JPH04131538A - High viscous fluid sealing type mount device - Google Patents

Abstract

PURPOSE:To keep a vibration insulating property and a damping property with respect to both a high frequency and a low frequency by interposing a fluid chamber between a first and second support fittings, and providing a displaceable narrow member in the second support fitting to make variable a narrow portion formed between the first and second support fittings. CONSTITUTION:A rubber elastic body 14 is interposed between first and second support fittings 10, 12. A fluid chamber 42 with high viscous fluid sealed therein is formed, and a plate 26 is disposed. A solenoid 46 is contained in an air chamber 44. and a narrow portion 52 is formed by a narrow fitting 50. When the solenoid 46 is energized and a plunger 48 is attracted, the narrow portion 52 is enlarged. Under an unenergized condition, effective slide shear force acts so as to exhibit damping force effectively. Meanwhile, under an energized condition, an increase in spring constant can be restrained, thereby exhibiting an effective insulating property.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a high-viscosity fluid-filled mount device that obtains a vibration damping effect based on the flow of a high-viscosity fluid sealed inside, and particularly relates to a high-viscosity fluid-filled mount device that obtains a vibration damping effect based on the flow of a high-viscosity fluid sealed therein. The present invention relates to a highly viscous fluid-filled mount device that can switch the mount's vibration isolation characteristics according to the conditions.

(Background Art) Conventionally, vibration transmission systems have been interposed between members that constitute vibration transmission systems.
As a type of vibration isolating device that connects these two members in vibration isolation, a first support metal fitting and a second support metal fitting are arranged facing each other with a predetermined distance apart in the vibration input direction, and a first support metal fitting and a second support metal fitting are interposed between them. BACKGROUND ART Mounting devices having a structure in which they are connected using rubber elastic bodies are known, and have been suitably used, for example, as engine mounts and differential mounts for automobiles.

By the way, in the past, in mounting devices with this type of structure, the vibration-proofing effect was achieved exclusively by the elasticity of the rubber elastic body, but in recent years, noise, vibration, and handling stability in automobiles have been improved. As the required characteristics for such things become more sophisticated, it is becoming difficult to meet the requirements with such structures, and for this reason, attempts are currently being made to improve the vibration isolation characteristics of mounting devices by sealing fluid within the device. It is being

As one aspect of such fluid encapsulation, the applicant of the present application has previously disclosed in Japanese Patent Application Laid-Open No. 62-288742, etc., a first support metal fitting and a second support metal fitting connected by a rubber elastic body. A fluid chamber filled and sealed with a highly viscous fluid is formed between the fluid chamber and a narrow portion of a predetermined gap in which shear stress is induced on the sealed fluid when vibration is input. We proposed a highly viscous fluid-filled mounting device with the following structure.

In other words, in a highly viscous fluid-filled mounting device with such a structure, the vibration damping force required for vibration isolation mainly in the low frequency range, such as shaking and bounce, can be
This can advantageously be achieved on the basis of the shearing action of the highly viscous fluid that occurs upon vibration input. In addition, in such a mount device, it is possible to tune the vibration damping force of the mount by adjusting the gap in the constriction that causes shear stress to high viscosity fluid, and the gap in the constriction can be adjusted. The smaller it is, the greater the vibration damping force will be exerted.

However, upon further study by the present inventors regarding such a highly viscous fluid-filled mount device, we found that in such a mount device, in order to improve the vibration damping force of the mount, the gap between the narrowed portions It has become clear that if the mount dynamic spring constant is made smaller, the mount dynamic spring constant increases accordingly, and that there is an inherent problem in that the mount dynamic spring constant increases significantly, especially in high frequency ranges. In addition to obtaining a larger vibration damping force for isolating vibrations in the low frequency range, there was still room for improvement in terms of vibration isolation performance against vibrations in the high frequency range, which corresponds to muffled sounds.

(Problem to be solved) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problem to be solved is:
The improved mount vibration damping characteristics can be switched depending on the input vibration, etc., thereby effectively achieving both vibration damping performance against low frequency vibrations and vibration isolation performance against high frequency vibrations. An object of the present invention is to provide a highly viscous fluid-filled mounting device.

(Solution Means) In order to solve this problem, the present invention provides:
A first support metal fitting and a second support metal fitting attached to each one of the members to be vibration-proof and connected are connected to each other by a rubber elastic body interposed between them. A fluid chamber filled with a highly viscous fluid is formed between the first support metal fitting and the second support metal fitting, and a constriction member protrudes from the second support metal fitting side to the first support metal fitting side. In the installation LJ, a constriction that spreads with a predetermined gap in a direction substantially perpendicular to the direction of vibration force, which causes shear stress to the high viscosity fluid when vibration is input, is formed between the constriction member and the first support metal fitting side. In the highly viscous fluid-filled mounting device, the constriction member is formed with a
The gap between the narrowing portions is made variable by supporting the second support fitting so as to be displaceable in the vibration input direction and by providing a driving means for displacing the narrowing member in the vibration input direction. This is a characteristic feature.

(Operations/Effects) That is, in the highly viscous fluid-filled mount device configured according to the present invention, by displacing the constriction member in the vibration input direction, the constriction member can be moved to the first support metal fitting. The sides are moved closer to each other/separated from each other, thereby changing the gap in the stenosis.

When the constriction member is brought closer to the first support metal fitting to reduce the gap in the constriction, a large damping force is advantageous based on the shearing action of the high viscosity fluid within the constriction. On the other hand, when the narrowing member is separated from the first support fitting side and the gap between the narrowing parts is increased, the mount dynamic spring constant can be advantageously suppressed.

Therefore, in the high viscosity fluid-filled mounting device according to the present invention, by displacing the constriction member in response to input vibration etc., the vibration isolation characteristics can be switched. Both vibration damping performance against high-frequency vibrations and vibration isolation performance against high-frequency vibrations can be obtained extremely effectively and selectively.

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

First, FIG. 1 shows an embodiment in which the present invention is applied to an automobile engine mount. In this figure, 10 and 12 are a first support metal fitting and a second support metal fitting, which are arranged facing each other at a predetermined distance, and are supported by a rubber elastic body 14 interposed between them. , are integrally and elastically connected to each other. In this engine mount 16, the first support metal fitting 10 and the second support metal fitting 12 are respectively attached to one of the engine unit side and the vehicle body frame side (not shown), so that the engine The engine unit is interposed between the unit and the vehicle body frame, so that the engine unit is supported against vibrations with respect to the vehicle body frame. Note that under such mounting conditions, the engine mount 16
When the engine unit load is applied to the first support fitting 10 and the second support fitting 12 in the opposing direction (in the vertical direction in FIG. 1), the side skin holding fittings 10 and 12 approach each other. At the same time, the main vibration to be damped is input to the opposite direction of the image support fittings 10 and 12.

More specifically, the first support fitting 10 is formed to have a substantially truncated conical shape. Further, a support portion 20 is formed on the small diameter side portion of the second support fitting 10, and extends integrally with a predetermined length in the axial direction, while a support portion 20 that projects in the axial direction is formed on the large diameter side end surface of the support portion 20. A first mounting bolt 18 is integrally provided, and the first mounting bolt 18 allows the first supporting metal fitting 10 to be mounted to the engine unit side or the vehicle body frame side. It has become.

Furthermore, the support portion 20 in the first support fitting 10
A thin cylindrical caulking part 24 coaxially extending from the support part 20 is integrally provided at the tip of the support part 20 . Then, the plate 26 having a substantially annular plate shape is fitted onto the second caulking portion 24 and fixed by caulking, so that the plate 26 expands in the direction perpendicular to the axis relative to the first support fitting 10. , are integrally attached. Note that the outer peripheral edge of the plate 26 is coated so as to cover its surface.
Covering rubber 28 of a predetermined thickness is vulcanized and bonded = On the other hand, the second support metal fitting 12 is a cylindrical metal fitting 32 that has a substantially cylindrical shape and has a caulked part 30 at the periphery of one opening in the axial direction.
and a bottom metal fitting 36 having a substantially thick disk shape. Then, with respect to the outer peripheral edge of the bottom metal fitting 36,
The caulking portion 30 of the cylindrical metal fitting 32 is fluid-tightly caulked and integrated, so that one opening of the cylindrical metal fitting 32 is covered with the bottom metal fitting 36, and the overall shape has a substantially bottomed cylindrical shape. It is formed.

The axial end of the cylindrical fitting 32 on the side where the caulking portion 30 is not provided is a tapered cylindrical portion 38 that gradually increases in diameter over a predetermined length as it goes toward the opening side. Further, a second mounting bolt 40 that projects outward in the axial direction is integrally provided on the bottom metal fitting 36, and the second mounting bolt 40 allows the second support metal fitting 12 to be attached to the vehicle body frame side. Alternatively, it can be attached to the engine unit side.

The second support metal fitting 12 is positioned opposite to the first support metal lO at a predetermined distance, with an opening toward the small-diameter end surface of the second support metal fitting 10. Under this condition, the first support metal fitting 10 and the second support metal fitting 12 are connected to each other by the rubber elastic body 14.

The rubber elastic body 14 has a substantially hollow truncated conical shape or a thick-walled Taper cylinder shape, and its inner circumferential surface faces the outer circumferential surface of the first support fitting 10 and its outer circumferential surface. are vulcanized and bonded to the inner circumferential surface of the tapered cylindrical portion 38 of the cylindrical metal fitting 32 constituting the second support metal fitting 12, whereby the first support metal fitting 10 and the second support metal fitting It is interposed between 12 and 12. By connecting the first support fitting 10 and the second support fitting 12 with this rubber elastic body 14, the opening of the second support fitting 12 is covered in a fluid-tight manner.

Furthermore, a rubber elastic member 1i34 having a substantially bottomed cylindrical shape is accommodated inside the second support fitting 12, and its outer peripheral edge is connected to the bottom fitting 36 by the caulking portion 30 of the cylindrical fitting 32. They are attached by being fluid-tightly sandwiched between them. The rubber elastic membrane 34 allows the inside of the second support fitting 12 to be connected to the first support fitting 10.
It is partitioned into a side and a bottom metal fitting 36 side, and is fluid-tightly divided.

In the second support fitting 12, the side closer to the first support fitting 10 than the rubber elastic membrane 34 is filled with a viscous fluid to form a sealed fluid chamber 42. Also, in the fluid chamber 42, a first support fitting 10 is provided.
The support part 20 is positioned so as to protrude from the support part 20, and the plate 26 attached to the tip of the support part 20 is positioned so as to expand in a direction substantially perpendicular to the vibration input direction.

Note that the specific viscosity of the high viscosity fluid sealed in the fluid chamber 42 is determined as appropriate depending on the vibration damping characteristics required of the mount, but generally, the viscosity is 5 Pa-sec to 500 Pa-5 ec, more preferably 10 Pa-sec to 200 Pa-5 eC, and for example, silicone oil or the like is suitably used.

On the other hand, in the second support metal fitting 2, the side closer to the bottom metal fitting 36 than the rubber elastic membrane 34 is an air chamber 44 that is sealed or communicated with the outside, and the volume of the air chamber 44 is variable. Based on this, deformation of the rubber elastic membrane 34 can be easily tolerated.

Further, a solenoid 46 is housed inside the air chamber 44, and a plunger 48 of the solenoid 46 is housed inside the air chamber 44.
is movable in the vibration input direction, and the bottom metal fitting 3
It is attached and fixed to 6. Furthermore, the solenoid 4
A disk-shaped constriction fitting 50 that spreads in the direction perpendicular to the axis is integrally fixed to the protruding end of the first ten examples of the first support fittings in the plunger 4 of No. 6, and the constriction fitting 50 is , is fixed to the bottom wall portion of the rubber elastic membrane 34.

When the solenoid 46 is not energized, the plunger 48 is positioned to protrude from the bottom metal fitting 36 side toward the first support metal fitting 10 side by the biasing force of the disc spring 54. When energized, the plunger 48 is attracted and displaced a predetermined distance toward the bottom metal fitting 36.

Furthermore, fixed to the protruding end of this plunger 48,
A constriction fitting 50 having a rubber elastic membrane 34 adhered to its surface is opposed to the plate 26 located within the fluid chamber 42 at a predetermined distance in the vibration input direction.

Accordingly, the constriction fitting 50 and the plate 26
A constricted portion 52 is formed between the constricted portion 52 and the constricted portion 52, which extends with a predetermined gap in a direction substantially perpendicular to the direction of vibration input, and causes shear stress to be applied to the high viscosity fluid present at the time of vibration input.

In addition, in such a constriction part 52, the energization to the solenoid 46 is controlled to control the constriction fitting 5.
0 in the direction toward/away from the plate 26, the gap can be changed as appropriate.

As is clear from the above description, in the engine mount 16 of this embodiment, the plunger 48 of the solenoid 46 and the constriction metal fitting 50 fixed to the protruding end portion of the first support metal fitting 10 A constriction member is configured to be displaceably supported by the second support fitting 12 and to form a constriction portion between it and the plate 26 provided on the side, and also exerts a driving force on the plunger 48. The leaf spring 54 and the solenoid 46 constitute a driving means for displacing the constriction member in the vibration input direction.

Then, engine mount 1 with this structure
As mentioned above, the engine mount 16 is mounted between the engine unit and the vehicle body frame. The shared load of the engine unit is applied between the support metal fitting 10 and the second support metal fitting 12, and the first support metal fitting 10 and the second support metal fitting 12 are brought closer to each other by a predetermined dimension. By the fluid chamber 4
2, a narrowed portion 52 is formed with a predetermined gap l between the facing surfaces of the plate 26 provided on the first support fitting lO side and the narrowed fitting 50 supported on the second support fitting 12 side. It is formed.

When vibration is input between the first support metal fitting 10 and the second support metal fitting 12 under such a mounting condition, the side skin holding metal fittings 10 and 12 are relatively displaced. Accordingly, the distance between the plate 26 and the constriction fitting 50 changes, causing the high viscosity fluid present in the constriction part 52 to flow back and forth in a direction approximately perpendicular to the vibration input direction, thereby reducing the height. A shear shear stress is generated in the viscous fluid, and a damping force against input vibration is exerted based on the shear shear stress.

In addition, in the narrowed portion 52, the gap: l is controlled by controlling the energization to the solenoid 46 while the mount is attached to move the narrowing fitting 50 toward/away from the plate 26. However, in the figure,
11! 2, and depending on the size of the gap between the narrowed portions 52, the shear stress exerted by the flow of the highly viscous fluid existing therein, and the vibration damping properties of the mount. will be forced to change.

In other words, without energizing the solenoid 46,
When the plunger 48 is projected toward the first support fitting 10, the narrowed portion 52 is formed with a small genital area β1, as shown by the solid line in FIG. More effective shear stress is induced on the highly viscous fluid existing within the constriction 52, and thus,
This means that an effective damping force against input vibration can be exerted.

On the other hand, when the solenoid 46 is energized and the plunger 48 is attracted toward the bottom metal fitting 36, the narrowed portion 52 opens with a large gap 12, as shown by the imaginary line in FIG. Although the highly viscous fluid present within the constriction 52 does not create an effective shear shear stress, an increase in the mount dynamic spring constant due to the inclusion of the highly viscous fluid is advantageous. suppressed,
Therefore, an effective insulation effect against input vibration can be exhibited.

Therefore, according to such an engine mount 16, excellent vibration damping against low frequency vibrations can be achieved by switching and controlling the energization to the solenoid 46 and changing the gap between the narrowed portions 52 according to the running condition of the vehicle. performance and excellent vibration isolation performance against high-frequency vibrations can both be effectively and selectively exhibited.

In addition, in the engine mount 16 of this embodiment, when the engine mount 16 is mounted, the increase in fluid pressure in the fluid chamber 42 caused by the weight of the engine unit is caused by sandwiching the rubber elastic membrane 34 and causing the fluid to increase. Based on the volume variability of the air chamber 44 formed on the opposite side of the chamber 42, the spring characteristics of the rubber elastic body 14 and the high viscosity fluid sealed in the fluid chamber 42 can be effectively absorbed and reduced. The damping characteristics due to the shearing action of the fluid chamber 42 can be effectively and stably exhibited without being harmed by such an increase in internal pressure within the fluid chamber 42, and the desired mount It also has the advantage of being able to advantageously obtain anti-vibration characteristics.

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

For example, in the embodiment described above, the constriction fitting 50 is moved toward/away from the plate 26 in response to input vibration, etc.
By selectively switching the gap between the narrowed portions 520 into two types, large and small, the mount vibration isolation characteristics can be selectively switched between high damping characteristics and low dynamic spring characteristics. It is also possible to change the mount vibration isolation characteristics by selectively switching the gap between portions 520 to three or more different sizes.

Furthermore, the control mode for the displacement of the constriction fitting 50 is not limited to the example shown, and for example, the phase of vibration input to the mount is detected by a piezoelectric element or the like, and the control mode is adjusted to correspond to the phase of the input vibration. and attach the constriction fitting 50 to the plate 5.
It is also possible to control its displacement so that it approaches/separates from 2. Then, such a constriction fitting 50,
By controlling the plate 52 to move toward and away from the plate 52 with a phase opposite to that of the input vibration and with the same period as the input vibration, the change in the gap between the narrowed part 52 and the accompanying change in the narrowed part 52 can be avoided. Since the flow of the high viscosity fluid can be generated more effectively, a large vibration damping force can be advantageously obtained based on the shearing action of the high viscosity fluid, and On the other hand, the constriction fitting 50 is brought close to the plate 52 with the same phase as the input vibration and with the same period as the input vibration.
By displacing the mount apart, a change in the gap between the narrowed portions 520 and the associated flow of high viscosity fluid within the narrowed portions 52 can be effectively reduced, so a low mount dynamic spring constant is advantageous. You can get it.

Furthermore, the drive means for displacing the constriction fitting 50 is not limited to the solenoid mechanism as illustrated, but may also include a drive mechanism that combines a motor and a feed mechanism, pneumatic pressure, hydraulic pressure, etc. Various known actuator mechanisms can be employed, such as a cylinder mechanism using PZT or a piezoelectric drive mechanism using piezoelectric materials such as PZT.

Further, in the engine mount 16 in the embodiment, an air chamber 44 is formed on the opposite side of the fluid chamber 42 with the rubber elastic membrane 34 in between. The pressure was supposed to be absorbed, but
Such an air chamber does not necessarily need to be provided.

Further, the structure of the constricted portion in the fluid chamber is not limited to that of the above embodiment, and when vibration is input,
Any material can be used as long as it can exert an effective shearing action on the high viscosity fluid. For example, by arranging the constriction member directly opposite the first support fitting, the constriction member It is also possible to form a narrowed portion between the surfaces facing one support metal fitting.

In addition, in the above embodiment, a specific example was shown in which the present invention was applied to an automobile engine mount, but the present invention is also applicable to automobile body mounts, differential mounts, etc., and various devices other than automobiles. Any of these can be advantageously applied to the mounting device in the.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. added based on the knowledge of those skilled in the art, and such embodiments may be incorporated into the present invention. It goes without saying that any of these methods are included within the scope of the present invention as long as they do not depart from the spirit of the invention.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a specific example of an engine mount having a structure according to the present invention. Further, FIG. 2 is a longitudinal cross-sectional view showing a state in which the engine mount shown in FIG. 1 is attached to a vehicle. 10: First support fitting 12: Second support fitting 14; Rubber elastic body 26: Plate 42: Fluid chamber 46: Solenoid 50: Constriction fitting 54: Belleville spring

Claims (1)

[Scope of Claims] A first support metal fitting and a second support metal fitting each attached to each one of the members to be vibration-isolated and connected, which are arranged at a predetermined distance from each other in the vibration input direction, They are connected to each other by a rubber elastic body interposed between them,
A fluid chamber filled with a highly viscous fluid is formed between the first support metal fitting and the second support metal fitting, and a constriction protrudes from the second support metal fitting side to the first support metal fitting side. A member is provided between the constriction member and the first support fitting side, and spreads with a predetermined gap in a direction substantially perpendicular to the direction of vibration input, which causes shear stress to the high viscosity fluid at the time of vibration input. In a highly viscous fluid-filled mounting device formed with a constriction, the constriction member is supported so as to be movable in the vibration input direction with respect to the second support fitting, and the constriction member is displaceable in the vibration input direction. A highly viscous fluid-filled mount device, characterized in that the gap between the narrowed portions is made variable by providing a drive means for causing the narrowed portion to move.