JPH09323137A - Method for cold-forging of housing with shank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the formation of a product in a good precision without developing the defect, such as underfill, crack, in the product by forming an intermediate forged product having a specific shape, pressurizing an intermediate shank, tapered part and intermediate columnar body and simultaneously forming a shank, step part and cuplike body. SOLUTION: A columnar blank 1 having almost the same vol. as the vol. of a desired housing 51 with the shank, is formed and successively, deep-drawing is applied at the one end part of the columnar blank 1 to form a preliminary forged product 11 having a preliminary columnar body 12 and a preliminary shank 16 of the smaller diameter than that of the preliminary columnar body 12. Successively, the preliminary columnar body 12 of the preliminary forged product 11 is pressed in the axial direction and the disk-like intermediate columnar body 22 having the tapered part 26 of gradually smaller diameter over from the intermediate columnar body 22 to the intermediate shank 26 near the outer periphery of side end surface of the intermediate shank 26, is formed to form the intermediate forged product 21. Then, finally, the A intermediate forged product 21 is pressurized to form the housing 51 with the shank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold forging method for a handle housing used in, for example, a ball joint.

[0002]

2. Description of the Related Art Cold forging is a processing method for producing a product having a predetermined shape by applying pressure to a metal material with a punch and extruding or filling the metal material along a shape of a mold at room temperature or below the recrystallization temperature of the material. It has the advantages of improved mechanical properties and mass production with product accuracy comparable to cutting, but it has a higher deformation resistance than hot forging, and the accuracy decreases when the product shape becomes complicated. is there.

Conventionally, when the handle-equipped housing 151 shown in FIGS. 1 to 3 is formed, it is formed by a forging step shown in FIG. That is, one end of the columnar material 101 ((A) in FIG. 6) having substantially the same volume as the desired volume of the housing 151 with a handle is subjected to a drawing process to have a diameter smaller than that of the preliminary cylindrical body 112 and the preliminary cylindrical body 112. Reserve pattern 116
A pre-forged product 111 (FIG. 6 (A)) having the following is formed, and then the pre-cylindrical main body 112 of the pre-forged product 111 is pressed in the axial direction to form the disc-shaped post-shaped main body 122 and the pre-handle 116. A first intermediate forged product 121 ((C) in FIG. 6) having an intermediate handle 126 of the same shape is formed. Next, the cylindrical main body 122 of the first intermediate forged product 121 is subjected to a drawing process, and an intermediate step portion 134 having an intermediate cutout 135 is formed between the cylindrical main body 122 and the intermediate handle 126 at intervals on the outer circumference. The second intermediate forged product 131 ((D) in FIG. 6) was formed, and subsequently the cylindrical main body 122 of the second intermediate forged product 131 was subjected to backward extrusion to form a cup-shaped cup-shaped main body 142. A three intermediate forged product 141 ((e) in FIG. 6) is formed, and finally, the outer periphery of the cup-shaped body 142 of the third intermediate forged product 141 is subjected to drawing to form two parallel pairs of spanner hooking surfaces 153. At the same time, the whole was subjected to sizing to form a housing 151 with a handle ((f) in FIG. 6).

[0004]

According to the cold forging method as described above, since the forming process is divided into a plurality of times and the amount of forming in one time is reduced, the housing 151 with a handle can be accurately formed. However, the handle housing 151
Since the number of molding steps is increased in order to improve the accuracy of, the molding time may increase and the productivity may decrease.

Therefore, it is conceivable to reduce the number of steps and improve the productivity. However, if the number of processes is reduced, the amount of molding once must be increased.
When forming a complicated shape like 51 by cold forging,
There are cases where defects such as lack of meat and cracks occur in the product.

Accordingly, the present invention solves the above-mentioned problems,
An object of the present invention is to provide a cold forging method for a patterned housing, which is highly accurate and has high productivity without causing defects such as wall thinning and cracking in the product.

[0007]

The present invention is as follows.

A first step of forming a columnar material having a volume substantially the same as that of a desired housing with a handle, a stepwise cold forging process performed on the columnar material, and an intermediate handle having a substantially same shape as the handle.
An intermediate columnar body having substantially the same outer diameter as the cup-shaped body, and between the intermediate handle and the intermediate columnar body, the diameter gradually decreases from the outer circumference of the intermediate columnar body, and the minimum diameter is the minimum step diameter. Second step of forming an intermediate forged product consisting of a taper portion set between the outer diameter of the spanner hanging surface and the intermediate handle, taper portion and intermediate cylindrical main body of the intermediate forged product are pressed, and the handle and stepped portion are formed. And a third step of simultaneously molding the cup-shaped body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

1 to 3 show a handle housing 51 formed by the cold forging method of the present invention, and two pairs of parallel spanner hooking surfaces 53 for engaging a spanner on the outer periphery.
And a step of forming a cup-shaped cup-shaped main body 52 in which is formed, and a cutout portion 55 formed continuously from a bottom portion 52a of the cup-shaped main body 52 at an outer periphery with a not-shown detent plate bent and engaged. It is composed of a portion 54 and a handle 56 which is continuously formed from the step portion 54 by extending in the axial direction. A male screw is formed on the handle 56 by a subsequent rolling process.

A method of cold forging the above-mentioned handle housing 51 will be described with reference to FIG.

First, a columnar material 1 (FIG. 4A) having substantially the same volume as the desired housing 51 with a handle is formed, and then one end of the columnar material 1 is subjected to a drawing process to prepare a preliminary circle. Pre-forged product 11 having a columnar main body 12 and a preliminary handle 16 having a diameter smaller than that of the columnar main body 12 ((a) in FIG. 4)
To form Next, the preliminary cylindrical body 12 of the preliminary forged product 11
Is pressed in the axial direction, and the intermediate handle 26 (same as the spare handle 16)
Near the outer periphery of the side end surface, the intermediate cylindrical body 22 to the intermediate handle 26
The intermediate forged product 21 ((c) in FIG. 4) is formed by molding the disk-shaped intermediate cylindrical main body 22 having the taper portion 29 having a gradually decreasing diameter. Here, the minimum diameter r1 of the tapered portion 29 of the intermediate forged product 21 is the desired housing 5 with handle.
It is set between the minimum diameter r2 of the step portion 54 of 1 ((d) in FIG. 4) and the outer diameter r3 of the spanner hanging surface 53. Finally, the intermediate forged product 21 is pressed to form the handle housing 51.

The process of forming the handle housing 51 from the intermediate forged product 21 will be described with reference to FIG.

Reference numeral 61 is a forging device, which comprises an upper die 71 and a lower die 81.

The upper die 71 has a punch 72 along its axis.
Is arranged, and the tip of the punch 72 is a housing 51 with a handle.
The punch forming portion 72a has the same shape as the inner peripheral shape of the cup-shaped main body 52. A ring-shaped punch guide 73 is arranged on the outer peripheral side of the punch 72.
A backup ring 74 is disposed above the. Reference numeral 75 denotes an upper guide that integrally holds the punch 72, the punch guide 73, and the backup ring 74.

The lower die 81 is provided with a die 82 having a die engraving space 83 having the same shape as the outer peripheral shape of the handle housing 51, facing the punch 72. The die engraving space is arranged along the axis of the die 82. A through hole 84 communicating with 83 is formed. Under the die 82, a base 85 is provided.
Is formed with a through-hole 86 that is continuous with the through-hole 84 of the die 82, and a knockout pin 87 that can move up and down in the up-down direction is disposed in the through-holes 84 and 86. And 88 is die 8
This is a lower guide that holds the base 2 and the base 85 together.

With the forging device 61, the housing 51 with a handle is provided.
5 is formed, as shown in the left half of FIG. 5, the intermediate forged product 21 is put into the die engraving space 83 of the lower die 81 with the upper die 71 standing by above, and then the right half of FIG. As shown, the upper mold 71 is lowered. At this time, the punch 72 is guided to the inner circumference of the lower die 81 together with the punch guide 73, and the die engraving space 83
Then, the intermediate forged product 21 is pressure-molded into the housing 51 with a handle. Here, since the minimum diameter r1 of the tapered portion 29 of the intermediate forged product 21 is set between the step portion 54 minimum diameter r2 and the spanner hanging surface 53 outer diameter r3,
The cup-shaped main body 52 having the step portion 54 having the cutout portion 55 and the spanner hanging surface 53 is formed along the tapered portion 29. After the molding, the upper mold 71 retracts upward, the knockout pin 87 projects upward, and the molded handle housing 51 is taken out from the lower mold 81 and the molding is completed.

Therefore, the stepped portion 54 and the cup-shaped main body 52 of the handle housing 51 having the complicated shape are formed into the intermediate forged product 2.
Since the molding is performed along the tapered portion 29 of No. 1, the product is free from flesh thickness, cracks, and the like.

In the above embodiment, the housing 5 with a handle is provided.
Although 1 is formed from the cup-shaped main body 52, the stepped portion 54 and the handle 56, it may have a multi-stepped shape.

Further, it is desirable that the angle of the tapered portion 29 of the intermediate forged product 21 is changed according to the outer peripheral shape of the handle housing 51.

[0021]

As described above, according to the present invention, the first step of forming a columnar material having substantially the same volume as the volume of the desired housing with handle, and the step of cold forging the columnar material, It is formed between the intermediate handle having the same shape as the handle, the intermediate columnar body having the same outer diameter as the cup-shaped body, and the intermediate handle and the intermediate columnar body, and the diameter gradually decreases from the outer periphery of the intermediate columnar body. , A second step of forming an intermediate forged product having a taper portion whose minimum diameter is set between the step portion minimum diameter and the spanner hanging surface outer diameter, and an intermediate handle, taper portion and intermediate circle of the intermediate forged product. Since it consists of the third step of pressurizing the columnar body and simultaneously molding the handle, step and cup-shaped body, the handle housing is molded along the tapered part of the intermediate forged product, so the product lacks or cracks. It is possible to mold with high accuracy without causing problems. Moreover, since the number of molding steps is small, high productivity can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a housing with a handle.

FIG. 2 is a plan view showing a housing with a handle.

FIG. 3 is a cross-sectional front view showing a housing with a handle.

FIG. 4 is a sectional front view showing a cold forging method for a housing with a handle according to an embodiment of the present invention.

FIG. 5 is a sectional front view showing a cold forging method for a handle housing according to an embodiment of the present invention, particularly showing a step of forming a handle housing from an intermediate forged product, in which the left half portion is before forming;
The right half is a sectional front view showing a state after molding.

FIG. 6 is a cross-sectional front view showing a conventional cold forging method for a housing with a handle.

[Explanation of symbols]

 1 Cylindrical material 21 Intermediate forged product 22 Intermediate columnar body 26 Intermediate handle 29 Tapered portion 51 Handled housing 52 Cup-shaped body 52a Bottom portion 53 Spanner hanging surface 54 Step portion 55 Notched portion 56 Handle r1 (Tapered portion) Minimum diameter r2 ( Step) Minimum diameter r3 (Spanner hanging surface) Outer diameter

Claims (1)

[Claims] 1. A cup-shaped body (52) in which a spanner hanging surface (53) parallel to the outer periphery is formed, and the cup-shaped body (5).
A step portion (54) in which a cutout portion (55) is formed continuously from the bottom portion (52a) of FIG.
4) A handle (56) continuously formed in the axial direction by molding.
In a cold forging method of a patterned housing having and,
First, a first step of forming a columnar material (1) having substantially the same volume as the desired volume of the housing (51) with a handle and a stepwise cold forging process of the columnar material (1) are performed to form a handle (5).
6) an intermediate handle (26) having substantially the same shape, an intermediate columnar body (22) having an outer diameter substantially the same as the cup-shaped body (52), the intermediate handle (26) and the intermediate columnar body (22). Between the outer circumference of the intermediate columnar main body (22) formed gradually, the diameter gradually decreases, and the minimum diameter (r1) is the minimum diameter (r) of the step portion (54).
2) and an intermediate forged product (21) consisting of a taper portion (29) set between the spanner hanging surface (53) outer diameter (r3)
And a second step of forming the intermediate forging (21), the intermediate handle (26), the taper portion (29) and the intermediate cylindrical body (2).
A cold forging method for a housing with handle, comprising a third step of pressurizing 2) and simultaneously molding the handle (56), the step (54) and the cup-shaped body (52).