JP5166104B2 - Ball joint - Google Patents

Description

The present invention relates to a ball joint mainly used as a connecting device for a vehicle link mechanism, and more particularly to a ball joint in which a rod is welded to a socket for housing a ball stud.

  Conventionally, as a ball joint used for connecting a vehicle suspension linkage, for example, a suspension arm and a stabilizer, one shown in FIG. 6 is known. In FIG. 6, the ball joint 100 includes a ball stud 102, a ball seat 104, a socket 106, a dust cover 108 and a rod 130.

  In the ball joint 100, a spherical portion 102a formed at one end of the ball stud 102 is incorporated into the socket 106 via the ball seat 104, and the opening portion 106a of the socket 106 is caulked to support the stud 102 so as to be swingable and rotatable. A dust cover 108 is installed between the ball stud 102 and the socket 106 to prevent water and dust from entering the inside through the opening 106 a of the socket 106.

A rod 130 that connects the suspension arm and the stabilizer is welded to the cylindrical outer peripheral surface 106b of the socket 106, and the other end of the rod 130 is connected to another ball joint (not shown).
JP-A-5-319062 JP 2005-61537 A

  However, in the conventional ball joint as shown in FIG. 6, the installation angle of the rod 130 with respect to the socket 106 is determined by design requirements when the ball joint 100 is mounted on a vehicle. There is a problem that even if it is desired to change the installation angle, it cannot be changed.

Further, there is a case where the angle θ of the central axis CL of the rod 130 with respect to the central axis CS of the socket 106 is required to be welded at an angle other than 0 ° or 90 ° due to the suspension layout and the like. As conventional examples, there are the following cases (1) and (2).
(1) Welding is performed with the center axis of the rod not perpendicular to the welding surface of the socket.
(2) As a welding surface of the socket, a plane that is perpendicular to the central axis of the rod is provided and welded.

  FIG. 7 is a cross-sectional view showing an embodiment (1) in which a rod is welded obliquely with respect to a welding surface of a socket in a conventional ball joint. 7, the ball joint 110 includes a ball stud 112, a ball seat 114, a socket 116, a dust cover 118, and a rod 140. The central axis CL of the rod 140 is not perpendicular to the bottom surface 116a of the socket 116 but is inclined at an angle γ. Thus, the rod 140 is welded.

  FIG. 8 is an explanatory view showing a method of welding the rod of FIG. 7, FIG. 8A shows the case where the welding end surface of the rod is perpendicular to the central axis of the rod, and FIG. 8B shows the welding of the rod. The case where the end face is parallel to the welding surface of the socket is shown, and FIG. 8C shows the component force of the crimping force acting on the welding surface.

  In FIG. 8A, since the bottom surface 116a which is the welding surface of the socket 116 is inclined with respect to the welding end surface 140a of the rod 140, when welding is performed by pressing in the direction P, the nugget generation of the welded portion is generated around the rod 140. Due to the non-uniformity in the direction, that is, a portion having a small degree of welding penetration occurs, the welding strength is reduced as compared with the case where the rod having the same cross-sectional area is uniformly melted in the circumferential direction.

  In such a case, after the socket 116 and the rod 140 are welded by projection welding or the like in order to compensate for the strength reduction, it becomes necessary to further reinforce the bead 160 as shown in FIG. 7 by arc welding or the like. It becomes a problem to increase.

  In FIG. 8B, welding is performed by cutting the welding end surface 140b of the rod 140 obliquely with respect to the central axis CL so as to be parallel to the bottom surface 116a of the socket 116. In this case, the welding end surface 140b is centered on the central axis. Since the shape is asymmetric with respect to CL, positioning in the direction DL around the central axis CL of the rod 140 is necessary during welding, which also increases the manufacturing cost.

  8A and 8B, the rod 140 is pressed in the direction P of the central axis CL to perform welding, so that the pressing direction P and the bottom surface 116a that is the welding surface are perpendicular to each other. Instead, as shown in FIG. 8C, a component force H parallel to the component force V perpendicular to the bottom surface 116a is generated by the crimping force P at the time of welding, and the rod 140 is welded by this component force H. There is also a problem that the dimensional accuracy after welding tends to be lowered.

  FIG. 9 is a cross-sectional view showing an embodiment (2) in which a rod is welded perpendicularly to a welding surface of a socket in a conventional ball joint. 9, the ball joint 120 includes a ball stud 122, a ball seat 124, a socket 126, a dust cover 128, and a rod 150. The ball joint 120 has a conical bottom surface 126a that is axisymmetric with respect to the central axis CS of the socket 126. The rod 150 is welded so that the angle δ of the central axis CL is vertical.

  In this case, since it is necessary to secure a larger area than the weld end face 150a of the rod 150 on the bottom face 126a which is the weld face of the socket 126, the size of the socket 126 can be increased by increasing the thickness so that the bottom 126b of the socket 126 extends downward. Increases weight and cost.

  FIG. 10 is an explanatory diagram showing the reason why the size of the socket of FIG. 9 is increased, and FIG. 10 (A) shows the reason why an axisymmetric welding surface cannot be secured without increasing the thickness of the bottom of the socket. 10 (B) shows a drawback when the welding surface of the socket is asymmetrical about the central axis of the socket.

  10A, when the socket 126 has the same size as the socket 116 shown in FIG. 7 and the rod 150 is to be welded on the same central axis CL as FIG. 9, the socket 150 is welded to the welding end surface 150a of the rod 150. The area of the bottom surface 126b, which is the welding surface of 126, is insufficient, and a part 150b of the welding end surface 150a of the rod 150 is detached from the bottom surface 126b of the socket 126. If welding is performed in this state, the strength of the welded portion decreases.

  However, by extending the bottom 126b of the socket 126 down to the position indicated by 126a, the rod 150 can be welded to the socket 126 without changing the area of the bottom 126b and the angle and position of the central axis CL of the rod 150. It becomes.

  In FIG. 10B, the thickness of the bottom 126b is suppressed by increasing the area by making the welding surface 126c of the socket 126 an asymmetric plane around the central axis CS, but the socket 126 is not symmetrical. Therefore, formability by forging or the like deteriorates, and positioning of the center axis CS of the socket 126 in the direction around the axis DS is necessary at the time of welding, which increases the number of welding processes.

  Further, in the case of FIG. 9, the angle of the welding surface 126a of the socket 126 with respect to the central axis CS must be changed in accordance with the welding angle θ according to the design requirements, and the socket 126 can be shared even with a slight difference in the welding angle θ. Therefore, the mass production effect cannot be obtained and the manufacturing cost increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lightweight, high-strength, high-accuracy ball joint that can be adapted to the welding angle of a rod according to the requirements for mounting on a vehicle at low cost.

In order to achieve this object, the present invention is configured as follows. First, the present invention provides a ball joint including a ball stud having a spherical portion, a socket having a spherical portion of the ball stud swingably and rotatably accommodated and having an opening on one side, and a rod welded to the outer surface of the socket. The socket has a radius that is equal to or greater than the radius of the cylindrical outer peripheral portion whose center axis is a line passing through the center of the opening and the spherical portion of the ball stud, and the center is the center of the spherical portion of the ball stud. A spherical portion formed on the entire surface opposite to the opening portion by the matching spherical surface is provided , and the rod is welded to the spherical portion so that the extension line of the central axis passes through the center of the spherical portion of the socket. .

The ball joint of the present invention is capable of welding a rod to a ball stud having a spherical portion and a shaft portion, an opening for projecting the shaft portion on one side of the ball stud so that the spherical portion of the ball stud can swing and rotate, and an outer surface. In a ball joint including a socket having a welded surface, the welded surface of the socket has a radius equal to or larger than the radius of the cylindrical outer peripheral portion whose center axis is a line passing through the center of the opening and the spherical portion of the ball stud. has, centered by spherical surface coincides with the center of the spherical portion of the ball stud, formed opposite the entire surface of the opening, characterized in Rukoto.

  According to the present invention, a spherical portion having a larger range than the projected end surface area of the rod is provided on the outer surface of the socket, and the end surface portion of the rod is connected to the socket so that the extension line of the central axis of the rod passes through the center of the spherical portion of the socket. By welding to the spherical surface, nuggets are generated in the circumferential direction of the welding surface of the rod without adding unnecessary weight to the socket and increasing the weight, or reducing the productivity by making the socket asymmetric about the central axis. Can be made uniform, and a light weight, high strength and high precision ball joint can be provided at low cost.

  In addition, a wider range of socket sharing is available for different welding angles of the rod to the socket, which is a requirement for mounting on a vehicle, and further cost reduction can be expected due to the mass production effect.

Furthermore, since the external force via the ball stud can always be received on the central axis of the rod, the welding strength and rod strength necessary to withstand the external force can be minimized, and thus by reducing the rod cross-sectional area, An inexpensive rod can be used.

  FIG. 1 is a cross-sectional view showing a first embodiment of the ball joint of the present invention. In FIG. 1, the ball joint 10 includes a ball stud 12, a ball seat 14, a socket 16, a dust cover 18, and a rod 40.

  In the ball joint 10, a spherical portion 12a formed at one end of the ball stud 12 is incorporated into a socket 16 via a ball seat 14, and an opening portion 16a of the socket 16 is caulked to support the stud 12 so as to be swingable and rotatable. A dust cover 18 is installed between the ball stud 12 and the socket 16 to prevent water and dust from entering through the opening 16 a of the socket 16.

  Here, an axis passing through the center of the opening 16a of the socket 16 and the center OB of the spherical portion 12a of the ball stud 12 is defined as a central axis CS of the socket 16, and the socket 16 is basically axisymmetric with respect to the central axis CS. doing.

  The bottom surface 16b of the socket 16 has a spherical portion 16c having a radius RS from the center OS on the central axis CS of the socket 16, and the spherical portion 16c has a central axis CL inclined at an angle θ with respect to the central axis CS of the socket 16. The end surface portion 40a of the rod 40 is welded to the socket spherical surface portion so that the extension line of the central axis CL passes through the center OS of the spherical surface portion 16c of the socket 16.

  FIG. 2 is a sectional view showing a second embodiment of the ball joint of the present invention. In FIG. 2, the ball joint 20 includes a ball stud 22, a ball seat 24, a socket 26, a dust cover 28, and a rod 50.

  In the ball joint 20, a spherical portion 22a formed at one end of the ball stud 22 is incorporated into a socket 26 via a ball seat 24, and an opening portion 26a of the socket 26 is caulked to support the stud 22 so as to be swingable and rotatable. A dust cover 28 is installed between the ball stud 22 and the socket 26 to prevent water and dust from entering through the opening 26 a of the socket 26.

  Here, an axis passing through the center of the opening 26a of the socket 26 and the center OB of the spherical portion 22a of the ball stud 22 is defined as a central axis CS of the socket 26, and the socket 26 is basically axisymmetric with respect to the central axis CS. doing.

  The bottom surface 26b of the socket 26 is composed of a spherical surface 26c having a radius RS from the center OB of the spherical portion 22a of the ball stud 22. The spherical surface 26c has a central axis CL inclined at an angle θ with respect to the central axis CS of the socket 26, and The end surface portion 50a of the rod 50 is welded to the socket spherical portion so that the extension line of the axis CL passes through the center OS of the spherical surface 26c of the socket 26 (the same point as the center OB of the spherical portion 22a of the ball stud 22).

  Therefore, in the embodiment shown in FIGS. 1 and 2, the sockets 16 and 26 are added with unnecessary meat to increase the weight, or the sockets 16 and 26 are asymmetrical about the central axis to reduce the productivity. In addition, nugget generation can be made uniform in the circumferential direction of the welding surfaces of the rods 40 and 50, and a lightweight, high-strength, high-precision ball joint can be provided at low cost.

  FIG. 3 is an explanatory view showing the weldable range of the rods of FIGS. 1 and 2, FIG. 3 (A) shows the first embodiment of FIG. 1, and FIG. Show. In FIG. 3A, the welding angle of the rod 40 with respect to the socket 16, that is, the angle θ between the central axis CL and the central axis CS can be arbitrarily set within the range of the angle α with respect to the center OS of the spherical portion 16c.

  3B, the welding angle θ of the rod 50 with respect to the socket 26 can be arbitrarily set within the range of the angle β with respect to the center OS of the spherical portion 26c. Accordingly, since one type of socket 16 or 26 can cope with a plurality of welding angles, the range of socket sharing is widened, and the cost can be reduced due to the mass production effect.

  Further, in the first embodiment shown in FIG. 1, the position of the center OS of the spherical surface 16c and the position of the center OB of the spherical portion 12a do not coincide with each other, but in the second embodiment shown in FIG. Is made to coincide with the center OB of the spherical portion 22a of the ball stud 22, so that the ball joint 20 of the second embodiment always receives an external force via the ball stud 22 on the central axis of the rod 50. Can do.

  4A and 4B are explanatory views showing the action in the ball joint of the external force transmitted from the ball stud to the rod. FIG. 4A shows the first embodiment of FIG. 1, and FIG. 4B shows the action of FIG. 2nd Embodiment is shown. In FIG. 4A, the ball stud 12 has a central axis CB that is in the same plane as the central axis CL of the rod 40, and the central axis CB is located on the center axis CL of the rod 40 with respect to the central axis CS of the socket 16. In this state, the tilt angle θ is the same as the tilt angle θ.

  However, since the position of the center OB of the spherical portion 12a of the ball stud 12 and the center OS of the spherical surface 16c of the socket 16 do not match, the center axis CB of the ball stud 12 and the center axis CL of the rod 40 are not on the same line. , E is shifted. Therefore, the external force F from the Bose stud 12 not only acts in parallel to the central axis CL of the rod 40 but also acts as a moment FE.

  4B, the ball stud 22 has the center axis CB in the same plane as the center axis CL of the rod 50, and the center axis CB is the center axis CL of the rod 50 with respect to the center axis CS of the socket 26. However, since the position of the center OB of the spherical portion 22a of the ball stud 22 coincides with the position of the center OS of the spherical surface 26c of the socket 26, the external force F from the boose stud 22 is the same. Acts directly on the central axis CL of the rod 50.

  The example shown in FIG. 4B is the most favorable state in which the external force F acts on the rod 50 linearly as it is, but in the second embodiment, the angle θ of the stud 22 (including other than the plane of the drawing). Regardless of whether or not the external force F via the ball stud 22 can always be received on the line of the central axis CL of the rod 50, the welding strength and the rod strength necessary to withstand the external force F can be minimized, so that the rod By reducing the cross-sectional area, a cheaper rod can be used.

  FIG. 5 is a cross-sectional view showing a third embodiment of the ball joint of the present invention, and shows a case where the welding angle θ is larger than that of the second embodiment shown in FIG. In FIG. 5, the ball joint 30 includes a ball stud 32, a ball seat 34, a socket 36, a dust cover 38 and a rod 60.

  The ball joint 30 incorporates a spherical portion 32a formed at one end of the ball stud 32 into a socket 36 via a ball seat 34, and caulks and forms an opening 36a of the socket 36 to support the stud 32 so that it can swing and rotate. A dust cover 38 is installed between the ball stud 32 and the socket 36 to prevent water and dust from entering the opening 36 a of the socket 36.

  Here, an axis passing through the center of the opening 36a of the socket 36 and the center OB of the spherical portion 32a of the ball stud 32 is defined as a central axis CS of the socket 36, and the socket 36 has a shape that is basically axisymmetric with respect to the central axis CS. doing.

  The outer peripheral portion 36b of the socket 36 has a spherical portion 36c having a radius RS from the center OB of the spherical portion 32a of the ball stud 32. The spherical portion 36c is inclined at an angle θ with respect to the central axis CS of the socket 36. In addition, the end surface portion 50a of the rod 50 is welded to the socket spherical portion so that the extension line of the central axis CL passes through the center OS of the spherical portion 36c of the socket 36 (the same point as the center OB of the spherical portion 32a of the ball stud 32). doing.

  In FIG. 5, the bottom surface 36d of the socket 36 is a flat surface, but this portion may also be a spherical surface 36c, so that the welding angle θ can be set in a large range.

The present invention is not limited to a ball joint used as a connecting device for a vehicle link mechanism, but can be applied to any ball joint that welds a rod to a socket, and is not limited to the above-described embodiment. It includes appropriate modifications that do not impair the process.

Sectional drawing which shows 1st Embodiment of the ball joint of this invention Sectional drawing which shows 2nd Embodiment of the ball joint of this invention. Explanatory drawing which shows the weldable range of the rod of FIG. 1 and 2 Explanatory drawing which shows the effect | action of the external force from the ball stud of FIG. Sectional drawing which shows 3rd Embodiment of the ball joint of this invention. Sectional view showing a conventional ball joint Sectional drawing which shows the prior art example which welds a rod diagonally with respect to the welding surface of a socket Explanatory drawing which shows the welding method of the rod of FIG. Sectional drawing which shows the prior art example which welds a rod perpendicularly with respect to the welding surface of a socket Explanatory drawing which shows the reason why the size of the socket of FIG. 9 becomes large

Explanation of symbols

10, 20, 30, 100, 110, 120: Ball joints 12, 22, 32, 102, 112, 122: Ball studs 14, 24, 34, 104, 114, 124: Ball seats 16, 26, 36, 106, 116, 126: Sockets 18, 28, 38, 108, 118, 128: Dust covers 40, 50, 60, 130, 140, 150: Rod 160: Bead CB: Ball stud central axis CS: Socket central axis CL: Rod center axis OB: Ball stud spherical center OS: Socket spherical part center θ: Rod welding angle

Claims (2)

In a ball joint comprising: a ball stud having a spherical portion; a socket having a spherical portion of the ball stud that is swingably and rotatably accommodated and having an opening on one side; and a rod welded to an outer surface of the socket. ,
The socket has a radius equal to or greater than the radius of a cylindrical outer peripheral portion whose center axis is a line passing through the center of the opening and the spherical portion of the ball stud, and the center is the center of the spherical portion of the ball stud. by matching spherical, provided with a spherical surface portion which is formed opposite the entire surface of the opening,
The rod joint is welded to the spherical surface portion so that an extension line of a central axis passes through the center of the spherical surface portion of the socket.
A ball stud having a spherical portion and a shaft portion, a socket having a spherical portion of the ball stud that is swingably and pivotably accommodated, an opening for projecting the shaft portion on one side, and a welding surface capable of welding a rod to the outer surface In a ball joint comprising
The welding surface of the socket has a radius equal to or greater than the radius of a cylindrical outer peripheral portion whose center axis is a line passing through the center of the opening and the spherical portion of the ball stud, and the center is the spherical portion of the ball stud. the spherical surface coincides with the center of the ball joint, characterized in Rukoto formed opposite the entire surface of the opening.

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