JPS5913540A - Forging method of housing for ball joint - Google Patents

Abstract

PURPOSE:To obtain a stud projection opening part having high strength, by geneating a burr being thicker than the tip edge of the opening inside circumferential side, in the inside circumference of the stud projection opening part, and quickening a flow of a surplus thick portion of the projection opening part, when forming the stud projection opening part of a housing. CONSTITUTION:A bottomless member A2 having a cylindrical circumferential wall 10 and a holed 12 flange-like stud projection opening part 13 in the inside circumference of one end side in the axial direction of said circumferential wall 10 is formed by forging a circular base material. Its bottomless member A2 is inserted into a cylindrical hole 42 of a die 39, and the stud projection opening part 13 of the member A2 is pressed so as to be pinched by a pair of punches 37, 40 whose axial core wire of a die cylindrical hole 42 is equalized to the axial core, whose each tip face is opposed, and whose recessed part 41 for generating a burr is formed in the center of the tip face. Therefore, a surplus thick portion of the stud projection opening part 13 moves as a burr 20 into a space by a recessed part 40 of the punch tip face, and a flow of the surplus thick portion is quickened. Accordingly, the stud projection opening part 13 is swaged sufficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is to form housings A and A4 of a ball joint 2 into a substantially completed shape by forging, as shown in FIGS. 1 and 13, which are used in automobile suspension systems. In particular, it is desired that the protruding opening 13 from which the ball stand shaft portion 5 of the Ugings A and A4 protrudes is formed by a forging method that produces a burr 20 on the inner circumferential side of the protruding opening 13 to be thicker than the tip edge 21 on the inner circumferential side of the opening. Concerning forming into a finished shape.

A ball joint 2 connected to one end of the suspension lower arm 1 shown in FIG. The housing A is held in the housing A, and the caulking portion 9 at one end in the axial direction of the housing A is bent onto the closing plate 7 to close the one end with the closing plate 7.
A ball shaft 5 is allowed to swing freely and protrude from the inner periphery of the small-diameter opening at the other end, that is, the stud protruding opening 8.

This kind of ball joint 2's No-Using A & J
Although it has traditionally been formed by forging, it has not yet been possible to form it into a nearly completed shape to size, and a considerable portion of it has been finished by cutting.

Therefore, an attempt was made to improve the molding method by carrying out the molding steps shown in FIGS. 2 to 6, but it was extremely difficult to mold the shape of the stud protruding opening I3 into the desired completed shape.

That is, as shown in FIG. 1, a desired volume of material AO is prepared, and the AO is forwardly extruded into a bottomed cylindrical shape in the first molding step as shown in FIG. As shown in Fig. 3, the bottom is punched out in the second molding step to form a punched hole J2 and a flange-shaped stud protruding opening J3 that forms the periphery of the hole, and the bottom punched member A2 is finished in the subsequent third molding step. By molding, it is possible to obtain a finished molded member A3 having the crimped portion I4 and the inner wall surface 22 of the cylindrical inner wall 10 in a desired substantially completed shape.

However, in this third molding process, the straight protruding opening 1-1 part 1
When attempting to upset the protruding portion 11 13 in the axial direction in order to form the part 3 into a substantially completed shape, as the inner diameter of the punched hole J2 becomes smaller as shown in FIG. 5, the forming resistance rapidly increases.
Even if the molding load is increased, the desired shape will not be achieved and the protrusion amount ['' portion 13
It was impossible to embed it.

Therefore, as shown in FIG. 6, the protruding opening I3 of the housing A4 had to be finished by cutting the finished molded member 113.

Note that 16. in Figure 6. The part marked by 17.18 represents the cut away part.

Moreover, the stud protruding opening]3 of the housing A4 is
In particular, the metal flow connection between the tip edge 2'1 on the inner circumferential side of the opening and the cylindrical peripheral wall 10 is also poor, and the strength tends to be slightly lowered. In this respect, the ball stud 3 of the ball joint 2 is prevented from coming off the spherical head 4 from the protruding opening j3 by the tip edge 21 on the inner peripheral side of the opening of the housing A, so that the strength of the protruding amount]3 is reduced. There is a problem.

Therefore, in the present invention, when finish forming the bottom punching member A2, an opening is formed on the inner peripheral side of the stud protruding opening 13. By generating a large thick inner peripheral bottom burr 20, the flow of excess wall of the stud protrusion opening 130 is promoted to reduce molding resistance, and it is possible to mold the stud protrusion opening 13 in a substantially completed shape.・The purpose is to provide a forging method for Uzing.

Examples of the manufacturing method according to the present invention will be described below with reference to the drawings. In addition, in FIGS. 8 to 1.0 showing the welding 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 housing A4 for the ball joint, a cylindrical rod having a desired diameter, approximately the same as the diameter of the housing A4, is cut in advance to prepare a material Ao of the required volume as shown in FIG. 7.

Then, as shown in FIG. 8, in the first molding step, the element (:AAO) is inserted into the die 31,
2, and then the punch 30 is struck against the upper surface of the material Ao to extrude it forward into a cylindrical shape with the 1AAAO bottom 11, and 1) the IJ side extrusion part A1 is formed.

Next, as shown in FIG. 9, in the second molding step, the front extrusion 1 to member A1 are inserted into the die 35 and supported by the counter punch 36, and then the upper surface of the front extrusion member A1 is pressed down with the stripper 34, and Punch out the bottom II of the front extrusion member A1 with a punch 33,
A bottom punching part 1 having a punching hole 12 and a flange-like stud protruding opening 3 forming a periphery of the hole is punched out of the member AI.
Mold into JA2.

Furthermore, in the third molding step as shown in FIG. 'Place the member A2 on the upper surface.
The stud protrusion opening 13 is pressurized by a pair of mutually opposing punches 37, 40 so as to be sandwiched therebetween, thereby forming a finished molded member A3 having a desired substantially completed shape.

A pair of punches 3 having the same axis as the die cylindrical hole 42 axis in this third molding step and having their tip surfaces facing each other.
7.40, four parts 38, 41 for forming paris, which are opposed to each other on the axis of the cylindrical hole 42 of the die 390, are recessed in the center of the front end surface.

Therefore, the flange-like stud protruding opening 1 of the section A2
3 is pressed between the pair of punches 37.40, the extra wall of the protruding opening 130 moves into the space formed by the pair of opposing four portions 38.4 for forming a paris on the tip end surface of the punch.

The extra wall after the movement is located within the space formed by the four opposing parts 38 and 41 at a height in the same direction as the height h of the inner peripheral side of the opening of the stud protruding opening 13. A Paris 20 with a large H is formed.

That is, the paris 20 generated inside the tip edge 21 on the inner peripheral side of the opening
As the excess metal moves and the inner diameter of the punched hole 12 becomes smaller, the resistance to the movement of the excess metal toward the center increases, so it moves in the axial direction where there is less resistance. Conceivable.

Finished molded member A3 subjected to such a third molding step
is the stud protrusion amount 1] The inner periphery and upper end of the portion 13 are the first
As shown on the left side of FIG. 1, it is formed into an inverted conical inner circumferential surface 8 having a desired completed shape and a flat upper end surface 9 continuing to the upper edge of the inner circumferential surface 8. And still the caulked part by the third forming process]
4 and the inner wall surface 22 of the cylindrical inner wall 10 are also finished molded into the desired substantially completed shape.

Therefore, the parts of the finished molded part A3 that require cutting are as follows:
Stud protrusion opening 1 as shown by the right side in FIG.
3 on the inner circumference, a dust cover mounting groove portion 17 on the outer circumference facing the inner circumference bar 20, and a tip portion 18 of the caulking portion 14, as in the conventional case shown in FIG. There is no need to finish cutting the inverted conical inner surface 8 and the upper end surface 9. Note that FIG. 13 shows a cross section of the housing A4 in a completed shape after cutting and finishing.

In addition, the finishing molded part (2
The flow of the axial cross section of A3 is shown in Fig. 12 and Fig. 1.
As shown in FIG. 3, in particular, the metal flow of the stud protruding opening 13 curves toward the inner circumferential edge 20, completely connecting the opening inner circumferential side tip edge 21 and the cylindrical circumferential wall 10. become. Therefore, the stud protrusion opening 13 has a high stud pull-out resistance and can provide good ball joint function.

That is, when the stud protrusion opening 13 is molded in the third molding step described above, the excess material is formed into a large inner circumferential bar with a height H.
20 and completely moved to the inner diameter side, such a good metal flow connection can be obtained.

As described above, according to the present invention, in molding the stud protrusion opening of the housing, a stud protrusion amount is generated on the inner periphery of the part that is thicker than the tip edge on the inner circumferential side of the opening, thereby suppressing the flow of the excess wall of the stud protrusion opening. As a result, it is possible to forge a stud protruding opening in a substantially completed shape with excellent strength and with a small forming force without putting any strain on the mold.

The present invention is not limited to the housing with the round window opening described above, but can also be applied to the molding of a tyrosotent ball/yoint with a long window opening, or a similar part 3 having such an opening.

[Brief explanation of drawings]

1st ell;l: A cross-sectional front view of the suspension ball. 2i to 6 are explanatory diagrams of a conventional forging method for a ball joint housing. Figures 7 to 1
FIG. 1 shows an embodiment of the present invention, and is an explanatory diagram of a forging method for a housing for a ball joint. FIGS. 12 and 13 are explanatory views showing the cross-sectional flow of the housing corresponding to FIGS. 10 and 11, respectively. (Explanation of symbols) AO...Material. A1 Anterior extrusion part month. A2... Bottoming member. A3: Finishing molding part. A4... (cutting processed part) housing. A.-Housing. 8... Inverted conical inner peripheral surface. 9...Tip surface. 1o.-Cylindrical peripheral wall. 11... Bottom. 12-...Hit one friend hole. ]3 Stud protrusion opening. 20- Inner circumference notch. 21...Open [Inner circumference, but 1j tip edge. 37・-Pa) Ch. 38...concave sound μ039
−・ Dice. 40・-Idol no ζinch. 41... Concave part. 42... Tie-sli cylindrical JL. Patent applicant Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A cylindrical element @AO is forged to form a bottom punching member A2 having a cylindrical circumferential wall 10 and a flange-shaped stud protruding opening 13 with a hole 12 on the inner periphery of the cylindrical circumferential wall at one end in the axial direction. Insert the bottomed sounding material A2 into the cylindrical hole 42 of the die 39, and align the flange-shaped stud protruding opening 13 of the member A2 with the axis of the die cylindrical hole 42. The tip surfaces face each other and there is a recess 3 in the center of at least one tip surface for generating a saw.
A pair of 7% inches 37,4' formed by 8(4,1,)
Pressure is applied so that the stud protruding opening 130 in the form of a flange is moved as a slot 20 into the space formed by the recess 38 (40) on the tip end surface of the /N inch. A method for forging a uzing for a ball joint nod, which is characterized by promoting the □flow of meat, thereby sufficiently upsetting the stud protruding opening 13, and forming the stud protruding opening 13 into a desired completed shape. .