JPH02200337A - Manufacture of forged part - Google Patents

Abstract

PURPOSE:To support a blank material on a die without being shaken and to obtain a forged part being free from a forging defect by positioning a supporting part on the spotting surface of a die and a punch with respect to a blank material in which the supporting part is formed as one body. CONSTITUTION:By protruding a molten metal from a mold to the outside periphery of a blank material body b1, a blank material B in which a supporting part b2 is formed as one body is cast. This blank material B is carried into a forging device 1, and supported on a die 2 through each supporting part b2 by positioning each supporting part b2 on the spotting surface of the die 2 and a punch 3. Subsequently, the punch 3 is allowed to descend, and the blank material body b1 of the blank material B is compressed with the die 2 and the punch 3 and brought to plastic deformation. In such a way, even when the blank material B shows a complicated shape, it can be supported stably on the die 2 without being shaken by each supporting part b2. Therefore, the generation of a forging defect such as an underfill, a crack, etc., can be prevented.

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) Generally, Al-3i-Cu alloys, A, Q-3i-
Cu-Mg alloys have good castability and can be heat-treated to provide excellent strength and toughness, so they have been widely used as alloys for casting rocker arms and other engine parts for automobiles and other vehicles. It is used. However, in today's world where there is a demand for higher engine output, the rocker arms and the like are exposed to severe conditions during operation, so there is a further demand for improved mechanical properties such as the strength and toughness. In order to meet this requirement, for example, as disclosed in Japanese Patent Application Laid-Open No. 187539/1987, a blank material is cast from the above-mentioned Al-3i-Cu alloy, and then this blank material is forged. A method is known in which the mechanical properties are improved by doing so.

(Problem to be Solved by the Invention) However, when the shape of the forged product to be obtained, that is, the shape of the die and punch of the forging device, is complex, it is necessary to prevent the blank material from wobbling on the die during forging. It becomes difficult to support the blank material stably, and for this reason, the blank material a is supported on the die b in a tilted state from the normal posture shown by the solid line in FIG. 5, as shown by the imaginary line in FIG. When forged, the compression timing of the blank material a is partially shifted, and plastic deformation does not take place at the same time.As a result, the forged product suffers from M! There was a problem in that there was a risk that large defects would occur.

Therefore, in order to solve the above-mentioned forging defects, it is considered that an extra internal part is integrally formed in the blank material by, for example, casting, and this extra part is brought into contact with the die shape part and used as a support part to prevent wobbling. It will be done.

However, in this case, during forging, the extra thickness is compressed one step ahead of the punch side, which is the opposite side, so there is a risk of local deformation and forging defects such as cracks.

On the other hand, a support pin for preventing wobbling is arranged so that its tip can protrude into the impression due to the spring force of a coil spring so that it can be retracted from the die, and the support pin and the goo-shaped part stabilize the blank material to prevent it from wobbling. However, in this case, the structure of the forging device becomes complicated and the cost of the equipment increases.

The present invention has been made in view of the above, and its purpose is to stabilize the blank material on the die of a forging device by specifying the shape of the blank material to be subjected to forging. The object of the present invention is to provide support, thereby ensuring that a forged product free from forging defects such as underfilling, cracking, and fogging can be obtained without causing a rise in equipment costs.

(Means for Solving the Problem) In order to achieve the above object, the solution of the present invention is a method of manufacturing a forged product by forging a blank material cast into a predetermined shape. By protruding from the blank material body, a blank material is cast, in which a supporting portion for supporting the blank material body on a die of a forging device during forging is integrally formed on the entire outer periphery or a part of the outer periphery of the blank material body. Next, by positioning the support part of this blank material on the mold matching surface with the punch of the die,
The forged product is obtained by compressing and plastically deforming the forged product with the die and the punch while the forged product is supported on the die via the support portion.

(Function) With the above configuration, in the method of the present invention, by causing the molten metal to protrude from the mold, the entire outer periphery of the blank material body or a part thereof is provided with a support portion that supports the blank material body on the die of the forging device during forging. By positioning the support part on the die mating surface with the punch of the die, the blank material integrally formed is supported on the die via the support part, and the blank material is connected to the die and the above-mentioned die. It is compressed and plastically deformed with a punch.

From this, the above blank material (blank material main body) is
Even if the shape is complex, the supporting part allows it to be stably supported on the die without wobbling, and this allows the compression timing of the blank material body during forging, that is, the plastic deformation to occur simultaneously over the entire blank material. As a result, a forged product free from forging defects such as underfilling, cracking, and fogging can be reliably obtained.

In addition, since the support part is located on the die mating surface with the punch, the forging process will result in a flash (
As a result, forging defects such as cracks due to local deformation are reliably prevented.

Furthermore, as mentioned above, since there is no need to provide a support mechanism in the forging device by simply forming the support portion on the blank main body, the structure of the forging device does not become complicated, and therefore a rise in equipment costs can be avoided. The Rukoto.

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

FIGS. 1(a) and 1(b) 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 a first 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 FIGS. 1(a) and 2, this blank material B consists of three bottles whose tips are curved downward at right angles by causing the molten metal to protrude from the mold (not shown) during casting. Support part b2. b2. b2 are integrally formed on the outer periphery of the blank main body b1 so as to protrude outward. Specifically, there are two support parts b2+b on the right end side in the figure.
2, one support part b2 is formed at the left end. These supporting portions b2 stably support the blank material b (blank material main body b+) on the die 2 as the lower mold of the forging device 1 during forging.

Next, the blank material B cast as described above is carried into the forging apparatus 1, and each of the supporting parts b2 is positioned on the die mating surface with a bunch 3, which will be described later, of the die 2.
While supported on the die 2 via each support part b2,
As shown in FIG. 1(b), the bunch 3 serving as an upper die, which is disposed above the die 2 so as to be able to rise and fall, is lowered, and the blank body b1 of the blank material B is separated between the die 2 and the bunch 3.
By compressing and plastically deforming the rocker arm A, the rocker arm A is obtained.

As described above, in this example, the blank material B in which the three support parts b2, b2 + b2 are integrally formed is cast by causing the molten metal to protrude from the mold onto the outer periphery of the blank wood body b1, and this blank material Since B is supported on the die 2 of the forging device 1 via each of the supporting parts b2, the blank material B (blank material main body b+)
Even if it has a complicated shape, it can be stably supported on the die 2 without wobbling by each of the supporting parts b2, and therefore the compression timing for the blank body b1 during forging, i.e. Plastic deformation is carried out simultaneously over the entire structure, thereby making it possible to reliably obtain a rocker arm A free from forging defects such as underfilling, cracking, and fogging.

In addition, in the above embodiment, since each support part b2 is located on the die mating surface with the bunch 3 of the die 2, it can be extruded out of the impression as a flash Al during forging, thereby preventing cracks due to local deformation. Defects can be reliably prevented.

Furthermore, in the above embodiment, the die 2 of the forging device 1 can be
There is no need to provide a support mechanism for the forging device 1, so the structure of the forging device 1 does not become complicated, and a rise in equipment costs can thereby be avoided.

After that, after raising the bunch 3, the rocker arm A
was carried out from the forging device 1 and heated to T6 under predetermined heat treatment conditions.
After the treatment, flash al formed during forging is removed using a trim die (not shown) to obtain a product.

Thereafter, the rocker arm A from which the flash a1 has been removed is carried into a shot beaning process, the surface is polished, and the forging work is completed.

(Second Embodiment) FIGS. 3(a) and 3(b) show the case where the rocker arm A is forged by the forged product manufacturing method according to the second embodiment of the present invention, and the manufacturing procedure is as follows: The second embodiment is the same as the first embodiment except for the shape of the supporting portion b2 formed integrally with the blank main body b1 of B, so a detailed explanation thereof will be omitted.

That is, the blank material B, as shown in FIG.
By causing the molten metal to protrude from the mold during casting, a thin plate-shaped support portion b2 is integrally formed around the entire outer periphery of the blank material body b1 so as to surround the blank material body b1, and the blank material is B (blank material main body b+) is stably supported on the die 2 via the support part b2 by positioning its support part b2 on the die mating surface with the bunch 3 of the die 2 of the forging device 1. is being done.

Therefore, in this embodiment as well, the same effects as in the first embodiment described above can be achieved.

In addition, in the first embodiment, three pin-shaped support parts b2
1 b2. b2 is formed at a predetermined location on the outer periphery of the blank material body 1, and in the second embodiment, the thin plate-shaped support portions b2 are integrally formed on the entire outer periphery of the blank material body 1, but the present invention is not limited to this. The shape and formation position etc. of the forged product as a final product, that is, the die 2, are determined in order to stably support the blank material B (blank material main body b+) on the die 2.
The setting may be changed as appropriate depending on the shape of the shaped portion.

In addition, the formation position of the support part b2 can be easily changed at any position on the outer periphery of the blank body 1 by changing the parting line position of the mold with respect to the blank body b1. The shaped blank material B (blank material main body b+) can be stably supported on the die 2.

Further, in each of the above embodiments, the forged product is the rocker arm A as an engine part for a vehicle such as an automobile, but it goes without saying that the forged product is not limited to this.

(Effects of the Invention) As explained above, according to the method of the present invention, a blank material in which a support portion is integrally formed on the entire outer periphery of the blank material body or a part thereof by causing the molten metal to protrude from the mold, By positioning the support portion on the die mating surface with the punch, the support portion is supported on the die via the support portion. Therefore, even if the blank material (blank material main body) has a complicated shape, it can be stably supported on the die without wobbling by the supporting portion, and plastic deformation can be simultaneously carried out over the entirety. The supporting portion can be extruded out of the impression as a flash, thereby reliably obtaining a forged product free from forging defects such as underfilling, cracking, and fogging. Further, as described above, it is not necessary to provide a support mechanism in the forging device by simply forming the support portion on the blank main body, so that it is possible to avoid an increase in the price of the forging device.

[Brief explanation of the drawing]

FIGS. 1(a), (b) and 2 are the first embodiment of the present invention.
An example is shown, and FIGS. 1(a) and 1(b) are longitudinal sectional views showing a forging device before and after forging, respectively, and FIG. 2 is a plan view of a blank material. Figure 3(a). (b) and FIG. 4 show a second embodiment of the present invention, and a third embodiment of the present invention.
Figures (a) and (b) are equivalent to Figures 1 (a) and (b), and Figure 4 is equivalent to Figure 2. FIG. 5 is a schematic diagram of a conventional example showing how a blank material is supported on a die during forging. 1...Forging device, 2...Die, 3...Punch, A
...Rocker arm (forged product), B...Blank material,
bl...Blank material body, b2... Support part.

Claims (1)

[Claims] (1) A method of manufacturing a forged product by forging a blank material cast into a predetermined shape, in which the molten metal is caused to protrude from the mold, so that the entire outer periphery of the blank material body or a part thereof is formed during forging. By casting a blank material integrally formed with a support part that supports the material body on a die of a forging device, and then positioning the support part of this blank material on the mold matching surface with the punch of the die. , while supported on the die via the support part,
A method for producing a forged product, characterized in that the forged product is obtained by compression and plastic deformation using the die and the punch.