JPS59120340A - Forging method of odd-shaped section ring - Google Patents

Abstract

PURPOSE:To produce a ring having an odd-shaped section that has a suitable projection on the bore side in the stage of forging a large diameter ring having a different diametral section by expanding the hole formed in said ring by menas of a hole expanding jig having the outside circumference formed to a prescribed shape. CONSTITUTION:A blank material 1 for a ring is punched and is thereafter subjected to hole-expand forging by using a conventional hole expanding jig 2 and a hole expanding trestle 3, whereby a preform forging 1' is made. A jig 4 having an engraving part 4a is passed in the hole of the forging 1' and while the diameter of the hole is increased by rotating said jig and forging the material, a projecting part 1a is roughly formed on the bore side by the part 4a. The transverse direction of the material 1' is then forged to a prescribed preform size and in succession, a finishing jig 5 having an engraving part 5a is passed therethrough and while the bore thereof is increased by rotating said jig and forging the material, a projecting part 1a of the bore side is formed. The ring shape having an odd-shaped section is thus forged by free forging at a good yield and low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a forging method by free forging of ring gears for Matsubi bombs, gear rims for marine main engines, and other large-diameter ring forged products having different diameter cross sections.

It is well known that a ring rolling mill is easier and more advantageous than free forging in forming a ring-shaped forged product having an irregular cross section.

However, when manufacturing a ring-shaped forged product with a cross section with large irregularities on the inner diameter side (see Fig. 4 (A) to Figure 4), special consideration must be given to the rough shape, or the two-pass IEf)E method, etc. Otherwise, even the method using a ring roll mill is not easy.

It is said that it is extremely difficult to manufacture ring-shaped forged products with irregular cross-sections using the service fee method.
H2MCA), 03), (C), (D)
A ring-shaped forged product with a rectangular cross section that underwent the free forging process shown in , (E), and (F) was cut and formed by machining to form a protrusion on the inner diameter side to have an irregular cross section.

However, in the conventional method using a combination of free forging and machining, (1) there is a lot of waste material removed by cutting, resulting in poor yield.

(11) Since free forging and cutting are performed, costs increase.

011) Forging streamlines (forging flow) by cutting
), the strength near the protrusion on the inner diameter side is weakened.

There were drawbacks such as.

The present invention aims to eliminate the drawbacks of the conventional methods described above and provide a method for forging rings with irregular cross-sections using only free forging, which has a good yield, low cost, and excellent strength. In the proposed method, the 1'th (-3 forging method,
When press-forming the moon into a ring shape, the hole is expanded using a hole expanding jig whose outer periphery is formed into a predetermined shape, and a ring with an irregular cross section having an appropriate protrusion K on the inner diameter side is forged. This relates to a g force building method for rings with irregular cross sections.

Hereinafter, the present invention will be specifically explained in accordance with the steps VC shown in FIGS. 1(A) to (F'). In other words, Figure 1 (
After upsetting the material 1 shown in A) and drilling the hole as shown in FIG. ), hole expansion forging is performed to produce a rough-ground forged product 1'.Then, the rough-ground forged product 1
As shown in FIG. 1(D), a jig 4 having a carved part 4a is passed through the hole 1, and the jig 4 is forged while being rotated to increase the diameter. , a rough protrusion 1a is formed protrudingly on the inner diameter side. Next, the width direction of the material 1' is forged to a predetermined rough size. (1st
(See Figure (6)) Furthermore, the diameter is increased by forging while rotating it through a finishing jig 5 having an engraved part 5a as shown in the opening in Figure 1. .

In addition, in the case 5 for use on A1, as shown in Fig. 1 (F') -1-
A stone ξ5h such as this is provided, and the jig 5^ and rotating groove fI (while continuing the forging press, the top die 6 of the press is brought into even contact with the stopper 5h). -r7
) If the hole is expanded and forged at t, the inner and outer diameters and width of the material will be i'%', ifi.

Dimensions and 7. (Royo, elementary (: A1's ton fH is set to 1
[reactor.

After going through the above steps, a ring shape with an irregular cross section is easily formed by forging the first part. In this case, there is a concern that there will be unnecessary material on the inner diameter side.Since it can be forged with a small machining allowance, the yield is better compared to the conventional method that uses cutting 7J [l King].
Two. The experimental results are 4. For the forged military cap, if the conventional method is 100, the method of the present invention has a yield of 69, which is a 61% improvement in yield and 4c rim-0 (the forging time is almost the same as the conventional method). This reduces the heat treatment type opening and eliminates the conventional method.
If it is 0 [], then the number of heather inventions is 69. Furthermore, the machining time was shortened, with the conventional method having a machining time of 100 and the present invention having a machining time of 75.

In addition, FIGS. 6(A) and 6(B) show the dimensions of an example of a hole expanding jig used in the method of the present invention.

In the present invention, the material is forged into a ring shape 1 [formed] by a free forging method, and the hole is formed using a hole expanding jig whose outer periphery is formed into a predetermined shape. Since the gist of the present invention is a method for forging a ring with an irregular cross-section, which is characterized by forging a ring with an irregular cross-section, which is expanded and pressurized and has an appropriate protrusion on the inner diameter side, It is possible to overcome the shortcomings of the conventional method of combining forging and cutting, and to achieve a practical effect of realizing a method for forging a ring having an irregular cross section with good yield, excellent strength, and low cost. .

Note that even a ring-shaped forged product having an asymmetrical cross-sectional shape in the width direction can be forged by appropriately designing the protrusion of the hole expanding jig.

[Brief explanation of the drawing]

Figure 1 (A), (B), (C), (D>
. 6(A) and 6(B) are schematic explanatory diagrams of an example of a hole expanding jig used in the present invention, FIG. 6(A) is a side view, and FIG. 6(E3) is a side view. (A
Figure 4 (A), (B)
, (C), υ), but) are examples of ring-shaped forged products with irregular cross-sections that can be manufactured according to the present invention k 7J", -4'3.
1: Raw earth moon, 1': Raw earth forged product, Ro: Horse stand for hole expansion, 4: Wild earth moon 1 jig, 5: Finishing earth earth earth moon 1 jig, 5
a: Engraved part, 5h: Stotsuno g, 6: Totsuzodai. rI]I Chapter (α　Figure 4)

Claims (1)

[Claims] When the material is forged into a ring shape using the free forging method, the hole is expanded using a hole expansion jig whose outer periphery is formed into a predetermined shape, resulting in an irregular cross-section ring with an appropriate protrusion on the inner diameter side. A method for forging a ring with an irregular cross section.