JPH0128357Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a bushing assembly suitable for being incorporated into a rotating pivot joint mainly in the suspension of an automobile, and in particular to a relative sliding part inside the bushing. This invention relates to an improvement in the seal structure that isolates the air from the outside.

BACKGROUND OF THE INVENTION Generally, a bushing assembly incorporated in a pivot joint of an automobile suspension such as the one described above, such as the ends of a leaf spring or the connecting end of a control arm, has inner cylinder fittings arranged concentrically with each other. It has a structure in which a cylindrical rubber elastic body is interposed between the outer cylinder metal fitting and at least one of between the inner cylinder metal fitting and the rubber elastic body and between the outer cylinder metal fitting and the rubber elastic body. A sliding means, such as a cylindrical resin sleeve made of oil-impregnated plastic, is usually provided to reduce the frictional force between them and allow relative sliding around the axis. Vibration in the direction perpendicular to the axis of the bushing assembly is alleviated by the rubber elastic body, and the sliding means provided inside the bushing assembly moves the shaft between the inner cylinder metal fitting and the outer cylinder metal fitting. It plays a role in allowing relative torsional movement around the heart.

By the way, in the past, such bushing assemblies were disclosed in, for example, Utility Model Application No. 57-184336 and Utility Model Application No. 55.
−40249, etc., where a flange or rib is formed by sandwiching a sliding means at both ends of a rubber elastic body, and the flange portion or rib is elastically deformed onto the outer peripheral surface of the inner cylindrical metal fitting or the inner peripheral surface of the outer cylindrical metal fitting. Structures are known in which they are brought into close contact with each other, or are made to face each other with a gap between them.

Problems to be solved by the invention However, regarding the seal structure in such a conventional bushing assembly,
No. 40249 could not sufficiently prevent muddy water from entering the relative sliding part, and
In the case of No. 184336, as mentioned above, the flange part and rib of the rubber elastic body that is brought into close contact with the inner and outer cylinder fittings slide between the inner and outer cylinder fittings, and as a result, There was a problem that the seal would wear out and lose its sealing effect.

Means for Solving the Problems The present invention provides the above-mentioned inner cylinder metal fittings, outer cylinder metal fittings,
This was done to solve the problems with conventional bush assemblies equipped with rubber elastic bodies and sliding means, and its feature is that the corresponding ends of the inner and outer cylinder fittings are made of rubber elastic bodies. an elastic cover body formed by connecting a concentric inner ring and an outer ring to an elastic member is press-fitted between the extension parts in the axial direction from the end face of the ring, The relative sliding portion by the sliding means is shielded from the outside.

Embodiments Hereinafter, in order to clarify the present invention more specifically, some embodiments of the present invention will be described in detail based on the drawings.

First, FIG. 1 shows a longitudinal sectional view of a bushing assembly which is an embodiment of the present invention. This bushing assembly includes a cylindrical inner tube fitting 10 and an outer tube fitting 12 that are arranged concentrically with each other, and a cylindrical rubber elastic body 14 is interposed between them. . The inner peripheral surface of this rubber elastic body 14 is vulcanized and bonded to the outer peripheral surface of the inner cylinder fitting 10, and a shallow wide annular groove 16 is formed in the outer peripheral surface of the rubber elastic body 14. A cylindrical oil-impregnated resin sleeve 18 made of oil-impregnated plastic as shown in FIG. 2 is press-fitted into the annular groove 16 as a sliding means. A relative sliding portion 20 is formed between the outer circumferential surface of the oil-impregnated resin sleeve 18 and the inner circumferential surface of the outer cylindrical fitting 12.
Relative rotation between the rubber elastic body 14 and the rubber elastic body 14 is allowed.

Both end portions of the inner tube fitting 10 and the outer tube fitting 12 that correspond to each other are extended outward in the axial direction from both end surfaces of the rubber elastic body 14 to form an extension portion 2.
2 and 24 are formed respectively, and the inner cylinder fitting 1
The extension parts 22 formed at both ends of the 0 have an outer diameter slightly smaller than that of the middle part thereof. Then, the extension part 22 of the inner cylinder fitting 10 and the outer cylinder fitting 12
An elastic cover body 26 as shown in FIG. 3 is provided between the extension part 24 and the extension part 24, respectively.
This elastic cover body 26 has a cylindrical inner ring 28 and an outer ring 30 arranged concentrically at a predetermined interval, and a circular thin rubber member 32 serving as an elastic member between them. By vulcanization molding, the inner ring 28 and the outer ring 30 have a structure in which they are integrally connected. The thin rubber member 32 covers the annular space between the inner ring 28 and the outer ring 30 by being vulcanized and bonded to the outer peripheral surface of the inner ring 28 and the inner peripheral surface of the outer ring 30, respectively. It is curved in a direction substantially parallel to the axis of the bellows and has a slack shape.
Note that after the thin rubber member 32 is vulcanized, the outer ring 30 is drawn in the radial direction, thereby making the outer ring 30 more loose.

The inner ring 28 of such an elastic cover body 26
is press-fitted into the outer circumferential surface of the extension portion 22 of the inner cylindrical fitting 10, and is also press-fitted into the inner circumferential surface of the outer cylindrical fitting 12 of the outer ring 30, whereby the oil-impregnated resin sleeve 18 and the outer cylindrical fitting 12 are The relative sliding portion 20 between them is shielded from the outside.

Further, the opening edges on both sides of the outer cylindrical fitting 24 are caulked to the press-fitted outer ring 30, so that the outer cylindrical fitting 12 of the outer ring 30
It is reliably prevented from coming off. The code 34 is
This is the caulking part. Furthermore, as is clear from FIG. 2, at both ends of the oil-impregnated resin sleeve 18,
A small diameter portion having a slightly smaller outer diameter is formed, and the inner open end surface of the outer ring 30 is positioned very close to the resulting shoulder surface 34, and these outer rings 30 are connected to the oil-impregnated resin sleeve. It also serves as means for preventing the rubber elastic body 18 from coming off from the rubber elastic body 14.

The bushing assembly configured as described above is suitably used for automobile suspension.
For example, the leaf spring is used with the outer cylindrical fitting 12 being press-fitted into pivot joints (spring eyes) at both ends of the leaf spring, while the vehicle body side shaft is inserted inside the inner cylindrical fitting 22. The rubber elastic body 14 alleviates vibrations that mainly act in a direction perpendicular to the axial direction, and the oil-impregnated resin sleeve 18
However, relative torsional displacement between the inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 12 is allowed in the relative sliding portion 20, but this relative sliding portion 20 is isolated from the outside by the elastic cover body 26. Therefore, there is no possibility that muddy water or other foreign matter will enter there and damage the relative sliding portion 20. In particular, the elastic cover body 26 is press-fitted between the extensions 22 and 24 of the inner and outer metal fittings 10 and 12 in the inner and outer rings 28 and 30, and
Since the thin rubber member 32 is vulcanized and bonded,
Compared to conventional products, there is no wear due to sliding, and much higher sealing performance is guaranteed for many years.

Further, the annular thin rubber member 32 is elastically twisted in the circumferential direction when the oil-impregnated resin sleeve 18 allows relative rotation between the inner cylindrical fitting 10 and the outer cylindrical fitting 12 at the relative sliding portion 20. However, since it is formed into a bellows shape with slack, it easily undergoes torsional deformation and follows the relative rotation between the inner cylindrical fitting 10 and the outer cylindrical fitting 12 well. Resistance can be kept low. Moreover, since the position of the oil-impregnated resin sleeve 18 in the center line direction is defined by the outer ring 30 of the elastic cover body 26, there is no need to use a special fastener, etc., and the structure is simplified. be.

Furthermore, another embodiment will be described based on FIG. 4. In this embodiment, the outer circumferential surface of the rubber elastic body 14 is vulcanized and bonded to the inner circumferential surface of the outer cylinder fitting 12, and an oil-impregnated resin is inserted into a shallow wide annular groove 16 formed on the inner circumferential surface of the rubber elastic body 14. The sleeve 18 is press-fitted,
The inner peripheral surface of this oil-impregnated resin sleeve 18 and the inner cylinder fitting 1
A relative sliding portion 20 is formed between the outer circumferential surface of 0 and the outer peripheral surface of 0. In addition, the inner ring 28 of the elastic cover body 26
are located very close to both end surfaces of the oil-impregnated resin sleeve 18, and define its position in the centerline direction. Since the other parts are the same as those in the previous embodiment, corresponding parts are given the same reference numerals and detailed explanations are omitted. Intrusion of muddy water and the like into the relative sliding portion 20 is effectively prevented for many years.

Note that instead of the elastic cover body 26 in the embodiment described above, an annular rubber member 38 (this is a soft rubber elastic body) having substantially no slack, as shown in the elastic cover body 36 shown in FIG. It is also possible to connect the inner rings 28 and 30 by a ring (preferably formed with It goes without saying that this will happen again.

Effects of the Invention As described in detail above, the present invention extends the mutually corresponding ends of the inner cylindrical metal fitting and the outer cylindrical metal fitting in the bushing assembly outward in the axial direction from the end surface of the rubber elastic body, and An elastic cover body consisting of a concentric inner ring and an outer ring connected by an elastic member is press-fitted between the extension parts, thereby preventing relative sliding inside the bushing assembly. It is possible to reliably prevent muddy water etc. from entering the moving parts for many years, and has the effect of improving the durability of the bushing assembly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a bushing assembly which is an embodiment of the present invention. FIG. 2 is a partially cutaway front view showing an oil-impregnated resin sleeve as a sliding means of the bush assembly. FIG. 3 is a longitudinal cross-sectional view showing the elastic cover body shown in FIG. 1 as a single item. FIG. 4 is a longitudinal sectional view of a bushing assembly according to another embodiment of the present invention, and FIG. 5 is a longitudinal sectional view showing still another embodiment of the elastic cover body. 10...Inner cylinder metal fitting, 12...Outer cylinder metal fitting, 14...
... Rubber elastic body, 18 ... Oil-impregnated resin sleeve (sliding means), 20 ... Relative sliding part, 22, 24 ... Extension part, 26, 36 ... Elastic cover body, 28 ... Inner ring, 30 ... Outer ring, 32... Thin rubber member (elastic member), 38... Rubber member (elastic member).

Claims (1)

[Claims for Utility Model Registration] (1) An inner cylindrical metal fitting and an outer cylindrical metal fitting are arranged concentrically with each other, and a cylindrical rubber elastic body is interposed between the inner cylindrical metal fitting and the outer cylindrical metal fitting. , and at least one of the inner cylindrical metal fitting and the rubber elastic body and the outer cylindrical metal fitting and the rubber elastic body to reduce the frictional force therebetween and to provide relative sliding around the axis. In a bushing assembly having a structure provided with a sliding means that allows movement, the mutually corresponding ends of the inner cylinder metal fitting and the outer cylinder metal fitting are extended outward in the axial direction from the end surface of the rubber elastic body, and An elastic cover body, which is formed by connecting a concentric inner ring and an outer ring with an elastic member, is press-fitted between the extension parts to block the relative sliding part caused by the sliding means from the outside. A bushing assembly characterized by the following features: (2) The bushing assembly according to claim 1, wherein the sliding means is a cylindrical oleoresin sleeve, and the inner ring or outer ring also serves as a means for preventing the oleoresin sleeve from coming off. . (3) The bushing assembly according to claim 1 or 2, wherein the elastic member of the elastic cover body is a bellows-shaped thin rubber member curved in the direction of the bush axis and having slack. (4) Utility model registration claims 1 to 3, wherein the extended end of the outer cylindrical metal fitting is caulked to the outer ring to prevent the outer ring from coming off. The bushing assembly described in any of the above.