JP2003090375A - Cylindrical vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical vibration control device constituted by elastic ally connecting an inner shaft member and an outer cylinder member to each other with a main body elastic body capable of realizing withstand load perfor mance and durability of stopper rubber provided projected toward the inner shaft member from the outer cylinder member in a lightening hole formed through in the axial direction between the inner shaft member and the outer cylinder member while securing a soft initial spring characteristic and an effec tive linear characteristic. SOLUTION: Both sides in the axial direction of the stopper rubber 42 are constrained by a pair of constraining protruded parts 24, 24 fastened on the outer cylinder member 14, and a pair of head end protruded parts 46, 46 are integrally formed by projecting them on both sides in the peripheral direction rather than a central trough part 48 on a projected head end surface to the inside of the inner shaft member 12 of the stopper rubber 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical vibration damping device capable of exhibiting a vibration damping effect mainly against an input vibration in a direction perpendicular to an axis, and particularly to an automobile engine mount, body mount, differential mount, suspension bush and the like. The present invention relates to a cylindrical vibration damping device that is preferably used as

[0002]

BACKGROUND ART Conventionally, an inner shaft member and an outer cylinder member, which are spaced apart from each other in a radial direction, are elastically connected by a main body rubber elastic body as a kind of a cylindrical vibration isolator used as an engine mount as described above. In addition, by providing a pair of lightening holes extending axially through the space between the inner shaft member and the outer tubular member, on both sides sandwiching the inner shaft member in one direction perpendicular to the axis that is the main vibration input direction. There is known a structure in which the spring characteristics are adjusted and the generation of excessive tensile stress in the main rubber elastic body is avoided.

By the way, in such a cylindrical vibration isolator,
In order to realize a stopper mechanism that buffer-limits the relative displacement of the inner shaft member and the outer cylinder member when an excessive load is input, the stopper mechanism is located in the through hole and protrudes from the outer cylinder member toward the inner shaft member. A stopper rubber is preferably used. However, in such a stopper mechanism, the inner spring member is nonlinearly activated by setting the spring characteristic to be soft while setting the initial spring that is exerted under the condition that the input load is small. It is required to reliably limit the relative displacement of the outer cylinder member and the outer cylinder member.

Therefore, the applicant of the present invention has previously filed Japanese Patent Application Laid-Open No. 11-3
In Japanese Patent No. 36817, a pair of restraints that project from the outer tubular member toward the inner shaft member on both sides in the axial direction of the stopper rubber at a height smaller than that of the stopper rubber to restrain the base end portion of the stopper rubber from both sides in the axial direction. A cylindrical vibration damping device in which the convex portion is fixed to the outer cylindrical member has been proposed. By providing such a restraining convex portion, the entire rubber volume of the stopper rubber can be secured, the initial spring characteristics can be set low, and the elastic deformation amount of the stopper rubber is restricted when an excessive load is input. The non-linear spring characteristic can be advantageously realized.

However, as a result of further study and research by the present inventor, in the stopper rubber provided with the pair of restraining convex portions as described above, the central portion of the tip end surface of the stopper rubber in the protruding direction due to an excessive load input. It has become clear that there is a new problem that cracks are likely to occur in the part and that it is difficult to achieve a large load bearing performance.

[0006]

The present invention has been made in view of the above circumstances, and a problem to be solved by the present invention is that a pair of restraining convex portions are formed on both axial sides of a stopper rubber. In the stopper mechanism, the softness of the initial spring characteristics and the non-linear spring characteristics accompanying the increase in load can be sufficiently ensured, the stopper rubber can be prevented from being damaged when a large load is input, and excellent load bearing performance can be exhibited. It is to provide a cylindrical vibration damping device having a novel structure.

[0007]

Aspects of the present invention made to solve such problems will be described below. The constituent elements used in each of the following aspects can be used in any combination as much as possible. Further, the aspects and technical features of the present invention are not limited to those described below, but are described in the entire specification and the drawings, or the invention idea that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on this.

[0008] First, as a result of intensive investigations by the present inventor through experiments and analyzes in order to investigate the cause of damage to the stopper rubber in the above-described conventional cylindrical vibration isolator, as a result, the stopper rubber When the protruding tip portion is brought into contact with the inner member side, the stopper rubber having a Poisson's ratio of about 0.5 expands in the axial direction and the circumferential direction by the volume compressed and deformed in the height direction. Since both axial sides of the stopper rubber are composed of the pair of restraining convex portions, the stopper rubber is greatly deformed so as to escape to both sides in the circumferential direction, and as a result,
It is clear that the tensile stress pulling to both sides in the circumferential direction is concentrated on the central part of the stopper rubber, which may cause burst damage to the central part of the stopper rubber in the circumferential direction. Became.

The present invention has been made on the basis of the new knowledge obtained in this way, and the features of the first aspect of the present invention are that an inner shaft member and
The outer cylinder member spaced apart from the outer peripheral side of the inner shaft member is elastically coupled with the main body rubber elastic body interposed between the inner shaft member and the outer cylinder member facing surfaces in the direction perpendicular to the axis, and A pair of lightening holes extending axially through between the inner shaft member and the outer tubular member are provided on both sides of the inner shaft member in the direction perpendicular to the axis, and at least one of the pair of lightening holes is further provided. And a stopper rubber projecting from the outer tubular member toward the inner shaft member is formed so as to project from the outer rubber member toward the inner shaft member on both axial sides of the stopper rubber. In a cylindrical vibration-damping device having a pair of restraining projections that project at a small height to restrain the base end portion of the stopper rubber from both sides in the axial direction, the protruding tip surface of the stopper rubber is centered. A pair of tip projections are formed integrally with the stopper rubber so as to project on both sides in the circumferential direction, and the vertices of the pair of tip projections are projected on the inner shaft member when projected in the projection direction of the stopper rubber. The circumferential distance between the vertices is made smaller than the width dimension of the inner shaft member in the direction perpendicular to the axis so that they overlap.

In such a cylindrical vibration isolator according to this aspect, when the vibration load is input in the protruding direction of the stopper rubber and brought into contact with the protruding tip end inner shaft member side of the stopper rubber, the stopper rubber When a pair of tip projections projecting from the projecting tip surface of the stopper abut on the inner shaft member side, a compressive force is exerted on the circumferentially opposite side portions of the stopper rubber. Since the force acts on the central portion of the stopper rubber in the circumferential direction to reduce or eliminate the tensile stress,
The tensile force induced in the stopper rubber can be dispersed, the maximum value of the tensile stress can be reduced, and the load bearing performance of the stopper mechanism can be advantageously improved.

Moreover, in the tubular vibration-damping device according to this aspect, the entire volume of the stopper rubber is secured and the initial spring characteristics are set to be soft, while the pair of restraining protrusions expands the stopper rubber toward both sides in the axial direction. By limiting the output deformation, a non-linear spring characteristic with an increase in the input load can be advantageously exhibited.

Further, in the cylindrical vibration isolator according to this aspect, since the surface area of the stopper rubber is large, the surface stress associated with the increase of the input load can be reduced, and the occurrence of cracks can be prevented and the durability can be improved. Improvement is achieved.

In this aspect, the difference in the projecting height between the central portion of the projecting tip surface of the stopper rubber and the pair of projecting tip portions is appropriately determined according to the required stopper characteristics and the like. Is not limited. Further, the specific shape of the pair of tip convex portions is not particularly limited, but for example, it can be advantageously formed as a semi-cylindrical shape etc. as a whole that extends in the axial direction with a circular arc-shaped cross-sectional shape. Furthermore, the protruding tip portion of the stopper rubber including the pair of tip protrusions is desirably tapered as a whole, which can further reduce initial spring characteristics and further improve durability. .

A second aspect of the present invention is the tubular vibration-damping device according to the first aspect, wherein the pair of restraining convex portions are provided on a projecting tip end surface located opposite to the inner shaft member. , Forming a cushioning rubber layer respectively,
The protrusion height of the buffer rubber layer toward the inner shaft member is smaller than that of the central portion of the protruding tip surface of the stopper rubber. In this aspect of the invention, as the input load increases, the stopper rubber is brought into contact with the side of the inner shaft member and is elastically deformed by a predetermined amount, and then the cushion rubber is applied to the inner shaft member. You will be contacted. As a result, when the input load becomes large, the pressure receiving area of the stopper mechanism with which the inner shaft member abuts is the pressure receiving area of the buffer rubber added to the pressure receiving area of the stopper rubber. By realizing the stepwise nonlinear spring characteristic,
It is possible to more reliably and bufferably limit the relative displacement amount of the inner shaft member and the outer tubular member while ensuring a soft initial spring characteristic.

Furthermore, a third aspect of the present invention is, in the tubular vibration-damping device according to the first or second aspect, positioned between the pair of restraining convex portions to support the stopper rubber. It is characterized in that the inner peripheral surface of the outer tubular member has a substantially flat surface shape linearly extending in the circumferential direction with a predetermined width. In this aspect, the support surface of the stopper rubber of the outer tubular member can be advantageously formed, and the volume that can function as the stopper rubber can be advantageously secured in the circumferential direction.

A fourth aspect of the present invention is the tubular vibration damping device according to any one of the first to third aspects, wherein the outer peripheral surface of the inner shaft member has a cylindrical shape, and the inner shaft member has a cylindrical shape. The outer peripheral surface of the shaft member is covered with the main rubber elastic body over the entire circumference. In this aspect, since the stopper rubber is brought into contact with the main rubber elastic body that covers the inner shaft member, the spring characteristic of the main rubber elastic body can also be used for the stopper characteristic. Therefore, even if the rubber volume of the stopper rubber is small, the initial spring characteristic can be set softly. In particular, since the outer peripheral surface of the inner shaft member has a cylindrical shape, the thickness of the main rubber elastic body that covers the inner shaft member is even greater at the portion of the stopper rubber where the pair of tip projections abut. It can be advantageously secured.

Furthermore, a fifth aspect of the present invention is the tubular vibration damping device according to any one of the first to fourth aspects, wherein the axial dimension of the tip end portion of the stopper rubber is the outer tube. It is characterized in that the width is made smaller than the axially facing width dimension at the tip end portions of the pair of restraining convex portions provided on the member. In this aspect, the entire tip portion formed on the stopper rubber is positioned so as to project between the pair of restraining convex portions, and the effective dimension in the load input direction is set to be large for the entire tip portion. Therefore, the initial spring characteristic at the time of contact of the tip portion with the inner shaft member side can be set to be softer.

A sixth aspect of the present invention is the tubular vibration damping device according to any one of the first to fourth aspects, wherein the stopper rubber is substantially independent of the main rubber elastic body. It is characterized by being formed. In this embodiment, the presence of the stopper rubber and the elastic deformation of the stopper rubber can be prevented from affecting the main rubber elastic body, and the original vibration damping performance of the tubular vibration damping device can be stably exhibited. In addition,
The stopper rubber may be in any state in which the transmission of stress between the stopper rubber and the main rubber elastic body is avoided. For example, the stopper rubber is formed completely independently of the main rubber elastic body, and It is also possible to integrally vulcanize the main rubber elastic body and the stopper rubber with a structure in which they are connected to each other by a thin coating rubber layer that covers the peripheral surface.

Furthermore, a seventh aspect of the present invention is the tubular vibration damping device according to any one of the first to fifth aspects, wherein the stopper is provided only on one side of the pair of lightening holes. The rubber is formed so as to project, and the inner shaft member is eccentrically positioned on the side opposite to the stopper rubber in a direction perpendicular to the outer cylinder member, which is the direction perpendicular to the direction in which the stopper rubber projects. Elastic body is approximately V in the direction perpendicular to the axis
It is characterized in that the main rubber elastic body is constituted by a pair of elastic connecting leg portions each having a V-shaped cross section and extending from the inner shaft member on both sides in the circumferential direction sandwiching the stopper rubber. According to this aspect, since the inner shaft member is eccentrically positioned on the side opposite to the stopper rubber disposition direction with respect to the outer tubular member, the lightening hole for the stopper rubber disposition is provided. It becomes possible to secure the rubber volume of the stopper rubber more advantageously with a large cross section. Further, according to such an aspect, a tubular vibration damping device to which a static initial load is applied in a mounted state, such as an engine mount for an automobile,
It can be realized advantageously.

An eighth aspect of the present invention is the tubular vibration damping device according to any one of the first to seventh aspects, wherein the outer tubular member is made of synthetic resin, and the main body rubber elastic member is used. Body and the stopper rubber, by molding the outer tubular member with the surface of the main rubber elastic body as a part of the molding surface, the main rubber elastic body and the stopper rubber are formed simultaneously with the molding of the outer tubular member. Is assembled to the outer tubular member. In this aspect, the main rubber elastic body and the stopper rubber can be easily assembled to the outer tubular member, and in particular, the main body elastic body and the stopper rubber are fitted between the pair of restraining convex portions of the outer tubular member. In this state, the stopper rubber can be easily assembled. In the present aspect, preferably, a stopper rubber integrally formed with the main rubber elastic body is adopted, and the covering rubber layer that covers the inner peripheral surface of the outer tubular member over the entire circumference in the circumferential direction is The rubber elastic body and the stopper rubber are integrally formed.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings in order to more specifically clarify the present invention.

First, FIGS. 1 to 3 show an automobile engine mount 10 which is a cylindrical vibration damping device according to an embodiment of the present invention. This engine mount 10
An inner cylinder member 12 as an inner shaft member, and the inner cylinder member 12
An outer cylinder member 14 as an outer cylinder member, which is spaced apart from the outer peripheral side of, is elastically connected by a main rubber elastic body 16, and is interposed between a body and a power unit of an automobile (not shown). As a result, the inner and outer tubular members 12, 1 are mainly arranged in the direction perpendicular to the axis which is the vertical direction in FIG.
It is possible to exert an effective anti-vibration effect against the vibration exerted between the four. In the following description, the vertical direction means the vertical direction in FIG. 1 in principle.

More specifically, the inner cylinder member 12 is formed of a metal tube and has a straight, thick-walled cylindrical shape. Further, in the outer peripheral area of the inner tubular member 12,
The outer cylinder member 14 is arranged so as to be spaced radially outward.
The outer cylinder member 14 is formed of, for example, a synthetic resin material such as a fiber-reinforced polyamide resin, and has a substantially cylindrical body shape having a substantially constant width and extending over the entire circumference in the circumferential direction. The unit 18 is provided.

In the present embodiment, the main body tubular portion 1
8 has a flat bottom portion 20, and the inner peripheral surface of the bottom portion 20 serves as a stopper support surface 22 that extends substantially orthogonal to the main vibration input direction. In addition, the main body tubular portion 18
Has substantially symmetric shapes on the left and right sides with respect to one radial line extending in the vertical direction in FIG. 1, which is the main vibration input direction.

A pair of restraining projections 24, 24 projecting on the inner peripheral surface toward the inner tubular member 12 are integrally formed in the main body tubular portion 18 at both axial sides of the bottom portion 22, respectively. A recess 26 having a predetermined width and linearly extending in the circumferential direction is formed on the bottom portion 22 between the facing surfaces of the pair of restraining convex portions 24. The constraining protrusions 24, 24 are integrally formed only in the circumferential central portion of the bottom portion 22 with a predetermined circumferential length, and both circumferential ends of the recess 26 are open on both sides in the axial direction on the bottom portion 22. Has been done. In addition, each restraint convex portion 24 has a substantially constant height over the entire length in the circumferential direction, and the protruding tip surface 23 thereof has a flat surface shape extending in the circumferential direction with a predetermined axial width. Furthermore, the axially opposed surfaces of both the restraining convex portions 24, 24 gradually expand toward the inner cylindrical member 12 side, and the distance between the facing surfaces gradually increases toward the protruding tip side of the restraining convex portions 24, 24. The inclined surface 25 is

Furthermore, the outer cylinder member 14 includes a main body cylinder portion 1
8, a pair of mounting leg portions 28, 28 that extend obliquely downward from both axial end surfaces of the bottom portion 20 and expand outward in the axial direction are integrally formed. The mounting leg portions 28, 28 are respectively provided with bolts. A metal sleeve 30 for insertion is assembled in a through state in the thickness direction.

The inner cylinder member 12 is inserted into the hollow inside of the main body cylinder portion 18 with respect to the outer cylinder member 14 as described above, and is upwardly moved by a predetermined amount with respect to the central axis of the main body cylinder portion 18. It is eccentrically located.

Thus, the inner cylinder member 12 and the outer cylinder member 1
A main body rubber elastic body 16 is interposed between the four (main body tubular portion 18), and the main body rubber elastic body 16 elastically connects the inner tubular member 12 and the outer tubular member 14. The main rubber elastic body 16 as a whole extends in the axial direction with a reverse V-shaped cross-sectional shape as a whole, and the inner cylindrical member 12 is disposed so as to penetrate through the central bent portion of the V-shape. The body 16 is vulcanized and adhered to the outer peripheral surface of the inner tubular member 12, while both V-shaped tip portions are fixed to the inner peripheral surface of the main body tubular portion 18 of the outer tubular member 14. The inner cylinder member 1
The axially intermediate portion of 2 is embedded in the main rubber elastic body 16, and the outer peripheral surface of the inner tubular member 12 is covered with the main rubber elastic body 16 over the entire circumference.

In other words, the main rubber elastic body 16 is composed of a pair of elastic connecting leg portions 32, 32 extending from the inner tubular member 12 toward the outer tubular member 14, respectively, and particularly this embodiment. Then, the pair of elastic connection leg portions 32, 32 are arranged so that the inner tubular member 12 is attached to the outer tubular member 14.
Is formed so as to extend obliquely downward at a predetermined center angle that expands toward the side opposite to the eccentric direction (downward in FIG. 1), and extends vertically through the central axis of the inner tubular member 12. The left and right sides are substantially line-symmetrical with one radial line as the axis of symmetry. In addition, each of the elastic connection leg portions 32, 32
In that case, the wall thickness around the central axis of the inner tubular metal fitting 12 is
The diameter is gradually reduced from the inner cylinder member 12 to the outer cylinder member 14.

On the other hand, on the inner peripheral surface of the main body tubular portion 18 of the outer tubular member 14, the inner peripheral surface of the main body tubular portion 18 extends continuously over the entire circumference in a substantially constant thickness dimension. A covering rubber layer 34 covering substantially the entire surface is formed and fixed, and to the covering rubber layer 34, the outer end portions of the elastic connecting legs 32, 32 constituting the main rubber elastic body 16 are formed. Are integrally connected. In short, the main rubber elastic body 16 is integrally formed with the covering rubber layer 34.

As a result, the inner cylinder member 12 and the outer cylinder member 14 are
An upper side lightening hole 36 and a lower side lightening hole 38 that extend axially therethrough are provided on both upper and lower sides of the main rubber elastic body 16 between them. A rebound stopper 40 that projects upward from the inner tubular member 12 toward the outer tubular member 14 is disposed in the upper lightening hole 36. This rebound stopper 40 has a rubber elastic body 1
6 is integrally formed with the inner cylindrical member 12, and is formed in a central portion of the inner tubular member 12 in the axial direction so as to extend in a predetermined length in the axial direction in a substantially chevron section.

On the other hand, a bound stopper 42 as a stopper rubber is provided in the lower lightening hole 38 so as to project upward from the outer tubular member 14 toward the inner tubular member 12. In addition, the bound stopper 42 is used for the outer cylinder member 14
Rubber layer 3 for covering the inner peripheral surface of the main body tubular portion 18 in
It is integrally molded with the No.4. In short, in this embodiment,
The main rubber elastic body 16 described above is formed as an integrally vulcanized molded product including the covering rubber layer 34, the rebound stopper 40, and the bound stopper 42. The covering rubber layer 34 for covering the inner peripheral surface of the main body tubular portion 18 extends to the protruding tip surfaces 23, 23 of the pair of restraining convex portions 24, 24 projectingly provided on the main body tubular portion 18, As a result, a cushioning rubber layer 44 is formed on the protruding tip surfaces 23, 23 of the restraint convex portions 24, 24 so as to spread in a substantially integral thickness dimension.

The bound stopper 42 has a circumferential length slightly shorter than that of the stopper support surface 22 at the circumferential center portion of the stopper support surface 22 formed on the bottom portion 20 of the main body tubular portion 18. . In addition, the protruding height of the bound stopper 42 is the same as that of the restraint protrusion 2 provided on the bottom portion 20.
It is set to be larger than the protruding height of 4, 24. As a result, the base end portion of the bound stopper 42 is positioned in a state of being embedded in the recess 26 between the restraint convex portions 24, 24, and the bottom surface of the recess 26 (stopper support surface 22) and the restraint convex portion. While being fixed to the inclined surfaces 25, 25 of 24, 24, the tip portion of the bound stopper 42 projects from the recess 26 between the restraining projections 24, 24 into the lower lightening hole 38 to form an inner cylinder. It extends toward the member 12. As is clear from FIG. 2, the bound stopper 42
Is projected in the lower lightening hole 38 with an axial dimension smaller than the distance between the facing surfaces at the upper end openings of the pair of restraining convex portions 24, 24.

Further, in the bound stopper 42,
The outer peripheral surface of the portion projecting from the recess 26 between the restraint convex portions 24, 24 is inclined in the axial direction and the circumferential direction so as to be tapered toward the projecting tip side in the axial direction and the circumferential direction. ing. Further, the protruding tip end surface of the bound stopper 42 has the same dimension as or slightly smaller than the bottom surface of the recess 26 in the axial direction, and also has the dimension slightly smaller than the restraining convex portions 24, 24 in the circumferential direction. The main rubber elastic body 16 is positioned to face the embedded portion of the inner tubular member 12 at a predetermined distance in the vertical direction.

Further, on the projecting tip surface of the bound stopper 42, a pair of tip projecting portions 46 having a generally kamaboko shape, which extend in the axial direction with a substantially arcuate shape and a constant cross-sectional shape at both end portions in the circumferential direction, are provided. 46 is integrally formed. The central portion in the circumferential direction of the projecting tip surface of the bound stopper 42 is positioned between the pair of tip projecting portions 46, 46, so that the valley-shaped central valley portion 4 is formed.
The projection height of the tip projections 46, 46 formed on both sides in the circumferential direction is larger than the projection height of the central valley portion 48.

It should be noted that each of the projecting vertices of the tip projections 46, 46 is, as shown in FIG. 1, all of the inner cylindrical member 1 when projected in the vertical direction which is the main vibration input direction.
Positioned so as to overlap 2. Further, the central valley portion 48 is set at a position which is protruded toward the inner tubular member 12 side by a predetermined amount from the surface of the cushioning rubber layer 44 formed on the restraining convex portions 24, 24 of the outer tubular member 14. .

By the way, in the engine mount 10 having the above-described structure, the integrally vulcanized molded product of the main rubber elastic body 16 vulcanized and bonded to the inner tubular member 12 and the outer tubular member 1 are provided.
4 and 4 are separately formed, and then the outer cylinder member 14
It is also possible to assemble the main body rubber elastic body 16 and to perform adhesion or the like, but it is preferable that, for example, (a) the inner cylindrical member 12 that is separately manufactured is formed in the molding cavity of the vulcanization mold of the main body rubber elastic body 16. With the outer cylinder member 14 positioned and set, the molding cavity is filled with a predetermined rubber material to vulcanize the main rubber elastic body 16, and at the same time, the inner and outer cylinder members 12 and 14 are assembled and vulcanized and bonded. (B) Positioning set of integrally vulcanized molded product of the main rubber elastic body 16 which is vulcanized in advance and vulcanized and adhered to the inner cylindrical member 12 in the molding cavity of the resin molding die of the outer cylindrical member 14. A method is used in which a predetermined resin material is filled in the molding cavity in the squeezed state, and the main body rubber elastic body 16 is bonded and assembled to the outer cylinder member 14 at the same time when the outer cylinder member 14 is molded. In particular, according to the latter manufacturing method (b), it is possible to reduce or eliminate the occurrence of tensile stress due to vulcanization shrinkage of the main rubber elastic body 16 and improve durability.

Although not clearly shown in the drawing, the engine mount 10 having the above-described structure has a structure in which the mounting legs 28, 28 of the outer tubular member 14 are bolted to the metal sleeve 30 so that the automobile is mounted. While being fixed to the body of the vehicle, the inner cylinder member 12 is fixed to the power unit of the automobile by the rod inserted through the center hole thereof, so that the inner cylinder member 12 is mounted between the power unit of the automobile and the body. The power unit is designed to support the body against vibration. In addition, in such a mounted state, between the inner and outer cylindrical members 12 and 14,
When the static shared supporting load of the power unit is exerted in the vertical direction, the main rubber elastic body 16 is elastically deformed by a predetermined amount, and the inner and outer tubular members 12, 14 are positioned substantially coaxially.

Further, in such a mounted state, the bound stopper 42 and the rebound stopper 40, and the main rubber elastic body 16 and the outer cylinder on the inner cylindrical member 12 which is vertically opposed to the protruding tip surfaces thereof. Member 14
A predetermined amount of gap is provided between the upper covering rubber layers 34. Then, when a large vibration load is input during traveling of the vehicle and the inner and outer cylindrical members 12, 14 are relatively displaced in the vertical direction due to elastic deformation of the main rubber elastic body 16, the bound stopper 4
2 is brought into contact with the main rubber elastic body 16 on the inner tubular member 12, or the rebound stopper 40 is brought into contact with the covering rubber layer 34 on the outer tubular member 14, so that the inner and outer tubular members 12, 14 The relative displacement amounts in the bounding direction and the rebounding direction are limited in a buffer manner.

Here, the bound stopper 42 is
Since both sides in the axial direction are constrained by the pair of constraining convex portions 24, 24, the protruding height of the outer cylinder member 14 from the stopper supporting surface 22 is suppressed while suppressing an excessive elastic deformation amount and strain when a large load is input. Since the size can be set large, the spring characteristic at the initial stage of contact of the bound stopper 42 with the inner cylinder member 12 side can be set sufficiently soft, and the spring characteristic is exhibited when a large vibration load is input. It is possible to reliably and stably limit the relative displacement amount of the inner and outer tubular members 12 and 14 by setting a large spring rigidity, which is a non-linear load-deflection characteristic, that is, a non-linear characteristic. The spring characteristics can be advantageously realized, and a stopper mechanism that can exert an effective displacement amount limiting effect without a shock feeling and a hitting sound can be realized.

In addition, in the bound stopper 42, the inner cylindrical member 12 is separated from the inner cylindrical member 12 on both sides in the circumferential direction with respect to the central valley portion 48 opposed to the inner cylindrical member 12 on the input central axis of the main vibration. The front end protrusions 46, 46 that are positioned opposite to each other are protruded largely toward the inner tubular member 12 side, and at the time of vibration input, the front end protrusions 46, 46 are more than the central valley portion 48. Is the main rubber elastic body 1 on the inner cylinder member 12 side with a smaller input load.
6 will be abutted. Therefore, by compressing and deforming the both end protrusions 46, 46,
An effective compressive force is generated in the bound stoppers 42 on both sides in the circumferential direction, and this compressive force is also exerted on the central portion of the bound stoppers 42 in the circumferential direction as a compressive force.

Therefore, even when the bound stopper 42 is largely compressed and deformed, the stress generated in the bound stopper 42 is easily dispersed as a whole, and the bound stopper 42 is concentrated in the central portion in the circumferential direction. The tensile stress applied to both sides in the circumferential direction can be reduced or eliminated, and as a result, the load bearing strength and durability of the bound stopper 42 can be advantageously improved.

Moreover, since the protruding vertices of the pair of tip projections 46, 46 of the bound stopper 42 are formed so as to overlap the inner cylindrical member 12 in the load input direction, the tip projections 46, 46 are formed. Since a compressive load can be efficiently exerted on the bound stopper 42 through 46, the tip projections 46, 46 are prevented from falling down in the circumferential direction, and the tip projections 46, 46 are compressed and deformed. Based on the above, the effect of reducing the tensile stress in the central valley portion 48 as described above can be more effectively exhibited.

In addition, the bound stopper 42 is formed by the pair of tip projections 46, 46 and the central valley 48.
Since the contact surface to the side is made uneven and has a corrugated surface and the surface area is increased, the surface stress of the bound stopper 42 generated due to the contact to the side of the inner cylinder member 12 is reduced. As a result, the occurrence of cracks in the bound stopper 42 and the improvement in durability can be achieved more effectively.

Further, in this embodiment, since the outer peripheral surface of the inner cylinder member 12 is formed into a cylindrical shape, it is formed by the main rubber elastic body 16 covering the inner cylinder member 12, and the tip end protrusion of the bound stopper 42 is formed. The rubber thickness at the contacted portion on the side of the inner tubular member 12 where the portions 46, 46 are brought into contact can be advantageously ensured, whereby the initial spring characteristic at the time of contact of the bound stopper 42 can be improved. It is possible to set a softer value without increasing the protruding height of the.

Further, in the present embodiment, when a large vibration load is input, the inner cylinder member 12 side first contacts the tip convex portions 46, 46 of the bound stopper 42, and then the central valley portion 48 is crushed. , The contact of the bound stopper 42 over substantially the front end of the projecting tip surface, and then the cushioning rubber layer 4
It is adapted to be brought into contact with the restraining convex portions 24, 24 via 4, 44, whereby it becomes soft initially and becomes non-linearly hard as the input load increases, and finally becomes the inner and outer cylinders. A desired stopper mechanism that can reliably regulate the relative displacement amount of the members 12 and 14 can be realized more advantageously.

The embodiments of the present invention have been described in detail above, but these are merely examples, and the present invention should not be construed as being limited to the specific description of the embodiments. .

For example, in the above embodiment, only the stopper mechanism in the bounding direction was made of the stopper rubber according to the present invention. However, in addition to the stopper mechanism in the bounding direction or in place of the stopper mechanism in the bounding direction,
It is of course also possible to construct the stopper mechanism in the rebound direction from the stopper rubber according to the invention.

Further, in the above embodiment, the constraining convex portions 24,
24 is a bottom portion 20 of the main body tubular portion 18 of the outer tubular member 14.
Although it is formed with a predetermined length only in the central portion of the above, the circumferential length and the protruding height of the restraint convex portions 24, 24 are appropriately changed according to the required characteristics of the stopper mechanism. But it's not limited. Specifically, for example, as shown in FIGS. 4 to 5, the restraint convex portions 24, 24 are formed over the entire length of the bottom portion of the main body tubular portion 18, and the base end portion of the bound stopper 42 is substantially circumferentially formed. It is also possible to employ a configuration in which the binding is restrained all over, and with such a configuration, it is possible to further increase the rise of spring characteristics by the bound stopper 42 and to further improve durability. In addition, in FIGS. 4 to 5, in order to facilitate the understanding thereof, the same reference numerals as those in the above-described embodiment are respectively attached to the members and parts having the same structures as those in the above-described embodiment in the drawings. I'll do it. Further, the vertical cross-sectional views of the engine mount shown in FIGS. 4 to 5 are substantially the same as the vertical cross-sectional views of the above-described embodiment, and therefore the illustration thereof is omitted.

Further, in the above-mentioned embodiment, the main rubber elastic body 16 which has a substantially V-shaped cross section and extends in the axial direction is adopted, but the specific shape of the main rubber elastic body depends on the required vibration damping characteristics and It is appropriately determined in consideration of load bearing performance and the like, and is not limited. Specifically, for example, the inner and outer tubular members 12, 14 are arranged on the same central axis, and the inner and outer tubular members 12, 14 are opposed to each other on both sides sandwiching the inner tubular member 12 in one diametrical direction. It is also possible to adopt a main body rubber elastic body having a linearly extending cross-sectional shape, and such a main body rubber elastic body is a static initial load exerted under the mounted state such as a suspension bush or an engine roll mount. Can be advantageously employed when is very small or near zero.

Further, in the above-mentioned embodiment, the inner cylindrical member made of metal and the outer cylindrical member made of synthetic resin are adopted, but the material of the inner and outer cylindrical members is not limited, and the required strength, characteristics and use conditions are required. It can be appropriately selected in consideration of the above.

Further, the mounting leg portion 2 of the outer cylinder member 14
8 and 28 are not always necessary, and for example, an outer cylinder member having a cylindrical outer peripheral surface may be adopted, and the outer cylinder member may be press-fitted and mounted in a mounting hole such as an arm eye in a vehicle suspension mechanism or the like. It is possible.

Furthermore, in the above-described embodiment, the pair of restraining convex portions 24, 24 are integrally formed with the main body tubular portion 18 of the outer tubular member 14, but these restraining members are formed separately from the outer tubular member 14. It can also be formed by being fixed to the main body tubular portion 18 afterward.

In addition, in the above embodiment, a specific example of the present invention applied to an engine mount for an automobile is shown. However, the present invention is applicable to a body mount, a differential mount, a suspension bush for an automobile, or an automobile. Any of them can be applied to the cylindrical vibration isolator used in various devices other than the above.

Although not listed one by one, the present invention
The present invention can be carried out in a mode in which various changes, modifications, improvements, etc. are added based on the knowledge of a person skilled in the art, and such a mode does not depart from the gist of the present invention.
Both are included within the scope of the present invention,
Needless to say.

[0056]

As is apparent from the above description, in the tubular vibration damping device having the structure according to the present invention, when a large load is input and the stopper rubber is brought into contact with the inner shaft member side. , The pair of tip projections projecting on both sides of the stopper rubber in the circumferential direction are brought into contact with the inner shaft member, and an effective compression force is exerted on both sides of the stopper rubber in the circumferential direction. By acting to reduce the tensile force generated in the circumferential intermediate portion of the stopper rubber, the burst damage in the circumferential intermediate portion of the stopper rubber can be effectively reduced or avoided. As a result, excellent load bearing performance and durability can be realized in the stopper rubber, and thus in the vibration damping device.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a left side view of FIG.

FIG. 4 is a left side view corresponding to FIG. 3, showing an engine mount as another embodiment of the present invention.

5 shows the engine mount shown in FIG. 4, FIG.
It is a cross-sectional view corresponding to.

[Explanation of symbols]

10 engine mount 12 Inner tube member 14 Outer cylinder member 16 Rubber elastic body 18 Body tube 22 Stopper support surface 24 Restraint convex part 26 recess 32 Elastic connection leg 34 Coated rubber layer 36 Upper hole 38 Lower hole 40 rebound stopper 42 Bound stopper 44 cushioning rubber layer 46 Tip protrusion 48 Central Valley

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsutomu Tamura             1-4-1 Chuo Stock Market, Wako City, Saitama Prefecture             Inside Honda Research Laboratory (72) Inventor Masuhiro Ogawa             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business F-term (reference) 3D001 AA17 AA19 DA12                 3D035 CA05 CA06                 3J048 AA01 BA19 CB05 EA01 EA15                       EA36                 3J059 AB12 BA42 DA13 GA02 GA09

Claims (8)

[Claims] 1. A main body rubber in which an inner shaft member and an outer cylinder member spaced apart from the outer peripheral side of the inner shaft member are interposed between surfaces of the inner shaft member and the outer cylinder member which face each other in the direction perpendicular to the axis. While being elastically connected by an elastic body, a pair of lightening holes extending axially through between the inner shaft member and the outer cylinder member are provided on both sides in the axis-perpendicular direction sandwiching the inner shaft member, Further, at least one of the pair of lightening holes is positioned to form a stopper rubber projecting from the outer tubular member toward the inner shaft member, and
A pair of constraining projections projecting from the outer tubular member toward the inner shaft member at a height smaller than that of the stopper rubber on both axial sides of the stopper rubber to constrain the base end portion of the stopper rubber from both axial sides. In a cylindrical vibration isolator provided with a portion, a pair of tip projections are integrally formed on the stopper rubber by projecting the projecting tip surfaces of the stopper rubber on both sides in the circumferential direction with respect to the central portion. The circumferential separation distance between the vertices is made smaller than the width dimension in the axis-perpendicular direction of the inner shaft member so that each of the vertices of the inner rubber member overlaps the inner shaft member in the projection of the stopper rubber in the projection direction. A characteristic cylindrical vibration damping device. 2. A cushioning rubber layer is formed on each of the pair of restraining protrusions on the projecting front end faces located opposite to the inner shaft member, and the cushioning rubber layer is formed on the inner shaft member side. The tubular vibration damping device according to claim 1, wherein the protruding height is smaller than the central portion of the protruding tip surface of the stopper rubber. 3. The inner peripheral surface of the outer tubular member, which is positioned between the pair of restraining convex portions and supports the stopper rubber, has a substantially flat surface shape linearly extending in the circumferential direction with a predetermined width. The tubular vibration damping device according to claim 1. 4. The outer peripheral surface of the inner shaft member has a cylindrical shape, and the outer peripheral surface of the inner shaft member is covered over the entire circumference by the main rubber elastic body. The cylindrical vibration isolator according to any one of 1. 5. The axial dimension of the tip end portion of the stopper rubber is smaller than the axially facing width dimension of the tip end portions of the pair of restraining protrusions provided on the outer tubular member. The tubular vibration isolator according to any one of claims. 6. The stopper rubber is formed substantially independently of the main rubber elastic body.
The cylindrical vibration isolator according to any one of 1. 7. A direction perpendicular to an axis in which the stopper rubber is formed to project only on one side of the pair of lightening holes, and the inner shaft member is a protruding direction of the stopper rubber with respect to the outer tubular member. Is eccentrically positioned on the side opposite to the stopper rubber, and the main rubber elastic body has a substantially V-shaped cross-section in the direction perpendicular to the axis, and is disposed on both sides in the circumferential direction sandwiching the stopper rubber from the inner shaft member. The tubular vibration-damping device according to any one of claims 1 to 6, wherein the main rubber elastic body is constituted by a pair of elastic connecting leg portions that respectively extend. 8. The outer tubular member is formed of a synthetic resin material, and in the presence of the main rubber elastic body and the stopper rubber, the surface of the main rubber elastic body is used as a part of a molding surface to form the outer tubular member. By being molded,
8. The tubular vibration damping device according to claim 1, wherein the main body rubber elastic body and the stopper rubber are assembled to the outer tubular member at the same time when the outer tubular member is molded.