JP2791627B2 - Cold forging method for flanged housing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cold-forging a flanged housing used for a ball joint or the like used in an automobile suspension system or a steering system.

[0002]

2. Description of the Related Art Conventionally, as a cold forging method of a flanged housing, there is a method as shown in FIGS.

First, in a first step, a cylindrical material W100 obtained by cutting a round bar material to a required length is placed in a cylindrical wall portion 11.
6 and a cup-shaped intermediate cup coarse material W composed of a bottom 115
In the second step, the housing W102 having the flange 111 is formed by inserting the end of the intermediate cup coarse material W101 on the opening 113 side.

Further, as another cold forging method, there is a method as shown in FIGS. 5A to 5C.

[0005] That is, in the first step, a cylindrical column material W200 obtained by cutting a round bar material to a required length is put into a cylindrical wall portion 21.
6 and a bottom portion 215, and is formed into an intermediate flanged coarse material W201 having a peripheral spare flange portion 218 extending in the axial direction from the front end thereof on the outer periphery of the opening 213. In the second step, the intermediate flanged coarse material W201 is formed.
The housing W202 having the desired flange portion 211 was formed by cutting the outer peripheral end portion of the spare flange portion 218 of 201 into a circumferential shape by machining.

[0006]

In the cold forging method of the flanged housing as described above, as shown in FIG. 4, the flanged housing W102 is formed by inserting the end of the intermediate cup coarse material W101 on the opening 113 side. Since the flange 111 is forcibly formed by the punch and the upper and lower molds, the flange 11
1 Metal flow from the inner circumference toward the outside occurs,
As shown in FIG. 4C, there is a problem that a circumferential recess 117 is formed on the inner peripheral surface of the flange 111.

[0007] As shown in FIG.
When the first spare flange portion 218 is circumferentially cut by machining to form the flanged housing W202, there is a problem that the yield decreases as much as the cut and separated portion. Furthermore, when the flange is cut and formed, the metal flow is cut off at the cut surface, so that there is a problem that the strength is reduced.

Accordingly, an object of the present invention is to provide a cold forging method for a flanged housing which has a good metal flow in a housing including a flange portion, is free from dents, has high quality, and has a high yield.

When the flanged housing is formed by warm or hot forging, the flanged housing can be easily formed from a columnar material, but the precision as a product is poor and finishing cutting is required. Also, in terms of cost, the heating equipment for the material and the cost of heating it may increase,
This time, we invent a method of forming a flanged housing by cold forging.

[0010]

Means for Solving the Problems In a first step, a columnar cylindrical material obtained by cutting a round bar material to a required length is provided with a circumferential flange portion on one end end outer periphery and a floor portion on an axially middle inner periphery. In the second step, the floor portion of the intermediate coarse material is pressed in the opening direction on the side opposite to the flange portion to form a cup-shaped flanged housing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3 showing the forging device in the molding process of the flanged housing, the left half of each figure represents a state before molding, and the right half represents a state after molding.

FIG. 1 shows a cold forging process of a flanged housing according to an embodiment of the present invention. First, a round bar material whose diameter is approximately the same as the desired diameter of the flanged housing W2 (excluding the flange portion 11) is cut in advance to a required length, and a cylindrical material W of a required volume is cut.
Prepare 0. Then, in a first step, the column material W0 is provided with a peripheral flange portion 11 on one end end outer periphery and a floor portion 12 on an axially intermediate inner periphery by punching and closed die forging of the upper and lower molds, and openings 13 at both ends. 14 is formed into an intermediate coarse material W1. Subsequently, in a second step, the floor portion 12 of the intermediate coarse material W1 is punched.
Is pressed in the opening direction on the side opposite to the flange portion to form a cup-shaped flanged housing W2.

The step of cold forging the flanged housing will be described in more detail.

FIG. 2 shows a forging device 31 for forming the intermediate coarse material W1 in the first step. The configuration of this device will be described with reference to the drawings. Reference numeral 33 denotes a punch, which has a front end portion having substantially the same shape as the shape of the one end opening 13 of the intermediate coarse material W1 to be formed. Reference numeral 34 denotes an upper die, and a through hole 38 formed at the center inserts and holds the punch 33 so as to be movable in the vertical direction, and an upper holder 37 located on the outer periphery.
Supported by Above the upper die 34, a spacer 35 having a plurality of holding holes 40 in the circumferential direction and a spring material 36 fitted in the holding holes 40, and an upper support plate 39 for regulating the upper end of the spring material 36 are arranged. . 42 is a knockout pin,
The intermediate coarse material W1 to be formed has a tip portion having substantially the same shape as the shape of the other end opening 14 side. Reference numeral 43 denotes a lower die, and a through hole 47 formed in the center inserts and holds the knockout pin 42 so as to be movable in the vertical direction, and is supported by a lower holder 46 located on the outer periphery. Above the knockout pin 42, a lower engraving space 48 is defined by the lower die 43. Below the lower die 43, an elastic member 44 having elasticity and a lower support plate 45 for regulating the lower end of the elastic member 44 are arranged.

When forming the intermediate coarse material W1 with the forging device 31 having the above-described configuration, first, as shown in the left half of FIG.
Then, the upper die 32 is lowered integrally with the punch 33, so that the upper die 32 is held between the upper die 34 and the lower die 43, and at the same time, the molding of the cylindrical raw material W0 is started. As the molding proceeds, the elastic member 44 disposed below the lower die 43 is crushed, and the lower die 43 relatively moves downward, and the tip of the knockout pin 42 projects upward. Further, the spring material 3 disposed above the upper die 34
6 is compressed and the upper die 34 is moved to the lower end of the spacer 35.
Moves relatively upward, and the tip of the punch 33 projects downward. The projection of the punch 33 is finally performed in a closed state, and as shown in the right half of FIG.
Mold 1. Thereafter, the punch 33 and the upper die 32 are raised to a predetermined position, and then the intermediate coarse material W1 formed by the knockout pin 42 is extruded upward and taken out.

Next, a second step of forming the flanged housing will be described. FIG. 3 shows a forging device for forming a flanged housing. The configuration of this apparatus will be described with reference to the drawings. Reference numeral 53 denotes a punch, which has a tip portion having substantially the same shape as the shape of the opening 13 of the flanged housing W2 to be formed. Reference numeral 54 denotes an upper die, and a through hole 55 formed at the center inserts and holds the punch 53 integrally. Reference numeral 63 denotes a lower die, and a through hole 64 formed at the center inserts and holds the knockout pin 62 so as to be vertically movable. Above the knockout pin 62, a lower die 63 defines an engraving space 65.

With the forging device having the above structure, a flanged housing W2
In the case of forming a mold, first, as shown in the left half of FIG.
5, the intermediate coarse material W1 is inserted, and then the upper die 54 is lowered integrally with the punch 53. Then, the tip of the punch 53 comes into contact with the floor portion 12 of the intermediate coarse material W1 and at the same time, is extruded in the opening direction on the side opposite to the flange portion, thereby forming a cup-shaped flanged housing W2 as shown in the right half of FIG. Thereafter, the punch 53 and the upper die 54 are raised to a predetermined position, and then the flanged housing W2 formed by the knockout pin 62 is pushed upward and taken out.

Therefore, according to the embodiment of the present invention, a good flanged housing W2 can be formed only by cold forging without breaking the metal flow.

In the embodiment of the present invention, the flanged housing W
2 was formed in two steps, but may be formed in two or more steps by adding preforming.

[0020]

As described above, according to the present invention, a cylindrical material obtained by cutting a round bar material to a required length in the first step is obtained by:
A peripheral flange is provided on the outer periphery of one end, a floor is provided on the inner periphery in the axial direction, and formed into an intermediate coarse material having openings at both ends. In the second step, the floor of the intermediate coarse material is formed on the side opposite to the flange. Since it is pressed in the opening direction and molded into a cup-shaped flanged housing, a good and high-quality flanged housing can be molded without breaking the metal flow. Further, since the molding is performed only by the cold forging, the yield may be good.

[Brief description of the drawings]

FIG. 1 is a process diagram showing a cold forging process of a flanged housing in an embodiment of the present invention.

FIG. 2 is a sectional plan view showing a forging apparatus for forming an intermediate coarse material according to an embodiment of the present invention, in which a left half portion is before forming and a right half portion is after forming.

FIG. 3 is a cross-sectional plan view illustrating a forging device for forming a flanged housing according to an embodiment of the present invention, in which a left half portion is before forming and a right half portion is after forming.

FIG. 4 is a process diagram showing a conventional cold forging process of a flanged housing.

FIG. 5 is a process diagram showing a cold forging process of another conventional flanged housing.

[Explanation of symbols]

 11 Flange part 12 Floor part 13 Opening 14 Opening W0 Column material W1 Intermediate coarse material W2 Flanged housing

Claims (1)

(57) [Claims] 1. A cylindrical material (W0) obtained by cutting a round bar material to a required length in a first step is provided with a circumferential flange (11) on one end end outer circumference and an axial inner middle circumference. An intermediate coarse material (W1) having a floor (12) and having openings (13) and (14) at both ends is formed. In a second step, the floor (12) of the intermediate coarse material (W1) is removed. A cold forging method for a flanged housing, characterized in that the housing is pressed in the direction of an opening on the flange side to form a cup-shaped flanged housing (W2).