-sectional view showing the vicinity of the molding convex part in Fig. 2, and Fig. 6 is a cross-sectional view of Fig. 2. - The line sectional view, FIGS. 7 and 8 show modified examples of the combination of the base projecting piece and the mandrel part, and FIG. 7 is a view corresponding to FIG. 2, with only the main parts enlarged. The sectional view shown in FIG. 8 is further enlarged sectional view, FIG. 9.
The figure is a sectional view of a heat sink as an example of an extruded shape manufactured by the die according to the present invention, and FIG. 10 is a front view for explaining the schematic structure of a conventional die. A...Dice, 1,1'...Female die, 12
...Extrusion opening, 13, 13'...Base protrusion, 2,
2'... Male die, 23, 23'... Mandrel portion, 3, 3'... Molding convex portion, 4... Fin forming hole, 60... Heat sink, 62... Fin.

Claims (1)

[Claims] 1 Having multiple fins, between adjacent fins
A die for producing an extruded shape material in which the protrusion height of the fins is 1:5 or more, and a plurality of molding protrusions 3 protruding into the extrusion opening 12 form high fins between adjacent molding protrusions. In the die for producing an extruded profile having high fins, the molding convex portion 3 is formed integrally with the die female mold 1, and the extrusion opening 12 is formed with a narrow hole portion 4 for extrusion.
The base protrusion 13 is formed to protrude to an intermediate position.
and a mandrel portion 23 of the male die 2 which protrudes in the extrusion direction and is arranged so as to appear to protrude integrally from the tip of the base protrusion. , dies for the production of extruded profiles with high fins.