JPH0794050B2 - Indirect extrusion equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of an indirect extrusion device that performs extrusion molding by relatively pushing a die or a combination of a die and a die holder into a container liner.

[Prior art and its problems]

An indirect extrusion device performs extrusion molding by inserting a billet into a container liner and then relatively pushing a die or a combination of a die and a die holder attached to the tip of a hollow stem into the container liner. Is.
In order to push the die or the combination of the die and the die holder into the container liner, the die side may be fixed and the container liner side may be moved, or the container liner side may be fixed and the die side may be moved.

In such an indirect extrusion device, in order to push or pull the die or a combination of the die and the die holder into the container liner, the outer diameter of the die or the die holder is made slightly smaller than the inner diameter of the container liner, and the space between them is reduced. Need to have clearance. However, due to this clearance, during extrusion, the extruded material remains as a shell on the inner surface of the container liner, and when the die or die holder is pulled out from the container liner after extrusion, the shell and die or die holder There is a problem that a very large force (container opening pressure) is required due to friction. In addition, when the die or die holder is pulled out, the shell on the inner surface of the container liner is peeled off unevenly on the back surface of the die or die holder, so that the residue causes entrapment or blistering in the extruded product during the next extrusion, resulting in product quality. There is also the problem of aggravating.

[Means for solving problems and their effects]

In order to solve the above-mentioned problems of the prior art, the present invention relatively pushes a die or a combination of a die and a die holder attached to the tip of a hollow stem into a container liner in which a billet is inserted. In an indirect extrusion device that performs extrusion molding, a tapered surface is formed on the outer circumference of the die or die holder, the diameter of which decreases toward the front, and a die nose ring whose front surface abuts the billet is tapered on the outer circumference of the tapered surface. When fitted, and when extrusion pressure is applied to the front surface of the die nose ring, the outer diameter of the die nose ring increases due to the sliding of the taper fitting portion, the clearance with the container liner becomes smaller, and the extrusion pressure is released. And the outer diameter of the die nose ring is reduced due to the sliding of the taper fitting part and the clear run with the container liner. It is characterized in that you have to increase.

According to the above configuration, when the die or the die holder is pulled out from the container liner, the outer diameter of the die nose ring provided on the outer periphery of the die is smaller than that at the time of extrusion, so that the pulling can be performed with a small force and the shell does not peel.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2 show an embodiment of the present invention.
FIG. 1 shows a state before starting extrusion, and FIG. 2 shows a state during extrusion. In the figure, 11 is a container liner, 12 is a bottom plate, and 13 is a billet inserted into the container liner 11. Further, 14 is a hollow stem, 15 is a die holder screwed to its front end, 16 is a die held by the die holder 15, and 17 is a die.
It is a backer interposed between 16 and stem 14.

The feature of this indirect extrusion device is that a taper surface 18 is formed on the outer circumference of the die holder 15 so that the diameter becomes smaller toward the front, and a die nose ring 19 whose front surface abuts the billet 13 is tapered on the outer circumference of the taper surface 18. It is a point that is combined. The outer diameter of the front end of the dynos ring 19 is smaller than the inner diameter of the container liner 11 as shown in FIG.
There is a clearance of 20 between the two. The die nose ring 19 and the die holder 15 are connected by a snap ring 21 that straddles the flange portions of both. Snap ring
As shown in FIG. 3, reference numeral 21 has a concave cross section, and has a structure in which a cut 22 is formed at one position so that the outer diameter can be enlarged or reduced.

As shown in Fig. 1, the die nose ring is in the state before extrusion.
The front surface of the die 19 projects slightly ahead of the front surfaces of the die 16 and the die holder 15, and there is a gap 22 between the rear surface of the die nose ring 19 and the die holder 15. From this state, for example, when the container liner 11 is moved to perform extrusion, the extruded product 23 formed by the die 16 is extruded through the hollow stem 14 as shown in FIG. In this state, a large extrusion pressure is applied to the front surface of the die nose ring 19, so that the die nose ring 19 is attached to the tapered surface 18 of the die holder 15.
Sliding up and retracting, the outer diameter expands. Therefore, the clearance 20 with the inner surface of the container liner 11 becomes extremely small, and the shell (not shown) remaining on the inner surface of the container liner 11 is shown.
Becomes thinner.

Next, when one extrusion is completed and the container liner 11 is returned to its original position (the die 16 side is pulled out from the container liner 11), the extrusion pressure applied to the front surface of the die nose ring 19 is released, so The elastic contraction force of the die slides forward on the tapered surface 18 of the die holder 15 to reduce the outer diameter, resulting in the state shown in FIG. Therefore, the dyno's ring 19 and the inner surface of the container liner 11 are only in slight contact with each other, and the force for returning the container liner 11 to its original state (container opening pressure) may be extremely small. Further, the die nose ring 19 does not peel off the shell on the inner surface of the container liner 11, and the next time extrusion is not adversely affected by the scraped dust.

Table 1 shows the comparison results when the aluminum alloy was extruded by the apparatus of the above-mentioned example and the conventional apparatus.

In the above embodiment, the die nose ring is attached to the outer periphery of the die holder. However, when the die 16 is directly attached to the stem 14 as shown in FIG. 4 without using the die holder, the outer periphery of the die 16 is tapered. The surface 18 may be formed, and the die nose ring 1 may be taper-fitted on the outer periphery thereof.

〔The invention's effect〕

As described above, according to the present invention, since the die nose ring that expands in diameter when extrusion pressure is applied and contracts when released is attached to the outer periphery of the die or the die holder, the die from the container liner after extrusion is attached. Alternatively, the force for pulling out the die holder can be extremely small, and at the same time, the die or the die holder does not peel off the shell on the inner surface of the container liner, which is very effective in improving the quality of the product.

[Brief description of drawings]

1 and 2 are sectional views showing a state before extrusion and a state during extrusion of an indirect extrusion apparatus according to an embodiment of the present invention, FIG.
FIGS. (A) and (b) are a front view and a sectional view of a snap ring used in the same device, and FIG. 4 is a sectional view showing another embodiment of the present invention. 11-container liner, 12-bottom plate, 13-billet, 14-hollow stem, 15-die holder, 16-die, 17-backer,
18-tapered surface, 19-dinos ring, 20-clearance, 21-snap ring, 22-gap.

Claims (1)

[Claims] 1. An indirect extrusion apparatus for performing extrusion molding by relatively pressing a die or a combination of a die and a die holder attached to the tip of a hollow stem into a container liner into which a billet is inserted. Alternatively, a tapered surface is formed on the outer circumference of the die holder, the diameter of which decreases toward the front, and a die nose ring whose front surface abuts the billet is taper-fitted to the outer circumference of the tapered surface, and the die nose ring is extruded on the front surface. When pressure is applied, the outer diameter of the die nose ring expands due to the sliding of the taper fitting part, and the clearance with the container liner becomes smaller. The diameter is reduced to increase the clearance with the container liner. Indirect extrusion apparatus.