JP2651973B2 - Fluid-filled cylindrical mount - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid-filled cylindrical mount capable of obtaining an anti-vibration effect based on the flow action of a fluid sealed therein, and is particularly suitably used as an engine mount or a suspension bush for an automobile. The present invention relates to a structure of a fluid-filled cylindrical mount to be used.

[0002]

2. Description of the Related Art Conventionally, as one type of vibration-proof connection or supporting device, an inner cylindrical metal member and an outer cylindrical metal member arranged at a predetermined distance in a radial direction from each other have a rubber elasticity interposed therebetween. 2. Description of the Related Art There is known a cylindrical mount having a structure connected by a body and capable of exerting an anti-vibration effect mainly against radial vibration input between the inner and outer cylindrical fittings. In addition, in order to improve the vibration isolation characteristics, a fluid chamber is formed between the inner cylinder and the outer cylinder to allow the enclosed fluid to flow (including resonance, shearing, and flow resistance). Various fluid-filled cylindrical mounts that utilize the vibration-proof effect exerted based on the above have been proposed.

In such a fluid-filled cylindrical mount, in order to facilitate fluid injection into a fluid chamber and obtain sufficient fluid tightness, generally, Japanese Patent Publication No. Sho 63-3 is used.
No. 763 and Japanese Unexamined Patent Publication No. 62-196434, etc., an inner cylindrical metal fitting and a metal sleeve arranged outside the metallic sleeve at a predetermined distance are interposed between the inner cylindrical metal fitting and a metal sleeve. By connecting with an elastic body, forming a pocket portion opened on the outer peripheral surface between the inner cylinder and the metal sleeve, and by externally fixing the outer cylinder to the metal sleeve, A structure in which the opening of the pocket portion is covered with a fluid-tight cover to form a fluid chamber is employed.

Further, in such a fluid-filled cylindrical mount, in order to obtain sufficient load characteristics and durability, a rubber elastic body constituting both side walls of the fluid chamber in the axial direction of the mount is provided.
It is desirable to be thick in the mount axis direction. However, if the outer peripheral edge of the rubber elastic body is made too thick,
When the rubber elastic body is swelled and deformed when a vibration load is applied, the rubber elastic body protrudes outward in the axial direction from the axial end face of the metal sleeve, and a crack or the like easily occurs due to the contact of the edge of the metal sleeve. There is a problem that.

Therefore, conventionally, as disclosed in the above-mentioned publication, generally, the radial outer peripheral edge of the rubber elastic body is made thinner in the axial direction to thereby reduce the axial outer peripheral edge of the rubber elastic body. The rubber elastic body protrudes from the axial end surface of the metal sleeve even if the rubber elastic body is swelled and deformed when a load is input by positioning the outer surface in the axial direction by a predetermined dimension from the axial end surface of the metal sleeve in the axial direction. I try not to.

However, a considerable internal stress is generated on the outer peripheral edge of the rubber elastic body when a load is input due to the fact that the deformation is regulated by the metal sleeve fixed to the outer peripheral surface. When the outer peripheral edge of the rubber elastic body is thinned as described above, the generated stress acts intensively on the outer peripheral edge of the thinned rubber elastic body. For this reason, cracks and the like are likely to occur at the outer peripheral edge of the thinned rubber elastic body, and there is an inherent problem that it is difficult to ensure sufficient durability.

[0007]

The present invention has been made in view of the above-mentioned circumstances, and a problem to be solved is to concentrate on an outer peripheral edge of a rubber elastic body in a fluid-filled cylindrical mount. And to improve the durability of the rubber elastic body and hence the mount.

[0008]

A feature of the present invention to solve such a problem is that an inner cylinder and a metal sleeve disposed outside the inner cylinder with a predetermined distance are interposed therebetween. And the outer sleeve is externally fitted and fixed to the metal sleeve to cover a pocket portion formed on the outer peripheral surface formed between the inner sleeve and the metal sleeve. Thereby, in the fluid-filled cylindrical mount in which a fluid chamber is formed between the inner cylinder and the outer cylinder, the rubber elastic body that constitutes both side walls in the axial direction of the mount in the fluid chamber is provided. a peripheral portion, said mounting
The outer surface of the mount axial direction extends in the direction perpendicular to the mount axis over the entire length in the circumferential direction of both side walls in the axial direction, and a band-shaped surface extending in the circumferential direction at a predetermined width along the inner peripheral surface of the metal sleeve. In addition to the thick part, the band shape in the thick part
Curved in the axial section of the mount by connecting to the inner peripheral edge of the surface
A recess recessed with a concave shape, the mounting axial both
Along the inner peripheral side of the band-shaped surface of the side wall,
By continuously providing the entire side wall portion in the circumferential direction , the inner peripheral portion adjacent to the thick portion can be mounted on the mount.
This is because the wall is thinnest at both axial side walls .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 show an FF type vehicle engine mount as one embodiment of the present invention. In these figures, reference numerals 10 and 12 denote an inner cylindrical fitting and an outer cylindrical fitting, which are arranged at a predetermined distance from each other in a radial direction, and are provided with a rubber elastic body 14 interposed therebetween. Linked to each other. And
Such an engine mount is mounted on a vehicle by attaching the inner cylinder fitting 10 and the outer cylinder fitting 12 to one of the vehicle body side and the power unit side, respectively. Let me support vibration proof. At the time of such mounting, the power unit weight and the vibration load are mainly input in one radial direction corresponding to the vertical direction in FIG. 2, and the rubber elastic body 14 is elastically deformed by the power unit weight. , Inner and outer cylinder fittings 10, 1
2 will be positioned substantially concentrically.

More specifically, the inner cylindrical fitting 10 has a thick cylindrical shape. A substantially circular rod-shaped support member 16 and a substantially groove-shaped stopper member 18 protrude outward on both sides facing in one radial direction at a central portion in the axial direction of the inner cylindrical member 10. In this state, it is fixed by welding or the like.

A metal sleeve 20 is disposed radially outward of the inner tube fitting 10 at a predetermined distance.
The metal sleeve 20 is separated from the inner cylindrical fitting 10 in the radial direction in which the support fitting 16 and the stopper fitting 18 are opposed to each other, on the support fitting 16 side, and approaches in the stopper fitting 18 side. Are arranged eccentrically by a predetermined amount.

A rubber elastic body 14 is interposed between the inner cylindrical fitting 10 and the metal sleeve 20. The rubber elastic body 14 allows the two fittings 10, 20 to be elastically attached to each other. Are linked. That is, the rubber elastic body 14 is formed as an integrally vulcanized molded product including the inner cylinder fitting 10 and the metal sleeve 20.

The metal sleeve 20 constituting such an integrally vulcanized molded product has a small-diameter portion 22 in which both ends in the axial direction have a larger diameter over a predetermined width than the central portion in the axial direction.
And a large-diameter portion 24, 24. A seal rubber layer 26 is formed integrally with the rubber elastic body 14 on the outer peripheral surface of the small diameter portion 22.

Further, a first window portion 28 is formed on one side of the metal sleeve 20 in the eccentric direction with respect to the inner cylinder fitting 10, and a second window portion 30 is formed on the other side in the eccentric direction. I have. Furthermore, a first pocket portion 32 and a second pocket portion 34 are formed in the rubber elastic body 14 at portions corresponding to the first and second windows 28 and 30 provided in the metal sleeve 20. ing. The first pocket 32 and the second pocket 34 are opened to the outer peripheral surface through the first window 28 and the second window 30.

Further, inside the first pocket portion 32, the support bracket 16 is positioned so as to protrude outward from the inner cylindrical bracket 10 side, and is supported by the support bracket 16. Thereby, the plate-shaped umbrella bracket 36 is
The support bracket 16 is disposed so as to extend in a direction perpendicular to the direction in which the support bracket 16 projects. Thus, an annular constricted portion 48 is formed between the outer peripheral edge of the umbrella fitting 36 and the inner peripheral surface of the first pocket portion 32. In addition, this umbrella bracket 3
A cushion rubber 38 is provided on the outer surface of 6.

Further, a space 40 extending axially through the rubber elastic body 14 is formed between the second pocket portion 34 and the inner cylindrical metal fitting 10 on the bottom surface of the second pocket portion 34. It is provided along. Then, the bottom wall 42 of the second pocket portion 34 is thinned by the space 40,
The deformation is easily tolerated. In addition, in such a bottom wall 42, only a circumferential central portion located opposite to the stopper fitting 18 with the space 40 interposed therebetween,
It is thickened to form the cushion rubber portion 44.

The seal rubber layer 26 provided on the outer peripheral surface of the metal sleeve 20 has a single recess extending in the circumferential direction between the first window 28 and the second window 30. A groove 46 is formed. The opening of the first pocket 32 and the opening of the second pocket 34 are connected to each other by the concave groove 46.

The outer vulcanized metal fitting 12 is externally inserted into the integrally vulcanized molded product having such a structure, and is fitted and fixed to the outer peripheral surface of the metal sleeve 20 to thereby obtain the first vulcanized product. The openings of the pocket portion 32 and the second pocket portion 34 are covered to form a pressure receiving chamber 50 and an equilibrium chamber 52 in which a predetermined incompressible fluid is sealed, respectively. The surface opening is covered, and an orifice passage 54 that connects the pressure receiving chamber 50 and the equilibrium chamber 52 to each other is formed. In the present embodiment, in order to effectively obtain a vibration damping effect based on the resonance action of the fluid flowing through the orifice passage 54 and the constricted portion 48,
As the sealed fluid, a low-viscosity fluid such as water, alkylene glycol, polyalkylene glycol, silicone oil,
It will be suitably used.

Incidentally, in such an engine mount, the input load is applied as a radial compression load to the rubber elastic body 14 constituting the peripheral wall of the pressure receiving chamber 50. There, such rubber elastic body 14
Of these, the pressure receiving chamber 5 that mainly shares the input load
As shown in FIG. 1, each of the vertical wall portions 56 on both sides in the axial direction of the mount at 0 has a substantially trapezoidal cross section that gradually becomes thinner from the inner cylinder fitting 10 side to the metal sleeve 20 side. It is formed with a shape.

The outer peripheral edge of each vertical wall portion 56 has a thickness such that the axially outer surface thereof is positioned inwardly in the axial direction by a predetermined dimension: l from the axial end surface of the metal sleeve 20. And is vulcanized and bonded to the inner peripheral surface of the metal sleeve 20. Thereby, even when the rubber elastic body 14 is deformed at the time of load input,
The protrusion of the rubber elastic body 14 outward from the metal sleeve 20 in the axial direction is avoided, so that damage to the edge of the metal sleeve 20 can be prevented.

Further, the axially outer side of each vertical wall portion 56, the outer peripheral edge portion thereof spreads in the axis-perpendicular direction, along the inner peripheral surface of the metal sleeve 20, a substantially constant width: at b, vertical Wall
A belt-like surface 58 extending continuously over the entire circumferential direction of 56
It has been. The band-shaped surface 58 makes the outer peripheral edge portion of the vertical wall portion 56 a thick portion 60 having a substantially constant thickness over the entire circumferential direction .

Further, the belt-like surface 5 of each vertical wall portion 56
8 is provided on the inner peripheral side in the cross section in the mount axial direction shown in FIG.
The belt has a curved concave shape that is concave with a curved concave surface , and is continuously connected to the inner peripheral edge of the belt-shaped surface 58 to form the belt.
Along the surface 58 , a groove-shaped recess 62 extending in the circumferential direction over the entire circumference of the band-shaped surface 58 is formed. And
Due to the concave portion 62, an inner peripheral portion adjacent to the thick portion 60 is a thin portion 64 thinner than the thick portion 60.

In short, in each vertical wall portion 56, the thick portion 60 is formed along the inner peripheral surface of the metal sleeve 20, so that the portion having the smallest axial thickness (the thin portion 64). However, it is positioned radially inward of the metal sleeve 20 at a position separated by the width b of the belt-shaped surface 58. And, thereby, the vertical wall portion 5
In 6, a shape stress concentration effect is produced at the portion where the thin portion 64 is formed.

Therefore, in the engine mount having such a structure, when a supporting load or a vibration load is input, the rubber sleeve 14 is restrained (deformation-prevented) by the metal sleeve 20 or the like. The stress concentrated on the outer peripheral edge of the elastic body 14 is effectively released to the thin portion 64 by the stress concentration effect of the thin portion 64, and the local concentration of the stress is advantageous. Can be alleviated or eliminated.

Moreover, when the stress at the outer peripheral edge of the rubber elastic body 14 is released to the thin portion 64, the stress is dispersed based on the elastic action of the thick portion 60 provided therebetween. Therefore, local stress concentration on the thin portion 64 can be effectively prevented, and as a result, diffusion of the generated stress to a wide range can be achieved.

Therefore, according to the engine mount having the above-described structure, the load characteristics and durability can be significantly improved.

In this case, the width b of the band-shaped surface 58 in the thick portion 60 is too small, so that the stress dispersion effect of the thick portion 60 is not effectively exerted. Radial dimension (difference between the outer peripheral surface of the inner cylinder fitting 10 and the inner peripheral surface of the metal sleeve 20): It is desirable to set the value to be 10% or more of r. It is desirable to set it to be 3 mm or more.

On the other hand, if the width b of the band-shaped surface 58 in the thick portion 60 is too large, the effect of transferring the stress by the thin portion 64 is difficult to exert, so that the rubber elastic body 14 generally has a radial dimension. : It is desirable to set the value to 20% or less of r.

Although the embodiments of the present invention have been described in detail, these are literal examples, and the present invention is not construed as being limited to such specific examples.

For example, in the above embodiment, the metal sleeve 2
Although a cylindrical shape having a large diameter portion 24, 24 at both ends in the axial direction was used as 0, a cylindrical shape having no such a stepped portion was similarly used. It goes without saying that it can be used.

The specific shape and number of the orifice passages 54 should be changed as appropriate according to the anti-vibration characteristics required for the mount, and are limited to those of the embodiment. is not.

Further, in the above-described embodiment, the fluid chamber is constituted by the pressure receiving chamber 50 and the equilibrium chamber 52 in which the internal pressure fluctuation is caused at the time of the vibration input. In addition, the internal pressure fluctuation is caused at the time of the vibration input. One having a plurality of pressure receiving chambers, one having three or more fluid chambers, or a single fluid chamber in which a high-viscosity fluid is sealed to obtain a damping effect by shearing action of the high-viscosity fluid What you did,
The invention can be applied as well.

According to the present invention, in such various types of cylindrical mounts, the above-mentioned axial side walls of at least one fluid chamber (pressure-receiving chamber) to which a supporting load or a vibration load is applied. Such a band-shaped surface 58 and a concave portion 62 are provided, so that a thick portion 60 and a thin portion 64 are formed.

In short, according to the present invention, at least one fluid chamber is formed by covering a pocket portion opened on the outer peripheral surface of a metal sleeve with an outer cylinder, and the wall portions on both axial sides of the fluid chamber are formed. It should be understood that any of these can be effectively applied to a fluid-filled cylindrical mount having a structure composed of a rubber elastic body. In addition, a variable-capacity equilibrium chamber communicated with the fluid chamber through an orifice passage may be formed by partitioning the interior of the fluid chamber, or may be located at a position circumferentially separated from the fluid chamber. It is needless to say that the present invention can be similarly applied to, for example, those formed between the inner sleeve and the metal sleeve.

Further, in the above embodiment, the metal sleeve 2
Although 0 is formed with a single cylindrical structure, it is also possible to use a metal sleeve composed of a plurality of divided bodies divided in the axial direction or the circumferential direction.

In addition, in the above-described embodiment, a specific example in which the present invention is applied to an engine mount for a vehicle has been described. However, the present invention is also applicable to a suspension bush for a vehicle, a differential mount, etc. Any of these can be applied to various types of cylindrical mounts in the above device.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[0039]

As is apparent from the above description, the fluid-filled cylindrical mount having the structure according to the present invention concentrates on the outer peripheral edge of the rubber elastic body when a supporting load, a vibration load, or the like is input. Since the locally induced stress is effectively released to the thin portion and is dispersed by the thick portion, the generated stress is diffused over a wide range, and local concentration can be eliminated or prevented. It will be.

As a result, the load characteristics and durability of the rubber elastic body, and consequently the cylindrical mount, can be extremely effectively improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an engine mount as one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the engine mount shown in FIG.

FIG. 3 is a side view of the engine mount shown in FIG. 1;

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 10 Inner cylinder fitting 12 Outer cylinder fitting 14 Rubber elastic body 20 Metal sleeve 50 Pressure receiving chamber 52 Equilibrium chamber 54 Orifice passage 56 Vertical wall 58 Band-shaped surface 60 Thick part 62 Depression 64 Thin part

Claims (1)

(57) [Claims] An inner cylinder and a metal sleeve disposed outside the metal sleeve at a predetermined distance are connected by a rubber elastic body interposed therebetween, and the outer sleeve is connected to the metal sleeve. By externally fitting and covering a pocket portion formed on the outer peripheral surface formed between the inner cylindrical member and the metal sleeve, thereby forming a fluid chamber between the inner cylindrical member and the outer cylindrical member. in forming fluid-filled cylindrical mount comprising a outer peripheral edge portion of the rubber elastic body constituting the mounting shaft opposite sides walls of said fluid chamber, said mounting shaft opposite sides walls
Along the entire length in the circumferential direction of the portion, the outer surface in the mount axial direction extends in the direction perpendicular to the mount axis, and forms a thick portion that is a band-shaped surface extending in the circumferential direction at a predetermined width along the inner peripheral surface of the metal sleeve. , The inner peripheral edge of the band-shaped surface in such a thick portion
Section and has a concave concave shape in the mount axial section.
The recessed concave portion is formed into a band-shaped surface on both side walls in the mount axial direction.
Along the inner peripheral side of the peripheral direction of both side walls in the axial direction of the mount.
Such a thick portion can be provided by providing the entire portion continuously.
The peripheral portion of adjacent, in the mounting direction side walls
Most thin and fluid-filled cylindrical mount, characterized in that the.