JP2004278736A - Ball joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure sealing performance without the need for applying a sealer when blocking the opening part of a housing of a ball joint with a plug. <P>SOLUTION: The ball joint 12 pivotally supporting a suspension arm 11 on a knuckle is provided with a ball stud 13, a bearing 14 rotatably covering a head 13a of the ball stud 13, a suspension arm 11 made of aluminum, in which a storage hole 15 to store the bearing 14 is formed, and a plug 18 made of aluminum, in which an opening 16 of the storage hole 15 is blocked to lock the opening 16 by caulking. The housing 11 and the plug 18 are heat-treated, the hardness of the plug 18 is made lower than the hardness of the housing 11, and the plug 18 is positively subjected to plastic deformation at caulking so that high sealing performance is obtained without the need for applying the sealer to prevent dust and moisture from permeating or grease from flowing out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a ball stud having a spherical head and a handle extending from the head, an aluminum housing having a housing hole for rotatably housing the head of the ball stud, and a housing hole of the housing. The present invention relates to a ball joint having an aluminum plug fixed to a housing by closing an opening and caulking the opening.
[0002]
[Prior art]
When assembling the ball joint, the ball head of the ball stud is housed in the housing hole formed in the housing, the opening of the housing hole is closed with a plug, the opening is caulked, and the plug is fixed to the housing. It is known from the following patent documents. By closing the opening of the housing hole for housing the head of the ball stud with the plug as described above, dust and moisture can enter the housing hole of the housing, and grease flows out of the housing hole to the outside. Can be prevented.
[0003]
[Patent Document]
JP-A-8-128438
[Problems to be solved by the invention]
By the way, conventionally, in order to secure the sealing property between the opening of the housing hole of the housing and the plug, and to prevent the intrusion of dust or moisture or the outflow of grease, between the opening of the housing hole of the housing and the plug. The caulking process of the opening is performed after the application of the sealer. However, there is a problem that the number of processes is increased by an amount corresponding to the application process of the sealer and causes a cost increase.
[0005]
The present invention has been made in view of the above-described circumstances, and has as its object to secure sealing performance without requiring application of a sealer when closing an opening of a housing of a ball joint 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 housing for rotatably housing the head of the ball stud. A ball joint comprising: an aluminum housing having a hole formed therein; and an aluminum plug fixed to the housing by closing an opening of the housing hole of the housing and caulking the opening. A ball joint is proposed in which the plug is heat-treated so that the hardness of the plug is lower than the hardness of the housing.
[0007]
According to the above configuration, when the plug for closing the opening of the housing of the ball joint 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 during crimping to fill the gap with the opening of the housing, and a high sealing property is obtained without the need for the application of a sealer. Intrusion or grease outflow can be prevented. In particular, by adjusting the heat treatment of the aluminum plug and the housing, it is possible to obtain optimum sealing properties and 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]
BEST MODE FOR CARRYING OUT 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 one 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 crimping.
[0011]
As shown in FIG. 1, a ball joint 12 for pivotally supporting a suspension arm 11 of an automobile to a knuckle (not shown) includes a spherical head 13a, a handle 13b extending integrally from the head 13a, and a tip of the handle 13b. And a ball stud 13 formed of a male screw portion 13c formed on the ball screw. The periphery of the head 13a of the ball stud 13 is covered with a bearing 14 made of a synthetic resin having a small coefficient of friction, and the head 13a 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 housing hole 15 is formed at the tip of the suspension arm 11 constituting the housing of the present invention, and both ends of the housing hole 15 are opened 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 13 b of the ball stud 13 penetrate from the first opening 16 having a larger diameter than the storage hole 15 to the second opening 17. Thus, the bearing 14 covering the head 13a 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 fall out of the second opening 17.
[0013]
Subsequently, with the disc-shaped plug 18 inserted from the first opening 16 supported by the step 19 between the first opening 16 and the storage hole 15, the first opening 16 is directed radially inward. By caulking and pressing against the plug 18, the plug 18 is fixed to the first opening 16 of the suspension arm 11, as shown in FIG. Both ends of a boot 20 that prevents the entry of dust and moisture while allowing the ball stud 13 to swing are fixed to the tip of the handle 13 b of the ball stud 13 and the periphery of the second opening 17.
[0014]
In this way, by sealing the outer peripheral portion 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 grease in the grease pocket 14a can be prevented from flowing out of the first opening 16.
[0015]
In this embodiment, the aluminum suspension arm 11 and the aluminum plug 18 are subjected to heat treatment in order to enhance the sealing performance of the seal between the first opening 16 of the suspension arm 11 and the plug 18, and the hardness of the plug 18 is increased. Is lower than the hardness of the suspension arm 11.
[0016]
As a specific heat treatment applied to the plug 18, a solution treatment (quenching) is performed in which the plug 18 is heated to 515 ° to 550 ° in a heat treatment furnace and then water-cooled, and then natural aging is performed at room temperature for 96 hours or more. Things.
[0017]
As a specific heat treatment to be applied to the suspension arm 11, a solution treatment (quenching) of heating the suspension arm 11 to 515 ° to 550 ° in a heat treatment furnace, followed by water cooling, and then reheating to 170 ° to 180 ° is performed. After holding for 8 hours, cooling is performed at room temperature for about 1 hour to perform artificial aging.
[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 the outer peripheral portion of the plug 18 is positively plastically deformed by the first opening 16 at the time of caulking, thereby filling the gap between the two and sealing. Therefore, it is possible to obtain a high sealing property without requiring the application of a sealer and to prevent intrusion of dust and moisture or outflow of grease. Further, by adjusting the heat treatment of the plug 18 and the suspension arm 11, it is possible to obtain an optimal sealing property and an optimal caulking strength of the first opening 16.
[0019]
The embodiments of the present invention have been described above. However, various design changes can be made in the present invention without departing from the gist thereof.
[0020]
For example, in the embodiment, the ball joint 12 for the suspension arm 11 has been described. However, the present invention can be applied to a ball joint other than the suspension arm.
[0021]
The heat treatment applied to the suspension arm 11 and the plug 18 is not limited to the above-described one, and any heat treatment may be used as long as the hardness of the plug 18 becomes lower than the hardness of the suspension arm 11 due to the heat treatment.
[0022]
【The invention's effect】
According to the first aspect of the present invention, when the plug for closing the opening of the housing of the ball joint is fixed to the housing by caulking the opening, the hardness of the aluminum plug is fixed. Is heat-treated so that it is lower than the hardness of the aluminum housing, so that the plug is positively plastically deformed during caulking to fill the gap with the housing opening, eliminating the need for sealer application. It is possible to obtain a high sealing property and prevent intrusion of dust or moisture or outflow of grease. In particular, by adjusting the heat treatment of the aluminum plug and the housing, it is possible to obtain optimum sealing properties and crimping strength of the crimped opening.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a ball joint of a suspension arm. FIG. 2 is an exploded view of the ball joint before swaging.
11 Suspension arm (housing)
13 ball stud 13a head 13b handle 15 accommodation hole 16 first opening (opening)
18 plug

Claims (1)

A ball stud (13) having a spherical head (13a) and a handle (13b) extending from the head (13a);
An aluminum housing (11) having a storage hole (15) for rotatably storing the head (13a) of the ball stud (13);
An aluminum plug (18) fixed to the housing (11) by closing the opening (16) of the storage hole (15) of the housing (11) and caulking the opening (16);
In a ball joint with
A ball joint, wherein the housing (11) and the plug (18) are heat-treated so that the hardness of the plug (18) is lower than the hardness of the housing (11).

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