JP2011158028A - Method for manufacturing ball joint device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball joint link attaining reductions in weight, cost and torque while securing rigidity and strength. <P>SOLUTION: A ball part 41 and a ball seat 17 are assembled to a socket 16. An arm part 12 is then welded in a position where the spherical center of the ball part 41 coincides with an axis C2, on the outer peripheral surface of the socket 16. Since a thinner and hollow member can be used as the arm part 12, the weight can be reduced while securing rigidity and strength. The cost can be reduced because of not requiring a complicated manufacturing process, and torque can be reduced because a bearing pressure to the ball part 41 of the ball seat 17 can be reduced by the welding heat of the arm part 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a ball joint device including an arm portion having an end portion connected to an outer peripheral surface of a socket of a ball joint.

  Conventionally, for example, this type of ball joint device used for a stabilizer link for connecting left and right suspension arms and a stabilizer for preventing the inclination of a vehicle body, that is, a roll prevention ball joint device, has been designed to improve the buckling strength. There is known a configuration in which the center (ball center) and the axis of the arm portion coincide with each other (see, for example, Patent Document 1).

  However, in this configuration, the arm portion is deformed by deforming a portion protruding from the bottomed cylindrical housing portion into which the ball portion of the ball stud and the ball seat which is a bearing seat for slidably holding the ball portion are press-fitted. Therefore, there is a problem that the manufacturing takes time and the manufacturing cost increases.

  On the other hand, a configuration is also known in which the arm portion is welded to the outer peripheral surface of the socket of the ball joint, thereby realizing a reduction in cost and weight (for example, see Patent Document 2).

  However, in the case of this configuration, the rigidity and strength of the apparatus cannot be said to be sufficient, and there is a problem that usable parts are limited.

  In general, when the ball portion and the ball sheet are pressed into the socket and then fixed by caulking, the surface pressure of the ball sheet increases due to the caulking load, and the torque tends to increase. In particular, in recent years, cases in which synthetic resins having a high elastic modulus such as polyetheretherketone (PEEK) are used for ball sheets have been increasing, and such a tendency of high torque has become more prominent.

JP 2003-148448 A (page 3-4, FIG. 1) Japanese Utility Model Publication No. 7-17608 (page 5-6, Fig. 1-2)

  As described above, there is a demand for a configuration of a ball joint device that can be reduced in weight, reduced in cost, and reduced in torque without reducing rigidity and strength.

  The present invention has been made in view of these points, and an object of the present invention is to provide a method for manufacturing a ball joint device capable of reducing weight, cost, and torque while ensuring rigidity and strength. .

  The ball joint device manufacturing method according to claim 1 includes a spherical ball portion, a synthetic resin bearing seat that holds the ball portion slidably inside, and a cylindrical shape that holds the bearing seat inside. A method of manufacturing a ball joint device comprising a ball joint having a socket and an arm portion having an end connected to an outer peripheral surface of the socket, wherein the ball portion and the bearing seat are assembled inside the socket. An assembling step and a welding step of welding the arm portion at a position where the center of the ball portion and the axis coincide with each other on the outer peripheral surface of the socket where the ball portion and the bearing seat are assembled.

  The ball joint device manufacturing method according to claim 2 is the ball joint device manufacturing method according to claim 1, wherein the welding step is performed by deforming and solidifying the end of the hollow cylindrical body. And welding the solidified end portion of the arm portion at a position where the center of the ball portion and the axial center coincide with each other on the outer peripheral surface of the socket assembled with the ball portion and the bearing seat. Is.

  The ball joint manufacturing method according to claim 3 is the ball joint device manufacturing method according to claim 1 or 2, wherein the welding step is performed at the center of the ball portion on the outer peripheral surface of the socket assembled with the ball portion and the bearing seat. Projection welding the arm portion at a position where the axis coincides with the axis.

  The method for manufacturing a ball joint device according to claim 4 is the method for manufacturing a ball joint device according to any one of claims 1 to 3, wherein the assembling step is performed after press-fitting the ball portion and the bearing seat into the socket. The ball portion and the bearing seat are assembled inside the socket by caulking and deforming an end portion of the socket.

  The ball joint device manufacturing method according to claim 5 is the ball joint device manufacturing method according to any one of claims 1 to 3, wherein the assembling step holds the ball portion and the ball portion slidably inside. The ball part and the bearing sheet are assembled into the socket by casting the socket with the bearing sheet as a core.

  According to the ball joint device manufacturing method of claim 1, after assembling the ball portion and the bearing seat to the socket, the arm portion is welded to a position where the center of the ball portion and the axis coincide with each other on the outer peripheral surface of the socket. As a result, it is possible to use a thinner and hollow member, for example, as the arm portion while ensuring rigidity and strength, so that the weight can be reduced, and a complicated manufacturing process is not required, so that the cost can be reduced. In addition, since the surface pressure on the ball portion of the bearing seat can be reduced by the welding heat of the arm portion, the torque can be reduced.

  According to the method for manufacturing the ball joint device according to claim 2, in addition to the effect of the method for manufacturing the ball joint device according to claim 1, the end of the hollow cylindrical body is deformed and solidified. Rigidity is achieved by forming an arm part and welding the solidified end of this arm part to a position where the center of the ball part coincides with the center of the axis on the outer peripheral surface of the socket assembled with the ball part and the bearing seat. Further, it is possible to easily reduce the weight of the arm portion while ensuring the welding strength.

  According to the method for manufacturing the ball joint device according to claim 3, in addition to the effect of the method for manufacturing the ball joint device according to claim 1 or 2, the ball portion is formed on the outer peripheral surface of the socket in which the ball portion and the bearing seat are assembled. Good welding strength can be ensured by projecting the arm portion at a position where the center of the shaft coincides with the axis.

  According to the method for manufacturing the ball joint device according to claim 4, in addition to the effect of the method for manufacturing the ball joint device according to any one of claims 1 to 3, after the ball portion and the bearing seat are press-fitted into the socket. Since the ball portion and the bearing seat are assembled inside the socket by caulking and deforming the end portion of the socket, the ball joint can be easily manufactured and the cost can be further reduced.

  According to the method for manufacturing a ball joint device according to claim 5, in addition to the effect of the method for manufacturing a ball joint device according to any one of claims 1 to 3, the ball portion and the ball portion are slidably provided inside. By casting the socket with the retained bearing seat as the core, the ball and bearing seat are assembled inside the socket, so there is no need for a separate process of assembling the ball and bearing seat inside the socket, making the ball joint easier Can be manufactured at a lower cost.

It is a longitudinal cross-sectional view which shows the ball joint apparatus manufactured by the manufacturing method of the ball joint apparatus of 1st Embodiment of this application. The welding process of the manufacturing method of the ball joint device is shown, (a) is an explanatory view showing the end side of the cylindrical body constituting the arm part, (b) is realized by plastic deformation of the end of the cylindrical body (C) is an explanatory view showing a state in which the solidified end portion of the cylindrical body is welded and connected to the outer peripheral surface of the socket. The assembly process of the ball joint manufacturing method of the ball joint device is shown, (a) is an explanatory view showing a state in which the ball portion and the bearing seat are press-fitted into the socket, and (b) is a state in which the socket is caulked and the ball portion and the bearing seat are attached. It is explanatory drawing which shows the state hold | maintained at the socket. The assembly | attachment process of the manufacturing method of the ball joint of the ball joint apparatus of the 2nd Embodiment of this invention is shown, (a) is explanatory drawing which shows the state which attached the ball | bowl part and the bearing seat to the metal mold | die, (b) It is explanatory drawing which shows the state which cast the socket by making a ball | bowl part and a bearing seat into a core.

  Hereinafter, the configuration of the first embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 10 denotes a ball joint link as a ball joint device used for, for example, a stabilizer link. This ball joint link 10 integrally includes a ball joint 11 and an arm portion 12 connected to the ball joint 11. I have.

  The ball joint 11 includes a socket 16 that is a housing, a ball sheet 17 that is a bearing seat accommodated in the socket 16, and a ball that is partially slidably held (rotated) by the ball sheet 17. A stud 18 and a dust cover 19 arranged from the outer peripheral surface of the socket 16 to the outer peripheral surface of the ball stud 18 are provided.

  The socket 16 has a cylindrical socket body 21 made of metal or the like, and a plug 22 as a disk-like closing member made of metal or the like that is integrally fixed to the socket body 21.

  The socket main body 21 has an inner chamber 24 for accommodating the ball seat 17 therein, and an insertion opening that communicates the inner chamber 24 with the outside of the socket main body 21 at one end (the upper end in FIG. 1). The first socket opening 25 which is one of the openings is further provided, and the other end (the lower end in FIG. 1) is provided at the other end as a communication opening for communicating the inner chamber 24 with the outside of the socket body 21. The second socket opening 26 is provided. Further, the socket body 21 is formed with a cover fixing groove 28 in the circumferential direction for fixing the end portion of the dust cover 19 on the outer peripheral surface on one end side (the upper end side in FIG. 1). Further, the socket body 21 is formed with a protruding portion 31 protruding in the central axis direction at a continuous portion between the inner chamber 24 and the first socket opening 25, and the inner chamber 24 and the second socket opening 26. A holding portion 32 for holding the plug 22 is formed in a stepped shape at the continuous portion. The socket body 21 is fixed to the socket 16 by fixing the plug 22 by caulking and deforming the other end side (the lower end side in FIG. 1) of the holding portion 32. This is a caulking fixing portion 33 which is a fixing portion for fixing to the head. The socket body 21 is formed by, for example, (cold) forging or casting.

  The first socket opening 25 is formed so as to gradually increase in diameter from the protruding portion 31 on the inner chamber 24 side toward one end side (the upper end side in FIG. 1).

  The second socket opening 26 has a diameter dimension substantially equal to that of the inner chamber 24.

  The cover fixing groove 28 is formed at a position outside the first socket opening 25.

  Further, the plug 22 is fixed by caulking and fixing with a caulking fixing portion 33 in a state where the peripheral portion is held by the holding portion 32, so that the other end side (the lower end side in FIG. 1) of the inner chamber 24, that is, the second socket. The opening 26 is closed.

  The ball seat 17 is made of synthetic resin such as polyether ether ketone (PEEK), which has excellent wear resistance and high elastic modulus, and is formed in a cylindrical shape that can be fitted into the inner chamber 24 of the socket body 21. Has been. That is, the ball seat 17 has a spherical sliding surface 35 inside, and the first end of the socket body 21 is connected to the sliding surface 35 at one end (upper end in FIG. 1). A first sheet opening 36 as one sheet opening serving as a sheet insertion opening communicating coaxially with the socket opening 25 is provided, and a sliding surface is provided at the other end (the lower end in FIG. 1). A second sheet opening 37 that is the other sheet opening is provided as a sheet communication opening that communicates coaxially with the second socket opening 26 of the socket main body 21 continuously to 35. The ball sheet 17 is held between the projecting portion 31 of the socket body 21 and the plug 22. Note that the ball sheet 17 may be formed by a single member, or may be configured by combining a plurality of members formed of, for example, synthetic resins having different characteristics.

  The ball stud 18 is made of, for example, steel, and integrally includes a spherical ball portion 41 and an axial stud portion 42 connected to the ball portion 41.

  For example, about 2/3 of the outer peripheral surface including the equator E (maximum diameter position) is held on the sliding surface 35 of the ball seat 17 so that the ball portion 41 can slide (turn). That is, the ball portion 41 is accommodated in the inner chamber 24 of the socket 16 together with the ball seat 17. The ball portion 41 is formed such that the outer diameter dimension of the equator E, that is, the maximum outer diameter dimension is substantially equal to the maximum inner diameter dimension of the sliding surface 35 of the ball seat 17. That is, the shape of the outer peripheral surface of the ball portion 41 substantially matches the shape of the sliding surface 35 of the ball seat 17. Further, although not shown, for example, a lubricant (grease) is held between the outer peripheral surface of the ball portion 41 and the sliding surface 35 of the ball seat 17. The ball center O, which is the center of the ball portion 41, is located on the central axis of the socket body 21 (socket 16) and is concentric with the sliding surface 35.

  The stud portion 42 is a portion to which a load from the outside is applied, and includes a round shaft-shaped stud portion main body 45 and a disc-shaped flange portion 46 integrally fixed to the outer periphery of the stud portion main body 45. Yes. The stud portion 42 may be formed integrally with the ball portion 41, or may be formed separately from the ball portion 41 and then integrated with the ball portion 41 by welding or the like.

  The stud body 45 is connected to the outer peripheral surface of the ball portion 41 coaxially with the ball center O of the ball portion 41. For this reason, the axial direction of the stud main body 45 (stud portion 42), that is, the axial center C1 is along the central axis of the socket main body 21 (socket 16) in an unloaded state, and with respect to the equator E of the ball portion 41. It is orthogonal (crossed) in front view. Further, on the outer peripheral surface on one end side (upper end side in FIG. 1) of the stud portion main body 45 of the stud portion main body 45, there is formed a screw portion 48 that is screwed and fixed to an attached member (not shown). Further, the stud main body 45 is inserted into the openings 36 and 25 and protrudes outward (upward in FIG. 1) from the ball seat 17 and the socket 16.

  The flange 46 forms a seating surface that comes into contact with the mounted member when the threaded portion 48 is fixed to the mounted member by screwing, and has a larger diameter than the stud body 45. .

  The dust cover 19 is also called a dust seal or a boot, and is formed in a flat cylindrical shape (a radial dimension is larger than the axial direction) by, for example, a soft rubber or a soft synthetic resin, and has an axial direction. The middle part bulges outward. The dust cover 19 is attached and fixed so that one end side (the upper end side in FIG. 1) is pressed in the direction of the central axis from the outer periphery of the flange 46 to the outer periphery of the stud body 45, and the other end ( The lower end side in FIG. 1 is attached and fixed to the cover fixing groove 28 of the socket 16. Therefore, the dust cover 19 covers the first socket opening 25 (the first sheet opening 36 of the ball seat 17) of the socket 16 regardless of the swinging of the ball stud 18, and enters the inside of the socket 16 or the ball seat 17. Prevents the intrusion of dust.

  On the other hand, the arm portion 12 is also called a link, and is formed, for example, in a straight line by a long cylindrical body 51 which is a hollow metal intermediate shown in FIG. The arm portion 12 includes a solid portion 52 in which one end portion of the cylindrical body 51 is solidified, and a hollow portion 53 having a hollow inside, and the solid portion 52 is the socket 16 (socket body 21). The outer peripheral surface is connected by welding, for example, by projection welding. That is, the solid part 52 is a projection (projection part) when the arm part 12 is welded to the outer peripheral surface of the socket 16 (socket body 21). As shown in FIG. 1, this arm portion 12 is a virtual position including the equator E of the ball portion 41, that is, the position where the ball center O of the ball portion 41 of the ball joint 11 coincides with the axis C <b> 2. At the intersection of the flat surface and the outer peripheral surface of the socket 16 (socket main body 21), it is welded and connected to the outer peripheral surface of the socket 16 (socket main body 21). That is, the ball center O of the ball portion 41 is located on the extension of the axis C2 at the end continuous with the socket 16 (socket body 21) of the arm portion 12, and the axis C2 is connected to the ball stud 18. It is orthogonal to (intersects with) the axis C1 of the stud portion 42 (stud portion main body 45). The other end portion of the arm portion 12 is not shown, but for example, the solid joint 52 may be formed similarly to the one end portion to weld the ball joint 11, or any shape different from the one end portion. You may have.

  The solid portion 52 is formed in a columnar shape having a smaller diameter than the hollow portion 53. Further, the solid portion 52 is integrally connected to the cavity portion 53 via a reduced diameter portion 55 that is gradually reduced in diameter from the cavity portion 53 side.

  The cavity 53 is formed to be longer than the solid part 52, for example, and is formed coaxially with the solid part 52. Therefore, the arm portion 12 is formed in a straight line shape.

  Next, a method for manufacturing the ball joint link 10 of the first embodiment will be described.

  First, the ball joint 11 side is assembled by the following assembly process. That is, as shown in FIG. 3 (a), the ball seat 17 holding the ball portion 41 slidably on the sliding surface 35 is press-fitted into the inner chamber 24 of the socket body 21 that has been separately forged or cast in advance. (Press-fit process)

  Next, as shown in FIG. 3 (b), the plug 22 is attached to the holding portion 32 of the socket body 21, and the peripheral edge of the other end (the lower end in the figure) of the socket body 21 is centered by a roller (not shown). By caulking and deforming to the side, the periphery of the plug 22 is caulked and fixed to the socket body 21 by the caulking fixing portion 33 (caulking fixing step). As a result, the ball portion 41 and the ball seat 17 are assembled and held inside the socket 16.

  On the other hand, the arm portion 12 is connected to the ball joint 11 side formed by the assembly process by a welding process described below. That is, the end portion of the hollow cylindrical body 51 shown in FIG. 2 (a) is plastically deformed as shown in FIG. 2 (b) to form the arm portion 12 having the solid portion 52 (solid). Step), the solid portion 52 is positioned so that the spherical center O of the ball portion 41 and the axial center C2 coincide with the outer peripheral surface of the socket body 21, as shown in FIGS. 1 and 2 (c). And welding by projection welding (connection process).

  Thereafter, the stud portion 42 is welded to the ball portion 41 in the socket body 21 to form the ball stud 18 and the dust cover 19 and the like are assembled to complete the ball joint link 10. The stud portion 42 may be welded to the ball portion 41 before connecting the cylindrical body 51 (arm portion 12) to the outer peripheral surface of the socket body 21.

  As described above, in the first embodiment, after the ball part 41 and the ball seat 17 are assembled to the socket 16 (socket body 21), the ball of the ball part 41 is formed on the outer peripheral surface of the socket 16 (socket body 21). The arm portion 12 is welded to a position where the center O and the axis C2 coincide.

  That is, since the ball center O of the ball portion 41 and the axis C2 of the arm portion 12 coincide with each other, the rigidity and strength do not decrease. Further, for example, even if a thinner (thinned shaft) and hollow member (tubular body 51) is used as the arm portion 12 (cavity), the rigidity and strength can be ensured, so that the weight can be reduced.

  Further, since the ball joint link 10 does not require a complicated manufacturing process, the cost can be reduced, and the surface of the sliding surface 35 of the ball seat 17 with respect to the outer peripheral surface of the ball portion 41 by the welding heat of the arm portion 12. Since the pressure can be reduced, the torque can be reduced.

  In addition, the solid portion 52 of the arm portion 12 that forms the solid portion 52 that is solidified by plastic deformation of the end portion of the hollow cylindrical body 51 is connected to the ball portion on the outer peripheral surface of the socket 16 (socket body 21). By welding at a position where the ball center O and the axis C2 coincide with each other, the arm portion 12 can be easily reduced in weight while ensuring rigidity and strength. That is, when the hollow cylindrical body 51 itself is welded to the socket 16 (socket body 21), the amount of penetration between the arm portion 12 and the socket 16 (socket body 21) during welding and the leg length of the weld bead are not sufficient. In addition, when the solid arm portion is welded to the socket 16 (socket body 21) in order to ensure the above penetration amount and the leg length of the weld bead, the arm portion 12 becomes heavy. . Therefore, the end of the hollow cylindrical body 51 is solidified to form a solid portion 52, and the solid portion 52 is welded to the socket 16 (socket body 21), thereby reducing the weight of the arm portion 12. Rigidity and strength can be secured.

  Furthermore, projection welding is performed when the solid part 52 of the arm part 12 is welded to the position where the spherical center O of the ball part 41 and the axial center C2 coincide with each other on the outer peripheral surface of the socket 16 (socket body 21). As a result, good welding strength can be secured.

  Further, after the ball part 41 and the ball sheet 17 are press-fitted into the socket 16 (socket body 21), the end part of the socket 16 (socket body 21) is caulked and deformed to thereby attach the ball part 41 and the ball sheet 17 to the socket. Since it is assembled in the interior of the socket 16 (socket body 21), the ball joint 11 can be easily manufactured and the cost can be further reduced.

  The ball joint link 10 configured as described above can be reduced in weight, cost, and torque while ensuring rigidity and strength. improves.

  Next, a second embodiment will be described with reference to FIG. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, the socket 16 (socket body 21) of the ball joint 11 is cast using the ball portion 41 and the ball seat 17 as a core in the first embodiment.

  That is, first, as shown in FIG. 4 (a), first, a ball sheet 17 previously molded separately by synthetic resin injection molding or the like is formed on the outer peripheral side of a portion of the ball portion 41 including the equator E. Assemble to cover the equator E.

  Next, as shown in FIG. 4 (b), a ball sheet 17 holding the ball portion 41 is inserted into a die casting mold 59 constituted by a first mold 57 and a second mold 58, and in this state the die casting is performed. A molten metal that is a molten metal such as high-temperature aluminum is press-fitted into the cavity C of the mold 59 and solidified to cover the entire outer peripheral surface of the ball sheet 17 and non-contact with the ball portion 41 (socket body 21 ). At this time, the ball sheet 17 receives heat from the molten metal, but has heat resistance that can withstand the heat, and the heat from the molten metal does not cause vaporization and consumption to an unusable level.

  That is, the molten metal pressed into the cavity C has a temperature higher than the heat resistance temperature of the synthetic resin that forms the ball sheet 17, but the synthetic resin that forms the ball sheet 17 requires latent heat for vaporization, Further, since its thermal conductivity is remarkably small, the progress of vaporization is extremely gradual, and it is possible to easily stop the progress of vaporization exhaustion to the inside with a slight advance of the cooling process performed in a normal casting process. Therefore, even if a molten metal having a temperature higher than the heat resistance temperature of the synthetic resin forming the ball sheet 17 is pressed into the cavity C, the ball sheet 17 is not vaporized and consumed to a level where it cannot be used due to heat from the molten metal. By this molding, it is possible to complete the assembly simultaneously with the molding of the socket 16 (socket body 21) without requiring a separate process of assembling the ball portion 41 and the ball sheet 17 to the socket 16 (socket body 21).

  Further, similarly to the first embodiment, after the plug 22 is attached to the socket body 21 and the ball joint 11 side is configured, the arm portion 12 is attached to the socket by a welding process similar to the first embodiment. The ball joint link 10 is obtained by welding to the outer peripheral surface of the 16 (socket body 21), welding the stud portion 42 to the ball portion 41, and attaching the dust cover 19.

  As described above, according to the second embodiment, the socket 16 (socket body 21) is cast with the ball portion 41 and the ball sheet 17 holding the ball portion 41 slidably therein as a core. As a result, the ball part 41 and the ball seat 17 are assembled into the socket 16 (socket body 21), so that the process of assembling the ball part 41 and the ball sheet 17 into the socket 16 (socket body 21) is not required. 11 can be manufactured more easily and cost can be reduced.

  In each of the above embodiments, the ball stud 18 that does not have the flange 46 may be used. Further, the ball joint 11 may have a configuration in which the stud portion 42 is not connected to the ball portion 41, or a configuration in which a pair of stud portions 42 are connected to the ball portion 41.

10 Ball joint link as a ball joint device
11 Ball joint
12 Arm
16 socket
17 Ball seat as bearing seat
41 Ball
51 cylinder

Claims (5)

A spherical ball portion, a bearing seat made of a synthetic resin that holds the ball portion slidably inside, a ball joint including a cylindrical socket holding the bearing seat inside, and an outer peripheral surface of the socket A method of manufacturing a ball joint device including an arm portion connected to an end of the ball joint device,
An assembly step of assembling the ball portion and the bearing seat inside the socket;
And a welding step of welding the arm portion at a position where the center of the ball portion and the axis coincide with each other on the outer peripheral surface of the socket assembled with the ball portion and the bearing seat. Manufacturing method. The welding step includes a solidifying step of forming an arm portion by deforming and solidifying the end of the hollow cylindrical body, and the ball is formed on the outer peripheral surface of the socket assembled with the ball portion and the bearing seat. The ball joint device manufacturing method according to claim 1, wherein the solidified end portion of the arm portion is welded to a position where the center of the portion coincides with the axis. 3. The ball according to claim 1, wherein in the welding step, the arm portion is projected and welded to a position where the center of the ball portion and the axis coincide with each other on the outer peripheral surface of the socket assembled with the ball portion and the bearing seat. A method for manufacturing a joint device. The assembly step includes assembling the ball portion and the bearing seat into the socket by press-fitting the ball portion and the bearing seat into the socket, and then caulking and deforming an end portion of the socket. The manufacturing method of the ball joint apparatus as described in any one of 1 thru | or 3. The assembling step is characterized in that the ball part and the bearing sheet are assembled into the socket by casting the socket with the ball part and the bearing sheet holding the ball part slidably therein as a core. A method for manufacturing a ball joint device according to any one of claims 1 to 3.

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