JP2002257127A - Ball join - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball joint which can be securely fitted without dropping out due to decrease of the connection strength of a supplying member. SOLUTION: A substantially cylindrical straight internal screw part 22 having an internal screw 21 at the peripheral face is formed in a lid 10 closing the insertion hole 8 of a body 9. A spot facing 23 on the coaxial axis, having a large diameter is formed in the straight internal screw part 22. A tapered external screw part 27 having a substantially cylindrical shape and an external screw 28 at the outer peripheral face and gradually tapered off in the diameteral direction toward the front end and provided with a distribution hole at the inner peripheral face, is fitted to a grease nipple 6. The tapered external screw part 27 is screwed in the straight internal screw part 22 until an incomplete screw part 29 where the external screw 28 of the tapered external screw part 27 is not formed comes into contact with the opening edge of the spot facing 23. The external screw 28 is screwed in the axial whole face of of the internal screw 21 to prevent the incomplete screw part 29 from unnecessarily being inserted in the straight internal screw part 22 and fitted thereto. Hence, the connection strength can be securely prevented from decreasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball joint having a supply member for supplying a lubricant into an inner chamber of a housing.

[0002]

2. Description of the Related Art Conventionally, as a ball joint of this type, for example, a configuration shown in FIGS. 4 and 5 is known.

The ball joint 60 shown in FIGS. 4 and 5 has a metal bottomed cylindrical housing 63 having an opening 61 at one end and an inner chamber 62 continuous with the opening 61. ing. The housing 63 has a substantially cylindrical body 65 having an opening 61 at one end and an insertion hole 64 larger in diameter than the opening 61 at the other end. Further, a plate-like lid 66 that is integrally attached to the body 65 by closing the insertion hole 64 is integrally attached to the body 65. The ball joint 60 includes a ball stud 69 having a substantially elongated cylindrical shaft portion 68 through which the opening 61 of the housing 63 can be inserted. At one end of the shaft of the ball stud 69, there is provided a substantially spherical ball head 70 that cannot be inserted through the opening 61 of the housing 63 but can be inserted through the insertion hole 64. Also,
In the housing 63, a bearing seat 72 made of a synthetic resin having rigidity and elasticity is housed. The bearing seat 72 has a substantially cylindrical shape in which an insertion hole 73 through which the shaft portion 68 of the ball stud 69 is inserted at one end and an approximately cylindrical oiling hole 75 which forms an oiling space 74 at the other end. The surface is formed in a spherical shape that slidably includes the ball head 70 of the ball stud 69. The cover 66 of the housing 63 is provided with a straight female screw portion 78 having a substantially cylindrical shape at substantially the center and a female screw 77 provided on the inner peripheral surface. The slate internal thread portion 78 is formed by a bearing seat housed in the housing 63.
It is provided at a position communicating with the lubrication hole 75 of the 72.

A grease nipple 81 for injecting grease or other lubricant (not shown) into the inner chamber 62 of the housing 63 is attached to the lid 66 of the housing 63. The grease nipple 81 has a substantially cylindrical shape having one end opened on one end surface in the axial direction and the other end opened on the outer peripheral surface on the other end side in the axial direction, and having a flow hole (not shown) for flowing oil and fat. The main body 82 has a shape of a circle. A tapered external thread portion 83 is provided on one end surface of the main body portion 82 in the axial direction. The tapered male screw portion 83 is formed in a substantially cylindrical shape whose inner peripheral surface communicates with the communication hole and whose outer peripheral surface gradually decreases in diameter toward the tip, and a male screw 84 is formed on the outer peripheral surface. The male screw 84 of the tapered male screw part 83 is not provided on the outer peripheral surface in the vicinity of the main body part 82 for the convenience of thread formation. The portion where the male screw is not provided is the incomplete screw portion 85.

A grease nipple 81 is screwed into a straight female screw portion 78 of the lid 66 of the housing 63, and a grease nipple is screwed into the lid 66 of the housing 63.
81 is fastened and attached.

[0006]

In the ball joint 60 shown in FIGS. 4 and 5, for example, the diameter of the tapered male screw portion 83 of the grease nipple 81 and the reduced diameter thereof, the thickness of the lid portion 66 of the housing 63, and the like. Due to dimensional errors such as the dimensions and the inner diameter of the straight female thread 78, the incomplete thread 85 at the base end of the tapered male thread 83 where the male thread 84 is not provided fits into the straight female thread 78 as shown in FIG. There is a possibility that a state may occur. This imperfect thread part 85
In the state where the straight female screw portion 78 is fitted, the fastening strength between the tapered male screw portion 83 and the straight female screw portion 78 decreases, and the grease nipple 81 may fall off.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a ball joint that can be securely attached without dropping due to a decrease in fastening strength of a supply member.

[0008]

According to a first aspect of the present invention, there is provided a ball joint having a ball stud provided with a shaft having a ball head at one end, and a slidable housing for the ball head. The bearing seat having an insertion hole to be inserted therein, the inner chamber for accommodating the bearing seat including the ball head of the ball stud and the shaft of the ball stud are inserted so that the ball head cannot be inserted. A ball joint comprising a housing having an opening opened to the inner chamber, and a supply member attached to the housing for supplying lubricant to the inner chamber, wherein the supply member has an external thread on an outer peripheral surface. The housing has a tapered male screw portion whose outer diameter is reduced toward the tip, and the housing has a substantially cylindrical storage tray provided with a female screw on the inner peripheral surface of which the tapered male screw portion of the supply member is screwed. A female screw portion and blocking means provided on at least one of the housing and the supply member for preventing a portion of the taper male screw portion of the supply member where the male screw is not provided from being inserted into the straight female screw portion. It is provided.

[0009] Then, a tapered male screw portion of a supply member provided with a male screw on the outer peripheral surface and having an outer diameter reduced toward the tip is screwed with a female screw of a substantially cylindrical straight female screw portion provided on the inner peripheral surface. The blocking means prevents the portion of the supply member where the male screw is not provided in the tapered male screw from being inserted into the straight female screw. This prevents a portion of the tapered male screw portion where the male screw is not provided due to excessively screwing the tapered male screw portion into the straight female screw portion from fitting into the straight female screw portion, thereby preventing a decrease in fastening strength.

According to a second aspect of the present invention, there is provided the ball joint according to the first aspect, wherein the blocking means is provided at an opening edge on an outer surface of the straight female screw opposite to the side where the ball stud is located. It is provided substantially coaxially with a diameter larger than that of the straight female screw portion, and has a counterbore portion into which the supply member cannot be inserted.

[0011] A counterbore is provided at the opening edge on the outer surface opposite to the side on which the ball stud of the straight female thread is located, substantially coaxially with the straight male thread and in which the supply member cannot be inserted into a large diameter. . This prevents the tapered male screw from being screwed too much into the straight female screw with a simple structure, and prevents the portion of the tapered male screw that is not provided with the male screw from fitting into the straight female screw, thereby reducing the strength of fastening. To prevent.

According to a third aspect of the present invention, in the ball joint according to the second aspect, the counterbore portion has a tapered external thread portion of the supply member in a state where the supply member is in contact with an opening edge on the outer surface side of the housing. The male screw is provided so as to be screwed into the entire surface of the female screw of the slate female screw portion in the axial direction.

In a state where the supply member is in contact with the opening edge of the counterbore portion on the outer surface side of the housing, the male screw of the tapered male screw portion of the supply member is screwed with the entire axial surface of the female screw of the straight female screw portion. And This reliably prevents a portion of the tapered male screw portion where the male screw is not provided due to excessively screwing the tapered male screw portion from fitting into the straight female screw portion, thereby preventing a decrease in fastening strength.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ball joint according to the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a ball joint,
The ball joint 1 is used for, for example, a suspension system or a steering system of an automobile. This ball joint 1
Is a housing 2 formed in a substantially cylindrical shape having a bottom with metal.
A ball stud 3 made of metal, a bearing sheet 4 made of synthetic resin, a dust cover 5 formed in a substantially cylindrical shape with rubber or soft synthetic resin, and a grease nipple 6 as a supply member. .

The housing 2 has an opening 7 at one end.
And a substantially cylindrical body portion 9 having an insertion hole 8 at the other end, and a substantially disk-shaped lid portion 10 for closing the insertion hole 8 is integrally attached to the body portion 9. ing.

The body portion 9 is provided with a cover attaching portion 11 in the form of a groove along the circumferential direction on the outer peripheral surface on the opening 7 side. A cover is provided on the inner peripheral surface of the body 9 on the side of the insertion hole 8.
The contact portion 12 is formed to have a large diameter so as to be substantially the same as the outer diameter of the contact 10, and the contact portion 12 is formed in a step shape. At the edge of the insertion hole 8 of the body 9, there is formed a locking portion 13 that engages with the peripheral edge of the lid 10 to hold it in place. Further, an arm (not shown) is provided on the outer peripheral surface of the body portion 9 so as to protrude in a substantially cylindrical shape integrally in the radial direction and is connected to another portion.

Further, the lid 10 is fixed to the body 9 in a state in which the outer peripheral end is held only in contact with the contact portion 12 and locked by the locking portion 13 after deformation. The housing 2 has a substantially bottomed cylindrical shape with an inner chamber 18 defined therein.

As shown in FIGS. 2 and 3, a substantially straight female screw part 22 having a substantially cylindrical shape and a female screw 21 formed on the inner peripheral surface thereof is provided substantially at the center of the lid part 10. Further, on the outer surface side of the lid portion 10, as a blocking means for preventing the grease nipple 6 from being inserted into the straight female screw portion 22 more than necessary and having a diameter larger than that of the straight female screw portion 22 substantially coaxially with the straight female screw portion 22. A functioning concave counterbore 23 is provided.

The cover 10 has a straight female screw
The grease nipple mounting portion 24 to which the grease nipple 6 is mounted is formed by the counterbore 22 and the counterbore 23. In addition,
The depth A of the counterbore 23 is smaller than half the thickness B of the lid 10.

The grease nipple 6 has a substantially cylindrical shape having a substantially L-shaped flow hole (not shown), one end of which is opened at one end in the axial direction and the other end is opened at the outer peripheral surface of the other end in the axial direction. The main body 26 has a shape like a letter. The main body 26 is formed in a size that cannot be inserted into the counterbore 23 of the lid 10, and functions as a blocking unit that prevents the grease nipple 6 from being inserted beyond a predetermined position.

Then, on one end face in the axial direction of the main body 26,
A tapered male thread 27 is provided. The tapered male screw portion 27 is formed in one end surface in the axial direction of the main body portion 26 in a substantially cylindrical shape whose diameter gradually decreases toward the tip, and a male screw 28 is formed on the outer peripheral surface. Also, the tapered male thread 27
On the other hand, an incomplete screw portion 29 which is a portion where the male screw 28 is not provided is provided at a base end portion close to the main body portion 26 for convenience of forming the male screw 28. Furthermore, in the main body 26,
The injection part 30 is provided in a flow hole opened on the outer peripheral surface.
The injection section 30 is formed in a substantially cylindrical shape whose inner peripheral surface communicates with the flow hole. The injection unit 30 can be attached with a hose or the like (not shown) for injecting a lubricant such as grease into the circulation hole of the main body 26.

The grease nipple 6 has a male screw 28 screwed over the entire surface of the female screw 21 of the straight female screw portion 22 of the lid 10 in the axial direction, and a tapered male screw portion 27 is fastened to the straight female screw portion 22 and attached. . The attached grease nipple 6 is in a state where the incompletely threaded portion 29 of the tapered male screw portion 27 abuts on the opening edge of the counterbore portion 23 of the lid portion 10 without fitting into the straight female screw portion 22. ing.

On the other hand, the ball stud 3 has a substantially spherical ball head 35 and a shaft portion 37 whose base end is continuous with the ball head 35 via a neck 36 having a small diameter. And, at the tip of the shaft portion 37,
An external thread 38 is provided. The center of the ball head 35 housed in the housing 2 is located on the center axis of the arm of the housing 2.

The bearing seat 4 is formed by a sheet member 41 formed of a substantially cylindrical synthetic resin having good bearing characteristics such as polyacetal resin and polyurethane resin and having high load-bearing rigidity and elasticity. It is configured.

The seat member 41 has an insertion hole 45 into which the ball head 35 of the ball stud 3 is inserted at one end in the axial direction and through which the shaft portion 37 is inserted. A substantially cylindrical lubricating space 48 is formed at the other axial end of the seat member 41 for accommodating a distal end portion of the tapered male screw portion 27 protruding from the lid portion 10.

Further, the dust cover 5 has a substantially cylindrical flexible deformation portion 51. A first fitting portion 52 is provided at one end in the axial direction of the flexible deforming portion 51 so as to fit into the cover mounting portion 11 of the housing 2 in a substantially annular shape. At the other end of the flexible deformation portion 51 in the axial direction, there is provided a second fitting portion 53 which is fitted to the shaft portion 37 of the ball stud 3 in a substantially annular shape. The flexible deformation portion 51 is provided with a discharge port (not shown) for discharging lubricant, air, and the like that have flowed into the inside. Note that the discharge port is always closed, and is opened due to an increase in internal pressure.

Next, a process of assembling and forming the ball stud of the above embodiment will be described with reference to the drawings.

The ball head 35 of the ball stud 3 is inserted into the bearing seat 4 through the insertion hole 45 and accommodated therein. When the ball head 35 is inserted, a lubricant may be applied to the outer peripheral surface of the ball head 35 or the inner peripheral surface of the bearing sheet 4 in advance.

Then, the shaft portion 37 of the ball stud 3 to which the bearing seat 4 is attached is inserted through the insertion hole 8 so as to protrude from the opening 7, and the ball head 35 together with the bearing seat 4 is inserted into the body 9. To accommodate.

Thereafter, the lid 10 is inserted from the insertion hole 8 of the body 9 to the contact portion 12 until the outer peripheral end contacts the contact portion 12.
Is crimped inward to lock the outer peripheral end, and the lid 10 is integrally assembled with the body 9 to form the housing 2.

Further, the grease nipple 6 is attached to the lid 10 of the housing 2. That is, the tapered male screw portion 27 of the grease nipple 6 is screwed into the straight female screw portion 22 until the incomplete screw portion 29 comes into contact with the opening edge of the counterbore portion 23 of the lid portion 10 and fastened.

The grease nipple 6 attached by this fastening does not fit into the straight female screw part 22 because the incomplete screw part 29 abuts on the opening edge of the counterbore part 23. Further, the tip end of the tapered male screw portion 27 is located in the lubrication space 48.

Then, the first fitting portion 52 of the dust cover 5
Is fitted to the cover mounting portion 11 of the housing 2, and the second fitting portion 53 is fitted to the shaft portion 37 of the ball stud 3, and the dust cover 5 is assembled.
Is assembled.

When replacing or replenishing the lubricant, a hose (not shown) or the like is attached to the injection portion 30 of the grease nipple 6, the lubricant is press-fitted, and flows into the lubrication space 48 through the flow hole. Due to the inflow of the lubricant, the lubricant located between the bearing seat 4 and the ball head 35 of the ball stud 3 and the like passes through the opening 7 of the housing 2 from the insertion hole 45 side of the bearing seat 4 to the dust cover 5. Flexible deformation part
Extruded into 51. Further, the lubricant pushed into the flexible deformable portion 51 of the dust cover 5 flows out by opening a discharge port (not shown), and is replaced or filled with the lubricant.

As described above, in the above-described embodiment, the female screw 21 to which the tapered male screw portion 27 of the grease nipple 6 having the external thread 28 on the outer peripheral surface and having the outer diameter decreasing toward the tip is screwed is formed. A substantially cylindrical straight female screw portion 22 provided on the surface is provided on the housing 2. Further, the grease nipple 6 is substantially coaxial with the opening edge on the outer surface side of the straight female screw portion 22.
The housing 2 is provided with a counterbore 23 having a diameter larger than that of the straight female screw 22 in which the grease nipple 6 cannot be inserted.

Thus, when the tapered male screw portion 27 of the grease nipple 6 is screwed into the straight female screw portion 22 of the lid 10 of the housing 2 and fastened, the imperfect screw of the grease nipple 6 is The part 29 comes into contact with the part. For this reason, the tapered male screw part 27 is screwed too much into the straight female screw part 22, and the incomplete screw part 29 in which the male screw 28 of the tapered male screw part 27 is not provided becomes the straight female screw part 22.
To prevent the screw from being inserted more than necessary
Can be prevented from being fitted into the straight female screw portion 22, and a decrease in fastening strength can be prevented.

Further, it is possible to prevent the incomplete screw portion 29 from being inserted more than necessary into the straight female screw portion 22 and to fit the incomplete screw portion 29 to the straight female screw portion 22 by using a simple counterbore. Since the prevention is performed at the portion 23, a decrease in the fastening strength can be easily prevented, and the manufacturability can be improved.

Then, with the grease nipple 6 in contact with the opening edge on the outer surface side of the housing 2, the grease nipple 6
The male thread 28 of the tapered male thread 27 is straight female thread 22
A counterbore 23 is provided so as to be screwed onto the entire surface of the female screw 21 in the axial direction. For this reason, the tapered male screw part 27 is excessively screwed into the straight female screw part 22 and
Of the incomplete screw portion 29 of the straight female screw portion 22 can be reliably prevented from decreasing.

Further, with a simple structure in which the counterbore portion 23 is provided,
Incomplete threaded part 29 due to excessive threading of tapered male thread part 27
Can be prevented from fitting into the straight female screw portion 22, so that the tapered male screw portion 27, the straight female screw portion 22,
Dimensional tolerance increases, and the yield can be improved.

Further, the depth A of the counterbore 23 from the outer surface of the lid 10 of the housing 2 is made smaller than half the thickness B of the lid 10. For this reason, while securing the fastening area between the tapered male screw part 27 and the straight female screw part 22, the tapered male screw part
The male screw 28 of the 27 can be screwed onto the entire surface of the female screw 21 of the slate female screw portion 22 in the axial direction to obtain a state in which a decrease in the fastening strength is prevented, and a reduction in the strength of the lid 10 can be prevented.

In each of the above embodiments, the ball joint 1 used for a suspension system, a steering system, and the like of an automobile has been described. Any one such as one having a part can be used.

Further, the configuration using the housing 2 for closing the insertion hole 8 of the body 9 with the lid 10 and accommodating the bearing seat 4 and the ball head 35 of the ball stud 3 has been described. A structure may be adopted in which the body 10 is provided integrally with the body portion 9 and the bearing seat 4 and the ball head 35 are accommodated through the opening 7 and then caulked and deformed so as to reduce the diameter of the opening 7.

Further, the one without the dust cover 5 may be used.

Further, the grease nipple 6 is connected to the housing 2.
The cover 10 is provided substantially at the center of the cover 10, but may be provided not only at the center but also near the periphery of the cover 10 or the outer peripheral surface of the housing 2.

[0046]

According to the ball joint according to the first aspect of the present invention, there is provided a blocking means for preventing a portion of the supply member where the male screw is not provided in the taper male screw portion from being inserted into the straight female screw portion. It is possible to prevent a decrease in the fastening strength due to the fact that the portion of the tapered male screw portion where the male screw is not provided and the male screw is not provided is fitted into the straight female screw portion.

According to the ball joint according to the second aspect, in addition to the effect of the ball joint according to the first aspect, the outer peripheral side opening edge of the straight female screw portion is supplied substantially coaxially with the straight male screw portion with a large diameter. In order to provide a counterbore part where the member cannot be inserted, with a simple structure, it is necessary to screw the tapered male thread part too much into the straight female thread part and to fit the part where the male thread of the tapered male thread part is not provided to the straight female thread part. And a decrease in fastening strength can be prevented.

According to the ball joint according to the third aspect, in addition to the effect of the ball joint according to the second aspect, the supply member abuts against the opening edge of the counterbore portion on the outer surface side of the housing. In order for the male thread of the tapered male thread to be screwed into the entire surface of the female thread of the straight female thread in the axial direction, the taper male thread is screwed too much and the part of the tapered male thread where the male thread is not provided is fitted to the straight female thread Therefore, a decrease in the fastening strength due to this can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a ball joint according to the present invention.

FIG. 2 is a cross-sectional view showing a lid to which the grease nipple is attached.

FIG. 3 is a cross-sectional view showing the upper cover.

FIG. 4 is a sectional view showing a conventional ball joint.

FIG. 5 is a cross-sectional view showing the upper cover.

FIG. 6 is a cross-sectional view showing a lid to which the grease nipple is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball joint 2 Housing 3 Ball stud 4 Bearing seat 6 Grease nipple as a supply member 7 Opening 18 Inner chamber 21 Female screw 22 Straight female screw part 23 Counterbore part as blocking means 27 Tapered male screw part 28 Male screw 35 Ball head 37 axis Part 45 Insertion hole

Claims (3)

[Claims] A ball stud provided with a shaft having a ball head at one end; a bearing seat having a ball hole slidably received therein and having an insertion hole through which the shaft is inserted; A housing having an inner chamber for accommodating the bearing seat enclosing the ball head of the ball stud, and an opening through which the shaft of the ball stud is inserted so that the ball head cannot be inserted into the inner chamber; A ball joint having a supply member attached to the housing for supplying lubricant to the inner chamber, wherein the supply member is provided with an external thread on an outer peripheral surface, and the outer diameter decreases toward the tip end The housing has a tapered male screw portion, and the housing has a substantially cylindrical straight female screw portion in which a taper male screw portion of the supply member is screwed and an internal thread is provided on an inner peripheral surface, and the housing and the supply member are provided. Ball joints is characterized in that a blocking means for preventing that the portion where the male screw is not provided in the tapered male thread portion of the feed member provided on one is inserted into the straight female thread portion even without. 2. The blocking means is provided at an opening edge on the outer surface of the straight female screw portion on the side opposite to the side on which the ball stud is located, substantially coaxially with the straight female screw portion and larger in diameter than the straight female screw portion, The ball joint according to claim 1, wherein the supply member has a counterbore portion that cannot be inserted. 3. The counterbore portion, in a state where the supply member is in contact with the opening edge on the outer surface side of the housing, the external thread of the tapered external thread portion of the supply member is screwed onto the entire axial surface of the internal thread of the slate internal thread portion. The ball joint according to claim 2, wherein the ball joint is provided in a state.