JPH02160138A - Forged forming method for housing for ball joint - Google Patents

Abstract

PURPOSE:To execute forged forming to a housing for ball joint being excellent in strength by forming a columnar raw material obtained by cutting a round axial material to necessary length, to a cup-like raw material, and thereafter, forming it to an expanded open raw material having a large opening part whose opening part is brought to diameter expansion. CONSTITUTION:A round bar-stock 1 having the same diameter as that of a ball joint use housing 41 is formed to a cup-like raw material 11 by extrusion forming by a punch. Subsequently, from this raw material 11, an expanded open raw material 21 having a large opening part 22 is formed by a punch in which the tip lower part 54 is brought to diameter expansion to an intermediate large diameter part 55. Subsequently, by blanking a bottom part 23 of the expanded open raw material 21 by a columnar blanking punch, a cylindrical raw material 31 having a blanking hole 33 and a flange-like small opening part 34 is formed. From this material, the housing 41 having a stepwise inside diameter edge part 44 continued from an annular collar part 45 and the inside diameter surface 43 of a large opening part 42 is forged and formed by a punch 73 whose tip part 74 has the same diameter as that of the raw material 31 and which has a large diameter intermediate part 75, and the upper die 77 of its periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forging the housing of a ball joint used, for example, in an automobile steering system and suspension system.

[Conventional technology]

Conventionally, a ball joint housing as shown in FIG. 6(D) has been produced as shown in FIG. 6(A) to FIG. 6(D) as a forging method.

That is, in the first step, nine pieces of material are cut to the required length, and a cylindrical cylindrical material 101 (FIG. 6 (a)) is cut into a cup-shaped cup-shaped raw material 111 (FIG. 6 (b)). form into a second
In the process, the bottom l1 of the cup-shaped rough material 111 is punched out.
3. Cylindrical rough material 131 punched approximately at the center ((c) in Fig. 6)
), and then in the third step, the large opening 132 of the cylindrical rough material 1810 is upset to form an annular flange that protrudes circumferentially from the outer diameter part near the large opening 142. 1
45, and a stepped inner diameter edge 144 that is continuous with the inner diameter surface 143 of the large opening 142.

[Problem to be solved by the invention]

In the forging method for a ball joint housing as described above, a cylindrical rough material 1 as shown in (/S) in FIG.
When the large opening 132 of 31 is upset and formed into a nozzle 141 having an annular flange 145 and a stepped inner diameter edge 144 as shown in FIG. 6(d), the flange 145
is forcibly formed by the punch and the upper and lower molding dies, metal flow occurs inward from the outer periphery of the large opening 142, as shown in FIG.
There is a problem in that an annular recess 147 is formed in 6.

Furthermore, the metal flow is poorly coupled at the stepped inner diameter edge 144, and the strength tends to decrease.

Therefore, when assembling the ball joint, the inner diameter edge 144 is covered with the closing plate and fixed by caulking, but the inner diameter edge 144 is damaged due to the tensile load applied to the pole joint, causing play in the closing plate. There is a problem.

Furthermore, since the molding is forced, there is a problem that the life of the punch and the upper and lower molds is shortened.

Therefore, the present invention provides an annular flange 45 and a stepped inner diameter edge 44.
The object of the present invention is to provide a method for forging a housing for a pole joint, which has a housing 410 with good metal flow and good durability between the punch and the upper and lower molds.

Structure of the invention [Means for solving the problem] A cylindrical raw material obtained by cutting a round shaft material to a required length is formed into a cup-shaped raw material, and then an opening of the cup-shaped raw material is formed. 0 [Embodiments and Effects] Examples of the present invention will be described below with reference to the drawings.

Note that in FIGS. 2 and 8 showing the forging apparatus in the main steps of the housing forming process, the left half of each figure shows the state before forging, and the right half shows the state after forging.

When forging the pole joint housing 41, a round bar material whose diameter is between the desired diameter of the housing 41 and the groove is cut to the required length, and the cylindrical material 1 of the required volume (( b))). First, in the first step, the cylindrical material 1 is formed into a cup-shaped cup-shaped raw material 11 ((b) in FIG. 1) by backward extrusion molding using a punch (not shown). Next, in a second step, the cup-shaped rough material 11 is punched with a lower tip portion 54 having approximately the same diameter as the cup-shaped rough material 11 and an intermediate large diameter portion 55 that is continuous with the lower tip portion 54 and has a large diameter. 53, an enlarged opening rough material 21 (FIG. 1(c)) with an enlarged diameter opening is formed. Subsequently, in a third step, the bottom part 28 of the expanded opening material 21 is punched out using a cylindrical punch (not shown) to form a punch hole 38 from which the shaft of the pole stud will protrude, and the area around the punch hole 33. Flange-shaped small opening 3 to be formed
4 and cylindrical rough material 8i Fig. 1/7? (d) ) is formed. Furthermore, in the fourth step, the cylindrical rough material 31 is passed through a punch 73 having an intermediate large-diameter portion 75 whose lower tip portion 74 has approximately the same diameter as the cylindrical rough material 31 and which is continuous to the lower tip portion 74 and has a larger diameter. An annular flange 4 that protrudes circumferentially from an outer diameter portion near the large opening 42 to the outside is formed by an upper die 77 that is positioned around the punch 73 and moves up and down integrally with the punch 73.
5, and a housing 41 having a stepped inner diameter edge 44 that is continuous with the inner diameter surface 43 of the large opening 42 is molded.

Among the above-mentioned housing molding steps, the second step and the fourth step, which are the key points of the present invention, will be further explained.

FIG. 2 shows an apparatus for forming the wide-opening rough material 21 in the second step.

The configuration of this device will be explained based on the drawings. Reference numeral 53 denotes a punch, which has a lower end portion 54 having approximately the same diameter as the cup-shaped raw material 11, and an intermediate large diameter portion that is continuous with the lower end portion 54 and above. It consists of a diameter portion 55 and an upper large diameter portion 56 which is continuous with the intermediate large diameter portion 55 and has an even larger diameter.

An upper die 58 fixes the punch 53 and is held by an upper substrate 57 located above. Further, the upper substrate 57 is fixed by an upper holder (not shown).

Further, 59 is a lower die, which is provided with a cylindrical hole 62 for receiving the cup-shaped rough material 11, and is provided with a stepped portion 63 and a counter hole 64 continuously below the cylindrical hole 62. A counter bunch 61 is fitted in the. Also,
The upper part of the cylindrical hole 62 is provided with an enlarged diameter hole part 65 whose diameter is enlarged. A lower substrate 60 fixes the lower die 59 and is fixed by a lower holder (not shown).

When forming the expanded opening rough material 21 with the forging device having the above configuration,
First, as shown in the left half of FIG. 2, the cup-shaped rough material 11 is inserted into the cylindrical hole 62 and supported by the upper end surface of the counter punch 61 and the stepped portion 63 of the lower die 59.

Next, as shown in FIG. 2, the punch 53 is inserted into the upper die 5.
The cup-shaped rough material 11 is lowered integrally with the lower die 59 and the intermediate large diameter portion 55 of the punch 53.
The diameter of the large opening 12 is expanded to form a desired expanded opening rough material 21.

Thereafter, the punch 53 rises to a predetermined position, and then the expanded opening rough material 21 formed by the counter bunch 61 is pushed upward and taken out.

FIG. 3 shows an apparatus for molding the housing 41 in the fourth step. To explain the configuration of this device based on the drawings, 73 is a punch, which has a lower tip portion 74 having approximately the same diameter as the cylindrical rough material 31, and an intermediate large diameter portion that continues upward from the lower tip portion 74 and has a large diameter. 75, and an upper large diameter portion 76 which is continuous with the intermediate large diameter portion 75 and has an even larger diameter. 77 is the upper die and the punch 73
The lower part of the upper die 77 is provided with a lower molding surface 84 for molding a desired flange 45 into the large opening 32 of the cylindrical rough material 31. A die holder 78 and a punch holder 79 both fix the punch 73 and the upper die 77. 8
0 holds a punch holder 79 on the upper substrate and is fixed by an upper holder (not shown).

A lower die 81 is provided with a cylindrical hole 85 for receiving the cylindrical rough material 31, and a stepped portion 86. A counter hole 87 is provided, and a counter bunch 83 is fitted into the counter hole. A lower substrate 82 fixes the lower die, and is fixed by a lower holder (not shown).

When forming the housing 41 with the forging device having the above configuration,
First, the cylindrical rough material 3 is inserted into the cylindrical hole 85 as shown in the left half of FIG.
1 and the upper end surface of the counter bunch 83 and the lower die 8.
It is supported by the step part 86 of 1.

Then, as shown in Fig. 3, the punch 73 is inserted into the upper die 7.
7 and the upper molding surface 88 of the lower die 81.
An annular flange portion 45 that protrudes circumferentially from the outer diameter portion near the large opening 42 between the intermediate large diameter portion 75 of the punch 78 and the lower molding surface 84 of the upper die 77. Then, a step-like inner diameter edge 44 is formed continuously with the inner diameter surface 43 of the large opening 42, thereby completing the desired housing 41.

In addition, in the above example, the four steps from forming the cylindrical material l to the housing 41 are one more step than the three steps in the conventional example, but since these four steps are continuous flow steps, productivity is reduced. There's nothing to do.

In addition, as another example, from the cylindrical material 1 to the cup-shaped material 1
The two steps of forming the 1° expanded opening rough material 21 may be performed in one step, and the entire process may be performed in three steps (FIG. 7).

As a function of the above embodiment, after the diameter of the large opening is expanded in advance, an annular flange 45 that protrudes circumferentially from the outer diameter part near the large opening and an inner diameter of the large opening are formed. Surface 43
Since the step-like inner diameter edge is formed continuously, the metal flow of the large opening 42 of the housing 410 is improved compared to the conventional case, as shown in FIG. Further, the molding pressure applied to the molding punch 73 and the upper die 77 is reduced.

〔effect〕

As described above, according to the present invention, since the metal flow near the large opening of the housing is improved, an annular concave ring is not formed on the outer surface of the flange, and furthermore, the stepped inner diameter edge A housing can be molded without any loss in strength. Furthermore, since the molding pressure applied to the molding punch and the upper and lower dies is reduced, there is also the effect that the life of the punch and the upper die is improved.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing the forging process of a housing for ball sealing in one embodiment of the present invention. FIG. 2 is a plan sectional view of a forging device for forming (c) in FIG. 1. FIG. 3 is a plan sectional view of a forging device for forming (e) in FIG. 1. FIG. 4 is an enlarged view of section 8 in (e) of FIG. FIG. 5 is a process diagram showing a forging process for a ball joint housing according to another embodiment of the present invention. FIG. 6 is a process diagram showing a conventional forging process of a bousing for a ball joint. FIG. 7 is an enlarged view of the T portion in (d) of FIG. 6. (Explanation of symbols) 1...Cylinder material. 11...Cup-shaped rough material. 21... Expanded opening rough material. 22, 32.42... Large opening. 23... Bottom. 31・・・・・
Cylindrical material. 41...Housing. 43...-... inside
Diameter surface. 44...--Inner diameter edge. 45-・・・Tsuba
Department. Figure 2 (A) (B) (I Figure 1 Figure 1 813A 4th evil (A) (C)

Claims (1)

[Claims] In the first step, the cylindrical column material 1 obtained by cutting the round shaft material to the required length is formed into a cup-shaped cup-shaped material 11, and then in the second step, the opening of the cup-shaped material 11 is It is formed into an expanded opening material 21 having an enlarged large opening 22, and then in a third step, the bottom part 2 of the expanded opening material 21 is formed with a punch.
3. Formed into a cylindrical rough material 31 punched approximately at the center, and then in a fourth step, the enlarged large opening 32 of the cylindrical rough material 31 is upset, and the outside diameter part near the large opening 42 is formed. An annular flange 45 that protrudes circumferentially toward the side, and a large opening 42.
1. A method for forging a housing for a ball joint, the method comprising forming a housing 41 having a step-like inner diameter edge 44 that is continuous with an inner diameter surface 43 of the housing.