JPH04309430A - Die forming method of aluminum alloy - Google Patents

Abstract

PURPOSE:To allow the use of a forging blank material of a narrow width, thereby improving the yield of the material. CONSTITUTION:In the die forging method for an aluminum alloy which executes finish forging by finishing dies after roughing by roughers 2, 3; the impression width B of the roughers 2, 3 is set larger than the impression width C of the finishing dies and the width A of the forging blank material 10 to be supplied to the roughers 2, 3 is set smaller than the impression width C of the above- mentioned finishing dies. The end edge 10a of the forging blank material 10 having an easy tendency to the generation of overlaps is made to remain in the impression parts 12, 13 of the roughers 2, 3 and this end edge 10a is moved to forging flashes by finish forging.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hot die forging aluminum alloys, and more particularly to a method for die forging aluminum alloys that includes rough forging and finish forging.

0002

[Prior Art] Recently, the use of aluminum for automobile parts has been promoted from the perspective of reducing vehicle weight. For example, hot die forgings of aluminum alloy are used for automobile suspension parts such as upper arms, lower arms, and knuckles. It is being As is well known, hot die forging is a process in which a forged material heated to a predetermined temperature is compressed between an upper die and a lower die to form a predetermined shape. Because of its complex shape, it is difficult to finish it in one shot, so normally, after rough ground forging is performed using a rough ground die, finish forging is performed using a finishing die in one heat.

[0003] By the way, aluminum alloy materials have a property that the surface of the material that comes into contact with the mold has extremely poor ductility compared to steel materials, and for this reason, during forging, the material on the side surface of the material bends to one side. This makes it easy for so-called folding scratches to occur. Therefore, conventionally, as shown in Fig. 3, the width a of the forging material 1 is set larger than the impression width b of the rough ground mold 2 and the rough underground mold 3 that make up the rough ground mold. Edge portion 1a of material 1
was moved into the forging burr 4. The impression width b of the rough ground die is the same as the impression width c of the finishing die 5 and the upper and lower finishing die 6 that constitute the finishing die as shown in FIG. 4, and the semi-finished product obtained by rough ground forging is 7 is fitted and set into the impression part of the upper and lower finishing molds 6, and is finished into a predetermined size and shape by closing the upper and lower molds 5 and 6, and the forging burr 4 is removed by a trimming mold to form a finished product. .

[0004] For example, an upper arm, which is one of the suspension parts of an automobile, has a boss portion 8b at the apex of a substantially triangular main body portion 8a, as shown by reference numeral 8 in FIGS. 5 and 6. Therefore, when forming such an upper arm 8 by die forging, due to its planar expansion, using a simple rod-shaped material will inevitably increase the number of man-hours and reduce the yield. Therefore, as shown in FIG. 5, for example, a deformed bar 9 having a cross-sectional shape similar to the planar shape of the upper arm 8 is formed by hot extrusion, and this deformed bar 9 is cut along a cutting line L to a predetermined thickness. I am trying to obtain the forged material 10 of
(Refer to Japanese Patent No. 44), since this is not effective in preventing the occurrence of folding scratches, the width of the forged material 9a is set larger than the impression width b of the rough ground type.

[0005]

[Problems to be Solved by the Invention] However, according to the conventional die forging method for aluminum alloys, the width a of the forging material 1 is set larger than the impression width b of the rough ground die, so that the forging burr 4 Since a large amount of aluminum is generated, there is a problem in that not only is a significant decrease in material yield unavoidable, but also the production cost increases significantly due to the use of expensive aluminum materials.

The present invention was made to solve the above-mentioned conventional problems, and its purpose is to make it possible to use narrow forged materials, thereby contributing to improving the material yield. The object of the present invention is to provide a method for die forging alloys.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an aluminum alloy die forging method in which rough ground forging is performed using a rough ground die, and then finish forging is performed using a finishing die. is set larger than the impression width of the finishing die, and the width of the forging material provided to the rough ground die is set smaller than the impression width of the finishing die.

[0008]

[Operation] In the aluminum alloy die forging method configured as described above, the impression width B of the rough ground die is set larger than the impression width C of the finished die, so that bending and scratches do not occur in the impression part of the rough ground die. Even if an edge portion of the forged material that is easy to forge remains, the edge portion moves into the forging burr during finish forging using a finishing die later. Therefore, even if the width A of the forged material to be used in the rough die is set smaller than the impression width C of the finishing die, folding scratches will not remain in the product.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a rough forging process according to the present invention, and FIG. 2 shows a finish forging process. The forged product to be manufactured in this example is the upper arm 8 shown in FIG. ing. In addition, the above-mentioned Figures 3 and 4
The same parts as those shown in are given the same reference numerals. In this embodiment, the impression width B (FIG. 1) of the rough ground mold 1 and the rough underground mold 2 is set larger than the impression width C (FIG. 2) of the finishing mold, and the width of the forging material 10 to be provided to the rough ground mold. A is set smaller than the impression width C of the finishing die 5 and the upper and lower finishing die 6. That is, the impression width and forging material width of each die are set so that the relationship B>C>A holds.

During forging, as shown in FIG. 1, a forged material 10 is heated to a predetermined temperature (about 400° C.)
is set in the impression part 13 of the rough underground mold 3,
The forging material 10 is compressed by lowering the rough ground mold 2. Then, as the rough ground mold 2 descends, that is, the compression progresses, the forging material 10 is first stretched in the lateral direction (direction perpendicular to the forging direction), and its end edge 10a forms the impression of the upper and lower molds 2 and 3. The material reaches the inner surface of the rib 14a defining the sections 12, 13 and subsequently fills up into the recess 14b inside the rib 14a. Finally, the rough surface mold 2 is completely closed with respect to the rough underground mold 3, and in this mold closed state, a semi-finished product 17 having a forging burr 18 around it is formed. At this time, since the width A of the forging material 10 is set sufficiently smaller than the impression width B of the rough ground dies 2 and 3, the material at the edge portion 10a of the forging material 10 does not flow out to the forging burr 18, and therefore Edge portion 10 of forged material 10
Even if a folding flaw occurs in the portion corresponding to a, the folding flaw will remain on the edge of the semi-finished product 17.

Next, as shown in FIG. 2, the semi-finished product 17
is set on the impression part 16 of the upper and lower finishing die 6. At this time, since the impression width C of the finishing molds 5 and 6 is set smaller than the impression width B of the rough molds 2 and 3, the semi-finished product 17 is seated with its outer periphery on the mold surface around the impression part 16. It is set in the same state. Thereafter, when the semi-finished product 17 is compressed by lowering the finishing die 5, the outer circumference of the semi-finished product 17 is extended in the lateral direction, and a portion corresponding to the edge 10a of the forged material 10 is formed with a forging burr 18.
A product 19 having a predetermined size and shape is formed in the mold closed state. Therefore, in this finish forging, as described above, the end edge 10a of the forging material 10 is
Since the portion corresponding to the forging burr 18 moves into the forging burr 18, even if this portion is bent and scratched, it will not remain on the product 19. That is, even if a forged material 10 with a small width is used, folding scratches will not remain on the product 19, and its quality will be significantly improved. Note that this product 19 is completed after the forging burr 18 is removed using a separate trimming die (not shown).

[0013] Conventionally, as this type of forged material, a material cut from a continuous casting bar has been used instead of the forged material 10 cut from the extruded deformed bar. In this case, since casting defects unique to continuous casting exist in the surface layer of the continuously cast bar, conventionally, the width of the forged material must be set considerably larger than the width of the forged material 10 cut out from the extruded deformed bar. However, according to the die forging method of the present invention, casting defects are also discharged to the forging burr, so there is no need to set the width of the forging material to be particularly larger than the forging material 10 cut from the extruded deformed bar. Material yield will further improve.

Furthermore, the present invention does not limit the type of forging material, but instead of the forging material cut from the extruded deformed bar or the continuous casting bar,
A forged material cut from a rolled bar can also be used.

[0015]

[Effects of the Invention] As explained in detail above, according to the method for die forging aluminum alloy according to the present invention, even if the width of the forging material is set smaller than the impression width of the finishing die, folding and scratches will not occur. Since no more remains in the product, a significant improvement in material yield can be achieved, contributing to a reduction in production costs.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a rough ground forging process according to the present invention.

FIG. 2 is a sectional view showing a finish forging process according to the present invention.

FIG. 3 is a sectional view showing a conventional rough ground forging process.

FIG. 4 is a sectional view showing a conventional finish forging process.

FIG. 5 is a plan view of an upper arm, which is a product obtained by this die forging method.

6 is a side view of the upper arm shown in FIG. 5. FIG.

FIG. 7 is a perspective view showing an example of a forged material used in the present invention.

[Explanation of symbols]

2 Wasteland type 3. Wasteland underground type 5 Finishing mold 6　Finishing mold 10 Forged material 17 Semi-finished products 18 Forging burr 18´ forged burr 19 Products A Width of forged material B　Impression width of wasteland type C Finished impression width

Claims (1)

[Claims] 1. A die forging method for an aluminum alloy, in which rough ground forging is performed using a rough ground die, and then finishing forging is performed using a finishing die, in which the impression width of the rough ground die is set to be larger than the impression width of the finishing die, and A method for die forging an aluminum alloy, characterized in that the width of the forged material to be subjected to is set smaller than the impression width of the finishing die.