JPH0263628A - Manufacture of forged part - Google Patents

Abstract

PURPOSE:To prevent the generation of a crack-like groove of a product by supporting a gate cut remaining part of a blank stock so as to be positioned on the mating face of a forging die and a punch, and subsequently, compressing the blank stock by the die and the punch and bringing it to plastic deformation. CONSTITUTION:A blank stock B is cast and formed in advance to a prescribed shape having a gate cut remaining part protruded to its body. Subsequently, the blank stock B is brought to three-point support together with a supporting pin 4 so that a gate cut remaining part b2 of the blank stock B is positioned on the mating face to a punch 5 on the lower die 2. Thereafter, the blank stock B is compressed by the die 2 and the punch 5, and brought to plastic deformation. At the time of forging, since the gate cut remaining part b2 is set to the mating face of the die 2 and the punch 5, a protrusion timing difference of a metal caused by a step difference on the end face of the blank stock B body can be eliminated, by which it can be prevented surely that a crack-like groove is generated in the part corresponding to the outside periphery of the gate cut remaining part b2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a method for manufacturing a forged product by forging a blank material cast into a predetermined shape.

(Prior art) In general, Aj) -8i -Cu-based alloys and AlAl1-
8iCu-based alloys have good castability and can obtain excellent strength and toughness through heat treatment, so they have been widely used as alloys for casting rocker arms and other engine parts for automobiles and other vehicles. ing. However, in today's world where there is a demand for higher engine output, the rocker arms and the like are exposed to harsh conditions during operation, so there is a further demand for improved mechanical properties such as the strength and toughness. Therefore, in order to meet this demand, for example, as disclosed in Japanese Patent Application Laid-Open No. 187539/1982,
By casting a blank material using Aρ-8t-Cu alloy as described above, and then forging this blank material,
Methods for improving mechanical properties are known.

(Problem to be solved by the invention) By the way, the blank material used for forging as described above is
After casting, since the weir is cut and separated from the weir for injecting the molten metal into the mold, the weir cut residue C remains protruding from the blank body of the blank material a, as shown in FIG. 3(a). Then, when the blank material a having such a weir cut residue C is set in the die d of the forging device and forged, the blank material a1. Then, the blank material a is compressed and plastically deformed by the die d and the punch e, and due to the flow of the flesh of the blank material a accompanying this plastic deformation, as shown in FIG. There was a problem in that a crack-like groove f was generated at a portion corresponding to the outer periphery of C. This type of groove f generation phenomenon is due to the above-mentioned weir cutting residue C protruding at right angles to the end face of the blank material body, forming a step, and rather than eliminating this step during forging, the surrounding area This is due to the fact that the meat pushes out faster.

The present invention has been made in view of the above points, and its purpose is to properly place the blank material in a forging device, thereby creating a crack-like shape in a portion of the blank material corresponding to the outer periphery of the weir-cut portion. The objective is to obtain a forged product that does not generate grooves.

(Means for Solving the Problem) In order to achieve the above object, the solving means of the present invention provides a method for manufacturing a forged product by forging a blank material cast into a predetermined shape. A blank material with a protruding weir cut remainder is cast. Next, this blank material is supported on a die of a forging device so that the remaining part of the weir cut is located on the mating surface with the punch, and then the forged product is compressed and plastically deformed between the die and punch. Try to get it.

(Function) With the above configuration, in the method of the present invention, during forging, the blank material is supported on the die so that the weir cut portion protruding from the blank material body is located on the mating surface with the punch of the forging device. Therefore, it is essentially the same as forging a blank material without the above-mentioned protrusion, that is, a blank material with a flat end surface of the main body of the blank material, and therefore, the protrusion of the flesh due to the step on the end surface of the main body of the blank material. There is no difference in timing, and as a result, it is possible to reliably prevent a crack-like groove from forming in a portion corresponding to the outer periphery of the weir cut remaining portion.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIGS. 1(a) and 1('b) show a case in which 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 cast using a casting device (not shown). As shown in enlarged detail in FIG. 2(a), on the end face of the blank wood body b1 of this blank material B, a weir cut portion b2, which was cut and separated from the weir for injecting molten metal into the mold after casting, protrudes. It is formed.

Next, the blank material B cast as described above is carried into the forging device 1, and as a feature of the present invention, the weir cut remaining portion b2 is placed above the die 2 on the die 2 as the lower die of the forging device 1. It is supported so as to be positioned on a mating surface with a punch 5 as an upper mold which is arranged to be movable up and down. Specifically, a support pin 4 whose tip is urged upwardly by the spring force of a coil spring 3 and protrudes into the impression is retractably disposed on the die 2, and the support pin 4 and the die 2 The blank material B is supported at three points to prevent it from wobbling.

Thereafter, as shown in FIG. 1(b), the punch 5 is lowered, and as shown in enlarged detail in FIG. 2(b), the blank material B is compressed by the die 2 and the punch 5 to make it plastic. By deforming it, Lotsukaam A is obtained. At this time, the support pin 4 is moved to the coil spring 3 by the downward movement of the punch 5.
The proximal end is inserted into the cylinder member 6 against the spring force of the cylinder member 6.
The tip is brought into contact with the die 2 so that the tip is located on the same plane as the die 2 shaped part.

In this way, in this example, when forging, the blank material B
, the weir cut remainder b2 of the blank body b1 is the forging device 1
Since it is supported on the die 2 so as to be positioned on the mating surface with the punch 5, the weir cut remaining portion b2 is substantially
It is the same as forging a blank material B without a blank material B1, that is, a blank material B with a flat end surface.
Therefore, there is no difference in the timing of the protrusion of the meat due to the step on the end face of the blank lumber body b1, and this ensures that a crack-shaped groove is generated at a portion corresponding to the outer periphery of the weir cut remaining portion b2. It can be prevented.

Thereafter, after raising the punch 5, the rocker arm A is taken out from the forging device 1 and subjected to T under predetermined heat treatment conditions.
After performing the 6 treatments, the flash (paris) a+ formed during forging is removed using a trim die (not shown) to obtain a product.

After that, rocker arm A with this flash a1 removed
The forging process is then carried out to the shot peening process where the surface is polished and the forging process is completed.

In addition, in the above-mentioned example, the case where the forged product is a rocker arm A as an engine part for a vehicle such as an automobile is shown.
Needless to say, this is not the only option.

(Effects of the Invention) As explained above, according to the method of the present invention, a blank material having a weir cut portion protruding from the blank material body is cast, and then this blank material is placed on a die of a forging device using the weir cut portion. After the remaining part is supported so that it is located on the mating surface with the punch, it is compressed and plastically deformed by the die and punch, so that the difference in the timing of the extrusion of the meat due to the step on the end face of the blank body during forging is eliminated. This makes it possible to reliably prevent crack-like grooves from forming in a portion corresponding to the outer periphery of the weir cut remaining portion.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, and FIGS. 1(a) and (b)
2(a) and (b) are longitudinal cross-sectional views showing the forging device before and after forging, respectively, and FIGS. 2(a) and (b) are FIGS.
) is an enlarged view of the main parts. FIGS. 3(a) and 3(b) are views corresponding to FIGS. 2(a) and 2(b) of the conventional example, respectively. 1...Forging device, 2...Die, 5...Punch, A
...Rocker arm (forged product), B...Blank material,
b1 blank main body, b2... weir cutting remainder. Patent applicant Hiroshima Aluminum Industry Co., Ltd. Agent 1) Hiroshi (and 2 others)
(Q) Figure 3 (b)

Claims (1)

[Claims] (1) A method of manufacturing a forged product by forging a blank material cast into a predetermined shape, in which a blank material having a protruding weir cut portion on the main body of the blank material is cast, and then this blank material is forged. A forged product characterized in that the forged product is obtained by supporting the weir cut portion on the die of the device so that it is located on the mating surface with the punch, and then compressing and plastically deforming it with the die and punch. manufacturing method.