JPH0524813Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] In the invention of the present application, an outer cylinder that supports a ball part so as to be slidable and rotatable via a bearing part made of hard resin is press-fitted into a press-fitting hole of a mating object. It concerns a type of joint configured as follows. In this specification, the above type of joint refers not only to a pillow ball bushing in which a stud part extends on both sides of the ball part, but also to a ball joint in which a stud part extends on one side of the ball part. Including int.

[Prior Art] As shown in FIG. 5, an outer cylinder 103 that supports a ball portion 101 so as to be slidable and rotatable in directions A, etc. via a bearing portion 102 is press-fitted into a press-fit hole 110 of a counterpart 104. A joint 105 constructed as follows is known. The joint 105 of FIG. 5 consists of a pillow ball bushing having a pillow ball 108 with stud portions 106, 107 extending on either side of the ball portion 101.
In this type of conventional pillow ball bushing 105, the outer cylinder 103 has a cylindrical outer peripheral surface 109 with a radius R0 before being press-fitted. On the other hand, opponent 1
The radius R1 of the press-fit hole 110 of No. 04 is smaller than the radius R0 of the outer periphery 109 of the outer cylinder 103 by a press-fit allowance B.

This press-fit type pillow ball bush 105
is press-fitted into the press-fit hole 110 of the mating member 104 in the direction of, for example, C in FIG.
05 is compressed and deformed in the radial direction inward D so that the outer diameter of the outer cylinder 103 matches the inner diameter 2·R1 of the press-fitted hole 110. Therefore, the outer cylinder 103 is
04 hole 110.

[Problem to be solved by the invention] However, in the case of the conventional pillow ball bushing as shown in FIG. 102 , and a force F due to this force E is further applied to the ball portion 101 of the pillow ball 105 via the bearing portion 102 .
As a result, the ball portion 101 of the pillow ball 108
The sliding friction between the ball part 101 and the bearing 102 becomes large, and there is a risk that the sliding rotation of the ball part 101 in the A direction or the like with respect to the bearing part 102 will be hindered, or that a large force will be required for the sliding rotation. . Further, due to variations in the dimensions of the press-fit allowance B, variations may occur in the force that presses the bearing 102 against the ball portion 101, and there is a possibility that variation may occur in the friction that resists the sliding rotation of the ball portion 101 against the bearing portion 102. In order to avoid such problems, the outer diameter of the outer cylinder 103 can be polished to a high degree of dimensional accuracy, and the other part 103 can be further cut after press finishing.
It is also necessary to form the inner diameter of the hole 110 of No. 04 with high dimensional accuracy, which not only takes time and effort to process but also increases the production cost.

In addition, in this type of conventional joint 105,
Due to compressive deformation of the outer cylinder when the outer cylinder 103 is press-fitted, the inner diameter of the outer cylinder decreases, and the bearing 102 and ball portion 10
In order to suppress an increase in friction between the outer cylinder 103 and the outer cylinder 103 as much as possible, the peripheral wall of the outer cylinder 103 is made thick. However, in this case joint 105
The outer diameter 2·R0 of the outer cylinder 103 becomes larger, and the press-fit hole 110 of the counterpart 104 also becomes larger accordingly, making it difficult to avoid an increase in the overall size and weight.

The present invention was developed in view of the above points, and its purpose is to ensure that the ball part can easily slide and rotate in the bearing part without the risk of the outer cylinder coming off from its counterpart. It is an object of the present invention to provide a relatively small press-fit type joint that can be easily processed and formed.

[Means for Solving the Problems] According to the present invention, the above-mentioned object is to provide the bearing support portion of the outer cylinder on the outer circumferential surface of the bearing support portion located on the radially outer side of the bearing portion during the press-fitting. An annular groove that allows expansion and deformation of a portion is provided over an axial range equal to or longer than the axial length of the bearing, and a press-fitting allowance is provided in a press-fitting portion of the outer cylinder other than the bearing supporting portion. It is achieved by doing so.

[Creation and Effects] In particular, in the joint of the present invention, when the outer cylinder is press-fitted, the outer circumferential surface of the bearing support part located on the radially outer side of the bearing part of the outer cylinder is deformed to expand the diameter of the bearing support part. Since the annular groove is provided over an axial range that is longer than the axial length of the bearing, when the outer cylinder is press-fitted into a mating object, there is a gap between the bearing part and the outer cylinder (more specifically, the bearing of the outer cylinder In other words, the annular groove on the outer circumference of the bearing support part of the outer cylinder is crushed in response to the force applied radially outward to the support part (in other words, the outer circumference of the outer cylinder and the press-fit hole of the counterpart) The bearing support portion of the outer cylinder is expanded in diameter (relative to the press-fit portion) so as to collapse the gap formed by the annular groove between the outer cylinder and the inner circumferential surface of the outer cylinder. As a result, after the outer cylinder is press-fitted, the press-fitted portion of the outer cylinder with the press-fit allowance is subjected to a radial compressive stress that provides a resistance force against the outer cylinder coming off in the axial direction (hereinafter referred to as "bushing removal force"). is applied to the outer cylinder from the other object, and even though the bearing is made of hard resin that can withstand relatively high loads, in the bearing support part of the outer cylinder, there is a radial force from the outer cylinder to the bearing part. Almost no inward force is added.
Therefore, in the joint of the present invention, the sliding rotation of the ball portion can be reliably supported by the bearing portion even if the outer circumferential surface of the outer cylinder and the press-fit hole are not machined with high precision. As a result, in the joint of the present invention, good sliding rotation performance and sliding rotation stability of the ball portion can be ensured.

On the other hand, in the joint of the present invention, a press-fitting allowance is provided in the press-fitting part of the outer cylinder other than the bearing support part (that is, the part of the outer cylinder located on the radial outside of the bearing part), so that the bushing removal force is reduced. However, even if the press-fitting interference is changed and the bushing withdrawal force is changed, the joint performance (sliding friction between the ball part and the bearing part) will not actually change due to the above-mentioned reasons. The force can be increased as desired.

[Embodiment] Next, a joint according to a preferred embodiment of the present invention will be described based on FIGS. 1 and 2.

In FIGS. 1 and 2, reference numeral 1 indicates a pillow ball consisting of a ball portion 2 and stud portions 3 and 4. The pillow ball 1 has flange-like protrusions 6 and 7 of the outer cylinder 5.
It is supported by its ball portion 1 so as to be slidable and rotatable in the A direction etc. by a bearing 8 installed between them. Note that in the drawings, for ease of viewing, the flange-like portions 6 and 7 are shown as if they are integral with the cylindrical peripheral wall 9 of the outer cylinder 5, but the flange-like protrusion portions 6,
At least one of the bearing parts 7 is removably attached to the inner surface 11 of the cylindrical peripheral wall part 9 (for example, in a groove (not shown) formed in the inner surface 11) so that the bearing part 8 can be attached and detached. It consists of a press-fitted ring or plug-like object. The outer peripheral surface 10 of the bearing part 8 has substantially the same dimensions and shape as the inner peripheral surface 11 of the peripheral wall 9 of the outer cylinder 5, and the inner peripheral surface 12 of the bearing part 8 has the same size and shape as the inner peripheral surface 11 of the peripheral wall 9 of the pillow ball 1. It has the same dimensions and shape as the surface 13. The bearing portion 8 is made of, for example, a hard resin such as nylon or polyacetal, or a resin having mechanical strength.

Radius R2 of the cylindrical outer peripheral surface 14 of the outer cylinder 5 in a state where no load is applied before the outer cylinder 5 is press-fitted
is larger than the radius R3 of the press-fit hole 16 of the mating member 15 by a press-fit allowance H limited by the bush removal force G. Here, if it is desired to increase the pulling-out force G, for example, if the lengths of the press-fit portions N and P are relatively short and there is a risk that the pulling-out force G will be small, the press-fitting allowance H may be increased. A generally cylindrical groove (annular groove) 18 is formed in a portion 17 of the outer circumferential surface 14 of the outer cylinder 5 located on the radially outer side of the bearing portion 8 . The axial length J of the groove 18 is slightly larger than the axial length K of the bearing portion 8, preferably
Longer than about 10%, both ends 1 in the axial direction of the groove 18
9 and 20 are located radially outward of the flange portions 6 and 7. For example, when the peripheral wall 9 of the outer cylinder 5 has a thickness of about 1.2 mm to 4 to 5 mm, the press-fitting allowance H is 0.05 mm.
It is about mm~0.075mm. The depth of the groove 18 may be any depth as long as it is not less than the press-fitting allowance H, unless the mechanical strength of the peripheral wall 9 of the outer cylinder 5 is extremely reduced. It should be noted that the depth of the groove 18 should be slightly smaller than the press-fitting allowance H as long as the force applied during press-fitting between the bearing part 8 and the ball part 2 of the pillow ball 1 can be made to a substantially negligible level. Good too. Note that since the groove 18 is shallow, it can be formed by cutting, rolling drawing, or the like.

In addition, in FIG. 2, 21 and 22 are boot parts for preventing foreign matter from entering the sliding contact parts 12 and 13 between the ball part 2 and the bearing 8, and 23 is a hole passing through the pillow ball 1. be. The through hole 23 may not be provided.

When the joint 24 of the preferred embodiment of the present invention configured as described above is press-fitted into the press-fit hole 16 of the counterpart 15, the pillow ball joint 2
4 is inserted into the press fit hole 16 from one end thereof in the L direction in FIG. A tapered portion (not shown) is provided at the insertion side end of the press-fitting hole 16 to guide insertion of the joint 24 in the L direction. Note that a tapered surface may be formed on the outer periphery of the insertion or press-fit side end 25 of the joint 24. When the outer cylinder 5 with the maximum radius R3 of the joint 24 is forcibly fitted in the L direction into the hole 16 with the radius R3 of the counterpart 15, the outer cylinder 5 is radially bent so that its outer diameter is substantially 2×R3. It is compressed and deformed inward. Therefore, joint 24
The outer cylinder 5 can be firmly held in the press-fitting hole 16 of the counterpart 15, that is, with a high bushing removal force G. On the other hand, along with this, the flange-like parts 6, 7 and the outer cylinder peripheral wall parts 25 on both sides of the flange-like parts 6, 7,
26 is also subjected to a stress indicated by M in a radially inward direction. However, in the joint 24, a groove 18 is provided in the outer circumferential surface portion 17 of the bearing support portion 27 located on the radially outer side of the bearing portion 8 in the outer cylinder 5, and the groove 18 is approximately the same depth as the press-fitting allowance H or deeper than the press-fitting allowance H. As a result, substantially no radially inward force is applied to the bearing support portion 27, or the radially inward force exerted on the portion 27 is weak and substantially negligible. Therefore, substantially no large force is applied to the sliding surfaces 12 and 13 between the ball portion 2 of the pillow ball 1 and the bearing portion 8.
The ball portion 2 of the pillow ball 1 can be slidably and rotatably supported by the sliding surfaces 12 and 13 that come into contact with the bearing portion 8. Moreover, in the joint 24, since the groove 18 is formed longer in the axial direction than the bearing part 8, the deformation of the peripheral wall 9 of the outer cylinder part 5 mainly occurs near the parts on both sides of the axial end of the bearing 8. 28,
Since the deformation of the peripheral wall 9 has almost no effect on the bearing part 8, even if the dimensional accuracy of the outer circumference of the outer cylinder 5 and the dimensional accuracy of the hole 16 of the counterpart 15 are not very high, the bearing part 8 and the ball portion 2 on the sliding contact surfaces 12 and 13, and the increase in sliding friction between the ball portion 2 and the bearing portion 8 can be minimized, and the performance of the joint 24 is improved. Stability may be enhanced. Therefore, the increase in sliding friction between the ball portion 2 and the bearing portion 8 after press-fitting can be minimized, and the magnitude of the friction after press-fitting can be adjusted at the time of design. In addition, even if there is some variation in the press-fitting allowance H, the outer cylinder peripheral wall 2 to which the press-fitting allowance H is added
5 and 26, the diameter reduction during press-fitting is not hindered by the bearing 8, so that variations in press-fitting load can be kept relatively small. Furthermore, in the joint 24, there is no need to increase the wall thickness of the outer cylinder 5 in order to avoid an increase in friction at the sliding contact portion of the ball portion 2.
The wall thickness of the outer cylinder 5 can be made thinner, and the joint 24 can be made smaller and lighter. Moreover, since the joint 24 can be miniaturized, when the joint 24 is applied to a suspension or the like, the degree of freedom of the vehicle body and suspension can be increased.

Note that, as long as the radially inward force applied to the bearing 8 when the joint 24 is press-fitted can be made substantially sufficiently small so as not to impede the sliding rotation of the ball portion 2, the groove 18 may be replaced by the groove shown in FIG. As shown in FIG. 2, a plurality of grooves 30 may be formed on the outer periphery of the outer cylinder 5 so that the outer circumferential surface of the bearing support portion 27 of the outer cylinder 5 has a corrugated shape 32 as a whole. In this case, as shown in FIG. 4, since the peak radial protrusion 31 between the adjacent grooves 30, 30 can be deformed with a relatively small force as it is press-fitted into the press-fit hole 16 of the outer cylinder 5, The pressing force on the sliding surfaces 12 and 13 between the bearing part 8 and the ball part 2 due to the press-fitting can be kept low, and the sliding rotation of the ball part 2 is not substantially hindered.

In addition, although the example in which the joint is made of a pillow ball has been described above, the joint may be made of a ball joint instead of the pillow ball.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory view showing a half portion of a pillow ball as a joint according to a preferred embodiment of the present invention, which is press-fitted into a press-fitting hole of a counterpart;
Fig. 2 is an explanatory cross-sectional view of the entire joint in Fig. 1, Fig. 3 is an explanatory cross-sectional view showing the groove of a modified example of the joint, and Fig. 4 is a press-fitting of the joint shown in Fig. 3 into the press-fit hole of the counterpart. FIG. 5 is an explanatory cross-sectional view similar to FIG. 1 showing a state in which a conventional joint is press-fitted into a press-fitting hole of a mating member. 2... Ball part, 5... Outer cylinder, 8... Bearing part, 15... Matching object, 18, 30... Groove, 2
4...joint, 32...corrugated groove (gathering part).

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A joint configured such that an outer cylinder that slidably and rotatably supports a ball part via a bearing part made of hard resin is press-fitted into a press-fitted hole of a mating member. In this step, an annular groove is formed on the outer circumferential surface of a bearing supporting portion located on the radially outer side of the bearing portion in the outer cylinder to allow expansion deformation of the bearing supporting portion during the press-fitting. A joint that is provided over an axial range of more than 300 mm, and has a press-fit allowance in a press-fit portion of the outer cylinder other than the bearing support portion. (2) The joint according to claim 1, wherein the groove comprises one annular groove 18 continuously formed in the entire axial direction of the bearing support portion of the outer cylinder. (3) The joint according to claim 1, wherein the groove is a wave-shaped groove 32 that extends in the axial direction of the entire bearing support portion of the outer cylinder in an axial direction.