JP5359435B2 - Ball joint fastening structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fastening structure of a ball joint which can restrain the ball joint from rattling even if an excessive impact force than expected is applied. <P>SOLUTION: In structure which fastens a lower arm on a lower arm portion 3 of a knuckle steering by the ball joint 6 and a fastening bolt 14, the ball joint 6 is composed of a cylinder portion 7 which includes convex portions 13 on a surface inserted from one surface 3a of the lower arm portion 3 into an aperture 5, a female threaded portion 8 formed on an inside surface of the cylinder portion 7, a collar portion 9 provided on a base end side of the cylinder portion 7 and a sphere portion 10 provided on the collar portion 9. The fastening bolt 14 is configured to include an enlarged diameter portion 16 which is inserted from the other surface 3b of the lower arm portion 3 into the aperture 5 and then allows the convex portions 13 to grip on the inside surface 5a of the aperture 5 by making diameter of the cylinder portion 7 enlarge, a male threaded portion 15 which is fastened by threadably engaging with the female threaded portion 8 inside the cylinder portion 7, and a head portion 17. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a fastening structure for a ball joint.

  For example, a suspension member mounting structure has been proposed in which an upper arm or a lower arm constituting a suspension is attached to an upper arm or a lower arm of a knuckle steering, which is an automobile axle part, using a ball joint (for example, Patent Document 1). Description).

  In the mounting structure described in Patent Document 1, a constriction is formed on the outer periphery of the shaft portion of the ball stud protruding from the ball joint support member when the ball joint and the lower arm are connected, while the stud mounting hole is formed in the fastening portion of the lower arm. And a slit groove is formed so that the fastening portion has a bifurcated shape, and a bolt hole is formed through the bifurcated fastening portion so as to cross the slit groove. In this mounting structure, the ball stud shaft portion is inserted into the stud shaft mounting hole of the bifurcated fastening portion, and the fastening bolt is inserted into the bolt hole of the bifurcated fastening portion so that the outer periphery thereof is in contact with the constricted portion of the ball stud shaft portion. The structure is inserted and tightened.

Japanese Utility Model Publication No. 61-36805

  The mounting structure described in Patent Document 1 is a structure in which a ball joint and a lower arm are fastened by a so-called slit fastening structure in which a stud shaft mounting hole for inserting a ball stud is a straight hole and a fastening portion is bifurcated. . For this reason, in this mounting structure, if an excessive impact force is applied than expected, the ball stud constriction part or the tightening bolt in contact with the ball stud constriction part will be crushed and the ball joint shaft fastening part will be rattled. It can happen.

  Also, with this mounting structure, there are many processing parts (stud shaft mounting holes, bolt holes, slit grooves, etc.) in the fastening part of the lower arm, and multiple types of tools must be used for each part, resulting in high processing costs. Become.

  Therefore, an object of the present invention is to provide a ball joint fastening structure capable of suppressing the rattling of the ball joint when an excessive impact force is applied.

The ball joint fastening structure according to the present invention is formed in the cylindrical portion of the ball joint by inserting the ball joint into the hole from one surface of the attachment and inserting the bolt into the hole from the other surface. By screwing the bolt part into the female thread part, the ball joint is fastened to the object to be attached. Then, the plurality of convex portions formed on the surface of the cylindrical portion have a structure in which the diameter of the cylindrical portion is increased by an enlarged diameter portion that is inserted into the hole portion, and is pressed against the inner surface of the hole portion. At that time, in a state where the entire cylindrical portion between the flange portion of the ball joint and the head portion of the bolt portion is located in the hole portion of the attachment object, the cylindrical portion is expanded by the enlarged diameter portion. The convex portion is pressed against the inner surface of the hole, and the attached object is inserted into the female screw portion and the head from the one surface side and the other surface side at the flange portion of the ball joint and the head portion of the bolt portion. The object to be attached is clamped by being tightened by fastening the bolt part.

  According to the ball joint fastening structure of the present invention, when the fastening bolt is fastened to the ball joint, the diameter of the cylindrical portion of the ball joint is enlarged by the enlarged diameter portion, and the plurality of convex portions formed on the surface of the cylindrical portion are provided. Since the inner surface of the hole to be attached is pressed against the inner surface of the hole, the ball joint can be firmly fixed to the object to be attached by pressing (biting) the inner surface of the hole. That is, the fastening structure of the present invention has an expansion function for expanding the diameter of the cylindrical portion, so that it is possible to suppress the rattling of the ball joint. As a result, according to the present invention, it is possible to suppress the rattling of the ball joint even when an excessive impact force more than expected is applied.

In addition, according to the fastening structure of the ball joint of the present invention, since it is not a fastening structure with bolts and nuts as in the conventional structure, it is possible to reduce the processing parts such as troublesome slot grooving that requires processing man-hours. Since it is sufficient to process only the hole portion, it can be easily processed and the cost of parts can be reduced.
Further, according to the ball joint fastening structure of the present invention, the diameter-enlarged portion has a shape in which the diameter gradually increases from the distal end side, which is the insertion direction into the cylindrical portion, toward the proximal end side. The cylindrical portion can be firmly pressed against the inner surface of the hole as the diameter-expanded portion enters deeper.
Further, according to the fastening structure of the ball joint of the present invention, it is fastened by fastening the female screw part and the bolt part from one side and the other side of the attachment object at the collar part and the head part of the bolt part. Since the object to be attached is held, loosening of the ball joint in the axial direction can be prevented.

FIG. 1 is a perspective view showing an example in which the ball joint fastening structure of Embodiment 1 is applied to a knuckle steering. 2A is a partially broken view showing a state before the ball joint is attached to the knuckle steering hole of FIG. 1 and fastened with a fastening bolt, and FIG. 2B is a view showing fastening of the fastening bolt to the ball joint. It is a figure which shows the state made to partly fracture | rupture. 3 (A) is a front view of the ball joint of FIG. 1, FIG. 3 (B) is a diagram showing a part of the ball joint broken, and FIG. 3 (C) is a part of the cylindrical part of the ball joint. It is a principal part expansion perspective view expanded and shown. FIG. 4 is a perspective view showing an example in which the ball joint fastening structure of the second embodiment is applied to knuckle steering. 5A is a partially broken view showing a state before the ball joint is attached to the knuckle steering hole of FIG. 4 and fastened with a fastening bolt, and FIG. 5B is a view showing fastening of the fastening bolt to the ball joint. It is a figure which shows the state made to partly fracture | rupture.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

“Embodiment 1”
FIG. 1 is a perspective view showing an example in which the ball joint fastening structure of Embodiment 1 is applied to a knuckle steering, and FIG. 2 (A) is a view before attaching a ball joint to the hole of the knuckle steering of FIG. FIG. 2B is a partially broken view showing a state in which a fastening bolt is fastened to the ball joint, and FIG. 3A is a front view of the ball joint in FIG. FIG. 3B is a view showing a part of the ball joint in a cutaway manner, and FIG. 3C is an enlarged perspective view of a main part showing an enlarged part of the cylindrical part of the ball joint.

  In the first embodiment, the ball joint fastening structure according to the present invention is applied to a knuckle steering 1 (corresponding to a mounted object of the present invention) which is an axle part for an automobile. In the first embodiment, of the upper arm 2, the lower arm 3, or the knuckle arm 4 provided in the knuckle steering 1, a lower arm constituting a suspension is attached to the lower arm 3.

  The lower arm 3 is formed with a hole 5 for fixing a ball joint for attaching the lower arm to the knuckle steering 1 with a fastening bolt. The hole 5 is formed as a straight circular hole penetrating from one surface 3a of the lower arm 3 to the other surface 3b. The hole 5 can be formed, for example, by a reamer process that provides a hole diameter accuracy after drilling, which is a general processing method.

  The ball joint 6 includes a cylindrical portion 7 inserted into the hole portion 5, a female screw portion 8 formed on the inner surface 7 a of the cylindrical portion 7, a collar portion 9 provided on the proximal end side of the cylindrical portion 7, And a spherical portion 10 provided on the collar portion 9.

  The cylindrical portion 7 is inserted and fitted into the hole portion 5 and has a length that does not protrude from the hole portion 5. The cylindrical portion 7 is formed with a slit 11 that is an elongated cutout groove from the distal end side toward the proximal end side. A plurality of slits 11 are formed at predetermined intervals in the circumferential direction of the cylindrical portion 7, and the cylindrical portion 7 is formed as several tongue pieces 12 having a cantilever shape. Each of the tongue pieces 12 is pushed outward and displaced by inserting a later-described enlarged diameter portion into the cylindrical portion 7.

  A plurality of convex portions 13 are formed on the surface of the cylindrical portion 7. The convex portion 13 is formed from the distal end side to the proximal end side of the cylindrical portion 7 with the cross-sectional shape having a sharpened tip as a protrusion having an inverted V shape. Specifically, a plurality of convex portions 13 are formed on the surface of each tongue piece 12 as ridges having an inverted V shape from the distal end side toward the proximal end side. From another viewpoint, the surface of the cylindrical portion 7 is like a knurl having a plurality of convex portions 13 formed on the peripheral surface.

  The inner surface 7a of the cylindrical portion 7 has an inclined surface that forms a conical shape so that its inner diameter gradually decreases from large to small as it goes from the tip 7b side to the back side where the female screw portion 8 is formed. Has been.

  The female screw portion 8 is formed in a portion at the back from the entrance of the cylindrical portion 7. A male screw portion of a fastening bolt is screwed into the female screw portion 8.

  The collar portion 9 is integrated with the base end of the cylindrical portion 7 as a disk shape. The collar portion 9 is in contact with one surface 3 a of the lower arm portion 3 so as to be in close contact with each other, and functions as a retaining for the cylindrical portion 7 with respect to the hole portion 5.

  The spherical body portion 10 is integrally provided on the flange portion 9 on the opposite side to the cylindrical portion 7. The spherical body portion 10 is connected to a spherical body receiving portion (not shown) attached to the lower arm.

  A fastening bolt 14, which is a bolt part for fastening the ball joint 6 to the lower arm part 3, has a male screw part 15, an enlarged diameter part 16 for enlarging the diameter of the cylindrical part 7, and a head part 17. .

  The male screw portion 15 is formed on the distal end side of the fastening bolt 14 and is screwed into the female screw portion 8. The enlarged diameter portion 16 is formed integrally with the fastening bolt 14 between the male screw portion 15 and the head portion 17, and extends from the distal end side to the proximal end side in the insertion direction into the cylindrical portion 7 ( From another viewpoint, the taper shape gradually increases in diameter (from the male screw portion 15 side toward the head portion 17 side). The diameter of the tapered enlarged diameter portion 16 is larger than the inner diameter of the cylindrical portion 7 at the proximal end portion. The head portion 17 is provided on the proximal end side where the diameter of the enlarged diameter portion 16 is increased. The head 17 is a screw head that comes into close contact with the other surface 3 b of the lower arm 3.

  In order to fix the ball joint 6 to the lower arm portion 3 of the knuckle steering 1, after inserting the cylindrical portion 7 of the ball joint 6 into the hole 5 of the lower arm portion 3 from one surface 3a, the other side on the opposite side is inserted. The fastening bolt 14 is attached from the surface 3b. When the male screw portion 15 and the enlarged diameter portion 16 of the fastening bolt 14 are inserted into the cylindrical portion 7, the male screw portion 15 is screwed into the female screw portion 8 in the cylindrical portion 7, and the fastening bolt 14 is screwed into the inside of the cylindrical portion. Go.

  At this time, since the enlarged diameter portion 16 enters deep inside the cylindrical portion 7, the tongue pieces 12 constituting the cylindrical portion 7 are pushed outward by being pushed by the enlarged diameter portion 16. That is, the cylindrical portion 7 increases its diameter by entering the enlarged diameter portion 16, and causes the convex portion 13 formed on the surface to bite the inner surface 5 a of the hole portion 5. Then, by tightening the fastening bolt 14, the lower arm portion 3 is sandwiched between the flange portion 9 of the ball joint 6 and the head portion 17 of the fastening bolt 14. Therefore, the ball joint 6 is difficult to rotate due to the vibrations from the knuckle steering 1 and the lower arm due to the plurality of ridges 13 forming the knurling formed on the surface of the cylindrical portion 7 biting in. As a result, the ball joint 6 is positioned in the rotational direction. Moreover, since the lower arm part 3 is clamped by the collar part 9 and the head part 17 by fastening the fastening bolt 14, the ball joint 6 is positioned in the axial direction.

According to the ball joint fastening structure configured as described above, when the fastening bolt 14 is fastened to the ball joint 6, the diameter of the cylindrical portion 7 of the ball joint 6 is expanded outwardly by the enlarged diameter portion 16. , since the bite a plurality of convex portions 13 formed on the surface of the cylindrical portion 7 to the inner surface 5a of the hole 5 of the lower arm 3, by pressing (bite) for the hole inner surface 5a of the convex portion 13, The ball joint 6 can be firmly fixed to the lower arm portion 3. Therefore, according to the present invention, rattling of the ball joint 6 can be suppressed even when an excessive impact force more than expected is applied.

  Further, according to the fastening structure of the ball joint of the present invention, since it is not a fastening structure with bolts and nuts as in the conventional structure, it is possible to reduce a processing part such as troublesome slot groove processing which requires a processing man-hour. Therefore, the hole 5 can be easily processed, and the parts cost of the knuckle steering 1 can be reduced.

  Further, according to the fastening structure of the ball joint of the present invention, the slit 11 is formed in the cylindrical portion 7 of the ball joint 6 from the distal end side toward the proximal end side, and the slit 11 is formed around the circumference of the cylindrical portion 7. Since a plurality of them are formed in the direction, it becomes easy to expand the diameter of the cylindrical portion 7 so as to push and widen the expanded diameter portion 16 inserted into the cylindrical portion when the fastening bolt 14 is fastened.

  Further, according to the fastening structure of the ball joint of the present invention, the convex portion 13 formed on the surface of the cylindrical portion 7 is formed as a protrusion with a sharpened tip from the distal end side to the proximal end side of the cylindrical portion 7. Therefore, the pointed portion easily bites into the inner surface 5a of the hole 5, and the ball joint 6 can be prevented from loosening with respect to the hole 5.

  Further, according to the fastening structure of the ball joint of the present invention, the enlarged diameter portion 16 has a tapered shape that gradually increases in diameter from the distal end side to the proximal end side, which is the insertion direction into the cylindrical portion 7. The cylindrical portion 7 can be firmly pressed against the inner surface 5 a of the hole portion 5 as the diameter-enlarged portion 16 enters the inner portion of the cylindrical portion 7.

  Further, according to the fastening structure of the ball joint of the present invention, since the enlarged diameter portion 16 is formed integrally with the fastening bolt 14, the number of parts can be reduced and the part cost can be reduced. It becomes.

  Further, according to the fastening structure of the ball joint of the present invention, the female screw portion 8 is connected to the flange portion 9 of the ball joint 6 and the head portion 17 of the fastening bolt 14 from the one surface 3a side and the other surface 3b side of the lower arm portion 3. Since the lower arm portion 3 is clamped by fastening the male screw portion 15, loosening of the ball joint 6 in the axial direction can be prevented.

“Embodiment 2”
4 is a perspective view showing an example in which the ball joint fastening structure of the second embodiment is applied to a knuckle steering. FIG. 5A is a view before attaching the ball joint to the hole of the knuckle steering and fastening with a fastening bolt. FIG. 5B is a partially broken view showing a state where the fastening bolt is fastened to the ball joint.

  In the second embodiment, the enlarged diameter portion 16 of the first embodiment is formed as a separate component from the fastening bolt 14, and the enlarged diameter component 18 that is the enlarged diameter portion is mounted on the fastening bolt 14. The diameter-expanded part 18 formed as a separate part is formed as a truncated cone having a substantially trapezoidal cross section with a diameter gradually increasing from one end side to the other end side. The diameter-expanded component 18 is formed by inserting the bolt main body portion 20 of the fastening bolt 14 through a through hole 19 formed in the center portion and bringing the base end surface 18a having the maximum diameter into contact with the head portion 17 so that the fastening bolt 14 Attached to. Unlike the first embodiment, the fastening bolt 14 that is the bolt portion of the second embodiment has a bolt body 20 between the male screw portion 15 and the head 17 as a cylindrical body having a straight shape.

According to the second embodiment, as in the first embodiment, when the fastening bolt 14 is fastened to the ball joint 6, the diameter of the cylindrical portion 7 of the ball joint 6 is increased by the diameter-expanding component 18 and formed on the surface of the cylindrical portion 7. a plurality of protrusions 13 which are so bite the hole inner surface 5a of the lower arm portion 3 can be firmly fixed the ball joint 6 with respect to the lower arm portion 3. Therefore, according to the second embodiment, rattling of the ball joint 6 can be suppressed even when an excessive impact force more than expected is applied.

  In particular, in the second embodiment, since the diameter-expanded part 18 is formed as a separate part from the fastening bolt 14, even if the diameter of the hole 5 varies within the tolerance range, it corresponds to the variation in the diameter of the hole 5. By preparing multiple types of diameter-expanded parts 18 with different outer peripheral dimensions and selecting and using the diameter-expanded parts 18 according to the diameter of the hole 5, clearance adjustment such as hole tolerance can be adjusted to one type of bolt. On the other hand, it can respond by the difference in the size of the diameter-expanded component 18.

  Here, compared to the case where the tapered shape as in the first embodiment is formed integrally with the fastening bolt 14 itself and a plurality of types are prepared according to the hole tolerance, the second embodiment has a relatively simple shape expansion. This can be dealt with by the diameter component 18, and the cost can be reduced and the fastening can be surely performed.

  The ball joint fastening structure to which the present invention is applied has been described above. The structure of the present invention is applied to fasten the upper arm not only to the lower arm 3 of the knuckle steering 1 but also to the upper arm 2 with the ball joint 6. In addition, the structure of the present invention can be applied to all components such as a case where components other than automobile components are fastened with a ball joint.

  The present invention can be used to fix a ball joint with a fastening bolt in a hole of an attached object.

1 ... Knuckle steering (attachment)
2 ... Upper arm 3 ... Lower arm 4 ... Knuckle arm 5 ... Hole (hole formed in the lower arm)
6 ... Ball joint 8 ... Female thread part 9 ... Collar part 10 ... Spherical part 11 ... Slit 12 ... Tongue piece 13 ... Convex part 14 ... Fastening bolt (bolt part)
15 ... Male screw 16 ... Expanded part 17 ... Head 18 ... Expanded part (expanded part)

Claims (5)

A cylindrical portion having a plurality of convex portions on the surface to be inserted into the hole portion from one surface of the attachment object, a female screw portion formed on the inner surface of the cylindrical portion, and a collar provided on the proximal end side of the cylindrical portion A ball joint comprising a portion and a spherical portion provided on the collar portion;
A bolt portion that is screwed into the female screw portion in the cylindrical portion and fastens the ball joint to the attached object;
A diameter-enlarged portion that is inserted into the hole portion from the other surface of the attachment object, expands the diameter of the cylindrical portion by the fastening force of the bolt portion, and presses the convex portion against the inner surface of the hole portion. ,
The diameter-expanded portion has a shape that gradually increases in diameter from the distal end side to the proximal end side in the insertion direction into the cylindrical portion,
In the state where the entire cylindrical part between the collar part of the ball joint and the head part of the bolt part is located in the hole part of the attachment object,
The cylindrical portion is expanded in diameter by the expanded diameter portion, and the convex portion is pressed against the inner surface of the hole portion,
The object to be attached is clamped by fastening the female screw part and the bolt part from one side and the other side at the flange part of the ball joint and the head part of the bolt part. Characteristic ball joint fastening structure. The ball joint fastening structure according to claim 1,
The cylindrical joint has a slit formed from the distal end side toward the proximal end side, and a plurality of slits are formed in the circumferential direction of the cylindrical portion. A fastening structure for a ball joint according to claim 1 or 2,
The ball joint fastening structure, wherein the convex portion is formed as a ridge with a sharpened tip from the distal end side to the proximal end side of the cylindrical portion. A fastening structure for a ball joint according to any one of claims 1 to 3 ,
The ball joint fastening structure, wherein the enlarged diameter portion is formed integrally with the bolt portion. At least the ball joint fastening structure according to any one of claims 1 to 3 ,
The diameter-enlarged portion is formed as a separate component from the bolt portion and is attached to the bolt portion.

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