JPH10246276A - Liquid-sealed vibration isolating mount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid-sealed vibration isolating mount which obtains a vibration isolating effect in two or more mutually different frequency regions by a simple structure. SOLUTION: In a lower side from an inner cylinder 1, a main fluid chamber 5 is provided, between a recessed part 4b and an outer cylinder 2, a partition wall 8 is provided, a first/second sub fluid chamber 6, 7 is formed, in an upper side of the inner cylinder, a through space 8 is provided, the through space and each sub fluid chamber are partitioned by a cylinder wall of the recessed part of an intermediate cylinder. Relating to the main fluid chamber, the first sub fluid chamber is made to communicate by a first orifice 9 of thin width, the second sub fluid chamber is made to communicate by a second orifice 10 of wide width. Each sub fluid chamber is sealed with liquid 12 and air 13, a second air chamber part 7b sealed with air is set to a small capacity compressed, when low frequency vibration is input, so as to limit a flow of fluid through the second orifice. A communication hole 8a is provided in the partitioning wall, by setting a hole diameter, at stationary time, liquid circulation between both the sub fluid chambers is permitted, to automatically correct an air amount of each air chamber part 6b, 7b, at vibration input time, so as to substantially interrupt liquid circulation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bush type liquid-filled anti-vibration mount for supporting, for example, an engine of an automobile.

[0002]

2. Description of the Related Art Conventionally, as this type of liquid-filled anti-vibration mount, first to third three liquid chambers are formed in an elastic body in order to achieve anti-vibration in two different frequency ranges. , First
It is known that two vibration systems are formed by connecting a second liquid chamber to a liquid chamber via a first orifice and communicating a third liquid chamber via a second orifice (for example, See JP-A-1-126451). In this device, the first liquid chamber is disposed at a lower position of the inner cylinder, and the second and third liquid chambers are disposed at both left and right positions of the inner cylinder.
The orifice is formed to have a small cross-sectional area and to extend substantially all around the outer cylinder body to increase the passage length, while the second orifice has a large cross-sectional area and a shortest length. .

In order to expand and contract the sub liquid chamber into which the liquid from the main liquid chamber flows through the orifice, a part of the sub liquid chamber is usually constituted by a diaphragm. For the purpose of omitting the diaphragm, air is enclosed in the sub-liquid chamber in addition to the liquid, and the volume of the liquid part in the sub-liquid chamber is expanded and contracted by utilizing the compression / expansion action of the air part. Such a configuration is also known (for example, JP-A-7-151183).

[0004]

However, in the liquid-filled vibration-proof mount having the above-mentioned three liquid chambers,
Since it is necessary to form a rebound-side stopper above the inner cylinder, the second and third liquid chambers must be formed symmetrically on the left and right. In order to generate a peak of the loss coefficient (tan δ) in the frequency range, it is necessary to make the orifice of one of the vibration systems sufficiently long, and conversely, to generate the bottom of the dynamic spring constant in the high frequency range, The orifice of the system must be wide enough. In other words, the structure on the side of the second and third liquid chambers should be the same, and the structure on the side of the orifice should be devised such that one orifice is narrow and long, and the other orifice is wide and short. For this reason, the one orifice has to be formed over substantially the entire circumference at the inner peripheral side position of the outer cylindrical body, resulting in a complicated structure and an increase in the number of processing steps. .

In order to expand and contract the second and third liquid chambers, a part of each liquid chamber is formed as a diaphragm.
When the liquid flows into the second or third liquid chamber, the inner cylinder body is displaced downward so as to change the volume of the first liquid chamber to the reduction side. Tensile force is acting according to the displacement of the cylinder.
In addition, not only does the function of enlarging the third liquid chamber not work effectively, it is not possible to sufficiently secure the inflow of liquid from the first liquid chamber side, but also the second and third liquids in the two vibration systems. Nor can the stiffness of each diaphragm in the chamber be adjusted according to the resonance frequency of the two orifices.

On the other hand, in order to omit the diaphragm formed facing a part of the second and third liquid chambers, it is conceivable to enclose air in addition to the liquid. However, the diaphragm is an inner cylindrical body. The diaphragm portion cannot be made rigid originally, and therefore, there is no point in enclosing the air.

[0007] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid-filled type anti-vibration device having a simple structure and capable of obtaining anti-vibration effects in two or more different frequency ranges. To provide a swing mount.

[0008]

In order to achieve the above object, an invention according to claim 1 comprises an inner cylinder having a cylinder axis arranged laterally, and an outer cylinder surrounding the inner cylinder. An elastic body connecting the outer cylinder and the inner cylinder to each other, a main fluid chamber defined in the lower elastic body of the inner cylinder, and an elastic body at an upper position of the inner cylinder. A sub-fluid chamber defined in the body,
It is assumed that a liquid-filled anti-vibration mount including liquid sealed in the main fluid chamber and the sub-fluid chamber and an orifice communicating the two fluid chambers with each other is provided. In this case, two or more sub-fluid chambers are formed independently of each other, and these two or more sub-fluid chambers and the main fluid chamber are individually communicated via different orifices. Further, gas is sealed in the upper part of each of the two or more sub-fluid chambers, and liquid is sealed in each of the sub-fluid chambers such that the liquid surface is located above the sub-fluid chamber side opening of each of the orifices. The orifices are set so that liquid column resonance occurs in different frequency ranges, and the set resonance frequency of the orifice that communicates the gas portion of each of the sub-fluid chambers with each of the sub-fluid chambers is on the low frequency side. In this configuration, the volume on the high frequency side is set smaller than that on the high frequency side.

In the above configuration, two or more vibration systems are formed by the main fluid chamber and the individual sub-fluid chambers connected to the main fluid chamber by individual orifices, and each of the orifices is set. Liquid column resonance occurs in each resonance frequency range. For this reason, if there are two sub-fluid chambers, an anti-vibration effect in two different frequency ranges is obtained,
If the number of sub-fluid chambers is three, vibration-damping effects can be obtained in three different frequency ranges.

In addition, the volume of gas sealed in each sub-fluid chamber is smaller when the orifice communicating with the sub-fluid chamber has a high resonance frequency than when the resonance frequency is low. Therefore, the degree of compression (rigidity) of the gas portion in each of the sub-fluid chambers when the liquid flows from the main fluid chamber through the orifice connected to the sub-fluid chambers.
Will be different from each other in the individual sub-fluid chambers. Therefore, even when vibration in the low-frequency range is input, the gas portion of the sub-fluid chamber to which the orifice on the high-frequency side communicates is compressed earlier, and the inflow of liquid into the sub-fluid chamber is suppressed. As a result, the flow amount of the liquid to the orifice on the low frequency side is secured more, and the liquid column resonance in the low frequency region is effectively exhibited. That is, when vibration in the low frequency range is input, the liquid flows through the orifice whose resonance frequency is set to the low frequency side and the orifice whose resonance frequency is set to the high frequency side. The gas flowing in the sub-fluid chamber is compressed more quickly by the liquid flowing into the side, and the liquid hardly flows to the orifice on the high-frequency side. As a result, the flow rate of the liquid to the orifice on the low frequency side increases, and the liquid column resonance in the low frequency region through the orifice on the low frequency side is effectively exerted to attenuate the input vibration. become.

According to a second aspect of the present invention, in the first aspect of the present invention, the inner cylinder is provided in an elastic body at an intermediate position between the inner cylinder and the outer cylinder and near the outer cylinder. It is provided with an intermediate cylindrical body embedded so as to surround the periphery, and a through space penetrating through the elastic body closer to each sub-fluid chamber than the inner cylindrical body in parallel with the cylinder axis of the inner cylindrical body. A concave portion is formed in the intermediate cylinder at a position on the side of each of the sub-fluid chambers, and a concave portion is formed on the side of the inner cylinder. In addition, each of the sub-fluid chambers is
The space between the concave portion and the outer cylindrical body is formed by partitioning the cylindrical wall of the concave portion and the outer cylindrical body with each other by a partition wall connecting the outer cylindrical body to the space.

In the case of the above configuration, since the through space is provided, it is possible to cope with a large displacement without excessively increasing the tensile stress acting on the elastic body with respect to a large amplitude vibration input.
In addition, a partition wall for partitioning each sub-fluid chamber and the through space,
Since it is constituted by the cylindrical wall which is a rigid member constituting the concave portion of the intermediate cylindrical body, the strength is increased as compared with the conventional case where it is partitioned by an elastic film member such as a rubber thin film, and a large internal pressure is generated by a large amplitude vibration input. Even if it is received, it is possible to avoid the possibility that the partition wall is damaged. Further, since the two or more sub-fluid chambers are partitioned by the partition wall connecting the cylindrical wall and the outer cylinder body which are the rigid members as described above, each sub-fluid chamber is easily formed to have a predetermined volume. And three or four sub-fluid chambers as well as two can be easily formed.

Further, the invention according to claim 3 is the invention according to claim 1.
Alternatively, in the invention according to claim 2, the partition walls separating the two or more sub-fluid chambers are separated from each other by the gas in each of the sub-fluid chambers in a state where the liquid surfaces of the sub-fluid chambers formed by the partition walls are at the same level as each other. Is formed at a position where a predetermined amount is provided, and a communication hole through which the liquids in the sub-fluid chambers can mutually flow is formed at a position immediately below the liquid level with respect to the partition wall. The communication hole is set to have a diameter and a length at which the flow of the liquid is substantially stopped at the resonance frequency of the orifice that causes liquid column resonance in the lowest frequency band of the plurality of orifices.

In the case of the above configuration, the attitude of the liquid-filled anti-vibration mount, which has been manufactured by filling a predetermined amount of gas, is changed for transporting and assembling to the vehicle, and the filled gas in each sub-fluid chamber is changed. Even if the amount changes, when the sub-fluid chambers are arranged above and the main fluid chamber is arranged below when assembled to the vehicle, the liquid in each sub-fluid chamber moves through the communication hole in this state. Since the liquid level in each sub-fluid chamber is automatically the same, the amount of gas in each sub-fluid chamber is automatically maintained at the initially set amount. In addition, at the resonance frequency where liquid column resonance occurs in the lowest frequency range, the communication hole substantially stops the flow of the liquid, so the rigidity of the gas portion sealed in each sub-fluid chamber is reliably obtained, Thereby, the vibration of the input vibration based on the liquid column resonance of each orifice is reliably prevented.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIGS. 1 to 3 show a liquid-filled anti-vibration mount according to a first embodiment of the present invention.
Are inner cylinders arranged so that the cylinder axis X is substantially horizontal.
Is an outer cylinder disposed on the outer periphery so as to surround the inner cylinder 1, 3 is an elastic body for connecting the outer cylinder 2 and the inner cylinder 1 to each other, and 4 is An intermediate cylinder embedded in the elastic body 3 at a position intermediate to the outer cylinder 2 and close to the outer cylinder 2 so as to surround the inner cylinder 1. Reference numeral 5 denotes a main fluid chamber defined in the lower elastic body 3 of the inner cylinder 1, and reference numerals 6 and 7 denote first and second fluid chambers defined in the upper elastic body 3 of the inner cylinder 1. The second sub-fluid chamber 8 is provided with partition walls 9 and 9 for partitioning the first and second sub-fluid chambers 6 and 7.
Reference numeral 10 denotes first and second orifices for communicating the main fluid chamber 5 and the sub-fluid chambers 6 and 7 with each other, and 11 denotes the inner cylinder 1
It is a through space that passes through the inside of the elastic body 3 above the cylinder axis X for change. A liquid 12 as an incompressible fluid and an air 13 as a compressible gas are sealed in the main fluid chamber 5 and the two sub-fluid chambers 6 and 7. The sub-fluid chamber side openings 9a, 1 of the orifices 9, 10 are vertically intermediate positions of the chambers 6, 7.
It is sealed so that the liquid surface 12a is located at a position above 0a. Thus, the liquid chambers 6a and 7a are formed in the lower half of each of the sub-fluid chambers 6 and 7, while the air chambers 6b and 7b are formed in the upper half. In addition, FIGS.
This shows a state in which the inner cylinder 1 is connected to the vehicle body on the side of the vibration receiving unit, and the outer cylinder 2 is connected to the engine side which is the vibration source, and the weight of the engine acts on the elastic body 3.

The elastic body 3 is formed by vulcanization integrally with the inner cylinder 1 and the intermediate cylinder 4, and has a rubber thin layer 3a (see FIGS. (See FIG. 3), and press-fits into the inner peripheral surface of the outer cylinder 2 to connect the inner cylinder 1 and the outer cylinder 2 to each other. This elastic body 3 supports the inner cylinder 1 in an eccentric state displaced downward relative to the outer cylinder 2 before mounting as an engine mount, and the outer cylinder 2 supports the engine. As a result of bending of the elastic body 3 due to the weight of the engine in the state, FIG.
As shown in FIG. 1, the inner cylinder 1 is positioned and supported coaxially with the intermediate cylinder 4 and the outer cylinder 2 with respect to the cylinder axis X. The lower surface 3b of the elastic body 3 has a central portion 3c in a direction perpendicular to the cylinder axis X and in a horizontal direction (hereinafter, referred to as a left-right direction) protruding downward in a state where the own weight of the engine is applied. With the lower end of the portion 3c as the lowest point, the main fluid chamber side openings 9b,
The lower surface 3b guides a substantially V-shaped cross-sectional shape having an inner angle smaller than 180 degrees between the openings 9b and 10b around the lowermost point. Surface 14 is configured.

As shown in detail in FIG. 4, the lower portion of the outer peripheral surface of the intermediate cylinder 4 is cut out to form a window 4a, and the upper portion is recessed inward to form a recess 4b. Is formed. The main fluid chamber 5 penetrates through the window 4a and is defined by a lower surface 3a of the elastic body 3 and an inner peripheral surface of the outer cylinder 2 opposed to the lower surface 3a. The through space 8 and the sub-fluid chambers 6 and 7 are separated from each other by the cylindrical wall of the intermediate cylindrical body 4 constituting the concave portion 4b.

In addition, the partition wall 8 is integrated with the elastic body 3 so as to connect the concave portion 4b and the inner peripheral surface of the outer cylinder 2 to each other at a position shifted by a predetermined amount from the center position in the left-right direction of the concave portion 4b. The first sub-fluid chamber 6 is defined by one side of the concave portion 4b, one side surface of the partition wall 8, and the inner peripheral surface of the outer cylinder 2 covering the upper side of the concave portion 4b. ,
The second sub-fluid chamber 7 is defined by the other side of the concave portion 4b, the other side surface of the partition wall 8, and the inner peripheral surface of the outer cylinder 2 covering the upper side of the concave portion 4b. The formation position of the partition wall 8 is determined so that the two air chambers 6b and 7b have a predetermined volume when the liquid levels 12a of the two sub-fluid chambers 6 and 7 are at the same level. The volume of the chamber 6b is set to be larger than the volume of the second air chamber 7b. More specifically, the first air chamber 6b has a predetermined large volume (for example, 4 to 10 cc) for realizing rigidity (degree of expansion / compression) for low frequency vibration determined by a relationship with a resonance frequency of a first orifice 9 described later. The volume of the second air chamber portion 7b is set to a predetermined small volume (for example, 1 to 2 cc) for realizing rigidity for high-frequency vibration determined by a relationship with the resonance frequency of the second orifice 10 described later. Thus, the position of the partition wall 8 is determined. In particular, the setting of the amount of air in the second air chamber 7b is controlled by the second orifice 10 when the low-frequency vibration is input.
The flow of the liquid 12 via the first orifice 9 can be restricted so that the flow amount of the liquid 12 on the side of the first orifice 9 can be secured.

In addition, the two sub-fluid chambers 6 are located on the partition wall 8 at a position immediately below the liquid level 12a at the same level.
A communication hole 8a having a predetermined diameter that communicates with each other is formed to penetrate. That is, the communication hole 8a is formed at a position submerged slightly below the liquid surface 12a. The diameter of the communication hole 8a allows the flow of the liquid 12 between the sub-fluid chambers 6 and 7 when the anti-vibration mount is in a stationary state. Fluid chamber 6,7
The diameter is set so as to substantially prevent the flow of the liquid 12 therebetween. Specifically, when the passage cross-sectional area of the first orifice 9 is A1, the passage length is L1, the passage cross-section of the communication hole 8a is A0, and the passage length is L0, (A1 / L1)> (A0 / L0).

The orifices 9 and 10 are arranged such that the portions of the thin rubber layer 3a (see FIG. 3) between the main fluid chamber 5 and the sub-fluid chambers 6 and 7 have a predetermined width in the cylinder axis X direction. The outer cylindrical body 2 is cut out in the direction
And is formed between the inner peripheral surfaces of the two. Although both orifices 9 and 10 have the same passage length,
The orifice 9 has a relatively narrow width so as to generate liquid column resonance in a predetermined low frequency range, and the second orifice 10 has a relatively wide width so as to generate liquid column resonance in a predetermined high frequency range. It has been. Thus, the main fluid chamber 5 and the first fluid through the first orifice 9 respond to vibration input in a predetermined low frequency range.
Vibration is prevented by resonance of the liquid column with the sub-fluid chamber 6, while the second orifice 1
The vibration is prevented by the liquid column resonance between the main fluid chamber 5 and the second sub-fluid chamber 7 via the “0”.

In FIG. 1 and FIG. 2, reference numeral 3d denotes a rebound-side stopper integrally formed with the elastic body 3 so as to protrude toward the through space 8, and this stopper 3d is provided on the cylindrical wall of the recess 4b. By hitting the bottom wall, the elastic body 3 is restricted so as not to be displaced further upward.

Next, a method of manufacturing the liquid-filled anti-vibration mount having the above configuration will be described. First, the inner cylinder 1 and the intermediate cylinder 4 are integrally vulcanized and formed with the elastic body 3 and the partition wall 8 as described above. I do. Then, the integrally molded product and the outer cylinder 2
Are arranged so that the cylinder axis X is in the vertical direction, and the rubber thin layer 3a on the outer peripheral surface of the integrally molded product is pressed into the inner peripheral surface of the outer cylindrical body 2 from above, and the main fluid chamber is formed. The press-fitting is temporarily stopped in a state where a gap is provided between the upper end portion of the space 5 and the upper end opening edge 2a of the outer cylindrical body 2. Then, the liquid 12 is injected from the gap by a predetermined amount in consideration of the air amount of the air chambers 6b and 7b, and then the integrated molded product is press-fitted to the end. Finally, the upper and lower opening edges of the outer cylinder 2 are caulked to integrate the integrally formed product with the outer cylinder 2.

According to this manufacturing method, since it is not necessary to perform the assembling in the liquid tank filled with the liquid 12, there is no need to cause the scattering of the liquid by press-fitting or to wash the liquid attached to the outer surface after the assembling. Also, if the manufactured vibration damping mount is arranged so that the cylinder axis X is horizontal and the main fluid chamber 5 is located below and the sub fluid chambers 6 and 7 are located above, the enclosed air is elastic. 3 along the guide surface 14 and the two orifices 9, 1
0 is naturally guided to the main fluid chamber side openings 9b, 10b, and the air is passed through both orifices 9, 10 to both sub fluid chambers 6, 7
to go into. Then, the liquids 12 in the two sub-fluid chambers 6 and 7 circulate with each other, so that the liquid level 12
a is equalized, so that both sub-fluid chambers 6,
7 is an air chamber portion 6 having a predetermined set air amount (set volume).
b, 7b.

Next, the operation and effect of the first embodiment having the above configuration will be described below.

When vertical vibrations in the low frequency range are input to the elastic body 3 via the outer cylindrical body 2, the inner cylindrical body 1 is relatively displaced in the vertical direction. Due to this displacement, the main fluid chamber 5 and the sub-fluid chambers 6 pass through the first and second orifices 9, 10.
The liquid 12 flows between the liquid chambers 6a and 7a. At this time, since the second orifice 10 has a larger cross-sectional area than the first orifice 9, first, a large flow rate of the liquid 1
2 tries to flow into the liquid chamber 7a of the second sub-fluid chamber 7, but since the air chamber 7b of the second sub-fluid chamber 7 has a small volume, the air in the air chamber 7b is compressed by the inflow. As a result, the rigidity of the air chamber portion 7b increases more quickly, so that the liquid 12 in the main fluid chamber 5 hardly flows into the second orifice 10. For this reason, the liquid 12 in the main fluid chamber 5 moves to the first orifice 9 side, and the amount of the liquid 12 flowing through the first orifice 9 increases, and the liquid column resonance through the first orifice 9 causes the above-described liquid column resonance. The input vibration in the low frequency range is attenuated.

When the liquid 12 flows through the first orifice 9, the liquid level 1 of the liquid chamber 6 a of the sub-fluid chamber 6 is increased.
The liquid chamber portion 6a and the air chamber portion 6b are sealed so that the first orifice 9 is located above the auxiliary fluid chamber side opening 9a.
Is provided, the flow of the liquid 12 through the first orifice 9 is enabled by the compression / expansion of the air 13 in the air chamber portion 6b.

In addition, at the time of the vibration input, the through-hole 11 exists above the elastic body 3, so that even if the input vibration has a large amplitude, the elastic body 3 has an excessively large tensile stress. Large displacement can be made without any trouble, and the function can be fully exhibited as an engine mount. Even if the large-amplitude vibration is input and the internal pressure of each of the sub-fluid chambers 6 and 7 increases, the sub-fluid chambers 6 and 7 are recesses 4 b which are part of the intermediate cylinder 4 and are substantially rigid. Is defined by the outer wall 2 and the outer wall 2, the strength of the members (recess 4b, outer cylinder 2) defining the sub-fluid chambers 6 and 7 is reduced by an elastic film member such as a rubber thin film. As a result, the pressure can be significantly increased, and the possibility of breakage due to the internal pressure can be avoided. Therefore, in the bush type anti-vibration mount, the through space 11 can be provided without any trouble.

On the other hand, when vibrations in a high-frequency range in the vertical direction are input to the elastic body 3 through the outer cylindrical body 2, the first orifice 9 is locked in a state where the flow of the liquid 12 does not substantially occur. The volume fluctuation of the main fluid chamber 5 is compensated based on the compression of the air chamber portion 7b of the second sub-fluid chamber 7, and the second sub-fluid chamber 7
The input vibration in the high frequency range is attenuated by the liquid column resonance via the second orifice 10 that communicates with the main fluid chamber 5.

As described above, according to the first embodiment, in order to obtain the vibration damping effect of the input vibration in the two frequency ranges of the low frequency range and the high frequency range, the first and second two orifices 9, 1
0, the recess width 4b of the intermediate cylinder 4 and the outer cylinder 2 are set.
Can be achieved by a simple structure in which only the partition wall 8 partitions the space between the first and second sub-fluid chambers 6 and 7. In addition, by setting the air volume of each of the air chamber portions 6b, 7b of the two sub-fluid chambers 6, 7 to a predetermined value, it is possible to effectively prevent the input vibration in the two frequency ranges. Become like

FIG. 5 shows that the first vibration system constituted by the main fluid chamber 5 and the first sub-fluid chamber 6 via the first orifice 9 is used in a frequency range P1 of a shake vibration of a vehicle (frequency is 10 to 1).
(5 Hz region), while the second vibration system constituted by the main fluid chamber 5 and the second sub-fluid chamber 7 via the second orifice 10 generates the muffled sound of the vehicle. Frequency range P2 (frequency is 150-180H
(area z)) shows the test results when tuning is performed so that an anti-vibration effect occurs. According to this, a peak portion of the loss coefficient (tan δ) occurs in the frequency range P1, and a bottom portion of the dynamic spring constant Kd occurs in the frequency range P2.
The vibration damping effect is obtained in both frequency ranges P1 and P2, and the dynamic spring constant in the frequency range P2 is compared with the case of only one vibration system without the above-mentioned second vibration system (shown by a dashed line in the same figure). Kd is reduced. Note that the above frequency range P
Tuning for changing P1 and P2 can be easily performed by changing the passage width of the orifices 9 and 10.

The air chamber 6 of each of the sub-fluid chambers 6, 7 is provided.
The air 13 b and 7 b are mixed into the liquid 12 by receiving the vibration input, and even if the air bubbles enter the main fluid chamber 5 through the orifices 9 and 10 as the liquid 12 flows, the air bubbles remain in the main fluid chamber 5. 5 rises in the liquid 12 and hits the guide surface 14, and is guided by the guide surface 14 so that each of the orifices 9, 10
The main fluid chamber side openings 9b, 10b are guided to the respective sub-fluid chambers 6, 7 through the respective orifices 9, 10. Therefore, it is possible to reliably prevent bubbles from remaining in the liquid 12 in the main fluid chamber 5. Moreover, in the two sub-fluid chambers 6 and 7, the liquid surface 12a of the two liquid chambers 6a and 7a is automatically set by the flow of the liquid 12 between the two liquid chambers 6a and 7a through the communication hole 8a. At the same level,
It is possible to automatically maintain the air chamber portions 6b and 7b each having a predetermined set volume. As a result, the desired vibration damping performance through the orifices 9 and 10 can be maintained. Such an operation and effect is caused by a change in posture as in the case where the manufactured anti-vibration mount is turned upside down in the process of transporting or mounting the manufactured anti-vibration mount to the vehicle.
The same can be obtained when the volume fluctuations of the air chambers b and 7b occur, and when the vehicle is assembled to the vehicle, the above-mentioned volume fluctuations are automatically corrected to ensure that the volumes of the air chambers 6b and 7b are at predetermined levels. Can be something.

<Second Embodiment> FIGS. 6 to 8 show a liquid-filled anti-vibration mount according to a second embodiment of the present invention. This second embodiment has three vibration systems. In the figure, reference numeral 16 denotes a first sub-fluid chamber constituted by a liquid chamber 16a and an air chamber 16b, 17 denotes a second sub-fluid chamber constituted by a liquid chamber 17a and an air chamber 17b, and 18 denotes a liquid chamber. Part 1
8a and a third sub-fluid chamber constituted by the air chamber portion 18b,
Reference numerals 19 and 20 denote first and second partition walls, and reference numeral 21 denotes a first orifice for communicating the first auxiliary fluid chamber 16 with the main fluid chamber 5.
Reference numeral 2 denotes a second orifice connecting the second sub-fluid chamber 17 and the main fluid chamber 5, and reference numeral 23 denotes a third orifice connecting the third sub-fluid chamber 18 and the main fluid chamber 5. That is, in the second embodiment, the space between the recess 4 b of the intermediate cylinder 4 and the outer cylinder 2 is
By forming one partition wall 19, 20, three sub-fluid chambers 16, 17, 18 are formed, and three sub-fluid chambers 1 are formed.
6, 17, and 18 are communicated with the main fluid chamber 5 by individual orifices 21, 22, 23, respectively.

The remaining structure of the liquid-filled anti-vibration mount is the same as that of the first embodiment. Therefore, only the differences will be described below, and members having the same structure as the first embodiment will be described. Are denoted by the same reference numerals, and detailed description thereof will be omitted.

The first partition wall 19 is formed so as to extend in the recess 4b in the same direction as the direction of the cylinder axis X. The first partition wall 19 allows the first sub-fluid chamber 16 (left side in FIG. 7) to be formed.
The second and third two sub-fluid chambers 17 and 18 (right side in FIG. 7) are partitioned and partitioned from each other. Further, the second partition wall 20 is formed so as to extend from the first partition wall 19 to the inner peripheral surface of the outer cylinder 2 in the left-right direction orthogonal to the cylinder axis X. The second sub-fluid chamber 17 and the third sub-fluid chamber 18 are partitioned from each other. These first to third sub-fluid chambers 16 to
The first and second partition walls 19 and 20 allow the first air chamber portion 16b to have a predetermined large volume for vibration isolation in a low-frequency range according to the same policy as that of the first embodiment. Air chamber 1
7b has a predetermined medium volume for vibration isolation in the medium frequency range,
The air chamber portion 18b is formed so as to have a predetermined small volume for vibration isolation in a high frequency range.

The first sub-fluid chamber 16 and the third sub-fluid chamber 18 communicate with each other through a communication hole 19a formed in the first partition wall 19, and the first sub-fluid chamber 16 and the third sub-fluid chamber 16 communicate with each other through a communication hole 19b. The second sub-fluid chamber 17 communicates with the second sub-fluid chamber 17 and the second sub-fluid chamber 17 and the third sub-fluid chamber 18 communicate with each other through a communication hole 20 a formed in the second partition wall 20. The positions of the communication holes 19a, 19b, and 20a are the same as those in the first embodiment.
The volumes of 17b and 18b are automatically set to a predetermined set volume, and the diameter of each hole is set to a small diameter such that the flow of the liquid 12 is substantially cut off when low-frequency vibration is input. I have.

On the other hand, the first orifice 21 is set to have a narrow width so as to cause liquid column resonance by vibration input in a predetermined low frequency range (for example, a frequency range of shake vibration of a vehicle), and the second orifice 22 is set to a predetermined width. The width is set to a medium width so as to cause liquid column resonance by vibrating force in a middle frequency range (for example, a frequency range of idle vibration of the vehicle) (see FIG. 9), and the third orifice 23 has a predetermined high frequency range ( For example, the width is set to be wide so that a liquid column resonance is generated by a vibration input in a frequency range of a muffled sound of a vehicle.

In the case of the second embodiment, FIG.
As shown in the characteristic diagram of FIG.
1 (10 to 15 Hz), a first sub-fluid chamber 16 and a main fluid chamber 5 via the first orifice 21
A peak portion of the loss coefficient is generated by the vibration system, and the frequency range P2 of the idle vibration (20 in the case of an in-line four-cylinder engine).
At 25 Hz), a bottom portion of the dynamic spring constant Kd is generated by the second vibration system constituted by the second sub-fluid chamber 17 and the main fluid chamber 5 via the second orifice 22, and the frequency range of the booming sound P3 ( At 100 to 200 Hz), the bottom portion of the dynamic spring constant Kd is generated by the third vibration system constituted by the third sub-fluid chamber 18 and the main fluid chamber 5 via the third orifice 23. This makes it possible to prevent input vibration in three different frequency ranges.

In addition, even if three vibration systems are provided, this can be achieved with a simple structure. In addition, by setting the amount of air to each of the sub-fluid chambers 16 to 18, each of the vibration systems can be used as an object. Liquid column resonance can be effectively generated.

<Other Embodiments> The present invention relates to the first embodiment.
The present invention is not limited to the second embodiment, and includes various other embodiments. That is, in the first and second embodiments, the guide surface having the function of a stopper that projects the central portion 3c of the lower surface of the elastic body 3 downward as a guide surface and contacts the inner peripheral surface of the outer cylindrical body 2 during downward displacement. 14 is shown, but not limited to this, the cross-sectional shape may be V-shaped by the left and right surfaces sandwiching the lowest point. For example, the left and right surfaces sandwiching the lowest point are flat, or convex downward or upward. May be configured.

In the first embodiment, two vibrating systems are formed, and in the second embodiment, three vibrating systems are formed. However, the present invention is not limited to this, and the recess 4b of the intermediate cylindrical body 4 and the outer cylindrical body 2 may be formed. The inner peripheral surface is partitioned so that, for example, four sub-fluid chambers are formed, and each sub-fluid chamber is communicated with the main fluid chamber 5 by an independent orifice to form four vibration systems. Vibration isolation of vibrations in four frequency ranges can be achieved.

In the first and second embodiments, the recess 4b defining the sub-fluid chambers 6, 7, 16 to 18 is formed in a groove shape extending in the left-right direction. You may comprise in a shape. In this case, the partition wall 8 or the like may be formed by a convex portion when the partition wall 8 or the like is formed in a concave shape.

In the first and second embodiments, the air chambers of the second sub-fluid chamber 7 or the second and third sub-fluid chambers 17 and 18 on the side for damping the input vibration on the high frequency side are used. Is set such that the liquid levels 12a of all the sub-fluid chambers 7, 8, 16 to 18 are at the same level. However, the present invention is not limited to this. May be set. In other words, it is sufficient that the air amount in the high-frequency side sub-fluid chamber does not exceed a certain maximum value determined for securing the flow amount of the liquid 12 in the first orifices 9 and 21 at the time of low-frequency vibration input. The liquid level of each sub-fluid chamber need not always be the same. In this case, the communication holes 8a, 19
The positions of a, 19b, and 20a may be set so that the uppermost edge of each communication hole is positioned on the liquid surface determined by the maximum air amount of the sub-fluid chamber on the high frequency side.

In the first and second embodiments, the air 13 is used as the gas to be filled in each sub-fluid chamber. However, the present invention is not limited to this, and the gas is expanded and compressed through the orifices 9 and 10 and the like. Any type that allows the flow of the liquid 12 between the main fluid chamber 5 and each sub-fluid chamber may be employed. For example, nitrogen gas or the like may be used.

Further, in the first and second embodiments,
The outer cylinder 2 is connected to the engine and the inner cylinder 1 is connected to the vehicle body. However, the present invention is not limited to this.
May be connected to the vehicle body side, and the inner cylinder 1 may be connected to the engine side. In this case, the elastic body may be configured to be supported in a state in which the inner cylindrical body is eccentric relative to the outer cylindrical body upward before the connection.

[0046]

As described above, according to the liquid-filled anti-vibration mount according to the first aspect of the present invention, the main fluid chamber and the individual sub-fluids communicated with the main fluid chamber by the individual orifices. The two sub-fluid chambers can constitute two or more vibration systems. The three sub-fluid chambers provide vibration isolation effects in two different frequency ranges, and the three sub-fluid chambers provide three different vibration systems. It is possible to obtain a vibration isolation effect in a frequency range. In addition, since the amount of gas sealed in each sub-fluid chamber is specified according to the frequency range in which vibration is to be prevented, even when vibration on the low frequency side is input, the amount on the higher frequency side is increased. By restricting the flow of liquid through another set orifice, it is possible to secure the flow amount of liquid to the input low-frequency band orifice orifice sub-fluid chamber, whereby two or more different orifices are different from each other. In this frequency range, the liquid column resonance can be effectively exhibited, and the vibration of the input vibration can be effectively prevented.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the tensile stress acting on the elastic body with respect to a large-amplitude vibration input is formed by the formation of the through-hole. In addition to being able to cope with large displacements, it is possible to avoid the possibility of breakage of the partition wall between each of the sub-fluid chambers and the through-hole even if a large internal pressure is received by a large amplitude vibration input. . Further, the partition wall connecting the cylindrical wall and the outer cylindrical body, which are rigid members, can easily form two or more auxiliary fluid chambers of a predetermined volume. Even one or four auxiliary fluid chambers can be easily formed.

According to the third aspect of the invention, in addition to the effects of the first or second aspect, the amount of gas in the two or more sub-fluid chambers is reduced by the movement of the liquid through the communication hole. While it is possible to automatically correct and maintain the initially set amount, even if vibrations in the low frequency range to the high frequency range are input, the flow of the liquid through the communication hole substantially stops. Therefore, the rigidity of the gas portion sealed in each of the sub-fluid chambers can be reliably obtained, whereby the vibration of the input vibration based on the liquid column resonance of each orifice can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a cross-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 a sectional view taken along line BB of FIG. 1;

FIG. 4 is an exploded perspective view of an inner cylinder and an intermediate cylinder.

FIG. 5 is a diagram illustrating a relationship between a dynamic spring constant, a loss coefficient, and a frequency in the first embodiment.

FIG. 6 is a diagram corresponding to FIG. 2, showing a second embodiment.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a sectional view taken along line DD of FIG. 7;

FIG. 9 is a sectional view taken along line EE of FIG. 7;

FIG. 10 is a diagram illustrating a relationship between a dynamic spring constant, a loss coefficient, and a frequency according to the second embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inner cylinder 2 outer cylinder 3 elastic body 4 intermediate cylinder 5 main fluid chamber 6 first sub-fluid chamber 7 second sub-fluid chamber 8 partition wall 8a communication hole 9 first orifice 10 second orifice 9a sub-fluid chamber side Opening 10a Sub-fluid chamber side opening 11 Through space 12 Liquid 12a Liquid level 13 Air (gas) 16 First sub-fluid chamber 17 Second sub-fluid chamber 18 Third sub-fluid chamber 19 First partition wall 20 Second partition wall 19a , 19b, 20a Communication hole 21 First orifice 22 Second orifice 23 Third orifice

Claims (3)

[Claims] An inner cylinder having a cylinder axis arranged laterally; an outer cylinder surrounding the inner cylinder; an elastic body connecting the outer cylinder and the inner cylinder to each other; A main fluid chamber defined in an elastic body at a lower position of the inner cylinder, a sub-fluid chamber defined in an elastic body at an upper position of the inner cylinder, and a main fluid chamber and a sub-fluid chamber And a fluid-filled vibration isolating mount having an orifice communicating the fluid chambers with each other, wherein two or more auxiliary fluid chambers are formed independently of each other. The fluid chamber and the main fluid chamber are individually communicated via different orifices. Gas is sealed in the upper part of each of the two or more sub-fluid chambers, and each sub-fluid chamber has a sub-portion of the orifice. The liquid is sealed so that the liquid surface is located above the fluid chamber side opening, Each orifice is set to cause liquid column resonance in a different frequency range, and the set resonance frequency of the orifice in which the gas portion of each sub-fluid chamber communicates with each sub-fluid chamber is lower than that of the low-frequency side. A liquid-filled anti-vibration mount, characterized in that the high-frequency side is also set to have a smaller volume. 2. The intermediate cylindrical body according to claim 1, wherein the intermediate cylindrical body is embedded at an intermediate position between the inner cylindrical body and the outer cylindrical body and is embedded in an elastic body near the outer cylindrical body so as to surround the inner cylindrical body. A through space penetrating through the elastic body on the side of each sub-fluid chamber with respect to the inner cylinder in parallel to the cylinder axis of the inner cylinder, and a portion of the intermediate cylinder on the side of the respective sub-fluid chambers. A concave portion is formed on the inner cylindrical body side, and the through-cavity and each sub-fluid chamber are defined by a cylindrical wall constituting the concave portion. Each of the sub-fluid chambers is a space between the concave portion and the outer cylindrical body. A liquid-filled anti-vibration mount characterized by being formed so as to be partitioned from each other by a partition wall connecting the cylindrical wall of the concave portion and the outer cylindrical body so as to partition the mount. 3. The partition wall according to claim 1, wherein the partition walls separating the two or more sub-fluid chambers are arranged such that the liquid surfaces of the sub-fluid chambers formed by the partition walls are at the same level as each other. A communication hole is formed at a position where the gas in the sub-fluid chamber becomes a set amount, and a communication hole through which the liquid in each of the sub-fluid chambers can flow at a position immediately below the liquid level in the partition wall, The communication hole is set to have a diameter and a length at which the flow of the liquid is substantially stopped at the resonance frequency of the orifice that causes liquid column resonance in the lowest frequency band of the plurality of orifices. Enclosed anti-vibration mount.