JPH08309469A - Method for forming parts - Google Patents

Abstract

PURPOSE: To provide a method for forming parts without shear droop or roll over in corners. CONSTITUTION: This is a forming method for plastically working boss-attached or drum-shaped parts, such that the end face of the boss or that of the inner flange 6a of a part 6 after the primary working is pressurized in the direction of the inner corner 6c, and that the material is simultaneously subjected to reverse ironing and allowed to flow to the outer corner 6d from at least two directions. Consequently, the part 6 is plastically worked while shear droop in the outer corner 6d is suppressed, enabling a good quality part 6 to be formed without shear droop or roll over in the inside and outside corners 6c, 6d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming bossed parts and drum-shaped parts.

[0002]

2. Description of the Related Art Conventionally, for example, a part a shown in FIG.
There are those in which a boss b is provided on the surface of, and those having a drum shape as shown in FIG. Conventionally, these parts are manufactured by cutting a thick material or by plastic working.

Further, when these parts are subjected to plastic working, there is a problem that the root (R) of the boss b and the corner portion of the outer flange c becomes large, causing sagging, which lowers the working accuracy.

For this reason, various methods for suppressing this sagging have been conventionally proposed. For example, when a part is manufactured by plastic working and cutting a material with excess plate thickness, by processing to a predetermined size during final cutting, the excess plate can be obtained even if sagging occurs in plastic working It is processed using thick material.

Further, the following method is adopted as a sagging suppressing method by plastic working. (1) Multi-step drawing method (2) Ironing method (3) Multi-step drawing + ironing method (4) Zukumi method (axial compression method + ironing method) (5) Reverse ironing method

The multi-step drawing method (1) is a method of drawing the root of the boss b and the corner of the flange c in multiple steps as shown in FIG. 9 (a). It is effective in suppressing the decrease in thickness and increasing the thickness.

The ironing method of the above (2) is a method in which the material a constrained by the die d or the punch f is fluidized while being squeezed by the punch f or the die d as shown in FIG. 9B. Is.

Further, the multi-step drawing + ironing method (3) is a method combining the above (1) and (2), and the throttling method (4) is a boss b or A method of molding the boss b and the flange c while pressing the flange c from the axial direction,
In the reverse ironing method of (5), as shown in (d) of FIG.
And a method of squeezing from the end portion side of the flange c and is a method often used for plastic working.

[0009]

However, in the method of manufacturing a part by cutting a thick-walled material, it takes time to process and productivity is poor, and the yield of the material is poor, so that the part is expensive. There was a problem.

Further, in the plastic working methods of the above (1) to (5), the number of working steps is large, and the shape of a workable part is limited, so that some parts cannot be manufactured or some can be manufactured. Since the root of the boss and the corners of the flange are sagged, there is a problem that after the plastic working using a material having an excessive thickness, it is necessary to finish the cutting into a regular size.

Further, in the Zummi method of (4) and the reverse ironing method of (5), defects such as overlapping of meat as shown in (e) of FIG. 9 occur at the inner corners of the boss b and the flange c. There was a problem.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to form parts for forming bossed parts and drum parts while suppressing defects such as sagging and overlapping. Is to provide a method.

[0013]

In order to achieve the above object, a molding method of a part according to the present invention is a molding method for plastically working a bossed part or a drum-shaped part, and a boss of a part which is primarily processed. By pressurizing the end face and the flange end face in the corner direction, and at the same time, inverting and squeezing the material to flow from at least two directions to the corner part, the parts are plastically worked while suppressing the sagging of the corner part.

[0014]

By the above method, a highly accurate component having no sagging at the corner can be obtained. Also, in the case of parts with a shape having an inner flange and an outer flange, the material of the inner and outer flanges flows to the corners of the outer flange by squeezing the inner and outer flanges while pressing the end surface of the inner flange. Therefore, the excess material does not cause defects such as overlapping in the inner corner portion of the inner flange.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment of the present invention is shown in FIG.
It will be described in detail with reference to the drawings shown in FIGS. FIG. 1 shows a mold used for molding parts. The mold includes a fixed inner die 1, a fixed outer die 2 provided around the fixed inner die 1, and a movable pad provided between the dies 1 and 2. 3 and a movable press punch 4, and a movable punch 5 provided above the movable pad 3.

The fixed inner die 1 and the fixed outer die 2
Tapered surfaces 1a and 2a are formed at the corners of the movable pad 3 and the corners of the movable pad 3 are arcs having the same shape as the inner corners of the component 6 to be molded.

In molding the component 6, first, the component 6
Is processed into a drum shape, and the part 6 that has been processed
As shown in FIG. 1, the end surface of the inner flange 6a is brought into contact with the upper surface of the movable pressing punch 4, and the outer flange 6b is positioned at the interval 7 between the movable pad 3 and the fixed outer die 2.

Next, in this state, the movable punch 5 is lowered to sandwich the bottom of the component 6 between the movable punch 5 and the movable pad 4.

Next, in this state, the movable punch 5 is further lowered while pressing the end surface of the inner flange 6a by the movable press punch 4, as shown in FIG. As a result, the inner flange 6a and the outer flange 6b of the component 6 are reverse-ironed so that the material is made into the inner corner portion 6 as shown in FIG.
While flowing toward c and the outer corner portion 6d,
Since the end surface of the inner flange 6a is pressed by the movable pressing punch 4, more material flows to the inner corner portion 6c.

At this time, the radius (R ') of the inner corner portion 6c is set to be larger than the radius (R) of the outer corner portion 6d in advance, so that the material reaching the inner corner portion 6c is further as shown in FIG. As indicated by the arrow A in (a), it flows toward the outer corner portion 6d.

This prevents defects such as overlapping due to excess material from occurring inside the inner corner portion 6c and the outer corner portion 6d, and
The outer flange 6 is formed on the outer corner portion 6d by reverse ironing.
Since the material flowing from the b side and the material flowing from the inner flange 6a side collide with each other as shown in FIG. 3B to suppress the sagging, the sagging of the outer corner portion 6d can be suppressed.

The fixed outer die 2 of the first embodiment described above may be a movable outer die.

(Second Embodiment) In the second embodiment, the mold used in the molding method of the component 6 having the outer flange 6b is the mold of the first embodiment except that the movable pressing punch 4 is removed. It is composed.

First, the component 6 having the outer flange 6b subjected to the primary processing is set as shown in FIG. 4, and the movable punch 5 is lowered to sandwich the component 6 between the movable punch 5 and the movable pad 3.

Next, when the movable punch 5 is further lowered in this state, the end surface of the bottom of the component 6 is pressed by the taper surface 1a of the fixed inner die 1 and the material flows toward the corner 6d, and at the same time the movable pad is moved. The material of the outer flange 6b squeezed between the fixed outer die 3 and the fixed outer die 2 is also the outer corner portion 6
Flow toward d.

As a result, the materials flowed from the two sides at the outer corner portion 6d collide with each other as shown in FIG. 5 to suppress sagging, so that the inner corner portion 6c has no overlapping defects and the outer corner portion 6c. 6d-free parts 6
Will be obtained.

In the second embodiment, the fixed outer die 2 may be a movable outer die.

The component 6 having the boss 6f on the inside as shown in FIG. 6 can be molded by the same method.

On the other hand, FIGS. 7 (a) and 7 (b) show the axial pressing and ironing directions in the case of molding a stepped component. In both cases, the end face is applied toward the corner 6r. By performing reverse ironing while applying pressure, it becomes possible to mold the component 6 without sagging in the corner portion 6r.

[0031]

As described above in detail, in the method of molding a component according to the present invention, the boss and the flange are reversed while the end faces of the component with the boss and the drum component are pressed, and the material is applied to the corner portion. Since the parts are molded by being fluidized in at least two directions, the flowed materials collide with each other at the corners and suppress sagging, so that good quality parts without sagging at the corners can be obtained. Become.

In the case of molding a part having a flange on the inner side and the outer side, the material of the inner flange flows to the corner portion of the outer flange by performing reverse ironing while pressurizing the end surface of the inner flange. Also, since there will be no overlapping defects due to excess material at the inner corners of the outer flange and sagging will not occur at the outer corners of the outer flange, finish processing to regular dimensions by cutting, etc. It is possible to obtain highly accurate parts even without them.

Further, as compared with the case where a thick-walled material is cut to manufacture a component, the number of steps can be greatly reduced, and the yield of the material is improved, which is economical, and compression by end face pressing and reverse ironing. Since it is formed, dimensional accuracy and surface roughness can be improved.

[Brief description of drawings]

FIG. 1 is a process chart showing a method of molding a component according to a first embodiment of the present invention.

FIG. 2 is a process drawing showing a method of molding a component according to the first embodiment of the present invention.

3 (a) and 3 (b) are operation explanatory views showing a molding method of a component according to the first embodiment of the present invention.

FIG. 4 is a process drawing showing the method of molding a component according to the second embodiment of the present invention.

FIG. 5 is a process drawing showing the method of molding a component according to the second embodiment of the present invention.

FIG. 6 is a sectional view in which a part with a boss molded by the method of the present invention is partially omitted.

7 (a) and 7 (b) are explanatory views in which a part of the stepped component is omitted by the method of the present invention.

FIG. 8A is a cross-sectional view of a bossed component. (B)
FIG. 4 is a cross-sectional view of a drum-shaped part with some parts omitted.

FIG. 9A is an explanatory diagram showing a multi-step drawing method.
(B) It is explanatory drawing which shows the ironing method. (C) is an explanatory view showing the Zukumi method. (D) is an explanatory view showing a reverse ironing method. (E) is an explanatory view of the overlap of the bosses and the inner corners of the flanges.

[Explanation of symbols]

 6 parts 6a inner flange 6b outer flange 6c inner corner portion 6d outer corner portion

Claims (1)

[Claims] 1. A molding method for plastically working a bossed component or a drum-shaped component, comprising pressurizing the boss end face and the flange end face of the primary-processed component in the corner direction, and at the same time, inverting and squeezing the material in at least two directions. A method of forming a part, characterized in that the part is plastically worked while suppressing the sagging of the corner part by causing the part to flow further to the corner part.