JP7479796B2 - Dust cover for ball joint - Google Patents

Description

The present invention relates to a dust cover for a ball joint.

2. Description of the Related Art In general, ball joints are widely used as connecting members between suspension and steering links in automobiles and the like.
In a ball joint, the ball head of a ball stud attached to a socket rotates within a predetermined angular range.
A dust cover is provided to prevent foreign matter such as muddy water or dust from entering the space in which the ball head rotates.
The dust cover is attached to the socket by means of a reinforcing ring, band, circlip or the like.
When a fastening member such as a band or circlip that tightens from the outer periphery of the dust cover is attached, the fastening member adheres closely to the dust cover and tightens it from the outer periphery, making it possible to more reliably prevent foreign matter from entering the dust cover and to retain grease placed in the space in which the ball head rotates inside the dust cover.
However, when fastening members are used to tighten the dust cover from its outer periphery, depending on the shape of the socket that houses the fastening members, the dust cover and the fastening members may move, causing the fastening members to come loose from the dust cover.

Patent Document 1, an example of the prior art, discloses a dust cover for a ball joint that can prevent the circlip from coming loose by providing a protrusion (82) for preventing the circlip from coming loose in a groove that houses the circlip, which is a fastening member that is tightened from the outer periphery of the large diameter opening of the dust cover that is attached to the socket.

JP 2012-92858 A

As mentioned above, when attaching the dust cover to the socket using fastening members that tighten around the outer periphery of the dust cover, the fastening members may come loose when the ball stud swings.

The present invention was made in consideration of the above, and aims to provide a dust cover for a ball joint that has a simple structure and is less likely to come loose than conventional fastening members.

The present invention, which solves the above problems and achieves the object, is a dust cover for a ball joint that is attached to the outer periphery of a socket of a ball joint that includes a ball stud with a shaft attached to a ball head, and a socket that has an opening into which the ball stud is inserted and a storage section in which the ball head is stored, and is fastened from the outer periphery by a fastening member, and is provided with a small diameter opening that is attached to the ball stud and a large diameter opening that is attached to the socket, and the mounting surface of the fastening member that comes into contact with the fastening member is formed on the outside of a recess provided on the outer periphery of the socket, and the mounting surface of the fastening member has an inclined surface that becomes deeper toward the bottom in a cross-sectional view.

The dust cover for a ball joint having the above configuration may have the mounting surface formed on the outside of the recess between an upper convex portion formed with a curved surface and a lower convex portion having a flat surface on the recess side.

The dust cover for a ball joint having the above configuration may have the mounting surface formed on the outside of the recess between an upper convex portion formed with a curved surface and an inclined surface that inclines so as to spread out from the recess toward the outer periphery.

The present invention, which solves the above problems and achieves the object, is a dust cover for a ball joint that is attached to the outer periphery of a socket of a ball joint that includes a ball stud with a shaft attached to a ball head, and a socket that has an opening into which the ball stud is inserted and a storage section in which the ball head is stored, and is fastened from the outer periphery by a fastening member, and is provided with a small diameter opening that is attached to the ball stud and a large diameter opening that is attached to the socket, and the mounting surface of the fastening member that comes into contact with the fastening member is formed on the outside of the lower side of a protrusion provided on the outer periphery of the socket, and the mounting surface of the fastening member has an inclined surface that becomes deeper toward the upper side in a cross-sectional view.

The dust cover for a ball joint having the above configuration may have the mounting surface formed on the outside of the portion sandwiched between the protruding portion having a flat surface on the underside and the inclined surface that is inclined so that the underside spreads outward toward the outer periphery.

The present invention has the effect of providing a dust cover for a ball joint that has a simple structure and is less likely to come loose than conventional fastening members.

1 is a cross-sectional view showing a ball joint to which a ball joint dust cover according to a first embodiment is attached. FIG. 2 is an enlarged cross-sectional view of the vicinity of a recess shown in FIG. 1 . 11 is a cross-sectional view showing a ball joint to which a dust cover for a ball joint according to a second embodiment is attached. FIG. FIG. 4 is an enlarged cross-sectional view of the vicinity of a protrusion shown in FIG. 3 . 13 is an enlarged cross-sectional view of the vicinity of a protrusion in a socket of a modified example of the second embodiment. FIG. FIG. 13 is an enlarged cross-sectional view of a socket according to a modified example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings.
However, the present invention should not be construed as being limited to the following embodiments.

<Embodiment 1>
FIG. 1 is a cross-sectional view showing a ball joint 10 to which a ball joint dust cover 14 according to this embodiment is attached.
The ball joint 10 shown in FIG. 1 includes a ball stud 11 , a socket 12 , a ball joint dust cover 14 , a band 15 , and a knuckle 16 .
The socket 12 shown in FIG. 1 has a recess 13 formed on its outer periphery.

The ball stud 11 has a shaft portion 112 attached to a ball head portion 111, and the ball head portion 111 rotates within a predetermined angle range.

The socket 12 has an opening 121 into which the ball stud 11 is inserted and a storage section 122 into which the ball head 111 is stored.

The recess 13 is a part provided on the outer periphery of the socket 12 where the ball joint dust cover 14 is attached, and is formed by machining.

The dust cover 14 for the ball joint has a small diameter opening 143 at one end which is attached to and sealed around the shaft portion 112 of the ball stud 11, a large diameter opening 141 at the other end which is attached to and sealed in the recess 13 provided on the outer periphery of the socket 12, and a membrane portion 142 located between the small diameter opening 143 and the large diameter opening 141.
The ball joint dust cover 14 prevents foreign matter from entering the storage section 122 .

The band 15 is a fastening member that is disposed at the position of the recess 13 and comes into contact with the ball joint dust cover 14 to fasten the ball joint dust cover 14 from its outer periphery.
Here, a circlip may be used as the fastening member instead of the band 15 .
However, when the band or circlip tightens the ball joint dust cover 14 from its outer periphery, the band or circlip may come off the ball joint dust cover 14 .

FIG. 2 is an enlarged cross-sectional view of the vicinity of the recess 13 shown in FIG.
The recess 13 shown in FIG. 2 is formed in a portion sandwiched between an upper protrusion 131 and a lower protrusion 133 .

The lower convex portion 133 shown in FIG. 2 has a flat surface on the side of the concave portion 13 with which the ball joint dust cover 14 contacts, and thus acts as a stopper that prevents the ball joint dust cover 14 from slipping out downwards. Therefore, even with a conventional ball joint dust cover of approximately uniform thickness, it is possible to prevent the band 15 from slipping out downwards.
However, as shown in FIG. 2, if the upper convex portion 131 is formed with a curved surface and does not have a flat surface on the side of the concave portion 13 with which the ball joint dust cover 14 comes into contact, then when a conventional ball joint dust cover of approximately uniform thickness is attached to the socket 12, the band 15 may slip out to the upper side when the ball stud 11 swings.
The upper convex portion 131 formed with such a curved surface can be formed by crimping.
It should be noted that, here, a plane is a flat surface, and a curved surface is a surface having a shape opposite to a plane and having a curvature, and in cross section, a plane is represented by a straight line, and a curved surface is represented by a curved line.

Therefore, in this embodiment, as shown in FIG. 2, the band mounting surface 140 of the ball joint dust cover 14 has an inclined surface that becomes deeper from the top to the bottom.
As band 15 is tightened onto band attachment surface 140 shown in FIG. 2, the upper portion of band 15 comes into contact with ball joint dust cover 14, band 15 slides along the inclined surface, and the lower portion of band 15 comes into contact with the lower surface of band attachment surface 140, causing ball joint dust cover 14 to generate a force pressing band 15 downward, thereby pressing band 15 downward.
Therefore, the force pressing the ball joint dust cover 14 downward becomes stronger on the lower side of the band 15, making it difficult for the ball joint dust cover 14 to come off in the upward direction, thereby preventing the ball joint dust cover 14 from coming off the socket 12.

According to the present embodiment described above, it is possible to obtain a dust cover for a ball joint with a simple structure and in which the fastening member is less likely to come loose than in the past.

<Embodiment 2>
In the first embodiment, the band mounting surface of the ball joint dust cover has an inclined surface that becomes deeper toward the lower side of the socket, but the present invention is not limited to this.
In this embodiment, a form will be described in which the band mounting surface of the ball joint dust cover has an inclined surface that becomes deeper toward the upper side of the socket.

FIG. 3 is a cross-sectional view showing a ball joint 10a to which a ball joint dust cover 14a according to this embodiment is attached.
A ball joint 10a shown in FIG. 3 has a socket 12a instead of the socket 12 in the ball joint 10 shown in FIG. 1, and a ball joint dust cover 14a instead of the ball joint dust cover 14, but the other configurations are the same.

The socket 12a differs from the socket 12 in that it does not have a recess 13 but has a protrusion 131a, but otherwise has the same configuration.
The protruding portion 131a has a flat surface on the lower side.

The ball joint dust cover 14a has a small diameter opening 143a at one end which is attached to and sealed around the shaft portion 112 of the ball stud 11, a large diameter opening 141a at the other end which is attached to and sealed around the outer periphery of the socket 12a, and a membrane portion 142a located between the small diameter opening 143a and the large diameter opening 141a.
The ball joint dust cover 14 a prevents foreign matter from entering the storage section 122 .

FIG. 4 is an enlarged cross-sectional view of the vicinity of the protruding portion 131a shown in FIG.
The protrusion 131a shown in FIG. 4 is provided on the outer periphery of the socket 12a and is formed by machining.

Convex portion 131a shown in FIG. 4 has a flat surface on the underside where ball joint dust cover 14a comes into contact, and thus acts as a stopper that prevents ball joint dust cover 14a from slipping out upwards. Even with a conventional ball joint dust cover of approximately uniform thickness, it is possible to prevent band 15 from slipping out upwards.
However, as shown in FIG. 4, because the socket 12a does not have a protrusion on the lower side, if a conventional ball joint dust cover of approximately uniform thickness is attached to the socket 12a, the band 15 may slip out to the lower side when the ball stud 11 swings.
It should be noted that, here, a plane is a flat surface, and a curved surface is a surface having a shape opposite to a plane and having a curvature, and in cross section, a plane is represented by a straight line, and a curved surface is represented by a curved line.

Therefore, in this embodiment, as shown in FIG. 4, the band mounting surface 140a of the ball joint dust cover 14a has an inclined surface that becomes deeper from the bottom to the top.
As band 15 is tightened onto band attachment surface 140a shown in Figure 4, the lower part of band 15 comes into contact with ball joint dust cover 14a, band 15 slides along the inclined surface, and the upper part of band 15 comes into contact with the upper surface of band attachment surface 140a, causing ball joint dust cover 14a to generate a force pressing band 15 upward, and band 15 is pressed upward.
As a result, the force pressing the ball joint dust cover 14a upward is stronger on the upper side of the band 15, making it difficult for the ball joint dust cover 14a to come off downward, thereby preventing the ball joint dust cover 14a from coming off the socket 12a.

Although FIG. 4 shows a socket having no lower protrusion, in which the lower side of the portion where the ball joint dust cover 14a is disposed is a vertical surface, the present invention is not limited to this.
In a socket that does not have a lower convex portion, the lower side of the portion where the ball joint dust cover 14a is disposed may be inclined.

FIG. 5 is an enlarged cross-sectional view of the vicinity of the protruding portion 131a in a socket 12b according to a modification of the present embodiment.
FIG. 5 differs from FIG. 4 only in that a socket 12b is shown instead of the socket 12a, and the rest of the configuration is the same.
The socket 12b shown in FIG. 5 has an inclined surface 123 that is inclined so that the lower side of the portion where the ball joint dust cover 14a is arranged widens toward the outer periphery, and the inclined surface 123 serves as an auxiliary stopper that prevents the ball joint dust cover from slipping out toward the lower side.
In the socket 12b shown in FIG. 5, a band attachment surface 140a is formed on the outside of the portion sandwiched between the convex portion 131a and the inclined surface 123, making it even more difficult for the ball joint dust cover 14a to come off in the downward direction, and preventing the ball joint dust cover 14a from coming off the socket 12b.

The present embodiment described above also makes it possible to obtain a dust cover for a ball joint with a simple structure that makes it more difficult for the fastening member to come loose than conventional ones.

When applying the present invention, the ball joint dust cover 14 described in embodiment 1 is attached to a socket that is shaped to easily come out in an upward direction, and the ball joint dust cover 14a described in embodiment 2 is attached to a socket that is shaped to easily come out in a downward direction.
For example, in a socket in which upper convex portion 131 is formed with a curved surface, such as socket 12 shown in FIG. 1 of embodiment 1, and which has an inclined surface 123, such as socket 12b shown in FIG. 5 of embodiment 2, inclined surface 123 acts as an auxiliary stopper that prevents the ball joint dust cover from slipping out downwards, so that it is difficult to slip out in a downward direction but is easy to slip out in an upward direction.
Therefore, the ball joint dust cover 14 shown in the first embodiment is attached to a socket having such a shape.

FIG. 6 is an enlarged cross-sectional view of a modified socket 12c.
Socket 12c shown in FIG. 6 has an upper convex portion 131 formed with a curved surface like socket 12, and an inclined surface 123 that is inclined so that the lower side of the portion where the ball joint dust cover is arranged widens toward the outer periphery like socket 12b, and a recess 13a is formed in the portion sandwiched between upper convex portion 131 and inclined surface 123.
In the socket 12c shown in Figure 6, the inclined surface 123 prevents the ball joint dust cover from falling out downwards, but since the upper convex portion 131 is formed as a curved surface, the ball joint dust cover tends to fall out upwards.
Therefore, for the socket 12c shown in FIG. 6, a ball joint dust cover 14 is attached to prevent it from coming loose in the upward direction, making it possible to make the fastening member less likely to come loose.

In the above-described first and second embodiments, it is assumed that the large-diameter openings 141 and 141a are not provided with reinforcing rings for mounting fastening members, but the small-diameter openings 143 and 143a may be provided with reinforcing rings.

The ball joint according to the present invention described above can be used, for example, as a connecting member between the suspension and steering links of an automobile, but is not limited to this.

10, 10a Ball joint 11 Ball stud 111 Ball head portion 112 Shaft portion 12, 12a, 12b, 12c Socket 121 Opening 122 Storage portion 123 Inclined surface 13, 13a Convex portion 131 Upper convex portion 131a Convex portion 133 Lower convex portion 14, 14a Dust cover for ball joint 140, 140a Band attachment surface 141, 141a Large diameter opening 142, 142a Membrane portion 143, 143a Small diameter opening 15 Band 16 Knuckle

Claims (4)

A dust cover for a ball joint is attached to the outer periphery of a socket of a ball joint including a ball stud having a shaft portion attached to a ball head portion, and a socket having an opening into which the ball stud is inserted and a storage portion into which the ball head portion is stored, and the dust cover is fastened from the outer periphery by a fastening member,
a small diameter opening adapted to be fitted onto the ball stud;
a large diameter opening that is fitted to the socket,
The large diameter opening is
an inner circumferential surface that contacts a bottom surface of a recess provided on an outer periphery of the socket;
an outer circumferential surface forming a mounting surface on which the fastening member is mounted on the back side of the inner circumferential surface,
The outer circumferential surface is
A dust cover for a ball joint, comprising an inclined surface that approaches the inner circumferential surface as it moves from the opening side toward the bottom side of the storage portion. The inner circumferential surface is
2. A dust cover for a ball joint as described in claim 1, which contacts a bottom surface of a recess sandwiched between a first convex portion formed with a curved surface near the opening and a second convex portion formed closer to the bottom of the storage section than the first convex portion and having a flat surface on the first convex portion side. The inner circumferential surface is
2. A dust cover for a ball joint as described in claim 1, which contacts the bottom surface of a recess sandwiched between a convex portion formed with a curved surface near the opening and an inclined surface formed on the bottom side of the storage section closer to the convex portion and inclined so as to widen toward the outer periphery of the socket. A dust cover for a ball joint is attached to the outer periphery of a socket of a ball joint including a ball stud having a shaft portion attached to a ball head portion, and a socket having an opening into which the ball stud is inserted and a storage portion into which the ball head portion is stored, and the dust cover is fastened from the outer periphery by a fastening member,
a small diameter opening adapted to be fitted onto the ball stud;
a large diameter opening that is fitted to the socket,
The large diameter opening is
an inner circumferential surface that contacts an adjacent outer circumferential surface adjacent to a protrusion provided on an outer periphery of the socket;
and an outer circumferential surface forming a mounting surface on which the fastening member is mounted on the back side of the inner circumferential surface,
The inner circumferential surface is
the protrusion has a flat surface on the bottom side of the storage section, and the inclined surface is formed on the bottom side of the storage section relative to the protrusion and inclined so as to spread toward the outer periphery of the socket, and the protrusion contacts the adjacent outer periphery surface sandwiched between the flat surface and the inclined surface,
The outer circumferential surface is
A dust cover for a ball joint, comprising an inclined surface that approaches the inner circumferential surface as it moves from the bottom side of the storage portion toward the opening side.

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