JP2011012728A - Ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball joint which prevents an increase in assembly man-hours and component management man-hours, preventing incorrect setting of an elastic member on a predetermined position in a socket due to variations in assembly work, not causing a clearance and relative positional displacement between a ball seat and the ball joint, also prevents the operation torque instability of a ball stud, and not causing a decrease in operation torque due to a prolonged use.SOLUTION: This ball joint includes the ball stud having a spherical portion, a ball seat fitting and holding the spherical portion, a spring seat formed on the bottom of the ball seat and pressing upward a spring force, and the socket. The spring seat and ball seat are incorporated in the socket. The spherical portion of the ball stud is fitted into the lumen of the ball seat. A soft synthetic resin secondary component functioning as the spring seat is integrally formed with a hard synthetic resin primary component functioning as the ball seat.

Description

  The present invention relates to a ball joint used for an automobile suspension or the like.

  Conventionally, a ball joint used for an automobile suspension or the like includes a ball stud having a spherical portion at the lower end, a synthetic resin ball seat that fits and holds the spherical portion of the ball stud, and press-fits the ball seat. It consists of sockets.

  To assemble a ball joint of this type, press the ball stud and ball seat into the socket, and then squeeze and deform the outer periphery near the opening of the socket inward, so that the upper part of the ball seat is Press and fix to the spherical part. For this reason, the manufacturing error of each part has a big influence on the operating torque of a ball stud, and there existed a problem that the product produced variation.

  Therefore, as conventional techniques made to eliminate such inconvenience, the following Patent Documents 1 and 2 are referred to.

  The ball joint described in Patent Document 1 includes an elastic member that gives a preload to a ball seat made of hard synthetic resin, and in a state where the spherical portion of the ball stud, the ball seat, and the elastic member are incorporated in the socket, The opening is deformed inward to surround the spherical portion of the ball stud.

  In addition, the ball joint described in Patent Document 2 compresses the elastic sheet in the socket so as to press the ball sheet against the ball portion of the ball stud, and compresses the elastic sheet and holds it in the socket. It is set as the structure provided with the end cover to be made.

  With the configurations of Patent Documents 1 and 2 described above, a predetermined sliding torque (rotation torque around the shaft) and swinging torque can be applied to the ball stud, and the load during use can be absorbed and relaxed. .

No. 1-7848 Japanese Utility Model Publication No. 5-37049

  However, in the structures of Patent Documents 1 and 2 described above, since the ball seat and the elastic member are separated, the number of assembling steps when the spherical portion of the ball stud, the ball seat, and the elastic member are assembled in the socket increases. At the same time, since the number of parts increases, there is an inconvenience that the number of parts management man-hours increases.

  In addition, due to variations in assembly work, the elastic member may not be seated accurately at a predetermined position in the socket, or a gap or a relative position deviation may occur between the ball seat and the operating torque of the ball stud may be reduced. There is a risk that the operating torque may be reduced due to stability or long-term use.

  Therefore, the present invention has been made to solve the above-described problems, and does not increase the number of ball joint assembling man-hours and part management man-hours. It does not sit correctly at the specified position, does not cause a gap or a relative position gap between the ball seat, the operating torque of the ball stud becomes unstable, and the operating torque does not increase due to long-term use. An object of the present invention is to provide a ball joint that does not cause a drop.

  In order to solve the above problems, a ball joint according to claim 1 of the present invention includes a ball stud having a spherical portion at a lower end, and a ball seat having a lumen portion in which the spherical portion of the ball stud is fitted and held. A spring seat for biasing upward spring force to the bottom of the ball seat, and a substantially cylindrical socket. The spring seat and the ball seat are assembled in the socket, and the ball seat is inserted into the inner cavity of the ball seat. In a ball joint fitted with a spherical portion of a stud, a secondary part made of a soft synthetic resin functioning as a spring seat is integrally formed with a primary part made of a hard synthetic resin functioning as a ball seat. And

  According to a second aspect of the present invention, when the secondary part is integrally formed with the primary part, the ball joint according to the first aspect is provided with a plurality of slits formed at the bottom of the primary part. A grease groove is formed when the soft synthetic resin material of the part enters.

  The ball joint according to claim 3 of the present invention is the ball joint according to claim 1 or 2, wherein a plurality of recesses are provided on the circumference of the outer surface of the primary part, and the soft synthetic resin material of the secondary part is the primary. By flowing into each recess of the side part, the secondary part is firmly fused to the primary side part.

  The ball joint according to claim 4 of the present invention is the ball joint according to claim 1, 2 or 3, wherein a linear protrusion having a length equal to or greater than the thickness of the secondary part is provided at the bottom of the primary part. The protrusion entering the secondary part is molded in a curved state by abutting against the molding die of the secondary part.

  Furthermore, a ball joint according to a fifth aspect of the present invention is the ball joint according to the first, second, third, or fourth aspect, wherein a plurality of slits in the meridian direction are provided at the bottom of the primary side part, and the inner circumference of the primary side part is provided. A circumferential groove is provided on the outer periphery, and the bottom part of the primary part presses the lower part of the spherical part of the secondary part under the spring reaction force of the elastic deformation of the secondary part.

  According to the present invention described above, the secondary part functioning as the spring seat is integrally formed with the primary part functioning as the ball seat, so that the relative positions of both are accurately positioned and firmly fused. Therefore, there is no deviation due to load when used as an elastic member of a ball joint, and both of the two demands that are difficult to achieve both absorption of manufacturing errors of each part and accurate application of ball stud operating torque are satisfied. It becomes possible.

  Furthermore, since the primary part and the secondary part are integrally formed, the assembly man-hours for assembly into the socket together with the ball stud spherical portion are not increased, and the number of parts is reduced. Management man-hours can be reduced.

  In addition, the lower surface of the secondary part is pressed against the socket surface and elastically deforms, and the elastic deformation absorbs manufacturing errors of the respective parts, and the spring reaction force of the elastic deformation causes the bottom of the primary part to move to the ball. Since the lower portion of the spherical portion of the stud is pressed, an appropriate operating torque can be applied to the ball stud.

  Further, it is possible to prevent a decrease in torque due to long-term use due to the spring reaction force of the elastic deformation of the secondary part.

It is sectional drawing which shows the 1st Example of this invention, (a) shows the state before the assembly | attachment of a ball stud, (b) shows the state after the assembly | attachment of a ball stud. It is sectional drawing of the integrally molded product formed by integrally molding the secondary side part to the primary side part which concerns on the Example of this invention, (a) is a top view of an integrally molded product, (b) is (c) ) Is a cross-sectional view taken along line A-B in FIG. It is sectional drawing which shows the 2nd Example of this invention.

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

  As shown in FIGS. 1 (a) and 1 (b), the overall configuration of the ball joint 1 relating to the first embodiment of the present invention includes a ball stud 2 having a spherical portion 2a at the lower end, and a spherical portion of the ball stud 2. A primary part 3 having a lumen 3a for fitting and holding 2a, a secondary part 4 for biasing an upward spring force against the bottom of the primary part 3, and a socket 5. It has.

  As shown in FIG. 1A, the socket 5 is formed in a substantially cylindrical shape having an outer peripheral portion 5a, a bottom portion 5b, and an upper opening 5c. Further, a stepped portion 8 that protrudes inward in the vicinity of the lower end of the upper large-diameter portion 7 is formed on the inner periphery of the socket 5, and a tapered receiving surface 10 that is narrowed from the stepped portion 8 to the bottom surface 9 is formed. ing. The stepped portion 8 has an entire circumference which is substantially the middle position between the equator portion and the lower end portion of the spherical portion 2a when the integrally molded product 6 fitted with the spherical portion 2a of the ball stud 2 is assembled in the socket 5. It is formed to protrude.

  In such a configuration, in this embodiment, the primary part 3 that functions as a so-called ball seat is formed of a hard synthetic resin material, while the secondary part 4 that functions as a so-called spring seat is formed of a soft synthetic resin material. As shown in FIGS. 1 (a), (b) or FIGS. 2 (a), (b), (c) An integrally molded product 6 of the primary part 3 and the secondary part 4 is obtained.

  Further, the primary part 3 has a lumen portion 3a for fitting the spherical portion 2a of the ball stud 2 inside the trunk portion 11 fitted in the large diameter portion 7 of the socket 5 shown in FIG. And a shoulder 12 that contacts the step 8 of the socket 5 on the outer periphery of the lower end of the body 11. Further, as shown in FIGS. 2A and 2B, a plurality of (four in this embodiment) slits 13 in the meridian direction are formed in the bowl-shaped bottom portion 14 provided below the shoulder portion 12. , 13... Are formed, and an inner circumferential groove 15 a and an outer circumferential groove 15 b are formed in the inner and outer circumferential directions in the vicinity of the shoulder portion 12.

  Further, a plurality of (four in the present embodiment) grease grooves 16, 16... Are formed in the inner cavity 3 a of the primary part 3 toward the meridian direction, and the lower ends of the grease grooves 16, 16. The plurality of slits 13, 13... Provided in the bottom portion 14 of the primary side component 3 communicate with a grease reservoir 17 formed through the center of the bottom portion 14.

  On the other hand, as shown in FIG. 2B, the secondary side component 4 matches the upper surface 18 that matches the lower surface of the bottom portion 14 of the primary side component 3 and the taper receiving surface 10 and the bottom surface 9 of the socket 5. A substantially dish-like shape having a lower surface 19 is formed, and a plurality of projections 20, 20... That elastically contact the lower surface 19 with respect to the taper receiving surface 10 of the socket 5 are projected radially. A grease reservoir 21 is also formed at the center of the secondary part 4.

  In order to integrally form the soft synthetic resin secondary part 4 on the hard synthetic resin primary part 3 described above, “different material molding”, that is, “two-material molding” or “two-color molding” is well known. It can be implemented by using the molding method. As an integral molding method, in addition to the above, for example, the secondary side component 4 made of soft synthetic resin may be integrally molded with the primary side component 3 made of hard synthetic resin by insert molding.

  As described above, in the integrally molded product 6 in which the secondary side part 4 made of the soft synthetic resin is integrally molded with the primary side part 3 made of the hard synthetic resin, the bottom part 14 of the primary side part 3 is provided in the meridian direction. The plurality of slits 13, 13... And the inner circumferential groove 15 a and the outer circumferential groove 15 b provided in the circumferential direction on the inner and outer sides in the vicinity of the shoulder portion 12 are formed. In response to the spring reaction force due to the deformation, the bottom part of the primary side member 3 acts to press the lower part of the spherical part 2 a of the ball stud 2.

  When the secondary part 4 is integrally formed with the primary part 3 as described above, the soft synthetic resin material of the secondary part 4 enters the slits 13, 13... Of the bottom part 14 of the primary part 3. The grease grooves 22, 22 ... are formed. Since each grease groove 22 is connected to the grease grooves 16, 16... Of the primary side part 3, the spherical portion 2 a of the ball stud 2 can be well lubricated. Further, since the inner peripheral groove 15a of the primary part 3 is connected to the grease grooves 16, 16,... Of the primary part 3, the spherical portion 2a of the ball stud 2 can be lubricated throughout.

  Further, as shown in FIG. 2 (c), by providing a plurality of recesses 23, 23... On the circumference of the outer surface of the primary side part 3, the secondary side part 4 is integrally formed when the secondary side part 4 is integrally formed. Since the soft synthetic resin material of the secondary part 4 flows into each of the plurality of recesses 23 of the primary part 3 (this flowing part is referred to as a flow part 24), the primary part 3 and the secondary part 4 are Firmly fused.

  In this embodiment, a linear protrusion 27 is provided on the bottom 14 of the primary side component 3. Since the protrusion 27 has a length that is equal to or greater than the thickness of the secondary part 4, the linear protrusion 27 that has entered the secondary part 4 is curved by abutting against the mold of the secondary part 4. In this state, the primary side component 3 and the secondary side component 4 are firmly bonded.

  Further, a plurality of (in this embodiment, eight) radial recesses 25, 25... Are provided on the lower surface 19 of the secondary side component 4, and when the lower surface 19 of the secondary side component 4 is pressed against the socket 5 surface. It is easy to elastically deform.

  Further, when the secondary part 4 is molded, the primary part 3 is fixed by a plurality of pins, so that the bottom part of the secondary part 4 has a plurality ( In this embodiment, four pin holes 26, 26... Are provided.

  The spherical portion 2a of the ball stud 2 is fitted in the lumen 3a of the primary part 3 of the integrally molded product 6 formed as described above, and as shown in FIG. The ball joint 1 in which the spherical deforming portion 5d surrounds the spherical portion 2a of the ball stud 2 can be configured by drawing and deforming the upper opening 5c side of the outer peripheral portion 5a inward.

  Thus, when the body part 11 of the primary part 3 is pressed against the spherical part 2a by the deformation of the socket 5, the shoulder part 12 at the lower end of the body part 11 comes into pressure contact with the step part 8 of the socket 5. It becomes possible to prevent the thickness of the body part 11 from escaping in the direction of the bottom part 14 by using the part 8 as a stopper. Further, the inner cavity portion 3 a and the spherical portion 2 a of the trunk portion 11 are joined with an appropriate tightening margin determined by the restriction of the socket 5. Further, since the secondary part 4 is made of a soft synthetic resin, when the spherical part 2 a is pressed downward through the bottom part 14 of the primary part 3, the plurality of protrusions 20 are tapered on the socket 5. It is pressed against the receiving surface 10 to undergo compression elastic deformation, and the elastic deformation absorbs manufacturing errors of each component, and the spring reaction force causes the bottom portion 14 of the primary side component 3 to move below the spherical portion 2a of the ball stud 2. It is possible to apply a suitable preload to the ball stud 2 by pressing the portion.

  In the ball joint 1 configured as described above, a load in the pulling direction is input to the ball stud 2 in a use state. Therefore, when the upper part of the spherical part 2 a of the ball stud 2 strongly presses the upper part of the trunk part 11 of the primary part 3, the shoulder part 12 at the lower end of the trunk part 11 is received by the step part 8 of the socket 5. Therefore, there is no escape of the wall thickness in the direction of the bottom portion 14, and it is possible to improve the support strength against the load in the ball stud pulling direction.

  Note that a part in which the secondary part 4 is integrally formed with the primary part 3 as in the present embodiment is deformed inwardly from the upper opening 5c of the socket 5 as in the present embodiment, and the ball stud 2 has a spherical shape. In addition to being used for the ball joint 1 of the type surrounding the portion 2a, the bottom of the secondary part 4 is pushed with the end cover, and the end cover is caulked and fixed to the socket 5 for use with the type of ball joint 1 configured. Can exhibit the same effect.

  FIG. 3 shows a second embodiment of the present invention. In this example, the socket 5 is formed in a substantially cylindrical shape with the upper and lower parts open, and the upper part of the inner periphery of this cylindrical shape is formed in a spherical shape slightly squeezed inward, and the primary part of the integrally molded product 6 After the spherical portion 2 a of the ball stud 2 is fitted into the inner cavity portion 3 a of the ball 3, the ball stud 2 and the integrally molded product 6 are pushed into the socket 5 upward from the lower opening of the socket 5 and the secondary side component 4 The end plate 28 is joined to the lower side of the bottom portion and the peripheral edge of the lower opening of the socket 5 is caulked to fix the outer peripheral portion of the end plate 28 with the caulking portion 29 to form a ball joint 1 ′. The present invention is applied.

  In such a configuration, the primary part 3 that functions as a so-called ball seat is formed of a hard synthetic resin material, while the secondary part 4 that functions as a so-called spring sheet is formed of a soft synthetic resin material. By forming the secondary part 4 integrally with the secondary part 3, as shown in FIGS. 1 (a) and (b) or FIGS. 2 (a), (b) and (c), the primary part 3 The structure for obtaining the integrally molded product 6 with the secondary part 4 is the same as in the first embodiment.

  In this second embodiment, the end plate 28 is formed in a substantially dish shape having a central bottom surface 28a and a taper receiving surface 28b extending upward from the outer periphery thereof, and the end plate 28 is attached to the bottom of the secondary part 4 at the bottom. The difference from the first embodiment is that the bottom surface 28a and the taper receiving surface 28b of the plate 28 are substantially aligned.

  The spherical portion 2a of the ball stud 2 is fitted into the lumen 3a of the primary side part 3 of the integrally molded product 6 configured as described above. Thus, the integrally molded product 6 incorporating the ball stud 2 is inserted into the inner peripheral surface upward from the lower opening of the socket 5. Then, the end plate 28 is applied from below and is fixed by caulking.

  By this caulking, the integrally molded product 6 is pressed upward, and the upper part of the body part 11 of the primary side part 3 having the shape shown by the chain line is pressed against the spherical part of the upper part of the inner peripheral surface of the socket 5. Deforms inward and presses against the spherical portion 2a. Further, the plurality of protrusions 20 of the secondary side component 4 are pressed against the bottom surface 28a and the taper receiving surface 28b of the end plate 28 to be compressed and elastically deformed, and this elastic deformation absorbs manufacturing errors of each component and the spring reaction thereof The bottom 14 of the primary part 3 is pressed against the lower part of the spherical portion 2a of the ball stud 2 by force, and an appropriate preload can be applied to the ball stud 2.

  The present invention can be used as a ball joint used in a steering mechanism, a suspension mechanism, etc. of an automobile, and does not increase the man-hours for assembling the ball joints or the man-hours for managing the parts. Due to this, the elastic member does not sit accurately at a predetermined position in the socket, there is no gap or relative position deviation between the ball seat, and the operation torque of the ball stud becomes unstable, It can be used as a ball joint that does not cause a decrease in operating torque due to long-term use.

DESCRIPTION OF SYMBOLS 1, 1 'Ball joint 2 Ball stud 2a Spherical part 3 Primary part 3a Lumen part 4 Secondary part 5 Socket 5a Outer peripheral part 5b Bottom part 5c Upper opening part 5d Diaphragm | deformation part 6 Integrated molded article 7 Large diameter part 8 Step portion 9 Bottom surface 10 Tapered receiving surface 11 Body portion 12 Shoulder portion 13 Slit 14 Bottom portion 15a Inner circumferential groove 15b Outer circumferential groove 16 Grease groove 17 Grease reservoir 18 Upper surface 19 Lower surface 20 Projection 21 Grease reservoir 22 Grease groove 23 Recess 24 Inflow portion 25 Radial recess 26 Pin hole 27 Linear protrusion 28 End plate 28a Bottom surface 28b Taper receiving surface 29 Caulking portion

Claims (5)

A ball stud having a spherical portion at the lower end, a ball seat having a lumen for fitting and holding the spherical portion of the ball stud, and a spring seat for biasing upward spring force to the bottom of the ball seat; Rigid synthetic resin that functions as a ball seat in a ball joint comprising a cylindrical socket, a spring seat and a ball seat incorporated in the socket, and a ball stud spherical portion fitted in the inner cavity of the ball seat A ball joint formed by integrally molding a secondary side part made of a soft synthetic resin functioning as a spring seat on a primary side part made of a metal. When the secondary part is integrally formed with the primary part, a grease groove is formed by the soft synthetic resin material of the secondary part entering the plurality of slits formed at the bottom of the primary part. The ball joint according to claim 1. A plurality of concave portions are provided on the circumference of the outer side surface of the primary side component, and the soft synthetic resin material of the secondary side component flows into each concave portion of the primary side component, so that the secondary side component is placed on the primary side component. 3. The ball joint according to claim 1, wherein the ball joint is firmly fused. A linear protrusion having a length equal to or greater than the thickness of the secondary part is provided at the bottom of the primary part, and the protrusion entering the secondary part hits the molding die of the secondary part and is curved. 4. The ball joint according to claim 1, wherein the ball joint is molded in a state. A plurality of slits in the meridian direction are provided at the bottom of the primary part, and circumferential grooves are provided in the inner periphery and the outer periphery of the primary part in response to the spring reaction force of the elastic deformation of the secondary part. 5. The ball joint according to claim 1, wherein the bottom part of the primary part presses a lower part of the spherical part of the secondary part.