JP2020125816A - Ball joint - Google Patents

Abstract

To provide a ball joint capable of improving the adhesion of a projecting portion with respect to a groove portion.SOLUTION: A ball joint 11 has a ball stud 17 equipped with a collar portion 29 provided at a position separated from a ball portion 27 in a stud portion 28. The ball joint 11 has a cylindrical dust cover 19 that is attached to a socket 16 at one end portion and is attached to the stud portion 28 of the ball stud 17 at the other end portion to cover an opening portion 21 of the socket 16. The collar portion 29 of the ball stud 17 has a groove portion 29d on an outside surface 29c. The dust cover 19 is equipped with a projecting portion 38a fitted with the groove portion 29d, and has the other end portion formed within a range on the one end portion side of the stud portion 28 from the groove portion 29d.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ball joint including a tubular cover member that covers an opening of a housing.

Conventionally, for example, a ball joint used in a suspension device such as an automobile stabilizer link has a ball stud that is a ball-side member having a stud portion that is a ball portion and a shaft portion, a housing that is a receiving-side member, and a ball portion. And a bearing seat (ball seat) which is movably held and accommodated in the housing. The stud portion of the ball stud projects from the opening provided in the housing to the outside of the housing, and the opening portion of the housing is provided between the housing and the stud portion of the ball stud protruding to the outside of the housing. And a dust cover, which is a cylindrical cover member, is attached. The dust cover has one end held by the clip member with respect to the housing, and the other end held by tightening the stud portion of the ball stud.

A stud portion of the ball stud may be formed with a flange portion that forms a bearing surface with a mating member to which the ball joint is attached. The other end portion of the dust cover is attached to a portion of the flange portion extending from the ball portion side surface to the outer peripheral surface. At this time, the other end of the dust cover is more firmly fixed to the ball stud so that the lubricant held inside will not come off from the flange when the ball stud swings greatly and does not flow out to the outside. It is desired to do.

Therefore, there is known a configuration in which a concave portion is formed on the outer peripheral surface of the flange portion, and a convex portion to be inserted into the concave portion is provided at the other end of the dust cover so as to project (for example, refer to Patent Document 1).

JP, 2011-106477, A (4th page, Drawing 1-2).

However, in the above ball joint, since the other end of the dust cover extends beyond the recess, the insertion of the protrusion into the recess is restricted by the contact between the other end of the dust cover and the outer peripheral surface of the collar. There are cases. For example, in the case of a dust cover having a short convex portion, the other end portion of the dust cover hits the outer peripheral surface of the flange portion, so that the convex portion is not sufficiently inserted into the concave portion, and the adhesion of the dust cover in the concave portion is weakened. There is a problem. Such a problem similarly occurs in a ball joint used at any place.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ball joint that can improve the adhesion of the protrusion to the groove.

The ball joint according to claim 1 has a receiving member having an opening, a sliding member housed in the receiving member, a ball portion rotatably held by the sliding member, and one end portion of the ball member. A ball side member provided with a shaft portion connected to the ball portion and having the other end located outside the receiving member from the opening portion, and a flange portion provided at a position apart from the ball portion on the shaft portion. And a cylindrical cover member having one end attached to the receiving side member and the other end attached to the shaft of the ball side member to cover the opening. The cover member has a groove portion on a side surface, the cover member includes a convex portion fitted into the groove portion, and the other end portion is formed in a range from the groove portion to one end side of the shaft portion.

A ball joint according to a second aspect of the present invention is the ball joint according to the first aspect, wherein the groove portion is arranged on the outer surface of the flange portion, near the one axial end portion of the shaft portion.

The ball joint according to claim 3 is the ball joint according to claim 1 or 2, wherein the groove portion has a curved cross section and is formed in an annular shape around the flange portion, and the convex portion has a cross sectional shape of the groove portion. It is formed in a curved shape along with and is positioned in an annular shape around the collar portion.

According to the ball joint of claim 1, the cover member is formed with a convex portion that fits into a groove formed on the outer surface of the flange portion of the ball-side member, and the other end portion of the cover member is By forming in the range from the groove to the one end side of the shaft, it is possible to prevent the fitting of the protrusion with respect to the groove by the other end of the cover member, and improve the adhesion of the protrusion to the groove. ..

According to the ball joint of the second aspect, in addition to the effect of the ball joint of the first aspect, by arranging the groove portion on the outer side surface of the flange portion toward the one end portion in the axial direction of the shaft portion, the ball portion is formed. Since it is possible to suppress the distance from the center of the protrusion to the protrusion that fits in the groove, it is possible to suppress the amount of swinging of the cover member at the protrusion when the ball-side member swings around the ball, and the protrusion is The fitted state is more easily maintained, and the sealability on the other end side of the cover member can be more effectively maintained.

According to the ball joint of claim 3, in addition to the effect of the ball joint of claim 1 or 2, the groove has a curved cross section, and the projection has a curved cross section along the groove cross section. This makes it easier to attach the protrusion to the groove, and by forming the groove in an annular shape around the flange and positioning the protrusion in an annular shape around the flange, the position of the entire circumference of the flange can be improved. The protrusion can be brought into close contact with the groove.

It is sectional drawing which shows some ball joints of one embodiment of this invention.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 11 indicates a ball joint. The ball joint 11 is used for a suspension device of a vehicle such as an automobile. The ball joint 11 has a socket 16 which is a housing (receiving member), a ball stud 17 which is a ball member, and a socket 16 which holds a part of the ball stud 17 so as to be slidable (rotatable). A bearing seat (ball seat) 18 which is a sliding member accommodated in the above, and a dust cover 19 which is a cover member arranged from the outer peripheral surface of the socket 16 to the outer peripheral surface of the ball stud 17. In the following, the lower side of FIG. 1 will be described as the lower side that is one end side, and the upper side will be the upper side that is the other end side. Further, the longitudinal direction (that is, the vertical direction in FIG. 1) of the ball stud 17 in the upright state (neutral state) is called the axial direction, and the direction orthogonal to this axial direction is called the axial perpendicular direction. Therefore, the central axis of the ball joint 11 coincides (including substantially coincides) with the central axis of the ball stud 17 in the upright state (neutral state).

The socket 16 is made of metal, for example, and has a bottomed cylindrical shape. That is, the lower part of the socket 16 is closed, and the opening part 21 is opened in the upper part. Further, the socket 16 has an inner chamber 22 that is a housing portion that houses the bearing seat 18 defined therein. The inner chamber 22 communicates with the opening 21. Further, the socket 16 is formed with a cover mounting portion 23 to which the lower end portion of the dust cover 19 is mounted on the outside. Further, the socket 16 has a deformed portion 24 in which an upper end portion surrounding the opening portion 21 is caulked and deformed toward the central axis side. The diameter of the inner chamber 22 of the socket 16 is reduced by the deforming portion 24, and the bearing seat 18 is prevented from coming off from the inner chamber 22. The socket 16 may be integrally formed into a bottomed cylindrical shape by forging or casting, or may be divided into a plurality of members and assembled to each other to form a bottomed cylindrical shape.

The ball stud 17 is made of, for example, steel, and has a spherical ball portion 27, a stud portion 28 that is a shaft-like shaft portion whose lower end portion is connected to the ball portion 27, and an upper end portion side of the stud portion 28. And a collar portion 29 provided on the.

A part of the outer peripheral surface of the ball portion 27 is slidably (rotatably) held by the bearing seat 18 via a lubricant. That is, the ball portion 27 is housed in the inner chamber 22 of the socket 16 together with the bearing seat 18.

The stud portion 28 is a portion to which a load is applied by being connected to a connected member which is an external mating member (not shown). The stud portion 28 is arranged coaxially with the ball portion 27. That is, the central axis of the stud portion 28 is arranged so as to pass through the center of the ball portion 27. The stud portion 28 is inserted into the opening portion 21 and the upper end portion side thereof projects outward from the socket 16 (upward in FIG. 1). In the present embodiment, in the stud portion 28, a portion 28a extending from the ball portion 27 to the flange portion 29 is formed in a cylindrical shape having a substantially constant thickness. Further, the stud portion 28 is formed at the upper end portion of the flange portion 29, that is, the portion opposite to the ball portion 27 with respect to the flange portion 29 as a male screw portion which is a connecting portion, and is formed on the connected member. It is adapted to be screwed into the formed internal thread portion. The stud portion 28 may be integrally formed with the ball portion 27 by using the same material as the ball portion 27, or may be formed integrally with the ball portion 27 by welding or the like with the same material or a different material. May be.

The collar portion 29 is also called a knuckle or the like, and is a portion that forms a seating surface that abuts against a connected member to which the stud portion 28 is connected. The collar portion 29 is formed so as to protrude from the stud portion 28 in the direction perpendicular to the axis. Further, the collar portion 29 is formed in an annular shape and is continuous over the entire circumference of the stud portion 28 in the circumferential direction. The collar portion 29 is formed in a flat shape in which the vertical dimension, which is the thickness dimension, is smaller than the radial dimension. Further, the collar portion 29 includes a lower surface 29a that is an end surface on the ball portion 27 side, an upper surface 29b that is an end surface on the connected member side, that is, an end surface on the opposite side to the ball portion 27, and between the lower surface 29a and the upper surface 29b. The outer surface 29c is located. The lower surface 29a and the upper surface 29b each have a planar shape or a substantially planar shape along the axis perpendicular direction. That is, the lower surface 29a and the upper surface 29b are arranged in parallel or substantially parallel to each other. Further, the outer side surface 29c is formed in a cylindrical surface shape having an axial direction along the vertical direction. The outer side surface 29c is formed continuously over the entire circumference of the collar portion 29. On the outer side surface 29c, a groove 29d is formed on the lower side which is one end side of the stud portion 28 in the axial direction. That is, the groove portion 29d is formed with a constant width or a substantially constant width in the thickness direction of the collar portion 29 that is the axial direction of the stud portion 28, that is, on the lower side that is closer to the ball portion 27 than the position of the central portion C in the vertical direction. ing. The groove portion 29d is formed in an annular shape continuous over the entire circumference of the outer side surface 29c. The groove 29d has a curved cross section. The groove 29d of the present embodiment is formed so that its cross section is curved in a concave arc shape, for example. The groove 29d is located slightly above the lower end of the outer surface 29c of the collar 29. Therefore, in the flange portion 29, one step portion 29e is formed below the groove portion 29d of the outer side surface 29c, which is one axial end side of the stud portion 28, and the stud portion is formed more than the groove portion 29d of the outer side surface 29c. The other step portion 29f is formed on the upper side which is the other end side in the axial direction of the portion 28. The step portions 29e and 29f are formed in a strip shape over the entire circumference of the collar portion 29, respectively. Further, the other step portion 29f has a vertical width that is at least half the vertical dimension of the collar portion 29, and the one step portion 29e has a vertical width that is less than 1/4 of the vertical dimension of the collar portion 29. That is, the other step portion 29f is formed wider than the one step portion 29e. The collar portion 29 may be formed integrally with the stud portion 28 by using the same material as the stud portion 28, or may be formed by welding or the like with the stud portion 28 by using the same material as or a different material from the stud portion 28. It may be embodied.

The bearing sheet 18 is formed in a tubular shape (cylindrical shape), for example, made of synthetic resin having excellent wear resistance, and is fitted and held in the inner chamber 22 of the socket 16 and accommodated therein.

The dust cover 19, which is also called a dust seal or boot, covers the opening 21 of the socket 16 regardless of the swing of the ball stud 17, and prevents moisture and dust from entering the socket 16 or the bearing seat 18. To do. The dust cover 19 is formed of, for example, synthetic resin into a substantially cylindrical shape. Further, the dust cover 19 has a flat shape in which the axial dimension is smaller than the radial dimension. The dust cover 19 integrally includes a cylindrical cover body portion 31, a first fixing portion 32 fixed to the socket 16, and a second fixing portion 33 fixed to the ball stud 17. A lubricant (grease) is sealed inside the dust cover 19.

The cover main body portion 31 is formed such that the central portion in the vertical direction, which is the axial direction, bulges in the axially perpendicular direction with respect to both end portions. A protrusion 31a is formed in the central portion of the cover body 31 in the vertical direction.

The first fixing portion 32 is a portion held by the cover mounting portion 23 of the socket 16. That is, the first fixing portion 32 is a portion fixed to the outer peripheral side of the socket 16. The first fixing portion 32 is located at the lower end of the cover body 31. The first fixing portion 32 is formed by folding back in a U-shape in the direction perpendicular to the axis. A clip 35, which is a fixing member, is attached to the first fixing portion 32. The first fixing portion 32 is clamped and fixed to the cover attaching portion 23 by the clip 35.

The second fixing portion 33 is a portion that is assembled from the stud portion 28 of the ball stud 17 to the flange portion 29. The second fixing portion 33 is formed to have a smaller inner diameter dimension and outer diameter dimension than the first fixing portion 32. That is, the dust cover 19 has a smaller diameter at the upper end than at the lower end. The second fixing portion 33 is located at the upper end of the cover body 31. The second fixed portion 33 includes a fixed base portion 37 and an extension portion 38 extending from the fixed base portion 37.

The fixed base portion 37 is formed in a solid block shape integrated with the upper end portion of the cover body portion 31. At the position of the fixed base 37, the thickness of the dust cover 19 is set to be larger than at other positions. In the present embodiment, the fixed base portion 37 has an inner peripheral surface that serves as a facing portion 37a that faces the outer peripheral surface of the portion 28a of the stud portion 28, and an upper end surface that axially contacts the lower surface 29a of the collar portion 29. It is the flange contact portion 37b that contacts. The facing portion 37a is preferably slightly separated from the outer peripheral surface of the stud portion 28, but may be in contact with the outer peripheral surface of the stud portion 28 in the direction perpendicular to the central axis side.

The extending portion 38 extends upward from a position on the outer peripheral side of the fixed base portion 37. The extending portion 38 is formed in an annular shape that is continuous over the entire circumference of the dust cover 19. The upper end of the extending portion 38 is set to be equal to or lower than the central portion C of the collar portion 29. Further, the extending portion 38 has a convex portion 38a fitted into the groove portion 29d. The convex portion 38a has a curved cross section similarly to the groove portion 29d. The convex portion 38a of the present embodiment is formed so that its cross section is curved in a convex arc shape, for example. Further, the convex portion 38a is provided so as to project from the upper end portion of the extension portion 38 toward the central axis direction, that is, the convex portion 38a is located at the upper end portion of the extension portion 38 (dust cover 19). In the dust cover 19, there is no portion projecting above the convex portion 38a. That is, the upper end of the dust cover 19 is arranged in the range from the groove 29d to the base end side of the stud portion 28 of the ball stud 17, that is, in the range not exceeding the upper end of the groove 29d. Further, in the extending portion 38, a cover groove portion 38b facing the one step portion 29e of the flange portion 29 is formed in a groove shape below the convex portion 38a. That is, the convex portion 38a projects in a step shape from the other portion of the extending portion 38. The cover groove portion 38b is preferably slightly separated from the one step portion 29e, but may be in contact with the one step portion 29e.

Next, the operation of the above-described embodiment will be described.

In the ball joint 11, when the load from the vehicle body side is applied to the ball stud 17, the ball stud 17 swings in the left-right direction.

At this time, according to the present embodiment, the convex portion 38a fitted to the groove portion 29d formed on the outer surface 29c of the flange portion 29 of the ball stud 17 is formed on the dust cover 19 and the dust cover 19 is formed. By forming the upper end that is the other end of the groove 29d in the range from the groove 29d to the lower end that is the one end of the stud portion 28, the fitting of the protrusion 38a to the groove 29d is performed by the upper end of the dust cover 19. It is possible not to obstruct, that is, the convex portion 38a can be always fitted into the groove portion 29d, and the adhesion of the convex portion 38a to the groove portion 29d can be improved. Therefore, in the state where the dust cover 19 is assembled from the socket 16 to the ball stud 17, the groove 29d serves as a weir for the protrusion 38a. As a result, the ability to hold the outer surface 29c of the collar portion 29 of the ball stud 17 of the dust cover 19 is improved, and the ability of the dust cover 19 to follow the ball stud 17 as a whole and the dust cover 19 on the upper end side thereof are improved. The sealing property is improved. Therefore, even if the ball stud 17 swings largely, the adhesion between the upper end of the dust cover 19 and the ball stud 17 can be ensured, and the leakage of the grease sealed inside the dust cover 19 can be suppressed.

Further, by disposing the groove portion 29d on the outer surface 29c of the collar portion 29 near the lower end portion which is closer to one end portion of the stud portion 28 in the axial direction, the convex portion 38a fitted into the groove portion 29d from the center of the ball portion 27. Since it is possible to suppress the distance to, it is possible to suppress the amount of swinging of the dust cover 19 at the convex portion 38a when the ball stud 17 swings around the ball portion 27, and the state in which the convex portion 38a is fitted in the groove portion 29d It becomes easier to maintain, and the sealability on the upper end side of the dust cover 19 can be more effectively maintained.

Further, when the groove 29d has a curved cross section and the convex portion 38a has a curved cross-sectional shape along the sectional shape of the groove portion 29d, for example, when both the groove portion 29d and the convex portion 38a have a rectangular sectional shape, etc. Compared with the above, even if the dimensions of the dust cover 19 vary somewhat, the convex portion 38a can be easily adhered to the groove portion 29d, and the groove portion 29d is formed in an annular shape around the collar portion 29 to form the convex portion 38a. By locating the ring around the collar portion 29, the convex portion 38a can be brought into close contact with the groove portion 29d at the position of the entire circumference of the collar portion 29. Therefore, it is possible to suppress the leakage of the grease sealed inside the dust cover 19 at the positions around the entire circumference of the collar portion 29.

INDUSTRIAL APPLICABILITY The present invention can be suitably used as a stabilizer link of a suspension system of a vehicle such as an automobile.

11 ball joint
16 Housing that is the receiving member
17 Ball stud which is the ball side member
18 Bearing sheet that is a sliding member
19 Dust cover that is a cover member
21 opening
27 Ball
28 Stud that is the shaft
29 Tsuba
29c outer surface
29d groove
38a convex

Claims (3)

A receiving member having an opening,
A sliding member housed in the receiving member,
A ball portion rotatably held by the sliding member, a shaft portion having one end portion connected to the ball portion and the other end portion positioned outside the receiving member from the opening portion, and the shaft portion. A ball-side member having a collar portion provided at a position apart from the ball portion;
A tubular cover member having one end attached to the receiving member and the other end attached to the shaft of the ball member to cover the opening;
The collar portion has a groove portion on an outer surface,
The cover member includes a convex portion that is fitted into the groove portion, and the other end portion is formed in a range from the groove portion to one end side of the shaft portion. The ball joint according to claim 1, wherein the groove portion is arranged on an outer surface of the flange portion near one end portion in the axial direction of the shaft portion. The groove portion has a curved cross section and is formed in an annular shape around the collar portion,
The ball joint according to claim 1 or 2, wherein the convex portion is formed in a curved shape along the cross-sectional shape of the groove portion, and is positioned annularly around the collar portion.

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