JPH08145111A - Liquid-filled anti-vibration device - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the dynamic spring constant over the entire vibration frequency range and effectively suppress the vibration generated in a vibrating body such as an engine. A liquid-filled type vibration damping device LM1 includes a vehicle body side metal fitting 10 connected to a vehicle body (not shown), an engine side metal fitting 20 connected to an engine block (not shown),
The vehicle-body-side metal fitting 10 and the engine-side metal fitting 20 are connected to each other to support the engine, and a vibration damping portion 30 that damps vibration generated in the engine. The vibration damping unit 30 includes a main body rubber 31 that connects the inner frame 13 and the inner 24, a diaphragm 33 that closes an opening of the main body rubber 31, and a partition frame 32 that is arranged between the main body rubber 31 and the diaphragm 33. And a flexible partition plate 34 fixed to the inner surface of the partition frame 32. The peripheral edge of the flexible partition plate 34 is fixed to the inner wall of the lid-shaped rubber 32, and communication holes 34a having a diameter of 0.5 mm are formed in the surface of the flexible partition plate 34 at equal angular intervals on the same circumference. Individually formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device such as an engine mount that supports a vibration body such as an engine and absorbs the vibration, and more specifically, a liquid fluid is sealed inside. The present invention relates to a liquid-filled type vibration damping device.

[0002]

2. Description of the Related Art Conventionally, as a liquid-filled type vibration damping device of this type, as described in, for example, Japanese Patent Application Laid-Open No. 5-1740, the inside is divided into a main liquid chamber and a sub liquid chamber by a partition plate. It is known that a partitioned container-shaped elastic body, a throttle passage that connects both liquid chambers, and a liquid sealed in both liquid chambers are known.

According to this liquid-filled type vibration damping device, the flow resistance generated when the liquid in the main liquid chamber passes through the throttle passage or when the liquid in the auxiliary liquid chamber passes through the throttle passage, It is possible to effectively damp the vibration caused by the engine shake.

In addition to this, in order to damp vibrations other than engine shake, a liquid filled type vibration damping device LM2 as shown in FIG. 5 has been proposed. This liquid-filled type vibration damping device LM2 connects an internal metal fitting 51 connected to an engine block (not shown) via a bracket 50, an external metal fitting 52 connected to the vehicle body side, and both metal fittings 51, 52. Semi-container body rubber 5 with one side open
Equipped with 3. Further, the opening of the main body rubber 53 is closed by the diaphragm 54, and the space defined by the main body rubber 53 and the diaphragm 54 is the diaphragm 5.
A partition plate 55 provided inside the partition 4 divides the liquid into a main liquid chamber 56 and a sub liquid chamber 57. Further, the main liquid chamber 56 and the sub liquid chamber 57 are communicated with each other by the orifice 58, and the internal fitting 5
A bulky plate 59 is disposed at the upper end of the plate 1.

According to this liquid-filled type vibration damping device LM2,
Due to the flow resistance when the liquid L passes through the orifice 58, 10 Hz to 20 H caused by the engine shake is generated.
Vibrations having a vibration frequency of z are damped. Further, by providing the umbrella-shaped plate 59, liquid resonance occurs, and it is possible to reduce the dynamic spring constant in the vibration frequency region around 400 Hz caused by engine noise.

The partition plate 55 compensates for the increase in the dynamic spring constant due to the provision of the orifice 58, so that
The characteristic is set so as to reduce the dynamic spring constant in the vibration frequency region up to about 00 Hz.

As described above, in order to realize the target characteristics, the above-mentioned constituent elements are set, and the shape of the main body rubber 53,
By tuning the composition and the like, for example, the characteristics shown in FIG. 6 can be obtained. FIG. 6 is a graph showing the relationship between the vibration frequency and the dynamic spring constant, where the vertical axis represents the dynamic spring constant and the horizontal axis represents the vibration frequency. Also,
The solid line indicates the liquid-filled type vibration damping device LM2 having the above configuration,
The broken line shows the liquid-filled type vibration damping device which does not include the bulky plate 59.

In the liquid-filled type vibration damping device which is not provided with the umbrella-shaped plate 59, the peak of the dynamic spring constant appears in the vibration frequency region of 300 Hz to 400 Hz, which deteriorates the vibration damping performance in such region.

On the other hand, in the liquid-filled type vibration damping device LM2 having the umbrella-shaped plate 59, 300 Hz to 400 Hz is used.
The peak of the dynamic spring constant in the vibration frequency region of is eliminated. Therefore, by providing the umbrella-shaped plate 59, it is possible to suppress the vibration caused by the engine noise.

[0010]

However, the components other than the main body rubber 53 such as the orifice 58 and the bulky plate 59 in the conventional liquid-filled type vibration damping device LM2 have a damping effect and a dynamic effect in the intended predetermined vibration frequency range. This is to reduce the spring constant, and there is a problem that the dynamic spring constant cannot be reduced over the entire vibration frequency range.

That is, when the dynamic plate spring 59 is used to reduce the dynamic spring constant in the vicinity of 400 Hz, the dynamic spring constant in the vicinity of 400 Hz is reduced as shown in FIG. There was a problem that the dynamic spring constant in 1 increases due to anti-resonance.

Moreover, as shown in FIG. 7, there is a problem in tuning the rigidity of the partition plate 55. FIG. 7 is a graph showing the relationship between the vibration frequency and the dynamic spring constant, where the vertical axis represents the dynamic spring constant and the horizontal axis represents the vibration frequency. Further, the solid line shows the dynamic spring characteristics of the liquid-filled type vibration damping device provided with the high-rigidity partition plate, and the broken line shows the dynamic spring characteristic of the liquid-filled type vibration damping device provided with the low-rigidity partition plate.

As can be seen from the figure, if the rigidity of the partition plate 55 is increased, the dynamic spring constant in the low vibration frequency region increases and the dynamic spring constant in the high vibration frequency region decreases. On the other hand, if the rigidity of the partition plate 55 is lowered, the dynamic spring constant in the low vibration frequency region increases and the dynamic spring constant in the high vibration frequency region decreases.

On the other hand, if the rigidity of the main body rubber 53 is reduced, the dynamic spring constant can be expected to be reduced over the entire vibration frequency range, but the dynamic spring constant cannot be significantly reduced in consideration of its durability. There was a problem.

As described above, in the liquid-filled type vibration damping device LM2 according to the conventional example, the unevenness of the dynamic spring constant is large, the dynamic spring constant cannot be reduced over the entire vibration frequency region, and the vibration of the engine or the like cannot be achieved. There is a problem that the vibration generated from the body cannot be effectively suppressed.

The present invention has been made in order to solve the above-mentioned conventional problems, and aims to reduce the dynamic spring constant over the entire vibration frequency range, thereby effectively suppressing the vibration generated in the vibrating body such as the engine. The purpose is to do.

[0017]

To achieve the above object, a liquid filled type vibration damping device according to the present invention comprises a first metal fitting connected to a vibrating body such as an engine and a second metal fitting connected to a vehicle body. A semi-container-shaped first elastic body having one side opened while connecting the first metal fitting and the second metal fitting to each other;
A second elastic body connected to the opening edge of the elastic body and closing the opening of the first elastic body; and a liquid sealed in a space hermetically formed by the first elastic body and the second elastic body. , The space is divided into a main liquid chamber having the first elastic body as a chamber wall and a sub liquid chamber having the second elastic body as a chamber wall, and the main liquid chamber and the sub liquid chamber are communicated with each other. A flexible partition plate having a communication hole, and a throttle communication passage that connects the main liquid chamber and the sub liquid chamber.

[0018]

In the liquid-filled type vibration damping device according to the present invention having the above structure, when vibration is transmitted from the vibrating body such as the engine to the first fitting, the first elastic body is deformed and the first liquid chamber volume is changed. , And the volume of the second liquid chamber changes. Then, when the volume of the first liquid chamber decreases, the liquid in the first liquid chamber moves to the second liquid chamber via the throttle communication passage, and when the volume of the second liquid chamber decreases,
The liquid in the second liquid chamber moves to the first liquid chamber. Vibration is damped by the flow resistance generated when the liquid passes through the throttle communication passage.

Further, the liquid moves between both liquid chambers not only through the throttle communication passage but also through the communication hole formed in the flexible partition plate. Then, the vibration is damped by the flow resistance generated when the liquid passes through the communication hole.

As a result, the vibration generated in the vibrating body such as the engine is suppressed in the liquid-filled type vibration damping device, and it is difficult to transmit the vibration to the vehicle body side through the second metal fitting. Here, since the flexible partition plate has a property of being deformed by the action of an external force, the flexible partition plate is bent due to the deformation of the first elastic body due to the transmission of vibration and the change in the volume of both liquid chambers. Occurs. And, since this deflection becomes large when the vibration frequency is low, the hole area of the communication hole of the flexible partition plate also becomes large, and the flow rate of the liquid flowing in and out of both liquid chambers through the communication hole also becomes large. . As a result, the rigidity is reduced as compared with a flexible partition plate having the same rigidity.

On the other hand, when the vibration frequency is high, the deflection becomes small, so that the hole area of the communication hole of the flexible partition plate hardly changes, and the liquid passing between the two liquid chambers passes through the communication hole. The flow rate also decreases. As a result, the same rigidity as that of the flexible partition plate having the same rigidity without the communication hole can be obtained.

As described above, the rigidity of the flexible partition plate decreases in the low vibration frequency region, and the rigidity that the flexible partition plate originally has in the high vibration frequency region is exhibited.
The reduction of the dynamic spring constant will be realized in the entire vibration frequency range.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a liquid filled type vibration damping device will be described below with reference to the drawings.

First, the structure of the liquid-filled type vibration damping device LM1 according to this embodiment will be described with reference to FIGS. The liquid filled type vibration damping device LM1 is a vehicle body (not shown).
The vehicle body side metal fitting 10 connected to the engine block, the engine side metal fitting 20 connected to the engine block (not shown), the vehicle body side metal fitting 10 and the engine side metal fitting 20 are connected to support the engine, and the engine side metal occurs. A vibration damping unit 30 for damping vibration is provided.

The vehicle body side metal fitting 10 includes a vehicle body side bracket 11 directly connected to the vehicle body, a body case 12 fixed to the vehicle body side bracket 11, and an inner frame 13 engaged with the body case 12. .

The vehicle body side bracket 11 is formed in a substantially channel shape when viewed from the front, and an attachment portion 11a for connecting to the vehicle body via a bolt 25 is formed at an open end thereof. In addition, an opening 11b is formed in the ceiling portion for avoiding interference with the vehicle body side bracket 11 when an inner (described later) swings.

The main body case 12 is a bottomed cylindrical metal case, and has an opening 12a formed on the bottom surface for avoiding interference with the inner when the inner swings. Further, a flange-shaped engaged portion 12b with which the engaging portion of the inner frame 13 is engaged is formed at the upper opening edge portion. The inner frame 13 is a tubular metal frame narrowed near the bottom surface, and has an upper opening edge portion with a U-shaped cross section that engages with the engaged portion 12b of the main body case 12. A joining portion 13a is formed.

The vehicle body side bracket 11 is connected to the vehicle body via the mounting portion 11a, and the body case 12 is joined to the ceiling portion of the vehicle body side bracket 11 at the bottom surface. Further, the inner frame 13 is engaged with the engaged portion 12b of the main body case 12 via the engaging portion 13a, and is disposed so as to be substantially in close contact with the inner peripheral wall of the main body case 12.

Next, the engine side metal fitting 20 is provided with an engine side bracket 21 connected to an engine block side bracket (not shown) and an inner 24 to which the engine side bracket 21 is connected via bolts 25. .

The engine side bracket 21 has a mounting portion 21a directly connected to the engine block side bracket,
Bracket guard 22 for preventing direct contact with the vehicle body side bracket 11 when the inner 24 swings
The stopper rubber 23 is attached to the bracket guard 22. The inner 24 is a substantially cylindrical metal member whose diameter increases from the lower part to the upper part, and the bottom surface thereof has a bolt hole 24 a corresponding to the bolt 25.
Are formed.

The vibration damping portion 30 includes a main body rubber 31 connecting the inner frame 13 and the inner 24, and a main body rubber 31.
33 for closing the opening of the partition frame 3 and the partition frame 3 arranged between the main body rubber 31 and the diaphragm 33.
2 and a flexible partition plate 34 fixedly supported on the inner surface of the partition frame 32.

The main body rubber 31 is a semi-container vibration isolator having an open top and a thick bottom portion. The thick bottom portion has an inner mounting hole 31a corresponding to the shape of the inner 24. Are formed. In addition, a flange-shaped joined portion 31b that receives the joined portion 32a of the partition frame 32 is formed at the opening edge portion.

The partition frame 32 is a cylindrical rubber member whose diameter increases from the upper part to the lower part, and the upper opening is closed by the diaphragm 33. A flange-shaped engaging portion 32a corresponding to the joined portion 31b of the main rubber 31 is formed at the lower opening edge portion.

The diaphragm 33 is made of a synthetic resin material, and a fixing metal fitting 33a for fixing the diaphragm 33 to the inner frame 13 and the partition frame 32 is integrally formed on the peripheral portion of the diaphragm 33. By fixing the diaphragm 33 to the inner frame 13, the opening of the main body rubber 31 is closed.

The flexible partition plate 34 has a peripheral edge fixed to the inner wall of the partition frame 32 and has a thickness of 2.5 m.
m is a disc-shaped partition plate having a rubber hardness of 60 degrees, and as shown in FIG. 2, a communication hole 34 having a diameter of 0.5 mm is formed in the surface thereof.
Six a are formed. And each communication hole 34a is
The flexible partition plates 34 are formed at equal angular intervals on the same circumference in order to uniformize the deformation when stress is applied. The diameter of the communication hole 34a may be 0.5 mm or less.

Under the above structure, the inner frame 13 is vulcanized and adhered to the outside of the side peripheral surface of the main body rubber 31, and the inner 24 is vulcanized and adhered to the inner mounting hole 31a of the main body rubber 31. . Therefore, the inner 24 (engine-side fitting 20) is swingably supported with respect to the inner frame 13 (vehicle-side fitting 10) via the main body rubber 31.

By joining the joined portion 31b of the main body rubber 31 and the joining portion 32a of the partition frame 32, a liquid L such as ethylene glycol is provided between the main body rubber 31 and the flexible partition plate 34. A main liquid chamber 40 for sealing the liquid is formed. A sub liquid chamber 41 for sealing the liquid L such as ethylene glycol is formed between the partition frame 32 and the flexible partition plate 34.

Further, the diaphragm 33 is a fixing metal fitting 33.
a is fixed to the inner frame 13 by being caulked together with the joined portion 31b of the main rubber 31 and the joining portion 32a of the partition frame 32 at the engaging portion 13a of the inner frame 13. As a result, the diaphragm 33 closes the opening of the main body rubber 31 with the partition frame 32 interposed.

Further, the outer side surface of the partition frame 32 and the fixing fitting 33a form an orifice 43 which connects the main liquid chamber 40 and the sub liquid chamber 41. The orifice 43 is connected to the main liquid chamber 40 through an opening (not shown) formed in the partition frame 32, and is connected to the sub liquid chamber 41 through an opening (not shown) also formed in the partition frame 32.

The upper portion of the main body case 12 from the engaged portion 12b is covered with a cover 35 made of a rubber material in order to prevent dust from adhering to the diaphragm 33 and dust from entering a crimped portion. There is. And diaphragm 3
The space surrounded by 3 and the cover 35 is an air chamber, and this air chamber communicates with the atmosphere via an air vent hole (not shown) formed in the cover 35.

Next, the operation of the liquid-filled type vibration damping device LM1 according to this embodiment having the above structure will be described. Vibration generated in the engine, which is a vibrating body, is transmitted to the inner 24 via the engine side bracket 21. Since the inner rubber 24 is swingably supported by the body rubber 31, it swings with the transmitted vibration and deforms the body rubber 31 to change the volume of the main liquid chamber 40.

As the volume of the main liquid chamber 40 decreases in this way, the liquid L in the main liquid chamber 40 moves to the sub liquid chamber 41 through the orifice 43, and when the liquid L passes through the orifice 43. 10Hz ~ 20 due to flow resistance
The vibration having the vibration frequency of Hz is absorbed, and the transmission of the vibration to the vehicle body is suppressed.

Further, since the vibration of the engine is generated intermittently, the volume of the main liquid chamber 40 also changes intermittently accordingly. As a result, the liquid L sealed in the main liquid chamber 40 is swung in accordance with the change in volume of the main liquid chamber 40, and the liquid L vibrates.

However, the flexible partition plate 34 has six
The individual communicating holes 34a are formed at equal angular intervals on the same circumference, and when the transmitted vibration frequency is low, the passing through the communicating holes 34a also allows the main liquid chamber 40 to the sub liquid chamber 41 to pass. The liquid L moves to. Therefore, the low-vibration vibration component of the vibration generated in the liquid L is absorbed by the low-flexibility flexible partition plate 34.

That is, when the vibration frequency is low, the flexible partition plate 34 is largely displaced, so that the communication hole 34a is largely deformed and the area of the communication hole 34a is increased. As a result, the passage amount of the liquid L moving from the main liquid chamber 40 toward the sub liquid chamber 41 via the communication hole 34a increases,
A dynamic spring constant similar to that when a partition plate with low rigidity is used can be obtained.

On the other hand, when the vibration frequency is high, the flexible partition plate 34 is hardly displaced, so that the communication hole 34a is not deformed and the area of the communication hole 34a does not change. As a result, the liquid L passes through the communication hole 34a and the main liquid chamber 4
It hardly moves from 0 to the sub liquid chamber 41, and a dynamic spring constant similar to that in the case of using a partition plate having no communication hole 34a can be obtained.

Here, the reason for this will be described with reference to FIG. FIG. 3 is a graph showing the relationship between the passage area and the displacement due to the difference in the number of communication holes 34a formed in the flexible partition plate 34, the vertical axis indicates the passage area, and the horizontal axis indicates the flexibility. The vertical displacement of the sex partition plate 34 is shown. The solid line shows the relationship when the number of communication holes 34a is small, and the broken line shows the relationship when the number of communication holes 34a is large.

In the region where the displacement is small, that is, the region where the vibration frequency is high, the passage area is almost 0 mm ² regardless of the number of the communication holes 34a. Therefore, the partition plate has the same degree of rigidity as the partition plate having no communication hole 34a, and exhibits the same behavior as the high-rigidity partition plate shown in FIG.

On the other hand, in the region where the displacement is large, that is, in the region where the vibration frequency is low, the passage area varies depending on the number of the communication holes 34a, but the passage area is common. When the passage area increases in this way, the amount of liquid L passing through the flexible partition plate 34 increases. As a result, it becomes difficult for the flexible partition plate 34 to suppress the fluctuation of the liquid L, and the flexible partition plate 34 functions as a low-rigidity partition plate.
It behaves similarly to the low-rigidity partition plate shown in.

As described above, the communication hole 3 is formed in the flexible partition plate 34.
By forming 4a, in the low vibration frequency region, a low dynamic spring constant as high as that of a partition plate having low rigidity is exhibited, and in the high vibration frequency region, as a high rigidity partition plate originally possessed by the flexible partition plate 34. Shows a low dynamic spring constant.

Further, as can be seen from the graph, the passage area sharply increases in a smaller displacement region when the number of communicating holes 34a is large, and the displacement is larger when the number of communicating holes 34a is small. It is gradually increasing in the area. Therefore, some of the communication holes 34a serve as tuning elements, and the number of the communication holes 34a exhibiting a desired dynamic spring characteristic may be set.

Next, the dynamic spring characteristics of the liquid filled type vibration damping device LM1 according to this embodiment will be described with reference to FIG.
FIG. 4 shows the liquid-filled type vibration damping device LM according to this embodiment.
3 is a graph showing the characteristics in No. 1, in which the vertical axis represents the dynamic spring constant and the horizontal axis represents the vibration frequency. Further, the solid line shows the characteristic when the flexible partition plate 34 having the communication hole 34a and high rigidity is provided, and the broken line shows the characteristic when the highly rigid partition plate without the communication hole 34a is provided. Shows the characteristics when a low-rigidity partition plate having no communication hole 34a is provided.

As can be seen from the graph, the flexible partition plate 3
In the low vibration frequency range, the liquid-filled type vibration damping device LM1 provided with No. 4 behaves similarly to the vibration damping device including the low-rigidity partition plate exhibiting a low dynamic spring constant in the low vibration frequency region. On the other hand, in the high vibration frequency region, the same behavior as that of the vibration isolation device provided with the high-rigidity partition plate that exhibits a low dynamic spring constant up to a higher vibration frequency region than the low-rigidity partition plate is exhibited.

Further, the peak around 300 Hz, which was remarkable in the high-rigidity partition plate having no communication hole 34a, disappeared, and the same damping effect as when the bulky plate was provided was obtained. Further, as can be seen by comparing with FIG. 6, an increase in the dynamic spring constant due to anti-resonance in a region near 200 Hz or in a region over 400 Hz, which was a problem when damping the vibration by the bulky plate, appears. However, a smoother dynamic spring characteristic is obtained.

As described above in detail with reference to the embodiments, the liquid filled type vibration damping device LM1 according to the present embodiment includes the highly rigid flexible partition plate 34 having the communication hole 34a formed therein. . Therefore, in the low vibration frequency region, since the flexible partition plate 34 is largely displaced and the hole area of the communication hole 34a is increased, the amount of the liquid L passing from the main liquid chamber 40 to the sub liquid chamber 41 is increased. It exhibits characteristics as a partition plate with low rigidity, and the dynamic spring constant is reduced.

On the other hand, in the high vibration frequency range, the flexible partition plate 34 is hardly displaced and the hole area of the communication hole 34a does not change, so that the liquid L does not easily pass from the main liquid chamber 40 to the sub liquid chamber 41. Therefore, the flexible partition plate 34 functions as a partition plate having high rigidity originally possessed, and the dynamic spring constant in the high vibration frequency region is reduced.

As a result, unlike the conventional liquid-filled type vibration damping device which can realize only the reduction of the dynamic spring constant in a specific vibration frequency region, the total vibration is generated regardless of the low vibration frequency region and the high vibration frequency region. It is possible to reduce the dynamic spring constant over the frequency range.

Further, without providing a bulky plate,
The dynamic spring constant in the vibration frequency range of 300 Hz to 400 Hz can be reduced. Therefore, unlike the case where the umbrella-shaped plate is provided, the dynamic spring constant does not increase due to anti-resonance, and the product cost can be reduced.

Further, not the communication passage like the orifice 43, but the communication hole 34a formed in the thin disk-shaped partition plate.
As a result, the movement of the liquid between the main liquid chamber 40 and the sub liquid chamber 41 is realized, so that it is not necessary to consider the influence on the damping coefficient.

The present invention can be variously modified and improved without departing from the spirit thereof. For example, although the present embodiment has been described using the flexible partition plate 34 having the six communication holes 34a formed on the same circumference at equal angular intervals,
The number of communication holes 34a is a tuning element, and may be a number that can obtain a desired dynamic spring characteristic.

Although the diameter of the communication hole 34a is set to 0.5 mm, it may be any size as long as it regulates the movement of the liquid between the main liquid chamber 40 and the sub liquid chamber 41 in the high vibration frequency range.
If it is 0.5 mm or less, the movement of the liquid can be regulated. Furthermore, the thickness of the flexible partition plate 34 is 2.5.
It is not limited to mm, and may be determined depending on the hardness of the material used.

Further, although a rubber disk material having a rubber hardness of 60 degrees is used as the flexible partition plate 34, the rubber hardness may be such that a desired dynamic spring constant is realized according to the conditions. Further, instead of the rubber disc material, a material such as synthetic resin may be used.

The technical ideas other than the claims that can be understood from the above embodiments will be described below along with their effects. (1) In the liquid filled type vibration damping device according to claim 1,
The liquid-sealed vibration isolator, wherein the flexible partition plate has one or more communication holes.

If at least one communication hole is formed in the flexible partition plate, the movement of the liquid between the main liquid chamber and the sub liquid chamber can be permitted. The amount of liquid passing through the plate can be defined. That is, the degree of reduction in rigidity of the flexible partition plate can be adjusted by the number of communication holes.

(2) In the liquid-filled type vibration damping device according to claim 1 or (1), the communication hole provided in the flexible partition plate has a diameter of 0.5 mm or less. Liquid-filled anti-vibration device.

With such a structure, the rigidity of the flexible partition plate in the high vibration frequency region can be maintained at the same level of rigidity as the flexible partition plate having no communication hole. That is, if the diameter of the communication hole is too large, the movement of the liquid between the main liquid chamber and the sub liquid chamber is always permitted, and the dynamic spring constant in the entire vibration frequency region is reduced by one flexible partition plate. This is because it cannot be realized.

[0067]

As described above, the liquid filled type vibration damping device according to the present invention can reduce the dynamic spring constant over the entire vibration frequency range. Further, the vibration generated in the vibrating body such as the engine can be effectively suppressed.

[Brief description of drawings]

FIG. 1 is a front sectional view of a liquid filled type vibration damping device.

FIG. 2 is a perspective view showing the overall configuration of a flexible partition plate.

FIG. 3 is a graph showing the relationship between passage area and displacement in a flexible partition plate.

FIG. 4 is a graph showing the characteristics of the liquid-filled type vibration damping device.

FIG. 5 is a front sectional view of a liquid filled type vibration damping device according to a conventional example.

FIG. 6 is a graph showing the characteristics of the liquid-filled type vibration damping device with and without the umbrella-shaped plate.

FIG. 7 is a graph showing the characteristics of the liquid-filled type vibration damping device depending on the rigidity of the partition plate.

[Explanation of symbols]

10 ... Main body side metal fitting, 11 ... Car body side bracket, 12 ... Main body case, 13 ... Inner frame, 20 ... Engine side metal fitting, 21 ... Engine side bracket, 24 ... Inner, 3
0 ... Vibration damping part, 31 ... Main body rubber, 32 ... Partition frame, 33 ... Diaphragm, 34 ... Flexible partition plate, 40 ...
Main liquid chamber, 41 ... Sub liquid chamber, 43 ... Orifice, LM1 ... Liquid filled type vibration damping device

Claims (1)

[Claims] 1. A first metal fitting connected to a vibrating body such as an engine, a second metal fitting connected to a vehicle body, a first metal fitting and a second metal fitting, and a half opening on one side. A container-shaped first elastic body, a second elastic body connected to an opening edge portion of the first elastic body and closing the opening of the first elastic body, the first elastic body and the second elastic body And a liquid enclosed in a space hermetically formed by, the space is divided into a main liquid chamber having the first elastic body as a chamber wall, and a sub liquid chamber having the second elastic body as a chamber wall,
A liquid including a flexible partition plate having a communication hole that communicates the main liquid chamber and the sub liquid chamber, and a throttle communication passage that communicates the main liquid chamber and the sub liquid chamber. Enclosed anti-vibration device.