JP2758029B2 - Aluminum part manufacturing method and forging die used therefor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an aluminum part by casting an aluminum material made of aluminum or an aluminum alloy obtained by continuous casting, and a forging die used for the method. .

(Prior art) The forging method has been widely adopted as a method for manufacturing aluminum parts, particularly aluminum parts requiring strength and reliability, because the quality inside the product is good and the mechanical properties are also improved. ing.

However, since the forging method has a smaller degree of freedom than the casting method, when manufacturing aluminum parts having a complicated shape such as an upper arm, the yield of the material is low, and the material is wasted. Easy to occur.

Therefore, recently, as shown in FIG. 3 of JP-A-59-206133, in particular, as shown in FIG. 3, after continuously casting an aluminum material having a uniform sectional shape similar to the sectional shape of an aluminum component, There has been proposed a method for manufacturing a forged component in which a material is cut to a predetermined thickness to obtain a forging material, and then the forging material is set in a forging die and forged. In this case, the forging is continuously cast such that the horizontal cross-sectional area of the forging material is slightly smaller than the product projected area of the aluminum part, and is cut so that the vertical cross-sectional area is larger than the height of the aluminum product. Materials are used.

(Problems to be solved by the invention) However, when an aluminum material made of aluminum or an aluminum alloy is cast by a continuous casting method,
In the casting process, a surface defect layer consisting of hot water or a reverse segregation layer is formed on the surface of the aluminum material. As shown in FIG. 5, when the aluminum material b having the surface defect layer a is set on the bottom of the product shape engraved portion e of the lower die d of the forging die c, forging is performed, as shown in FIG. In addition, the surface defect layer a of the aluminum material b remains in the product shape engraved portions e and g of the lower mold d and the upper mold f, and as a result, the surface defect layer a remains on the surface of the aluminum component, resulting in quality deterioration. There is a problem.

As a countermeasure, forging may be considered after shaving off the surface defect layer a of the aluminum material b obtained by the continuous casting method. However, as in the case of the aluminum material obtained by the continuous casting method, it is similar to an aluminum component. In the case of a material having a complicated cross-sectional shape or the like, it is extremely difficult to remove the surface defect layer a from the aluminum material b. For this reason, there has been a problem in that an aluminum component obtained by forging an aluminum material obtained by continuous casting has a surface defect layer composed of hot water lines and a reverse segregation layer.

In view of the above, the present invention is a method for manufacturing an aluminum component by forging an aluminum material obtained by continuous casting, but does not leave a surface defect layer made of hot water and a reverse segregation layer in the obtained aluminum component. And a forging die used for the method.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a forging method in which a surface defect layer of a forging material is positioned outside a product shape engraving part of a forging die, and a surface defect layer is formed. The layer is formed as burrs and protrudes into the periphery of the forging material.

Specifically, a solution taken by the invention of claim 1 is to cut a continuously cast aluminum material to a predetermined thickness to obtain a forging material having a surface defect layer on the surface excluding the cut surface. A material placing step for placing the material for forging on the upper periphery of the product shape engraving portion of the lower mold, and a product shape engraving on the mating surface of the upper mold and the lower mold. After preparing a forging die having a burr accommodating portion for accommodating a burr including the surface defect layer, which is generated around the forging material at the time of forging outside the portion, the lower mold is provided with a material mounting step portion. The forging material is placed so that the cut surface of the forging material is positioned in the vertical direction, and thereafter, the forging material is forged by the upper mold and the lower mold, and includes the surface defect layer. An aluminum part is obtained while the burr is housed in the burr housing part. It is an configuration.

According to a second aspect of the present invention, the forging die used in the manufacturing method of the first aspect includes an upper die and a lower die, and a product projection of an aluminum part is formed on an upper peripheral edge of a product shape engraving portion of the lower die. In addition to a material mounting step for mounting a forging material cast in a cross-sectional shape slightly larger than the cross-sectional shape obtained by adding a surface defect layer to the shape, the product shape at the mating surface of the upper and lower dies A burr accommodating portion for accommodating a burr generated around the forging material at the time of forging is provided outside the engraving portion.

(Function) According to the first and second aspects of the present invention, the forging material is forged in a state where the forging material is placed on the material placing step provided on the upper peripheral edge of the lower product engraving portion. To do
Since the surface defect layer formed around the forging material is forged in a state of being located outside the product engraving portion, the surface defect layer protrudes outside the product shape engraving portion as burrs after forging.

In particular, in the invention of claim 1, after the forging material is placed on the material placing step of the lower die such that the cut surface of the forging material is positioned in the vertical direction, the forging material is placed on the upper mold. Since the burrs including the surface defect layer are forged by the lower mold, the burrs containing the surface defect layer are reliably accommodated in the burrs.

(Example) Hereinafter, as one example of the present invention, a method of manufacturing an aluminum alloy upper arm which is an aluminum component will be described with reference to the drawings.

First, a JIS-A6061 aluminum alloy was prepared as a material, and this was continuously cast by a well-known continuous casting method to form a first alloy.
An aluminum material 1 as shown in the figure is obtained. When the aluminum material 1 is obtained in this way, as shown in FIG.
On its surface, a surface defect layer 2 consisting of a hot water line 2a or a reverse segregation layer 2b is formed to a thickness of about 1 mm. Thereafter, the aluminum material 1 is cut into a predetermined thickness to obtain a forging material.

On the other hand, as shown in FIG.
And a lower die 4. The lower die 4 has a material placing step 6, which is a cutout step on which the forging material 5 is placed, on the upper peripheral edge of the product shape engraving part 4 a. And a burr accommodating portion 7, which accommodates a burr generated around the forging material 5 at the time of forging, outside of the product shape engraving portions 3a, 4a on the mating surface of the lower mold 4.
Prepare one with 7.

Next, as shown in FIG. 2, the forging material 5 obtained as described above is heated to about 450 ° C., and then placed on the material placing step 6 of the lower die 4. In this case, assuming that the forging material 5 is placed on the material placing step 6, it is assumed that the horizontal sectional shape of the forging material 5 corresponds to the product projection shape of the aluminum component to be obtained. The aluminum material 1 is continuously cast so as to be slightly larger than the cross-sectional shape including the thickness and slightly smaller than the outer shape of the material mounting step portion 6. When the casting material 5 that is slightly smaller than the outer shape of the material placing step 6 is set in the material placing step 6, positioning of the forging material 5 is facilitated.

Next, after setting the upper die 4 on the forging material 5, it is hot forged by a well-known forging method.

As described above, the forging material 5 is cast into a cross-sectional shape that is slightly larger than the cross-sectional shape obtained by adding the surface defect layer 2 to the product projected shape of the aluminum part, and the product shape engraving portion 4a is formed.
Forging is performed in a state where the material is placed on the material placing step 6 formed on the upper peripheral edge of the forged product 8 as shown in FIG. Step 6
Is formed, and the surface defect layer 2 formed on the surface of the forging material 5 protrudes as burrs 9 into the burrs 7,7.

Thereafter, the forging die is opened, the forged product 8 forged into the shape shown in FIG. 4 is taken out from the forging die, and the protruding portion 8a and the burr 9 formed around the forged product 8 are removed by a trimming die. And obtain aluminum parts.

By performing forging as described above, the surface defect layer 2 of the forging material 5 protrudes as burrs 9 into the burrs 7, 7, and the protruding burrs 9 are removed by trimming. The surface defect layer 2 does not remain in the aluminum component to be obtained.

(Effects of the Invention) As described above, according to the first and second aspects of the invention, the forging material is placed on the material placing step provided on the upper periphery of the lower product shape engraving portion. Since the forging is performed in this state, the surface defect layer formed of the hot water or the reverse segregation layer formed around the forging material protrudes as burrs around the forged product. For this reason, although the aluminum material having the surface defect layer obtained by continuous casting is forged, the surface defect layer does not remain in the obtained aluminum component.

In particular, according to the first aspect of the present invention, after the forging material is placed on the material placing step of the lower die such that the cut surface of the forging material is positioned in the vertical direction, the forging material is placed on the upper die. Since the burrs including the surface defect layer are surely accommodated in the burrs accommodating portion due to the forging with the die and the lower mold, the surface defect layer does not remain in the obtained aluminum component.

[Brief description of the drawings]

1 to 4 show a method of manufacturing an aluminum part according to one embodiment of the present invention. FIG. 1 is a sectional perspective view of an aluminum material obtained by continuous casting, and FIG. FIG. 3 is a cross-sectional view of a forged material obtained by forging, FIG. 3 is a bottom view of a forged product obtained by forging, FIG. 5 and FIG. FIG. 5 is a sectional view showing a state in which the forging material is set in a forging die, and FIG. 6 is a sectional view showing a state in which the forging material is forged. DESCRIPTION OF SYMBOLS 1 ... Aluminum material 2 ... Surface defect layer 3 ... Upper mold 4 ... Lower mold 3a, 4a ... Product shape engraving part 5 ... Forging material 6 ... Material mounting step 8 ... Forged product 9 ... Bali

Claims (2)

(57) [Claims] 1. A continuously forged aluminum material is cut to a predetermined thickness to obtain a forging material having a surface defect layer on a surface excluding a cut surface, while an upper die and a lower die are provided. A forging material is provided on the upper periphery of the product shape engraving part, and the forging material is placed on the outer periphery of the product shape engraving part at the mating surface of the upper and lower dies. After preparing a forging die having a burr accommodating portion that surrounds and contains a burr including the surface defect layer, a cut surface of the forging material is provided on the material placing step of the lower mold. Are placed so that they are positioned in the vertical direction. Thereafter, the material for forging is forged by the upper mold and the lower mold, and the burr including the surface defect layer is housed in the burr housing part. Aluminum characterized by obtaining aluminum parts by Method of manufacturing the goods. 2. A sectional shape comprising an upper mold and a lower mold, and having a cross-sectional shape slightly larger than a cross-sectional shape obtained by adding a surface defect layer to a product projected shape of an aluminum part at an upper peripheral edge of a product shape engraved portion of the lower mold. With a material mounting step for mounting the cast forging material, burr generated around the forging material at the time of forging is formed on the outside of the product shape engraving part at the mating surface of the upper mold and the lower mold. A forging die comprising a burr receiving part for receiving.