JP3116558B2 - Phase conversion type fluid filled type vibration damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a mount anti-vibration characteristic by generating an internal pressure in a fluid chamber formed therein and converting a phase of an internal pressure change induced in the fluid chamber when a vibration is input. And a phase change type fluid filled type vibration damping device.

[0002]

2. Description of the Related Art Conventionally, as a kind of a vibration isolator interposed between members constituting a vibration transmission system, a first support fitting and a first support fitting respectively attached to each one of vibration isolating connection or supported members. 2. Description of the Related Art A vibration isolator is known in which two support fittings are elastically connected to each other with a rubber elastic body interposed between the two support fittings, for example, as an automobile engine mount or a suspension bush. It has been used.

[0003] In recent years, as one method for realizing higher vibration isolation characteristics, a certain portion of a wall portion is formed of a rubber elastic body, and a predetermined portion is provided inside the vibration isolation device. While providing a fluid chamber in which the incompressible fluid is sealed, a part of the wall of the fluid chamber is constituted by a diaphragm supported so as to be displaceable with respect to the second support fitting,
An actuator is arranged behind such a diaphragm, and by vibrating the diaphragm, an internal pressure is generated in the fluid chamber,
There has been proposed a phase conversion type fluid filled type vibration damping device in which the mount vibration damping characteristics are controlled by changing the phase of the internal pressure change induced in the fluid chamber at the time of vibration input. For example, JP-A-59-1828 and JP-A-5-1828
Japanese Patent Application Laid-Open Nos. 9-1829, 60-60540, and Hei 3-73741 disclose such vibration isolators.

Incidentally, in such a vibration isolator, it is necessary to support the diaphragm so as to be displaceable with respect to the second support fitting. Therefore, conventionally, as described in the above-mentioned publication, A structure is adopted in which the diaphragm is connected to and supported by the second support via an elastic member such as a rubber plate, or is supported by the second support with a gap (play) of a predetermined dimension. I have.

However, in such a vibration isolator, since the diaphragm is displaceably disposed, when the frequency of the input vibration matches the natural frequency of the diaphragm, the diaphragm causes a resonance phenomenon. As a result, there is an inherent problem that the resonance phenomenon of the diaphragm causes an amplification action of the input vibration and the like, and the vibration-proof characteristics of the vibration-proof device are remarkably deteriorated. I was doing it.

[0006]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to solve a problem that a remarkable decrease in vibration isolation characteristics caused by a resonance phenomenon of a diaphragm is solved. It is an object of the present invention to provide a phase change type fluid filled type vibration damping device having an improved structure which can be reduced.

[0007]

A feature of the present invention is to solve the above-described problem by using a rubber elastic body interposed between a first support member and a second support member. While connecting, a fluid chamber in which a predetermined incompressible fluid is sealed, a part of the wall is provided by such a rubber elastic body, and a part of the wall of the fluid chamber is A phase conversion type fluid-filled protection device comprising a diaphragm supported so as to be displaceable with respect to a second support fitting, and an actuator for oscillating the diaphragm arranged behind the diaphragm. In the vibration device, a fluid flow path in which a fluid flow is generated at the time of vibration input is formed inside the fluid chamber, and a resonance frequency of the fluid caused to flow through the fluid flow path is defined as:
The tuning is performed in accordance with the natural vibration frequency of the diaphragm.

[0008]

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

First, FIG. 1 shows a tubular engine mount 10 for an automobile according to one embodiment of the present invention. The engine mount 10 has an inner cylindrical fitting 12 and an outer cylindrical fitting 14 arranged at a predetermined distance in the radial direction and eccentric by a predetermined amount, and is provided on a rubber elastic body 16 interposed therebetween. And a mount main body 18 that is configured to be elastically connected to each other, and the mount main body 18 has a structure integrally assembled with a bracket 20. And in such an engine mount 10, the mount body 1
8 is attached to one of the body side and the power unit side, and the outer cylinder fitting 14
Is attached to either the body side or the power unit side via the bracket 20, so that the power unit is supported on the body by vibration isolation.

In such a mounted state, in the mount main body 18, the rubber elastic body 16 is deformed by the weight of the power unit applied between the inner and outer cylindrical fittings 12, 14 so that the inner and outer cylindrical fittings 12, 14 are deformed. Are positioned substantially coaxially. Further, under such a mounted state, the eccentric direction of the inner and outer cylinder fittings 12 and 14 (FIG. 1)
The main vibration to be damped is input in the middle, up and down directions.

More specifically, the inner cylindrical fitting 12 has a thick cylindrical shape. In addition, a support fitting 22 and a stopper fitting 24 are provided at the axially central portion of the inner cylindrical fitting 12.
Are fixed by welding or the like, and are mounted so as to protrude at predetermined heights outward on both sides of the inner cylindrical metal fitting 12 in the radial direction.

Further, a metal sleeve 26 having a thin cylindrical shape is disposed radially outward of the inner cylindrical fitting 12 so as to be eccentric by a predetermined amount in the projecting direction of the support fitting 22 and the stopper fitting 24. A rubber elastic body 16 having a thick cylindrical shape as a whole is interposed between the inner cylindrical fitting 12 and the metal sleeve 26, and is vulcanized and adhered to the inner cylindrical fitting 12 and the metal sleeve 26. It is formed as an integrated vulcanized molded product.

The metal sleeve 26 is provided with a first window 28 and a second window 30 on both sides of the inner sleeve 12 which are opposed to each other with the eccentric direction interposed therebetween. Further, the rubber elastic body 16 has a first recess 32 which is opened to the outer peripheral surface through a first window portion 28 on both sides of the inner cylinder fitting 12 opposed to each other with the eccentric direction interposed therebetween, and a second window portion. A second recess 34 opening to the outer peripheral surface through 30 is provided.

Further, the first recess 32 has a support fitting 2.
In the second recess 34, the stopper fittings 24 are respectively positioned at a predetermined height from the bottom side. On the protruding end surface of the support bracket 22, a flat umbrella bracket 36 extending in a direction perpendicular to the protruding direction is fixed by caulking, and a cushion rubber 38 is provided on the outer surface of the umbrella bracket 36. Are fixed. A stopper rubber 4 having a predetermined thickness is provided on the protruding end surface of the stopper fitting 24.
0 is formed integrally with the rubber elastic body 16.

Further, the rubber elastic body 16 has a bottom wall portion that separates the first recess 32 and the second recess 34 from each other.
An orifice passage 42 extending along the inner peripheral surface of the metal sleeve 26 in a direction opposite to the first recess 32 and the second recess 34 and communicating the recesses 32 and 34 with each other.
Is provided.

In addition, the bottom wall portion has a lightening portion 4 penetrating in the axial direction on both sides of the inner cylinder fitting 12.
4, 44 are formed. And these lightening parts 4
4 and 44, the bottom wall of the second recess 34 is made thinner, thereby forming a flexible wall 46 that can be easily elastically deformed.

Thus, the outer tube fitting 14 is externally inserted into such an integrally vulcanized molded product, and is fitted and fixed to the metal sleeve 26. The outer tube fitting 14 covers the openings of the first recess 32 and the second recess 34.

As a result, the pressure receiving chamber 48 and the equilibrium chamber 50 each having a predetermined incompressible fluid sealed therein,
Is formed. The pressure receiving chamber 48 and the equilibrium chamber 50
Are communicated with each other by an orifice passage 42, and through the orifice passage 42,
The sealed fluid is allowed to flow between 8,50. In addition, water, alkylene glycol, polyalkylene glycol, silicone oil, and the like are generally used as the sealed fluid.

That is, in the pressure receiving chamber 48,
When vibration is input between the inner and outer cylindrical fittings 12 and 14, the internal pressure fluctuates due to the deformation of the rubber elastic body 16, and as is apparent from this, in the present embodiment, such a variation occurs. The pressure receiving chamber 48 forms a fluid chamber. On the other hand, in the equilibrium chamber 50, the flexible wall 46
The change in internal pressure is reduced or eliminated by easily permitting a change in volume based on the elastic deformation of. Therefore, at the time of vibration input, an internal pressure difference is generated between the pressure receiving chamber 48 and the equilibrium chamber 50, and both chambers 48, 50
Between them, the fluid flows through the orifice passage 42, and a predetermined vibration-proof effect is exerted on the basis of the resonance action of the fluid.

In this embodiment, in particular, the orifice passage 42 has a high damping effect against low-frequency, large-amplitude vibrations such as shakes based on the resonance action of the fluid flowing through the orifice passage 42. Length and cross-sectional area are set.

The mount body 18 having such a structure is assembled to the bracket 20 by being press-fitted and fixed into a circular mounting hole 54 provided in the bracket 20. . The bracket 20 is integrally provided with a mounting portion 56 that protrudes outward, and the mounting portion 56 is mounted and fixed to the body side or the power unit side.

Further, the bracket 20 is provided with a through hole 58 extending through the peripheral wall at a portion of the mount main body 18 mounted in the mounting hole 54 located outside the pressure receiving chamber 48. Also, this through hole 58
Outer tube fitting 1 of mount body 18 located at inner opening
4 is provided with a through hole 60, through which the through hole 58 communicates with the pressure receiving chamber 48 of the mount body 18.

On the other hand, the outside opening of the through hole 58 is enlarged in diameter by a predetermined dimension, and a diaphragm 62 having a substantially flat plate shape is disposed therein. A mounting ring 66 is mounted on the outer peripheral edge of the diaphragm 62 via a support rubber 64. The mounting ring 66
By being bolted to the bracket 20,
The diaphragm 62 is mounted on the bracket 20. That is, the vibration plate 62 is
It is attached so as to be displaceable based on the elastic deformation of the support rubber 64. The diaphragm 62 is formed of a non-magnetic material such as a synthetic resin or an aluminum alloy.

When the diaphragm 62 is mounted, the outer opening of the through hole 58 provided in the bracket 20 is covered in a fluid-tight manner, so that the inside of the through hole 58 is also covered with the pressure receiving chamber. 48 are formed.

A rubber sleeve 68 is inserted and disposed inside the through hole 58 formed in the bracket 20, and a substantially annular holding member 70 bolted to the bracket 20 and the outside of the mount body 18. It is pinched in the axial direction between the tube fitting 14. Thereby, the space between the through hole 60 provided in the outer tube fitting 14 and the through hole 58 provided in the bracket 20 is sealed in a fluid-tight manner.

Further, the vibration plate 62 is attached to the bracket 20.
, Electromagnetic driving means 72 as an actuator is mounted. The electromagnetic driving means 72 includes a circular block-shaped permanent magnet 74. The permanent magnet 74 is housed inside a lid 76 having an inverted cup shape. It is fixed in contact with the bottom center.

On the other end face of the permanent magnet 74 on the side of the other magnetic pole, an end fitting 80 having a substantially disc shape is disposed in contact with the end face. The outer diameter of the end fitting 80 is larger than that of the permanent magnet 74, and is projected from the permanent magnet 74 radially outward by a predetermined dimension.

Further, a substantially annular peripheral metal fitting 82 is provided in the opening of the lid metal fitting 76, and is superimposed on a flange 75 provided on the opening peripheral part of the lid metal fitting 76. Installed. Also, the inner diameter of the peripheral metal fitting 82 is smaller than the peripheral wall of the lid metal fitting 76,
The inner peripheral surface of the end fitting 8 is projected radially inward from the inner peripheral surface of the lid fitting 76 by a predetermined dimension.
It is opposed to the outer peripheral surface at a predetermined distance in the radial direction.

Each of the lid metal member 76, the end metal member 80, and the peripheral metal member 82 is formed of a ferromagnetic material such as iron. Thereby, around the permanent magnet 74,
An annular or cylindrical gap continuous in the circumferential direction is formed between the radially opposed surfaces of the end fittings 80 and the peripheral fittings 82 located on the magnetic path while a substantially closed magnetic path form of the magnetic path is formed. The part 86 is formed.

Further, an end fitting 8 for forming such a magnetic path.
A movable member 88 formed of a non-magnetic material such as synthetic resin or aluminum is disposed at a predetermined distance outward in the axial direction of 0. The movable member 88 has a substantially bottomed cylindrical shape as a whole, and has a cylindrical wall portion 90.
Are inserted and positioned in the gap portion 86 on the magnetic path. And, the cylindrical wall portion 90 of the movable member 88,
A small gap is formed between the movable member 8 and the facing surface forming the gap portion 86.
8 can be displaced in the axial direction.

A coil is wound around the outer peripheral surface of the cylindrical wall portion 90 of the movable member 88, and a movable coil 92 is formed thereon. As a result, the movable coil 92 and the movable member 88 can be integrally displaced within the gap portion 86.

The electromagnetic driving means 72 formed as described above has a flange 75 of a cover fitting 76 superimposed on the outer peripheral edge of the through hole 58 in the bracket 20 as shown in FIG. By being fixed, it is fixed to the bracket 20. Further, the movable member 88 of the electromagnetic driving means 72 is fixed on the back surface of the diaphragm 62 by bolts.

That is, in this embodiment, by applying an alternating current to the movable coil 92 in the electromagnetic drive means 72, an electromagnetic force (Lorentz force) is generated on the movable coil 92 in accordance with Fleming's left-hand rule. Thus, a driving force is exerted on the diaphragm 62 via the movable member 88 on which the movable coil 92 is mounted.

When the vibration plate 62 is driven, the internal pressure of the pressure receiving chamber 48 is changed.
The internal pressure of the mount 8 can be controlled, so that the anti-vibration characteristics of the mount can be appropriately changed. Specifically, for example, at the time of inputting low-frequency vibration, the diaphragm 62 is vibrated in the same phase as the input vibration to positively generate the internal pressure of the pressure receiving chamber 48, and to allow the fluid to flow through the orifice passage 42. By increasing the flow rate, it is possible to exhibit high damping characteristics.
By vibrating the diaphragm 62 in a phase opposite to the input vibration to absorb or reduce the internal pressure of the pressure receiving chamber 48, it is possible to exhibit low dynamic spring characteristics.

By the way, in the engine mount 10 of the present embodiment, the inside of the pressure receiving chamber 48 whose internal pressure is controlled by the vibration of the vibration plate 62 is controlled by the umbrella fitting 36 to form the umbrella. An annular stenosis flow which is substantially bisected into the inner side and the outer side of the metal fitting 36 and communicates the inner part and the outer part between the inner peripheral surface of the pressure receiving chamber 48 and the outer peripheral part of the umbrella fitting 36. A passage 94 is formed.

Accordingly, when vibration is input between the inner and outer cylindrical fittings 12 and 14, the umbrella fitting 36 is displaced in the pressure receiving chamber 48, so that the fluid flows through the constricted flow path 94. It is designed to be tightened.
In other words, the constricted flow path 94 constitutes one resonance system that uses a fluid that is vibrated at the time of vibration input and flows through the constricted flow path 94 as a mass component.

In the present embodiment, the resonance frequency of the fluid flowing through the constricted flow path is tuned in accordance with the natural vibration frequency of the diaphragm 62 elastically supported by the support rubber 64. . Specifically, at the time of vibration input of the vibration plate 62 in the natural vibration frequency range, such a narrow flow path effect can be exerted based on the resonance action of the fluid flowing through the narrow flow path 94 so that a low dynamic spring effect can be exhibited. The cross-sectional area and length of 94 are set.

Therefore, in the engine mount 10 having such a structure, amplifying action of the input vibration caused by the high dynamic spring caused by the increase of the internal pressure of the pressure receiving chamber 48 caused by the resonance phenomenon of the diaphragm 62. Can be reduced or eliminated based on the low dynamic spring effect exerted on the basis of the resonance action of the fluid caused to flow through the constricted flow path 94. Therefore, the resonance phenomenon of the diaphragm 62 This can effectively reduce or prevent the deterioration of the mount anti-vibration characteristics, and the desired anti-vibration characteristics can be advantageously and stably exhibited over a wide frequency range. .

FIG. 2 shows the results of a test conducted on the engine mount 10 having the above-described structure and measurement of the frequency characteristics of the vibration isolation performance. In this figure, as a comparative example having a conventional structure, the same test was performed on an engine mount having the same structure as the engine mount 10 except that the umbrella fitting 36 was not mounted. Are also shown.

As can be seen from these figures, in the engine mount 10 of the present embodiment, a remarkably high dynamic spring caused by the resonance phenomenon of the diaphragm 62 caused in the engine mount of the comparative example in a frequency range around 130 Hz. It is clearly recognized that the transformation can be eliminated very effectively.

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 these specific examples.

For example, in the above embodiment, a fluid flow path is formed by an annular narrow flow path 94 formed between the inner surface of the pressure receiving chamber 48 and the umbrella fitting 36 disposed in the pressure receiving chamber 48. However, such a fluid channel can be formed with a structure other than the illustrated structure. In particular,
In the above embodiment, by appropriately adjusting the cross-sectional area and the length of the through-hole 58 provided in the bracket 20, which constitutes a part of the pressure receiving chamber 48, the above-mentioned fluid flow path is formed by the through-hole 58. And so on.

Further, in the above embodiment, the equilibrium chamber 5 communicated with the pressure receiving chamber 48 through the orifice passage 42.
Although 0 is provided, the orifice passage 42 and the equilibrium chamber 50 are not necessarily provided.

Although the electromagnetic drive means 72 is used in the above embodiment as an actuator for exciting the diaphragm, an actuator other than the electromagnetic drive means such as an electrostrictive element may be used instead. Of course, it is possible.

Further, in the above-described embodiment, a specific example in which the present invention is applied to a cylindrical fluid-filled type vibration damping device is shown. It goes without saying that the present invention can be advantageously applied to various types of vibration isolators disclosed in the above-mentioned publications and the like.

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

[0047]

As is apparent from the above description, in the phase change type fluid-filled vibration damping device having the structure according to the present invention, the fluid that is caused to flow inside by the fluid flow path is used as the mass component. One vibration system is configured,
At the time of vibration input of the vibration plate in the natural vibration frequency range, a low dynamic spring of the mount anti-vibration characteristics is exhibited based on the resonance action of the fluid that is caused to flow through the fluid flow path.

Therefore, according to such a phase conversion type fluid filled type vibration damping device, a remarkable decrease in mount vibration damping characteristics due to the resonance phenomenon of the diaphragm can be reduced or eliminated. The desired vibration isolation characteristics based on the internal pressure control of the pressure receiving chamber by the driving (excitation) of the plate can be advantageously and stably exhibited over a wide frequency range.

[Brief description of the drawings]

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

FIG. 2 is a graph showing a result of measuring a frequency characteristic of an anti-vibration effect in an engine mount having a structure as shown in FIG. 1 together with a measurement result of a comparative example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 engine mount 12 inner cylinder 14 outer cylinder 16 rubber elastic body 18 mount body 20 bracket 36 umbrella bracket 48 pressure receiving chamber 62 diaphragm 64 supporting rubber 72 electromagnetic driving means 74 permanent magnet 86 gap portion 88 movable member 92 movable coil 94 narrowing Channel

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16F 13/26

Claims (1)

(57) [Claims] 1. A first support fitting and a second support fitting,
A fluid chamber in which a predetermined incompressible fluid is sealed inside with a rubber elastic body interposed between them,
A part of the wall portion is constituted by the rubber elastic body, and a part of the wall portion of the fluid chamber is constituted by a diaphragm supported so as to be displaceable with respect to the second support fitting. Along with
In a phase conversion type fluid-filled vibration damping device having an actuator for exciting the diaphragm disposed behind the diaphragm, a fluid flow in which a fluid flow is generated at the time of vibration input into the fluid chamber. A phase conversion type fluid filled type vibration damping device, wherein a resonance path of a fluid which forms a passage and is caused to flow through the fluid flow path is tuned in accordance with a natural vibration frequency of the diaphragm.