JPH094675A - Liquid enclosing type vibration preventer - Google Patents

Abstract

PURPOSE: To display a dilatant effect on vibrations of extremely low frequency and high amplitude. CONSTITUTION: An insulator 5 is provided between a connective fitting 6 connected to the vibration body side and a holder 9 connected to the car body side member or the like. A main chamber 2 and sub-chamber 3 in which dilatant fluid is enclosed are provided in the lower part of the insulator 5. An orifice 1 through which the dilatant fluid flows is provided between these main chamber 2 and sub-chamber 3. In a part of the orifice 1 is provided a resistance part consisting of a collision chamber 11 for largely converting the flow direction of the fluid flowing into the orifice 1 and a plurality of through holes 15 or the like provided on the side wall of the collision chamber. Thus, the dilatant fluid receives large resistance to about 5Hz of vibration input at the resistance part consisting of the collision chamber 11 or the like to be solified by pressure based on the resistance. Hence, the spring constant is heightened and the vibration is restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled type vibration-damping device capable of obtaining a vibration-damping effect based on the flow of a liquid (fluid) sealed inside. The liquid to be enclosed is made of a so-called dilatant fluid that is a low-frequency vibration and causes a solidification phenomenon of the liquid (fluid) under high-amplitude vibration. The present invention relates to a liquid-filled type vibration damping device for suppressing the above.

[0002]

2. Description of the Related Art Among vibration damping devices, particularly engine mounts for automobiles, the engine, which is a power source, is used under various conditions from idling to the maximum rotation speed. Therefore, it must be able to handle a wide range of frequencies. In general, a vibration damping device as an engine mount is intended to block idling vibrations that target torque fluctuations caused by explosive combustion of an engine or shakes that target resonance phenomena between an engine and an engine mount. The system settings (tuning) have been made. However, in order to prevent (isolate) these vibrations, it is difficult to avoid the resonance phenomenon by selecting the spring constant, and it is difficult to avoid the resonance phenomenon. In some cases, the transmission of vibration to the side may be cut off. In order to meet these plural conditions, a liquid-filled type vibration damping device in which two liquid chambers are provided inside and an orifice between them is connected has been devised and is known.

By the way, the conventional liquid-filled type vibration damping device has, for example, as shown in FIG. 11, a coupling fitting 60 mounted on the side of a vibrating body such as an engine, and a cup-shaped holder 90 mounted on a body member or the like. An insulator 50 which is provided between the connecting metal fitting 60 and the holder 90 and is made of a vibration-proof rubber or the like, and a main portion which is provided below the insulator 50 and in which an incompressible fluid (liquid) is enclosed. A chamber 20, a sub chamber 30, an orifice 10 which connects the main chamber 20 and the sub chamber 30 and has an annular shape, and an air chamber 70 into which a compressive fluid such as air is introduced. It is basically composed of a diaphragm 40 for partitioning the air chamber 70 and the sub chamber 30. For the vibration of a predetermined frequency, for example, engine shake, a high damping characteristic is obtained by the action of the orifice 10, and for the engine idling vibration, the insulator 5 is used.
A low dynamic spring constant is obtained by the action of 0 or the like. In this way, for vibration of a specific frequency,
A low dynamic spring characteristic or a high damping characteristic is formed so as to cut off the engine idling vibration or the engine shake.

[0004]

The above-mentioned conventional device having such a structure is intended to cut off vibrations at frequencies near 10 Hz to 30 Hz, such as engine idling vibration and engine shake. However, in recent automobiles, extremely low frequency engine vibrations of about 5 Hz, which is a lower frequency vibration than the above engine idling vibration or engine shake, has been a problem. In order to suppress the engine vibration at an extremely low frequency of around 5 Hz, a dilatant fluid is used as the enclosed liquid, which has been already known, for example, from Japanese Patent Publication No. 2-55659. However, such dilatant fluids are
Even if it is used as it is for a liquid-filled type vibration damping device having a conventional structure as shown in FIG. 11, it is difficult to damp the engine vibration at an extremely low frequency of about 5 Hz. That is, even if the dilatant fluid in the main chamber 20 flows into the orifice 10 while vibrating at an extremely low frequency of about 5 Hz, it does not undergo sufficient compression there and the fluid (liquid ) Solidification phenomenon does not occur. As a result, a sufficient dilatant effect cannot be obtained, and the vibration of the extremely low frequency of about 5 Hz cannot be suppressed. In order to solve such a problem, it is intended to provide a liquid-filled type vibration damping device having a dilatant fluid, which is capable of exhibiting sufficient vibration damping capability against vibrations at extremely low frequencies around 5 Hz. That is the object (problem) of the present invention.

[0005]

In order to solve the above-mentioned problems, the following measures are taken in the present invention. That is, a connecting fitting attached to the vibrating body side, a holder attached to a member on the vehicle body side, an insulator between the connecting fitting and the holder that exerts a function of blocking vibrations from the vibrating body, and the insulator. A main chamber and a sub-chamber, which are provided in series with each other and in which an incompressible fluid is enclosed, an orifice for flowing the incompressible fluid between the main chamber and the sub-chamber, and a compressibility such as air. Regarding a liquid filled type vibration damping device comprising an air chamber into which a fluid is introduced and a diaphragm partitioning the air chamber from the sub chamber, a dilatant is applied to a non-compressible fluid filled in the main chamber and the sub chamber. While being made of a fluid, at least a part of the orifice, when the dilatant fluid flows in the orifice,
A configuration is adopted in which a resistance portion is provided so as to generate resistance in the flow of the fluid.

Further, in the liquid-filled type vibration damping device having the dilatant fluid, the resistance portion is provided on at least one of the main chamber side outlet portion and the sub chamber side outlet portion of the orifice. There is a collision chamber consisting of a space portion in which the flow direction of the dilatant fluid is largely changed, and is provided on the side wall of the collision chamber, and the opening area of each is a small value, and the sum is A plurality of through holes formed so as to have a value equal to or larger than the value of the cross-sectional area of the general opening cross-section of the orifice is adopted.

Further, in the liquid-filled type vibration damping device having the dilatant fluid, the resistance portion is provided on a partition plate which divides the main chamber and the sub chamber from each other. And a collision chamber formed by a space portion connected to and a screen installed in the space portion, and a wall portion of the collision chamber, the opening area of each of which is a small value, A configuration in which a plurality of through holes are formed so that the total sum is equal to or larger than the value of the cross-sectional area of the general opening cross-section of the predetermined orifice in the liquid-filled type vibration damping device Decided to take.

Further, in the liquid-filled type vibration damping device having the dilatant fluid, the resistance portion is provided in an orifice so that a turbulent flow is generated in the flow of the dilatant fluid flowing in the orifice. It was decided to adopt a configuration in which it is composed of a mesh-shaped screen formed in 1.

Further, in the liquid-filled type vibration damping device having the dilatant fluid, the resistance section has a small opening cross-sectional area, and the sum thereof is a predetermined amount forming a liquid-filled type vibration damping device. It has been decided to employ a configuration in which a plurality of pores are formed so as to have a value equal to or greater than the value of the cross-sectional area of the general opening cross-section of the orifice.

[0010]

By adopting the above construction, the following effects are exhibited in the present invention. That is, when the liquid-filled type vibration damping device according to the present invention is attached to a vibrating body such as an engine, the vibration from the vibrating body side is propagated to the insulator made of a rubber-like elastic body through the connecting fitting. come. By the way, of these vibrations
Most of the vibration including engine idling vibration is absorbed and cut off at the insulator. Therefore, most vibrations including these engine idling vibrations are blocked at the vibration isolator and are not propagated to the vehicle body side. It should be noted that vibration of a lower frequency than the engine idling vibration (about 10H
With regard to the engine shake of z), in the present invention, the liquid (fluid) flowing in the orifice is prevented from exhibiting dilatancy, and thereby exhibiting a predetermined damping characteristic. That is, as with the conventional liquid-filled type vibration damping device, the engine shake is made to exhibit high damping characteristics, thereby suppressing the vibration.

Next, these engine idling vibrations,
Alternatively, for extremely low frequency vibrations around 5 Hz, which is one step lower than the engine shake,
The vibration isolator has a high spring constant (spring characteristic) to physically suppress the vibration at the extremely low frequency. That is, in the present invention, when the fluid enclosed in the main chamber and the sub chamber is subjected to low-frequency vibration and high-amplitude vibration, the fluid is solidified from the liquid state. It is made of a so-called dilatant fluid, which has a high viscosity, and the dilatant fluid is caused to flow in the orifice to obtain the above 5 Hz.
A high spring constant (high spring characteristic) is formed with respect to front and rear extremely low frequency vibrations. This suppresses the vibration caused by the whirling phenomenon of the engine, which occurs when the engine is cranked or when the vehicle is suddenly started or suddenly accelerated. Particularly, in the invention according to claim 1, when the dilatant fluid flows in a part of the orifice in the orifice while vibrating at an extremely low frequency of about 5 Hz, the flow is suddenly increased. Since the resistance portion is provided so as to generate resistance, the action of the resistance portion compresses the dilatant fluid, thereby causing a solidification phenomenon of the fluid (liquid). As a result, the spring constant (spring characteristic) of the entire anti-vibration device becomes high, which suppresses engine vibration around 5 Hz.

According to the second aspect of the invention, the flow of the fluid flowing in the orifice is located at at least one of the main chamber side outlet and the sub chamber side outlet of the orifice. However, since a collision chamber that can be converted by approximately 90 ° is provided and a plurality of through holes each having a small opening area are provided in a part of the side wall of the collision chamber, the above orifice is used. 5Hz in
The dilatant fluid that has flowed in a vibration state of extremely low frequency before and after is subjected to a great resistance to the flow at the collision chamber. Due to this resistance, the flow becomes turbulent and receives internal pressure. As a result, the dilatant fluid is solidified, and the spring constant (spring characteristic) of the entire vibration damping device is increased. Due to the action of this high spring characteristic, the engine vibration around 5 Hz is suppressed. In addition, in the present invention, the sum of the respective opening areas of the plurality of through holes having the small opening area is set to be equal to or larger than the value of the general opening cross-sectional area of the orifice. So 10
A predetermined damping characteristic can be obtained with respect to the vibration of the engine shake of around Hz. Therefore, in the present invention, the same damping effect as in the case of the conventional liquid-filled type vibration damping device is ensured, and further,
The vibration suppressing action of the extremely low frequency around 5 Hz is performed.

Next, in the invention according to claim 3, a plurality of through holes each having a small opening area and a space portion are provided in a part of the orifice, and a mesh-shaped screen is installed inside. Since the dilatant fluid having an extremely low frequency vibration of about 5 Hz flows into the collision chamber or the like, the dilatant fluid is generated there. Will be greatly resisted by the flow. Then, due to the resistance of the flow in the collision chamber, the fluid (liquid) is subjected to pressure and exhibits a solidification phenomenon. As a result, the spring constant (spring characteristic) of the entire anti-vibration device becomes high, which suppresses the engine vibration around 5 Hz. For vibrations other than this, especially for vibrations around 10 Hz related to engine shake, the value obtained by summing the total opening areas of the plurality of through holes is equal to or greater than the value of the general opening cross-sectional area of the predetermined orifice. Since it is set to have a value of, a predetermined high attenuation characteristic can be obtained.

Further, in the invention according to the fourth aspect, since the resistance portion composed of the mesh-shaped screen or the like is provided in the orifice, the flow is carried in a state of vibration at an extremely low frequency of about 5 Hz. The flow of the resulting dilatant fluid is interrupted at the resistance portion and receives the internal pressure. As a result, the dilatant fluid is solidified, which increases the spring constant (spring characteristic) of the entire vibration damping device having the dilatant fluid. Due to the action of this high spring characteristic, the engine vibration around 5 Hz is suppressed. With respect to vibrations other than this, particularly the engine shake, since the general opening cross-sectional area of the orifice is not changed, there is no particular change and a predetermined vibration damping action is performed.

Further, in the invention according to claim 5, the orifice comprises a plurality of pores having a small opening cross-sectional area, and the sum of the opening cross-sectional areas of the plurality of pores is a predetermined value. Since the orifice is formed to have a value equal to or larger than the value of the general opening cross-sectional area of the orifice, the dilatant fluid in the main chamber and the sub chamber is
If an attempt is made to pass (flow) through the orifice composed of the plurality of pores in a state of vibration at an extremely low frequency around z, a great resistance will be applied there. As a result, the dilatant fluid is solidified in the vicinity of the entrance and exit of the pores, and the spring constant (spring characteristic) of the vibration damping device having such dilatant fluid is increased. As a result, the engine vibration around 5 Hz is suppressed. In addition, other vibrations, especially,
With respect to the engine shake that vibrates at around 10 Hz, the sum of the opening cross-sectional areas of all the pores is equal to or larger than the value of the general opening cross-sectional area of the predetermined orifice. There is no problem and a predetermined high attenuation characteristic can be obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment (first embodiment), which is a basic embodiment of the present invention, will be described with reference to FIGS. As shown in FIG. 1, the configuration of the present embodiment is such that a connecting fitting 6 connected to a vibrating body such as an engine, a holder 9 connected to a member on the vehicle body side, and the connecting fitting 6 and the holder 9 are connected to each other. An insulator 5 made of a rubber-like elastic body, and a main chamber 2 and a sub-chamber 3 which are provided in series below the insulator 5 in series and in which an incompressible fluid (liquid) is enclosed. An orifice 1 for circulating the liquid which is the incompressible fluid between the main chamber 2 and the sub chamber 3;
It is basically composed of an air chamber 7 into which air that is a compressive fluid is introduced, and a diaphragm 4 that partitions the air chamber 7 and the sub chamber 3 from each other.

With such a basic structure, the main chamber 2
The fluid that is enclosed in the sub chamber 3 and flows in the orifice 1 has a low viscosity and a high amplitude when it is vibrated at a low frequency and solidifies the fluid (liquid). A so-called dilatant fluid in which a phenomenon occurs is adopted. In particular, in the present embodiment, the above solidification phenomenon occurs when vibration of an extremely low frequency of about 5 Hz is input,
The antivibration device having the present dilatant fluid is filled with a fluid adjusted to have extremely high spring characteristics.

Further, the orifice 1 through which the dilatant fluid flows, as shown in FIGS. 1 and 2, is the main chamber 2.
The partition plate 8 for partitioning between the sub chamber 3 and the sub chamber 3 is vertically (straightly) provided in the central portion thereof. As described above, at least one of the main chamber side outlet portion 82 (see FIG. 1) and the sub chamber side outlet portion 83 (see FIG. 2) of the orifice 1 provided vertically is provided with a hat profile cap. 19 are provided. And this hat profile cap 19
As shown in FIG. 3, there is a space inside, and when the cap 19 is attached to the main chamber side outlet 82 or the sub chamber side outlet 83, the space is filled with the collision chamber 11. It is designed to be formed. Further, the side wall 155 of the space portion that forms the collision chamber 11 is formed.
Is provided with a plurality of through holes 15 having a small opening area. Each of the through holes 15 has a small opening area, but the total opening area of the through holes 15 is equal to or larger than the value of the general opening cross-sectional area of the orifice 1. Is set to the value of.

The cap 19 having such a structure is
As shown in FIG. 1, it is provided at the main chamber side outlet portion 82 of the orifice 1 or at the sub chamber side outlet portion 83 as shown in FIG. It should be noted that the dilatant effect can be obtained in a one-sided state at such outlets 82, 83 provided on either side. 1 and 2 are combined, that is, the main chamber side outlet portion 82 (see FIG. 1) and the sub chamber side outlet portion 83.
(See FIG. 2) and the collision chamber 11 and the like are both provided, the above-mentioned dilatant effect can be obtained in a two-effect state.

Next, a second embodiment (second embodiment) of this embodiment will be described with reference to FIGS. 4 to 7. The configuration of this embodiment is also basically the same as that of the first embodiment. The difference lies in the configuration around the collision chamber 11 provided near the orifice 1 and its outlet. That is, the orifice 1 of this embodiment has an annular shape as shown in FIG. 4, and specifically, as shown in FIGS. 4 to 7, it is between the main chamber 2 and the sub chamber 3. The partition plate 8 is formed in an annular shape around the peripheral edge of the partition plate 8. Then, at the main chamber side outlet portion or the sub chamber side outlet portion of the orifice 1 having these configurations, a collision chamber 11 formed of a space portion is formed, and
In the places facing the main chamber 2 side and the sub chamber 3 side,
A through hole 15 having a small opening is provided. As in the case of the first embodiment, the sum of the opening area of each of the through holes 15 is equal to or larger than the value of the general opening cross-sectional area of the orifice 1. It is set as shown.

Further, by providing the collision chamber 11 and the through hole 15 having such a structure at the outlet of the sub chamber, as shown in FIGS. 4 and 5, for example,
The dilatant effect is obtained for the input in the compression direction (bound direction) of the vibration isolator. Further, as shown in FIGS. 6 and 7, the dilatant effect can be obtained with respect to the input in the extension direction (rebound direction) of the vibration isolator by being provided at the outlet of the main chamber. There is. Further, in the case where the one formed at the main chamber side outlet portion and the one formed at the sub chamber side outlet portion are provided in a combined state, the dilatant effect in the two-effect state is obtained. Will be obtained. Therefore, the damping function based on the dilatant effect is exerted more strongly.

Next, the operation modes of the above-mentioned first and second embodiments having the above-mentioned configurations will be described. That is, when the liquid-filled type vibration damping device as shown in FIGS. 1, 2, and 4 is attached to a vibrating body such as an engine, vibration from the vibrating body side (not shown) causes the connecting fitting 6 to be vibrated. It is propagated to the insulator 5 made of a rubber-like elastic body through. Then, at the insulator 5, most of the propagated vibrations are absorbed and blocked. That is, most vibrations including engine idling vibrations are absorbed and blocked at the insulator 5. Further, with respect to the engine shake, which is a vibration (about 10 Hz) having a frequency lower than the engine idling vibration, the fluid (liquid) flowing in the orifice 1 is prevented from exhibiting dilatancy, and a predetermined damping characteristic is obtained. I am trying to show it. That is, the engine shake is suppressed by exhibiting the predetermined damping characteristic (high damping characteristic).

Next, with respect to the engine idling vibration or the vibration at an extremely low frequency of about 5 Hz, which is a further lower frequency than the engine shake, etc., the spring constant of the engine mount device (vibration isolator) ( The spring characteristic) is increased to physically suppress the vibration at the extremely low frequency. That is, in the first and second embodiments, the fluid (liquid) sealed in the main chamber 2 and the sub chamber 3 is subjected to vibration of extremely low frequency and high amplitude. At this time, the property of the fluid is a so-called dilatant fluid that is solidified from a liquid state to a high viscosity state, and such a dilatant fluid is caused to rapidly flow in the orifice 1 and thereby the fluid Is hardened to harden the spring characteristics. As a result, the above-mentioned 5H that occurs during engine cranking, sudden start of the vehicle, or sudden acceleration, etc.
It is supposed to suppress engine vibrations at extremely low frequencies around z.

Specifically, for example, in the first embodiment, as shown in FIGS. 1 and 2, the dilatant fluid excited by the vibration of an extremely low frequency of about 5 Hz is fed from the orifice 1 to the main chamber. When flowing toward the side outlet 82 or the sub chamber side outlet 83, the direction of the flow of the dilatant fluid is changed by about 90 ° here. Then, as shown by the arrows in FIGS. 1 and 2, the fluid flows into the through hole 15 formed of a small opening. Due to these series of flow actions, at the collision chamber 11,
The fluid flow becomes turbulent and receives internal resistance. As a result, the dilatant fluid in the collision chamber 11 receives a compressive force, and the compressive force causes a solidification phenomenon. Therefore, the spring constant (spring characteristic) of the vibration isolator becomes high, and
The engine vibration before and after z is suppressed by the action of this high spring characteristic.

Particularly, as for such a dilatant effect, the structure shown in FIGS.
By being provided at both the outlets of the secondary chamber 2 and the outlet side of the sub chamber 83, it is possible to obtain the two-effect state, and the above-mentioned vibration damping effect becomes more prominent. Also in the second embodiment, the collision chamber 1 is provided at the main chamber side outlet portion or the sub chamber side outlet portion of the annular orifice 1.
By providing 1 and the through hole 15, the same dilatant effect is formed. As a result, a high spring characteristic is formed due to the solidification phenomenon of the dilatant fluid, which suppresses the engine vibration at an extremely low frequency of about 5 Hz.

Next, a third embodiment (third embodiment) of this embodiment will be described with reference to FIG. The basic configuration of this embodiment is the same as that of the first and second embodiments. The difference lies in the resistance portion formed in a part of the orifice 1. That is, as shown in FIG. 8, the resistance portion of the present embodiment is provided in a part of the partition plate 8 that partitions the main chamber 2 and the sub chamber 3 from each other. The space 88 connected to
And the collision chamber 11 formed of the mesh screen 99 installed in the space 88, and the through hole 15 provided at the main chamber side wall portion 84 and the sub chamber side wall portion 85 of the collision chamber 11. It is based on that.

In such a basic structure, the mesh screen 99 is made of steel wool or the like, and when the dilatant fluid flows in the collision chamber 11 in which the mesh screen 99 is installed. A resistance is added to the flow of the fluid, and the fluid receives internal pressure and solidifies.
Further, the through hole 1 formed at the wall portions 84 and 85.
No. 5 is similar to the above first and second embodiments, each opening area has a small value,
The total area of the openings of the through holes 15 is formed to be equal to or larger than the value of the general opening cross-sectional area of the predetermined orifice. Therefore, in the present embodiment, the collision chamber 11 and the through hole 1 are
By the action of 5, when the dilatant fluid excited by the vibration at an extremely low frequency of about 5 Hz passes through the main through hole 15 and the collision chamber 11, the fluid is solidified by the dilatant action. As a result, the spring constant (spring characteristic) of the anti-vibration device is increased, and engine vibration around 5 Hz is suppressed at the anti-vibration device. For vibrations other than the frequency of about 5 Hz, particularly for engine shake, the sum of the opening areas of the through holes 15 is equal to or larger than the value of the general opening cross-sectional area of the predetermined orifice. Since it is set so that a predetermined high attenuation characteristic can be obtained.
Therefore, the vibration related to the engine shake is blocked at the anti-vibration device like the conventional one.

Next, a fourth embodiment (fourth embodiment) will be described with reference to FIG. The basic structure of this embodiment is the same as that of the first to third embodiments. The difference is that as shown in FIG.
This is that the resistance portion is formed by a mesh-shaped screen 99 installed in the orifice 1. That is, the mesh-shaped screen 99 made of steel wool or the like is installed in the orifice 1 which connects the main chamber 2 and the sub chamber 3 and is formed so as to have a predetermined general opening cross-sectional area. It is composed of the following configurations. Therefore, when the dilatant fluid excited by the vibration of an extremely low frequency of around 5 Hz flows in the orifice 1 having such a structure, the fluid receives resistance at the mesh screen 99, It becomes turbulent. As a result, the fluid receives internal pressure and solidifies. As a result, the spring constant (spring characteristic) of the vibration isolator becomes high. As a result, the engine vibration having an extremely low frequency of about 5 Hz is suppressed.
In the present embodiment, as in the case of the first to third embodiments, vibrations of other frequencies, especially engine shake, do not cause dilatancy in the fluid in the orifice 1 in particular. , The solidification phenomenon of fluid (liquid) does not occur. Therefore, similar to the conventional one, a predetermined attenuation characteristic can be obtained.

Next, a fifth embodiment (fifth embodiment) of this embodiment will be described with reference to FIG. The basic structure of this embodiment is the same as that of the first to fourth embodiments. The difference is in the resistance portion as shown in FIG. That is, the resistance portion of the present embodiment is basically composed of a plurality of pores 16 provided at the partition plate 8 that partitions the main chamber 2 and the sub chamber 3 from each other. In such a basic configuration, the pores 16 are formed so as to connect the main chamber 2 and the sub chamber 3 with each other, and the cross-sectional shape thereof is a circular or rectangular slit shape. It consists of Each of the pores 16 has a small opening cross-sectional area, but the sum of the opening cross-sectional areas is the sum of the general opening cross-sectional areas of the predetermined orifices in the liquid filled type vibration damping device. It is formed so as to have a value equal to or more than the value. That is, the aggregate of the pores 16 forms the predetermined orifice 1.

By adopting such a structure, in this embodiment, the dilatant fluid in the main chamber 2 and the sub-chamber 3 is excited by vibration at an extremely low frequency of about 5 Hz, and the pores are formed. When attempting to flow at 16, the fluid experiences a great resistance at the pores 16. As a result, the dilatant fluid is subjected to pressure in the vicinity of the entrance / exit of the pores 16 and is thereby solidified. Due to such a solidification phenomenon of the dilatant fluid, the spring constant (spring characteristic) of the vibration isolator becomes high, and the engine vibration at around 5 Hz is suppressed. For vibrations other than this, particularly for engine shake, the sum of the opening cross-sectional areas of each of the pores 16 should be equal to or greater than the value of the general opening cross-sectional area of the predetermined orifice. Therefore, there is no particular problem and a predetermined attenuation characteristic can be obtained.

[0031]

According to the present invention, a connecting metal fitting attached to the vibrating body side, a holder mounted to a member or the like on the vehicle body side, and a function for blocking vibration from the vibrating body between the connecting metal fitting and the holder. And a main chamber and a sub-chamber, which are provided in series with the insulator and in which the non-compressible fluid is sealed, and the incompressible fluid between the main chamber and the sub-chamber. An orifice for flowing, an air chamber into which a compressive fluid such as air is introduced,
A diaphragm that partitions between the air chamber and the sub chamber;
Regarding the liquid-filled type vibration damping device consisting of, a non-compressible fluid filled in the main chamber, the sub chamber, and the orifice is under a predetermined frequency and under a condition having a predetermined amplitude, It is composed of a dilatant fluid in which a fluid (liquid) solidification phenomenon occurs, and also comprises a collision chamber for changing the flow of the fluid largely to a part of the orifice through which the dilatant fluid flows, and a small opening. A structure in which a resistance portion including a plurality of through holes formed so that the total opening area of each opening is equal to or larger than the value of the general opening cross-sectional area of a given orifice is provided. Therefore, the dilatant fluid receives a large flow resistance in the collision chamber or the like against a vibration input having an extremely low frequency of about 5 Hz and a high amplitude. Become a Rukoto, thereby, it adapted to receive the internal pressure. As a result, a solidification phenomenon of the fluid (liquid) occurs with respect to the vibration input of about 5 Hz, and the spring constant (spring characteristic) of the vibration isolator having the dilatant fluid becomes high. The engine vibration having a frequency of about 5 Hz has been suppressed.

In the present invention, since the total opening area of each of the above-mentioned through holes is formed to be equal to or larger than the value of the general opening cross-sectional area of the predetermined orifice, it is possible to obtain other values. A predetermined damping characteristic has been ensured for frequency vibration, particularly for engine shake.
Therefore, in the present invention, it becomes possible to exert a vibration damping function on the engine shake by forming a high damping characteristic, as in the conventional liquid-filled type vibration damping device. With respect to vibration of extremely low frequency and high amplitude, it has become possible to exert a vibration damping function by hardening the spring characteristic by the dilatant effect of fluid. That is, in the present invention, in addition to the various functions of the conventional liquid-filled type vibration damping device, an extremely low frequency of about 5 Hz, which occurs when the engine is cranked or when the vehicle is suddenly started or suddenly accelerated, High-amplitude engine vibration can now be suppressed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the overall configuration of a main chamber side outlet portion of a first embodiment according to the present invention in which a resistance portion is provided.

FIG. 2 is a vertical cross-sectional view showing the overall structure of the first embodiment of the present invention in which a resistance portion is provided at the outlet of the sub chamber.

3A and 3B are a front view and a half sectional view showing an overall configuration of a cap forming a resistance portion in the first embodiment.

FIG. 4 is a vertical sectional view showing the overall configuration of a second embodiment according to the present invention.

FIG. 5 is a front view showing an overall configuration of an orifice which is a main part of a second embodiment and a resistance portion formed around the orifice.

FIG. 6 is a plan view showing an overall configuration of an orifice which is a main part of a second embodiment and a resistance part formed around the orifice.

FIG. 7 is a vertical cross-sectional view showing an entire configuration of an orifice which is a main part of a second embodiment and a resistance part formed around the orifice.

FIG. 8 is a partial cross-sectional view showing a configuration of a main part of a third embodiment according to the present invention.

FIG. 9 is a partial cross-sectional view showing the configuration of a main part of a fourth embodiment according to the present invention.

FIG. 10 is a partial cross-sectional view showing a configuration of a main part of a fifth embodiment according to the present invention.

FIG. 11 is a vertical cross-sectional view showing the overall configuration of a conventional example.

[Explanation of symbols]

 1 Orifice 11 Collision chamber 15 Through hole 155 Side wall 16 Pore 19 Cap 2 Main chamber 3 Sub chamber 4 Diaphragm 5 Insulator 6 Connecting metal fitting 7 Air chamber 8 Partition plate 82 Main chamber side outlet part 83 Sub chamber side outlet part 84 Wall part ( Main chamber side wall part) 85 Wall part (sub chamber side wall part) 88 Space part 9 Holder 99 Screen (mesh screen)

Claims (5)

[Claims] 1. A coupling fitting attached to the vibrating body side, a holder mounted to a member or the like on the vehicle body side, and an insulator between the coupling fitting and the holder that exerts a function of blocking vibration from the vibrating body. A main chamber and a sub-chamber, which are provided in series with the insulator and in which the non-compressible fluid is enclosed, an orifice for flowing the non-compressible fluid between the main chamber and the sub-chamber, and air. In a liquid-filled type vibration damping device including an air chamber into which an equal-compressible fluid is introduced and a diaphragm separating the air chamber and the sub-chamber, an incompressible type enclosed in the main chamber and the sub-chamber The fluid is composed of a dilatant fluid, and when the dilatant fluid flows through the orifice in at least a part of the orifice, there is no resistance to the flow. A liquid-filled type vibration damping device having a structure in which a resistance portion configured as described above is provided. 2. The liquid filled type vibration damping device according to claim 1, wherein the resistance portion is provided on at least one of the main chamber side outlet portion and the sub chamber side outlet portion of the orifice. There is a collision chamber consisting of a space in which the flow direction of the dilatant fluid is largely changed, and the one provided on the side wall of the collision chamber, each opening area has a small value, and the sum thereof is ,
A liquid-filled type vibration damping device comprising: a plurality of through holes formed to have a value equal to or larger than a value of a cross-sectional area of a general opening cross section of the orifice. 3. The liquid-filled type vibration damping device according to claim 1, wherein the resistance portion is provided on a partition plate that partitions the main chamber and the sub chamber from each other. A collision chamber formed by a space portion connected to and a screen installed in the space portion, and a wall portion of the collision chamber, the opening area of each has a small value, and A plurality of through holes formed so that the total has a value equal to or greater than the value of the cross-sectional area of the general opening cross-section of the predetermined orifice in the liquid-filled type vibration damping device;
A liquid-filled type vibration damping device, characterized in that 4. The liquid-filled type vibration damping device according to claim 1, wherein the resistance portion is provided in an orifice so that a turbulent flow is generated in the flow of the dilatant fluid flowing in the orifice. A liquid-filled type vibration damping device, characterized in that it comprises a screen formed on. 5. The liquid filled type vibration damping device according to claim 1, wherein each of the resistance portions has a small opening cross-sectional area, and the sum of the resistance portions has a predetermined value forming a liquid filled type vibration damping device. A liquid-filled type vibration damping device comprising a plurality of pores formed so as to have a value equal to or larger than a value of a cross-sectional area of a general opening cross-section of an orifice.