JPH018735Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a resin bush that is fitted into a through hole of an object and into which a rotating shaft or the like is inserted. The present invention relates to an improvement in the assemblability of a resin bushing that is used with the flanges sandwiching the object from both sides.

Prior Art Such resin bushings are used, for example, as bearings to ensure smooth movement of shaft members and to suppress sliding noise. Conventionally, in order to assemble to an object, one flange 4 is made small in diameter and the flange 4 side is forcibly deformed elastically, as in the case of the resin bushing 2 shown in FIGS. 1 and 2, for example. The bush 2 was pushed into the through hole, but it was not easy to assemble and it was difficult to fit the bush 2 into the through hole with high accuracy. There was a problem that the smaller the diameter of the bushing 2, the easier it was for the bushing 2 to come off.

In addition, as a different type of resin bushing 6 shown in Figs. 3 and 4,
A wide crank-shaped slit 8 is formed from one end to the other, and by abutting the ends of the bush on both sides in the circumferential direction across the slit 8, the entire diameter of the bush 6 is penetrated. It was also possible to insert the hole with a diameter slightly smaller than the diameter of the hole, but when it is inserted into the through hole and restored to its original shape, there is a considerably wide slit 8 in the circumferential direction, so the rotation axis When supporting
It was unavoidable that the surface pressure in the area adjacent to the slit 8 would locally increase and the wear resistance there would deteriorate.

Purpose of the invention In view of the above-mentioned circumstances, the present invention aims to provide a resin bushing that can be assembled into a through hole of an object easily and without slipping out while keeping the slit width as small as possible. It was done for a purpose.

Structure of the invention The gist of the invention is to form a slit extending from one end of the bushing in the axial direction to the other end in a resin bushing having a cylindrical portion and a pair of annular flanges as described above. At the same time, at least one of the flanges of the pair is cut out from the portion where the slit is formed on one side in the circumferential direction with a dimension larger than the width of the slit.

Effects of the invention By doing this, when reducing the diameter of the flange for assembling the bushing, instead of having the ends in the circumferential direction butt against each other across the slit, it is possible to reduce the diameter of the flange. The diameter of the flange can be reduced without being restricted by the width of the slit by inserting the cut-out side inside the other and compressing the cylindrical portion while partially overlapping. In other words, in conventional bushings in which the flange was simply formed with a slit of the same width as the slit in the cylindrical part, even if one end was tried to be inserted inside the other end, the one end This is impossible because the flange of one end hits the other end, but
In the bushing according to the present invention, the flange is cut out with a width wider than the width of the slit as described above, so even if the bushing is rolled up as described above, the flange does not hit, and the bushing can be elastically compressed. It is possible. Therefore, the bushing can be narrowed beyond the width of the slit and within the width of the flange cut portion,
This makes it possible to fit into the through hole of the object more easily than in the past.

Moreover, the slit is sufficient as long as it allows the ends of the bushing to be rolled up with the slit in between, as described above, so the width of the slit when returned to its original shape after assembly is smaller than the conventional one. When used with a rotating shaft inserted inside the bush, the tendency for surface pressure near the slit to increase intensively is reduced, and wear resistance can be improved. It is.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 5 shows a bearing bracket 1 in which resin bushes 10 and 12, which are an embodiment of the present invention, are objects.
4 and 16 respectively assembled into through holes 18 and 20 formed in FIG. These bushes 10 and 12 function as bearings for the rotating shaft 22, and mainly serve to ensure smooth rotation of the rotating shaft 22 and to prevent sliding noise. The bearing brackets 14 and 16 are provided parallel to each other at a certain distance apart, and their through holes 18 and 20 are formed concentrically with each other, while both ends of the rotating shaft 22 are connected to the brackets 14 and 16 through the bushes 10 and 12, respectively.
16, and axial movement is prevented by a flange 24 formed at one end of the shaft 22 and a C-shaped retaining ring 28 attached to the other end via a spacer ring 26. has been done.
For example, a brake pedal of an automobile is attached to the rotating shaft 22, and the rotating shaft 22 is supported so as to be rotatable about its axis. Butsuyu 10, 12
The bushes 10 are different in size but have the same structure, so the bush 10 will be explained below.

This bushing 10 includes a cylindrical portion 30 and a pair of annular flanges 32 and 34 that protrude radially outward from the outer peripheral surface of both ends of the cylindrical portion 30. The bracket 14 is fitted in substantially tight contact with the bracket 14, and the pair of flanges 32 and 34 are attached to sandwich the bracket 14 from both sides. And the cylindrical part 30
A rotating shaft 22 is rotatably fitted onto the inner peripheral surface of the rotary shaft 22, and grease as a lubricant is applied to the sliding contact portion between the bush 10 and the rotating shaft 22 and the fitting portion between the bush 10 and the through hole 18, respectively. .

Such a bush 10 is made of a resin that is wear-resistant and capable of elastic deformation to a certain extent, such as polyacetal, polyamide, or polypropylene, and is taken out and shown in FIGS. 6 and 7. show.

As is clear from these figures, Bushu 10
has a slit 3 extending from one end to the other end in the axial direction.
6 is formed. This slit 36 divides not only the cylindrical portion 30 but also the flanges 32 and 34 at both ends, and as is clear from FIG.
It extends at an angle θ (for example, about 10 to 40 degrees) with respect to the generatrix of . One flange 32 is cut out from the part divided by the slit 36 on one side in the circumferential direction to form a cutout part 38 with a width wider than the width of the slit 36. The cutout portion 38 is formed at one end of the flange 32 facing clockwise in FIG. 6 from the end of the slit 36, and The flange 32 is completely removed in the area where the cutout portion 38 is formed, so that no portion that protrudes outward in the radial direction from the outer peripheral surface of the cylindrical portion 30 remains.

When assembling the bush 10 configured as described above into the through hole 18 of the bracket 14,
Push the bush 10 across the slit 36 as before.
Rather than abutting the ends in the circumferential direction, the end on the side where the cutout 38 is formed on the flange 32 side is inserted inside the other end, and the other end is placed outside the cutout 38. If the cylindrical part 30 is compressed elastically with the ends of the other flanges 34 shifted in the thickness direction and overlapped with each other, the diameter becomes smaller as shown in FIG. At least the outer diameter of the flange 32 is smaller than the inner diameter of the through hole 18. In this state, insert the bush 10 into the through hole 18 from the flange 32 side.
into the flange 3, and press the flange 34 to release the flange 3.
2 protrudes from the opening on the opposite side of the through hole 18,
If the partner flanges 32 and 34 are positioned at the openings at both ends of the through hole 18, the bush 10 will return to its original shape, allowing the bush 10 to be easily attached to the bracket 14 as shown in FIG. It can be assembled, and once it is assembled, it cannot be easily removed.

In the bush 10 of this embodiment, the slit 36 is provided to wind the cylindrical portion 30 into a small diameter as described above, and requires almost no width, so that it can be assembled into the through hole 18. The discontinuity of the cylindrical portion 30 in this state is slight. Moreover, since the slit 36 is not parallel to the generatrix of the cylindrical portion 30 but is inclined, the slit 36
No matter which part of the slit 36 is taken in the circumferential direction, the area for receiving the rotating shaft 22 is almost the same as the part without the slit 36. Therefore, even if the slit 36 exists, a local increase in surface pressure in the vicinity of the slit 36 is avoided, and wear resistance is improved.

Further, in this embodiment, the cutout portion 38 is formed only on one side of the flange 32, and the width of the cutout portion 38 is set to the minimum necessary. Even when grease is applied to the surface and the inner circumferential surface of the through hole 18, dripping of the grease can be minimized, and the ability to retain the grease is less likely to be impaired.

By the way, if the bush diameter is quite small, the slit 36 and the cutout part 38 as described above are
Even if it is formed, it may not be sufficient to elastically reduce the diameter. Therefore, as in the resin bushing 50 shown in FIG.
Furthermore, it is effective to form a plurality of slits 52 in the radial direction. In this embodiment, three slits 52 are provided at equal angular intervals and are formed deep enough to reach the outer peripheral surface of the cylindrical portion 30. In such a bush 50, the slit 52 is removed when the whole bush 50 is rolled up as in the above embodiment.
The presence of the bushing makes it easier to roll it up, and even if the bushing diameter is small, it can be easily reduced to the required diameter.

On the other hand, like the resin bushing 60 shown in FIG. 10, not only one flange 32 but also the other flange 34 is oriented in the same circumferential direction as the flange 32 side from the part where the slit 36 is formed. The cut portion 68 may be formed by performing a similar cut in the past. In this way, the partner flange 3
In the case of the bush 60 in which the cutouts 38 and 68 are formed on the parts 2 and 34, respectively, when assembled into the through hole,
It is not necessary to make the end portions of the flange 34 different from each other in the thickness direction as in the previous embodiment, and the diameter can be reduced by simply rolling the end portions into a cylindrical shape.

Furthermore, in the previous embodiments, the slit 36 was inclined with respect to the generatrix of the cylindrical portion 30;
Such an inclination is not an essential requirement, and even if the slit 36 is formed parallel to the generatrix, the slit 36 will not be tilted when assembled into the through hole and restored to its original shape. If the width is extremely small, the surface pressure near the slit 36 when receiving the rotating shaft 22 will hardly increase locally, and there will be no practical problem.

Although not described in detail, it is of course possible to implement the present invention in various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a specific example of a conventional bushing, and FIG. 2 is a front view thereof. FIG. 3 is a plan view showing yet another conventional bushing;
The figure is its front view. FIG. 5 is a cross-sectional view schematically showing how a resin bushing according to an embodiment of the present invention is used. FIG. 6 is a perspective view of the resin bush taken out, and FIG. 7 is a side view of the bush shown in FIG. 6. FIG. 8 is a side view showing the state in which the bush is assembled into the through hole. 9 and 10 are front views showing another embodiment of the present invention, respectively. 10, 12, 50, 60: Resin bushing, 1
4, 16: Bearing bracket (object), 18, 2
0: Through hole, 22: Rotation shaft, 30: Cylindrical part, 3
2, 34: Annular flange, 36: Slit, 3
8, 68: resection part, 52: slit.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical part and a pair of annular flanges protruding radially outward from the outer peripheral surface of both ends of the cylindrical part, and the cylindrical part is fitted into a through hole formed in an object. In a resin bushing that is fitted and used with a pair of flanges sandwiching the object from both sides, a slit is formed extending from one end of the bushing in the axial direction to the other end, and a slit is formed between the pair of flanges. 1. A resin bushing, characterized in that at least one of the slits is cut out on one side in the circumferential direction from the part where the slits are formed, with a dimension larger than the width of the slits. (2) The utility model according to claim 1, wherein the cutting is performed only on one of the pair of flanges, and the slit is formed at an angle with respect to the generatrix of the cylindrical portion. Resin bushing. (3) The resin bushing according to claim 1 or 2, wherein a plurality of radial slits are further formed in the cut flange.