JP5495827B2 - Ball joint and ball joint device - Google Patents

Description

  The present invention relates to a ball joint capable of detecting wear of a bearing seat and a ball joint device including the same.

  2. Description of the Related Art Conventionally, this type of ball joint used for a suspension device or a steering device of a vehicle such as an automobile has a bottomed cylindrical socket and a ball seat which is a cylindrical bearing seat accommodated in the socket. And a ball stud having a ball portion slidably held on a sliding surface inside the ball seat and a stud portion protruding from the ball portion.

  In such a ball joint, the ball sheet gradually wears as the ball portion slides. Therefore, when the ball sheet wears more than a predetermined amount, replacement or the like is necessary. Therefore, in order to detect such wear of the ball sheet, the wear detection unit is electrically connected between the electrode embedded in the ball sheet or the conductive socket and the conductive ball stud. A connected configuration is known (see, for example, Patent Document 1 or 2). In these configurations, when the ball seat wears over a predetermined amount due to sliding of the ball portion, the circuit is closed by contact between the ball portion and the electrode or socket, and the wear detection portion can detect wear of the ball seat. It has become.

  However, in the case of such a configuration, for example, when a disconnection or the like has occurred in the circuit for some reason, the ball sheet remains open even if the ball sheet is worn over a predetermined amount. There is a problem that an observer may not be able to determine whether or not a predetermined amount of wear has occurred, that is, whether or not it is abnormal.

  Therefore, a conductive spring seat that contacts the ball portion and a coil spring that urges the ball portion upward via the spring seat are disposed inside the socket, and a conductive portion is provided in the center portion of the spring seat. A contact is attached to the lower end of the conductive member via a spring, and a tester is electrically connected between the bottom of the socket and the inspection terminal. A connected configuration is known (for example, see Patent Document 3). In this configuration, when the ball part is worn by a predetermined amount or more, the contact is separated from the bottom part of the socket by the coil spring, so that the circuit is opened, and the wear of the ball part can be detected by preventing the current from flowing to the tester. It has become. Therefore, with this configuration, for example, even when a disconnection or the like occurs in the circuit, it can be detected.

  However, in such a configuration, the configuration of the ball joint is complicated, and a space for moving the coil spring must be secured inside the socket, which makes it difficult to reduce the size.

JP 56-6911 A (2nd page, drawing) Japanese translation of PCT publication No. 2003-525404 (page 5-7, FIG. 1) Japanese Utility Model Publication No. 58-58114 (page 3-7, FIGS. 2 to 3)

  As described above, there is a demand for a ball joint device that can reliably detect system abnormalities including wear and disconnection of a ball seat or a ball portion, has a simple configuration, and can be miniaturized.

  The present invention has been made in view of the above points, and provides a ball joint that can be downsized without complicating the configuration and that can reliably detect a system abnormality, and a ball joint device including the ball joint. For the purpose.

The ball joint according to claim 1, wherein the ball joint has a cylindrical socket, a sliding surface inside, a cylindrical bearing seat accommodated in the socket, and has conductivity. A spherical ball portion whose outer peripheral surface is slidably held on the sliding surface, and a shaft-shaped stud portion that has conductivity and protrudes outward from the bearing seat and the socket. And a ball stud having electrical conductivity, arranged in contact with the ball portion at a position opposite to a load direction applied to the ball stud on the sliding surface of the bearing seat, And a conductive portion that is separated from the ball portion in a non-contact state by wear of a predetermined amount or more of the bearing seat due to a load applied to the stud.

  The ball joint according to claim 2 is the ball joint according to claim 1, wherein the ball stud has a stud portion protruding upward with respect to the ball portion, a compressive load is applied downward, and the conductive portion is It is arranged at the upper position on the sliding surface of the bearing seat.

  The ball joint according to claim 3 is the ball joint according to claim 1, wherein the ball stud has a stud portion protruding downward with respect to the ball portion, a tensile load is applied downward, and the conductive portion is It is arranged at the upper position on the sliding surface of the bearing seat.

  The ball joint device according to claim 4 is electrically connected between the ball joint according to any one of claims 1 to 3 and a stud portion and a conductive portion of the ball joint, and the ball between them. And a wear detector that detects the presence or absence of conduction through the ball portion of the joint.

According to the ball joint of claim 1, when the wear detecting portion is electrically connected between the conductive portion and the stud portion of the ball stud, the ball portion that is in contact when the bearing seat is worn by a predetermined amount or more. The conductive portion and the conductive portion are separated from each other in a non-contact state, and the conductive portion and the stud portion are electrically disconnected, and when the wire is disconnected, the wear detecting portion is electrically disconnected from the conductive portion or the stud portion. Therefore, it is possible to reduce the size without complicating the configuration, and it is possible to reliably detect system abnormalities such as wear and disconnection of the bearing seat exceeding a predetermined amount by the wear detector.

  According to the ball joint of claim 2, in addition to the effect of the ball joint of claim 1, a compressive load is applied downward to the ball stud in which the stud portion protrudes upward with respect to the ball portion. It is possible to cope with the compression type ball joint by arranging the conductive portion on the upper side of the sliding surface of the bearing seat.

  According to the ball joint according to claim 3, in addition to the effect of the ball joint according to claim 1, a tensile load is applied downward to the ball stud in which the stud portion protrudes downward with respect to the ball portion. The pulling type ball joint can be dealt with by arranging the conductive portion at an upper position on the sliding surface of the bearing seat.

  According to the ball joint device according to claim 4, the configuration is complicated by electrically connecting the wear detecting portion between the stud portion and the conductive portion of the ball joint according to any one of claims 1 to 3. The wear detection unit can reliably detect a system abnormality such as wear and disconnection of a predetermined amount or more of the bearing seat.

BRIEF DESCRIPTION OF THE DRAWINGS The ball joint apparatus provided with the ball joint of the 1st Embodiment of this invention is shown, (a) is the whole longitudinal cross-sectional view, (b) is sectional drawing to which one part was expanded. The ball joint apparatus provided with the ball joint of the 2nd Embodiment of this invention is shown, (a) is the whole longitudinal cross-sectional view, (b) is sectional drawing to which one part was expanded.

  The configuration of the first embodiment of the present invention will be described below with reference to FIG.

  In FIG. 1A, reference numeral 10 denotes a ball joint device, and this ball joint device 10 includes a ball joint 11 and a wear detection unit 12 electrically connected to the ball joint 11.

  The ball joint 11 is of a so-called compression type, and includes a socket 15 that is a housing, a ball sheet 16 that is a bearing seat accommodated in the socket 15, and a part of the ball seat 16 that slides. Ball stud 17 held so as to be movable (turnable), conductive portion 18 integrally attached to ball seat 16, and dust cover disposed from the outer peripheral surface of socket 15 to the outer peripheral surface of ball stud 17 19 and.

  The socket 15 has a bottomed cylindrical socket body 21 made of metal or the like, and an annular plug 22 made of metal or the like that is integrally fixed to the socket body 21.

  The socket body 21 includes an inner chamber 24 that accommodates the ball seat 16, and a socket opening 25 as an insertion opening that communicates the inner chamber 24 with the outside of the socket body 21 at the upper end. A bottom portion 26 that closes the inner chamber 24 is provided at the lower end portion. Further, the socket body 21 is formed with a cover fixing groove 28 in the circumferential direction on the outer peripheral surface on the upper end side for fixing the end of the dust cover 19. Further, the socket body 21 has a holding portion 31 on which the plug 22 is placed at the peripheral edge of the socket opening 25 in a stepped shape, and is caulked and deformed around the holding portion 31. A caulking fixing portion 32 that is a fixing portion for fixing the ball seat 16 and the ball stud 17 to the socket 15 is formed by fixing the plug 22. The socket body 21 is formed by, for example, (cold) forging or casting.

  Further, the plug 22 is caulked and fixed to the peripheral edge portion of the socket opening 25 by a caulking fixing portion 32 in a state of communicating with the socket opening 25.

  The ball sheet 16 has excellent wear resistance and elastic modulus such as polyester, polyacetal (POM), polyurethane (PU), polyamide (PA), nylon, polyetherketone (PEK), or polyetheretherketone (PEEK). It is made of a high synthetic resin or the like, and is formed in a cylindrical shape that can be fitted into the inner chamber 24 of the socket body 21. That is, the ball seat 16 has a spherical sliding surface 35 inside, and is coaxial with the socket opening 25 and the plug 22 of the socket body 21 at the upper end portion, continuously with the sliding surface 35. A first sheet opening 36 that is one sheet opening as a sheet insertion opening that communicates with the bottom of the socket body 21, and the other end facing the bottom 26 of the socket body 21 continuously with the sliding surface 35. A second sheet opening 37 which is a sheet opening is provided. Further, the ball seat 16 is reduced in diameter on the lower end side than on the upper end side, the second seat opening 37 is coaxial with the first seat opening 36, and more than the first seat opening 36. Also, the opening area is narrow. The ball sheet 16 may be formed by a single member, or may be configured by combining a plurality of members formed of synthetic resins having different characteristics, for example.

  The ball stud 17 is harder than the ball seat 16, and is made of, for example, steel, and has a spherical ball portion 41 having conductivity, and a shaft-shaped stud portion 42 having conductivity connected to the ball portion 41. Is integrated.

  For example, about 2/3 of the outer peripheral surface including the equator E1 (maximum diameter position) of the ball portion 41 is held on the sliding surface 35 of the ball seat 16 so as to be slidable (rotatable). That is, the ball portion 41 is accommodated in the inner chamber 24 of the socket 15 together with the ball seat 16. The ball portion 41 is formed such that the outer diameter of the equator E1, that is, the maximum outer diameter is substantially equal to the maximum inner diameter of the sliding surface 35 of the ball seat 16. That is, the shape of the outer peripheral surface of the ball portion 41 substantially matches the shape of the sliding surface 35 of the ball seat 16. Further, although not shown, for example, a lubricant (grease) is held between the outer peripheral surface of the ball portion 41 and the sliding surface 35 of the ball seat 16. Further, the center of the ball portion 41 is located on the central axis of the socket body 21 (socket 15) and is concentric with the sliding surface 35.

  The stud portion 42 is a portion to which a compressive load from the outside is applied in the direction of arrow A1 (downward), and protrudes upward with respect to the ball portion 41. The stud portion 42 is connected to the outer peripheral surface of the ball portion 41 coaxially with the ball center of the ball portion 41. For this reason, the axial direction of the stud part 42, that is, the axial center is along the central axis of the socket body 21 (socket 15) in an unloaded state, and is orthogonal (crossed) in front view to the equator E1 of the ball part 41. doing. Further, on the outer peripheral surface on the upper end side of the stud portion 42, a screw portion 44 that is screwed and fixed to an attached member (not shown) is formed. Further, the stud portion 42 is inserted through the openings 36 and 25 and the plug 22 and protrudes upward from the ball seat 16 and the socket 15. 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.

  The conductive portion 18 is an electrode formed in an annular shape with, for example, conductive synthetic resin, and the load direction applied to the ball stud 17 on the sliding surface 35 of the ball seat 16 (the direction of the arrow A1). Are arranged at the opposite position, that is, at the upper position. Further, the conductive portion 18 is substantially flush with the sliding surface 35 on the inner peripheral side, and constitutes a part of the sliding surface 35. Therefore, the inner peripheral side of the conductive portion 18 is in a normal state, that is, in a state where the ball seat 16 is not worn by a predetermined amount or more (predetermined thickness or more), and the stud portion 42 rather than the equator E1 of the ball portion 41. It is possible to contact (electrically connect) the outer peripheral surface of the side (upper side). The conductive portion 18 may be formed integrally with the ball sheet 16 by, for example, two-color molding, or a piece formed separately from the ball sheet 16 is attached to the ball sheet 16 integrally. May be.

  The dust cover 19 is also called a dust seal or a boot, and is formed in a flat cylindrical shape (a radial dimension is larger than the axial direction) by, for example, soft rubber or soft synthetic resin, and is an intermediate portion in the axial direction. Bulges outward. The dust cover 19 is attached and fixed so that the upper end side is pressed against the outer periphery of the stud portion 42 in the central axis direction, and the lower end side is attached and fixed to the cover fixing groove 28 of the socket 15. Accordingly, the dust cover 19 covers the socket opening 25 (the first sheet opening 36 of the ball seat 16) of the socket 15 regardless of the swinging of the ball stud 17, and dust inside the socket 15 or the ball seat 16 is covered. To prevent such intrusions.

  On the other hand, the wear detection unit 12 includes a DC power supply unit 48 that is a power supply unit, and a detector 49 that is electrically connected to the DC power supply unit 48.

  For example, the DC power supply unit 48 can be electrically connected to the outer peripheral surface below the threaded portion 44 of the stud portion 42 of the ball stud 17 on the high voltage side, and the low voltage side is connected to the socket 15 ( It is inserted into the socket body 21) and can be electrically connected to the conductive portion 18. Therefore, the wear detection circuit C1 is configured from the high voltage side of the DC power supply unit 48 through the stud portion 42, the ball portion 41, the conductive portion 18 and the detector 49 of the ball stud 17. The conductive portion 18 may be electrically connected to a terminal (not shown) or the like that protrudes outside the socket 15 and is electrically connected to the low voltage side of the DC power supply portion 48 via the detector 49.

  The detector 49 is a load such as a lamp that detects a current flowing through the wear detection circuit C1, and operates (lights) by power supply from the DC power supply unit 48 in a state where the wear detection circuit C1 is closed. For example, the operation stops (extinguishes) in a state where the wear detection circuit C1 is opened due to separation or disconnection between the conductive portion 18 and the ball portion 41 due to wear of the ball seat 16.

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

  When the ball joint device 10 is used, the wear detection unit 12 is electrically connected between the conductive portion 18 of the ball joint 11 and the stud portion 42 of the ball stud 17.

  When the ball seat 16 of the ball joint 11 is not worn more than a predetermined amount, the wear detection circuit C1 configured by the DC power supply unit 48, the stud unit 42, the ball unit 41, the conductive unit 18 and the detector 49 is closed. Therefore, a current flows through the wear detection circuit C1, and this current is detected by the detector 49.

  The ball seat 16 of the ball joint 11 is worn over time due to friction with the ball portion 41. In particular, the sliding surface 35 of the ball seat 16 is worn relatively larger on the load direction (arrow A1 direction) side applied to the ball stud 17 than at other positions. Therefore, as the wear progresses, the ball portion 41 rattles against the sliding surface 35 of the ball seat 16 as shown by the imaginary line in FIG. The direction of load applied to the ball stud 17 (arrow A1 direction) will gradually shift to the side opposite to the direction of load applied to the ball stud 17 (arrow A1 direction) when the wear of the ball seat 16 reaches a predetermined amount or more. The outer peripheral surface of the ball portion 41 is separated from the conductive portion 18 positioned at the position. Therefore, the wear detection circuit C1 is opened, and no current is detected by the detector 49. Similarly, when a disconnection occurs in the wear detection circuit C1, the wear detection circuit C1 is opened and no current is detected by the detector 49.

  As a result, the observer can detect that a system abnormality has occurred, such as the ball seat 16 being worn out by a predetermined amount or a disconnection.

  When such a system abnormality is detected, the ball joint 11 is replaced or the disconnected portion is electrically connected.

  As described above, in the first embodiment, when the wear detecting portion 12 is electrically connected between the conductive portion 18 and the stud portion 42 of the ball stud 17, the ball seat 16 is worn by a predetermined amount or more. In addition, the ball portion 41 and the conductive portion 18 are separated from each other, so that the conductive portion 18 and the stud portion 42 are electrically disconnected, and the wear detecting portion 12 with respect to the conductive portion 18 or the stud portion 42 when disconnected. Is electrically disconnected. For this reason, for example, the ball joint 11 (without complicating the configuration as in the conventional configuration that requires a coil spring for urging the ball seat in a direction opposite to the compression load and a contact for bringing the ball seat into contact with the socket, etc. The ball joint device 10) can be reduced in size, and system abnormalities such as wear and disconnection of the ball seat 16 exceeding a predetermined amount can be reliably detected by the wear detector 12.

  In other words, in a conventional energization confirmation type circuit that detects anomalies by energizing by closing the ball seat due to wear over a predetermined amount, etc., if a disconnection or the like occurs for some reason before the ball seat wears, Since the circuit is opened, abnormalities such as wear or disconnection of the ball seat cannot be detected, whereas in the first embodiment, the DC power supply 48, the stud 42, the ball 41, the conductive The wear detection circuit C1 configured by the unit 18 and the detector 49 is an insulation confirmation type circuit that detects an abnormality by being opened due to wear of a predetermined amount or more of the ball sheet 16, and so on. Not only wear, but also system abnormalities such as other electrical failures that open the wear detection circuit C1 can be reliably detected, providing a safer and more reliable configuration. It can be.

  Also, for example, when the conductive portion is arranged on the same side as the load direction applied to the ball stud, even if the ball seat is worn over a predetermined amount, the ball portion is pressed against the conductive portion by the load applied to the ball stud. While the wear detection circuit does not open and it is not easy to detect wear exceeding a predetermined amount of the ball seat, in the first embodiment, in the direction of load applied to the ball stud 17 (arrow A1 direction). On the other hand, since the conductive portion 18 is arranged on the opposite side, when the ball seat 16 is worn by a predetermined amount or more, the ball portion 41 is immediately separated from the conductive portion 18 and the wear detection circuit C1 is Thus, the wear of the ball seat 16 can be reliably detected by the wear detector 12.

  Specifically, the conductive portion 18 is connected to the ball seat 16 with respect to the compression type ball joint 11 in which a compressive load is applied downward to the ball stud 17 in which the stud portion 42 protrudes upward with respect to the ball portion 41. This can be dealt with by placing the sliding surface 35 at the upper position.

  Next, a second embodiment will be described with reference to FIG. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, a so-called tension type ball joint 51 is provided in place of the ball joint 11 of the first embodiment.

  That is, as shown in FIG. 2A, the ball joint 51 includes a socket 55 as a housing, a ball sheet 56 as a bearing seat accommodated in the socket 55, and a part of the ball seat 56. Ball stud 57 held slidably (rotatable), conductive portion 58 integrally attached to ball seat 56, and dust disposed from the outer peripheral surface of socket 55 to the outer peripheral surface of ball stud 57 And a cover 59.

  The socket 55 includes a cylindrical socket body 61 made of metal or the like, and a disk-like plug 62 made of metal or the like that is fixed to the socket body 61 integrally.

  The socket body 61 is provided with an inner chamber 64 for accommodating the ball seat 56 therein, and at the lower end is one opening as an insertion opening that communicates the inner chamber 64 with the outside of the socket body 61. A first socket opening 65 is provided, and a second socket opening 66 which is the other opening serving as a communication opening for communicating the inner chamber 64 with the outside of the socket body 61 is provided at the upper end. Further, the socket main body 61 is formed with a cover fixing groove 68 in the circumferential direction for fixing the end of the dust cover 59 on the outer peripheral surface on the lower end side. Furthermore, the socket body 61 has a holding portion 71 on which the plug 62 is placed in a stepped portion at a continuous portion between the inner chamber 64 and the second socket opening 66, and around the holding portion 71. A caulking fixing portion 72 is formed as a fixing portion for fixing the ball seat 56 and the ball stud 57 to the socket 55 by fixing the plug 62 by caulking deformation. The socket body 61 is formed by, for example, (cold) forging or casting.

  The first socket opening 65 is formed so as to gradually increase in diameter from the inner chamber 64 side toward the lower end side.

  Further, the plug 62 is fixed by caulking and fixing by the caulking fixing portion 72 in a state where the peripheral portion is held by the holding portion 71, thereby closing the upper end side of the inner chamber 64, that is, the second socket opening 66. .

  The ball sheet 56 has excellent wear resistance and elastic modulus such as polyester, polyacetal (POM), polyurethane (PU), polyamide (PA), nylon, polyetherketone (PEK), or polyetheretherketone (PEEK). It is made of a high synthetic resin and is formed in a cylindrical shape that can be fitted into the inner chamber 64 of the socket body 61. That is, the ball sheet 16 has a spherical sliding surface 75 inside, and a sheet that communicates with the first socket opening 65 of the socket body 61 continuously at the lower end portion of the ball seat 16. A first sheet opening 76 that is one sheet opening serving as an insertion opening is provided, and further, a sheet communication that communicates with the second socket opening 66 of the socket body 61 continuously with the sliding surface 75 at the upper end. A second sheet opening 77 which is the other sheet opening as the opening is provided. Note that the ball sheet 56 may be formed by a single member, or may be configured by combining a plurality of members formed of, for example, synthetic resins having different characteristics.

  The ball stud 57 is made of, for example, steel, and integrally includes a spherical ball portion 81 having conductivity and a shaft-shaped stud portion 82 having conductivity connected to the ball portion 81.

  For example, about 2/3 of the outer peripheral surface including the equator E2 (maximum diameter position) is held on the sliding surface 75 of the ball seat 56 so that the ball portion 81 can slide (turn). That is, the ball part 81 is accommodated in the inner chamber 24 of the socket 55 together with the ball seat 56. The ball portion 81 is formed such that the outer diameter dimension of the equator E2, that is, the maximum outer diameter dimension is substantially equal to the maximum inner diameter dimension of the sliding surface 75 of the ball seat 56. That is, the shape of the outer peripheral surface of the ball portion 81 substantially matches the shape of the sliding surface 75 of the ball seat 56. Further, although not shown, for example, a lubricant (grease) is held between the outer peripheral surface of the ball portion 81 and the sliding surface 75 of the ball seat 56. Further, the ball center which is the center of the ball portion 81 is located on the central axis of the socket body 61 (socket 55) and is arranged concentrically with the sliding surface 75.

  The stud portion 82 is a portion where a tensile load from the outside is applied in the direction of arrow A2 (downward), a round shaft-shaped stud portion main body 85, and a disc fixed integrally to the outer periphery of the stud portion main body 85 And a hook-like collar portion 86. The stud portion 82 may be formed integrally with the ball portion 81, or may be formed separately from the ball portion 81 and then integrated with the ball portion 81 by welding or the like.

  The stud body 85 is connected to the outer peripheral surface of the ball portion 81 coaxially with the ball center of the ball portion 81. Therefore, the axial direction of the stud body 85 (stud portion 82), that is, the axial center is along the central axis of the socket body 61 (socket 55) in the unloaded state, and is in front of the equator E2 of the ball 81. It is orthogonal (intersect) in view. Further, on the outer peripheral surface on the lower end side of the flange portion 86 of the stud portion main body 85, a screw portion 88 that is screwed and fixed to an attached member (not shown) is formed. Further, the stud body 85 is inserted through the openings 76 and 65 and protrudes downward from the ball seat 56 and the socket 55.

  The flange portion 86 forms a seating surface that comes into contact with the attached member when the screw portion 88 is fixed to the attached member by screwing, and has a larger diameter than the stud body 85. .

  In addition, the conductive portion 58 is an electrode formed in an annular shape with, for example, a conductive synthetic resin, and the load direction applied to the ball stud 57 on the sliding surface 75 of the ball seat 56 (the direction of the arrow A2). Are arranged at the opposite position, that is, at the upper position. Further, the conductive portion 58 is substantially flush with the sliding surface 75 on the inner peripheral side, and constitutes a part of the sliding surface 75. Therefore, the inner peripheral side of the conductive portion 58 is in a normal state, that is, in a state where the ball seat 56 is not worn by a predetermined amount or more (predetermined thickness or more), and the stud portion 82 rather than the equator E2 of the ball portion 81. It is possible to contact (electrically connect) the outer peripheral surface of the side (upper side). The conductive portion 58 may be formed integrally with the ball sheet 56 by, for example, two-color molding, or a piece molded separately from the ball sheet 56 is attached to the ball sheet 56 integrally. May be.

  The dust cover 59 is also called a dust seal or a boot, and is formed in a flat cylindrical shape (a larger dimension in the radial direction than the axial direction) by, for example, soft rubber or soft synthetic resin, and an intermediate portion in the axial direction. Bulges outward. The dust cover 59 is attached and fixed so that the lower end side is pressed against the outer periphery of the stud portion 82 in the center axis direction, and the upper end side is attached and fixed to the cover fixing groove 68 of the socket 55. Therefore, the dust cover 59 covers the first socket opening 65 of the socket 55 (the first sheet opening 76 of the ball sheet 56) regardless of the swing of the ball stud 57, and enters the socket 55 or the ball sheet 56. Prevents the intrusion of dust.

  On the other hand, the wear detection unit 12 is inserted into the socket 55 (socket body 61), for example, on the high voltage side of the DC power supply unit 48 and can be electrically connected to the conductive unit 58. The low pressure side can be electrically connected to the outer peripheral surface of the stud portion 82 of the ball stud 57 in the vicinity of the flange portion 86 via the detector 49. Therefore, the wear detection circuit C2 is configured from the high voltage side of the DC power supply unit 48 through the conductive portion 58, the ball portion 81, the stud portion 82, and the detector 49 of the ball stud 57. For this reason, the detector 49 operates (lights up) by power supply from the DC power supply unit 48 in a state where the wear detection circuit C2 is closed, and for example, the conductive unit 58 and the ball unit due to wear of the ball seat 56 The operation stops (turns off) in a state where the wear detection circuit C2 is opened due to separation from the terminal 81 or disconnection.

  That is, in the second embodiment, when the ball joint device 10 is used, the wear detector 12 is electrically connected between the conductive portion 58 of the ball joint 51 and the stud portion 82 of the ball stud 57. Connecting.

  When the ball seat 56 of the ball joint 51 is not worn more than a predetermined amount, the wear detection circuit C2 configured by the DC power supply unit 48, the conductive unit 58, the ball unit 81, the stud unit 82, and the detector 49 is closed. Therefore, a current flows through the wear detection circuit C2, and this current is detected by the detector 49.

  The ball seat 56 of the ball joint 51 is worn over time due to friction with the ball portion 81. In particular, the sliding surface 75 of the ball seat 56 is worn relatively larger on the load direction (arrow A2 direction) side applied to the ball stud 57 than at other positions. Therefore, as wear progresses, the ball portion 81 rattles against the sliding surface 75 of the ball seat 56 as indicated by the imaginary line in FIG. When the wear of the ball seat 56 reaches a predetermined amount or more, the load direction applied to the ball stud 57 (arrow A2 direction) is opposite to the load direction applied to the ball stud 57 (arrow A2 direction). The outer peripheral surface of the ball portion 81 is separated from the conductive portion 58 located at the position. Accordingly, the wear detection circuit C2 is opened, and no current is detected by the detector 49. Similarly, when a disconnection occurs in the wear detection circuit C2, the wear detection circuit C2 is opened and no current is detected by the detector 49.

  As a result, the observer can detect that a system abnormality has occurred, such as the ball seat 56 being worn out by a predetermined amount or a disconnection.

  When such a system abnormality is detected, the ball joint 51 is replaced or the disconnected portion is electrically connected.

  As described above, according to the second embodiment, when the wear detector 12 is electrically connected between the conductive portion 58 and the stud portion 82 of the ball stud 57, the ball seat 56 is worn by a predetermined amount or more. When this occurs, the ball portion 81 and the conductive portion 58 are separated from each other, so that the conductive portion 58 and the stud portion 82 are electrically disconnected. Part 12 is electrically disconnected. For this reason, for example, the ball joint 51 (ball joint device 10) without complicating the configuration as in the conventional configuration that requires a coil spring that biases the ball seat along the load and a contact that contacts the ball seat with the socket. The wear detection unit 12 can reliably detect system abnormalities such as wear and disconnection of the ball seat 56 exceeding a predetermined amount.

  In other words, in a conventional energization confirmation type circuit that detects anomalies by energizing by closing the ball seat due to wear over a predetermined amount, etc., if a disconnection or the like occurs for some reason before the ball seat wears, Since the circuit is opened, abnormalities such as wear or disconnection of the ball seat cannot be detected, whereas in the second embodiment, the DC power supply unit 48, the conductive unit 58, the ball unit 81, the stud The wear detection circuit C2 constituted by the part 82 and the detector 49 is an insulation confirmation type circuit that detects an abnormality by being opened due to wear of a predetermined amount or more of the ball sheet 56, thereby Not only wear but also system abnormalities such as other electrical faults that open the wear detection circuit C2 can be reliably detected, providing a safer and more reliable configuration. It can be.

  Also, for example, when the conductive portion is arranged on the same side as the load direction applied to the ball stud, even if the ball seat is worn over a predetermined amount, the ball portion is pressed against the conductive portion by the load applied to the ball stud. While the wear detection circuit does not open and it is not easy to detect wear over a predetermined amount of the ball seat, in the second embodiment, in the load direction (in the direction of arrow A2) applied to the ball stud 57 On the other hand, since the conductive portion 58 is disposed on the opposite side, when wear of a predetermined amount or more occurs in the ball seat 56, the ball portion 81 is immediately separated from the conductive portion 58 and the wear detection circuit C2 is Thus, the wear detection unit 12 can reliably detect wear of the ball seat 56.

  Specifically, the conductive portion 58 is connected to the ball seat 56 with respect to the pull-type ball joint 51 in which a tensile load is applied downward to the ball stud 57 in which the stud portion 82 protrudes downward with respect to the ball portion 81. This can be dealt with by placing the sliding surface 75 at the upper position.

  In the second embodiment, the conductive portion 58 may be electrically connected to a terminal (not shown) that protrudes outside the socket 55 and is electrically connected to the high-voltage side of the DC power supply portion 48. Good.

  Further, in each of the above embodiments, the details of the ball joints 11 and 51 are not limited to the above configuration.

  Further, the wear detection unit 12 can use any configuration as long as it can detect the presence or absence of conduction through the ball portion 41 of the ball joint 11 between the stud portion 42 and the conductive portion 18.

10 Ball joint device
11, 51 Ball joint
12 Wear detector
15, 55 socket
16, 56 Ball seat as a bearing seat
17,57 Ball stud
18, 58 Conductive part
35, 75 Sliding surface
41, 81 Ball
42, 82 Stud section

Claims (4)

A cylindrical socket,
A cylindrical bearing seat having a sliding surface inside and housed in the socket;
A spherical ball portion having conductivity and having an outer peripheral surface slidably held on the sliding surface of the bearing seat, and having conductivity and projecting from the ball portion, the bearing seat and the A ball stud provided with a shaft-shaped stud portion protruding outward from the socket;
The bearing has electrical conductivity, is disposed in contact with the ball portion at a position opposite to a load direction applied to the ball stud on the sliding surface of the bearing seat, and is caused by a load applied to the ball stud. A ball joint, comprising: a conductive portion that is separated from the ball portion in a non-contact state due to wear of a predetermined amount or more of the seat. The ball stud protrudes upward with respect to the ball part, and a compressive load is applied downward.
The ball joint according to claim 1, wherein the conductive portion is disposed at an upper position on the sliding surface of the bearing seat. The ball stud protrudes downward with respect to the ball part, and a tensile load is applied downward.
The ball joint according to claim 1, wherein the conductive portion is disposed at an upper position on the sliding surface of the bearing seat. A ball joint according to any one of claims 1 to 3,
A ball joint device comprising: a wear detection unit that is electrically connected between a stud part and a conductive part of the ball joint and detects the presence or absence of conduction between them.

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