JPS6350010Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an extrusion die for hollow materials whose purpose is to make the quality of the product as uniform as possible when extruding the hollow materials.

Conventionally, in order to homogenize hollow extruded products, it is known that one or more feeder plates are stacked on the rear end surface of a mandrel to divide the flow path of the material into multiple sections (Japanese Patent Publication No. 51-38320). ). When the flow path of the material is divided into multiple parts as in the above invention, the number of fused parts in the hollow extruded product increases according to the number of divisions, and the dispersion of the fused parts makes it more homogeneous. It is true that there is a problem in that the capacity of the extrusion press for billet material must be increased, and there is a significant restriction on the number of feeder plates.

However, this invention succeeded in suppressing the increase in extrusion pressure of the billet material as much as possible and homogenizing the hollow extruded product by providing a dividing piece protruding from the introduction part of the mandrel.

When feeder plates are superimposed behind the mandrel as in the known invention, the billet material is first divided into a plurality of pieces by the first feeder plate, and then divided into a plurality of pieces by the second feeder plate ( The billet material is further divided at the introduction part of the mandrel), and the material bends and flows during this time, creating considerable resistance, and the pushing force of the billet material correspondingly increases. It is divided by the number of introduction parts, and then divided by division pieces, and there is a part without division pieces (the gap between the division piece and the inner wall of the introduction part), so the pushing resistance is smaller than the number of divisions. becomes significantly smaller. Therefore, the pressure applied to the billet material was small, and the extruded product was made more homogeneous.

That is, to explain this invention with reference to an embodiment, a mandrel 2 that is inserted into one side of a die ring 1 is used.
, side fan-shaped introduction parts 3, 3a, 3b, 3c, 3
d are provided evenly and radially, and the divided pieces 5, 5 are inserted from the center shaft part 4 of the mandrel 2 to each introduction part.
a, 5b, 5c, and 5d are provided protrudingly. The rear end surfaces of the divided pieces 5, 5a, 5b, 5c, and 5d are provided a predetermined length l lower than the rear end surface 2a of the mandrel 2, and the free end surfaces of each divided piece 5, 5a, 5b, 5c, and 5d are A gap S is provided between the introduction parts 3, 3a, 3b, 3c, and 3d and the inner wall surface 2b, and the front end surface of each divided piece 5, 5a, 5b, 5c, and 5d is flush with the entire end surface of the mandrel 2. Atsushi, Dice Plate 6
It is in contact with the rear end surface of the divided projecting piece 7. The core portion 8 of the mandrel 2 is inserted into the center of the die hole 9 of the die plate 6 over a predetermined length to form a die.

In order to extrude a hollow material of aluminum (including aluminum alloy) using the die of the above embodiment, the billet material 10 in the container 11 is pressed with a predetermined pressure using a pressing plate (not shown).
The billet material 10 softens and flows from the front end side, is first divided as shown by the arrow 12 and enters the introduction section, and is then further divided by the dividing pieces 5, 5a, 5b, and 5c. The solid portions are not divided) and flow as shown by arrows 13 and 14 to form the desired hollow material 15. In the above, the billet material 10 is in a pressurized molten state and flows as shown by arrows 12, 13, and 14.
In order to create a flow divide by the dividing pieces, the welded parts of the cross section of the product are equally divided into twice the number of introduction parts, as shown in Figure 3. Therefore, even if the properties of the welded part a and the other part b are slightly different, it has been recognized that the product material is almost constant because the part is divided into many parts and evenly distributed.

The dividing piece in the above embodiment divides each introduction part into 1/2 at approximately the center, and provides a slight gap facing the inner wall surface of the introduction part, and the rear end face of the divided piece is slightly smaller than the rear end face of the mandrel. However, there are no particular restrictions on the gap or the height from the end face of the mandrel, and there are no limitations on the number, shape, or size of the divided pieces.

That is, according to this invention, since the dividing piece is provided protrudingly from the introduction part of the mandrel, the number of welds generated in the cross section of the product is increased and the welds are evenly distributed, which has the effect of making the material of the product uniform. In addition, despite increasing the number of parts into which the flow of material is divided, the increase in extrusion pressure is suppressed as much as possible, and there is an effect that extrusion operation can be carried out without much difference from the extrusion pressure using conventional dies.

[Brief explanation of drawings]

FIG. 1 is a side view of the die of this invention, FIG. 2 is a sectional view, and FIG. 3 is an enlarged sectional view of the product. 1... Dairing, 2... Mandrel, 3,3
a, 3b, 3c, 3d...Introduction, 5, 5a, 5
b, 5c, 5d...Divided piece, 6...Dice plate, 7...Divided projecting piece, 8...Core part, 10...
Billet wood.

Claims (1)

[Claims for Utility Model Registration] 1. A mandrel in which a plurality of introducing portions are provided radially from the center toward the periphery and a die plate having a die hole, the core of the mandrel being in the center of the die hole. An extrusion die made of a hollow material, which is in contact with each other so as to face each other, and has a dividing piece protruding from the center toward the periphery of the introducing portion. 2. The extrusion die for hollow material according to claim 1, wherein the number of divided pieces is the same as the number of introduction parts, and the die is installed at a position dividing each introduction part into two. 3. The die for extruding a hollow material according to claim 1, wherein the dividing piece has a rear end face lower than the rear end face of the mandrel toward the front side, and the front end is brought into contact with a dividing protruding piece of the die plate. 4. The extrusion die for hollow material according to claim 1, wherein the protruding position of the divided piece is such that a predetermined gap is provided between the free end of the divided piece and the inner wall of the introduction part. 5. The die for extruding a hollow material according to claim 3, wherein the divided projecting pieces of the die plate have a width such that they abut over a predetermined width on the free end side of the divided pieces of the mandrel.