JPS6310194Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a mold used in a closed die forging device.

(Prior art) Closed die forging equipment is used to forge products with high precision and high dimensional accuracy.
Even when such a mold is used, it is necessary to make the clearance between the molds as small as possible, especially in order to improve molding accuracy and prevent burrs from forming. However, when the clearance is made small in this way, the air remaining in the mold during molding cannot escape, and as molding progresses, this creates high pressure and gets between the material to be molded and the mold surface, impeding their adhesion. However, this can lead to problems such as partial unprocessed parts in the product. This is especially a problem when the workpiece is a non-ferrous material, and especially in the case of superplastic materials, the deformation resistance when forming in the superplastic region is small, so a small amount of residual air can cause the unformed part to break. If the size increases, the originally excellent transferability may have the opposite effect.

For this reason, in the case of closed molds, measures are taken to allow the high-pressure air to escape during molding by creating minute air vent holes in the mold, but as a practical matter, it is important to properly locate the air vents. This is difficult, especially in the case of superplastic materials, where a part of the material can get into the air vent holes due to plastic flow, making it difficult to remove the product from the mold and causing problems such as burrs.

(Purpose) The present invention was developed in view of the above problems, and its purpose is to improve the release of high-pressure air, and to prevent burrs from forming on the product or making it difficult to release from the mold. The purpose of the present invention is to provide an improved die forging die.

(Structure) Therefore, details of the present invention will be explained below based on illustrated embodiments.

FIG. 1 shows an example of a mold according to the present invention. Below the male mold 2 (upper mold) attached to the tap 1, there is a female mold 3 facing the anvil 4.
is fixed. This female die 3 constitutes the characteristic parts of the present invention, and includes a bottom plate 31, a cutting die 32, and a presser foot 3.
A plate-shaped cutting die 32 engraved into the shape to be formed is placed on the top surface of the bottom plate 31 which is fixed to the anvil 4, and a presser foot 33 is integrally attached from above with bolts 34. is fixed.

Therefore, when a heated workpiece is placed on the female die 3 mentioned above and the male die 2 is lowered from above, the air trapped between the male die 2 and the female die 3 is released. The cutting die 32, the bottom plate 31, and the cutting die 3
2 and the presser foot 33, a minute gap θ ₁ ,
It leaks to the outside from θ ₂ (Figure 2). When the pressurizing action by the male die 2 further progresses from this state, the cutting die 32 is deformed into a flat shape within its elastic limit at the final stage, and the gaps θ ₁ and θ ₂ that existed between the two are reduced.
disappears and accurate molding action is performed.

According to experiments, the closed type is a male type with a diameter of 30 mm,
When constructed with a 0.3 mm thick cutting die made of SK4 material, good molding action and reliable air venting action were achieved when the gap between the top and bottom of the cutting die was 0.1 mm or less.

In the embodiment shown in FIG. 3, the cutting die 32' and the presser foot 33' are integrated and mounted on the bottom plate 31'.
and the bottom plate 31', and when the male mold 2 is lowered to its lowest position, it becomes a completely sealed mold as in the above-described embodiment, and the required molding process is performed.

(Effects) As described above, according to the present invention, the lower mold of the closed mold is divided into at least two members along the plane perpendicular to the direction of load action and including the carved part, so that the molding process The gas trapped between the upper mold and the lower mold can be leaked to the outside through the gap between the parts, preventing the occurrence of unformed parts due to residual gas, and also preventing the final mold from forming. Since these members are brought into close contact with each other by causing deformation within their elastic limits during the pressing step, it is possible to repeatedly mold a final molded product without burrs or the like.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a device showing one embodiment of the present invention, Fig. 2 is an enlarged view of the main parts of the same device, and Fig. 3 is an enlarged view of the main parts showing another embodiment of the invention. It is a diagram. 1... Tap, 2... Male type, 3... Female type, 31
... Bottom plate, 32 ... Cutting die, 33 ... Presser foot.

Claims (1)

[Scope of utility model registration request] In a closed die forging die that covers the entire surface of the workpiece at the final stage of processing, the lower die constituting one of the closed dies is aligned with a surface perpendicular to the direction of load action and including the carving die part. What is claimed is: 1. A forging die comprising at least two divided members, characterized in that a gap is provided between the members so that they are deformed within an elastic limit and brought into close contact with each other in the final stage of processing.