JPH05272575A - Fluid-sealed mounting device - Google Patents

Abstract

PURPOSE:To provide a fluid-sealed mounting device having a new structure and the improved vibration-proof characteristic for input vibrations in the medium/high-frequency areas. CONSTITUTION:A fluid-sealed mounting device is connected with the first fitting metal 10 and the second fitting metal 12 via a rubber elastic body 14, and it is formed with a pressure receiving chamber 38 and an equilibrium chamber 40 communicated via the first orifice passage 68 on both sides across a partition member 36. A through hole 58 extended astride the pressure receiving chamber 38 and the equilibrium chamber 40 is provided on the partition member 36. The first rubber elastic plate 54 and the second rubber elastic plate 56 having larger rigidity against the volume change than that of the first rubber elastic plate 54 are arranged at a preset distance in the through hole 58, and an intermediate chamber 60 communicated with the equilibrium chamber 40 via the second orifice passage 72 having a cross sectional area/length ratio larger than that of the first orifice passage 68 is formed between both rubber elastic plates 54, 56.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fluid-filled mount device,
Particularly, it is suitable for use as an automobile engine mount or the like, which is provided with a plurality of orifice passages and can obtain an excellent vibration-damping effect over a wide frequency range based on the flow action of the fluid that is made to flow through each of the orifice passages. The present invention relates to a fluid-filled mount device.

[0002]

2. Description of the Related Art Conventionally, a first mounting member and a second mounting member, which are spaced apart from each other by a predetermined distance, are provided as a type of a vibration-proof support member such as an engine mount for automobiles. Pressure chambers that are connected by a rubber elastic body and are filled with a predetermined incompressible fluid inside, and part of the wall part is made of a rubber elastic body, causing fluctuations in internal pressure when vibration is input. And an equilibrium chamber in which a part of the wall portion is made of a flexible film and a volume change is allowed, are formed on both sides of the partition member supported by the second mounting member, and There is known a so-called fluid-filled mount device having a structure in which an orifice passage that allows the flow of fluid between the pressure receiving chamber and the equilibrium chamber is provided. In such a fluid-filled mount device, an excellent vibration damping effect, which cannot be obtained only by the rubber elastic body, can be exhibited based on the flow action of the fluid caused to flow through the orifice passage.

By the way, the anti-vibration characteristics required of the anti-vibration support differ depending on the type of the input vibration. For example, in the engine mount for automobiles, for the low-frequency large-amplitude vibration corresponding to shake or bounce. While high damping characteristics are required, low dynamic spring characteristics are required for medium-frequency medium-amplitude vibrations corresponding to idling vibrations and high-frequency small-amplitude vibrations corresponding to muffled noises.

However, in the fluid-filled mount device having the above-described structure, the vibration damping effect exerted based on the resonance action of the fluid flowing in the orifice passage is tuned. It can be effectively used only for input vibration in a limited frequency range, and when the vibration is input in a frequency range higher than the frequency range where the orifice path is tuned, the orifice path is substantially blocked. However, there is a problem in that it is inevitable that the vibration insulation performance is extremely deteriorated due to the increase in the dynamic spring.

Therefore, in the prior art, in order to suppress the increase of the dynamic spring at the time of inputting vibration in the middle to high frequency range, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Publication No. 7-9340, a movable plate is disposed between the pressure receiving chamber and the equilibrium chamber so as to be displaceable by a predetermined distance,
A structure has been proposed in which, based on the displacement of the movable plate, the internal pressure fluctuation of the pressure receiving chamber during vibration input in the middle frequency range is absorbed.

However, even in the mounting device having such a structure, the frequency range in which the low dynamic spring effect is exerted is limited due to the displacement of the movable plate, and when the vibration input in the higher frequency range is more than that, it is substantially effective. As a result, the movable plate cannot be displaced, so that it is not possible to obtain satisfactory vibration damping characteristics for input vibration in a sufficiently wide frequency range. That is, for example, if the orifice passage is tuned to a low frequency range corresponding to shake, etc., and the movable plate is tuned to a medium frequency range corresponding to idling vibration, etc., a high damping effect on input vibration in the low frequency range and a medium frequency range are obtained. Although a low dynamic spring effect can be achieved with respect to the input vibration in the region, it is inevitable that the vibration isolation effect in the high frequency region corresponding to muffled noise will be significantly reduced.

As one measure for solving such a problem, Japanese Patent Publication No. 3-3088 discloses a first movable plate in which the dynamic spring constants of the supporting systems are different between the pressure receiving chamber and the equilibrium chamber. By arranging the first movable plate and the second movable plate in series, based on the principle of the series connection of spring members, a mounting device having a structure for achieving a low dynamic spring effect at the time of vibration input in a high frequency range is provided. ,Proposed.

However, the inventors of the present invention conducted an experiment and conducted a detailed study, and as a result, the first movable plate and the second movable plate having different dynamic spring constants of the supporting systems were arranged in series. However, it was confirmed that the low dynamic spring effect was hardly obtained at the time of vibration input in the high frequency range, and the characteristics were governed by the characteristics of the movable plate with the larger dynamic spring constant. However, such a technique is, so to speak, a theoretical theory that does not consider the resonance action of the fluid, and the effect thereof is hardly expected.

[0009]

The present invention has been made in view of the circumstances as described above, and a problem to be solved by the present invention is to secure vibration-proof characteristics against low-frequency vibration while maintaining a middle-to-high frequency range. It is an object of the present invention to provide a fluid-filled mount device having a novel structure, which has an improved anti-vibration characteristic with respect to input vibration in a range, and can exhibit an excellent anti-vibration effect against input vibration in a wide frequency range.

[0010]

In order to solve such a problem, a feature of the present invention resides in that a first mounting member and a second mounting member, which are arranged at a predetermined distance from each other, are made of a rubber elastic body. Part of the wall part is made of the rubber elastic body, in which a predetermined incompressible fluid is enclosed inside on both sides of the partition member supported by the second mounting fitting while being connected. To form a pressure-receiving chamber in which fluctuations in internal pressure are caused at the time of vibration input, and a balance chamber in which a part of the wall portion is made of a flexible film and whose volume is variable. In a fluid-filled mount device provided with first orifice passages that communicate with each other, with respect to the partition member,
A through hole extending across the pressure receiving chamber and the equilibrium chamber is provided, and a first rubber elastic plate and the first rubber are provided on the pressure receiving chamber side and the equilibrium chamber side in the through hole. By arranging second rubber elastic plates, which have a larger rigidity against volume change than the elastic plates, at a predetermined distance from each other, and fixing each outer peripheral edge portion by such a partition member, An intermediate chamber is formed between the rubber elastic plate and the second rubber elastic plate, and a cross-sectional area between the intermediate chamber and the equilibrium chamber is larger than that of the first orifice passage.
This is because a second orifice passage having a large length ratio is provided.

[0011]

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

First, FIG. 1 shows an automobile engine mount as an embodiment of the present invention. In this figure, 10 and 12 are a first mounting member and a second mounting member, respectively, which are arranged to face each other with a predetermined distance therebetween. Also, these first mounting brackets 1
0 and the second mounting member 12 are elastically connected by a main rubber elastic body 14 interposed therebetween. And in such an engine mount,
The first mounting member 10 and the second mounting member 12 are attached to one of the vehicle body side and the power unit side, respectively, and are interposed between the vehicle body and the power unit, whereby the power unit is attached to the vehicle body. Support the anti-vibration. In addition, under such wearing condition,
In such an engine mount, the first and second mounting brackets 10 and 12 are substantially opposed to each other (almost vertically in FIG. 1).
The weight of the power unit is
Is elastically deformed so that the two mounting brackets 10 and 12 are positioned close to each other by a predetermined distance, and mainly, in a substantially opposing direction of the first and second mounting brackets 10 and 12. The vibration damping effect is exerted against the vibration input to the.

More specifically, the first mounting member 10
Are formed in a substantially disc shape. Further, a mounting bolt 16 projecting to one side is fixedly provided at a substantially central portion of the first mounting member 10, and the mounting bolt 16 allows the mounting bolt 16 to be mounted on the power unit side.

A main rubber elastic body 14 is vulcanized and adhered to the first mounting member 10. The main rubber elastic body 14 has a substantially truncated cone shape as a whole,
It has a recess 18 that opens to the large diameter end surface. And
The first mounting member 10 is vulcanized and adhered to the end surface on the small diameter side, while the coupling member 20 having a cylindrical shape is vulcanized and adhered to the outer peripheral surface of the end portion on the large diameter side. It is formed as a sulfur molded product.

Further, a seal fitting 22 is attached to the main rubber elastic body 14 from the large diameter side.
The seal fitting 22 has a thin, generally bottomed cylindrical shape as a whole. Further, an opening window 28 is provided on the bottom portion thereof, and a diaphragm 30 as a flexible film is provided so as to cover the opening window 28 in a fluid-tight manner.
It is fixed integrally.

The tubular portion of the seal fitting 22 has a stepped cylindrical shape consisting of a small diameter portion 24 on the bottom side and a large diameter portion 26 on the opening side. Furthermore, on the inner peripheral surfaces of the small diameter portion 24 and the large diameter portion 26, respectively, over substantially the entire surface,
The thin seal rubber layers 32 and 34 are integrally provided. In this embodiment, the seal rubber layer 32 provided on the inner peripheral surface of the small diameter portion 24 is formed integrally with the diaphragm 30.

The seal fitting 22 as described above is attached to the main rubber elastic body 14 by being externally fitted and fitted to the connecting fitting 20 at the large diameter portion 26. Further, a second mounting member 12 having a stepped cylindrical shape with a step substantially corresponding to the sealing member 22 is externally inserted outside the sealing member 22 to cover the outer peripheral surface of the sealing member 22. It is assembled in this way. Then, since the opening peripheral edge portion of the second mounting member 12 is caulked and fixed to the axial end surface of the connecting member 20, the sealing member 22 is fixed to the connecting member 20 in a fixed manner. It is assembled.

As a result, the opening of the seal fitting 22 is fluid-tightly covered by the main rubber elastic body 14. Further, the main rubber elastic body 14 of the seal fitting 22 is
The assembly is performed in a fluid, so that a fluid chamber formed by sealing a predetermined incompressible fluid is formed inside the seal fitting 22. The enclosed fluid is usually water, alkylene glycol,
Polyalkylene glycol, silicone oil and the like can be preferably used.

Further, inside the seal fitting 22, a partition member 36 having a substantially thick disk shape as a whole is provided.
However, in the small diameter portion 24, they are fixedly housed and arranged. The partition member 36 divides the fluid chamber into two parts in a fluid-tight manner, so that a part of the wall portion is constituted by the main rubber elastic body 14 and the internal pressure fluctuation is induced at the time of vibration input. And the equilibrium chamber 40 in which a part of the wall portion is constituted by the diaphragm 30 and the volume change is allowed based on the deformation of the first diaphragm 30.

Here, the partition member 36 is formed by combining the first divided body 42, the second divided body 44, and the third divided body 46 with each other as shown in FIG. ,It is configured. The first divided body 42 has a substantially cylindrical shape, and one end portion (upper end portion in the drawing) in the axial direction of the first divided body 42 has a support portion protruding outward in the radial direction in the shape of an outer flange. 48 and a sandwiching portion 50 projecting radially inward in the shape of an inner flange are integrally provided.

The second divided body 44 has a substantially annular shape, and is inserted and arranged in the inner hole 52 of the first divided body 42. Further, prior to the insertion of the second divided body 44, a disc-shaped first rubber plate 54 is inserted into the inner hole 52 of the first divided body 42, and the outer peripheral edge portion thereof is Clamping portion 50 of first divided body 42 and second divided body 44
It is supported by being sandwiched between. That is, thereby, the opening of the inner hole 52 of the first divided body 42 on the pressure receiving chamber 38 side is fluid-tightly closed by the first rubber plate 54.

Furthermore, the third divided body 46 has a substantially annular plate shape, and one end portion in the axial direction (lower end portion in the drawing) of the third divided body 46 is directed radially inward. And a constriction piece 62 projecting in the shape of an inner flange is integrally provided, and a constriction passage 64 is formed in the opening. Then, the third divided body 46 is inserted into the inner hole 52 of the first divided body 42, and is disposed below the second divided body 44. Further, prior to the insertion of the third divided body 46, the disc-shaped second rubber plate 56 is inserted into the inner hole 52 of the first divided body 42, and the outer peripheral edge portion thereof is It is supported by being sandwiched between the second divided body 44 and the third divided body 46. That is, as a result, the opening of the inner hole 52 of the first divided body 42 on the equilibrium chamber 40 side is
The second rubber plate 56 is fluid-tightly closed.

Here, the second rubber plate 56 is set to have a higher rigidity with respect to the change in volume than the first rubber plate 54. That is, in this embodiment, the second rubber plate 56 is formed to have a circular flat shape with a smaller diameter than the first rubber plate 54, so that the outer peripheral edge portion is sandwiched by the partition member 36. When the central portion of the second rubber plate 56 is pressed to generate a predetermined amount of volume change, that is, the amount of depression, the second rubber plate 56 has a larger force than the first rubber plate 54 ( It is set so that (force per unit area) is required.

In the partition member 36 having such a structure, the support portion 48 of the first divided body 42 is sandwiched between the step portion of the seal fitting 22 and the main rubber elastic body 14. The axially lower end surface of the first divided body 42 is fixedly assembled in the small-diameter portion 24 of the seal fitting 22 while being brought into contact with the bottom surface of the seal fitting 22.

Then, under such an assembled condition, in the partition member 36, the first, second, and third divided bodies 4 are
A through hole 58 extending across the pressure receiving chamber 38 and the equilibrium chamber 40 is formed by the inner holes of 2, 44, and 46, and the opening of the through hole 58 on the pressure receiving chamber 38 side is the first. The one rubber plate 54 covers the opening on the equilibrium chamber 40 side in a fluid-tight manner by the second rubber plate 56. Further, as a result, in the through hole 58,
Between the first rubber plate 54 and the second rubber plate 56,
An intermediate chamber 60 is formed.

Further, on the outer peripheral surface of the first divided body 42, there is provided a first concave groove 66 which opens in the outer peripheral surface and extends spirally in a circumferential direction for a length of at least one round. The outer peripheral surface opening of the first concave groove 66 is covered with the seal fitting 22 so that the pressure receiving chamber 38 and the equilibrium chamber 40 are communicated with each other, and the space between the two chambers 38, 40 is increased. A first orifice passage 68 is formed to allow the fluid flow.

Further, on the outer peripheral surfaces of the second divided body 44 and the third divided body 46, there is provided a second concave groove 70 which is open to the outer peripheral surface and extends in the circumferential direction with a length of less than one round in the circumferential direction. However, it is provided so as to straddle between the two divided bodies 44 and 46. Then, the outer peripheral surface opening of the second groove 70 is covered with the first divided body 42, so that the intermediate chamber 60 is communicated with the equilibrium chamber 40 and the space between the two chambers 60, 40 is increased. A second orifice passage 72 is formed to allow the fluid flow.

Here, since the second orifice passage 72 has a larger cross-sectional area / length ratio than the first orifice passage 68, the second orifice passage 72 is larger than the first orifice passage 68. It is tuned to a high frequency range. Specifically, in the present embodiment, the first orifice passage 68 is highly damped to the input vibration of low frequency and large amplitude around 10 Hz corresponding to shake or the like, based on the resonance action of the fluid that is made to flow therein. In order to exert the effect, the second orifice passage 72 has a low level against the input vibration of the medium-frequency amplitude of about 25 Hz, which corresponds to idling vibration, etc., based on the resonance action of the fluid flowing inside the second orifice passage 72. So that the dynamic spring effect is demonstrated,
Each is tuned.

That is, in the engine mount having such a structure, when vibration is input between the first mounting member 10 and the second mounting member 12 when mounted on a vehicle, An internal pressure fluctuation is caused in the pressure receiving chamber 38, and a fluid flow between the pressure receiving chamber 38 and the equilibrium chamber 40 through the first orifice passage 68 and a first deformation caused by elastic deformation of the first rubber plate 54. The flow of fluid through the second orifice passage 72 or the flow of fluid through the through hole 58 due to the elastic deformation of the first and second rubber plates 54 and 56 is generated, and The vibration isolation effect against the input vibration can be exhibited based on the flow action or resonance action of those fluids.

More specifically, first, when a low frequency large amplitude vibration such as a shake of about 10 Hz is input, the pressure receiving chamber 3
Since the internal pressure fluctuation caused by 8 is large and cannot be absorbed by the elastic deformation of the first rubber plate 54, the pressure receiving chamber 3
On the basis of the internal pressure fluctuation caused by 8, the fluid flow through the first orifice passage 68 is effectively generated between the pressure receiving chamber 38 and the equilibrium chamber 40.

Therefore, at the time of input of low frequency large amplitude vibration,
As shown in the test results in FIG. 3, the high damping effect can be effectively exerted based on the resonance action of the fluid made to flow through the first orifice passage 68.

Next, for such an engine mount,
When a medium-frequency amplitude vibration such as an idling vibration of about 25 Hz is input, the flow resistance of the first orifice passage 68 significantly increases and becomes a substantially closed state, but it is caused in the pressure receiving chamber 38. Since the fluctuation of the internal pressure is relatively small, the fluctuation of the internal pressure of the pressure receiving chamber 38 is absorbed by the elastic deformation of the first rubber plate 54 and reaches the intermediate chamber 60. However, the equilibrium chamber 40 in the intermediate chamber 60
As described above, the second rubber plate 56 arranged in the opening on the side has a higher rigidity with respect to the volume change than the first rubber plate 54, and therefore cannot absorb the internal pressure fluctuation exerted on the intermediate chamber 60. .. Therefore, based on the fluctuation of the internal pressure applied to the intermediate chamber 60, the fluid flow through the second orifice passage 72 is effectively generated between the intermediate chamber 60 and the equilibrium chamber 40. ..

Therefore, at the time of inputting the medium-frequency and amplitude vibrations,
As shown by the test results in FIG. 4, the low dynamic spring effect can be effectively exhibited based on the resonance action of the fluid that is caused to flow through the second orifice passage 72.

Further, when a high-frequency small-amplitude vibration corresponding to a muffled noise of about 100 Hz is input to such an engine mount, the flow resistance of the second orifice passage 72 is also remarkably increased, and substantially. It will be in a blocked state,
Since the internal pressure fluctuation caused by the pressure receiving chamber 38 and exerted on the intermediate chamber 60 becomes smaller, the internal pressure variation exerted on the intermediate chamber 60 by the elastic deformation of the first rubber plate 54 becomes:
It is absorbed by the elastic deformation of the second rubber plate 56 and released to the equilibrium chamber 40.

Therefore, when a high frequency small amplitude vibration is input,
As shown in the test results in FIG. 4, the first rubber plate 54
On the basis of the elastic deformation of the second rubber plate 56, the flow of the fluid through the through hole 58 of the partition member 36 is substantially allowed between the pressure receiving chamber 38 and the equilibrium chamber 40. As a result, the rise in the internal pressure of the pressure receiving chamber 38 can be effectively reduced or eliminated, so that a significantly high dynamic spring can be avoided and a good vibration damping effect can be exhibited.

In particular, in this embodiment, the through hole 58
A narrow passage 64 is formed in the opening on the side of the equilibrium chamber 40, and when a high-frequency small-amplitude vibration is input, the flow of the fluid through the narrow passage 64 is generated. By appropriately tuning the cross-sectional area / length of 64, it is possible to effectively utilize the excellent low dynamic spring effect exerted based on the resonance action of the fluid.

Further, in the engine mount having the above-mentioned structure, the first rubber plate 54 and the second rubber plate 56 are both pressure receiving chambers 38 and Since the volume of the intermediate chamber 60 can be changed and the substantial flow of the fluid through the through hole 58 can be permitted, the fluid flow based on the displacement of the movable plate, as disclosed in the above publications, etc. It is possible to set the mass component during the flow of the fluid to be smaller than that of the structure that allows the flow. Therefore, there is also an advantage that the internal pressure fluctuation caused by the vibration input in the high frequency range of 100 Hz or more can be sufficiently followed, and the desired vibration damping effect can be obtained more effectively. Is doing.

Although one embodiment of the present invention has been described in detail above, this is a literal example, and the present invention should not be construed as being limited to such a specific example.

For example, as the first rubber plate 54 and the second rubber plate 56, ones having the same radial dimension and different rigidity with respect to volume change depending on the material, thickness, etc. may be adopted. It is possible.

The specific structure, cross-sectional area, length, etc. of the first orifice passage 68 and the second orifice passage 72 are as follows.
Depending on the anti-vibration characteristics required for the mounting device,
It should be changed appropriately and is not limited to the examples.

In addition, in the above-mentioned embodiment, a specific example of the present invention applied to an engine mount for an automobile is shown. However, the present invention is not limited to this, and various other body mounts for automobiles, or various devices other than automobiles. It can be advantageously applied to a mounting device.

Although not listed one by one, the present invention is
Based on the knowledge of those skilled in the art, it can be implemented in various modified, modified, and improved modes, and
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[0043]

As is apparent from the above description, in the fluid-filled mount device having the structure according to the present invention, the fluid flow path between the pressure receiving chamber and the equilibrium chamber, which is generated when the vibration is input, is provided. The first rubber elastic plate and the second rubber elastic plate are switched according to the input vibration.

As a result, for the input vibration in the low frequency range, the vibration damping effect based on the resonance action of the fluid made to flow through the first orifice passage is obtained, and for the input vibration in the medium frequency range. , The vibration damping effect based on the resonance action of the fluid flowing through the second orifice passage, and the vibration damping effect based on the resonance action or the flow action of the fluid flowing through the through hole with respect to the input vibration in the higher frequency range. The shaking effect can be exerted respectively,
As a result, as a whole, it is possible to obtain a good anti-vibration effect that is exerted based on the flow action of the fluid against the input vibration in a wide frequency range.

[Brief description of drawings]

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

2 is an exploded view showing a partition member that constitutes the engine mount shown in FIG. 1. FIG.

FIG. 3 is a graph showing measurement results of vibration isolation performance of the engine mount shown in FIG. 1 against low frequency vibration.

FIG. 4 is a graph showing the results of measuring the vibration isolation performance against middle or high frequency vibration of the engine mount shown in FIG. 1.

[Explanation of symbols]

 10 1st attachment metal fittings 12 2nd attachment metal fittings 14 Main rubber elastic body 22 Seal metal fittings 30 Diaphragm 36 Partition member 38 Pressure receiving chamber 40 Equilibrium chamber 42 First division body 44 Second division body 46 Third division body 54 First rubber plate 56 Second rubber plate 58 Through hole 60 Intermediate chamber 72 Second orifice passage

Claims (1)

[Claims] Claim: What is claimed is: 1. A first mounting member and a second mounting member, which are arranged at a predetermined distance from each other, are connected by a rubber elastic body, and a partition member supported by the second mounting member is provided. A pressure receiving chamber, in which a predetermined incompressible fluid is enclosed inside, on both sides of the sandwiched portion, a part of the wall portion of which is constituted by the rubber elastic body and which causes an internal pressure fluctuation at the time of vibration input, and a wall portion In a fluid-filled mount device, a part of which is formed of a flexible film to form an equilibrium chamber having a variable volume, and a first orifice passage which connects the pressure receiving chamber and the equilibrium chamber to each other is provided. The partition member is provided with a through hole extending across the pressure receiving chamber and the equilibrium chamber, and a first rubber is provided on the pressure receiving chamber side and the equilibrium chamber side in the through hole. The elastic plate and the first rubber elastic plate are more rigid than the elastic plate against changes in volume. By arranging the second rubber elastic plates having a large size at a predetermined distance from each other, and by fixing each outer peripheral edge portion by such a partition member, the first rubber elastic plate and the second rubber elastic plate While forming an intermediate chamber with the rubber elastic plate,
A fluid-filled mount device characterized in that a second orifice passage having a larger cross-sectional area / length ratio than the first orifice passage is provided between the intermediate chamber and the equilibrium chamber.