JP2725988B2 - Regeneration method of die for crankshaft forging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating a mold for forging a crankshaft for regenerating and using a mold having a plurality of mold members.

[0002]

2. Description of the Related Art For example, when a crankshaft, which is an automobile part, is forged, it is necessary to subject a workpiece to crushing, roughing, and finishing. For this reason,
This type of forging die is provided with a plurality of pairs of upper and lower mold members corresponding to each process, and the work is conveyed to each mold member sequentially through the conveying means, so that the work is roughened. Various forming steps from the forming step to the finish forming step are continuously performed.

[0003] Incidentally, the mold member is liable to cause mold drooping due to wear as the frequency of use increases, so that it is not possible to obtain a forged product maintaining desired quality accuracy. It will be the life limit. Mold members that have reached the mold life limit for each process are generally discarded, but the mold life of the forging mold used under severe conditions is short, so the mold cost is a product cost. It is added at an extremely large ratio on cost.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. Hei 1-210133, the surface hardened layer of the mold which has become unusable due to its life or the like is removed by blasting, and then the engraved portion is cut and removed. There is known a method of regenerating a mold in which a die-sinking electric discharge machining is performed later and a plate is fixed to the bottom of the mold as required.

[0005]

However, the above-mentioned prior art is a correction method in which a new engraving process is performed by cutting and removing the engraved portion, and a deficient portion is reinforced by a plate. Although the cost can be reduced as compared with the case where the used mold member is disposable, the actual processing step becomes considerably complicated. Therefore, a problem has been pointed out that the manufacturing cost of the mold is not significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to efficiently utilize a mold member provided in each step and to effectively reduce the manufacturing cost of a whole mold. It is an object of the present invention to provide a method for regenerating a mold for crankshaft forging capable of performing the above.

[0007]

In order to achieve the above object, the present invention provides a method for crushing, roughing and finishing .
A pair of first nozzles provided corresponding to each molding process
Class sequentially forging continuously work at optimum third mold part
A method for reclaiming a mold for fork shaft forging, comprising:
A pair of the third mold members that have become unusable in the shaft forming process
A regular pair of the second
Molding surface of each of the third mold members in comparison with the mold member
To the crankshaft crankpin
Correction and finishing by the weld overlay
By doing so, a pair of the third mold members is replaced with a pair of the second mold members.
A pair of members that have become unusable in the rough forming process
The second mold member is replaced with a regular mold used in the crushing process.
Compared to the pair of first mold members, the second mold member
On each molding surface, the crankpin of the crankshaft
In response to the
Finish and finish, and the crankshaft
Deleted according to the excess weight portion of the balance weight
By applying a correction and finishing process,
A second type member is a pair of the first type members .

[0008]

According to the method for regenerating a mold for crankshaft forging according to the present invention, when the mold member on the side of the finish forming step becomes unusable due to wear or the like, the required thickness of the mold member on the side of the finish forming step is reduced. The mold member on the side of the finish forming step can be used as a mold member on the side of the rough forming step only by performing a correction process such as a filling repair process and a deleting process. Therefore, to produce only the mold members of the finish forming process side is newly used as a mold member of rough forming process side only subjected to minimal correction process when it unusable in the molding process the mold member is finished ,
Furthermore, when it becomes unusable in this rough forming process,
As a mold member of a molding process side crushing in the correction process, sequentially, it can be used, reducing the cost of manufacturing the entire mold by utilizing mold member efficiently is readily accomplished.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a method for regenerating a crankshaft forging die according to the present invention.

In FIG. 1, reference numeral 10 denotes a forging die to which the recycling method according to the present embodiment is applied. The mold 10 includes a crushing first mold member 12 and a rough molding second mold member 1 that are sequentially arranged in the direction of arrow A in accordance with a forging process.
4, the third mold member 16 for finish molding, and the trimming mold 1
8 are held between the lower die plate 20 and the upper die plate 22.

The first mold member 12 has a lower mold 24 and an upper mold 26. The lower mold 24 is supported by a lower pressing plate 28a via a spring 30a. It is supported on the plate 32a via a spring 34a. Between the lower mold 24 and the upper mold 26, a first cavity 38 corresponding to a crushing shape of a forged crankshaft 36 (see FIG. 2) for crushing a raw material (work) (not shown). Is formed.

The second mold member 14 includes a lower mold 40 supported on the lower pressing plate 28b via a spring 30b, and a spring 34b on the upper pressing plate 32b, similarly to the first mold member 12.
And a second cavity 44 corresponding to the shape of the crankshaft 36 for rough forming is formed between the lower mold 40 and the upper mold 42. Third
Similarly, the mold member 16 includes a lower mold 46 supported on the lower pressing plate 28c via a spring 30c, and an upper mold 48 supported on the upper pressing plate 32c via a spring 34c. A third cavity 50 is formed between the mold 46 and the upper mold 48 according to the shape of the crankshaft 36 for finish molding.

When the crankshaft 36 is forged by the mold 10 having such a configuration, first, a material (not shown) is placed in the first cavity 38 of the first mold member 12.
Under the action of the lower pressing plate 28a, the upper pressing plate 32a, and the springs 30a, 34a, the lower mold 24 and the upper mold 26 are pressed to perform crushing.

Next, the crushed molded product is gripped by a transporting means (not shown), transported in the direction of arrow A, and placed in the second cavity 44 of the second mold member 14. The crushed molded product in the second cavity 44 is subjected to rough molding under the pressing action of the lower mold 40 and the upper mold 42, and then transferred to the third cavity 50 of the third mold member 16, where the lower mold 46 and the upper mold 46 are moved. Type 48
Finish molding is carried out via. Then, the finished molded product is carried into the trimming mold 18 and a predetermined trimming process is performed to obtain a crankshaft 36 as a forged product.

By the way, if the forging operation is continued, the molding surfaces of the first to third mold members 12, 14, and 16 are worn, and the first to third mold members 12 to 14 are worn out. 3
The mold members 12, 14, 16 tend to be unusable in each step. Therefore, the regeneration method according to the present embodiment is performed on the mold 10.

That is, the third mold member 16 for finish molding.
While only the new mold is newly manufactured, the third mold member 16 which has been used for finish molding and has reached the end of its life is overlaid on the insufficiently shaped portion corresponding to the mold structure of the second mold member 14 for rough molding. After performing the repairing process and performing the deleting process and the finishing process on the surplus shape portion, the third mold member 16 is reused as the second mold member 14 for rough forming. Further, for the second mold member 14 which has been used for rough forming and which has reached its life limit, a buildup repair process is performed on an insufficiently shaped portion corresponding to the mold structure of the first mold member 12 for crushing, and a surplus shape is formed. The part is subjected to a deleting process and a finishing process, and the second mold member 14 is removed.
Is recycled as the first mold member 12 for crushing. In addition,
First mold member 12 used for crushing and having a limited life
Is discarded.

In this case, the first to third cavities 3 of the first to third mold members 12, 14, 16 used in each step are provided.
8, 44, and 50 have substantially similar basic shapes. For this reason, when the third mold member 16 is recycled as the second mold member 14, as shown in FIG. 3, the lower mold 46 and the upper mold 48 use the crank pin portion 36a of the crank shaft 36 (see FIG. 2). Part 5 corresponding to)
It is only necessary to perform a correction process for providing 2a and 52b. The overlaid portions 52a and 52b are actually provided by performing a welding process on the molding surfaces of the lower die 46 and the upper die 48.

On the other hand, when the second mold member 14 is to be reused as the first mold member 12, the lower mold 40 and the upper mold 42 have a portion corresponding to the crank pin portion 36a as shown in FIG. In addition to performing a correction process for providing the overlaid portions 54a and 54b, as shown in FIG. 5, the removed portions corresponding to the portions where excess thickness is provided in order to prevent underfilling of the balance weight portion 36b (see FIG. 2). A correction process (cutting process) for providing 56 and a finishing process thereof are performed.

Further, as shown in FIG.
The second cavity 44 has a balance weight portion 36b.
Are provided. When the second mold member 14 is used as the first mold member 12, for example, the load is increased from 5000t to 1000t to 2t.
By adjusting the second mold member 14 to 000t, the correction processing of the second mold member 14 becomes unnecessary.

As described above, in the present embodiment, the third mold member 16 and the second mold member 14 which cannot be used on the side of the finish forming process (post-process) can be modified with extremely small processing man-hours and minimal correction. , The third mold member 16 and the second mold member 14 can be reused as the second mold member 14 and the first mold member 12 on the rough forming process side (previous process). Moreover, the third mold member 16 and the second mold member 14
Keeps the function of the forging die, so that when these are newly used as the second die member 14 and the first die member 12, forging defects such as deformation and cracks are hardly generated.

As a result, the life of the entire mold 10 can be greatly increased, and at the same time, the repairing process can be simplified and performed quickly, and the manufacturing cost of the mold 10 can be considerably reduced. The effect is obtained. For this reason, there is an advantage that the unit price of the forged product is easily reduced.

[0022]

According to the method for regenerating a die for forging a crankshaft according to the present invention, the following effects and advantages can be obtained.

The mold member on the side of the finish forming process which has become unusable due to wear or the like can be subjected to only a minimum repairing process such as a necessary build-up repairing process and a deletion process, thereby obtaining the mold member on the side of the finish forming process. Can be used as a mold member on the rough forming step side. Therefore, only the mold member on the side of the finish forming process is newly manufactured, and when this mold member becomes unusable in the finish forming process, it is only necessary to perform a predetermined correction process and to sequentially use the mold member on the side of the rough forming process. The manufacturing cost of the entire mold can be easily reduced by efficiently utilizing the mold member.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a forging die for performing a reproducing method according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a crankshaft forged by the mold.

FIG. 3 is an explanatory longitudinal sectional view of a third mold member constituting the mold.

FIG. 4 is an explanatory longitudinal sectional view of a second mold member constituting the mold.

FIG. 5 is another sectional explanatory view of the second mold member.

[Explanation of symbols]

10 molds 12, 14, 1
6 ... Mold member 24 ... Lower mold 26 ... Upper mold 36 ... Crankshaft 38 ... Cavity 40 ... Lower mold 42 ... Upper mold 44 ... Cavity 46 ... Lower mold 48 ... Upper mold 50 ... Cavity 52a, 52b, 54a, 54b ... Meat Prime part 56 ... deleted part

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroki Saigo 19 Matsuyama-cho, Moka-shi, Tochigi Honda Motor Co., Ltd. Tochigi Seisakusho Co., Ltd. (56) References JP 50-33165 (JP, A) -210133 (JP, A)

Claims (1)

(57) [Claims] 1. A method for crushing, rough forming and finish forming .
A pair of first to first pairs respectively provided corresponding to the forming process
Crank sequentially forging continuously work type 3 members
A method for regenerating a shaft forging die, wherein the pair of the third
The mold member is moved to a pair of regular fronts used in the rough forming process.
In comparison with the second mold member, each component of the third mold member is formed.
On the surface, fit the crankpin of the crankshaft
Correction and finishing processing by weld overlays
By applying a pair of third mold members to the pair of third mold members.
A pair of second mold parts which are made into a two-mold member and are unusable in the rough forming step
The material is used in the crushing process and a pair of regular
Forming each of the second mold members in comparison with the first mold member;
On the surface, corresponding to the crankpin of the crankshaft
Correction and finishing by the weld overlay, which is the weld overlay
And balance the crankshaft.
Correction by deletion corresponding to the excess
By performing the finishing process, the pair of second mold members
A crank as a pair of the first mold members
How to regenerate shaft forging dies.