JP4073809B2 - Ball joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ball stud comprising a spherical head and a handle extending from the head, an aluminum housing in which a housing hole for rotatably housing the head of the ball stud is formed, and a housing hole of the housing. The present invention relates to a ball joint including an aluminum plug that is fixed to a housing by closing the opening and crimping the opening.
[0002]
[Prior art]
When assembling the ball joint, the ball head of the ball stud is stored in the storage hole formed in the housing, the opening of the storage hole is closed with a plug, and the opening is crimped to fix the plug to the housing. It is known from the following patent document. In this way, by closing the opening of the housing hole of the housing that houses the head of the ball stud with a plug, dust and moisture can enter the housing hole and grease can flow out of the housing hole. Can be prevented.
[0003]
[Patent Literature]
Japanese Patent Laid-Open No. 8-128438
[Problems to be solved by the invention]
Conventionally, in order to secure a sealing property between the opening of the housing accommodation hole and the plug, and to prevent intrusion of dust and moisture or outflow of grease, the housing is provided between the opening of the housing accommodation hole and the plug. Although the caulking process of the opening portion was performed after the sealer was applied, there was a problem that the number of processes increased by the amount of the sealer application process, resulting in a cost increase.
[0005]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to ensure sealing performance without requiring application of a sealer when closing an opening of a ball joint housing with a plug.
[0006]
[Means for Solving the Problems]
To achieve the above object, according to the first aspect of the present invention, a ball stud having a spherical head and a handle extending from the head, and a storage for rotatably storing the head of the ball stud. An aluminum housing having a hole formed therein and a disk-shaped aluminum plug for closing the opening of the housing housing hole, the housing hole having an annular stepped portion inside the opening; In the ball joint in which the opening is crimped inward in the radial direction, and the outer periphery of the plug is sandwiched and fixed between the crimped portion and the step, the step has the entire surface. is formed on a plane perpendicular to the axis of the receiving hole, said plug being in contact one side and the surface of the ball stud side, the housing, while being hardened by heat treatment, before Plug is hardened by different heat treatments and the housing, the hardness of the heat-treated plug is set lower than the hardness of the housing that is the heat treatment, the outer peripheral edge portion of the other side surface of said plug, said diameter to said opening A ball joint is proposed which is formed into an inclined surface that is plastically deformed by inward caulking and is in close contact with the inner surface of the caulking portion .
[0007]
According to the above configuration, when the plug for closing the opening of the ball joint housing is fixed to the housing by caulking the opening, the hardness of the aluminum plug is lower than the hardness of the aluminum housing. By heat-treating the plug , the plug is positively plastically deformed so that the outer peripheral edge of the plug becomes an inclined surface that is in close contact with the inner surface of the crimped portion during caulking , so that the gap between the opening of the housing is reduced. It is possible to obtain a high sealing performance without the need for embedding and applying a sealer, and to prevent the intrusion of dust or moisture or the outflow of grease. In particular, by adjusting the heat treatment of the aluminum plug and the housing, it is possible to obtain the optimum sealing property and the crimping strength of the crimped opening.
[0008]
The suspension arm 11 of the embodiment corresponds to the housing of the present invention, and the first opening 16 of the embodiment corresponds to the opening of the present invention.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.
[0010]
1 and 2 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a ball joint of a suspension arm, and FIG. 2 is an exploded view of the ball joint before caulking.
[0011]
As shown in FIG. 1, a ball joint 12 that pivotally supports a suspension arm 11 of an automobile on a knuckle (not shown) includes a spherical head portion 13a, a handle portion 13b that extends integrally from the head portion 13a, and the tip of the handle portion 13b. And a ball stud 13 formed of a male screw portion 13c. The periphery of the head 13 a of the ball stud 13 is covered with a synthetic resin bearing 14 having a small friction coefficient, and the head 13 a of the ball stud 13 can swing with respect to the bearing 14. The male thread portion 13c of the ball stud 13 is fastened to the knuckle with a nut. In order to lubricate the head 13a of the ball stud 13 and the sliding surface of the bearing 14, the bearing 14 is provided with a grease pocket 14a for holding grease. A storage hole 15 is formed at the tip of the suspension arm 11 constituting the housing of the present invention, and both ends of the storage hole 15 open on both surfaces of the suspension arm 11 at the first opening 16 and the second opening 17.
[0012]
As shown in FIG. 2, when assembling the ball joint 12, the male screw portion 13 c and the handle portion 13 b of the ball stud 13 are penetrated from the first opening portion 16 having a diameter larger than that of the storage hole 15 to the second opening portion 17. Thus, the bearing 14 covering the head 13 a of the ball stud 13 can be fitted into the storage hole 15. At this time, since the diameter of the second opening 17 is smaller than the diameter of the bearing 14, the bearing 14 does not drop out of the second opening 17.
[0013]
Subsequently, in a state where the disk-shaped plug 18 inserted from the first opening 16 is supported by the step portion 19 of the storage hole 15 formed inside the first opening 16, the first opening 16 is changed in diameter. The plug 18 is fixed to the first opening 16 of the suspension arm 11 as shown in FIG. Then, both ends of the boot 20 that prevent the intrusion of dust and moisture while allowing the ball stud 13 to swing are fixed to the tip of the handle portion 13 b of the ball stud 13 and the periphery of the second opening portion 17.
[0014]
Thus, by sealing the outer periphery of the plug 18 with respect to the first opening 16, dust and moisture enter the head 13 a of the ball stud 13 and the sliding surface of the bearing 14 from the first opening 16. Or the grease in the grease pocket 14a can be prevented from flowing out of the first opening 16.
[0015]
In this embodiment, in order to improve the sealing performance of the seal portion between the first opening 16 of the suspension arm 11 and the plug 18, the aluminum suspension arm 11 and the aluminum plug 18 are subjected to heat treatment, and the hardness of the plug 18 is increased. Is lower than the hardness of the suspension arm 11.
[0016]
Concrete heat treatment to be applied to the plug 18 is a solution aging (quenching) in which the plug 18 is heated to 515 ° C. to 550 ° C. in a heat treatment furnace and then water-cooled, and then natural aging is allowed to stand at room temperature for 96 hours or more. Is.
[0017]
The specific heat treatment applied to the suspension arm 11 is a solution treatment (quenching) in which the suspension arm 11 is heated to 515 ° C. to 550 ° C. in a heat treatment furnace and then cooled with water, and then heated again to 170 ° C. to 180 ° C. After 8 hours, artificial aging is performed by cooling at room temperature for about 1 hour.
[0018]
As a result of the heat treatment, the hardness of the plug 18 becomes lower than the hardness of the suspension arm 11, and an inclined surface is formed by the first opening 16 to closely contact the outer peripheral edge of the plug 18 to the inner surface of the caulking portion during caulking. actively plastically deformed so as, so to fill the gaps between them can be enhanced sealability, preventing the outflow of intrusion or grease dust and moisture to obtain a high sealing property without requiring application of sealer can do. Further, by adjusting the heat treatment of the plug 18 and the suspension arm 11, it is possible to obtain the optimum sealing performance and the optimum caulking strength of the first opening 16.
[0019]
Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.
[0020]
For example, the ball joint 12 for the suspension arm 11 has been described in the embodiment, but the present invention can be applied to a ball joint for uses other than the suspension arm.
[0021]
The heat treatment applied to the suspension arm 11 and the plug 18 is not limited to that described above, and any heat treatment may be used as long as the hardness of the plug 18 is lower than the hardness of the suspension arm 11 by the heat treatment.
[0022]
【The invention's effect】
As described above, according to the first aspect of the present invention, the ball stud having the spherical head and the handle extending from the head, and the storage hole for rotatably storing the head of the ball stud are formed. A housing made of aluminum and a disk-shaped aluminum plug that closes the opening of the housing hole of the housing, the housing hole having an annular step inside the opening, and the opening In the ball joint in which the outer peripheral portion of the plug is sandwiched and fixed between the crimped portion and the stepped portion, the stepped portion has the entire surface of the storage hole. is formed on a plane perpendicular to the axis, of the plug, are in contact one side and the surface of the ball stud side, the housing, while being hardened by heat treatment, said plug said Is hardened by different heat treatment Ujingu, hardness of the heat-treated plug is set lower than the hardness of the housing that is the heat treatment, the outer peripheral edge portion of the other side surface of said plug, said radially inward with respect to the opening Since it is plastically deformed by caulking and formed on an inclined surface that is in close contact with the inner surface of the caulking portion, the plug that closes the opening of the ball joint housing is fixed to the housing by caulking the opening. In this case, heat treatment is performed so that the hardness of the aluminum plug is lower than the hardness of the aluminum housing, so that the outer peripheral edge of the plug becomes an inclined surface that is in close contact with the inner surface of the caulking portion during caulking. as such, fills a gap between the opening of the housing actively plastically deform the plug, without the need for application of sealer It is possible to prevent the outflow of intrusion or grease dust and moisture to obtain a high sealing property. In particular, by adjusting the heat treatment of the aluminum plug and the housing, it is possible to obtain the optimum sealing property and the crimping strength of the crimped opening.
[Brief description of the drawings]
[Fig. 1] Longitudinal sectional view of the ball joint of the suspension arm [Fig. 2] Exploded view of the ball joint before caulking [Explanation of symbols]
11 Suspension arm (housing)
13 Ball stud 13a Head 13b Handle 15 Storage hole 16 First opening (opening)
18 plugs

Claims (1)

A ball stud (13) having a spherical head (13a) and a handle (13b) extending from the head (13a);
An aluminum housing (11) formed with a storage hole (15) for rotatably storing the head (13a) of the ball stud (13);
A disc-shaped aluminum plug (18) that closes the opening (16) of the housing hole (15) of the housing (11);
The storage hole (15) has an annular step (19) inside the opening (16), and the opening (16) is crimped radially inward, and the crimping portion and the step In the ball joint in which the outer peripheral part of the plug (18) is sandwiched and fixed between the part (19),
The entire surface of the step portion (19) is formed in one plane perpendicular to the axis of the storage hole (15), and is in surface contact with one side surface of the plug (18) on the ball stud (13) side. And
The housing (11) is quenched by heat treatment,
The plug (18) is quenched by a different heat treatment from the housing (11),
The hardness of the heat treated plug (18) is set lower than the hardness of the heat treated housing (11) ,
The outer peripheral edge of the other side surface of the plug (18) is formed into an inclined surface that is plastically deformed by the radially inward caulking with respect to the opening (16) and is in close contact with the inner surface of the caulking portion. A ball joint characterized by that.

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