JP2021017969A - Tubular vibration isolation device - Google Patents

Abstract

To provide a tubular vibration isolation device having a novel structure which can achieve a degree of freedom of the tuning of a spring characteristic or the like while sufficiently securing the durability of a main body rubber elastic body.SOLUTION: In a tubular vibration isolation device 10 in which an inner shaft member 12 and an outer cylinder member 14 are connected to each other via a main body rubber elastic body 16, a hollow part 24 opened at an end face in an axial direction, and extending in the axial direction toward a plate-shaped part 18 of the inner shaft member 12 on an external peripheral face of the inner shaft member 12 is formed at the main body rubber elastic body 16. A deformation control face 34 protruding on the external peripheral face is formed at the inner shaft member 12. An overlapped region 36 expanding along an inner face 26 of the hollow part 24, and a release region 38 gradually separating from the inner face 26 of the hollow part 24 toward an opening side of the hollow part 24 from the overlapped region 36 are arranged at the deformation control face 34. An abutment region of the main body rubber elastic body 16 abutting on the deformation control face 34 is expanded toward the release region 38 from the overlapped region 36 following an increase of an input load.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tubular anti-vibration device applied to, for example, an engine mount of an automobile.

Conventionally, tubular vibration isolators applied to automobile engine mounts, subframe mounts, and the like have been known. For example, in Japanese Patent Application Laid-Open No. 2018-071768 (Patent Document 1), an inner shaft member having a plate-shaped portion at the upper end and an outer cylinder member having an expanded portion at the upper end are elastically connected by a rubber elastic body of the main body. An engine mount having the above-mentioned structure is disclosed.

Japanese Unexamined Patent Publication No. 2018-071768

By the way, in the tubular vibration isolator having a conventional structure, a hole may be provided in the rubber elastic body of the main body for the purpose of adjusting the spring characteristics and the like. For example, as described in Patent Document 1 and the like, a concave hole having an opening on one end surface of the main body rubber elastic body in the axial direction and extending in the circumferential direction is adopted.

However, it may be difficult to ensure durability when the pits as in Patent Document 1 are provided. For example, when the input load is large, or when it is difficult to secure the radial thickness of the rubber elastic body of the main body due to the size set in consideration of the arrangement space of the tubular vibration isolator, etc. In some cases, it was difficult to achieve both the realization of spring characteristics by holes and the assurance of durability at a high level.

An object of the present invention is to provide a tubular vibration isolator having a novel structure capable of achieving tuning flexibility such as spring characteristics while sufficiently ensuring the durability of the rubber elastic body of the main body.

Hereinafter, preferred embodiments for grasping the present invention will be described, but each of the embodiments described below is described as an example, and not only can be appropriately combined with each other and adopted, but also described in each embodiment. The plurality of components of the above can be recognized and adopted independently as much as possible, and can be appropriately adopted in combination with any of the components described in another embodiment. Thereby, in the present invention, various other aspects can be realized without being limited to the aspects described below.

The first aspect is a tubular type in which an inner shaft member having a plate-shaped portion at one end in the axial direction and an outer tubular member having a spread-shaped portion at one end in the axial direction are connected by a main body rubber elastic body. In the vibration isolator, the rubber elastic body of the main body is provided with a cavity portion that opens at the other end face in the axial direction and extends axially toward the plate-shaped portion on the outer peripheral surface of the inner shaft member. The inner shaft member is provided with a deformation control surface protruding on the outer peripheral surface, and the deformation control surface has an overlapping region extending along the inner surface of the cavity portion and the cavity from the overlapping region. A release region that gradually separates from the inner surface of the cavity toward the opening side of the portion is provided, and the contact region of the main body rubber elastic body with the deformation control surface overlaps with the increase in the input load. It extends from the region toward the release region.

According to the tubular anti-vibration device having a structure according to this embodiment, the size and position of the free surface of the main body rubber elastic body and the rubber volume of the main body rubber elastic body are provided by providing the hollow portion in the main body rubber elastic body. It is possible to adjust the spring characteristics and the like by appropriately setting the above according to the cavity, and an excellent degree of freedom in tuning can be ensured.

A deformation control surface that protrudes on the outer peripheral surface of the inner shaft member is provided, and when the elastic deformation of the main body rubber elastic body occurs, the inner surface of the hollow portion of the main body rubber elastic body comes into contact with the deformation control surface, so that the cavity portion The deformation mode or the amount of deformation of the inner surface can be controlled. Therefore, it is possible to suppress a deformation mode in which strain is locally concentrated on the inner surface of the cavity, and for example, stress and strain at the bottom of a hole, which is likely to be a problem in a recessed hole of a conventional structure. Concentration can be avoided and the durability of the rubber elastic body of the main body can be improved.

The deformation control surface provided on the inner shaft member has an overlapping region and a release region, and when the main body rubber elastic body is elastically deformed and the cavity is deformed, the main body rubber elastic body hits the deformation control surface. The tangent region expands from the overlapping region to the release region as the input load and the amount of elastic deformation increase. As a result, when the amount of deformation of the main body rubber elastic body is small, the restraint area of the main body rubber elastic body by the deformation control surface is narrowed, and the large free surface of the main body rubber elastic body realizes a soft spring characteristic with a small spring constant. can do. As the amount of deformation of the main body rubber elastic body increases, the contact region of the main body rubber elastic body with respect to the deformation control surface expands to the release region, and the restraint region of the main body rubber elastic body by the deformation control surface widens, for example, the main body. It is also possible to improve the deformation rigidity of the rubber elastic body non-linearly.

In the second aspect, in the tubular anti-vibration device described in the first aspect, the deformation control surface is a curved surface in which a plurality of stages having stepwisely different protrusion heights are smoothly connected in the axial direction. It is what has been done.

According to the tubular anti-vibration device having a structure according to this embodiment, the contact area of the main body rubber elastic body with the deformation control surface gradually increases as the input load increases, so that the main body rubber elastic body The soft spring characteristics when the amount of deformation is small and the dispersion of strain when the amount of deformation of the rubber elastic body of the main body is large are effectively realized.

The third aspect is the tubular vibration isolator described in the first or second aspect, wherein the deformation control surface is formed of a large diameter portion integrally formed with the inner shaft member.

According to the tubular vibration isolator having a structure according to this aspect, the inner shaft member provided with the deformation control surface is realized by a simple structure having a small number of parts.

The fourth aspect is the tubular anti-vibration device according to the first or second aspect, wherein the deformation control surface is formed by another member that is externally fitted and fixed to the inner shaft member.

According to the tubular anti-vibration device having a structure according to this aspect, for example, it is possible to provide a deformation control surface by retrofitting a separate member to the inner shaft member that has been vulcanized and adhered during molding of the rubber elastic body of the main body. become.

A fifth aspect is the depth of the cavity in the tubular vibration isolator described in any one of the first to fourth aspects, in which the stopper protrusion protruding from the inner shaft member into the cavity is the depth of the cavity. It is provided in the middle part of the direction.

According to the tubular anti-vibration device having a structure according to this embodiment, it is possible to realize a stopper mechanism that bufferably limits the relative displacement amount of the inner shaft member and the outer cylinder member in the direction perpendicular to the axis by using the cavity. Can be done.

Moreover, since the stopper protrusion abuts on the inner surface of the cavity, the deformation is restrained even when the inner surface of the cavity deviates from the deformation control surface, so that the rubber elastic body of the main body is distorted when a large load is input. By suppressing the amount, the durability of the rubber elastic body of the main body is further improved.

In the sixth aspect, in the tubular anti-vibration device according to any one of the first to fifth aspects, the outer peripheral surface of the main body rubber elastic body located on the outer peripheral side of the overlapping region is the outer cylinder. It is a free surface that is not fixed to the member.

According to the tubular anti-vibration device having a structure according to this embodiment, the outer peripheral surface of the main body rubber elastic body located on the outer peripheral side of the overlapping region is a free surface, so that the degree of freedom of deformation of the main body rubber elastic body is increased. In addition to being secured and alleviating stress concentration, it is also easy to avoid a significant increase in spring even in a state where the inner surface of the cavity portion of the main body rubber elastic body is overlapped and the deformation is restrained by the overlapping region.

A seventh aspect is the tubular anti-vibration device according to any one of the first to sixth aspects, wherein the deformation control surface is continuous over the entire circumference in the circumferential direction, and the deformation control surface is described. The overlapping region extends along the inner surface of the cavity over the entire circumference.

According to the tubular anti-vibration device having a structure according to this aspect, the concentration of local strain of the main body rubber elastic body with respect to the input is avoided over the entire circumference, and the durability of the main body rubber elastic body can be improved.

The eighth aspect is the tubular anti-vibration device according to any one of the first to seventh aspects, wherein the cavity portion extends in the axial direction with a substantially constant inner diameter.

According to the tubular anti-vibration device having a structure according to this embodiment, when the elastic body rubber is elastically deformed, strain is unlikely to be concentrated on the inner surface of the cavity.

According to the present invention, in a tubular anti-vibration device, it is possible to achieve a degree of freedom in tuning such as spring characteristics while sufficiently ensuring the durability of the rubber elastic body of the main body.

Sectional drawing which shows the engine mount as the 1st Embodiment of this invention. Cross-sectional view of the integrally vulcanized molded product constituting the engine mount shown in FIG. A cross-sectional view showing a state in which an axial compressive load is applied to the rubber elastic body of the main body of the engine mount shown in FIG. Sectional drawing which shows the engine mount as the 2nd Embodiment of this invention. Cross-sectional view of the integrally vulcanized molded product constituting the engine mount shown in FIG. A cross-sectional view showing a state in which an axial compressive load is applied to the rubber elastic body of the main body of the engine mount shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an engine mount 10 for an automobile as a first embodiment of a tubular vibration isolator having a structure according to the present invention. The engine mount 10 has a structure in which the inner shaft member 12 and the outer cylinder member 14 are connected by a main body rubber elastic body 16. In the following description, the vertical direction means the vertical direction in FIG. 1 which is the direction of the central axis of the mount.

The inner shaft member 12 is made of metal, synthetic resin, or the like. The inner shaft member 12 has a structure in which a ring plate-shaped plate-shaped portion 18 is superposed on the upper surface of a substantially cylindrical shaft body 20 extending linearly in the vertical direction.

The outer cylinder member 14 is made of metal, synthetic resin, or the like, like the inner shaft member 12. The outer cylinder member 14 has a thin-walled large-diameter substantially cylindrical shape. The outer cylinder member 14 is provided with an expanded portion 22 having a substantially constant diameter and having a large diameter upward above the tubular portion 21 extending linearly in the vertical direction. Further, on the lower side of the tubular portion 21, an inner flange-shaped portion 23 projecting toward the inner peripheral side is provided.

The plate-shaped portion 18 provided at the upper end portion of the inner shaft member 12 and the outer cylinder member 14 are arranged vertically apart from each other and are elastically connected by the main body rubber elastic body 16. The main body rubber elastic body 16 has a cylindrical shape and has a hollow portion 24 at a central portion in the radial direction. The inner surface 26 of the cavity 24 extends linearly in the vertical direction with a substantially constant inner diameter, and has an opening 28 on the lower surface of the main body rubber elastic body 16. In the hollow portion 24, the opening 28 at the lower end of the inner surface 26 is widened downward, and the upper end portion has a partially small diameter. The upper surface of the main body rubber elastic body 16 is fixed to the lower surface of the plate-shaped portion 18 of the inner shaft member 12, and the outer peripheral surface of the main body rubber elastic body 16 is fixed to the inner peripheral surface of the outer cylinder member 14. .. As shown in FIG. 2, the main body rubber elastic body 16 is formed as an integrally vulcanized molded product including a plate-shaped portion 18 and an outer cylinder member 14, and the plate-shaped portion 18 and the outer cylinder member 14 are formed as an integrally vulcanized molded product. It is vulcanized and adhered to the body 16 when the main body rubber elastic body 16 is molded.

The upper portion 30 of the main body rubber elastic body 16 is located between the plate-shaped portion 18 of the inner shaft member 12 and the expanded portion 22 of the outer cylinder member 14 in the vertical direction, and the outer cylinder member 14 is located on the outer peripheral surface 31. Not stuck. As a result, the outer peripheral surface 31 of the upper portion 30 of the main body rubber elastic body 16 is a free surface exposed to the outer circumference between the plate-shaped portion 18 and the expanded-shaped portion 22. The outer peripheral surface 31 of the upper portion 30 of the exposed main body rubber elastic body 16 has a cross-sectional shape that is concave toward the outer circumference.

The shaft body 20 of the inner shaft member 12 is inserted into the hollow portion 24 of the rubber elastic body 16 from the opening 28 on the side opposite to the fixed side of the plate-shaped portion 18. Then, the upper surface of the shaft main body 20 is abutted against the lower surface of the inner peripheral portion of the plate-shaped portion 18 constituting the integrally vulcanized molded product of the main body rubber elastic body 16 and overlapped. The lower end of the shaft body 20 projects downward from the opening 28 of the cavity 24 in a state where the upper surface of the shaft body 20 is abutted against the plate-shaped portion 18.

The hollow portion 24 of the main body rubber elastic body 16 extends axially from the opening 28 at the lower end on the outer peripheral surface of the shaft main body 20 of the inner shaft member 12 toward the plate-shaped portion 18. The shaft body 20 of the inner shaft member 12 is inserted into the cavity 24 of the rubber elastic body 16 and extends in the axial direction, and the outer peripheral surface of the shaft body 20 is separated from the inner surface 26 of the cavity 24 inwardly. There is.

A large diameter portion 32 is integrally formed on the upper portion of the shaft body 20 inserted into the cavity portion 24. The large diameter portion 32 projects from the outer peripheral surface of the shaft body 20 toward the inner surface 26 of the cavity portion 24 toward the outer circumference, and is located at the upper end of the cavity portion 24. The outer peripheral surface of the large diameter portion 32 is a smoothly continuous deformation control surface 34. The deformation control surface 34 is a curved surface that is continuous with a substantially constant cross-sectional shape over the entire circumference. The upper portion of the deformation control surface 34 is an overlapping region 36, and the lower portion is a release region 38.

The overlapping region 36 has a substantially cylindrical surface, and extends along the inner surface 26 of the cavity 24 over the entire circumference in a state where the shaft body 20 is inserted and arranged in the cavity 24. The overlapping region 36 of the present embodiment is in contact with the inner surface 26 of the cavity 24. The overlapping region 36 may be in contact with the inner surface 26 of the cavity 24 in a 0-touch state in which the contact pressure is substantially 0, or the overlapping region 36 may be in contact with the inner surface 26 of the cavity 24 at a predetermined contact pressure greater than 0. It may be pressed. Further, as long as the overlapping region 36 extends along the inner surface 26 of the cavity portion 24, there may be a gap with respect to the inner surface 26 of the cavity portion 24 partially or substantially entirely.

The release region 38 is continuously provided below the overlapping region 36. The release region 38 includes a first tapered surface 40 whose diameter gradually decreases downward from the overlapping region 36, a tubular surface 42 extending below the first tapered surface 40 with a substantially constant diameter, and a tubular surface. It is provided with a second tapered surface 44 whose diameter gradually decreases downward from 42. As described above, the release region 38 includes a portion in which the diameter dimension becomes substantially constant, but the diameter becomes smaller as a whole downward. As a result, the release region 38 is separated from the inner surface 26 of the cavity 24 toward the inner circumference. The distance between the release region 38 and the inner surface 26 of the cavity 24 gradually increases from the overlapping region 36 toward the opening 28 of the cavity 24.

Since the release region 38 has the tubular surface 42, the overlapping region 36 and the tubular surface 42 of the release region 38 are provided in a stepped shape. As a result, the deformation control surface 34 has a stepped shape having a plurality of steps in which the height of protrusion from the shaft body 20 is stepwise different. The overlapping region 36 and the tubular surface 42 provided in a stepped shape are continuously provided by being connected in the axial direction in a smooth shape without break points by the first tapered surface 40, and the deformation control surface 34 is provided. It has a smooth curved surface.

The portion of the inner shaft member 12 below the release region 38 is separated from the inner surface 26 of the cavity portion 24 inwardly. As a result, between the inner shaft member 12 and the inner surface 26 of the cavity 24, a recess extending in the axial direction is formed in an annular shape over the entire circumference.

As shown by the alternate long and short dash line in FIG. 1, a stopper protrusion 46 projecting into the cavity 24 is provided separately from the large diameter portion 32 with respect to a portion of the inner shaft member 12 below the release region 38. You can also do it. The stopper protrusion 46 is provided, for example, so as to project from the outer peripheral surface of the shaft body 20 toward the inner surface 26 of the cavity 24 toward the outer periphery in the intermediate portion in the depth direction (axial direction) of the cavity 24. The stopper protrusion 46 may be integrally formed with the inner shaft member 12, or may be a separate member from the inner shaft member 12 and fixed to the inner shaft member 12.

If such a stopper protrusion 46 is provided in the middle portion of the cavity 24 in the depth direction, the stopper protrusion 46 abuts on the outer cylinder member 14 via the main body rubber elastic body 16 to cause the main body rubber. The amount of deformation of the elastic body 16 is limited to improve durability. Moreover, the stopper protrusion 46 abuts on the inner surface 26 of the cavity 24, and the inner surface 26 of the cavity 24 is restrained from being deformed, so that the concentration of strain on the inner surface 26 of the main body rubber elastic body 16 is prevented. Further improvement in the durability of the main body rubber elastic body 16 is realized.

In the large diameter portion 32, the overlapping region 36 is located above the outer cylinder member 14, and the overlapping region 36 is arranged on the inner circumference of the upper portion 30 of the main body rubber elastic body 16. As a result, the outer peripheral surface of the portion of the main body rubber elastic body 16 located on the outer peripheral side of the overlapping region 36 is a free surface that is not fixed to the outer cylinder member 14. In the present embodiment, the upper half portion of the release region 38 in the large diameter portion 32 is also arranged on the inner circumference of the upper portion 30 of the main body rubber elastic body 16.

In the engine mount 10, the inner shaft member 12 is attached to a power unit (not shown), and the outer cylinder member 14 is attached to a vehicle body (not shown), and the power unit and the vehicle body are vibration-proof connected via the engine mount 10.

In such a state where the engine mount 10 is mounted on the vehicle, when vibration is input between the inner shaft member 12 and the outer cylinder member 14 and the inner shaft member 12 is displaced with respect to the outer cylinder member 14, the main body rubber elasticity The body 16 is elastically deformed. The spring constant of the main body rubber elastic body 16 is appropriately adjusted by providing the hollow portion 24 in the main body rubber elastic body 16, and excellent vibration isolation performance is exhibited.

When a large load in the vertical direction is input between the inner shaft member 12 and the outer cylinder member 14 and the main body rubber elastic body 16 is greatly elastically deformed, the durability of the main body rubber elastic body 16 is ensured. That is, when the main body rubber elastic body 16 is compressed between the plate-shaped portion 18 of the inner shaft member 12, the expanded-shaped portion 22 of the outer cylinder member 14, and the inner flange-shaped portion 23, as shown in FIG. The rubber elastic body 16 of the main body is elastically deformed so as to bulge on the inner surface 26 of the cavity 24 and the outer peripheral surface 31 of the upper portion 30, respectively. Then, the contact region where the inner surface 26 of the cavity portion 24 abuts on the deformation control surface 34 of the large diameter portion 32 expands from the overlapping region 36 toward the release region 38, and the main body rubber elastic body 16 of the deformation control surface 34 It contacts not only the overlapping region 36 but also the release region 38. As a result, the deformation of the inner surface 26 of the cavity 24 is non-linearly controlled by the deformation control surface 34 of the large diameter portion 32, so that local strain concentration is prevented on the inner surface 26 of the cavity 24, and the main body The durability of the rubber elastic body 16 is improved.

The deformation control surface 34 of the large diameter portion 32 includes an overlapping region 36 and a release region 38, and when the main body rubber elastic body 16 is elastically deformed, the main body rubber elastic body 16 is in contact with the deformation control surface 34. However, as the input load increases, it expands from the overlapping region 36 toward the release region 38. As a result, when the input load is small and the amount of deformation of the main body rubber elastic body 16 is small, the restraint region of the main body rubber elastic body 16 by the deformation control surface 34 is narrow, and a soft spring characteristic with a small static spring constant is realized. Can be done. When the input load is large and the amount of deformation of the main body rubber elastic body 16 is large, the restraint region of the main body rubber elastic body 16 by the deformation control surface 34 expands and widens to the release region 38, and is localized in the main body rubber elastic body 16. Concentration of distortion is avoided. As described above, when a small load that does not affect the durability of the main body rubber elastic body 16 is input, excellent vibration isolation performance is realized due to the soft spring characteristics, and a large load that may damage the main body rubber elastic body 16 is feared. At the time of input, the deformation of the main body rubber elastic body 16 is restricted by the deformation control surface 34 in a wider range, and the durability of the main body rubber elastic body 16 is ensured.

The deformation control surface 34 is provided with a plurality of steps in which the overlapping region 36 and the tubular surface 42 of the release region 38 are stepwise different in protrusion height. Further, the tubular surface 42 of the overlapping region 36 and the release region 38 is smoothly connected in the axial direction by the first tapered surface 40, and the deformation control surface 34 is a smooth curved surface as a whole. As a result, the contact region of the main body rubber elastic body 16 with the deformation control surface 34 gradually increases as the input load increases. Therefore, the soft spring characteristics when the deformation amount of the main body rubber elastic body 16 is small and the strain dispersion when the deformation amount of the main body rubber elastic body 16 is large are effectively realized. Moreover, since the deformation control surface 34 is a smooth curved surface, stress concentration on the main body rubber elastic body 16 due to the deformation control surface 34 being pressed is unlikely to occur.

The large diameter portion 32 constituting the deformation control surface 34 is integrally formed with the shaft body 20 of the inner shaft member 12. As a result, the inner shaft member 12 provided with the deformation control surface 34 can be realized by a simple structure having a small number of parts.

The outer peripheral surface 31 of the upper portion 30 of the main body rubber elastic body 16 located on the outer peripheral side of the overlapping region 36 is a free surface that is not fixed to the outer cylinder member 14. As a result, even when the inner surface 26 of the cavity 24 in the main body rubber elastic body 16 is restrained from being deformed by the overlapping region 36, it becomes easy to realize a soft spring characteristic.

The deformation control surface 34 is continuous over the entire circumference in the circumferential direction, and the overlapping region 36 of the deformation control surface 34 extends along the inner surface 26 of the cavity 24 over the entire circumference. Therefore, local strain concentration of the main body rubber elastic body 16 is avoided over the entire circumference in response to a large load input, and the durability of the main body rubber elastic body 16 is improved.

Since the cavity 24 extends in the axial direction with a substantially constant inner diameter, strain is less likely to be concentrated on the inner surface 26 of the cavity 24 when the main body rubber elastic body 16 is elastically deformed.

FIG. 4 shows an engine mount 50 for an automobile as a second embodiment of a tubular anti-vibration device having a structure according to the present invention. The engine mount 50 has a structure in which the inner shaft member 52 and the outer cylinder member 14 are connected by a main body rubber elastic body 16. In the following description, the members and parts substantially the same as those in the first embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted.

The inner shaft member 52 has a plate-shaped portion 18 and a shaft main body 54 extending downward from the inner peripheral end portion of the plate-shaped portion 18. The shaft body 54 has a small-diameter cylindrical shape that extends linearly in the vertical direction. A flange-shaped portion 56 projecting to the outer periphery is provided at the upper end of the shaft main body 54 over the entire circumference, and the fixing strength between the shaft main body 54 and the plate-shaped portion 18 is secured.

A deformation control member 58 is attached to the shaft body 54 of the inner shaft member 52. The deformation control member 58 is a separate member from the inner shaft member 52. The deformation control member 58 has an annular shape and is externally fitted and fixed to the shaft body 54. The outer peripheral surface of the deformation control member 58 is a deformation control surface 34 having an overlapping region 60 and a release region 62.

The overlapping region 60 is a cylindrical surface extending along the inner surface 26 of the cavity 24 of the main body rubber elastic body 16. The overlapping region 60 is provided in an intermediate portion in the vertical direction of the deformation control member 58.

The release region 62 has a tapered surface that gradually decreases in diameter toward the bottom. The release region 62 of the present embodiment is a curved surface that is convex toward the outer circumference. In the first embodiment, the overlapping region 36 and the release region 38 have a stepwise shape, but in the present embodiment, the overlapping region 60 and the release region 62 are provided in a continuous shape instead of a stepwise shape. ing. The release region 62 is gradually separated from the inner surface 26 of the cavity 24 of the main body rubber elastic body 16 toward the inner circumference as it goes downward from the overlapping region 60.

The deformation control member 58 is fitted to the outer peripheral surface of the shaft main body 54 constituting the inner shaft member 52 and fixed to the shaft main body 54. An abutting portion 64 projecting upward is provided at the inner peripheral end portion of the deformation control member 58, and the abutting portion 64 is superposed on the flange-shaped portion 56 of the shaft body 54 in a contact state from below. As a result, the deformation control member 58 is positioned in the vertical direction with respect to the shaft main body 54.

As shown in FIG. 5, the main body rubber elastic body 16 is formed as an integrally vulcanized molded product including not only the plate-shaped portion 18 of the inner shaft member 52 and the outer cylinder member 14 but also the shaft main body 54 of the inner shaft member 52. ing. The plate-shaped portion 18 and the shaft main body 54 are fixed to each other by means such as welding in advance before vulcanization molding of the main body rubber elastic body 16, for example.

Then, a separate deformation control member 58 is attached to the shaft body 54 of the inner shaft member 52 that has been vulcanized and adhered to the rubber elastic body 16. The deformation control member 58 is inserted into the hollow portion 24 of the main body rubber elastic body 16 from the lower opening 28, and is provided so as to project from the inner shaft member 52 toward the outer circumference as shown in FIG. Be done. The overlapping region 60 of the deformation control member 58 attached to the shaft body 54 has a tubular shape along the inner surface 26 of the cavity 24, and is overlapped with the inner surface 26 of the cavity 24 in an abutting state. The release region 62 of the deformation control member 58 is located on the inner circumference of the inner surface 26 of the cavity portion 24, and a gap is provided between the release region 62 and the inner surface 26 of the cavity portion 24.

In the engine mount 50 of the present embodiment, the deformation control surface 34 is composed of another member that is externally fitted and fixed to the inner shaft member 52. Therefore, for example, the deformation control member 58 provided with the deformation control surface 34 is fitted and fixed to the shaft body 54 of the inner shaft member 52 that has been vulcanized and adhered at the time of molding the main body rubber elastic body 16. Can be provided with.

In the engine mount 50, when a compressive load in the vertical direction acts on the main body rubber elastic body 16, as shown in FIG. 6, the inner peripheral surface (inner surface 26) of the main body rubber elastic body 16 bulges into the cavity 24. ) Comes into contact with not only the overlapping region 60 of the deformation control member 58 but also the release region 62. As a result, the durability of the main body rubber elastic body 16 can be improved by dispersing the strain of the main body rubber elastic body 16 as in the first embodiment.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the specific description thereof. For example, the deformation control surface does not have to have the same cross-sectional shape over the entire circumference, and the shape may change in the circumferential direction. The deformation control surface is not necessarily limited to the one that is continuously formed over the entire circumference, and may be partially provided in the circumferential direction, or may be provided in plurality in the circumferential direction.

The specific shape of the deformation control surface is not particularly limited as long as the overlapping region and the release region are provided. For example, the release region may have a multi-stage structure in which the protrusion heights are gradually different. According to this, the contact area of the main body rubber elastic body with the deformation control surface changes in multiple stages according to the amount of deformation of the main body rubber elastic body, so that the strain dispersion of the main body rubber elastic body is more effective. Can be planned.

When the engine mount 10 is mounted on the vehicle, the shared support load of the power unit is input to the main body rubber elastic body 16, so that the inner surface 26 of the main body rubber elastic body 16 becomes at least a part of the release region 38 of the inner shaft member 12. You may make it come into contact with. In short, the contact region of the main body rubber elastic body 16 with the deformation control surface 34 is expanded from the overlapping region 36 toward the release region 38 by further inputting a load such as vibration in the mounted state on the vehicle. Alternatively, it may be expanded from the overlapping region 36 toward the release region 38 by inputting a shared support load of the power unit or the like when the vehicle is mounted. By inputting the shared support load of the power unit, the contact region of the main body rubber elastic body 16 with the deformation control surface 34 expands, so that the ratio of the spring constant in the axial direction to the spring constant in the direction perpendicular to the axis can be easily adjusted. That is, the ratio of the spring constant in the direction perpendicular to the axis to the spring constant in the axial direction can be greatly adjusted, and the degree of freedom in tuning the spring constant can be increased.

Further, the deformation control surface on the inner shaft member side is provided with a maximum protrusion in the overlapping region, so that the portion extending from the maximum protrusion to the release region does not have an inclination in the direction in which the protrusion height increases. , It is desirable to extend in the axial direction with a surface having the same protrusion height or a surface with a smaller protrusion height. Further, in the portion extending from the maximum protrusion to the release region, it is preferable that the inclination angle in the axial direction changes gradually or stepwise, and at the change point of the inclination angle, the tangent line is smoothly made common. It is desirable that they are connected and change.

The inner surface of the cavity of the rubber elastic body of the main body that contacts the deformation control surface on the inner shaft member side also has an inner diameter from the bottom side (plate-shaped side of the inner shaft member) toward the opening side (opposite the plate-shaped part). It is desirable that they extend axially with the same inner diameter or a surface with a larger inner diameter so that the dimensions do not become smaller. For the bottom surface of the cavity, the punching taper of the molding die at the time of molding can be taken into consideration. Incidentally, in the embodiment shown in FIGS. 2 and 5, the inner surface 26 of the cavity 24 of the main body rubber elastic body 16 is slightly below the upper end rubber bite portion and substantially over the entire length in the axial direction. It is a tapered inner peripheral surface that expands downward at a constant inclination angle.

Then, due to the relative combination of the deformation control surface on the inner shaft member side and the inner surface of the hollow portion of the rubber elastic body of the main body, the distance between the facing surfaces in the direction perpendicular to the axes of both is at least from the bottom side of the hollow portion in the release region. It is desirable that the distance between the facing surfaces is the same or the distance between the facing surfaces increases so that the distance does not become narrower toward the opening side. However, the deformation control surface on the inner shaft member side and the inner surface of the cavity of the rubber elastic body of the main body have different rates of change in the inclination angle in the axial direction, so that the contact area is non-linear when the load is input. It can be set to increase to, which allows the non-linear rise of the spring characteristics to be set.

Further, since the inner peripheral end of the hollow portion 24 of the main body rubber elastic body 16 in the above embodiment is not folded back toward the opening side, the inner peripheral end on the bottom side is tentatively different from the deformation control surface 34 on the inner shaft member 12 side. Even if they are not in close contact with each other, local stress and strain concentration can be avoided as compared with the conventional structure. The deformation control surface 34 on the inner shaft member 12 side and the inner surface 26 of the cavity 24 of the main body rubber elastic body 16 are at least in a state where they are mounted on a vehicle and a support load such as a power unit is applied. It is desirable that the inner surface 26 of the cavity 24 of the main body rubber elastic body 16 is in contact with each other without a gap in, for example, the maximum outer diameter portion of the overlapping region 36 of 34. However, in the above-described embodiment, the stress at the time of load input is generated between the axially facing surfaces of the large diameter portion 32 and the plate-shaped portion 18, and between the axially opposed surfaces of the deformation control member 58 and the flange-shaped portion 56. It is not necessary that the main body rubber elastic body 16 is filled, and it may be a vacant space or the like.

Further, in the above-described embodiment, the outer cylinder member 14 is provided with an expanded portion 22 that is curved and spreads upward in the axial direction, and a flange-shaped portion is provided at the upper end portion in the axial direction of the outer cylinder member 14. On the other hand, in the lower portion in the axial direction, a tubular portion 21 extending in the axial direction with a substantially constant diameter dimension is formed, and an inner flange-shaped portion 23 that can be used for reinforcement or a stopper is provided at the lower end opening. Was there. The deformation control surface 34 is provided at a position where the small-diameter tubular portion 21 provided in the axially lower portion of the outer tubular member 14 is displaced upward in the axial direction, and the deformation control surface 34 is provided. The rubber volume is secured between the surface facing the outer cylinder member 14 and the outer cylinder member 14. As illustrated by virtual lines in FIGS. 3 and 6, the stopper protrusion 46 in the direction perpendicular to the axis is positioned so as to face the small-diameter tubular portion 21 of the outer cylinder member 14 in the direction perpendicular to the axis. It has been set and the stopper function has been improved.

When the deformation control member 58 constituting the deformation control surface 34 is a separate member from the shaft body 20, the shaft body 20 and the deformation control member 58 are combined with each other for forming the main body rubber elastic body 16. It may be set in a mold and vulcanized and adhered to the main body rubber elastic body 16. In short, when a separate deformation control member 58 is adopted, the deformation control member 58 is limited to a mode in which the main body rubber elastic body 16 is attached to the shaft main body 20 after vulcanization molding as in the second embodiment. Not done.

The tubular anti-vibration device is not necessarily limited to a rotationally symmetric shape, and may be, for example, an elliptical shape in the axial direction.

10,50 engine mount (cylindrical anti-vibration device)
12, 52 Inner shaft member 14 Outer cylinder member 16 Main body rubber elastic body 18 Plate-shaped part 20, 54 Shaft main body 21 Cylindrical part 22 Expanded part 23 Inner flange-shaped part 24 Cavity part 26 Inner surface 28 Opening 30 Upper part 31 Outer circumference Surface 32 Large diameter part 34 Deformation control surface 36,60 Overlapping area 38,62 Release area 40 First tapered surface 42 Cylindrical surface 44 Second tapered surface 46 Stopper protrusion 56 Flange-shaped part 58 Deformation control member 64 Contact Department

Claims (8)

In a tubular anti-vibration device in which an inner shaft member having a plate-shaped portion at one end in the axial direction and an outer tubular member having a spread-shaped portion at one end in the axial direction are connected by a rubber elastic body of the main body.
The main body rubber elastic body is provided with a cavity portion that opens at the other end surface in the axial direction and extends axially toward the plate-like portion on the outer peripheral surface of the inner shaft member.
The inner shaft member is provided with a deformation control surface protruding on the outer peripheral surface, and is provided with a deformation control surface.
The deformation control surface is provided with an overlapping region that extends along the inner surface of the cavity and a release region that gradually separates from the inner surface of the cavity from the overlapping region toward the opening side of the cavity. ,
A tubular anti-vibration device in which a contact region of the main body rubber elastic body with the deformation control surface expands from the overlapping region toward the release region as the input load increases. The tubular anti-vibration device according to claim 1, wherein the deformation control surface is a curved surface in which a plurality of stages having different protrusion heights are smoothly connected in the axial direction. The tubular anti-vibration device according to claim 1 or 2, wherein the deformation control surface is formed of a large-diameter portion integrally formed with the inner shaft member. The tubular anti-vibration device according to any one of claims 1 to 3, wherein the deformation control surface is formed of another member that is fitted and fixed to the inner shaft member. The tubular anti-vibration device according to any one of claims 1 to 4, wherein a stopper protrusion protruding from the inner shaft member into the cavity is provided in an intermediate portion in the depth direction of the cavity. The tubular protection according to any one of claims 1 to 5, wherein the outer peripheral surface of the main body rubber elastic body located on the outer peripheral side of the overlapping region is a free surface that is not fixed to the outer tubular member. Shaking device. The aspect according to any one of claims 1 to 6, wherein the deformation control surface is continuous over the entire circumference in the circumferential direction, and the overlapping region of the deformation control surface extends along the inner surface of the cavity portion over the entire circumference. The described tubular anti-vibration device. The tubular vibration isolator according to any one of claims 1 to 7, wherein the cavity portion extends in the axial direction with a substantially constant inner diameter.

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