JPH0625570B2 - Cylindrical mounting device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cylindrical mount device, and in particular, a novel structure in which an improvement in vibration isolation performance against vibrations in the middle to high frequency range can be advantageously achieved with a simple structure. The present invention relates to a cylindrical mount device.

(Background Art) Conventionally, a mount device that is interposed between two members that constitute a vibration transmission system and that connects both members in a vibration-proof manner or supports one member in a vibration-proof manner with respect to the other member. As a kind, as disclosed in Japanese Utility Model Laid-Open No. 57-59119 and Japanese Patent Laid-Open No. 58-72747, an inner tubular metal member and an outer tubular metal member arranged concentrically or eccentrically with each other are provided. A so-called cylindrical mount device is known in which a rubber elastic body interposed between the two is integrally connected. Further, in such a tubular mount device, a compact mount size can be advantageously realized, and a stopper function for restricting the relative displacement amount of the inner and outer tubular metal fittings when an excessive vibration load is input is easy. Can be added to the F engine of a horizontal engine.
It has been favorably used as an engine mount for an F-type automobile.

However, in the cylindrical mount device having such a structure, since the rubber elastic body is used as the vibration isolator, the resonance frequency of the rubber elastic body is reached due to the resonance phenomenon of the rubber elastic body. At the time of vibration input in the frequency range up to, the dynamic spring constant increases as the frequency of the input vibration increases. In the conventional cylindrical mount, the resonance of the rubber elastic body appears in the frequency range of about 300 to 700 Hz. Therefore, when applied to an automobile engine mount, a muffled sound such as engine transmitted sound or It was difficult to sufficiently prevent high-frequency vibrations, and therefore, especially with the recent higher demands for quietness and riding comfort of automobiles, the vibration-damping characteristics in such high-frequency range have been improved. There is a longing for improvement.

(Problem to be Solved) Here, the present invention has been made in the background of the above circumstances, and the problem to be solved is to:
The rise of the dynamic spring constant due to the resonance phenomenon of the rubber elastic body can be effectively avoided, and the improvement of the vibration isolation performance over a wide frequency range of the middle to high frequency range can be advantageously realized with a simple structure. An object of the present invention is to provide a cylindrical mount device that can be obtained.

(Solution) In order to solve such a problem, in the present invention, an inner tubular metal member and an outer tubular metal member that is concentrically or eccentrically arranged outside the inner tubular metal member at a predetermined distance. Between
By interposing a rubber elastic body, and forming a space penetrating in the axial direction on both sides in the main vibration input direction between the inner and outer tubular metal fittings, sandwiching the inner tubular metal fitting, the inner tubular metal fitting and the outer tubular material are formed. The metal fittings are integrally and elastically connected to each other by the two elastic connecting portions extending between the facing surfaces of the inner and outer tubular metal fittings, and at least one of the elastic connecting portions is extended from the central portion in the extending direction. A tubular mounting device comprising a support arm that is inclined at a predetermined angle with respect to the main vibration input direction and projects into the space, and a predetermined mass body is attached in a cantilever state by the support arm. To do.

(Examples) Hereinafter, in order to more specifically clarify the present invention, examples of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 show a specific example in which the present invention is applied to an engine mount for an FF type automobile. In these figures, 10 is an inner cylinder metal fitting, which is formed in a thick-walled cylindrical shape.

Further, on the outer side in the radial direction of the inner tubular member 10, a large-diameter cylindrical outer tubular member 12 is arranged at a predetermined distance in the radial direction and eccentric by a predetermined amount.

Further, between the inner tubular metal fitting 10 and the outer tubular metal fitting 12, rubber elasticity is applied to the outer peripheral surface of the inner tubular metal fitting 10 and the inner peripheral surface of the outer tubular metal fitting 12 by vulcanization adhesion. The body 14 is interposed. Here, in the rubber elastic body 14, the inner and outer cylindrical metal fittings 10 and 12 are
On the side where the distance between the two metal fittings is large in the eccentric direction, there is provided a first cavity 16 that penetrates in the axial direction with a substantially fan-shaped cross-sectional shape, while on the side where the distance between the two metal fittings is small. Is provided with a second cavity 18 which penetrates in the axial direction and has a crescent-shaped cross section that extends over substantially half the circumference.

That is, the rubber elastic body 14 is allowed to exist only between the first hollow space 16 and the second hollow space 18 between the inner and outer cylindrical metal fittings 10 and 12, and as a result, the rubber elastic body 14 as a whole is omitted. Two elastic connecting portions 20, 20 extending in the radial direction are respectively formed between the inner tubular metal fitting 10 and the outer tubular metal fitting 12 with a central included angle having a V-shaped cross section. 12 is substantially integrally and elastically connected only by these elastic connecting portions 20, 20.

A stopper portion 22 is integrally formed in the first cavity 16 by the rubber elastic body 14 so as to project from the outer tubular metal fitting 12 side toward the inner tubular metal fitting 10 side at a predetermined height. The amount of displacement of the inner tubular metal fitting 10 relative to the outer tubular metal fitting 12 toward the first space 16 is determined by the stopper portion 2 of the inner tubular metal fitting 10.
It can be defined by abutting against 2.

In addition, in the elastic connecting portions 20 and 20, at a predetermined height toward the inside of the second cavity 18 substantially parallel to the eccentric direction of the inner and outer tubular metal fittings 10 and 12 at the respective radial center portions. A support arm portion 24 is formed integrally with the rubber elastic body 14 over a substantially entire length in the axial direction, the support arm portion 24 having a shape in which the tip end portion is bent inward in the opposing direction.

Furthermore, mass members 26, which are rod-shaped mass bodies and are arranged substantially parallel to the mount axis direction, are integrally fixed to the protruding ends of the support arms 24, 24, respectively. In other words, the mass member 26 is connected to the elastic connecting portion 20 via the support arm portion 24,
It is supported.

In such an engine mount, the inner cylinder fitting 10 and the outer cylinder fitting 1 are arranged in a state where the weight of the engine unit is exerted in the eccentric direction of the inner and outer cylinder fittings 10 and 12.
2 are attached to either the vehicle body side or the engine unit side, respectively, so that they can be interposed between the vehicle body and the engine unit, and as shown in FIG. In such a mounted state, the inner and outer tubular metal fittings 10 and 12 are positioned substantially concentrically due to the weight of the engine unit loaded. And again, under such wearing condition,
The input vibration exerted between the inner and outer cylindrical metal fittings 10 and 12 is mainly input in the eccentric direction of the inner and outer cylindrical metal fittings 10 and 12 (vertical direction in FIG. 4).

In the engine mount according to the present embodiment, in particular, the elastic connecting portions 20 and 20 to which the load input between the inner and outer tubular metal fittings 10 and 12 is exerted depend on the load of the engine unit. Since the inner tubular member 10 is positioned on the radial side where it can be displaced, generation of tensile stress in the elastic connecting portions 20 and 20 can be prevented as much as possible, and thus excellent durability is advantageous. It can be secured.

Further, in the mounted state of the engine mount, the support arm portion 24 that supports the mass member 26 is
As is clear from FIG. 4, each of the mass members supported by the support arm 24 is projected from the elastic coupling portion 20 in a state of being inclined at a predetermined angle with respect to the vibration input direction. 26 is positioned inside the mount by a predetermined dimension from the standing position of the support arm 24 with respect to the elastic coupling portion 20.

That is, in the engine mount having such a structure, when vibration is input between the inner and outer cylindrical metal fittings 10 and 12, such input vibration is caused based on elastic deformation of the elastic coupling portions 20 and 20. Although the transmission is alleviated or prevented, when the present inventor conducted an experiment there, as described above, the mass member 26 is supported by the elastic connecting portion 20 via the support arm portion 24. In the engine mount having the above structure, as shown in FIG. 5, until the input vibration reaches a certain frequency, the dynamic spring constant of the mount gradually decreases as the frequency of the input vibration increases. It has become clear that it exhibits extremely characteristic frequency characteristics, which is completely opposite to that of conventional mounts. In FIG. 5, the elastic connecting portion 20
Also, the results of measuring the frequency characteristics of the similar vibration isolation performance for the engine mount having the conventional structure not including the mass member 26 will be shown as a comparative example.

By the way, the details of the action and principle of exhibiting such an effect are not yet clear, but first, when vibration is input between the inner and outer tubular metal fittings 10 and 12, the inner tubular metal fitting 10 is exposed to vibration. When relative displacement with respect to the tubular fitting 12 is caused, as shown in FIG. 4, the mass member 26 is moved in a direction opposite to the displacement direction of the inner tubular fitting 10 based on its inertial force. It is thought that the power of is generated. Then, based on the inertial force of the mass member 26, a predetermined moment is exerted on the elastic connecting portion 20 as a vibration isolator via the support arm portion 24, and this moment is transmitted by the vibration. It is presumed that it acts to reduce the rate.

In addition, the effect of reducing the vibration transmissibility is as follows.
6 is elastically supported by the elastic connecting portion 20, and is generated by the vibration input between the inner and outer cylindrical metal fittings 10 and 12 with respect to the elastic connecting portion 20. It is considered that the deformation is caused by the deformation having a phase opposite to that of the deformation. When the vibration is input in a frequency range higher than the natural frequency (resonance frequency) of the vibration system constituted by the mass member 26, Since the deformation exerted on the elastic coupling portion 20 by such a vibration system is in the same phase as the deformation caused by the vibration input between the inner and outer cylindrical metal fittings 10, 12, the vibration transmissibility is increased on the contrary. Presumed to be.

As a result of experiments and studies conducted by the present inventor on the vibration damping characteristics of the engine mount having the above-described structure, as shown in FIG. 5, the mass member 26 is made of rubber which is lighter than metal. By setting the natural frequency of the vibration system including the mass member 26 to the higher frequency side,
That the low motion effect of the mount can be exhibited, and further,
As shown in FIG. 6, by embedding the reinforcing plate 28 in the support arm portion 24 that supports the mass member 26, its rigidity is increased, and the natural vibration of the vibration system including the mass member 26 is increased. It was confirmed that by setting the number to the higher frequency side, the mount's low dynamic spring effect can be exerted against the input vibration in the higher frequency range, as shown in FIG. 7. It is considered that this is obviously related to the vibration of the vibration system including the mass member 26 and the phase thereof. From this point as well, the above assumption can be convinced to some extent. .

As is clear from this, in the engine mount having the above-described structure, by adjusting the weight of the mass member 26 and the rigidity of the support arm portion 24, the low dynamic spring of the mount vibration isolation characteristic is exhibited. The frequency range to be adjusted can be tuned as appropriate.

Therefore, in such an engine mount, the increase in the mount dynamic spring constant with the increase in the frequency of the input vibration is
This can be completely avoided, and as a result, the vibration transmissibility at the time of vibration input of tens to hundreds of Hz such as muffled sound or vibration can be advantageously reduced, and the improvement of vehicle ride comfort can be achieved very effectively. You will get it.

Further, in such an engine mount, it suffices to elastically support the mass member 26 by the support arm portion 24 with respect to the elastic connecting portion 20, and in particular, in the present embodiment, the support arm portion 24 is made of rubber. Since the elastic body 14 is integrally formed, the elastic connecting portion 20 can be simultaneously molded, and further, the mass member 26 can be vulcanized and bonded at the time of the molding, so that the structure is simple and excellent. It can be manufactured with the following manufacturability.

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

For example, the elastic connecting portions 20 and 20 do not necessarily have to be formed in a V-shaped cross section, and when an initial load is not applied, a shape that extends linearly with an included angle of 180 ° is also advantageous. It can be adopted.

Further, the support arm portion 24 can also be formed of a material such as metal, and its shape is such that the moment due to the inertial force of the mass member 26 can be effectively exerted on the elastic connecting portion 20. However, the shape is not limited to the embodiment.

Further, the shape of the mass member 26 is not limited to the cylindrical shape as illustrated, and when the support arm portion 24 itself is made to function as a mass member, it is not necessary to provide a special mass member.

Further, the support arm portion 24 that supports the mass member 26 may be provided only on the one elastic coupling portion 20 side,
Further, it can be provided on the side of the first void 16 and can be formed in both the first and second voids 16 and 18.

Furthermore, the outer tubular fitting 12 can be formed in a shape other than a cylinder, such as a rectangular tubular shape, whereby the space for disposing the mass member 26 can be more effectively ensured.

In addition, in the above embodiment, one specific example of the present invention applied to an engine mount for an automobile is shown.
It goes without saying that the present invention can be effectively applied to suspension bushes for automobiles and mounts for various devices.

Although not listed one by one, the present invention can be carried out in variously modified, modified, improved, etc. modes based on the knowledge of those skilled in the art. It goes without saying that all of them are included in the scope of the present invention without departing from the spirit.

(Effects of the Invention) As is apparent from the above description, in the tubular mounting device according to the present invention, the support arm attached to the elastic connecting portion, which is generated when vibration is input between the inner and outer tubular metal fittings. The vibrating action of the vibrating system including the mass body and the elastic coupling portion can avoid an increase in the mount dynamic spring constant associated with an increase in the frequency of the input vibration, and conversely lower the mount dynamic spring up to a certain frequency range. Therefore, for input vibration in the middle to high frequency range,
It is possible to exert an extremely excellent anti-vibration effect.

Further, in such a cylindrical mount device, there is also an advantage that the vibration damping characteristics can be extremely easily adjusted by adjusting the mass of the mass body and the rigidity of the support arm.

Further, the tubular mount device according to the present invention has an extremely simple structure in which a predetermined mass body is supported by a support arm with respect to an elastic connecting portion that connects the inner and outer tubular metal fittings. Therefore, its manufacture can be provided easily and inexpensively.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing one specific example of the present invention applied to an automobile engine mount, FIG. 2 is a II-II cross-sectional view in FIG. 1, and FIG. FIG. 3 is a perspective view showing such an engine mount with a part thereof cut away. Further, FIG. 4 is a front explanatory view showing a mounted state of the engine mount shown in FIG. Also, the fifth
The figure shows the measurement result of the frequency characteristic of the vibration isolation performance in the engine mount having the structure as shown in FIG.
It is a graph shown with a comparative example. Further, FIG. 6 is a cross-sectional view showing another specific example of the engine mount for an automobile having the structure according to the present invention, and FIG. 7 shows the measurement result of the frequency characteristic of the vibration isolation performance in the engine mount. 2 is a graph showing the frequency characteristics of the vibration isolation performance in the engine mount having the structure shown in FIG. 1. 10: Inner tubular metal fitting, 12: Outer tubular metal fitting 14: Rubber elastic body, 16: First void 18: Second void, 20: Elastic connection portion 24: Support arm portion, 26: Mass member

Claims (1)

[Claims] 1. A rubber elastic body is interposed between an inner tubular metal member and an outer tubular metal member which is concentrically or eccentrically arranged outside the inner tubular metal member with a predetermined distance therebetween and at the same time, the inner and outer portions thereof are provided. By forming a space that penetrates in the axial direction on both sides in the main vibration input direction between the tubular metal fittings sandwiching the inner tubular metal fitting, the inner tubular metal fitting and the outer tubular metal fitting are respectively formed on the opposing surfaces of the inner and outer tubular metal fittings. The two elastic connecting portions extending in between are integrally and elastically connected to each other, and at least one of the elastic connecting portions is inclined at a predetermined angle with respect to the main vibration input direction from the central portion in the extending direction thereof. Then, a cylindrical mounting device is provided, in which a supporting arm protruding into the space is provided, and a predetermined mass body is attached in a cantilevered state by the supporting arm.