JPS58168453A - Forming method of h-section forging - Google Patents

Abstract

PURPOSE:To reduce the quantity of burr, to improve the yield of a product, and to prevent generation of a defective having undesfill, by executing roughing- down by use of an upper and lower non-symmetrical metallic die, when forging an H-section forging. CONSTITUTION:As for a roughing-down metallic die, a cavity die has an upper and lower non-symmetrical cavity die 3, a slit die line forms no straight line, a split die line of a flash-land 5 and a gutter 6 part, following both ends of the cavity die is positioned at the upper part than the split die line in the cavity die, and said metallic die consists of a punch 1 whose section is an inverted projecting shape, and a die 2 whose section is a recessed shape. A semi-product which is roughed down by use of this metallic die passes through each process of finish-forging, burr-removing and restrike-forging which are usually executed, and it is finished to an H-section forging. According to this method, the rough- forging material is saved, the quantity of generated burr is reduced, and the yield of a product is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention improves both flow to the inner surface of the hole mold by rough punching using a mold with a vertically asymmetric cross-sectional shape.
This invention relates to a method for forming cross-sectional forged products.

Die-forged products are generally designed to have shapes that are easy to die-forge, require few machining steps, and can be made at low cost. Therefore, as shown in Fig. 1, the H-section forged product has an upper die (8),
Die forging is carried out using a die with a vertically symmetrical hole (11) in which the parting line flOi of the lower die (9) passes through the center of the hole.

However, in the case of forging with a conventional metal mold with vertically symmetrical holes, both flows in the lateral direction (X direction in FIG. 1) along the die parting line are larger than in the vertical direction (X direction in FIG. 1). Therefore, in order to make enough land for the entire Rankoku area, the volume of wasteland before entering the land must be reduced very quickly. Therefore, forging not only required a large pressing force, but also increased the amount of paring, resulting in a decrease in production yield and was uneconomical.

In order to eliminate such drawbacks, this invention proposes a method for forming an H-section forged product, which is characterized in that rough punching in the die forging process of the H-section forged product is performed using a die with a vertically asymmetric hole. The effect is that the flow of the material in the vertical direction (y direction) within the hole mold is made redder than in the horizontal direction (x direction), which allows for a good rise and crispness of the material using a relatively small volume of rough ground. The reason is that forged products can be obtained in small quantities.

That is, the present invention provides a method for forging an H-section forged product consisting of the steps of roughing, rough punching, finishing punching, flat punching, and shaping punching, which consists of an upper die with a reversely convex cross section and a concave cross section. , the gist is that the parting line does not match the center of the hole, so rough hammering is performed using a metal mold with a vertically asymmetric hole.

Next, embodiments of the invention will be described with reference to the drawings.

As shown in Figure 2, the hole shape of the rough punching mold is a vertically asymmetrical hole! ! l (It has 111, the split line (4) does not form a straight line, and the split am of the fludge land (i) and gutter (6) that follow both ends of the hole is located above 11111IIm within the hole. , consisting of an upper mold (1) with an inversely convex cross section and a lower mold (2) with a concave cross section.

When designing this metal product, it is designed with the same gm as the conventional one, but since the height of the rib on the lower mold side becomes larger, the itjm surface of the product after rough hitting the upper part, which has a drop slope, is vertical. This results in an asymmetrical surface, but this can be fully corrected by finishing punching performed in the subsequent process.

The product that has been roughly punched using the above mold goes through the usual finishing punching, deburring, and shaping punching processes.
It is finished into a forged product.

Currently, the rib height is 150m1g, the web thickness is 20cm, and the weight is 9
To make a 5-touge H-section forged product, I used a rough ground weight 1145 rim for die forging. On the other hand, for comparison, when the same product was made using a conventional vertically symmetrical mold, it weighed 120 kg.
wasteland was needed.

Therefore, according to the present invention, waste land can be saved, the amount of generated paris can be reduced, and the product yield can be improved.

As mentioned above, this invention not only reduces the amount of chips and improves the product yield by performing rough punching using a mold with vertically asymmetrical holes, but also prevents the occurrence of defective products with insufficient thickness due to insufficient thickness. It is virtually eliminated, and the life of the mold can be significantly extended.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the hole part of a mold with vertically symmetrical holes used for conventional rough punching, and Fig. 2 is a sectional view of the hole part of a mold with vertically asymmetrical holes used in the present invention. be. In the figure 1...Upper die, 2-Lower die, 3...Vertically asymmetrical hole type, 4...Split die line, 5...Fludge land, 6
...Gatsuta, 7--Wasteland.

Claims (1)

[Claims] In the forging of H-section forged products, which consists of the steps of roughing, rough punching, finishing punching, deburring, and shaping, the die consists of an upper mold with a reverse convex cross section and a lower mold with a concave cross section, and the parting line is aligned with the hole. A method for forming an H-section forged product characterized by rough punching using a vertically asymmetrical mold that does not coincide with the center of the mold.