JPH022105Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bushing assembly, and more particularly to a bushing assembly suitable for use in a pivot joint of a vehicle suspension.

Bushing assemblies used in pivot connections of vehicle suspensions, such as control arm bushings used in connections between control arms and vehicle bodies or unsprung members, are generally arranged concentrically. A cylindrical elastic member is interposed between two inner and outer cylindrical members, and the elastic force of the elastic member absorbs vibrations in a direction perpendicular to its axis. The torsional deformation about the axis of the cylinder allows relative rotation of both the inner and outer cylindrical members, that is, relative rotation of the connected member fixed to these cylindrical members.

By the way, in the conventional bushing assembly as described above, the rigidity in the direction perpendicular to the axis of the bushing assembly and the torsional rigidity around the axis are uniquely determined by the elasticity, shape, size, etc. of the elastic member. Therefore, it has been difficult to appropriately set the rigidity in the direction perpendicular to the axis and the torsional rigidity around the axis independently of each other in accordance with the characteristics required of the bushing assembly. In other words, in conventional bushing assemblies, if the rigidity in the direction perpendicular to the axis is increased with emphasis on vibration-proof performance, the torsional rigidity around the axis also increases and the relative rotation of the connected members is inhibited. On the other hand, if the rigidity around the axis was lowered to facilitate relative rotation of the connected members, the rigidity in the direction perpendicular to the axis would also be lowered and there was a risk that good vibration isolation performance could not be obtained. It is.

Therefore, in order to solve the problems of the conventional bushing assembly mentioned above, the applicants of the present application proposed in Utility Model Application No. 58-48872 to reduce the frictional resistance between the cylindrical member and the elastic member. We proposed a bushing assembly equipped with anti-friction means. According to this bushing assembly, the frictional resistance between the cylindrical member and the elastic member is reduced by the intervention of the friction reducing means, and the elastic member has a large rigidity in the direction perpendicular to the axis of the bushing assembly. Regardless of this, it is possible to relatively easily slide around the axis relative to the cylindrical member facing across the anti-friction means. In other words, it is possible to maintain good vibration damping performance while also making good relative rotation of the connected members.

However, in the bushing assembly improved in this way, the elastic modulus of the elastic member is made relatively large in order to obtain a predetermined vibration isolation performance, so that when the elastic member is deformed by an external force, There is a risk of muddy water entering the sliding part between the cylindrical member and the elastic member, and furthermore, the sliding part between the cylindrical member and the anti-friction means. If muddy water or the like enters the moving part, there is a risk that the good sliding function between the cylindrical member and the elastic member will be impaired, and the good relative rotation of the connected members will also be impaired.

Under these circumstances, the present invention aims to provide the improved bushing assembly described above, which can effectively prevent muddy water from entering the sliding parts. The main points of this work are that: an inner cylinder member;
an outer cylinder member disposed concentrically at a predetermined interval on the outside of the inner cylinder member; a cylindrical elastic member interposed between the inner cylinder member and the outer cylinder member; interposed between the cylindrical member and the elastic member,
anti-friction means for reducing frictional resistance therebetween, and located at both end portions of the elastic member in the axial direction, so as to be in contact with at least the inner cylinder member;
A sealing member made of a rubber-like elastic body having a smaller elastic modulus than the elastic member is arranged separately from the elastic member, and enters the friction reducing means from between the elastic member and the inner cylinder member. The reason is that it is designed to prevent muddy water from entering.

In this way, both the vibration isolation performance required of the bushing assembly and the rotation performance of the connected members connected via both the inner and outer cylindrical members can be set appropriately according to the purpose. The dynamic performance will not be impaired by muddy water or the like entering between the elastic member and the inner cylinder member. Moreover, according to the present invention, since the elastic modulus of the rubber-like elastic body constituting the seal member is made smaller than that of the elastic member, the elastic member is Even if the seal member is deformed, the seal member can sufficiently follow the deformation, and no gap is created between the seal member and the inner cylinder member, thereby effectively preventing entry of muddy water, etc. This is possible.

Hereinafter, in order to clarify the present invention more specifically, two or three embodiments thereof will be described in detail with reference to the drawings.

First, FIG. 1 shows an example of a bushing assembly according to the present invention, in which 2 is a cylindrical inner metal fitting, one opening end of which extends outward in the radial direction. The flange portion 4 is curved. A predetermined cylindrical sliding sleeve 6 made of oil-impregnated plastic or the like as a friction reducing means is slidably fitted on the outer peripheral surface of the inner cylindrical metal fitting 2. An annular stopper 8 defining an axial position between the flange portion 4 and the flange portion 4 is fixed in a fluid-tight manner by press-fitting. Note that this stopper 8 forms an inner cylinder member together with the inner cylinder metal fitting 2, and the end opposite to the sliding sleeve 6 is fixed flush with the opening edge of the inner cylinder metal fitting 2. Similarly, the end portion thereof is extended outward in the radial direction to form a flange portion 10 facing the flange portion 4 of the inner cylindrical fitting 2.

Further, a cylindrical elastic member 14 made of an elastic material having a relatively large elastic modulus is press-fitted onto the outer peripheral surfaces of the sliding sleeve 6 and the stopper 8. A cylindrical outer cylindrical fitting 16 as an outer cylindrical member is attached to the outer peripheral surface concentrically with the inner cylindrical fitting 2 by vulcanization adhesion or press fitting.

By the way, in this way, the inner cylinder fitting 2 and the elastic member 1
If a sliding sleeve 6 is interposed between the inner and outer cylinder members 4 and 4, which allows relative rotation between the two cylinder members, regardless of the elastic modulus of the elastic member 14, both the inner and outer cylindrical members, and the connected objects fixed to these cylindrical members, can be fixed. This allows for good relative rotation of the members, but the inner cylinder fitting 2
If muddy water or the like enters the sliding portion 17 between the sliding sleeve 6 and the sliding sleeve 6, good relative rotation thereof will be inhibited.
Therefore, in this embodiment, between the inner cylindrical member 2 and the elastic member 14, and between the stopper 8 and the elastic member 14, in other words, between the inner cylindrical member and the elastic member 14 on both sides of the sliding sleeve 6. Annular seals 18 and 20 are disposed between them, respectively, to prevent muddy water from entering the sliding portion 17.

That is, a seal 18 made of a rubber-like elastic body having an elastic modulus smaller than that of the elastic member 14 is adhesively fixed to the end of the elastic member 14 on the flange portion 4 side of the inner cylinder fitting 2. A seal 20 made of the same material as the seal 18 is adhesively fixed to a recess 22 formed at the inner peripheral edge of the opening at the end of the elastic member 14 on the stopper 8 side. is adapted to come into contact with the outer circumferential surface of the stopper 8 and the flange portion 10.

In this way, if the seals 18 and 20 made of a material with a smaller elastic modulus than the elastic member 14 are provided on the path through which muddy water or the like enters the sliding part 17, even if the elastic member 14 is deformed by external force, , sticker 1
Since the seals 8 and 20 can sufficiently follow the deformation, muddy water and the like will not enter the sliding portion 17 through the gap between the seals 18 and 20 and the inner cylinder member.

Note that in this embodiment, the seals 18, 20
is provided in a compressed state in the axial and radial directions of the bushing assembly, and the surface that abuts against the flange portion 4 of the inner cylindrical fitting 2 of the seal 18;
A ring-shaped uneven strip 24 centered on the axis of the bushing assembly is formed on the surface of the seal 20 that comes into contact with the outer peripheral surface of the stopper 8, so that the sealing effect can be more reliably exerted. There is.

Next, another embodiment of the present invention will be described based on FIG. In addition, in this embodiment, the sealing effect is more effectively exhibited when the inner cylinder member of the bushing assembly is fixed to the connected member.
This embodiment is different from the previous embodiment.

That is, in the bushing assembly shown in FIG. 2, the stopper 8 does not have the flange 10, and the flange 4 of the inner cylinder 2 merely functions to position the sliding sleeve 6 in the axial direction. The flange portion 4, the stopper 8, and the sliding sleeve 6 have the same outer diameter. On the other hand, the elastic member 14 has the same length as the inner cylindrical fitting 2, and has a concave portion 22 formed at the inner peripheral edge of the opening corresponding to the outer peripheral surfaces of the flange portion 4 and the stopper fitting 8. Seal 1 in recess 22
8 and 20 are fixed with adhesive. The grooves and grooves 24 are formed on the inner circumferential surfaces of the seals 18 and 20, and the grooves and grooves 24 are similarly formed on the side that forms part of the end face of the bushing assembly in the axial direction. be.

According to such a configuration, the seal 18 and the flange portion 4 of the inner cylinder fitting 2 are brought into contact with each other, and the seal 20
Not only does the sealing effect occur due to the contact between the retainer 26 and the stopper 8, but also the retainer 26 and the connected member are attached to the axial end surface of the bushing assembly when the inner cylinder member is fixed to the connected member. When the enlarged diameter portion is pressed, the sealing effect is also exerted by the contact between the seals 18 and 20 and the enlarged diameter portion of the retainer 26 and the connected member, which prevents muddy water from entering the sliding portion 17. Intrusion will be reliably prevented. In this case as well, it is desirable that the seals 18 and 20 be compressed in the axial direction and the radial direction, respectively, in order to exhibit even better sealing effects.

Although several embodiments of the present invention have been described above, these are literally illustrative, and the present invention should not be interpreted as being limited to these embodiments in any way.

For example, in the embodiment described above, each of the seal members (seals 18, 20) was provided with a portion thereof exposed at the end face in the axial direction of the elastic member 14, but it is not necessarily provided in such a state. It is not necessary that the elastic member 14 be placed in a ring-shaped recess that is opened only on the inner circumferential surface of the elastic member 14. However, in this case, it is necessary to adopt a structure in which the sealing member directly contacts the outer peripheral surface of the inner cylinder member.

Further, in the above embodiment, the seal member was adhesively fixed to the elastic member 14, but like the seal 20 in FIG. If there is no risk, it is not necessarily necessary to use adhesive and fixation.

Although not listed in detail, it goes without saying that the present invention can be implemented with various modifications and improvements without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing one example of a bushing assembly according to the present invention, and FIG. 2 is a view corresponding to FIG. 1 showing another example of the present invention. {2...Inner cylinder metal fitting, 8...Stopping metal fitting} (inner cylinder member), 4...Flange part, 6...Sliding sleeve (friction reduction means), 10...Flange part, 14...Elastic member, 16...Outer metal fitting, 17...Sliding part, 18,
20... Seal, 24... Uneven strip, 26... Retainer.

Claims (1)

[Claims for Utility Model Registration] (1) An inner cylinder member, an outer cylinder member disposed concentrically at a predetermined interval on the outside of the inner cylinder member, and the inner cylinder member and the outer cylinder member. a cylindrical elastic member interposed between the inner cylindrical member and the elastic member; and a friction reducing means interposed between the inner cylindrical member and the elastic member to reduce frictional resistance therebetween; A sealing member made of a rubber-like elastic body having an elastic coefficient smaller than that of the elastic member is provided separately from the elastic member so as to be located at both end portions in the axial direction of the member and in contact with at least the inner cylindrical member. A bushing assembly characterized in that the bushing assembly is arranged to prevent muddy water or the like from entering the friction reducing means from between the elastic member and the inner cylinder member. (2) The bushing assembly according to claim 1, wherein the sealing member has ring-shaped uneven stripes at least on the surface in contact with the inner cylinder member. (3) The bushing assembly according to claim 1 or 2, wherein the sealing member is compressed in the axial direction.