JPH08291843A - Fluid mount - Google Patents

Abstract

PURPOSE: To keep a dynamic constant lower and provide sufficient damping. CONSTITUTION: A fluid mount is provided with an elastic body 7 elastically connecting two fixing sections 3 and 5, two fluid chambers 11 and 13 which are provided between the two fixing sections 3 and 5 and filled with fluid, a communication hole 17, which communicates the fluid chambers 11 and 13 and a mass body 21, which forms orifices 19 in the gap between, and the internal faces 17a, which are vibrationably and elastically supported to the communication hole 17. For this reason, when the mass body 21 resonates along the axial direction of the communication hole 17, in the area of smaller frequency than the resonant frequency of the mass body 21, effective orifice length is lengthened, and in the area exceeding the resonant frequency of the mass body 21, effective orifice length is shortened.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to fluid mounts.

[0002]

19 to 21 are sectional views showing a conventional fluid mount of this type. These fluid mounts increase the loss factor by increasing the loss factor for low-frequency vibration with large amplitude, and increase the damping force of the dynamic spring constant due to the stick of the orifice for vibrations at frequencies above the maximum loss factor. The purpose is to mitigate the rise.

FIG. 19 shows a fluid mount 101 disclosed in Japanese Patent Laid-Open No. 60-159435, which includes a first substrate 103 attached to a power unit, a second substrate 105 attached to a vehicle body, and a fluid inside. A mount rubber 109 having a chamber 107, a partition plate 113 having an outer peripheral edge fixed to the first substrate 103, and a diaphragm 115 are provided, and the fluid chamber 107 is divided into a first fluid chamber 117 and a second fluid chamber by the partition plate 113. It is divided into chambers 119.

A valve mechanism 121 and an orifice 123 are provided in parallel on the partition plate 113. The valve mechanism 121 includes an annular portion 125 having a U-shaped cross section and an annular portion 125.
A movable plate 127 movably provided therein, and the first fluid chamber 117 and the second fluid chamber 11 are provided in the annular portion 125.
A communication hole 129 that communicates with 9 is formed. The movable plate 127 is movable by high frequency vibration (for example, 100 to 170 Hz) and is restrained by low frequency large amplitude vibration (for example, 5 to 13 Hz).

When a large amplitude vibration in a low frequency range (for example, 5 to 13 Hz) that causes an engine shake is input,
The mount rubber 109 expands and contracts greatly, and the first fluid chamber 1
17, the movable plate 127 is locked to the annular portion 125, the movable plate 127 closes the communication hole 129,
The fluid in the orifice 123 resonates to generate a large damping force.

On the other hand, for a small-amplitude vibration input in the high frequency range (for example, 100 to 170 Hz) that produces a muffled sound,
Since the pressure change in the first fluid chamber 117 is large, the fluid cannot flow through the orifice 123, and the fluid is
Of the fluid chamber 117. In this case, the mount rubber 109 expands and contracts, and the valve mechanism 121
The movable plate 127 of is moved. That is, in the fluid mount 101, the movable plate 127 moves in accordance with the vibration of the fluid, so-called rattling mechanism, so that the high frequency range (100 to 17).
It absorbs small amplitude vibration at 0Hz) and suppresses the increase of the dynamic spring constant in such high frequency range.

FIG. 20 shows a fluid mount 131 described in Japanese Unexamined Patent Publication No. 57-84220.
The basic structure is almost the same as that of the fluid mount 101 shown in FIG. 19 except that 43 is provided on the movable plate 127 itself. That is, in the low frequency range, a large damping force is generated by the fluid resonance in the orifice 143, and in the high frequency range, the backlash mechanism of the movable plate 127 absorbs the vibration to suppress the increase of the dynamic spring constant.

FIG. 21 shows a fluid mount 141 disclosed in Japanese Patent Laid-Open No. 59-231239.

The fluid mount 141 has a partition plate 143 for partitioning the first fluid chamber 117 and the second fluid chamber 119.
Is supported by the first substrate 103 via an annular elastic member 145, and an orifice 147 is formed in the partition plate 143. The vibration of the partition plate 143 is in phase with the vibration of the fluid in the low frequency range below the resonance frequency of the partition plate 143,
Inversion occurs at the resonance frequency of the partition plate 143, and in a high frequency range higher than the resonance frequency of the partition plate 143, the phase is opposite to the vibration of the fluid. The effective area of the partition plate 143 is formed larger than the effective area of the elastic member 145.

In the low frequency range (for example, 5 to 13 Hz) in which engine shake occurs, the partition plate 143 and the fluid vibrate in the same phase, and the fluid in the orifice 147 resonates to generate a large damping force.

On the other hand, in a high frequency range (for example, 100 to 170 Hz) that produces a muffled sound, the partition plate 143 and the fluid vibrate in opposite phases, and the effective area of the partition plate 143 is the elastic member 1.
Since it is formed larger than the effective area of 45, the second
And the force acting on the first substrate 103 from the first substrate 103 and the force acting on the first substrate 103 due to the fluid pressure of the fluid generated by the small amplitude vibration of the partition plate 143 cancel each other out. Fit. That is, this fluid mount 1
In 41, due to the vibration action of the one-degree-of-freedom system composed of the partition plate 143 and the elastic member 145, the high frequency range (100 to 1
It absorbs small amplitude vibrations at 70Hz) and suppresses the increase of the dynamic spring constant in such high frequency range.

[0012]

However, in the fluid mounts 101 and 131 shown in FIGS. 19 and 20, the movable plate 127 is attached to the annular portion 1 in the low frequency range where damping force is required.
Since the structure is to be locked to 25, the movable plate 12 locked
There was a possibility that 7 moved due to the difference in fluid pressure of the fluid, and the communication hole 129 was not completely closed. Therefore, the amount of fluid passing through the orifices 123 and 143 is substantially reduced, and the damping force may not be efficiently obtained.

On the other hand, in the fluid mount 141 shown in FIG. 21, the fluid mounts 101 and 13 shown in FIGS.
Since there is no rattling mechanism as in No. 1, a high loss factor can be efficiently obtained in the low frequency range, but on the other hand, since the partition plate 143 vibrates in the same phase as the fluid, the inertial force of the partition plate 143 is increased. It is transmitted to the first substrate 103. This inertial force cannot be suppressed to a small level because a predetermined hydraulic pressure must be applied to the fluid in the high frequency range, and the fluid mount 10 shown in FIGS.
Compared with 1,131, an increase in the dynamic spring constant in the low frequency range cannot be denied.

The present invention has been made to solve such conventional problems, and provides a fluid mount capable of suppressing the dynamic spring constant to a low level and obtaining sufficient damping regardless of the frequency range of the fluid. It is an object.

[0015]

In order to achieve the above object, the invention according to claim 1 is provided between an elastic body that elastically connects two fixing portions and the two fixing portions. An orifice is formed between two fluid chambers filled with fluid, a communication hole that communicates between the two fluid chambers, and an inner surface of the communication hole that is elastically supported in a vibrating manner with respect to the communication hole. And a mass body that operates.

The invention according to claim 2 is the fluid mount according to claim 1, wherein the orifice is formed along the hole direction of the communication hole and the inner surface of the communication hole and the mass body. It is a gap with the outer surface, and the mass body vibrates in the hole direction of the communication hole.

According to a third aspect of the present invention, there is provided the fluid mount according to the second aspect, wherein the upper and lower end portions of the mass body in the vibration direction are the upper and lower end portions of the communication hole when the mass body is not vibrating. It is characterized by almost matching with.

A fourth aspect of the present invention is the fluid mount according to the first aspect, wherein the orifice is formed on an outer surface of the mass body and defines the first fluid chamber and the second fluid chamber. The spiral inner groove portion that communicates with the first fluid chamber and the second fluid chamber that are formed on the inner surface of the communication hole do not directly communicate with each other, but at a position facing the inner groove portion through the inner groove portion. A spiral outer groove portion that communicates with the first fluid chamber and the second fluid chamber and has a pitch shorter than the maximum amplitude of the mass body, the mass body along the hole direction of the communication hole. It is characterized by vibrating.

According to a fifth aspect of the present invention, in the fluid mount according to the fourth aspect, the inner groove portion and the outer groove portion substantially face each other when the mass body is not vibrating. It is a feature.

The invention according to claim 6 is the fluid mount according to any one of claims 1 to 5, wherein the resonance frequency of the mass body is set higher than the maximum loss factor frequency. It is a feature.

The invention according to claim 7 is the fluid mount according to any one of claims 1 to 5, wherein the communication hole is elastically supported so as to be vibrable with respect to one of the fixing portions. And a supporting elastic constant between the one fixing portion and the vibrating member is set to be smaller than a supporting elastic constant between the vibrating member and the mass body. Is.

The invention according to claim 8 is the fluid mount according to claim 7, wherein the resonance frequency of the mass body is
The maximum loss factor frequency is set to be included in a frequency range in which the mass body and the oscillating member are displaced in phase and the oscillating member and the fluid are displaced in opposite phase. is there.

The invention according to claim 9 is the fluid mount according to any one of claims 1 to 8, characterized in that the mass body is elastically supported by a leaf spring. .

The invention according to claim 10 is the fluid mount according to any one of claims 1 to 8, characterized in that the mass body is elastically supported by a coil spring.

The eleventh aspect of the present invention is the fluid mount according to any one of the first to eighth aspects, wherein the mass body is elastically supported by a rubber member. .

The invention according to claim 12 is the fluid mount according to any one of claims 1 to 11, wherein one of the two fixing parts is connected to the power unit side and the other is to the vehicle body side. It is characterized by being connected.

The invention according to claim 13 is the fluid mount according to any one of claims 1 to 11, characterized in that the two fixing portions are respectively connected to a vehicle body member. Is.

[0028]

According to the first aspect of the present invention, when the composite vibration including the resonance frequency of the mass body is input to the fluid mount from the fixed portion, the mass body resonates and is largely displaced. The shape of the orifice formed between the inner surface and the inner surface changes with time.

In the frequency range lower than the resonance frequency of the mass body (first frequency range), when a mass body vibrating at a high frequency is seen from a fluid vibrating at a low frequency, the mass body appears to vibrate at high speed. Therefore, the mass body is in a state in which it exists as if it exists over almost the entire displaceable range.

On the other hand, in the frequency range beyond the resonance frequency of the mass body (second frequency range), when the movement of the mass body is seen from the fluid, the mass body seems to vibrate slowly.

Therefore, regarding the state of the orifice for the fluid, the first frequency range is blocked more than the second frequency range, and the fluid becomes difficult to flow. That is, at least one of the effective orifice length and the effective orifice diameter is different between the first frequency range and the second frequency range, and the effective orifice length of the second frequency range is shorter than that of the first frequency range. , Or the effective orifice diameter becomes large.

It has been found that the frequency of liquid resonance in the orifice rises in inverse proportion to the effective orifice length and in proportion to the effective orifice diameter. Therefore, in the second frequency range that exceeds the first frequency range, the frequency at which the orifice causes sticking can be substantially increased, and the dynamic spring constant due to the sticking of the orifice can be reduced.

Further, since the mass body is not for applying hydraulic pressure to the fluid but for forming an orifice between the mass body and the communication hole, the weight of the mass body can be kept small and resonating. The inertial force transmitted from can be suppressed to a small value. Therefore, the dynamic spring constant does not increase due to the inertial force of the mass body, and the dynamic spring constant can be reduced even in the frequency range below the resonance frequency of the mass body including the first frequency range. .

Further, since the rattling mechanism is not provided, there is no fear that the damping force is lowered due to the rattling mechanism at the frequency where the damping is desired to be increased, and the high damping force can be efficiently secured at the desired frequency. .

In the invention described in claim 2, in addition to the function of the invention described in claim 1, the orifice is a gap formed along the hole direction of the communication hole, and the mass body is in the hole direction of the communication hole. Since it vibrates along with, it is possible to accurately reduce only the effective orifice length with a simple structure.

That is, when the composite vibration including the resonance frequency of the mass body is input, the mass body resonates and the orifice moves up and down in the vibration direction according to the displacement of the mass body.

In the first frequency range lower than the resonance frequency of the mass body, when a mass body vibrating at a high frequency is seen from a fluid vibrating at a low frequency, the mass body appears to vibrate at high speed.
It is as if a mass body having a length corresponding to the maximum amplitude exists along the hole direction of the communication hole.

On the other hand, in the second frequency range beyond the resonance frequency of the mass body, when the movement of the mass body is seen from the fluid, the mass body seems to be slowly vibrating, so
It is as if a mass body shorter than the frequency range of exists.

Therefore, when comparing the state of the orifice between the first frequency range and the second frequency range, the effective orifice diameter is constant because it is determined by the distance between the inner surface of the communication hole and the outer surface of the mass body. Since the orifice length in the second frequency range is shorter than that in the first frequency range, only the effective orifice length can be accurately reduced in the second frequency range.

According to the third aspect of the invention, in addition to the function of the second aspect of the invention, the upper and lower ends of the mass body in the vibration direction are substantially aligned with the upper and lower ends of the communication hole when the mass body is not vibrating. Because of the resonance of the mass body, the orifice moves up and down in the vibration direction, the orifice length becomes the minimum at the maximum amplitude of the mass body, and the orifice when the upper and lower ends of the mass coincide with the upper and lower ends of the communication hole. Maximum length. As a result, the maximum value of the effective orifice length is restricted to the length between the upper and lower end portions of the communication hole, and the effective orifice length is set to a substantially constant length in the first frequency range lower than the resonance frequency of the mass body. The second frequency that exceeds the resonance frequency of the mass
In the frequency range of, the effective orifice length can be reduced more accurately.

That is, in the first frequency range lower than the resonance frequency of the mass body, the effective orifice length becomes almost equal to the distance between the upper and lower end portions of the communication hole, and the effective orifice length exceeds the resonance frequency of the mass body in the second frequency range. In the frequency range of 1, the orifice length increases and decreases with the distance between the upper and lower ends of the communicating hole being the maximum, but the time-averaged effective orifice length is shorter than the distance between the upper and lower ends of the communicating hole.

Therefore, the effective orifice length is approximately equal to the distance between the upper and lower ends of the communication hole in the first frequency range,
In the second frequency range, the distance between the upper and lower end portions of the communication hole is surely shorter than that in the second frequency range. Therefore, a substantially constant orifice length is obtained in the first frequency range, and only the effective orifice length is properly determined in the second frequency range. Can be reduced to

According to the invention described in claim 4, in addition to the function of the invention described in claim 1, the orifice includes an inner groove portion formed on the outer surface of the mass body and an outer groove portion formed on the inner surface of the communication hole. Since the mass body vibrates along the hole direction of the communication hole, only the effective orifice diameter can be increased accurately with a simple structure.

That is, when a composite vibration including the resonance frequency of the mass body is input, the mass body resonates and vibrates.
The inner groove portion moves up and down in the vibration direction according to the displacement of the mass body. At this time, since the outer groove portion has a pitch shorter than the maximum amplitude of the mass body, the inner groove portion always moves to a position opposite to the position facing the outer groove portion during one vibration of the mass body. The diameter of the orifice formed by the inner groove portion and the outer groove portion is the maximum diameter of the inner groove portion and the outer groove portion at the position where they face each other, and the minimum diameter of only the inner groove portion at the position where they are offset.

In the first frequency range lower than the resonance frequency of the mass body, when a mass body vibrating at a high frequency is seen from a fluid vibrating at a low frequency, the mass body appears to vibrate at high speed.
As if only the inner groove portion exists, the effective orifice diameter becomes the minimum diameter which is almost equal to the depth of the inner groove portion.

On the other hand, in the second frequency range that exceeds the resonance frequency of the mass body, when the movement of the mass body is observed from the fluid, it appears that the mass body is slowly vibrating. Therefore, the orifice diameter becomes maximum when the inner groove portion and the outer groove portion face each other, and becomes minimum when the inner groove portion deviates from the outer groove portion, but the time-averaged effective orifice diameter is smaller than the depth of the inner groove portion. growing.

As a result, only the effective orifice diameter can be increased accurately in the second frequency range, and the frequency at which the orifice causes sticking can be substantially increased, and the dynamic spring constant due to the sticking of the orifice can be reduced. Can be achieved.

According to the invention described in claim 5, in addition to the action of the invention described in claim 4, at the resonance frequency of the mass body, the mass body is displaced by 90 ° with respect to the fluid pressure of the fluid. When the fluid pressure of the fluid becomes maximum, the displacement of the mass body becomes 0, and the orifice diameter becomes maximum. That is, at the resonance frequency of the mass body, the orifice diameter becomes maximum when the fluid pressure of the fluid is maximized, and the fluid easily flows through the orifice, so that the frequency at which the orifice sticks can be further increased. The dynamic spring constant due to the stick can be reduced more effectively.

In the invention described in claim 6, in addition to the operation of the invention described in any one of claims 1 to 5, since the resonance frequency of the mass body is higher than the maximum loss factor frequency, the amplitude is large. The maximum loss factor frequency can be set in the frequency range to increase the damping force, and the dynamic spring constant can be reduced in the frequency range higher than the maximum loss factor frequency. Therefore, it is possible to simultaneously realize a high loss factor at a frequency where attenuation is desired to be increased and a low dynamic spring in the entire frequency range.

In the seventh aspect of the invention, the vibrating member and the mass body vibrate in a two-degree-of-freedom system, and the vibrating member and the mass body resonate at two resonance frequencies on the low frequency side and the high frequency side. At the same time, the two are displaced in the same phase up to the inversion frequency between the two resonance frequencies and are inverted at the inversion frequency. Further, the displacement between the fluid and the vibrating member is in-phase up to the resonance frequency on the low frequency side, opposite phase from the resonance frequency on the low frequency side to the inversion frequency,
The phase from the inversion frequency to the resonance frequency on the high frequency side is in phase, and the phase above the resonance frequency on the high frequency side is in phase.

In the frequency range lower than the inversion frequency range (first frequency range), since the vibrating member and the mass body are displaced in phase, neither the orifice length nor the orifice diameter fluctuates,
It becomes almost constant.

On the other hand, the frequency range exceeding the inversion frequency (second
In the frequency range of), the vibrating member and the mass body are displaced in opposite phases, so the shape of the orifice changes greatly according to the displacement of the mass body, and when the movement of the mass body is observed from the fluid, the mass body slowly moves. It seems to vibrate. Therefore, the effective orifice length is shorter or the effective orifice diameter is larger in the second frequency range than in the first frequency range.

As a result, like the invention according to claim 1, in the second frequency range exceeding the first frequency range,
The frequency at which the orifice causes sticking can be increased, and the dynamic spring constant due to the sticking of the orifice can be reduced. Further, by adopting the configuration described in claims 2 to 5, it is possible to obtain the same operation as that of the invention described in claims 2 to 5.

Further, in the second frequency range, the vibrating member and the mass body are displaced in opposite phases, and the shape of the orifice is greatly changed according to the displacement of the mass body. In comparison with the invention described in any one of 1, the effective orifice length can be reduced or the effective orifice diameter can be increased more effectively, and the dynamic spring constant due to the stick of the orifice can be reduced more effectively. it can.

Further, in the frequency range lower than the resonance frequency on the low frequency side, the displacement of the fluid and the vibrating member are in phase, and the fluctuation of the fluid pressure of the fluid is absorbed by the vibrating member. As a result, the fluid flowing through the orifice is reduced. Therefore, the dynamic spring constant can be further reduced in this frequency range.

Furthermore, in the second frequency range from the inversion frequency to the resonance frequency on the high frequency side, the displacement of the vibrating member and the mass body are in phase, and the fluid pressure of the fluid is absorbed by the vibrating member. The rise is suppressed, and the dynamic spring constant can be further reduced in this frequency range.

According to the invention described in claim 8, in addition to the action of the invention described in claim 7, the maximum loss factor frequency is such that the mass body and the vibrating member are displaced in the same phase, and Is in the frequency range in which the phase shifts in the opposite phase, the loss factor becomes maximum when the orifice length and the orifice diameter do not change and the vibrating member is displaced in the phase opposite to the fluid pressure of the fluid. Therefore, it is possible to more effectively increase the loss factor by utilizing the reaction force against the hydraulic pressure, and it is more effective to increase the loss factor at the frequency where attenuation is desired to be increased and to reduce the dynamic spring in the entire frequency range. Can be realized in real time.

In the invention described in claim 9, in addition to the operation of the invention described in any one of claims 1 to 8, since the mass body is elastically supported by the leaf spring, a fluid mount having a simple structure can be obtained. can do.

In the invention described in claim 10, claims 1 to
In addition to the function of the invention described in any one of claims 8 to 11, the mass body is elastically supported by the coil spring, so that the displaceable range of the mass body can be increased, and the effective orifice length is shortened or the effective orifice is reduced. The diameter can be increased. Therefore, the dynamic spring constant can be further reduced.

According to the invention described in claim 11, claims 1 to
In addition to the effect of the invention described in any one of claims 8, the mass body is elastically supported by the rubber member, so that the generation of vibration noise of the mass body can be suppressed.

In the invention described in claim 12,
In addition to the effect of the invention according to any one of claims 11 to 2,
One of the two fixed parts was connected to the power unit side and the other was connected to the vehicle body side, and this fluid mount was used as an engine mount.Therefore, when the vehicle was running, low-frequency large-amplitude vibration input from the engine and road surface The high-frequency small-amplitude vibration input from can be reliably absorbed, and a good anti-vibration effect can be obtained.

In the invention described in claim 13,
In addition to the effect of the invention according to any one of claims 11 to 2,
Each of the two fixed parts was connected to the body member and this fluid mount was used as a member insulator.
When the vehicle is traveling, it is possible to reliably absorb the vibration input from the road surface and obtain a good vibration damping effect.

[0063]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the invention described in claim 1, claim 2, claim 3, claim 6, claim 9 or claim 12 will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing this embodiment, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is an enlarged perspective view of a B portion of FIG. 1, and FIG.
Is an enlarged schematic diagram showing an effective orifice length for low frequency vibration, FIG. 5 is an enlarged schematic diagram for explaining a state of a mass member for high frequency vibration, FIG. 6 is an enlarged schematic diagram showing an effective orifice length for high frequency vibration, and FIG. 7 is an input. It is a characteristic view of the fluid mount of FIG. 1 with respect to the frequency of vibration, (a) is a relationship diagram of the frequency of an input vibration, a dynamic spring constant, and a loss factor, (b) is a relationship of the frequency of an input vibration, and an effective orifice length. FIG. 6C is a relationship diagram between the frequency of the input vibration and the displacement of the mass member.

As shown in FIGS. 1 and 2, this fluid mount 1 is used as an engine mount, and is connected to the vehicle body side with a plate-shaped first fixing portion 3 connected to the power unit side. Plate-shaped second fixing portion 5
A cylindrical elastic body 7 that elastically connects the two fixing parts 3 and 5, a fluid chamber 9 provided between the two fixing parts 3 and 5 and filled with a fluid, and a second A partition part 15 fixed to the fixing part 5 to partition the fluid chamber 9 into a first fluid chamber 11 and a second fluid chamber 13, and a first fluid chamber 11 and a second fluid chamber formed in the partition part 15. A communication hole 17 that communicates with 13;
The communication hole 1 is elastically supported by the communication hole 17 so as to be freely vibrated.
7, and a mass member 21 as a mass body that forms an orifice 19 between the inner surface 17a and the inner surface 17a.

A hole 23 is formed in the second fixing portion 5,
A diaphragm 25 that covers the hole 23 and a cover 27 that covers the outside of the diaphragm 25 are provided outside the second fixing portion 5. The tip 27a of the cover 27 is joined to the outer surface of the second fixing portion 5 with the outer peripheral edge 25a of the diaphragm 25 sandwiched therebetween.

Both end surfaces 7a and 7b of the elastic body 7 are fixed to the two fixing portions 3 and 5 by vulcanization adhesion, and the fluid chamber 9 is surrounded by the elastic body 7 and both fixing portions 3 and 5. There is. The partition portion 15 includes a disk-shaped flat plate portion 29 and a flat plate portion 2
9 has a side plate portion 31 that is bent from the peripheral edge of the side plate 9 and has a tip 31a that is widened.
1a is joined to the second fixing portion 5.

As shown in FIG. 3, the flat plate portion 2 of the partition portion 15
9 is provided with a cylindrical communication hole forming portion 33 having an inner peripheral surface serving as the inner surface 17a of the communication hole 17, and the first fluid chamber 11 and the second fluid chamber 13 communicate with each other only through the communication hole 17. are doing.

The mass member 21 is formed in a cylindrical shape, and is elastically supported inside the communication hole 17 by a leaf spring 35.
In the non-vibrating state, the upper and lower end surfaces 21a and 21b as the upper and lower end portions of the mass member 21 substantially match the upper and lower end surfaces 33a and 33b of the communication hole forming portion 33 as the upper and lower end portions of the communication hole 17, respectively.

The leaf spring 35 is substantially 1 in the circumferential direction of the mass member 21.
A total of four sheets are provided at two locations shifted by 80 °, two sheets at the top and two sheets at the bottom. Both ends of each leaf spring 35 are connected to the groove portion 39 formed on the outer peripheral surface 37 of the mass member 21 and the communication hole forming portion 33.
The mass member 21 vibrates along the hole direction of the communication hole 17 by engaging with the groove portions 41 formed on the inner peripheral surface (the inner surface 17a of the communication hole 17).

The orifice 19 is the inner surface 17 of the communication hole 17.
It is a cylindrical gap formed between a and the outer peripheral surface 37 of the mass member 21, and connects the first fluid chamber 11 and the second fluid chamber 13 along the hole direction of the communication hole 17. There is. In addition,
The leaf spring 35 is formed in a size and shape that does not block the flow of the fluid by closing the orifice 19.

Next, the operation of this embodiment will be described.

The mass member 21 and the leaf spring 35 form a one-degree-of-freedom vibration system, and the mass member 2 has a resonance frequency ω _m .
1 is greatly displaced. The resonance frequency ω of this mass member 21
_As shown in FIGS. 7A and 7C, _m is set to be higher than the resonance frequency (maximum loss factor frequency ω _L ) of the fluid in the orifice 19 where the loss factor LF becomes maximum. The maximum loss factor frequency ω _L is set to a low frequency range (for example, 5 to 13 Hz) that causes engine shake, the resonance frequency ω _m of the mass member 21 is higher than the maximum loss factor frequency ω _L , and the muffled sound is generated. Is set to the low frequency side of the middle and high frequency range (for example, 100 to 170 Hz). The maximum loss factor frequency ω _L is set by adjusting the orifice diameter, which is the distance between the outer diameter of the mass member 21 and the inner diameter of the communication hole 17.

Vibration from the engine is input from the first fixed portion 3, and vibration from the road surface is input from the second fixed portion 5. When the vehicle is running, the vibration from the road surface causes the mass member 2
Since it is a composite vibration including the resonance frequency of 1, the mass member 2
1 always resonates and is largely displaced. When the mass member 21 is displaced, the shape of the orifice 19 changes accordingly with time.

Here, the orifice 19 is a gap between the inner surface 17a of the communication hole 17 and the outer peripheral surface 37 of the mass member 21 formed along the hole direction of the communication hole 17, and the mass member 21.
Oscillates along the hole direction of the communication hole 17, so that only the orifice length of the shape of the orifice 19 changes with time. That is, when the composite vibration including the resonance frequency of the mass member 21 is input, the mass member 21 resonates and the orifice 19 moves up and down in the vibration direction according to the displacement of the mass member 21. The upper and lower end surfaces 21a and 21b of the mass member 21 are the upper and lower end surfaces 33 of the communication hole forming portion 33 when the mass member 21 is not vibrating.
Since they substantially coincide with a and 33b, the mass member 21 alternately projects to the first fluid chamber 11 side and the second fluid chamber 13 side with vibration. Therefore, the orifice length becomes maximum (distance between the upper and lower end surfaces 33a and 33b of the communication hole forming portion 33) in a state where the mass member 21 is not displaced, and the mass member 2
1 is the smallest when it is displaced most.

In the low frequency range (for example, 5 to 13 Hz) as the first frequency range in which the engine shake occurs, large amplitude vibration is input, but the maximum loss factor frequency ω _L is set in this frequency range. , A large damping force is generated. Since the fluid mount 1 is not provided with a backlash mechanism, there is no risk of a reduction in the damping force due to the backlash mechanism, and a high damping force can be efficiently secured.

Further, since the mass member 21 is provided not to apply the hydraulic pressure to the fluid but to form the orifice 19, the weight of the mass member 21 is suppressed to be small, and the mass member 21 from the resonating mass member 21 is suppressed. The inertial force transmitted to the second fixed portion 5 can be suppressed to be small. Therefore, the dynamic spring constant does not increase due to the inertial force of the mass member 21, and a low dynamic spring constant can be obtained for low frequency vibration.

Next, the state of the orifice 19 with respect to the fluid will be described.

[0079] In the range of frequencies lower than the resonant frequency omega _m of the mass member 21, looking at the movement of the mass member 21 which vibrates the fluid to vibrate at a low frequency at a high frequency (resonance frequency omega _m), the mass member 21 is a high speed It seems to vibrate. For this reason,
As shown in FIG. 4, the mass member 21 exists as if it exists over almost the entire displaceable range,
That is, the mass member 21 having a length corresponding to the maximum amplitude exists along the hole direction of the communication hole 17. Therefore, the effective orifice length La for the low frequency vibration is approximately equal to the distance (communication hole length) L0 between the upper and lower end surfaces 33a and 33b of the communication hole forming portion 33.

On the other hand, in the middle and high frequency range (for example, 100 to 170 Hz) as the second frequency range that produces muffled sound,
Small amplitude vibration is input.

Since the middle-high frequency range exceeds the resonance frequency ω _m of the mass member 21, when the movement of the mass member 21 is observed from the fluid, it appears that the mass member 21 is slowly vibrating. Therefore, as shown in FIG. 5, the orifice length for medium and high frequency vibration is as follows:
1a, 21b and upper and lower end surfaces 33a, 3 of the communication hole forming portion 33
3b (the solid line in FIG. 5) when it matches 3b, the communication hole length L
0 is the maximum, and the upper and lower end surfaces 33a, 33 of the communication hole forming portion 33 at the maximum amplitude of the mass member 21 (broken line in FIG. 5).
b and the distance L between the lower upper end surfaces 21b and 21a of the mass member 21
Although it increases and decreases with m as the minimum, the time-averaged effective orifice length La is certainly shorter than the communicating hole length L0, as shown in FIG.

Therefore, when comparing the state of the orifice 19 in the low frequency region and the medium and high frequency regions, the orifice diameter is constant, but the effective orifice length La is almost equal to the communication hole length L0 in the low frequency region, and the medium and high frequencies. Since it is shorter than the communication hole length L0 in the frequency range, the effective orifice length La for low frequency vibration can be maintained substantially constant, and the effective orifice length La for medium and high frequency vibration can be appropriately reduced.

The difference in the orifice characteristics between the low frequency region and the middle and high frequency regions will be further described with reference to FIG. In addition,
Solid lines Kd, LF, La, and Dm in FIG. 7 indicate the dynamic spring constant, loss factor, effective orifice length, and displacement of the mass member, respectively, and broken lines Kd0 and La0 indicate that the effective orifice length is constant (L0). 5 is a diagram showing a dynamic spring constant and an effective orifice length of a conventional general fluid mount.

In the low frequency range, the effective orifice length La is almost equal to the communication hole length L0, but when it exceeds the resonance frequency ω _m of the mass member 21 beyond the predetermined frequency (critical frequency ω ₁ ), the effective orifice length La La gradually begins to become shorter. In the middle and high frequency range exceeding the resonance frequency ω _m of the mass member 21, the effective orifice length La is rapidly shortened, and in the frequency range higher than a predetermined frequency (stable frequency ω ₂ ), the effective orifice length La is almost constant. Transition to the shortest length L1. The critical frequency ω ₁ is set to a frequency almost equal to the maximum loss factor frequency ω _L.

It has been found that the frequency of liquid resonance in the orifice 19 rises in inverse proportion to the effective orifice length La. Therefore, the dynamic spring constant Kd is maximized at a slightly higher frequency than the maximum loss factor frequency omega _L, the higher frequency range than the maximum loss factor frequency omega _L (critical frequency omega _1), the effective orifice length La
The frequency at which the orifice 19 causes the stick increases by the amount of shortening, and the dynamic spring constant Kd becomes lower than the conventional dynamic spring constant Kd0. That is, it is possible to increase the frequency at which the orifice 19 causes the stick in the middle and high frequency regions, and to reduce the dynamic spring constant Kd due to the stick.

When a predetermined frequency (limit frequency ω ₂ ) higher than the stable frequency ω ₂ is reached, the orifice 19 sticks. Therefore, above the limit frequency ω ₂ ,
The dynamic spring constant Kd matches the conventional dynamic spring constant Kd0.

As described above, according to this embodiment, by reducing the effective orifice length La with respect to large-amplitude vibrations of medium and high frequencies, the frequency that causes sticking is increased,
The dynamic spring constant can be reduced.

Further, the reduction of the damping force due to the backlash mechanism does not occur, and the increase of the dynamic spring constant with respect to the low frequency vibration due to the inertial force of the resonating mass member 21 can be suppressed.

Therefore, with a simple structure in which the mass member 21 is elastically supported by the leaf spring 35, both a high loss factor and a low dynamic spring of the fluid mount 1 can be achieved at the same time. It is possible to reliably absorb the low-frequency large-amplitude vibration input from the engine and the high-frequency small-amplitude vibration input from the road surface, and obtain a good vibration damping effect.

Next, the second aspect of the present invention according to claim 10
An embodiment will be described with reference to the drawings. FIG. 8 is an enlarged perspective view of an essential part of this embodiment, and corresponds to FIG. 3 of the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

This fluid mount 43, as shown in FIG.
In place of the leaf spring 35 of the first embodiment, the upper and lower coil-shaped springs 45 and 47 elastically support the mass member 21.

The upper and lower springs 45, 47 are formed to have a diameter larger than that of the communication hole 17, and the upper and lower end surfaces 21a, 21b of the mass member 21 are formed with a communication hole at a predetermined distance from the upper and lower end surfaces 21a, 21b. Upper and lower end surfaces 33 of the portion 33
a disk-shaped elastic body supporting portions 49, 51 facing a, 33b
Is protruding. One ends of the springs 45 and 47 are provided with groove portions 53 and 5 formed in the upper and lower elastic body support portions 49 and 51.
5, the other end of the communication hole forming portion 33 has upper and lower end surfaces 33.
It engages with notches 57 and 59 formed on the outer peripheral sides of a and 33b. As a result, the mass member 21 is elastically supported by the upper and lower springs 45 and 47. With no external force applied to the mass member 21, the upper and lower end faces 21a and 21b of the mass member 21 substantially coincide with the upper and lower end faces 33a and 33b of the communication hole forming portion 33. Elastic support 4
Through holes 53 and 55 are provided in the holes 9 and 51 so as not to obstruct the flow of the fluid passing through the orifice 19.

According to the present embodiment, in addition to the effects of the first embodiment, since the mass member 21 is elastically supported by the springs 45 and 47, the displaceable range of the mass member 21 can be increased. That is, the amount of protrusion of the mass member 21 at the maximum amplitude is larger than that in the first embodiment, and the distance Lm between the upper and lower end faces 33a and 33b of the communication hole forming portion 33 and the lower upper end faces 21b and 21a of the mass member (Fig. 5)), the effective orifice length La
(See FIG. 6) can be shortened, and the dynamic spring constant can be further greatly reduced in the frequency range exceeding the resonance frequency of the mass member 21.

Next, the third aspect of the present invention according to claim 11
An embodiment will be described with reference to the drawings. FIG. 9 is an enlarged perspective view of an essential part of this embodiment, which corresponds to FIG. 3 of the first embodiment and FIG. 8 of the second embodiment, respectively. The same parts as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

This fluid mount 43, as shown in FIG.
In place of the leaf spring 35 of the first embodiment and the springs 45 and 47 of the second embodiment, the mass member 21 is elastically supported by two upper and lower rubber members 63 and 65, and another configuration is used. Is the same as in the second embodiment.

According to this embodiment, in addition to the effects of the first embodiment, since the mass member 21 is elastically supported by the rubbers 63 and 65, the generation of vibration noise due to the vibration of the mass member 21 is suppressed. You can

Next, a fourth embodiment according to the invention of claim 4 or 5 will be described with reference to the drawings. FIG. 10 is an enlarged perspective view of an essential part of this embodiment, and corresponds to FIG. 3 of the first embodiment and FIG. 8 of the second embodiment. FIG. 11 is a perspective view of the mass member, and FIG. 12 is a cross-sectional perspective view of a main part of the communication hole forming member. The same parts as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIGS. 10 to 12, the fluid mount 67 includes the outer peripheral surface 37 of the mass member 21 and the communication hole 17.
The inner surface 17a and the inner groove 17 are provided with a spiral inner groove portion 69 and an outer groove portion 71, respectively, which form an orifice so that the effective orifice diameter depends on the frequency.

Similar to the second embodiment, the mass member 21 is elastically supported by the upper and lower two springs 45 and 47 so that the resonance frequency becomes smaller than the maximum loss factor frequency, and the outer diameter of the mass member 21 is the communicating hole. It is formed to be slightly smaller than the hole diameter of 17. That is, the mass member 21
Between the outer peripheral surface 37 and the inner surface 17a of the communication hole 17, there is only a very small gap that allows relative movement between the two.

The inner groove portion 69 and the outer groove portion 71 are formed at substantially the same pitch so as to face each other substantially when the mass member 21 is not vibrating. This pitch is set to a pitch shorter than the maximum amplitude of the mass member.

Both ends 69a and 69b of the inner groove portion 69 are opened to directly communicate the first fluid chamber 11 and the second fluid chamber 13. On the other hand, the outer groove portion 71 is provided in the first fluid chamber 1
The inner groove portion 69 does not directly communicate with the first fluid chamber 13 and the second fluid chamber 13.
The first fluid chamber 11 and the second fluid chamber are communicated with each other via the inner groove portion 69 at a position opposed to. The depth d1 of the inner groove portion 69 and the depth d2 of the outer groove portion 71 are formed at substantially the same depth.

Next, the operation will be described.

When the composite vibration including the resonance frequency of the mass member 21 is input, the mass member 21 resonates and vibrates, and the inner groove portion 69 moves up and down in the vibration direction according to the displacement of the mass member 21. At this time, since the outer groove portion 71 has a pitch shorter than the maximum amplitude of the mass member 21, the inner groove portion 69 will not move during the one vibration of the mass member 21.
Be sure to move to the position opposite to the position opposite to. The orifice diameter formed by the inner groove portion 69 and the outer groove portion 71 is such that the inner groove portion 69 and the outer groove portion 71 are located at positions where they face each other.
Is the maximum diameter (d1 + d2), and the minimum diameter (d1) of only the inner groove portion 69 at the position where they are displaced. In this embodiment, both depths d1 of the inner groove portion 69 and the outer groove portion 71 are
, D2 are formed to be substantially equal, the maximum orifice diameter is approximately twice the minimum orifice diameter.

In the low frequency range lower than the resonance frequency of the mass member 21, when the mass member 21 vibrating at a high frequency is seen from the fluid vibrating at a low frequency, the mass member 21 appears to vibrate at a high speed. Only 69 is present, and the effective orifice diameter is the inner groove 6
The minimum diameter is almost equal to the depth d1 of 9.

On the other hand, in the middle and high frequency range exceeding the resonance frequency of the mass member 21, when the movement of the mass member 21 from the fluid is observed, it seems that the mass member 21 is slowly vibrating. Therefore, the orifice diameter becomes maximum when the inner groove portion 69 and the outer groove portion 71 face each other, and becomes minimum when the inner groove portion 69 is displaced from the outer groove portion 71, but the time-averaged effective orifice diameter is the inner groove portion. 69 depth d1
Will be larger than.

It has been found that the frequency of liquid resonance in the orifice rises in proportion to the effective orifice diameter. Therefore, in the medium and high frequency range, only the effective orifice diameter is appropriately increased and the frequency at which the orifice sticks increases, so that the dynamic spring constant due to the sticking of the orifice can be reduced.

13A shows a vibration model of the mass member 21, and FIGS. 13B and 13C show changes in the fluid pressure of the fluid vibrating at the resonance frequency of the mass member 21,
It shows the relationship with the displacement of the mass member.

As shown in FIGS. 13B and 13C, particularly at the resonance frequency of the mass member 21, the mass member 21 is displaced by 90 ° with respect to the fluid pressure of the fluid. Therefore, when the hydraulic pressure of the fluid becomes maximum, the displacement of the mass member 21 becomes 0 and the orifice diameter becomes maximum. That is, the mass member 2
At the resonance frequency of 1, the orifice diameter becomes maximum when the fluid pressure of the fluid becomes maximum, and the fluid easily flows through the orifice, so that the frequency at which the orifice sticks can be further increased, and The resulting dynamic spring constant can be reduced more effectively.

As described above, according to this embodiment, by increasing the effective orifice diameter for large amplitude vibrations of medium and high frequencies, the frequency of sticking can be increased and the dynamic spring constant can be reduced. it can.

As in the first embodiment, the damping force is not reduced due to the backlash mechanism, and the increase of the dynamic spring constant due to the low frequency vibration due to the inertial force of the resonating mass member 21 is suppressed. be able to.

Therefore, it is possible to increase only the effective orifice diameter with a simple structure to achieve both a high loss factor and a low dynamic spring of the fluid mount 67.

Next, the fifth aspect of the present invention according to claim 13
An embodiment will be described with reference to the drawings. FIG. 14 is a cross-sectional view of this embodiment, and the same parts as those of the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

The fluid mount 73 is obtained by applying the second embodiment to the member insulator.

As shown in FIG. 14, this fluid mount 7
3 is a first fixing portion 75, a second fixing portion 77, an elastic body 79, a partition portion 81, a fluid chamber 9, a communication hole 17,
And a mass member 21.

The first fixing portion 75 is formed in a cylindrical shape,
It is connected to the rear suspension member side as a vehicle body member. The second fixing portion 77 has a cylindrical shape coaxially provided outside the first fixing portion 75, and is connected to the rear side member side as a vehicle body member. The partition portion 81 is formed in a plate shape and is fixed to the second fixing portion 77. Elastic body fixing portions 83 extend from both ends of the partition portion 81 along the inner peripheral surface of the second fixing portion 77. The elastic body 79 is
The outer peripheral surface of the first fixing portion and the outer surface of the elastic body fixing portion are vulcanized and adhered to elastically connect the two fixing portions 75 and 77. The elastic body 79 is provided between the two fixing portions 75 and 77, and has a fluid chamber 9 filled with a fluid therein, which is vertically arranged in the drawing.
It is divided into two spaces. The two spaces are the gap 8 formed between the second fixing portion 77 and the elastic body fixing portion 83.
A partition part 81 is provided in one of the two spaces (downward in the drawing) to communicate with each other by 5.

The partition 81 partitions one space into the first fluid chamber 11 and the second fluid chamber 13, and the other space serves as the second fluid chamber 13. Similar to the second embodiment, the partition portion 81 is provided with the communication hole forming portion 33 that forms the communication hole 17, and the mass member 21 that forms the orifice between the communication hole 17 and the inner surface 17a is the upper and lower springs. Four
It is elastically supported by 5, 47.

The resonance frequency of the mass member 21 is set higher than the maximum loss factor frequency, and the maximum loss factor frequency is set to the resonance frequency of the rear suspension.

According to this embodiment, at the resonance frequency of the rear suspension member, the damping force caused by the backlash mechanism does not decrease, and a sufficient damping force can be obtained, which is effective in a high frequency region such as road noise. Since the orifice length becomes shorter and the orifice does not easily stick, the dynamic spring constant can be reduced. That is, when the vehicle is traveling, it is possible to reliably absorb the vibration input from the road surface and obtain a good vibration damping effect.

Next, a sixth embodiment according to the invention of claim 7 or 8 will be described with reference to the drawings. FIG. 15 is a perspective view of a cross section of a main part of this embodiment, FIG. 16 is a schematic view showing the vibration model of FIG. 15, FIG. 17 is an overall cross sectional view of this embodiment, and FIG.
8 is a characteristic diagram of the fluid mount of FIG. 15 with respect to the frequency of the input vibration, (a) is a relationship diagram of the frequency of the input vibration and the dynamic spring constant and loss factor, and (b) is the frequency of the input vibration and the vibrating member. FIG. 6 is a relational diagram with displacement of the mass member.
The same parts as those in the second and fifth embodiments are designated by the same reference numerals and the description thereof will be omitted.

The fluid mount 73 forms a two-degree-of-freedom vibration system by elastically supporting the mass member 21 on the vibrating member 89.

As shown in FIG. 15, a hole 81a is formed in the partition 81, and a vibrating member 89 is provided in the hole 81a. The vibrating member 89 is elastically supported by the partition 81 fixed to the second fixing portion 77 by the rubber member 91, and the rubber member 91 closes the gap between the partition 81 and the vibrating member 89. Similar to the second embodiment, the vibrating member 89 is provided with a communication hole forming portion 33 that forms the communication hole 17, and the mass member 21 that forms the orifice 19 between the inner surface 17a of the communication hole 17 and the mass member 21. Upper and lower springs 45, 47
It is elastically supported by. As a result, the mass member 2
1, the springs 45 and 47, the vibrating member 89, and the rubber member 91 form a two-degree-of-freedom vibration system. In addition, FIG.
As shown in FIG. 11, the fluid mount 87 is a member insulator as in the fifth embodiment.

The support elastic constant of the vibrating member 89 by the rubber member 91 is the same as that of the mass member 21 by the springs 45 and 47.
Is set smaller than the supporting elastic constant of. As a result, as shown in FIG. 18B, the vibrating member 89 and the mass member 21 resonate at two resonance frequencies ω ₁₁ and ω ₁₂ on the low frequency side and the high frequency side, and both resonance frequencies ω ₁₁ until inversion frequency omega ₁₃ between omega ₁₂ both displaced in phase inverted at the inverted frequency omega _13. Displacement between the fluid and the cuff member 89, until the resonance frequency omega ₁₁ of the low-frequency side phase, reverse phase from the resonant frequency omega ₁₁ of the low-frequency side to the inverting frequency omega _13,
The inversion frequency ω ₁₃ to the resonance frequency ω ₁₂ on the high frequency side are in phase, and the resonance frequency ω ₁₂ on the high frequency side and above are in reverse phase. Further, as shown in FIG. 18A, the resonance frequencies ω ₁₁ and ω ₁₂
Indicates that the maximum loss factor frequency ω _{L at} which the loss factor LF1 is maximum is included in the frequency range in which the vibrating member 89 and the mass member 21 are displaced in the same phase and the vibrating member 89 and the fluid are displaced in the opposite phase. Is set. In this embodiment, the maximum loss factor frequency ω _L is set to the resonance frequency of the rear suspension member and is substantially equal to the resonance frequency ω ₁₁ on the low frequency side.

Next, the operation of this embodiment will be described with reference to FIG.

Low frequency range (first
In the frequency range of 1), since the reversal frequency ω ₁₃ is lower, the vibrating member 89 and the mass member 21 are displaced in phase. Therefore, the orifice length does not fluctuate and becomes almost constant. In addition,
The orifice diameter is almost constant as in the first embodiment.

Further, the displacement of the fluid and the vibrating member 89 are in the same phase, and the fluctuation of the fluid pressure of the fluid is absorbed by the vibrating member 89, so that the rise of the fluid pressure is suppressed and the fluid flowing through the orifice 19 is reduced. . Therefore, in this low frequency range, the dynamic spring constant Kd1 can be further reduced than the dynamic spring constant Kd of the first embodiment.

At the resonance frequency of the rear suspension, the vibrating member 89 and the mass member 21 are displaced in the same phase, and the vibrating member 89 and the fluid are displaced in the opposite phase, so that the orifice length and the orifice diameter do not change. Moreover, the loss factor becomes maximum when the vibrating member 89 is displaced in a phase opposite to the hydraulic pressure of the fluid. Therefore, the loss factor can be more effectively increased by utilizing the effect on the hydraulic pressure, and a maximum value larger than the loss factor LF of the first embodiment can be obtained.

High frequency range (second
In the frequency range of), since the reversal frequency ω ₁₃ is exceeded,
The vibrating member 89 and the mass member 21 are displaced in opposite phases. For this reason, the shape of the orifice 19 largely changes according to the displacement of the mass member 21, and when the movement of the mass member 21 is observed from the fluid, the mass member 21 seems to be slowly vibrating. Therefore, the effective orifice length in the second frequency range is shorter than that in the first frequency range.

As a result, similarly to the first embodiment, the frequency at which the orifice 19 causes sticking can be increased in the high frequency range, and the dynamic spring constant due to sticking of the orifice 19 can be reduced. .

Further, in the high frequency range, the vibrating member 89
Since the mass member 21 and the mass member 21 are displaced in opposite phases and the shape of the orifice 19 is largely changed according to the displacement of the mass member 21, the effective orifice length can be further effectively reduced as compared with the first embodiment. Therefore, the dynamic spring constant Kd1 caused by the stick of the orifice 19 can be further effectively reduced.

Further, from the inversion frequency ω ₁₃ to the resonance frequency ω ₁₂ on the high frequency side, the displacements of the vibrating member 89 and the mass member 21 are in the same phase, and the fluid pressure of the fluid is absorbed by the vibrating member 89. Since the pressure rise is suppressed, the dynamic spring constant Kd1 can be further reduced in this frequency range.

As described above, according to this embodiment, as in the first embodiment, by shortening the effective orifice length against high frequency vibration, the frequency that causes sticking is increased and the dynamic spring constant is reduced. In addition, the damping force due to the backlash mechanism does not decrease, and the increase of the dynamic spring constant for low frequency vibration due to the inertial force of the resonating mass member 21 can be suppressed.

Further, since the vibration system has two degrees of freedom, since the vibrating member 89 absorbs the fluid pressure fluctuation of the fluid in the low frequency range, the dynamic spring constant Kd1 can be further reduced. At the resonance frequency of the rear suspension, the vibrating member 8
Since 9 is displaced in the opposite phase to the fluid pressure of the fluid, the effect on the fluid pressure can be utilized to more effectively increase the loss factor. Further, in the high frequency range, the shape of the orifice 19 varies more greatly according to the displacement of the mass member 21, so that the effective orifice length can be further effectively reduced, and the resonance from the reversal frequency ω ₁₃ to the high frequency side can be further reduced. Up to the frequency ω ₁₂ , the vibrating member 89 absorbs the fluid pressure of the fluid, so that the dynamic spring constant Kd 1 can be further reduced.

Therefore, it is possible to achieve both a low dynamic spring constant over the entire frequency range and a high loss factor at a desired frequency, and to ensure that vibrations input from the road surface during vehicle running. By absorbing, a good vibration damping effect can be obtained.

Further, the fluid mount 87 is used as an engine mount, a leaf spring or rubber is used in place of the springs 45 and 47, and an orifice is formed by an inner groove portion of the mass member 21 and an outer groove portion of the communication hole 17. With the configuration, the same operational effects as those of the first to sixth embodiments can be obtained.

[0135]

As described above, according to the invention described in claim 1, since the mass body forming the orifice with the inner surface of the communication hole is elastically supported, the shape of the orifice changes with time. The frequency range that fluctuates and exceeds the resonance frequency of the mass body has a shorter effective orifice length or a larger effective orifice diameter than the frequency range that is smaller than the resonance frequency of the mass body. In the frequency range beyond the limit, the frequency at which the orifice causes sticking can be substantially increased, and the dynamic spring constant due to the sticking of the orifice can be reduced.

Further, since the damping force is not reduced due to the backlash mechanism and the mass body is used to form the orifice, it does not require weight and is caused by the inertial force of the resonating mass body. There is no increase in the dynamic spring constant.

Therefore, both high loss factor and low dynamic spring can be achieved at the same time, and a good vibration damping effect can be obtained.

According to the invention of claim 2, claim 1
In addition to the effect of the invention described in (1), the orifice is a gap formed along the hole direction of the communication hole, and the mass body vibrates along the hole direction of the communication hole, so only the effective orifice length has a simple structure. Can be accurately reduced.

According to the invention of claim 3, claim 2
In addition to the effect of the invention described in (1), since the upper and lower ends of the mass body in the vibration direction substantially coincide with the upper and lower ends of the communication hole when the mass body is not vibrating, the maximum effective orifice length of the communication hole is It is regulated by the length between the upper and lower ends, and in the frequency range lower than the resonance frequency of the mass body, the effective orifice length can be made almost constant, and in the frequency range exceeding the resonance frequency of the mass body, The effective orifice length can be reduced more accurately.

According to the invention of claim 4, claim 1
In addition to the effects of the invention described in (1), the orifice is an inner groove portion formed on the outer surface of the mass body and an outer groove portion formed on the inner surface of the communication hole, and the mass body vibrates along the hole direction of the communication hole. Therefore, only the effective orifice diameter can be accurately increased with a simple structure.

According to the invention of claim 5, claim 4
In addition to the effects of the invention described in (1), at the resonance frequency of the mass body, the mass body is displaced by 90 ° with respect to the fluid pressure of the fluid, so that at the resonance frequency of the mass body, the fluid pressure of the fluid is When this happens, the diameter of the orifice becomes maximum, the fluid easily flows through the orifice, the frequency at which the orifice causes sticking can be further increased, and the dynamic spring constant due to the sticking of the orifice can be reduced more effectively. it can.

According to the invention described in claim 6, claim 1
In addition to the effect of the invention according to any one of claims 5 to 5, since the resonance frequency of the mass body is higher than the maximum loss factor frequency, the maximum loss factor frequency is set in a frequency range with a large amplitude to increase the damping force. In addition, the dynamic spring constant can be reduced in the frequency range higher than the maximum loss factor frequency. Therefore, it is possible to simultaneously realize a high loss factor at a frequency where attenuation is desired to be increased and a low dynamic spring in the entire frequency range.

According to the invention of claim 7, claim 1
In addition to the effect of the invention according to any one of claims 6 to 6, in the frequency range in which the vibrating member and the mass body are displaced in opposite phases,
Since the shape of the orifice fluctuates more greatly according to the displacement of the mass body, the effective orifice length can be reduced or the effective orifice diameter can be increased more effectively, and the dynamic spring constant due to the stick of the orifice can be further improved. Can be reduced.

Further, in the frequency range lower than the resonance frequency on the low frequency side, the displacement of the fluid and the vibrating member are in phase, and the fluctuation of the fluid pressure of the fluid is absorbed by the vibrating member. As a result, the fluid flowing through the orifice is reduced. Therefore, the dynamic spring constant can be further reduced in this frequency range.

Further, in the frequency range from the inversion frequency to the resonance frequency on the high frequency side, the displacement of the vibrating member and the mass body are in the same phase, and the fluid pressure of the fluid is absorbed by the vibrating member. Thus, the dynamic spring constant can be further reduced in this frequency range.

Therefore, both high loss factor and low dynamic spring can be achieved at the same time, and a further excellent vibration damping effect can be obtained.

According to the invention described in claim 8, claim 7 is provided.
In addition to the effect of the invention described in (1), the loss factor becomes maximum when the orifice length and the orifice diameter do not change and the vibrating member is displaced in a phase opposite to the hydraulic pressure of the fluid,
The loss factor can be increased more effectively by utilizing the reaction force against the hydraulic pressure, and the high loss factor at the frequency where attenuation is desired to be increased and the low dynamic spring in the entire frequency range are more effective. Can be realized.

According to the invention of claim 9, claim 1
In addition to the effect of the invention described in any one of claims 8 to 8, since the mass body is elastically supported by the leaf spring, a simple structure can be obtained.

According to the invention of claim 10, in addition to the effects of the invention of any one of claims 1 to 8,
Since the mass body is elastically supported by the coil spring, the movable range of the mass body can be increased, and the effective orifice length can be shortened or the effective orifice diameter can be increased accordingly. Therefore, the dynamic spring constant can be further reduced.

According to the invention of claim 11, in addition to the effects of the invention of any one of claims 1 to 8,
Since the mass body is elastically supported by the rubber member, generation of vibration noise of the mass body can be suppressed.

According to the twelfth aspect of the invention, in addition to the effects of the first aspect of the invention, one of the two fixing portions is connected to the power unit side,
The other was connected to the vehicle body side and this fluid mount was used as an engine mount.Therefore, when the vehicle was running, there were low-frequency large-amplitude vibrations of the engine caused by input from the road surface and high-frequency small-amplitude vibrations due to the engine excitation force. Can be reliably absorbed, and a good vibration damping effect can be obtained.

According to the thirteenth aspect of the invention, in addition to the effects of the invention according to any of the first to eleventh aspects, the two fixing portions are respectively connected to the vehicle body member, and the fluid mount is mounted. Since it is used as the member insulator, it is possible to reliably absorb the vibration input from the road surface while the vehicle is traveling, and it is possible to obtain a good vibration damping effect.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged perspective view of a B part in FIG.

FIG. 4 is an enlarged schematic diagram showing an effective orifice length for low frequency vibration.

FIG. 5 is an enlarged schematic diagram illustrating a state of a mass member with respect to high frequency vibration.

FIG. 6 is an enlarged schematic diagram showing an effective orifice length for high frequency vibration.

7A and 7B are characteristic diagrams of the fluid mount of FIG. 1 with respect to the frequency of the input vibration, where FIG. 7A is a relationship diagram between the frequency of the input vibration and the dynamic spring constant and loss factor, and FIG. FIG. 3C is a relationship diagram with the orifice length, and FIG. 7C is a relationship diagram with the frequency of the input vibration and the displacement of the mass member.

FIG. 8 is an enlarged perspective view of a main part of the second embodiment of the present invention.

FIG. 9 is an enlarged perspective view of an essential part of the third embodiment of the present invention.

FIG. 10 is an enlarged perspective view of essential parts of a fourth embodiment of the present invention.

FIG. 11 is a perspective view of a mass member.

FIG. 12 is a cross-sectional perspective view of a main part of a communication hole forming member.

13A and 13B are explanatory views of the operation of the fourth embodiment, where FIG. 13A is a schematic diagram showing a vibration model of a mass member, and FIGS. 13B and 13C are hydraulic pressure changes of a fluid vibrating at the resonance frequency of the mass member. And the displacement of the mass member.

FIG. 14 is a sectional view of a fifth embodiment of the present invention.

FIG. 15 is a cross-sectional perspective view of a main part of a sixth embodiment of the present invention.

16 is a schematic diagram showing the vibration model of FIG.

FIG. 17 is an overall sectional view of the present embodiment.

FIG. 18 is a characteristic diagram of the fluid mount shown in FIG. 15 with respect to the frequency of the input vibration, (a) is a relationship diagram of the frequency of the input vibration and the dynamic spring constant and loss factor, and (b) is the frequency of the input vibration. It is a relationship diagram with displacement of a vibration member and a mass member. It is an expansion schematic diagram which shows the effective orifice length with respect to a high frequency vibration.

FIG. 19 is a cross-sectional view showing a conventional example.

FIG. 20 is a cross-sectional view showing another conventional example.

FIG. 21 is a cross-sectional view showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid mount 3 1st fixing | fixed part 5 2nd fixing | fixed part 7 Elastic body 11 1st fluid chamber 13 2nd fluid chamber 15 Partition part 17 Communication hole 17a Inner surface of communication hole 19 Orifice 21 Mass member (mass body) 21a Upper end surface of mass member (upper end portion of mass body) 21b Lower end surface of mass member (lower end portion of mass body) 33a Upper end surface of communication hole forming member (upper end portion of communication hole) 33b Lower end surface of communication hole forming member ( Lower end of communication hole) 35 leaf spring 43 fluid mount 45 spring 47 spring 61 fluid mount 63 rubber (rubber member) 65 rubber (rubber member) 67 fluid mount 69 inner groove portion 71 outer groove portion 73 fluid mount 75 first fixing portion 77 Second fixed part 79 Elastic body 81 Partition part 87 Fluid mount 89 Vibrating member La Effective orifice length Kd Dynamic spring constant Kd1 Dynamic spring constant Number LF Loss factor LF1 Loss factor

Claims (13)

[Claims] 1. An elastic body for elastically connecting two fixing parts, two fluid chambers provided between the two fixing parts and filled with a fluid, and a communication between the two fluid chambers. And a mass body that is elastically supported by the communication hole and that forms an orifice between the communication hole and an inner surface of the communication hole. 2. The fluid mount according to claim 1, wherein the orifice is a gap between an inner surface of the communication hole formed along a hole direction of the communication hole and an outer surface of the mass body, The fluid mount, wherein the mass body vibrates along a hole direction of the communication hole. 3. The fluid mount according to claim 2, wherein upper and lower end portions of the mass body in a vibration direction substantially coincide with upper and lower end portions of the communication hole when the mass body is not vibrated. A fluid mount featuring. 4. The fluid mount according to claim 1, wherein the orifice is formed in an outer surface of the mass body, and has a spiral inner groove portion that communicates the first fluid chamber and the second fluid chamber. And the first fluid chamber and the first fluid chamber are formed on the inner surface of the communication hole and do not directly communicate with the first fluid chamber and the second fluid chamber, but face the inner groove portion and the first fluid chamber through the inner groove portion. A spiral outer groove communicating with the second fluid chamber and having a pitch shorter than the maximum amplitude of the mass body, wherein the mass body vibrates in the hole direction of the communication hole. Fluid mount. 5. The fluid mount according to claim 4, wherein the inner groove portion and the outer groove portion substantially face each other when the mass body is not vibrating and face each other. 6. The fluid mount according to claim 1, wherein a resonance frequency of the mass body is set higher than a maximum loss factor frequency. 7. The fluid mount according to claim 1, wherein the communication hole is provided in a vibrating member elastically supported so as to be vibrable with respect to one of the fixing portions, The support elastic constant between the one fixed portion and the vibrating member is
A fluid mount characterized by being set to be smaller than a support elastic constant between the vibrating member and the mass body. 8. The fluid mount according to claim 7, wherein the resonance frequency of the mass body is such that the mass body and the vibrating member are displaced in phase, and the vibrating member and the fluid are opposite to each other. A fluid mount characterized by being set so that the maximum loss factor frequency is included in the frequency range in which the phase is displaced. 9. The fluid mount according to claim 1, wherein the mass body is elastically supported by a leaf spring. 10. The fluid mount according to claim 1, wherein the mass body is elastically supported by a coil spring. 11. The fluid mount according to claim 1, wherein the mass body is elastically supported by a rubber member. 12. The fluid mount according to claim 1, wherein one of the two fixing portions is connected to a power unit side,
The other is a fluid mount that is connected to the vehicle body side. 13. The fluid mount according to claim 1, wherein the two fixing portions are respectively connected to a vehicle body member.