JP2012092865A - Bearing seat of ball joint and ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball seat of a ball joint which retains more certainly a lubricant arranged between a ball part and sliding surface to improve durability.SOLUTION: An annular groove part 61 is formed in a part, adjoining an auxiliary sliding part 52a, of the main sliding part 52b of the sliding surface 52 along a circumferential direction. The groove part 61 accommodates the lubricant arranged between the ball part press fitted onto the sliding surface 52 and the sliding surface 52. A protrusion 62 having an interference to the ball part is protrudingly formed adjacent to the side of the auxiliary sliding part 52a of the groove part 61. The lubricant is more certainly retained by the main sliding part 52b of the sliding surface 52 and the durability can be improved.

Description

  The present invention relates to a ball joint bearing seat used for a suspension device such as an automobile or a steering device, and a ball joint including the same.

  2. Description of the Related Art Conventionally, this type of ball joint used for a suspension device of a vehicle such as an automobile or a steering device includes a socket which is a bottomed cylindrical housing having an inner chamber and an opening communicating with the inner chamber. Yes. In addition, a cylindrical ball seat as a bearing seat is fitted in the inner chamber of the socket, and the ball portion of the ball stud is press-fitted and held rotatably in the ball seat. . Further, the stud portion of the ball stud projects from the other end of the socket to the outside of the socket and is connected to the vehicle body side.

  A fluid lubricant, that is, grease (lubricant) is held between the sliding surface in the ball seat and the ball portion to ensure slidability (see, for example, Patent Document 1). .

JP-A-11-173326 (page 3-4, FIG. 1)

  Among the ball joints configured as described above, in particular, in the so-called inverted compression type ball joint in which the ball portion of the socket, ball seat and ball stud is the upper side and the stud portion of the ball stud is the lower side, There is a demand for a structure capable of improving the durability by more reliably holding the grease between the ball and the ball portion.

  The present invention has been made in view of the above points, and includes a ball joint bearing seat that can more reliably retain a lubricant disposed between a ball portion and a sliding surface and improve durability. The purpose is to provide a ball joint.

  The ball joint bearing sheet according to claim 1 is a ball joint bearing sheet formed in a cylindrical shape, accommodated in a housing, and rotatably holding a ball portion of a ball stud via a lubricant. An opening located on the side, a cylindrical portion located in a portion corresponding to the equator position of the ball portion connected to the opening, and a reduced diameter portion that continues to the cylindrical portion and is gradually reduced in diameter toward the other end side A sliding surface on which the ball portion is press-fitted and a lubricant is disposed between the ball portion, and a portion adjacent to the cylindrical portion of the reduced diameter portion of the sliding surface in a circumferential direction. A groove formed annularly along the cylindrical portion and a portion adjacent to the cylindrical portion side of the groove formed annularly along the circumferential direction and has a tightening margin with respect to the ball portion press-fitted into the sliding surface And a protrusion protruding from the sliding surface It is those who are.

  The ball joint bearing sheet according to claim 2, wherein the ball joint bearing sheet according to claim 1 is formed so as to protrude from an inner edge portion of the opening and is press-fitted into the sliding surface while being accommodated in the housing. In contrast, a lip portion having a tightening allowance is provided.

  According to a third aspect of the present invention, there is provided a ball joint comprising: a housing; the bearing seat according to claim 1 or 2 housed in the housing; and a ball portion that is press-fitted into a sliding surface of the bearing seat and held rotatably. And a ball stud provided.

  According to the ball joint bearing sheet of claim 1, the annular groove portion is formed along the circumferential direction in a portion adjacent to the cylindrical portion of the reduced diameter portion of the sliding surface, thereby being press-fitted into the sliding surface. The lubricant disposed between the ball portion and the sliding surface is accommodated in the groove portion, and a protruding portion having an allowance for the ball portion is formed adjacent to the cylindrical portion side of the groove portion. Thus, the lubricant can be reliably held by the reduced diameter portion of the sliding surface, and the durability can be improved.

  According to the ball joint bearing sheet according to claim 2, in addition to the effect of the ball joint bearing sheet according to claim 1, the ball joint bearing sheet is press-fitted into the sliding surface while being accommodated in the housing at the inner edge of the opening. By projecting and forming the lip portion having a tightening margin with respect to the ball portion, the lubricant that has moved to the cylindrical portion side can be reliably held in the cylindrical portion by the lip portion, and the durability can be further improved.

  According to the ball joint of the third aspect, the durability can be improved by providing the bearing seat of the first or second aspect.

It is a longitudinal cross-sectional view which shows the bearing seat of one embodiment of this invention. It is a longitudinal cross-sectional view which shows the ball joint provided with the bearing seat same as the above.

  The configuration of an embodiment of the present invention will be described below with reference to FIGS.

  In FIG. 2, reference numeral 11 denotes a ball joint. The ball joint 11 is used for a suspension device of a vehicle such as an automobile or a steering device. The ball joint 11 includes a socket 16 that is a housing, a ball stud 17, and a substantially cylindrical cylinder that is a bearing seat that is slidably (rotatably) held in the ball stud 17 and is received in the socket 16. And a dust cover 19 disposed from the outer peripheral surface of the socket 16 to the outer peripheral surface of the ball stud 17 and having the socket 16 as an upper side, the so-called inverted compression type. In the following description, the lower side in FIGS. 1 and 2 is described as a lower side that is one end side, and the upper side is an upper side that is the other end side.

  The socket 16 is made of metal formed by, for example, (cold) forging or casting, and has a cylindrical main body portion 21, an inclined portion 22 continuous to the upper end side of the main body portion 21, and the inclined portion 22 It is formed in a covered cylindrical shape (bottomed cylindrical shape) that integrally has a closing portion 23 as a lid portion (bottom portion) continuous with the upper end of the lid. An inner chamber 24 is defined in the socket 16 by a body portion 21, an inclined portion 22, and a closing portion 23. The inner chamber 24 is connected to the outside of the socket 16 at the lower end portion of the socket 16. A circular socket opening 25, which is an opening that communicates, is formed.

  A cover fixing groove 27 as a cover mounting portion for mounting and fixing the upper end portion of the dust cover 19 is formed in an annular groove shape along the circumferential direction on the outer periphery on the lower end side of the main body portion 21.

  The inclined portion 22 is formed in a cylindrical shape whose diameter is gradually reduced from the lower end side (main body portion 21 side) to the upper end side (closed portion 23 side).

  The closing part 23 is formed along a direction substantially orthogonal to the axial direction of the socket 16 and closes the upper end of the inclined part 22.

  The inner chamber 24 is continuous with the inner chamber main body 24a located on the inner side of the main body 21 and the upper end side of the inner chamber main body 24a and extends from the inner side of the main body 21 to the inner side of the inclined portion 22. And an inner chamber closing portion 24c as an inner chamber lid portion (inner chamber bottom portion) continuous with the upper end of the inner chamber inclined portion 24b.

  The inner chamber inclined portion 24b is formed in a cylindrical shape whose diameter is gradually reduced from the lower end side (the inner chamber main body portion 24a side) to the upper end side (the inner chamber closing portion 24c side).

  The inner chamber blocking part 24c is located below the blocking part 23.

  An annular plug 31 is attached to the socket opening 25 as a holding member for preventing the ball seat 18 housed in the inner chamber 24 from coming off. The plug 31 is caulked and fixed by caulking and deforming the lower end side of the socket 16 toward the center while the outer peripheral edge is held by a holding portion 32 formed in a step shape along the inner edge of the socket opening 25. The part 33 is fixed to the socket 16.

  On the other hand, the ball stud 17 is made of, for example, steel, and integrally includes a spherical ball portion 41 and a shaft-shaped stud portion 42 connected to the ball portion 41.

  A part of the outer peripheral surface of the ball portion 41 is held by the ball seat 18 so as to be slidable (turnable). That is, the ball portion 41 is accommodated in the inner chamber 24 of the socket 16 together with the ball seat 18.

  The stud portion 42 is a portion to which a load is applied by being connected to an external connected member (not shown), and protrudes outward (downward in FIG. 2) from the socket 16. 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.

  As shown in FIGS. 1 and 2, the ball seat 18 is formed in a cylindrical shape, for example, made of synthetic resin having excellent wear resistance and high elastic modulus, and is fitted and held in the inner chamber 24 of the socket 16. Contained. The ball seat 18 includes a cylindrical seat main body 45, a seat inclined portion 46 continuous with the upper end of the seat main body 45, and a seat lid (sheet bottom) continuous with the upper end of the seat inclined portion 46. A sheet end 47 is provided integrally. Further, the ball seat 18 is formed with an opening 51 located at the lower end portion, and a sliding surface 52 that communicates with the opening 51 and holds the outer peripheral surface of the ball portion 41 is formed inside. .

  The seat main body 45 is a portion located inside the main body 21 of the socket 16 in a state where the ball seat 18 is fitted in the inner chamber 24. Further, the outer periphery of the lower end portion of the sheet main body 45 is a sheet protrusion 54 protruding outward. The seat protrusion 54 slides by being in contact with the inner chamber 24 of the socket 16 and being regulated in shape along the inner chamber 24 with the ball seat 18 fitted in the inner chamber 24 of the socket 16. The lower end side of the surface 52 is curved in a circular shape. Further, the lower end portion of the seat main body 45 is in contact with a plug 31 attached to the socket 16 in a state where the ball seat 18 is accommodated in the inner chamber 24 of the socket 16.

  The seat inclined portion 46 is a portion located inward of the inclined portion 22 of the socket 16 in a state where the ball seat 18 is fitted in the inner chamber 24, and the upper end side (the seat end 47 side) from the seat main body portion 45 side. It is formed in a cylindrical shape that is gradually reduced in diameter. Further, on the outer periphery of the seat inclined portion 46, a plurality of detent projections 55 for preventing the ball seat 18 fitted in the inner chamber 24 of the socket 16 from rotating in the circumferential direction with respect to the inner chamber 24. Are spaced apart from each other in the circumferential direction.

  The seat end portion 47 is a portion that is located inside the closing portion 23 of the socket 16 in a state where the ball seat 18 is fitted in the inner chamber 24 and that is separated from the closing portion 23. Further, the seat end portion 47 is separated from the outer peripheral surface of the ball portion 41. Further, a hole 57 that communicates with the inner chamber blocking portion 24c is formed through the sheet end 47 so as to close the sheet end 47 including the hole 57 from the position of the upper end of the sliding surface 52. A region 58 extending between the portion 23 and the portion 23 serves as a lubricant reservoir for storing the lubricant G disposed between the ball portion 41 and the sliding surface 52.

  The opening 51 communicates with the socket opening 25 of the socket 16 in a state where the ball seat 18 is fitted in the inner chamber 24. In addition, a lip portion 59 projects from the inner edge portion of the opening 51. The lip portion 59 is formed in an annular shape continuous over the entire circumferential direction, and the tip end side is formed in a convex arc shape. In addition, the lip portion 59 is in a state where the ball seat 18 is in a single state, that is, in a state where the ball seat 18 is not accommodated in the inner chamber 24 of the socket 16, with respect to the outer peripheral shape of the ball portion 41 (imaginary line A shown in FIG. 1). The ball portion 41 is press-fitted into the sliding surface 52 by being deformed on the lower end side of the ball seat 18 with the ball seat 18 being accommodated and held in the inner chamber 24 (with no fastening allowance). The tip side protrudes from the outer peripheral shape (imaginary line A shown in FIG. 1). Accordingly, the lip portion 59 has an allowance for the ball portion 41 press-fitted into the sliding surface 52 in a state where the ball seat 18 is accommodated in the inner chamber 24 of the socket 16. It is configured to be elastically compressed and liquid tightly adhered to the outer peripheral surface.

  The sliding surface 52 includes a sub-sliding portion 52a as a cylindrical portion located inward of the sheet main body 45, and the upper end of the sub-sliding portion 52a. And a main sliding portion 52b as a reduced diameter portion located inwardly of the sheet, and is formed continuously from the inside of the seat body 45 to the inside of the seat inclined portion 46. Further, a groove 61 is formed in an annular shape at a portion adjacent to the sub-sliding portion 52a of the main sliding portion 52b, and an annular protrusion 62 is provided at a portion adjacent to the sub-sliding portion 52a of the groove 61. Is formed to protrude.

  The auxiliary sliding portion 52a is a portion that holds a portion corresponding to the equator position E of the ball portion 41 press-fitted into the sliding surface 52, and holds the ball portion 41 so as to be slidable (rotatable) in an auxiliary manner. Part. Although the secondary sliding portion 52a is formed in a cylindrical surface shape when the ball seat 18 is in a single state, the ball seat 18 is accommodated in the inner chamber 24 of the socket 16, and the seat protruding portion 54 is deformed in the central direction. In the state, the lower end side which is the opening 51 side is configured to bend toward the center side so as to have a spherical shape along the outer peripheral surface of the ball portion 41. The equator position E of the ball portion 41 refers to the outer peripheral surface at the position where the diameter dimension is maximum in the direction intersecting (orthogonal) with the axial direction of the ball portion 41.

  The main sliding portion 52b is formed in a spherical shape whose diameter is gradually reduced from the lower end side (sub sliding portion 52a side) to the upper end side from the equator position E of the ball portion 41 press-fitted into the sliding surface 52. The ball portion 41 is a portion that mainly holds the ball portion 41 so as to be slidable (turnable).

  The groove portion 61 is adjacent to the main sliding portion 52b side of the protruding portion 62, and is formed in an annular shape that is continuous over the entire circumferential direction. The groove 61 is formed in a concave shape with respect to the sliding surface 52, and the lubricant G can be accommodated (stored) therein.

  Further, the projecting portion 62 is formed in an annular shape continuous over the entire circumferential direction, and the tip end side is formed in a convex arc shape. Further, the protruding portion 62 protrudes from the tip end side with respect to the outer peripheral shape of the ball portion 41 press-fitted into the sliding surface 52 (imaginary line A shown in FIG. 1). Accordingly, the projection 62 has a margin for the ball portion 41 press-fitted into the sliding surface 52, and is elastically compressed and liquid-tightly adhered to the outer peripheral surface of the ball portion 41. It is configured as follows. Further, the protruding portion 62 is in contact with the outer peripheral surface of the ball portion 41 at a position above the equator position E of the ball portion 41 press-fitted into the sliding surface 52.

  Further, the dust cover 19 is also called a dust seal or a boot, and covers the socket opening 25 of the socket 16 regardless of the swinging of the ball stud 17, such as moisture and dust inside the socket 16 or the ball seat 18. It prevents intrusion. The dust cover 19 is formed in a substantially cylindrical shape with, for example, a synthetic resin, the lower end side is fixed to the outer peripheral surface of the stud portion 42 of the ball stud 17, and the upper end side is fitted into the cover fixing groove 27 of the socket 16. It is fastened and fixed by a ring-shaped fixing member 65 attached to the outer peripheral surface.

  Next, the assembly work of the ball joint 11 of the above embodiment will be described.

  First, for example, with the lubricant G applied to the outer peripheral surface of the ball part 41 or the sliding surface 52 of the ball sheet 18, the ball part 41 is pressed into the sliding surface 52 from the opening 51 of the ball sheet 18, The portion 41 is rotatably held by the ball seat 18. The lubricant G may be injected between the ball portion 41 and the sliding surface 52 of the ball seat 18 from the outside in a subsequent process.

  At this time, the protrusion 62 has a tightening margin with respect to the outer peripheral surface of the ball portion 41, so that the protrusion 62 is compressed and pressed against the outer peripheral surface of the ball portion 41. Further, the lip portion 59 is separated from the outer peripheral surface of the ball portion 41. Further, the stud portion 42 of the ball stud 17 is in a state of protruding toward the opening 51 side of the ball seat 18.

  Next, the ball seat 18 holding the ball portion 41 of the ball stud 17 is inserted into the inner chamber 24 from the socket opening 25 of the socket 16 and fitted. In this state, the lower end side of the ball seat 18 is deformed toward the center side by the contact of the sheet protruding portion 54 with the inner chamber main body portion 24a of the inner chamber 24 of the socket 16, and in this deformed state, the ball portion 41 of the ball seat 41 is deformed. A lip portion 59 having a tightening margin with respect to the outer peripheral surface is compressed and pressed against the outer peripheral surface of the ball portion 41.

  Then, the plug 31 is inserted into the stud portion 42 of the ball stud 17 and attached to the holding portion 32 of the socket 16, and the lower end side of the socket 16 is deformed by caulking to the center side to form the caulking fixing portion 33. Thus, the plug 31 is held at the inner edge of the socket opening 25 of the socket 16. At this time, the rotation preventing projection 55 is compressed and pressed against the inner chamber inclined portion 24b. As a result, the ball seat 18 is fixed together with the ball stud 17 in a state in which it is prevented from rotating in the inner chamber 24 of the socket 16.

  Thereafter, the dust cover 19 is inserted into the stud portion 42 of the ball stud 17, the upper end side of the dust cover 19 is fastened and fixed to the cover fixing groove 27 by the fixing member 65, and the lower end side of the dust cover 19 is fixed to the ball. The ball joint 11 is completed by fixing to the outer periphery of the stud portion 42 of the stud 17.

  Next, the operation of the ball joint 11 of the above embodiment will be described.

  When a load from the vehicle body is applied to the ball stud 17, the ball stud 17 swings in the left-right direction.

  At this time, the ball portion 41 smoothly rotates (slides) on the sliding surface 52 by the action of the lubricant G disposed between the ball portion 41 and the sliding surface 52.

  The fluid lubricant G moves on the sliding surface 52, particularly on the main sliding portion 52 b as the ball portion 41 rotates, and a part thereof is accommodated and held in the groove portion 61. The lubricant G accommodated in the groove 61 is restrained from moving from the main sliding portion 52b side to the sub sliding portion 52a side by the sealing action of the projection 62 serving as the bank of the groove portion 61.

  As described above, the lubricant G on the main sliding portion 52b side is accommodated in the groove portion 61 or moves along the main sliding portion 52b, and the ball portion 41 rotates (slids) on the main sliding portion 52b. Sex is secured.

  Furthermore, even if the lubricant G escapes from the main sliding portion 52b to the secondary sliding portion 52a, the escaped lubricant G is held by the secondary sliding portion 52a by the sealing action of the lip portion 59. That is, the sliding surface 52 will not escape.

  As described above, according to the embodiment, by forming the annular groove 61 along the circumferential direction in the portion adjacent to the sub sliding portion 52a of the main sliding portion 52b of the sliding surface 52, The lubricant G arranged between the ball portion 41 press-fitted into the sliding surface 52 and the sliding surface 52 is accommodated in the groove portion 61, and the ball portion 41 is adjacent to the auxiliary sliding portion 52a side of the groove portion 61. By projecting the projecting portion 62 having a tightening margin with respect to the lubricant, leakage of the lubricant G accommodated in the groove portion 61 to the sub-sliding portion 52a side can be suppressed, and the lubricant G is particularly applied to the sliding surface 52. The main sliding portion 52b can securely hold and improve the durability.

  In addition, a lip portion 59 having a tightening margin with respect to the ball portion 41 press-fitted into the sliding surface 52 in a state accommodated in the socket 16 is formed on the inner edge portion of the opening 51 so as to protrude, so that the auxiliary sliding portion The lubricant G that has moved to the side of 52a can be reliably held by the lip portion 59 on the sub-sliding portion 52a, and the durability can be further improved.

  In addition, since the groove 61 serves as a relief of the protrusion 62 to which a load is applied due to the rotation of the ball part 41, it is possible to prevent an excessive load from being applied to the protrusion 62.

  Furthermore, the ball joint 11 can be improved in durability by including the ball seat 18. In particular, in the so-called inverted compression type ball joint 11 arranged with the socket 16 as the upper side, the ball portion 41 is mainly held in the main sliding portion 52b of the sliding surface 52 of the ball seat 18, so the groove portion 61 and the protrusion The lubricant G is securely held in the main sliding portion 52b by the portion 62, and the lubricant G that has escaped from the main sliding portion 52b to the secondary sliding portion 52a side is also caused by the lip portion 59 to serve as the secondary sliding portion 52a. Therefore, the lubricant G can be reliably held on the sliding surface 52 and durability can be improved.

  In the above embodiment, the ball stud 17 may not have the stud portion.

  Further, the ball joint 11 does not have to be of the inverted compression type, and is not limited to the vehicle steering device or the suspension device, and can be used at any connection location.

11 Ball joint
16 Socket which is housing
17 Ball stud
18 Ball seat as a bearing seat
41 Ball
51 opening
52 Sliding surface
52a Secondary sliding part as cylindrical part
52b Main sliding part as reduced diameter part
59 Lip
61 Groove
62 Protrusion E Equatorial position G Lubricant

Claims (3)

A ball joint bearing seat formed in a cylindrical shape, housed in a housing, and rotatably holding a ball portion of a ball stud via a lubricant,
An opening located on one end side;
A cylindrical portion located in a portion corresponding to the equator position of the ball portion communicating with the opening, and a reduced diameter portion that continues to the cylindrical portion and is gradually reduced in diameter toward the other end; And a sliding surface on which a lubricant is disposed between the ball portion and the ball portion,
A groove formed annularly along the circumferential direction in a portion adjacent to the cylindrical portion of the reduced diameter portion of the sliding surface;
A protrusion that is formed annularly along the circumferential direction in a portion adjacent to the cylindrical portion side of the groove portion and protrudes from the sliding surface so as to have a tightening margin with respect to the ball portion press-fitted into the sliding surface. And a ball joint bearing seat. The ball according to claim 1, further comprising a lip portion that protrudes from an inner edge portion of the opening and has a tightening margin with respect to the ball portion that is press-fitted into the sliding surface while being accommodated in the housing. Joint bearing sheet. A housing;
The bearing seat according to claim 1 or 2, housed in the housing,
A ball joint comprising: a ball stud provided with a ball portion that is press-fitted into a sliding surface of the bearing seat and is rotatably held.

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