JPS63275827A - Vibrationproofing method using liquid sealing mounting device - Google Patents

Abstract

PURPOSE:To make it possible to exhibit good vibrationproofing effect for input vibration in high frequency band by making an acting member hold elastically against a holding body for making the acting member exhibit a damper action. CONSTITUTION:Natural frequency of a mass member 50, which is determined by a spring constant of a coil spring 48 and mass of the member 50 and the liquid in a clearance 52, is set in a higher frequency than a frequency set for the clearance 52. When frequency of input vibration becomes higher than the natural frequency of the mass member 50, buildup of fluid pressure in a chamber portion between 50 and a partition member 32 is suppressed by movement of the mass member 50 to the reverse direction. Accordingly, input vibration in high frequency band can be isolated favorably by damper action of the mass member 50 owing to resonance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a vibration isolation method using a fluid-filled mount device such as an automobile engine mount, and particularly relates to a vibration isolation method using a fluid-filled mount device such as an automobile engine mount. This invention relates to an anti-vibration method for achieving an anti-vibration effect.

(Prior art) In vibration systems in which vibration transmission is suppressed using a mounting device such as an automobile engine mount, there is generally a wide range of resistance to vibration input between two members connected via the mounting device. It is required to exhibit good vibration isolation effects in the frequency range. In addition, it is particularly required to exhibit a sufficient damping effect against large-amplitude vibrations in a low frequency range.

Therefore, in recent years, (a) first and second supports arranged to face each other in the vibration input direction;
(b) a rubber elastic body interposed between the first and second supports to elastically connect them; and (C) a rubber elastic body disposed on the second support and connected to the first support. (d) a predetermined incompressible fluid sealed in the fluid accommodation space; (e) a partition member that partitions the fluid accommodation space into a pressure receiving chamber on the first support side and an equilibrium chamber on the partition wall member side; (f) a throttle passage that allows the pressure receiving chamber and the equilibrium chamber to communicate with each other; g) a movable member disposed so as to be deformed or displaced by a predetermined amount in opposing directions in accordance with the fluid pressure difference within the pressure receiving chamber and the equilibrium chamber, and (h)
an actuating member protruding into the pressure receiving chamber from the first support in a state in which the pressure receiving chamber is interposed approximately two times between the chamber portion on the first support side and the chamber portion on the partition member side. By using a so-called fluid-filled mounting device and attaching the first and second supports of the fluid-filled mounting device to two members to which vibrations are transmitted, the incompressible fluid flows into the throttle passage. Based on the fact that the movable member is deformed or displaced, the vibration in the first frequency range of the vibration or motion that is manually applied between the two members is vibration in a second frequency range higher than the frequency range of the second frequency range based on the fact that an incompressible fluid flows through a gap formed between the actuating member and the inner wall of the pressure receiving chamber. It has been proposed to block or attenuate vibrations in a third frequency range higher than the above frequency range.

In this way, among the vibrations input between the two members connected via the mount device, human power in three different frequency ranges corresponding to the first, second and third frequency ranges can be applied. It can exhibit a good vibration damping effect against vibrations, and by setting the first frequency range to a low frequency, it can exhibit a sufficiently good damping effect against low frequency and large amplitude human vibrations. It is possible to do so.

(Problem) However, in the conventional vibration isolation method using such a fluid-filled mounting device, the vibration isolation effect against the input vibration in the third frequency range is limited to the operation of the mounting device, as is well known. This is obtained based on the liquid column resonance effect of the incompressible fluid flowing in the gap between the member and the wall of the pressure-receiving chamber, so when vibration is input in a frequency range higher than the third frequency range, , it becomes difficult for the incompressible fluid to flow through the gap, and as a result, the dynamic spring constant of the mounting device and, by extension, the vibration transmissibility increase significantly, resulting in a significant reduction in the vibration isolation function. there were.

For example, in automobile engine mounts, the 200 H
200 to 4001-1 z based on the fact that the incompressible fluid flows through the gap between the actuating member and the wall of the pressure-receiving chamber while attenuating or blocking input vibrations of about z or less.
Attenuation of input vibration in a frequency range of about 400 Hz (third frequency range) will be attempted, but in this case, it is inevitable that the vibration transmissibility will become significantly large in a frequency range of about 400 Hz or higher. It is.

Note that automotive engine mounts are usually 500H.
It is sufficient that the third frequency range is shifted to the high frequency side, as long as it exhibits a good vibration isolation effect against input vibrations of about z or below. If you use it to achieve a good vibration-proofing effect,
Even if the vibration transmissibility increases significantly in a frequency range higher than the third frequency range, this does not pose much of a problem;
There is a problem in that the vibration transmissibility increases significantly in the frequency range of about 00 Hz.

(Solution Means) The present invention has been made against the background of the above-mentioned circumstances, and its gist is to provide (a) first and second supports, and (b) rubber as described above. (c) an elastic body;
Using a fluid-filled mounting device comprising a partition wall member, (d) an incompressible fluid, (e) a partition member, (f) a throttle passage, (g) a movable member, and (h) an actuating member. When the first and second supports are respectively attached to two members to which vibrations are transmitted and the vibration transmission between the two members is suppressed, the actuating member of the fluid-filled mounting device is attached to the first member. By elastically supporting the support body through a predetermined elastic member, and by making the actuating member a mass member having a predetermined mass and causing the actuating member to exert a damper action, the non-compressible Based on the fluid flowing through the constriction passage, the input vibration in the first frequency range is
Furthermore, based on the deformation or displacement of the movable member, human vibration in a second frequency range higher than the first frequency range is damped or blocked, respectively, while the incompressible fluid is activated. Based on the flow through the gap formed between the member and the inner wall of the pressure-receiving chamber, input vibration in a third frequency range higher than the second frequency range is generated, and based on the damper action of the actuating member. Therefore, input vibrations in a fourth frequency range higher than the third frequency range are respectively attenuated or blocked.

(Operation/Effect) According to the method of the present invention, it is possible to exhibit good vibration isolation effects against human vibrations in the first, second, and third frequency ranges, which are different from each other, as with the conventional method. Based on the damper action of the actuating member, it is possible to exhibit a good vibration isolation effect even against human vibrations in the fourth frequency range, which is even higher than those, and therefore, it is possible to exhibit input vibrations in a wider frequency range than before. This makes it possible to exhibit good vibration damping effects.

Moreover, according to the method of the present invention, when the frequency of the input vibration becomes higher than the fourth frequency range, the actuating member moves to the second support regardless of the relative movement of the first support with respect to the second support. , and the increase in fluid pressure in the palm portion of the pressure receiving chamber located between the actuating member and the partition member is effectively suppressed.
Compared to the case where the actuating member is supported in a fixed position with respect to the first support body, there is an advantage that an increase in the dynamic spring constant and eventually the vibration transmissibility is significantly suppressed, and therefore the third frequency It also has the advantage that the vibration damping characteristics in a frequency range higher than the above-mentioned frequency range can be significantly improved compared to the conventional method.

In addition, in Japanese Utility Model Application Publication No. 6O-6153J, a mass member having a predetermined mass is elastically supported by a rubber elastic member with respect to a first support body, so as to exert a damper action. A fluid-filled mount device (engine mount) having a structure substantially similar to that of the fluid-filled mount device used in carrying out the method of the present invention has been disclosed; In some cases, the natural frequency of the mass member is 200 t (z or less (generally 100 Hz or less)) in order to improve the vibration isolation effect against input vibration in the low to medium frequency range.
Since the frequency is set to the frequency of ), there is an inherent problem that the vibration transmissibility becomes significantly large in a frequency range higher than that of
I just couldn't do it.

(Example) Hereinafter, in order to clarify the present invention more specifically,
Some embodiments thereof will be described in detail based on the drawings.

First, FIG. 1 shows an example of an engine mount which is a fluid-filled mount device suitable for use in implementing the present invention. In the figure, 10°12 are respectively
First and second supporting metal fittings serving as first and second supporting bodies are arranged to face each other with a predetermined distance apart in the vibration input direction (vertical direction in the figure).

The first support fitting 10 has a truncated cone shape with a relatively small diameter, and is arranged so that the top side of the truncated cone faces the second support fitting 12. On the other hand, the second support fitting 1
2 consists of a container-shaped bottom metal fitting 16 with an outward flange 14 at its opening, and a substantially cylindrical caulking metal fitting 20 with a caulking part 18 at one end in the axial direction. The metal fitting 20 has a bag-like structure in which the metal fitting 20 is caulked and fixed to the flange portion 14 of the bottom metal fitting I6 at a caulking portion 18. As shown in the figure, the second support metal fitting 12 is arranged concentrically with the first support metal fitting IO, with its internal space opening toward the first support metal fitting 10 side.

Here, the rubber elastic body 2 has a substantially tapered cylindrical shape.
2 is integrally vulcanized and bonded to the side surface of the first support fitting 10 at the end on the small diameter side, and integrally attached to the inner surface of the opening of the second support fitting 12 at the end on the large diameter side. The first support metal fitting IO and the second support metal fitting 12 are vulcanized and bonded, and the first support metal fitting IO and the second support metal fitting 12 are elastically connected by this rubber elastic body 22.

Incidentally, mounting poles 1-24 and 26 are erected on the bottom metal fittings 16 of the first support metal fitting 10 and the second support metal fitting 12, respectively, in a state of protruding outward (upward and downward). The engine mount in this embodiment is attached to the engine side using the mounting bolts 24 of the first support fitting 10, and is attached to the vehicle body side using the mounting bolts 26 of the second support fitting 12. A power unit (hereinafter simply referred to as a power unit) including an engine is supported against vibration against the vehicle body.

Moreover, as shown in the figure, here, the rubber elastic body 2
A tapered metal fitting 28 is integrally embedded within the rubber elastic body 22, and the rigidity of the engine mount in the direction perpendicular to the axis is increased by this tapered metal fitting 28.

Here, as shown in the figure, the second support fitting 12 has a peripheral portion held fluid-tight between the bottom metal fitting 16 and the caulking metal fitting 20, and serves as a partition member made of a rubber elastic membrane. A diaphragm 30 is disposed, and a sealed space serving as a fluid storage space is formed between the diaphragm 30 and the first support fitting IO.

A predetermined incompressible fluid such as water, polyalkylene glycol, silicone oil, etc. is sealed within this sealed space.

Further, a partition member 32 is disposed on the second support fitting 12, the peripheral edge of which is held fluid-tight between the bottom metal fitting 16 and the caulking metal fitting 20.
The fluid accommodation space is the pressure receiving chamber 34 on the first support fitting 10 side.
and an equilibrium chamber 36 on the diaphragm 30 side. A circumferential throttle passage 38 is formed on the outer periphery of the partition member 32 to allow the pressure receiving chamber 34 and the equilibrium chamber 36 to communicate with each other.
and the throttle passage 3 through which the incompressible fluid in the equilibrium chamber 36 flows.
8 so that they can flow into each other. Also,
A disk-shaped space with a predetermined area and thickness is formed in the center of the partition member 32, and a movable plate 40 as a movable member made of a rubber material or the like is accommodated in this space.
is installed. When a fluid pressure difference occurs between the pressure receiving chamber 34 and the equilibrium chamber 36, the cylinder 40 moves by a predetermined amount in the direction facing the pressure receiving chamber 34 and the equilibrium chamber 36.
displacement).

Here, the set frequency range for the throttle passage 38 is set to a first frequency range of low frequency, and based on the fact that the incompressible fluid flows through the throttle passage 38, the frequency range of the throttle passage 38 is set to a first frequency range of low frequency, and based on the fact that the incompressible fluid flows through the throttle passage 38, Large-amplitude vibrations can be well damped, and the set frequency range for the movable plate 40 is set to a second frequency range in the medium frequency range, so that the movable plate 40 is connected to the pressure receiving chamber 34 and the equilibrium chamber 36. Based on the movement in the direction opposite to the
Vibration in a frequency range of about Hz or less can be effectively damped or blocked.

Note that the partition member 32 here has a structure in which first and second partition fittings 42 and 44 are overlapped, and the throttle passage 38 is formed by the overlap of these partition fittings 42 and 44. and the movable plate 40
A space is created to accommodate the. In addition, a through hole 46 is formed in each of the partition fittings 42 and 44 to communicate the accommodation space of the movable plate 40 with the pressure receiving chamber 34 and the equilibrium chamber 36, so that the fluid pressure in the pressure receiving chamber 34 and the equilibrium chamber 36 is controlled. It is made to act on the movable plate 40 through these through holes 46.

On the other hand, a pressure receiving chamber 34 is provided on the lower surface of the first support fitting 10.
A coil nose 48 of a predetermined length, which is wound into a tapered cylindrical shape with a large diameter, is concentrically fixed on the tip side while protruding inward. Moreover, at the tip of the coil spring 48,
The pressure receiving chamber 34 is approximately divided into two parts: a chamber portion for 10 examples of the first support fittings and a chamber portion for 32 examples of partition members, and the pressure receiving chamber 34
A disk-shaped mass member 50 made of a rubber material and having a predetermined mass and thickness is fixed concentrically with the coil spring 48, with an annular gap 52 having a predetermined cross-sectional area formed between the coil spring 48 and the inner wall of the coil spring 48.

Here, the set frequency range for the gap 52 is set to a third frequency range of about 200 to 400 Hz, based on the liquid column resonance effect of the incompressible fluid flowing through the gap 52. , a good vibration damping effect can be exhibited against engine transmitted sound in the third frequency range.

Further, here, the natural frequency of the mass member 50 determined by the spring constant of the coil spring 48, the mass of the fluid in the mass member 50 and the gap 52, etc.
The fourth frequency range is set to a higher frequency than the frequency (liquid column resonance frequency) set for input vibration, e.g. 4
Engine transmitted sound of around 50 Hz is effectively attenuated or blocked.

As is clear from the following explanation, in this embodiment, the mass member 50 constitutes an actuating member, and the coil spring 48 constitutes an elastic member.

In the engine mount having such a structure, if the vibration input between the first support metal fitting 10 and the second support metal fitting 12 is about 200 Hz or less (first and second frequency range), As mentioned above, the incompressible fluid flows through the throttle passage 3.
8 or because the movable plate 40 moves in the opposite direction between the pressure receiving chamber 34 and the equilibrium chamber 36, the input vibration of 200 II z or less can be favorably damped or blocked. In addition, the input vibration is 200 to 400
If it is about Hz (third frequency range), the incompressible fluid flows through the gap 52, that is, based on the liquid column resonance effect that occurs in the gap 52, Vibration frequencies of about 400H2 can be well damped.

On the other hand, in such an engine mount, when the frequency of input vibration becomes higher than the natural frequency of the mass member 50, the mass member 50, which had been moved in substantially the same direction as the first support fitting 10, Since the damper action causes the mass member 50 to move in the opposite direction, the movement of the mass member 50 in the opposite direction reduces the fluid pressure in the chamber between the mass member 50 and the partition member 32. The rise is suppressed very well, and therefore the dynamic spring constant,
As a result, an increase in vibration transmissibility is effectively suppressed. In other words, the damper action caused by resonance of the mass member 50 can satisfactorily attenuate or block the input vibration in the fourth frequency range (here, around 450 Il z) corresponding to its natural frequency.

Furthermore, when the frequency of the input vibration becomes higher, that is, higher than the fourth frequency range, the mass member moves to the second support metal fitting 12 regardless of the relative movement of the first support metal fitting 10 to the second support metal fitting 12. 12, the increase in fluid pressure in the chamber portion of the pressure receiving chamber 34 located between the mass member 50 and the partition member 32 is effectively suppressed. An increase in the dynamic spring constant is effectively suppressed. In other words, even in the frequency range higher than the fourth frequency range, the increase in vibration transmissibility is suppressed well, and it is possible to significantly improve the vibration isolation characteristics in the frequency range higher than the fourth frequency range. It can be done.

Therefore, if an engine mount with this structure is interposed between the power unit and the vehicle body to suppress vibration transmission between them, the first, second, and third In addition to exhibiting a good vibration isolation effect against human vibration in three different frequency ranges, the mass member 50
Based on the damper effect of Therefore, it is possible to exhibit a strong anti-vibration effect.

Furthermore, according to the method of this embodiment, it is possible to suppress an increase in the vibration transmissibility well even in a frequency range higher than the fourth frequency range, and therefore, it is possible to suppress an increase in the vibration transmissibility even in a frequency range higher than the fourth frequency range. It is possible to obtain better vibration damping characteristics than conventional methods over almost the entire region.

In addition, in this embodiment, as described above, based on the fact that the incompressible fluid flows through the throttle passage 38 and the movable plate 40 moves in the direction opposite to the pressure receiving chamber 34 and the equilibrium chamber 36, (200 to 40
The input vibration of about 0 Hz and the input vibration of about 450 H2 are well damped or blocked based on the damper action of the mass member 50, and the vibration is reduced in the frequency range of about 450 Hz or less. 500 is required for engine mounts because the increase in transmission rate is well suppressed.
It has the advantage that good vibration damping characteristics can be obtained in almost the entire range below about Hz.

Further, in this embodiment, as described above, the elastic member supporting the mass member 50 is composed of the tapered coil spring 48 having non-linear spring characteristics, and the mass member 50 is connected to the partition member 3.
2 and is compressed, its spring constant increases rapidly. Therefore, in order to determine the natural frequency of the mass member 50, the spring constant of the coil spring 48 even in an unrestrained state Even if it is set to a certain small value, there is an advantage that an extremely good stopper function can be achieved based on the contact of the mass member 50 with the partition member 32.

Furthermore, in this embodiment, since the mass member 50 itself is made of a rubber material, there is no need to separately provide a buffer rubber layer for mitigating the impact when the mass member 50 and the partition member 32 come into contact. There are also advantages.

Next, other examples of engine mounts suitable for use in the method of the present invention will be explained based on FIGS. 2 to 4, respectively. Note that the engine mounts shown in FIGS. 2 to 4 are different from the engine mounts in the above embodiments.
Since the only difference is the configuration of the actuating member and the elastic member, only the configuration of the actuating member and the elastic member will be described in detail below.

That is, in the engine mount shown in FIG. 2, as shown in the same figure, the disk-shaped mass member 54 having a predetermined mass as an operating member is made of a metal material, The mass member 54 is attached to the first support fitting 10 via a cylindrical coil spring 56 as an elastic member, and a ring-shaped buffer rubber A layer 58 is vulcanized integrally with the mass member 54.

The natural frequency of the mass member 54 is set to the same frequency as in the above embodiment, and based on the damper effect due to the resonance, the input vibration in the fourth frequency range of around 450 Hz is well damped or It is designed to be blocked.

Even if an engine mount with such a structure is used, it is possible to obtain the same vibration-proofing characteristics as in the above embodiment, and it is possible to exhibit a good vibration-proofing effect in almost all the frequency ranges required for the engine mount. It is possible.

In addition, when a coil spring is used as the elastic member as in the above embodiment, in order to prevent the occurrence of hammering noise between the coil springs, a coil spring with excellent wear resistance is used.
It is desirable to coat an elastic tube made of polyether/urethane thermoplastic elastomer having hydrolysis resistance, hard rubber, or the like. It is also possible to use such an elastic tube as a mass damper for a coil spring.

Further, in the engine mount shown in FIG. 3, a rubber member 60 having a predetermined thickness is used as an elastic member that supports a metal mass member 62. The natural frequency of the mass member 62 is set to the same frequency as in the previous embodiment.

The mass member 62 in this embodiment includes a disc-shaped plate portion 64 with a predetermined thickness and a protrusion 66 erected at the center of the upper surface of the plate portion 64, and is integrally attached to the rubber member 60. The protrusion 66 is concentrically screwed onto a screw member 68 fixed to the screw member 68 . Further, the rubber member 60 is screwed and attached to the first support fitting 10 via a screw member 70 that is integrally vulcanized and bonded. Furthermore, in the plate portion 64 of the mass member 62,
An annular buffer rubber layer 72 is integrally provided so as to cover the outer periphery of the lower surface with a predetermined thickness.

Furthermore, in the engine mount shown in FIG. 4, a metal mass member 74 having a structure similar to that of the mass member 62 in the above embodiment is provided with A thermoplastic elastomer 80 is integrally molded so as to cover the section 78 , and the thermoplastic elastomer i30 extends above the protrusion 78 of the mass member 74 and has a predetermined cross-sectional area. By being fixed to the support fitting 10, the mass member 74 is elastically attached to the first support fitting 10. The natural frequency of this mass member 74 is set to the same frequency as in the previous embodiment.

Even if engine mounts having the structures shown in FIGS. 3 and 4 are used, the same effects as in the above embodiment can be obtained.

Note that when thermoplastic elastomer is used as the elastic member, as in the engine mount shown in Fig. 4 above,
Those with excellent abrasion resistance and hydrolysis resistance,
For example, it is desirable to use Santopre, Hytrel, etc. (both are trade names).

Although several embodiments of the present invention have been described in detail above, these are merely illustrative, and the present invention is not limited to these specific examples, and various modifications may be made without departing from the spirit thereof. .

It goes without saying that the present invention can be implemented with modifications, improvements, etc.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of an engine mount which is one of the fluid mount devices suitable for use in carrying out the present invention, and FIGS. 2, 3 and 4 are respectively FIG. 3 is a longitudinal sectional view showing another example of an engine mount suitable for use in carrying out the invention. 10: First support metal fitting (first support body) 12: Second support metal fitting (second support body) 22: Go 1, hanging body 30: Diaphragm (partition member) 32: Partition member 34 : Pressure receiving chamber 36: Equilibrium chamber 38: Restriction passage 40: Movable plate (
movable parts)

Claims (1)

[Claims] First and second supports arranged to face each other in the vibration input direction; interposed between the first and second supports to elastically connect them. a rubber elastic body; a partition member, at least a part of which is constituted by an elastic membrane, and which is disposed on the second support and forms a fluid accommodation space between it and the first support; a predetermined incompressible fluid sealed in the accommodation space; a partition member that partitions the fluid accommodation space into a pressure receiving chamber on the first support side and an equilibrium chamber on the partition member side; the pressure receiving chamber and the equilibrium a throttle passage that allows the pressure receiving chamber and the equilibrium chamber to communicate with each other; a movable member disposed so as to be deformed or displaced by a predetermined amount in opposing directions in response to a fluid pressure difference within the pressure receiving chamber and the equilibrium chamber; A fluid-filled type comprising an actuating member protruding from the first support into the pressure receiving chamber in a state where the chamber is approximately divided into two parts: a chamber on the first support side and a chamber on the partition member side. When a mounting device is used to attach the first and second supports to two members to which vibrations are transmitted, respectively, and to suppress vibration transmission between the two members, the operating member of the fluid-filled mounting device; is elastically supported by the first support via a predetermined elastic member, and the actuating member is a mass member having a predetermined mass, so that the actuating member exhibits a damping action. By this, the input vibration in the first frequency range is generated based on the incompressible fluid flowing through the restriction passage, and the input vibration is generated in the first frequency range based on the deformation or displacement of the movable member. while attenuating or blocking input vibrations in a second frequency range higher than the above, the incompressible fluid flows through a gap formed between the actuating member and the inner wall of the pressure receiving chamber. Based on this, the input vibration is in a third frequency range higher than the second frequency range, and based on the damping action of the actuating member, the input vibration is in a fourth frequency range higher than the third frequency range. 1. A vibration isolation method using a fluid-filled mounting device, characterized in that input vibrations are attenuated or blocked.