JP5975849B2 - Ball joint - Google Patents

Description

  The present invention relates to a ball joint including a ball stud having a ball portion slidably received in a housing.

  In recent years, with the development of vehicle technology such as sensors or in-wheel motors used in electric vehicles, the number of places where wiring and electric wires are used in vehicles has increased. For example, a configuration capable of supplying power from a vehicle power supply to the vicinity of the wheel is required. It has been.

  Therefore, conventionally, for example, a configuration in which a power source on the vehicle body side and a motor on the axle side are directly connected by a conductor (for example, refer to Patent Document 1), and a configuration in which conductive wires are disposed in a groove-type suspension link (for example, a patent). Reference 2), or a structure in which the suspension arm is formed of a conductive member, and the power source on the vehicle body side and the motor on the axle side are electrically connected by the suspension arm (see, for example, Patent Document 3). It has been known.

  However, in the configuration described in each of the above patent documents, it is not considered to secure the conductivity of the ball joint that performs a movement such as a swing or a rotation and directly connects the suspension and the knuckle. Ball joints generally use resin ball seats (bearing seats) and lubricants (grease) at the sliding parts, so they become insulators and make the ball joints conductive. It is not easy.

  In this regard, although it is conceivable to use a conductive synthetic resin or lubricant, these conductive synthetic resins and lubricants do not have sufficient conductivity.

  In addition, for example, a configuration is known in which a ball sheet that rotatably holds a ball portion in a housing is made of metal (see, for example, Patent Document 4). In this case, while the conductivity can be ensured, since the ball sheet and the ball part are both metal, wear of the ball sheet or the ball part may be promoted, and the reliability of the slidability is improved. It is not easy.

  Furthermore, for example, a configuration in which the ball sheet itself is formed of a synthetic resin containing a conductive material is known (see, for example, Patent Document 5). However, a synthetic resin containing a conductive material is generally expensive and has a high material hardness. Therefore, when used for the entire ball sheet, the cost increases and the moldability of the ball sheet is not good.

Japanese Patent Laying-Open No. 2005-75319 (page 3-5, FIG. 2-4) JP-A-6-278433 (page 2-3, FIG. 1-3) JP 2009-248902 A (page 3-5, FIG. 1) Japanese Utility Model Publication No. 62-15538 (page 2-3, Fig. 1) Japanese Patent Laying-Open No. 2007-107608 (page 5-7, FIG. 1)

  As described above, a ball joint that secures slidability and sliding reliability, is inexpensive, and secures electrical conductivity between the ball side member and the ball receiving side member is desired. Such a problem occurs not only in the field of vehicles but also in various electric devices having a movable part that moves three-dimensionally by connecting the ball side member and the ball receiving side member.

  The present invention has been made in view of the above points, and a ball that can secure the electrical conductivity between the ball side member and the ball receiving side member at low cost without affecting the slidability and the sliding reliability. The purpose is to provide joints.

  The ball joint according to claim 1 includes a ball portion, and includes a conductive ball side member attached to the attached portion, a sliding contact surface that rotatably holds the ball portion, and communication with the sliding contact surface. An insulating bearing sheet having a through-hole, a ball receiving part for receiving the ball part together with the bearing sheet, and a receiving part communicating with the through-hole of the bearing sheet received in the ball receiving part. An electrically conductive ball receiving side member, a conductor disposed at least partially in the through hole of the bearing seat, and electrically connected to the ball receiving side member; and the receiving portion of the ball receiving side member And an urging member that press-contacts the conductor to the ball portion.

  The ball joint according to claim 2 is the ball joint according to claim 1, wherein the conductor is formed of a resin containing a conductive material.

  A ball joint according to a third aspect is the ball joint according to the first or second aspect, wherein the through hole is provided at a position excluding the equator position of the ball portion of the sliding contact surface.

  According to the ball joint of claim 1, at least a part of the conductor electrically connected to the conductive ball receiving side member is disposed in the through hole communicating with the sliding contact surface of the insulating bearing seat. At the same time, the ball side member and the ball receiving side member can be electrically connected to each other through the conductor by press-contacting the electric conductor to the ball portion by an urging member disposed in the housing portion of the ball receiving side member. Therefore, the conductivity between the ball side member and the ball receiving side member can be secured at low cost by the conductor while ensuring the slidability of the ball portion by the sliding contact surface of the bearing seat.

  According to the ball joint according to claim 2, in addition to the effect of the ball joint according to claim 1, by forming the conductor with a resin containing a conductive material, by sliding between the ball portion and the conductor. Abrasion can be more reliably suppressed, and sliding reliability can be further improved.

  According to the ball joint of claim 3, in addition to the effect of the ball joint of claim 1 or 2, by providing the through hole of the bearing seat at a position excluding the equator position of the ball portion of the sliding contact surface, It is difficult for a load from the ball side member to be applied to the conductor at least a part of which is disposed in the through hole, wear due to sliding between the ball portion and the conductor can be more reliably suppressed, and sliding reliability can be further improved. .

It is sectional drawing which shows the ball joint of one embodiment of this invention.

  Hereinafter, the configuration of an embodiment of the present invention will be described with reference to FIG.

  In FIG. 1, reference numeral 11 denotes a ball joint. The ball joint 11 is a vehicle body side member positioned on the vehicle body side of a vehicle such as an automobile, for example, and a wheel (wheel) positioned on a suspension (suspension device) (not shown) and a wheel (wheel) side. It forms a suspension link that connects a knuckle as a side member. The ball joint 11 includes a ball stud 15 made of metal as a ball side member as a movable member, a metal housing 16 as a ball receiving side member as a fixed member, and the housing 16 and the ball stud. A ball seat 17 that is a bearing seat made of synthetic resin or the like interposed between the ball stud 15, a dust cover 18 that is a dustproof member disposed between the ball stud 15 and the housing 16, and the housing 16. And a conductive portion 19 to be disposed. In addition, the up-down direction shown below shall mean the up-down direction of FIG.

  The ball stud 15 is integrally formed of a conductive member such as aluminum, and has a ball portion 21 that is a substantially spherical sphere head, and a vertical shape such as a metal that protrudes from the ball portion 21 in the vertical direction. And a stud portion 22 which is a round shaft-shaped shaft portion.

  The ball portion 21 is attached to the housing 16 while being slidably (rotatably) held inside the ball seat 17.

  The stud portion 22 protrudes upward from the ball portion 21 at a position where the axial center passes through the center position of the ball portion 21, for example. Further, the stud portion 22 includes a diameter-expanding portion 24 that is a base end portion that gradually increases in diameter from the ball portion 21 side that is the base end side to the upper side (tip end side) that is the anti-ball portion 21 side. The diameter-reduced portion 25, which is a tapered portion as a connecting portion that gradually reduces in diameter from the upper side, which is the side opposite to the ball portion 21 of the diameter portion 24, to the upper side (tip side), The flange 56 protruding to the outer periphery of the continuous portion and the screw groove 27 which is a fixing portion provided at the upper end which is the tip of the reduced diameter portion 25 are integrally provided. Then, the reduced diameter portion 25 side of the stud portion 22 is inserted into the knuckle attachment portion, and a nut (not shown) is screwed into the screw groove 27, so that the ball joint 11 is connected and fixed to the knuckle. ing. In addition, this knuckle is electrically connected with the to-be-powered part arrange | positioned at the wheel side, such as an in-wheel motor, for example.

  The housing 16 is also referred to as a socket, and is provided integrally with, for example, an end of a suspension arm (not shown) to form a part of the suspension. For example, the housing 16 is formed in a cylindrical shape by a member such as iron or aluminum. Has been. The housing 16 includes an inner chamber 31 that is a ball receiving portion that holds the ball portion 21 via the ball seat 17, and an opening 32 that communicates with the inner chamber 31. Further, a communication hole 34 serving as a housing portion is provided through the central portion of the bottom 33 of the inner chamber 31 of the housing 16. Further, on the outer periphery of the housing 16 on the opening 32 side, a step portion 35 which is a groove-like cover groove into which the lower end side of the dust cover 18 is fitted is formed. The suspension is electrically connected to a power source arranged on the vehicle body side.

  The opening 32 is positioned coaxially with the housing 16. Further, the stud portion 22 of the ball stud 15 is inserted into the opening 32, and the upper side of the ball portion 21 and the stud portion 22 are exposed to the outside of the housing 16. The peripheral edge portion of the opening 32 is curved by caulking deformation or the like toward the center side to form a holding portion 36 for holding the ball seat 17 in the inner chamber 31.

  Further, the communication hole 34 has an opening area smaller than the opening 32 and is positioned coaxially with the housing 16. Furthermore, the lower end side of the communication hole 34 penetrates to the outside of the housing 16, and the lower end portion is covered and closed by a circular plate-like plug 37 that is a closing member. The plug 37 is formed by enclosing a metal member with a synthetic resin, and an outer peripheral edge portion is attached to an attachment step portion 40 formed outside the communication hole 34. The outer edge portion is fixed to the housing 16 by being held by a caulking deformation portion 41 that is a holding portion obtained by caulking inward deformation.

  Further, the ball sheet 17 is integrally formed of, for example, an insulating synthetic resin into a substantially cylindrical shape having an opening on the upper and lower surfaces. That is, the ball sheet 17 has a substantially circular end surface opening 45 and a through hole 46 whose opening diameter is smaller than the outer diameter of the ball portion 21 at the upper and lower ends that are both ends in the axial direction. In addition, a sliding contact surface 47 that is a holding surface that communicates with the end surface opening 45 and the through hole 46 is formed inside the ball sheet 17, and the sliding contact surface 47 slides on the outer peripheral surface 21 a of the ball portion 21. It can be moved (rotated). Therefore, the ball seat 17 is accommodated in the inner chamber 31 of the housing 16 together with the ball portion 21 of the ball stud 15, and the ball portion 21 is rotatably held in the inner chamber 31 via the ball seat 17. Has been. Further, a lubricant (grease) 48 is interposed between the sliding contact surface 47 of the ball seat 17 and the outer peripheral surface 21 a of the ball portion 21.

  Further, the through hole 46 of the ball sheet 17 communicates the sliding contact surface 47 with the outside of the ball sheet 17, and communicates coaxially with the communication hole 34 in a state where the ball sheet 17 is attached to the inner chamber 31 of the housing 16. It is supposed to be. That is, the through hole 46 of the ball seat 17 is formed to have the same diameter as the communication hole 34 of the housing 16, for example.

  Further, the sliding surface 47 of the ball seat 17 includes a region extending from the lower end side on the side opposite to the stud portion 22 of the ball portion 21 to the vicinity of the upper end side on the stud portion 22 side, including at least the equator position E of the ball portion 21. keeping. Here, the equator position E of the ball portion 21 refers to a position where the diameter dimension of the ball portion 21 is maximized in a direction orthogonal to the axial direction of the stud portion 22. Therefore, the through hole 46 is located on the sliding contact surface 47 excluding the position corresponding to the equator position E of the ball portion 21, in this embodiment, the anti-stud including the central axis of the ball stud 15 on the sliding contact surface 47. It is formed in the lower end portion that is the region on the side of the portion 22, in other words, in the region including the position farthest from the equator position E in the sliding contact surface 47, that is, the region including the position where the load of the ball stud 15 is not applied. . The ball seat 17 is, for example, a so-called two-piece type that is divided into a seat body portion that holds the ball portion 21 and a cushion portion that is attached in the ball portion 21 and elastically supports the ball portion 21. And so on.

  The dust cover 18 is also called a dust seal or boot, and is a flat, generally cylindrical shape in which the central portion between both ends in the axial direction bulges in the radial direction by an elastic member such as soft rubber or soft synthetic resin. Is formed. The dust cover 18 has an upper end portion that is one end portion in the axial direction fitted on the outer peripheral side on the ball portion 21 side of the flange portion 26 of the stud portion 22, and a lower end portion that is the other end portion in the axial direction is a step portion of the housing 16. The outer peripheral side of 35 is fixedly fitted.

  The conductive portion 19 includes a solid conductor 51 formed in a block shape and a coil spring 52 that is a biasing member that biases the conductor 51.

  The conductor 51 is formed of, for example, a columnar shape that fits so as to be movable (slidable) along the communication hole 34 and the through hole 46 with a resin containing a conductive material (for example, carbon black). The side protrudes from the through hole 46 toward the sliding contact surface 47 side of the ball sheet 17. Therefore, the conductor 51 is in sliding contact with the housing 16 and electrically connected to the housing 16 at the position of the communication hole 34. The tip 51a of the conductor 51 is formed in a circular arc shape that curves along the outer peripheral surface 21a of the ball portion 21, and the tip 51a is formed on the outer peripheral surface 21a of the ball portion 21 by the coil spring 52. On the other hand, it is pressed and adhered in a planar manner (with a large area). In other words, the conductor 51 is in surface contact with the ball portion 21.

  The coil spring 52 is located in the lower part of the conductor 51 in the communication hole 34, in other words, between the conductor 51 and the plug 37. The tip 51a of the conductor 51 is connected to the ball portion 21. The outer peripheral surface 21a is always in pressure contact.

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

  First, when the ball joint 11 is assembled, the balls of the ball stud 15 are held in a state where the outer peripheral surface 21a of the ball portion 21 of the ball stud 15 formed in advance is rotatably held by the sliding contact surface 47 of the ball seat 17. The portion 21 side and the ball seat 17 are press-fitted from the opening 32 into the inner chamber 31 of the housing 16 formed in advance. In this state, the stud portion 22 projects from the opening 32 above the housing 16, and the through hole 46 of the ball seat 17 communicates coaxially with the communication hole 34 of the housing 16. The lubricant 48 may be applied in advance to the outer peripheral surface of the ball portion 21 or may be injected later.

  Next, the holding portion 36 is formed by caulking and deforming the peripheral edge of the opening 32 of the housing 16 toward the center, and the ball portion 21 is held in the inner chamber 31 together with the ball seat 17.

  Further, with the conductor 51 and the coil spring 52 formed in advance inserted through the communication hole 34 of the housing 16, the outer peripheral edge of the plug 37 is attached to the mounting step 40, and the peripheral portion of the mounting step 40 is A caulking deformation portion 41 is formed by caulking deformation toward the center side, and the outer peripheral edge portion of the plug 37 is fixed.

  As a result, the coil spring 52 is in a state in which the tip 51a of the conductor 51 is in pressure contact with the outer peripheral surface 21a of the ball portion 21 exposed from the through hole 46 of the ball seat 17.

  Thereafter, the dust cover 18 is attached and fixed between the step portion 35 of the housing 16 and the flange portion 26 of the stud portion 22 of the ball stud 15, thereby completing the ball joint 11.

  In the completed ball joint 11, the reduced diameter portion 25 side of the stud portion 22 of the ball stud 15 is inserted into the attachment portion of the knuckle, and the nut is tightened in the screw groove 27, for example, the upper end portion of the dust cover 18 is seated. Connected and fixed to the knuckle as a surface. As a result, the suspension and the knuckle are electrically connected by the housing 16 and the ball stud 15 via the conductor 51 of the conductive portion 19. That is, the suspension and the knuckle are electrically connected through a path of the housing 16, the conductor 51, and the ball stud 15.

  As described above, according to the embodiment, a part of the conductor 51 that is electrically connected to the conductive housing 16 is formed in the through hole 46 that communicates with the sliding contact surface 47 of the insulating ball sheet 17. The conductor 51 (the tip 51a of the conductor 51) is pressed against the ball portion 21 (the outer peripheral surface 21a of the ball portion 21) by the coil spring 52 disposed in the communication hole 34 of the housing 16. Even if the ball seat 17 and the lubricant 48 act as insulators, the ball stud 15 and the housing 16 can be electrically connected via the conductor 51. Therefore, the electrical conductivity between the ball stud 15 and the housing 16 can be ensured by the conductor 51 while ensuring the slidability of the ball portion 21 by the sliding contact surface 47 of the ball seat 17.

  Moreover, as the ball sheet 17 constituting the slidable contact surface 47, a conductor 51 that protrudes from the through hole 46 to a limited part of the slidable contact surface 47 while using a conventional material such as an inexpensive synthetic resin. Since the conductivity between the ball stud 15 and the housing 16 is obtained using only the material, the increase in cost can be suppressed and the conductivity can be secured at a low cost.

  And since this ball joint 11 has completed the continuity between the ball stud 15 and the housing 16 constituting a part of the suspension arm, the stud joint 22 is simply connected to the knuckle and assembled to the suspension side. Electrical continuity with the knuckle side can be obtained, and the work of connecting with a connector or the like after assembly is not necessary, and the number of man-hours for assembling the vehicle can be reduced. That is, by using this ball joint 11, no electric wires from the vehicle body to the knuckle (wheel) can be required.

  Furthermore, by forming the conductor 51 with a (synthetic) resin containing a conductive material, for example, compared to the case where the conductor 51 is formed of metal or the like, the ball portion 21 and the conductor 51 are slidably contacted. Abrasion can be more reliably suppressed, and sliding reliability can be further improved.

  In particular, since a resin including a conductive material is generally expensive, the ball joint 11 can be configured at a lower cost by restricting the use of the resin including the conductive material to the conductor 51 only.

  Then, by providing the through hole 46 of the ball seat 17 at a position excluding the equator position E of the ball portion 21 of the sliding contact surface 47, the conductor 51 partially disposed in the through hole 46 is connected to the ball stud 15 from the ball stud 15. Hard to apply load. Therefore, the frictional force between the ball part 21 and the conductor 51 can be reduced, wear due to sliding between the ball part 21 and the conductor 51 can be more reliably suppressed, and the sliding reliability can be further improved.

  In the above embodiment, the ball joint 11 may be used for a tie rod end of a steering device.

  In addition, the housing 16 may be configured such that the housing portion is recessed in the bottom portion 33 of the inner chamber 31 formed in advance in the shape of a bottomed cylinder instead of the configuration in which the communication hole 34 is closed by the plug 37, for example.

  Further, the urging member is not limited to the coil spring 52, and for example, a cushion formed of an elastic synthetic resin or the like may be used.

  Further, the configuration is not limited to the configuration in which the conductor 51 is directly slidably contacted with the housing 16 and electrically connected to the housing 16. For example, the coil spring 52 is formed of a conductive member, and the coil spring 52 is interposed through the coil spring 52. The conductor 51 may be configured to be electrically connected to the housing 16.

  The above-described ball joint 11 may be used for each part such as a door mirror, a room mirror, and a wiper of a vehicle, or may be used for a part other than the vehicle, for example, a robot arm or a neck of a desk lamp. That is, the above-described ball joint 11 can be used in various electric devices having a movable part that operates three-dimensionally.

11 Ball joint
15 Ball stud as ball side member
16 Housing as ball receiving side member
17 Ball seat as bearing seat
21 Ball part
31 Interior room that is a ball receiving part
34 Communication hole that is a receiving part
46 Through hole
47 Sliding surface
51 Conductor
52 Coil spring as biasing member E Equatorial position

Claims (3)

A conductive ball side member provided with a ball portion and attached to the mounted portion;
A sliding contact surface for rotatably holding the ball portion, and an insulating bearing seat having a through hole communicating with the sliding contact surface;
A ball receiving portion for accommodating the ball portion together with the bearing seat, and a conductive ball receiving side member provided with an accommodating portion communicating with the through hole of the bearing seat accommodated in the ball receiving portion;
A conductor disposed at least in part in the through hole of the bearing seat and electrically connected to the ball receiving side member;
A ball joint, comprising: an urging member that is disposed in the housing portion of the ball receiving side member and presses the conductor against the ball portion. The ball joint according to claim 1, wherein the conductor is made of a resin containing a conductive material. The ball joint according to claim 1, wherein the through hole is provided at a position excluding the equator position of the ball portion of the sliding contact surface.

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