JPH0237286Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a bushing assembly that is interposed between a pivot and a cylindrical member constituting a vibration transmission system and connects them in a vibration-proof manner. This relates to a spherical sliding bushing assembly with a built-in sliding mechanism that effectively absorbs torsional and twisting forces applied between the pivot and the cylindrical member while connecting them in a vibration-proof manner. It is.

(Prior Art) Conventionally, a predetermined vibration isolating bushing has been interposed between a pivot shaft and a cylindrical member constituting a vibration transmission system.
The structure that connects these pivots and the cylindrical member with vibration isolation is
A variety of methods have been adopted. For example, in automobile suspensions, suspension members such as various arms, rods, and links are attached to be able to swing in various directions in order to suspend differential gears, wheels, etc. from the vehicle body. A suspension bush made of rubber material is generally incorporated into the pivot joint of a suspension member, that is, the pivot connection to the vehicle body, axle, or wheel side, for the purpose of mitigating vibrations. There is.

By the way, in a vibration-proof bushing such as such a suspension bushing, conventionally, there is an inner cylindrical metal fitting into which a predetermined pivot shaft is inserted, and an inner cylinder metal fitting disposed on the outside of the inner cylindrical metal fitting.
Generally, a structure in which a cylindrical elastic member is interposed between an outer cylindrical metal fitting fitted into a predetermined cylindrical member has been adopted, but in such a conventional bushing structure, If the rigidity in the direction perpendicular to the axis is increased with emphasis on anti-vibration performance, the torsional rigidity around the axis will also increase, impairing the rotational performance between the pivot and the cylindrical member, and conversely, increasing the rigidity in the direction perpendicular to the axis. It has been said that if the torsional rigidity around the axis is lowered in order to improve the rotational performance between the cylinder and the cylindrical member, the rigidity in the direction perpendicular to the axis will also be lowered, making it impossible to obtain good vibration isolation performance. There was a problem.

Therefore, in recent years, with the aim of solving such problems with conventional bushings, a predetermined sliding sleeve is fitted inside or outside the elastic member, and the elastic member is attached to the pivot or cylindrical member. Bush assemblies that can be easily rotated around an axis have been proposed. According to such a bushing assembly, it is possible to reduce the torsional rigidity between the pivot and the cylindrical member, regardless of the rigidity in the direction perpendicular to the axis of the elastic member, thereby improving vibration isolation performance and rotation performance. Both can be obtained in good condition.

(Problem) However, even with this improved bushing assembly, if a force is applied in a direction oblique to the bush axis, a so-called twisting force, the sliding movement of the sliding sleeve may be affected. There was a problem that the function was not fully expressed and the rotational performance between the pivot and the cylindrical member deteriorated.

On the other hand, in contrast to this, a so-called spherical sliding bushing assembly has been considered in which a spherical sliding mechanism is built inside the elastic member. By incorporating a spherical sliding mechanism inside the elastic member, the spherical sliding mechanism can absorb forces in the torsional and twisting directions, resulting in good rotational performance even when forces in the twisting direction are applied. Therefore, it is possible to stably obtain both good vibration damping performance and good vibration damping performance.

However, in this type of spherical sliding bush assembly, if foreign matter such as dirt, dust, or muddy water enters the spherical sliding part, the spherical sliding performance will be impaired, and the spherical sliding performance will be damaged. It is necessary to prevent foreign substances such as dust and muddy water from entering the spherical sliding part, as this will impair rotational performance.
To achieve this, it is necessary to seal the spherical sliding part from the outside space, but if such a sealing function is to be provided, the structure of the bushing assembly will be complicated, the number of parts will increase, and assembly will be difficult. There is a problem that the workability is reduced.
Particularly in the case of mass-produced products such as suspension bushings for automobile suspensions, the productivity was far from satisfactory.

(Solution Means) Against this background, the present invention has been developed to provide a sealing function to a spherical sliding part, which has excellent assembly workability and can reduce the number of parts as much as possible. This was made to provide a spherical sliding type bushing assembly, and its feature is that the bushing assembly is interposed between the pivot and the cylindrical member constituting the vibration transmission system as described above. and a bushing assembly for connecting them in a vibration-proof manner, (a) an inner cylindrical metal fitting having a spherical convex surface on an outer circumferential surface of an intermediate portion in the axial direction, into which the pivot shaft is inserted;
(b) a cylindrical race fitting arranged concentrically at a predetermined distance on the outside of the inner cylindrical fitting; and (c) a spherical concave surface corresponding to the spherical convex surface of the inner cylindrical fitting on the inner peripheral surface. a cylindrical sliding member whose spherical concave surface is slidably fitted into the spherical convex surface of the inner cylindrical fitting, and whose outer circumferential surface is fitted into the inner circumferential surface of the axially intermediate portion of the race fitting; , (d) a pair of presser sleeves that are respectively fitted into the inner circumferential surfaces of both ends in the axial direction of the race fitting and firmly clamp the sliding member in the axial direction of the bush; Annular seal lips arranged in the axial direction on the inner periphery are provided between the presser sleeves and the inner cylindrical metal fittings, respectively, and seal the annular gaps between the corresponding presser sleeves and the inner cylindrical metal fittings. A plurality of seals are provided, and are integrally attached to the inner circumferential surface of the sliding member side end of the corresponding presser sleeve at the outer circumferential portion, and are attached to the outer circumferential surface of the inner cylinder fitting at the annular seal lip of the inner circumferential portion. a pair of annular seal members that are elastically pressed;
(f) a cylindrical elastic member disposed on the outside of the race metal fitting to elastically hold the race metal fitting to the cylindrical member;

(Function/Effect) In such a spherical sliding bushing assembly, the inner cylinder fitting is slidably fitted and held on the spherical convex surface of the sliding member on the spherical concave surface. The torsional and twisting forces input between the cylindrical member and the cylindrical member are well absorbed by the spherical sliding between the spherical convex surface and the spherical concave surface. Since the elastic member is attached to the cylindrical member, good vibration damping performance can be obtained based on the elastic deformation action of the elastic member, regardless of the presence or absence of forces in the torsion and twisting directions.

Further, according to the spherical sliding bushing assembly according to the present invention, the annular gaps between the inner cylindrical metal fitting and each presser sleeve that clamps the sliding member in the axial direction are each closed by the sealing member. Since it is sealed, foreign matter such as dirt, dust, and muddy water can be effectively prevented from entering the spherical sliding area between the spherical convex surface and the spherical concave surface, thereby improving the spherical sliding performance and, ultimately, the shaft and cylinder. This effectively prevents the rotary performance between the seal member and the seal member from being impaired due to the intrusion of such foreign matter. Since it is integrally attached to the inner circumferential surface of the presser sleeve and is elastically pressed against the outer circumferential surface of the inner cylindrical metal fitting at a plurality of annular seal lips formed on the inner circumferential portion thereof, It has the advantage that the reliability of the sealing function is extremely high.

That is, even if the inner periphery of each seal member is made straight without providing an annular seal lip, and the straight inner periphery is elastically pressed against the outer periphery of the inner cylindrical metal fitting, Although a certain sealing effect can be obtained, in this case, when the inner cylinder fitting and the race fitting are displaced relative to each other in the twisting direction, there is a risk that the sealing member will buckle and the sealing function will be impaired. Therefore, it is difficult to say that the sealing effect can be stably obtained over a long period of time.

In addition, in the present invention, as described above, since the sealing member is attached to the inner circumferential surface of the end of the holding sleeve on the sliding member side, the sealing member is damaged due to relative displacement between the inner cylinder fitting and the race fitting. The deformation is extremely small, and the lifespan of the sealing member can be shortened accordingly.
Furthermore, there is an advantage that the bushing assembly has a long life.

Moreover, in the present invention, the outer circumferential portion of each seal member is attached to the presser sleeve for fixedly holding the sliding member as described above, so that The advantage is that the number of parts, and by extension the number of parts of the bushing assembly, can be reduced as much as possible, and due to its structure, the sealing member is connected to the presser sleeve, and the presser sleeve is connected to the race fitting. It can be attached before mounting on the inner cylinder metal fitting, and it is simply press-fitted onto the outer circumferential surface of the inner cylinder metal fitting, so it is easy to assemble. Therefore, good productivity can be obtained in addition to the effect of reducing the number of parts.

(Example) Hereinafter, in order to clarify the present invention more specifically, one example thereof will be described in detail based on the drawings.

First, FIG. 1 shows an example of a suspension bushing for an automobile suspension, which is a spherical sliding bushing assembly according to the present invention.
As shown therein, the suspension bushing of the present embodiment includes a cylindrical inner metal fitting 10 and a cylindrical metal fitting 10 that is concentrically arranged at a predetermined distance on the outside of the inner metal fitting 10. a lace fitting 12, a rubber sleeve 14 as an elastic member press-fitted to the outer circumferential surface of the race fitting 12, a cylindrical outer tube fitting 16 press-fitted to the outer circumferential surface of the rubber sleeve 14, and the lace fitting 12. a sliding sleeve 18 as a sliding member disposed between the metal fitting 12 and the inner cylinder metal fitting 10 and holding the inner cylinder metal fitting 10 in a spherically slidable manner;
The sliding sleeves 18 are attached to the inner peripheral surfaces of both ends of the race fitting 12 in the axial direction.
A pair of metal presser sleeves 20, 20 fixedly clamped in the axial direction with respect to 2, and an annular gap formed between these presser sleeves 20, 20 and the inner cylindrical fitting 10 are sealed, respectively. , a pair of annular seal rubbers 22, 22 as seal members.
It is composed of. In the inner hole 24 of the inner cylindrical metal fitting 10, it is attached to a pivot shaft (not shown) that constitutes a vibration transmission system, and on the outer circumferential surface of the outer cylindrical metal fitting 16, it is shown as a cylindrical member that also constitutes a vibration transmission system. It is installed by inserting it into the arm eye of a suspension arm that does not have a
These pivots and the arm eye of the suspension arm are connected in a vibration-proof manner.

Here, as shown in FIG. 2, the inner cylindrical metal fitting 10 is provided with a spherical convex surface 26 on the outer circumferential surface of the central portion in the axial direction, and on both sides of the spherical convex surface 26 in the axial direction. The outer circumferential surfaces of both ends thereof are cylindrical surfaces 28, 28.

The race fitting 12 also has thin caulked portions 30, 30 at both ends in the axial direction, as shown in FIG. 3 in its shape before the bushing is assembled.
At the center in the axial direction of the inner peripheral part thereof, over a length region approximately corresponding to the width of the spherical convex surface 26 of the inner cylindrical fitting 10, the inner diameter thereof is larger than that of the axially opposite regions. The small diameter part 3 is also made smaller.
2 (see Fig. 1), and has stepped surfaces 36 facing outward in the axial direction between the small diameter portion 32 and the large diameter portions 34, 34 on both sides in the axial direction. ing. The rubber sleeve 14 is press-fitted onto the outer peripheral surface of the race fitting 12, and the outer cylindrical fitting 16 is fitted into the band-shaped groove 38 formed on the outer periphery of the rubber sleeve 14. Press-fitted and fixed. Note that the rubber sleeve 14 is attached to the race fitting 12 and the outer cylinder fitting 1.
It is also possible to integrally fix it to one or both of the parts 6 by integral vulcanization molding, post-adhesion, or the like.

On the other hand, as shown in FIGS. 4 and 5, the sliding sleeve 18 has a spherical concave surface 40 corresponding to the spherical convex surface 26 of the inner cylindrical fitting 10 on the inner circumferential surface of the central portion in the axial direction. As shown in FIG. 1, the spherical concave surface 40 is slidably fitted to the spherical convex surface 26 of the inner cylinder fitting 10, and the small diameter of the race fitting 12 is fitted on the outer peripheral surface of the spherical concave surface 40. It is press-fitted into the section 32. Due to the slidable fitting between the spherical convex surface 26 and the spherical concave surface 40, the inner cylindrical fitting 10 and the sliding sleeve 18, and furthermore, the pivot shaft inserted through the inner cylindrical fitting 10 and the outer circumferential surface of the outer cylindrical fitting 16 are fitted. The arm eye of the suspension arm is able to slide spherically. In this embodiment, the length of the sliding sleeve 18 in the axial direction is set to be the same as that of the small diameter portion 32 of the race fitting 12,
As shown in FIG.
When the sliding sleeve 18 is fitted into the small diameter portion 32, both end surfaces of the sliding sleeve 18 in the axial direction are flush with the stepped surfaces 36, 36.

Further, as shown in FIGS. 4 and 5, a plurality of grooves 42 extending in the axial direction are formed on the inner peripheral surface of the sliding sleeve 18 at predetermined intervals in the circumferential direction. The presence of these grooves 42 allows the sliding sleeve 18 to be easily fitted into the inner cylinder fitting 10. Further, grease is normally applied to the spherical convex surface 26 and the spherical concave surface 40, and the groove 42 also functions as a grease reservoir.

Note that such a sliding sleeve 18 includes:
Generally, a resin material with a small coefficient of friction, such as nylon resin, polyacetal resin, or oil-impregnated polyacetal resin, is used.

Further, as shown in FIG. 6, each of the presser sleeves 20, 20 has a protrusion 4 located at one end in the axial direction and protrudes inward in the radial direction.
4, as shown in Figure 1,
The end surfaces on the side of the protrusions 44, 44 are the stepped surfaces 36, 36 of the race fitting 12 and the sliding sleeve 1.
8, the race fitting 12
It is press-fitted into the large diameter portions 34, 34 of. and,
The lace fitting 12 is fixed to the race fitting 12 by roll caulking of the caulking portions 30, 30 provided at both ends of the race fitting 12. Lace fittings 1
By being fixed to 2 in this manner, the sliding sleeve 18 is fixedly clamped in the axial direction, and the sliding sleeve 18 is fixed to the race fitting 12.

Furthermore, as shown in FIG. 7, the seal rubbers 22, 22 have a Y-shaped cross section with two annular seal lips 46 formed in a V-shape on the inner periphery thereof. the presser sleeve 20 at its outer periphery, that is, at the Y-shaped legs
At the same time, it is integrally attached to the protrusion portion 44 of the
The inner peripheral seal lips 46, 46 are elastically pressed against the cylindrical surface 28 of the cylindrical fitting 10, and the annular gap between the presser sleeves 20, 20 and the cylindrical fitting 10, that is, the spherical convex surface 26 and the spherical The spherical sliding portion between the concave surface 40 and the concave surface 40 is fluid-tightly sealed from the external space.

As shown in FIG. 6, the protrusion 44 of each presser sleeve 20 is formed with an annular groove 50 that opens on the inner circumferential surface, and each seal rubber 22 is As shown, the Y-shaped leg 48 on the outer periphery is accommodated in the annular groove 50, and the central part in the axial direction (of the presser sleeve 20) forming one side wall of the annular groove 50 is inserted into the annular groove 50. thin wall 52
By the caulking process, it is fixed integrally and fluid-tightly to the presser sleeve 20.
In addition, 2 formed on the inner circumference of each seal rubber 22
The annular sealing lips 46, 46 are pressed with a predetermined pressing force with their tip surfaces parallel to the cylindrical surface 28 of the cylindrical fitting 10, and the spherical convex surface 26 and the spherical concave surface 40 are pressed against each other with a predetermined pressing force. Race fitting 12 and inner cylinder fitting 1 based on spherical sliding
Even if there is a relative displacement between the inner cylindrical fitting 10 and the inner cylindrical fitting 10, its tip end surface is pressed against the outer circumferential surface (cylindrical surface 28) of the inner cylindrical fitting 10 with an appropriate pressing force.

Note that each seal rubber 22 has its outer peripheral leg portion 48 connected to each corresponding presser sleeve 20.
Before the presser sleeve 20 is attached to the race fitting 12, it is fixed by caulking.

In such a suspension bushing, the inner cylinder fitting 10 is slidably held on the spherical concave surface 40 of the sliding sleeve 18 at the spherical convex surface 26 on the outer circumference thereof, so that the pivot shaft and suspension constituting the vibration transmission system are Torsional or twisting forces applied between the arm and the arm eye are effectively absorbed by their spherical sliding motion. Therefore, irrespective of the presence or absence of forces in the torsional and twisting directions, a good vibration-proofing effect can be obtained based on the elastic deformation action of the rubber sleeve 14 against vibrations input between the pivot shaft and the arm eye. Can be done.

Further, according to the suspension bushing of this embodiment, as described above, the spherical convex surface 26 and the spherical concave surface 4
Seal rubbers 22, 22 for sealing the spherical sliding portion between the presser sleeve 20 and the presser sleeve 20 from the external space are fluid-tightly fixed to the inner circumferential surface of the presser sleeve 20 at the Y-shaped legs 48 located on the outer circumference, respectively. In addition, two seal lips 46, 46 formed on the inner circumference
Since the outer peripheral surface (cylindrical surface 28) of the inner cylindrical fitting 10 is constantly pressed with an appropriate pressing force, dirt, dust, muddy water, etc. are deposited on the spherical sliding portion between the spherical convex surface 26 and the spherical concave surface 40. The intrusion of foreign matter is reliably and stably prevented over a long period of time, and the rotational performance of the pivot and the arm eye of the suspension arm is maintained well over a long period of time. It is.

Further, in this embodiment, as described above, each seal rubber 22 is directly attached to the presser sleeve 20 for fixedly holding the sliding sleeve 18, and parts for assembling the seal rubbers 22, 22 are further provided. The number of parts, and by extension the number of parts for the suspension bushing, can be reduced.
In addition, each seal rubber 22 is attached to each presser sleeve 20, and the presser sleeve 20 is attached to the race fitting 12.
It can be installed before being attached to the
Since the inner cylindrical fitting 10 only needs to be press-fitted onto its outer circumferential surface, its assembly workability is also excellent. Therefore, it is possible to obtain good productivity in addition to the above-mentioned effect of reducing the number of parts.

Moreover, each seal rubber 22, as described above,
Since it is provided at the end of each presser sleeve 20 on the sliding sleeve 18 side, the amount of deformation due to relative displacement between the inner cylinder fitting 10 and the race fitting 12 is extremely small, and the seal rubber 22, 22 The advantage is that the life of the suspension bushing is long.

Further, in this embodiment, as is clear from FIG. 1, each pair of presser sleeves 20, 20 and seal rubbers 22, 22 have the same shape, so that they are compatible with each other. Therefore, in this respect as well, it has the advantage of being excellent in mass production.

Although one embodiment of the present invention has been described above, this is a literal illustration, and it goes without saying that the present invention should not be interpreted as being limited to this specific example.

For example, in the embodiment described above, the seal rubber 22 as a sealing member was caulked to each corresponding presser sleeve 20 at its outer peripheral portion, but the seal rubber 22 was crimped to the presser sleeve 20 by vulcanization adhesion. They may be integrally fixed.

Further, in the embodiment described above, two seal lips 46, 46 were provided in a V-shape on the inner circumference of each seal rubber 22, but the seal lips 46
may be provided in a U-shape on the inner peripheral portion of each seal rubber 22, or may be provided in three or more strips arranged in the axial direction.

Further, in the embodiment, each presser sleeve 20,
20 was fixed to the race fitting 12 by roll caulking of the caulking parts 30, 30 provided at the ends in the axial direction of the race fitting 12, but these presser sleeves 20, 20 It is also possible to simply fix it to the race fitting 12 by press fitting.

Further, in the embodiment described above, an outer cylindrical metal fitting 16 is further provided on the outside of the rubber sleeve 14 as an elastic member, and the suspension bushing is connected to the outer cylindrical metal fitting 16.
However, the present invention is not limited to this, and is applicable to a type of bushing in which the bushing is directly attached to a cylindrical member on the outer peripheral surface of the elastic member. It can also be applied.

Furthermore, in the above embodiment, an example was explained in which the present invention was applied to a suspension bush for an automobile suspension, but the present invention is not limited to this. It can be widely applied to bush assemblies that connect members with each other in a vibration-proof manner.

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

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view (a cross-sectional view parallel to the axis) showing an example of a suspension bushing for an automobile suspension according to the present invention, and FIG. 2 is a cross-sectional view showing the inner cylindrical metal fitting of the bushing. It is. FIG. 3 is a cross-sectional view showing the race fitting of the bush of FIG. 1 before the bush is assembled. FIG. 4 is a cross-sectional view (-cross-sectional view of FIG. 5) showing the sliding sleeve of the bush of FIG. 1, and FIG. 5 is a cross-sectional view thereof. 6 and 7 are cross-sectional views showing the holding sleeve and seal rubber of the bush of FIG. 1, respectively. 10: Inner cylinder metal fitting, 12: Race metal fitting, 14: Rubber sleeve (elastic member), 16: Outer cylinder metal fitting, 1
8: Sliding sleeve (sliding member), 20: Presser sleeve, 22: Seal rubber (sealing member), 26:
Spherical convex surface, 28: Cylindrical surface, 30: Caulked part, 4
0: Spherical concave surface, 44: Projection, 46: Seal lip, 50: Annular groove, 52: Thin wall.

Claims (1)

[Claims for Utility Model Registration] A bushing assembly that is interposed between a pivot shaft and a cylindrical member constituting a vibration transmission system and connects them in a vibration-proof manner, and has a spherical shape on the outer peripheral surface of the intermediate part in the axial direction. having a convex surface;
an inner cylindrical metal fitting through which the pivot shaft is inserted; a cylindrical race metal fitting concentrically arranged at a predetermined distance on the outside of the inner cylindrical metal fitting; and an inner peripheral surface corresponding to the spherical convex surface of the inner cylindrical metal fitting. a spherical concave surface, which is slidably fitted onto the spherical convex surface of the inner cylinder fitting;
a cylindrical sliding member fitted into the inner circumferential surface of an axially intermediate portion of the race fitting on its outer circumferential surface; and a cylindrical sliding member fitted into the inner circumferential surface of both ends of the race fitting in the axial direction; a pair of presser sleeves that fixedly clamp the bushing in the axial direction of the bush; and an annular gap provided between the pair of presser sleeves and the inner cylindrical metal fitting, respectively, between the corresponding presser sleeve and the inner cylindrical metal fitting. Seal each
The inner peripheral part includes a plurality of annular seal lips arranged in the axial direction, and the outer peripheral part is integrally attached to the inner peripheral surface of the end of the corresponding presser sleeve on the sliding member side. a pair of annular seal members that are elastically pressed against the outer circumferential surface of the inner cylindrical fitting at a circumferential annular seal lip; A spherical sliding bushing assembly comprising: a cylindrical elastic member for elastic holding.