JPS6326230A - Forging method for hollow part having flange and boss - Google Patents

Abstract

PURPOSE:To forge two desired hollow parts at a time by compressing a pair of cylindrical material fitted from outside to a mandrel in axial direction by a punch, deforming the butted part of the material to widen it sideways, and leading it to a concave part for flange forming. CONSTITUTION:Cylindrical materials 1, 2 fitted from outside to a mandrel 3 are compressed in axial direction by a punch 4 and a knockout punch 9 with the materials cramped by an upper die 5 and a lower die 6. The butted part of the materials 1, 2 is widened sideways and led into a concave part 15 for flange forming and hollow parts 1a, 2a having flanges 18, 19 and bosses 20, 21 are formed. When the punch 4 and the upper die 5 etc. are raised, and the parts 1a, 2a are separated from the mandrel by the punch 9, tips of flanges 18, 19 are cut off by clamped part 17, and two parts 1a, 2a are taken out simultaneously. Thus, two desired hollow parts can be forged at a time.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a method of forming a cylindrical material having a flange and a boss by compressing it in the axial direction and upsetting the cylindrical material while it is fitted onto a mandrel. This invention relates to an improvement in a forging method for forging hollow parts.

(Prior art) After the material is fitted around the mandrel and compressed in the axial direction to make the central part protrude outward to form a bent part, the outer periphery of this bent part is cut off. A forging method is known in which two hollow parts having a flange and a boss separated at the bent portion are manufactured by doing so.

In this method for forging hollow parts, after forging the bent part, it is necessary to remove the material from the press mold and cut out the outer periphery of the bent part, which makes the manufacturing process complicated.
There has been a problem in that the outer diameter of the flange is reduced by cutting off the outer circumferential portion of the bent portion, making it difficult to form a large diameter flange.

(Objective of the Invention) The present invention was made to solve the above technical problem, and it is possible to easily forge a hollow part of a predetermined shape without performing the above cutting process, and also to make it possible to forge a hollow part with a large diameter. A method for forging a hollow part having a flange and a boss capable of forming a flange is provided.

(Structure of the Invention) The present invention provides a forging method for forming a hollow part having a flange and a boss by compressing a cylindrical material in the axial direction and upsetting the cylindrical material while it is fitted onto a mandrel.
A pair of cylindrical materials are overlapped in the axial direction and fitted onto the mandrel, and the outer peripheral surface of the end of the image material is restrained by an upper mold and a lower mold each having a restraining part for flange forming, and then punched. The drawing material is pressurized in the axial direction to expand and deform the abutting portions outward, and the abutting portions are introduced into the restraining portion to form a flange, thereby forming a hollow part having a flange and a boss into two parts. The pieces are forged at the same time.

According to the above configuration, the abutting portions of the pair of cylindrical materials are introduced into the flange forming recess, and flanges of a predetermined shape are formed while being restrained by the recess,
Two hollow parts with flanges and bosses will be forged at the same time.

(Example) FIG. 1 shows a press mold structure used to carry out the method for forging hollow parts according to the present invention.

This press type structure includes a mandrel 3 that supports a pair of cylindrical materials 1.2, a punch 4 that compresses the cylindrical materials 1.2 in the axial direction, and a cylindrical material 1 located above. It includes an upper mold 5 that restrains the upper outer circumferential surface, and a lower mold 6 that restrains the lower outer peripheral surface of the cylindrical material 2 located below.

The punch 4 has a punch holder 3a corresponding to the mandrel 3.
It is supported so that it can be raised and lowered along the same line, and is also configured to be pushed down by a press mechanism (not shown). An upper mold 5 is disposed outside the punch 4, and the upper mold 5 is held by an upper mold holder 7 and an upper mold holding ring 8 screwed onto the upper mold holder 7.

Further, the lower die 6 is held between the inside and outside by a knockout punch 9 and a lower die holder 10, and a lower die holding ring 11 screwed onto the lower die holder 10;
It is held from above and below by a spacer 12 disposed inside the lower die holder 10.

The knockout punch 9 is supported along the lower die 6 so as to be able to move up and down, and the lower end of the knockout punch 9 and
The upper end portion of the knockout pin 14 supported by the spacer 13 is integrally connected.

As shown in FIG. 2, a recess 15 is formed inside the upper end of the lower mold 6, and a restraining portion 16 is formed between the recess 15 and the lower surface of the upper mold 5 to form a flange of a hollow part, which will be described later.
is starting to form. Further, a locking portion 17 is formed on the circumferential surface of the recess 15, into which a part of the flange of the hollow component located above is introduced, and this flange is later locked to the lower mold 6 for stopping. .

In order to forge a hollow part having a flange and a boss using the press mold structure constructed as described above, first, as shown in Fig. 3, the cylindrical materials 1.2 are stacked in the axial direction, After the lower outer circumferential surface of the lower cylindrical material 2 is restrained by the lower mold 6 by being fitted onto the metal 3, the upper mold 5 is lowered and the upper outer peripheral surface of the upper cylindrical material 1 is restrained by this upper mold 5. At the same time, in this state, the punch 4 is pressed down to press the upper end surface of the upper cylindrical material 1 downward. As a result, the image material 1.2 is compressed in the axial direction between the punch 4 and the knockout punch 9, and the abutting portion of the image material 1.2 is expanded and deformed laterally.

That is, the abutting portion of the picture material 1.2 is located opposite the recess 15 provided inside the upper end of the lower die 6, and the outer peripheral surface thereof is open, so that the abutting portion of the image material 1.2 is exposed to the compressive force of the punch 4. When the picture materials 1 and 2 are deformed, the flow of the materials is concentrated in the recess 15, and the abutting portions are deformed and expanded laterally.

Next, as shown in FIG. 4, when the punch 4 and the upper mold 5 are further lowered, the abutting portions of the picture materials 1 and 2 are further moved laterally along the lower surface of the upper mold 5 and the upper surface of the recess 15. It extends, and its tip comes into contact with the circumferential surface of the recess 15 .

Then, as shown in FIG. 5, when the punch 4 and the upper mold 5 are pushed down until the lower surface of the upper mold 5 comes into contact with the upper surface of the lower mold 6, the restraint formed by the recess 15 and the lower surface of the upper layer 5 The portion 16 is filled with the abutting portion to form a flange 18.19 having a predetermined shape.
19 and a boss 20.21 is formed. Also, the flange 18 of the upper hollow part 1a
is locked to the lower mold 6 by introducing the tip part into the locking part 17.

To take out the hollow parts 1a, 2a formed as described above, first, as shown in FIG. 6, the punch 4, upper die 5, etc. are raised to release the upper surface of the hollow part 1a. In this case, since the flange 18 of the upper hollow part 1a is locked to the lower mold 6 by the locking part 17, it is possible to prevent the hollow part 1a from moving upward together with the upper mold 5.

Therefore, both parts 1a and 2a can be removed from the press mold at the same time as described later. That is, as shown in FIG. 7, the knockout bunch 9 is pushed up and the hollow part 1 is removed.
a, 2a with core gold 3 to 1! By removing the lli,
Both parts 1a and 2a can be taken out at the same time.

Also, the hollow part 1a is removed by the knockout punch 9.
, 2a, the tip of the flange 18 introduced into the locking portion 17 receives a shearing load and is automatically cut off.

A pair of cylindrical materials 1.2 fitted around the mandrel 3 in this way
The flanges 18 and 19 of a predetermined shape can be simultaneously formed by compressing the flange in the axial direction and expanding and deforming the abutting portion laterally and introducing it into the flange forming restraint part 16. Therefore, unlike the conventional example, there is no need for the complicated process of removing the forged product after press working and separating it into three parts.
a.

Two pieces of 2a can be forged at the same time.

Further, the outer diameter of the flange 18.19 is formed according to the inner diameter of the recess 15, so that a sufficient size can be ensured, and the flange 18.19 can be formed into an appropriate shape. That is, the above flanges 18.19
is molded while its outer surface is restrained by the restraining part 16, so the corner part of the curved surface is formed with a large radius of curvature.
It is possible to prevent the formation of droop, etc., and to form the flanges 18 and 19 in an appropriate shape corresponding to the restraining portion 16.

In the above embodiment, a concave portion 15 formed in the lower mold 6 and the lower surface of the upper mold 5 form a restraining portion 16 for flange forming, but the structure of this restraining portion can be modified in various ways. For example, as shown in FIG. 8, on the upper end surface of the lower mold 6a,
The outer circumferential restraint ring 23 is fixed by the ring presser 22,
The restraining portion 24 may be formed by the inner circumferential surface of the outer peripheral restraining ring 23, the lower surface of the upper mold 5a, and the upper surface of the lower mold 6a.

Further, as shown in FIG. 9, an outer circumferential restraining ring 26 constituting the outer circumferential restraining portion 25 is fitted onto the upper outer periphery of the lower mold 6b so as to be freely lowerable W, and this outer circumferential restraining ring 26 is arranged below. While being biased upward by the compression spring 27,
The rising range may be restricted by the ring presser 28.

In this case, as shown in FIG. 10, the cylindrical material 1.
2 is compressed in the axial direction, and the abutting portion becomes the restraining part 2.
When the hollow part 1 is introduced into the hollow part 5 and its tip comes into contact with the inner circumferential surface of the outer circumferential restraining ring 26, as shown in FIG.
As the flanges 18 and 19 of a and 2a are formed, the outer circumferential restraining ring 26 is pushed down against the biasing force of the compression spring 27. Therefore, during the forming process of the flange 18.1, resistance is prevented from occurring between the outer circumferential surface and the restraining portion 25 of the flange 18.1.
9 can be prevented from deforming. However, if the inner circumferential surface of the restraining portion 25 that the outer circumferential surface of the flange is, 19 abuts is fixed, the inner circumferential surface is compressed during the forming process of the flanges 18 and 19. When descending along Fj, frictional resistance occurs and the outer circumferential portion of the flange 18, 19 may curve upward due to this low frictional resistance. In this case, the outer circumferential restraining ring 26 is attached to the flange 18.1 according to the amount of compressive deformation of the flange 18.19.
9, the frictional resistance described above does not occur, and the flanges 18 and 19 can be prevented from being bent.

After forging the hollow parts 1a and 2a as described above, as shown in FIG.
By pushing up a and 2a to separate them from the mandrel 3,
Both parts 1a and 2a can be taken out.

(Effects of the Invention) As explained above, the present invention compresses a pair of cylindrical materials fitted around a mandrel in the axial direction with a punch, deforms the abutting portions to expand laterally, and By introducing the abutting portion into the recess for flange forming provided between the lower molds, the flanges of the upper and lower pair of hollow parts are molded simultaneously in a separate state, making it possible to separate the two parts after press working. It is possible to simultaneously forge two hollow parts having flanges and bosses with a simple configuration.

In addition, since there is no need to cut the outer circumferential part of the flange, it is possible to prevent the outer diameter of the flange from decreasing, and to ensure a sufficient size, as well as to maintain an appropriate shape according to the restraint part. A flange can be formed.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a specific example of the press die structure used in carrying out the present invention, FIG. 2 is an enlarged cross-sectional view showing the main parts of the press die structure, and FIGS. 3 to 7 are the press die structures described above. 8 and 9 are cross-sectional views showing specific examples of the press die structure, and FIGS. 10 to 12 are the press die structures shown in FIG. 9 above. FIG. 3 is a sectional view showing another example of actual flow according to the present invention. 1.2... Cylindrical material, 1a, 2a... Hollow parts,
3... Core metal, 4... Punch, 5.5a, 5b...
Upper mold, 6.6a, 6b-・Lower mold, 16, 24.25・
...Restriction part for flange forming, 18.19...Flange, 20.21...Boss. Patent Applicant Mazda Co., Ltd. Agent Patent Attorney Etsushi Kotani Patent Attorney Chief 1) Masayuki Patent Attorney Yasuo Itaya Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] 1. In a forging method that forms a hollow part having a flange and a boss by compressing the cylindrical materials in the axial direction and upsetting the cylindrical materials fitted around the mandrel, the pair of cylindrical materials are While overlapping the two materials in the axial direction and fitting them onto the mandrel, the outer circumferential surfaces of the ends of both materials are restrained by upper and lower molds equipped with restraining parts for flange forming, and then the image materials are axially aligned with a punch. By applying pressure to expand and deform the abutting portions outward, and introducing the abutting portions into the restraining portion to form a flange,
A method for forging a hollow part having a flange and a boss, characterized in that two hollow parts having a flange and a boss are forged at the same time.