JP4516079B2 - Ball joint - Google Patents

Description

The present invention relates to a ball join preparative used for moving parts such as various machine.

  The ball joint includes a housing, a ball stud having a ball portion, a ball seat accommodated in the housing, a dust cover, and the like. A concave spherical surface into which the ball portion is rotatably fitted is formed inside the ball seat. The ball seat is formed with an overhang portion to prevent the ball portion from coming off the concave spherical surface. The inner diameter of the overhang portion is smaller than the outer diameter of the ball portion. For this reason, when the ball portion is inserted into the concave spherical surface, an axial load is applied to the ball stud, and the ball portion is inserted into the concave spherical surface while forcibly spreading the overhang portion by the ball portion.

  As a means for fixing the ball seat to the housing, a projection is formed at the bottom of the ball seat made of thermoplastic resin, a hole is formed at the bottom of the housing, the projection is inserted into this hole, and a heat is applied to the tip of the projection. It has been proposed to fix the ball seat to the housing by applying deformation (heat caulking) (for example, Japanese Patent No. 3168229).

  Further, as another means for fixing the ball seat to the housing, a method has been proposed in which a caulking portion is provided in the opening of the housing and the end surface of the ball seat is pressed by bending the caulking portion inward (for example, Japanese Utility Model Publication No. 61-116227).

  As in Japanese Patent No. 3168229, when a protrusion provided on a part of a ball seat is protruded from a hole at the bottom of the housing and fixed by heat caulking, for example, when an obstacle such as stepping stone hits the bottom of the housing, When corrosive liquid such as strong acid is applied, the projection made of synthetic resin is damaged, and there is a concern that the fixation of the ball seat is loosened. Further, since the protrusion protrudes from the bottom of the housing, there are problems that the axial dimension of the housing is large and it is difficult to fix a rod member (tie rod or the like) to the bottom of the housing.

  In the case of plastic processing (caulking) the housing opening as disclosed in Japanese Utility Model Publication No. 61-116227, when an axial pulling load is applied to the ball stud, the ball portion deforms the overhang portion ( (Destroy). In addition, the caulking load when a part of the housing is caulked directly acts on the end surface of the ball seat, so that stress is generated in the ball seat, the frictional force between the ball seat and the ball portion becomes unstable, and the operating torque Causes problems such as instability.

Accordingly, an object of the present invention, it is possible to reliably fix the ball seat to the housing, yet to provide a high ball join preparative strength against pull-out load of the ball stud.

  The ball joint of the present invention includes a metal housing having an opening, a ball stud having a shaft portion and a ball portion, a synthetic resin ball seat accommodated in the housing, and the ball inside the opening. It has a stopper ring and a caulking portion that are arranged on the end face of the sheet.

  The ball seat includes a concave spherical surface into which the ball portion is inserted, an overhang portion having an inner diameter smaller than the outer diameter of the ball portion so as to prevent the ball portion from coming out of the concave spherical surface, and the shaft portion. And an inclined surface having a shape in which an inner diameter expands from the overhang portion toward the opening.

  The stopper ring has a ring-shaped base portion and a stopper portion that is formed on the inner peripheral side of the base portion and extends toward the overhang portion and faces the slope portion. The caulking portion fixes the stopper ring to the housing by bending a protruding edge formed on the end wall of the opening of the housing toward the stopper ring.

The thickness of the flange which constitutes the clamping portion or is 10% to 40% of the wall thickness of the end wall of the front Symbol opening.

FIG. 1 is a cross-sectional view of a ball joint according to a first embodiment of the present invention. FIG. 2 is a plan view of a stopper ring used in the ball joint shown in FIG. FIG. 3 is an enlarged cross-sectional view showing a caulking portion of the ball joint shown in FIG. FIG. 4 is a diagram illustrating the relationship between the thickness ratio of the caulking portion, the caulking load, and the breaking load. FIG. 5 is a perspective view showing a stopper ring according to the second embodiment of the present invention. FIG. 6 is a perspective view showing a part of a ball seat according to the second embodiment of the present invention. FIG. 7 is a perspective view of the stopper ring shown in FIG. 5 overlaid on the ball seat shown in FIG. FIG. 8 is a plan view showing a stopper ring according to a third embodiment of the present invention. FIG. 9 is a plan view showing a stopper ring according to a fourth embodiment of the present invention. FIG. 10 is a bottom view showing a ball seat according to the fifth embodiment of the present invention. FIG. 11 is a cross-sectional view showing the caulking portion of the sixth embodiment of the present invention. FIG. 12 is a cross-sectional view showing the caulking portion of the seventh embodiment of the present invention. FIG. 13: is sectional drawing which shows the ball joint of the 8th Embodiment of this invention. FIG. 14 is a cross-sectional view showing the caulking portion of the ninth embodiment of the present invention. FIG. 15 is a cross-sectional view showing a ball joint according to a tenth embodiment of the present invention. FIG. 16: is sectional drawing which shows the ball joint of the 11th Embodiment of this invention.

  A first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 shows a ball joint 10 of this embodiment. Although the use of the ball joint 10 is not limited, as an example, the ball joint 10 is used for a stabilizer link that connects a stabilizer constituting a suspension mechanism of an automobile and a vehicle body.

  The ball joint 10 includes a housing 11, a ball stud 12, a ball seat 13, a stopper ring 14, a dust cover 15, and the like. A rod member 16 is welded to the housing 11.

  The housing 11 is made of, for example, a metal such as carbon steel, and has an opening 20 located on the upper side in FIG. 1, a cylindrical peripheral wall 21, a bottom 22 located on the opposite side of the opening 20, and the like. On the end wall 20 a of the opening 20, a protruding edge 25 constituting a caulking portion 80 described later is formed. A dust cover mounting groove 26 is formed in the vicinity of the opening 20 on the outer surface of the peripheral wall 21. The dust cover mounting groove 26 is continuous in the circumferential direction of the peripheral wall portion 21.

  The ball stud 12 is made of metal and has a shaft portion 30 and a ball portion 31. The shaft portion 30 and the ball portion 31 are formed integrally with each other. The shaft portion 30 is formed with a male thread portion 35, a first flange portion 36, a second flange portion 37, a small diameter portion 38, and the like. The diameter of the first flange 36 is larger than the diameter of the second flange 37. A dust cover mounting portion 39 is formed between the flange portions 36 and 37. The dust cover mounting portion 39 is continuous in the circumferential direction of the ball stud 12. The tip surface 31a of the ball part 31 is formed into a flat shape.

  The ball seat 13 is made of synthetic resin and is accommodated in the housing 11. The ball seat 13 includes a concave spherical surface 50 into which the ball portion 31 is inserted, an overhang portion 51 that prevents the ball portion 31 from being removed, and an insertion of the ball portion 31 when the ball portion 31 is inserted into the concave spherical surface 50. , A side wall portion 53 formed around the concave spherical surface 50, a bottom wall portion 54, and the like. The overhang part 51, the side wall part 53, and the bottom wall part 54 are integrally formed with each other.

  The ball portion 31 and the concave spherical surface 50 are fitted so as to be rotatable around the axis X of the ball seat 13. Moreover, the ball portion 31 is fitted to the concave spherical surface 50 so that the ball stud 12 can be tilted with respect to the axis X of the ball seat 13 and the head can be swung in all directions. ing.

  An inner diameter D1 (shown in FIG. 1) of the overhang portion 51 is smaller than an outer diameter D2 of the ball portion 31. The overhang portion 51 prevents the ball portion 31 inserted into the concave spherical surface 50 from coming out of the concave spherical surface 50.

  The slope 52 is formed on the inner peripheral surface of the hole 60 (shown in FIG. 1) of the ball seat 13 through which the shaft 30 of the ball stud 12 is inserted. The slope portion 52 has a tapered shape in which the inner diameter increases from the overhang portion 51 toward the opening portion 20 of the housing 11. The slope portion 52 is continuous with the end surface 13 a of the ball seat 13.

  The bottom portion 22 of the housing 11 and the bottom wall portion 54 of the ball seat 13 have a shape forming a part of a sphere along the outer peripheral surface of the ball portion 31. The bottom wall portion 54 of the ball seat 13 overlaps the bottom portion 22 of the housing 11. Between the bottom wall portion 54 of the ball seat 13 and the tip surface 31 a of the ball portion 31, a space portion 61 that can store a lubricant such as grease is formed.

  The stopper ring 14 is disposed inside the opening 20 of the housing 11 so as to overlap the end surface 13 a of the ball seat 13. As shown in FIG. 2, the stopper ring 14 includes a ring-shaped base portion 70 and a stopper portion 71 formed integrally with the base portion 70 on the inner peripheral side of the base portion 70.

  The stopper portion 71 extends toward the overhang portion 51 along the slope portion 52 so as to face the slope portion 52 of the ball seat 13. The inner diameter D3 (shown in FIGS. 1 and 2) of the stopper ring 14 is set to a size that does not interfere with the locus drawn by the ball portion 31 when the ball stud 12 swings. A symbol Z in FIG. 3 indicates a locus when the ball portion 31 rotates.

  An example of the material of the stopper ring 14 is metal. However, in addition to the metal, a resin having higher strength than the material of the ball sheet 13 may be used, or a fiber reinforced synthetic resin may be used.

  A caulking portion 80 is provided in the opening 20 of the housing 11. The caulking portion 80 is configured by plastically deforming the protruding edge 25 formed integrally with the end wall 20 a of the opening 20 of the housing 11. A thickness t (shown in FIG. 3) of the projecting edge 25 is not more than half of a thickness T of the end wall 20 a of the opening 20. The caulking portion 80 is desirably provided over the entire circumference of the housing 11, but may be provided in a part of the circumferential direction of the housing 11 if there is no problem in strength.

  In order to form the caulking portion 80, as shown in FIG. 3, first, a load P1 along the radial direction of the ball seat 13 is applied to the protruding edge 25 in the first caulking step. Due to this radial load P1, the protruding edge 25 is plastically deformed so as to be inclined approximately 45 ° inwardly as indicated by a two-dot chain line L1.

  Next, in the second caulking step, a load P <b> 2 along the axis X direction of the ball seat 13 is applied to the protruding edge 25. Due to the load P2, the protruding edge 25 is plastically deformed so that the base 70 of the stopper ring 14 is sandwiched between the protruding edge 25 and the end surface 13a of the ball seat 13. Since the root of the caulking portion 80 is curved with a radius of curvature R, it is possible to reduce the caulking portion 80 from excessively pressing the ball seat 13.

  In this manner, first, the caulking portion 80 is formed by applying the axial load P2 in the second step after the projecting edge 25 is inclined and deformed to about 45 ° by the radial load P1 in the first step. Therefore, it is possible to avoid that the caulking load is excessively applied to the ball sheet 13.

  As shown in FIG. 3, the width W <b> 1 of the caulking portion 80 is 50% or more of the width W <b> 2 of the end surface 13 a of the ball sheet 13. By doing so, a stable caulking portion 80 can be obtained, and the caulking portion 80 can exhibit a stable pulling strength against the pulling load of the ball stud 12 (the pulling load applied in the direction of the axis X).

  In addition, as shown in FIG. 1, the caulking portion 80 includes a portion where the distance from the outer peripheral surface 13 b of the ball seat 13 to the concave spherical surface 50 is extended in the axis X direction of the ball seat 13, and the ball seat 13. Is formed in a region S between the outer peripheral surface 13b of the first and second outer surfaces. In this region S, since the thickness of the ball sheet 13 is secured in the axis X direction, the ball sheet 13 can sufficiently withstand the caulking load even if the ball sheet 13 is loaded with the caulking load in the axis X direction. it can.

  A solid line m1 shown in FIG. 4 indicates a relationship between a load (referred to as a caulking load) necessary for plastic deformation of the protruding edge 25 by the caulking and a thickness ratio (t / T). A broken line m2 shown in FIG. 4 shows a relationship between a load (called a breaking load) at which the caulking portion 80 breaks when a drawing load in the direction of the axis X is applied to the caulking portion 80 and the thickness ratio (t / T). ing. The lower limit A of the wall thickness ratio that satisfies the target value of the breaking load was 0.1.

  When the wall thickness ratio (t / T) increases, the fracture load also increases. However, when the wall thickness ratio (t / T) exceeds a certain value B, the caulking load increases rapidly, and processing becomes difficult. The value B at which the caulking load increases rapidly was 0.4. For the above reasons, the wall thickness t of the projecting edge 25 is preferably 10% to 40% of the wall thickness T of the end wall 20a of the opening 20. By setting the wall thickness ratio within this range, it is possible to balance the punching strength of the ball stud 12 and the load necessary for caulking. Moreover, it can avoid that the opening part 20 vicinity receives the influence of a deformation | transformation by the caulking load of the protrusion 25. FIG.

  As shown in FIG. 1, one end 15a of the rubber dust cover 15 is fitted into the dust cover mounting groove 26 of the housing 11 and fixed to the housing 11 by a retaining ring 90 such as a circlip. The other end 15 b of the dust cover 15 is fitted into the dust cover mounting portion 39 of the ball stud 12.

  As indicated by a two-dot chain line L2 in FIG. 1, when the ball stud 12 is inclined by a predetermined amount with respect to the axis X of the ball seat 13, the shaft portion 30 of the ball stud 12 abuts against the stopper portion 71 of the stopper ring 14. The ball stud 12 is prevented from further tilting.

The ball joint 10 is manufactured through the processes described below.
(1) The stopper ring 14 having the ring-shaped base portion 70 and the stopper portion 71 is formed by press working or the like.

(2) The ball portion 31 of the ball stud 12 is inserted into the concave spherical surface 50 of the ball seat 13. During this step, the stopper ring 14 may be overlaid on the end surface 13 a of the ball sheet 13.

(3) The ball seat 13 with the ball part 31 inserted is inserted into the housing 11.

(4) The stopper ring 14 is overlaid at a predetermined position on the end surface 13 a of the ball seat 13.

(5) By applying a radial load P <b> 1 (shown in FIG. 3) toward the shaft portion 30 to the protruding edge 25 of the housing 11, the protruding edge 25 is plastically deformed so as to be inclined inward. This step is the first caulking step.

(6) By applying a load P2 along the axis X direction of the ball seat 13 to the protruding edge 25, the base portion 70 of the stopper ring 14 is sandwiched between the protruding edge 25 and the end surface 13a of the ball sheet 13. The protruding edge 25 is plastically deformed. This step is the second caulking step.

  According to the ball joint 10 of the present embodiment, the ball portion 31 is prevented from coming off by the overhang portion 51 when a pulling load in the axis X direction is applied to the ball stud 12. When an excessive load that deforms the overhang portion 51 acts in the direction of the axis X, the deformation of the overhang portion 51 can be suppressed by the stopper portion 71. Since the stopper ring 14 is securely fixed to the housing 11 by the caulking portion 80, the ball joint 10 can exhibit a high punching strength.

  The ball seat 13 according to the present embodiment is fixed to the housing 11 via the stopper ring 14 by caulking a protruding edge 25 formed on the metal housing 11. For this reason, the punching strength can be increased as compared with the conventional case in which the ball seat is fixed to the housing by heat caulking.

  Further, since a part of the ball seat 13 made of synthetic resin does not protrude from the bottom portion 22 of the housing 11, it is not easily affected by stepping stones or corrosive liquid. Moreover, the rod member 16 can be welded to the bottom 22 of the housing 11 at an arbitrary angle. Moreover, it is not necessary to make the bottom part 22 of the housing 11 and the bottom wall part 54 of the ball seat 13 flat. Therefore, the bottom portion 22 of the housing 11 and the bottom wall portion 54 of the ball seat 13 can be formed into a shape that forms a part of a sphere according to the outer peripheral shape of the ball portion 31, and the housing 11 can be reduced in size. it can.

  In the ball joint 10 of this embodiment, since the stopper ring 14 is interposed between the ball sheet 13 and the caulking portion 80, it is possible to avoid the caulking load from being directly applied to the ball sheet 13. It is possible not to reach the limit.

  5 to 7 show a stopper ring 14A and a part of a ball seat 13A according to the second embodiment of the present invention. As shown in FIG. 5, a plurality of slits 100 are formed in the stopper portion 71 of the stopper ring 14A at intervals in the circumferential direction of the stopper ring 14A. As shown in FIG. 6, the ball sheet 13 </ b> A has a convex portion 101 that is inserted into the slit 100.

  As shown in FIG. 7, in a state where the stopper ring 14A is overlaid on the ball sheet 13A, the convex portion 101 protrudes from the slit 100 toward the shaft portion 30 of the ball stud 12 (shown in FIG. 1). Yes. For this reason, when the ball stud 12 is tilted by a predetermined amount with respect to the ball seat 13 </ b> A, the shaft portion 30 of the ball stud 12 contacts the convex portion 101.

  According to this embodiment, when the ball stud 12 is inclined, the shaft portion 30 of the ball stud 12 can come into contact with the convex portion 101 made of synthetic resin. For this reason, it is possible to avoid the metal ball stud 12 and the stopper ring 14 </ b> A from being directly (contact between metals).

  FIG. 8 shows a stopper ring 14B according to a third embodiment of the present invention. The stopper ring 14B is composed of a first ring piece 110 and a second ring piece 111 which are divided into two in the radial direction. By combining the ring pieces 110 and 111, the stopper ring 14B is configured. Yes.

  According to such a split type stopper ring 14B, even if the inner diameter D3 of the stopper ring 14B is smaller than the outer diameters of the ball portion 31 and the flange portion 36 of the ball stud 12 (shown in FIG. 1), the stopper ring 14B is pivoted. The unit 30 can be disposed at a predetermined position.

  FIG. 9 shows a stopper ring 14C according to a fourth embodiment of the present invention. The stopper ring 14C is formed with a cut 120 in a part in the circumferential direction. The stopper ring 14C has a C shape when viewed from the plane direction.

  In the case of the C-shaped stopper ring 14C having such a cut 120, even if the inner diameter D4 of the stopper ring 14C is smaller than the outer diameter of the ball portion 31 or the flange portion 36 of the ball stud 12 (shown in FIG. 1), the stopper By passing the small diameter portion 38 of the ball stud 12 from the direction of arrow E through the cut 120 of the ring 14C, the stopper ring 14C can be disposed at a predetermined position of the shaft portion 30.

  FIG. 10 shows the bottom surface of a ball seat 13B according to the fifth embodiment of the present invention. The ball sheet 13 </ b> B has a plurality of grooves 130 formed on the concave spherical surface 50. When a lubricant such as grease enters the groove portion 130, the friction surface between the ball sheet 13B and the ball portion 31 (shown in FIG. 1) is effectively lubricated.

  Further, in this ball sheet 13B, a through hole 131 is formed in the bottom wall portion 54 so that the air on the tip side of the ball portion 31 can be extracted when the ball portion 31 is inserted into the concave spherical surface 50. The through hole 131 communicates with the groove 130. By forming such a through hole 131, it is possible to prevent air from being trapped between the ball portion 31 and the bottom wall portion 54 when the ball portion 31 is inserted into the concave spherical surface 50. It is possible to prevent the bottom wall portion 54 from being damaged by the pressure.

  FIG. 11 shows a part of the ball seat 13 and the caulking portion 80 of the housing 11 according to the sixth embodiment of the present invention. The caulking portion 80 of the housing 11 has a protruding edge 25 formed so that a cross section along the axial direction is arcuate. By forming the protrusion 25 in an arc shape in this way, it is possible to reduce the springback that occurs when the protrusion 25 is caulked (the protrusion 25 returns in the direction indicated by the two-dot chain line F in FIG. 3). .

  FIG. 12 shows a part of the ball seat 13 and the stopper ring 140 according to the seventh embodiment of the present invention. The stopper ring 140 has a substantially flat shape, but the stopper portion 141 extends toward the overhang portion 51, and a part of the stopper ring 140 faces the slope portion 52 of the stopper ring 140. The stopper ring 140 having a flat shape can be employed in the case of a ball joint in which the ball portion 31 may have a relatively small pull-out strength.

  FIG. 13 shows a ball joint 10 according to an eighth embodiment of the present invention. In this embodiment, the rod member 16 is fixed to the bottom 22 of the housing 11 by welding or the like. The attachment angle of the rod member 16 is arbitrary. For example, the rod member 16 may be fixed to the bottom 22 of the housing 11 so that the rod member 16 is positioned straight on the axis X of the ball seat 13 as indicated by a two-dot chain line L3 in FIG. A hole 145 that can be used as a grease reservoir is formed in the bottom wall portion 54 of the ball seat 13.

  FIG. 14 shows a part of the ball seat 13 and a part of the stopper ring 14 according to the ninth embodiment of the present invention. In this embodiment, a stepped portion 150 is formed on the inner peripheral surface of the end portion of the housing 11, and the outer end 70 a of the base portion 70 of the stopper ring 14 is supported by the stepped portion 150. According to this embodiment, when the projecting edge 25 constituting the caulking portion 80 is caulked, the caulking load applied to the projecting edge 25 is supported by the step portion 150 via the base portion 70 of the stopper ring 14. It is possible to suppress the load from being input to the ball seat 13.

  FIG. 15 shows a ball joint 10 according to a tenth embodiment of the present invention. A ring-shaped reinforcing material 160 is provided inside one end 15a of the dust cover 15 of this embodiment. The housing 11 is attached to the one end 15 a of the dust cover 15 by press-fitting the one end 15 a of the dust cover 15 into the peripheral wall portion 21 of the housing 11. Since the other configuration is the same as that of the ball joint 10 of the first embodiment (FIG. 1), the same reference numerals are assigned to the same portions as those of the first embodiment, and the description thereof is omitted.

  FIG. 16 shows a ball joint 10 according to an eleventh embodiment of the present invention. In the stopper part 71 of this embodiment, it formed by press molding etc. so that the plate | board thickness may become thin toward the front end side. Since the other configuration is the same as that of the ball joint 10 of the first embodiment (FIG. 1), the same reference numerals are assigned to the same portions as those of the first embodiment, and the description thereof is omitted. If comprised in this way, it can prevent that the edge of the front end side of the stopper part 71 and the ball stud 12 interfere, and can take the rocking | fluctuation angle of the ball stud 12 larger.

  According to the present invention, the ball seat can be securely fixed to the housing by the caulking portion obtained by caulking the protruding edge formed in the opening portion of the housing and the stopper ring provided inside the opening portion. In addition, it is possible to exert a large pulling strength against the drawing load applied in the axial direction of the ball stud. In addition, part of the ball seat does not protrude from the bottom of the housing.

Claims (1)

A metal housing having an opening;
A ball stud having a shaft portion and a ball portion;
A ball seat made of synthetic resin accommodated in the housing, the concave spherical surface into which the ball portion is inserted, and smaller than the outer diameter of the ball portion to prevent the ball portion from coming out of the concave spherical surface. A ball sheet having an overhang portion having an inner diameter, and a slope portion formed in a hole portion through which the shaft portion is inserted, and having an inner diameter expanding from the overhang portion toward the opening,
A stopper ring that is disposed on the inner surface of the ball seat inside the opening, and is formed on a ring-shaped base portion and an inner peripheral side of the base portion, and extends toward the overhang portion to the slope portion. A stopper ring having an opposing stopper portion;
A caulking portion that fixes the stopper ring to the housing by bending a protruding edge formed on the end wall of the opening of the housing toward the stopper ring ;
The ball joint characterized in that the thickness of the protruding edge constituting the caulking portion is 10% to 40% of the thickness of the end wall of the opening .

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