JP2625167B2 - Manufacturing method of forged products - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a method of manufacturing a forged product by forging a blank material forged into a predetermined shape.

(Prior art) In general, Al-Si-Cu alloys, Al-Si-Cu-Mg alloys, etc.
Since it has good forgeability and excellent strength and toughness can be obtained by heat treatment, it has been widely used as a forging alloy for rocker arms and the like as engine parts for vehicles such as automobiles. However, at present, when the output of the engine is being increased, the rocker arm and the like are exposed to severe conditions during operation, so that the mechanical properties such as the strength and the toughness are further required to be improved. Therefore, in order to satisfy this requirement, for example, as disclosed in JP-A-62-187539, a blank material is forged with an Al-Si-Cu alloy or the like as described above, and then the blank material is forged. There is known a method of improving the mechanical properties by performing the method.

(Problems to be Solved by the Invention) By the way, the blank material subjected to forging as described above is cut and separated from the weir for injecting the molten metal into the mold after forging. So, blank material a
In the blank material body b, the weir cutting residue c protrudes and remains. When the blank material a having such a weir cutting residue c is set in the die d of the forging device and forged, the blank material a is compressed by the die d and the punch e and plastically deformed. As shown in FIG. 3 (b), there is a problem that a crack-like groove f is generated in a portion of the forged product g corresponding to the outer periphery of the remaining weir cut c due to the flow of the blank material a caused by the deformation. there were. Such a groove f generation phenomenon is due to the fact that the weir cutting residue c protrudes at right angles to the end face of the blank material body b to form a step. This is due to the fact that it is faster to approach.

The present invention has been made in view of such a point, and an object of the present invention is to appropriately arrange a blank material in a forging device, thereby forming a crack-shaped portion at a portion corresponding to the outer periphery of the remaining weir cut of the blank material. An object of the present invention is to obtain a forged product without grooves.

(Means for Solving the Problems) In order to achieve the above object, a solution of the present invention is a method for manufacturing a forged product by forging a blank material forged into a predetermined shape. Forging a blank material having a weir cutting residue projecting to the side. Next, after supporting the blank material on a die of a forging device so that the remaining weir cut residue is positioned on the mating surface with the punch, the blank is compressed and plastically deformed by the die and the punch to obtain a forged product. To do.

(Operation) According to the above configuration, in the method of the present invention, in the forging, the blank material is supported on the die such that the remaining weir cut portion protruding from the blank material body is positioned on the mating surface with the punch of the forging device. Therefore, it is substantially the same as forging a blank material having no protruding portion, that is, a blank material body having a flat flat end face, and thus, the projection of meat caused by a step at the blank material body end face. There is no difference in timing, so that crack-like grooves are reliably prevented from being formed in a portion corresponding to the outer periphery of the remaining portion of the weir.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1A and 1B show a case where a rocker arm A as an engine part for a vehicle such as an automobile is forged by a forged product manufacturing method according to an embodiment of the present invention. To explain the manufacturing procedure, first, a blank material B having a predetermined shape is forged by a forging device (not shown). The blank body b ₁ end surface of the blank B, as shown in detail enlarged FIG. 2 (a), after forging, the weir cutting remainder b ₂ which is weir and cut separation of injecting the molten metal into the mold It is formed to protrude.

Next, the blank material B forged as described above is carried into the forging device 1, and as a feature of the present invention, the weir cutting residue b ₂ is placed above the die 2 on the die 2 as a lower die of the forging device 1. Is supported so as to be positioned on the mating surface with the punch 5 as an upper die which is arranged to be able to move up and down. Specifically, a support pin 4 urged upward by a spring force of a coil spring 3 and having a tip protruding into an impression is disposed on the die 2 so as to be able to protrude and retract. The above-mentioned blank part B is supported at three points without shaking.

Thereafter, as shown in FIG. 1 (b), the punch 5 is lowered, and as shown in an enlarged detail in FIG. 2 (b), the blank material B is compressed by the die 2 and the punch 5 to form a plastic. The rocker arm A is obtained by the deformation. At this time, the support pin 4 is immersed by the lowering operation of the punch 5 against the spring force of the coil spring 3, the base end of the support pin 4 is brought into contact with the cylindrical member 6, and the tip end is flush with the die 2 shape portion. It is made to be located in.

Thus, in this embodiment, when forging, the blank B, allowed to support on the die 2 as dam cutting remainder b ₂ of the blank body b ₁ is positioned on the mating surface of the punch 5 forging device 1 since, in effect, be the same thing as the dam cutting remainder b ₂ without blank B, i.e. the blank body b ₁ end surface to forge a flat blank B, thus in the blank body b ₁ end face without a difference occurs in the corbel timing of meat due to the step, thereby cracking shaped grooves are reliably prevented from occurring in the portion corresponding to the outer periphery of the weir cutting remainder b _2.

Thereafter, after the punch 5 is raised, the rocker arm A is carried out of the forging apparatus 1 and is subjected to a predetermined heat treatment condition.
Was subjected to T ₆ treatment, the product was removed trim type, not shown flash (burr) a ₁ formed during the forging.

Thereafter, the rocker arm A is removed the flash a ₁
Into the shot peening step to clean the surface and finish the forging operation.

In the above embodiment, the case where the forged product is the rocker arm A as an engine part for a vehicle such as an automobile has been described, but it is needless to say that the present invention is not limited to this.

(Effects of the Invention) As described above, according to the method of the present invention, a blank material having a weir cutting residue projecting from a blank material body is forged, and then the blank material is cut on a die of a forging device by the weir cutting. After being supported so that the remaining part is located on the mating surface with the punch, it is compressed and plastically deformed by the die and the punch. This makes it possible to reliably prevent crack-like grooves from being generated at a portion corresponding to the outer periphery of the remaining weir cut residue.

[Brief description of the drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 (a) and (b)
2 is a longitudinal sectional view showing a forging device before and after forging, respectively, and FIGS. 2 (a) and 2 (b) are enlarged views of main parts of FIGS. 1 (a) and 1 (b), respectively. FIG. 3 (a) and (b)
FIGS. 2 (a) and 2 (b) are diagrams respectively showing conventional examples. 1 ...... forging device, 2 ...... die, 5 ...... punch, A ...... rocker arm (forging), B ...... blank, b ₁ ...... blank body, b ₂ ...... dam cutting balance.

Claims (1)

(57) [Claims] 1. A method of manufacturing a forged product by forging a blank material cast into a predetermined shape, comprising forging a blank material having a weir cut remainder projecting from a blank material body, and then forming the blank material. After supporting the weir cutting residue on the die of the forging device so as to be positioned on the mating surface with the punch, the forged product is obtained by compressing and plastically deforming the die and the punch. Manufacturing method of forged products.