JP3498234B2 - Liquid filled type vibration damping device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled type vibration damping device in which a vibration damping effect can be obtained based on the flow of a fluid (liquid) sealed inside. And in particular,
The present invention relates to a liquid-filled type vibration damping device in which a rubber film-like flexible member provided on a main chamber side can have a development area as wide as possible. 2. Description of the Related Art Among vibration damping devices, especially in engine mounts for automobiles and the like, an engine which is a power source is operated in various manners from an idling operation state to a maximum rotation speed. Because it is used in situations, it must be able to handle a wide range of frequencies. Therefore, a so-called liquid-filled engine mount (vibration isolator) in which two liquid chambers are provided inside and are connected by an orifice has already been devised and known. Further, in such a liquid-filled type vibration damping device, in order to cut off vibration related to engine noise such as muffled sound, which is a vibration in a high frequency range, it is formed of a rigid body that partitions between a main chamber and a sub chamber. Of the partition plate,
There is one in which a flexible member made of a rubber film-like elastic body is provided at the center thereof. By the action of the rubber film-like flexible member, a rise in the liquid pressure in the main chamber caused by a relatively high frequency vibration of about 100 Hz to 600 Hz is absorbed, and the whole vibration damping device in the high frequency range is absorbed. A low dynamic spring constant is to be achieved. [0003] In the above-mentioned conventional apparatus, an orifice for connecting the main chamber and the sub-chamber is provided in an annular shape around the partition plate. Is what it is. The rubber film-like flexible member is provided concentrically with the ring in the ring of the ring-shaped orifice. Therefore, the area of the rubber film-like flexible member is naturally restricted, and cannot take a very large area. As a result, a rubber film-like flexible member (rubber film) having a smaller diameter than the capacity of the main chamber (liquid chamber) is provided, and there is a concern that the hydraulic pressure in the main chamber cannot be sufficiently absorbed. is there. Further, there is a possibility that the life of the rubber film against repeated deformation may not be sufficiently obtained. In order to solve such a problem, an object of the present invention is to provide a liquid-filled type vibration damping device capable of sufficiently securing a pressure receiving area of a rubber film (flexible member). The purpose (issue). [0004] In order to solve the above problems, the present invention takes the following measures. That is, an upper connecting member attached to the vibrating body side, a lower connecting member attached to the vehicle body side, an insulator between these upper and lower connecting members for absorbing and blocking vibration from the vibrating body, and an insulator connected in series to the insulator. And a main chamber and a sub-chamber in which a liquid as an incompressible fluid is sealed, an annular orifice connecting between the main chamber and the sub-chamber, and A partition plate for partitioning between the sub-chamber and an air chamber formed below the sub-chamber through a rubber film-like diaphragm;
With respect to the liquid-filled type vibration damping device consisting of: at the above-mentioned partition plate, or between the partition plate and the main room and facing the main room, it is possible to cope with fluctuations in liquid pressure in the main room. And a flexible member which is deformed by a predetermined amount and is installed in a state where the flexible member is decentered (offset) by a predetermined amount with respect to a center point of the annular orifice. I decided to take it. [0005] By adopting such a configuration, the device of the present invention has the following effects.
In other words, among the vibrations input to the liquid-filled type vibration damping device, low-frequency vibrations related to idling vibration or engine shake, etc., are sealed in the action of the insulator and in the main chamber and the sub-chamber. The absorption and shutoff of the liquid are performed by the action of the liquid, and the flow of the liquid in the orifice connecting these two liquid chambers. Further, in the present invention, a rubber film-like flexible member is provided at the bottom of the main chamber, so that the function (vibration) of the rubber film-like flexible member is provided. Accordingly, various anti-vibration functions are exhibited. That is, in response to vibration of a specific frequency input to the liquid in the main chamber via the insulator, the rubber film-like flexible member provided at the bottom of the main chamber is displaced (deformed). By doing so, it is possible to avoid an increase in the hydraulic pressure in the main chamber, thereby forming a low dynamic spring constant (low dynamic spring characteristic) for the vibration of the specific frequency. As a result, a so-called muffled sound, which is a problem as a vibration in a high frequency range, is cut off. In particular, according to the present invention, the rubber film-like flexible member is provided in a state where the orifice formed in an annular shape is decentered by a predetermined amount with respect to the center point of the annular shape. Therefore, the area of the rubber film-like flexible member which receives pressure (liquid pressure) from the liquid in the main chamber, that is,
The pressure receiving area can be made wider in the main chamber. As a result, it is possible to improve the hydraulic pressure absorbing capacity of the rubber film-like flexible member, and to improve the durability of the rubber film-like flexible member against repeated deformation (displacement) due to vibration. Will be able to do that. Further, in the negative pressure introduction type liquid-filled type vibration damping device, the diaphragm formed by the rubber film-like flexible member can have a large area, so that the diaphragm can be enlarged and contracted as the equilibrium chamber expands and contracts. The durability of the resulting rubber film-like flexible member (diaphragm) against repeated deformation can be improved. In addition to these, the value of the generated force formed by the introduction of a negative pressure into the equilibrium chamber or the like and transmitted to the liquid in the main chamber through the diaphragm can be made large. become. An embodiment of the present invention will be described with reference to FIGS. 1 to 3. Although the present invention relates to an embodiment of the present invention, as shown in FIG. 1, the configuration is such that an upper connecting member 91 attached to the vibrating body side, a lower connecting member 95 attached to the vehicle body side, these upper connecting member 91 and the lower connecting member 95, an insulator 4 for blocking vibration from the vibrating body, a main chamber 5 and a sub-chamber 6 provided in series with the insulator 4 and filled with an incompressible fluid (liquid); An annular orifice 3 connecting the main chamber 5 and the sub-chamber 6; a partition plate 2 for separating the main chamber 5 and the sub-chamber 6;
Or the partition 2 and the main chamber 5
And the rubber-film-shaped flexible members 1 and 1 ′ provided at a position facing the main chamber 5 (see FIG. 2) and the sub-chamber 6.
Air chamber 8 formed below diaphragm 7 through diaphragm 7
And that is basically composed of In such a basic configuration, the flexible members 1 and 1 'made of a rubber-like elastic body (rubber film-like member) and the like provided at a substantially central portion of the partition plate 2 are provided.
It is designed to be deformed in accordance with a change in the hydraulic pressure in the main chamber 5. In particular, in the present embodiment shown in FIG.
It is designed to vibrate (deform) with respect to vibration in a high frequency range of about z to 600 Hz. As shown in FIGS. 1 and 3, such a rubber film-like flexible member 1 is provided at a bottom portion of the main chamber 5 by a predetermined amount so as to avoid the inlet 31 of the annular orifice 3. It is designed to be installed in an eccentric state. That is,
It is designed to be provided with the offset amount (E). Therefore, the bottom of the main chamber 5 receives the maximum liquid pressure of the liquid in the main chamber 5. On the basis of the main chamber 5 and the like having such a configuration, a sub-chamber 6 connected to the main chamber 5 through an annular orifice 3 and an air chamber 8 formed in the sub-chamber 6 via a diaphragm 7 are provided. These components form a liquid-sealing type vibration isolator. Next, the operation and the like of the embodiment having such a configuration will be described. That is, most of the vibration input to the upper connecting member 91 connected to the vibrator is absorbed by the insulator 4 and cut off. Among those (vibrations) that were not blocked at the insulator 4, those related to idling vibration are absorbed and blocked by the resonance phenomenon of the liquid sealed in the main chamber 5, and the like. Become. Further, with respect to the engine shake which is a vibration of a lower frequency than the idling vibration, the liquid in the main chamber 5 is caused to flow to the sub-chamber 6 through the orifice 3 so as to exhibit a damping function, by this,
The vibration related to the engine shake is suppressed. [0010] Compared to the vibration in the low frequency range, the vibration in the relatively high frequency range is about 100 Hz to 600 Hz.
With respect to a vibration input of Hz, the rise of the liquid pressure in the main chamber 5 is avoided by displacing (deforming) the rubber film-like flexible member 1 provided on the bottom surface of the main chamber 5. As a result, a low dynamic spring constant (low dynamic spring characteristic) is formed for the vibration of the specific frequency. In other words, vibration related to so-called muffled sound, which is a problem as vibration in a high frequency range, is cut off. In the present embodiment, the rubber film-like flexible member 1 is formed such that the orifice 3 formed in an annular shape has a predetermined amount of eccentricity (E) with respect to the center point of the annular shape.
The area of the rubber film-shaped flexible member 1 that receives the pressure (liquid pressure) from the liquid in the main chamber, that is, the pressure receiving area, is increased in the main chamber 5. You can take it. As a result, the hydraulic pressure absorbing ability of the rubber film-like flexible member 1 can be improved, and the rubber film-like flexible member 1 can be improved.
However, the durability against repeated deformation (displacement) due to vibration can be improved. Next, another embodiment having such an eccentric rubber film-like flexible member will be described with reference to FIG. In this embodiment, an equilibrium chamber 13 formed by a rubber film-like flexible member, that is, a diaphragm 1 ′ is provided near the bottom of the main chamber 5. Pressure or atmospheric pressure,
The liquid is introduced alternately in synchronization with vibration of a specific frequency such as idling vibration, thereby vibrating the diaphragm 1 ′ forming the equilibrium chamber 13. As a result, the hydraulic pressure of the liquid in the main chamber 5 is increased. The present invention relates to a negative pressure introduction type liquid filled type vibration damping device that controls fluctuation. In such a negative pressure introducing type liquid filled vibration isolator, the diaphragm 1 is provided between the partition plate 2 and the main chamber 5 and forms an equilibrium chamber 13 into which a negative pressure or the like is introduced. 2 and 3, the annular orifice 3 is provided with a predetermined amount of offset (E) with respect to the center point of the annular ring. As a result, the diaphragm 1 'forming the equilibrium chamber 13 is
The orifice 3 exists over a wide range at the bottom of the main chamber 5 while avoiding the suction port 31 of the orifice 3.
That is, the diaphragm 1 ′ can be formed large, and the durability against repeated deformation of the diaphragm 1 ′ accompanying expansion and contraction of the equilibrium chamber 13 can be improved. The generated force, that is, the force for controlling the fluctuation of the hydraulic pressure in the main chamber 5 can be increased. According to the present invention, the upper connecting member attached to the vibrating body, the lower connecting member attached to the vehicle body, and the upper connecting member and the lower connecting member provided between the upper connecting member and the lower connecting member. An insulator that absorbs and blocks vibrations of the main body, a main chamber and a sub-chamber, which are provided in series with the insulator, and in which a liquid that is an incompressible fluid is sealed; An annular orifice connecting between them, and a partition plate for partitioning between the main chamber and the sub-chamber, and an air chamber formed below the sub-chamber through a rubber film-like diaphragm, With respect to the liquid-filled type vibration damping device consisting of: at the above-mentioned partition plate, or between the partition plate and the main room and facing the main room, it is possible to cope with fluctuations in liquid pressure in the main room. Provide a flexible member that deforms In addition, since the flexible member is installed with a predetermined amount of eccentricity (offset) with respect to the annular center point of the annular orifice, idling vibration is provided. Alternatively, with respect to low-frequency vibrations related to an engine shake, etc., the action of the above-described insulator, the action of the liquid sealed in the main chamber and the sub-chamber, and the action of the flow of the liquid in the orifice connecting between these two liquid chambers. Thus, absorption and blocking can be performed. At the same time, for vibration of a specific frequency in the high frequency range,
By displacing (deforming) the flexible member provided at the bottom portion of the main chamber, an increase in the hydraulic pressure in the main chamber is avoided, and thus, the low-movement against the vibration of the specific frequency is prevented. A spring constant (low dynamic spring characteristic) can be formed. As a result, it is possible to cut off vibration related to so-called muffled sound, which is a problem as vibration in a high frequency range. In particular, according to the present invention, the flexible member is provided in a state where the orifice formed in an annular shape is decentered by a predetermined amount with respect to the center point of the annular shape. The area of the flexible member that receives the pressure (liquid pressure) from the liquid in the room, that is, the pressure receiving area, can be made wider in the main chamber. As a result, the fluid pressure absorbing capacity of the flexible member can be improved, and the durability of the flexible member against repeated deformation (displacement) due to vibration can be improved. became. In addition, in the negative pressure introduction type liquid filled type vibration damping device, the value of the generated force formed in the equilibrium chamber can be made large in addition to the improvement of the durability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing the overall configuration of the present invention. FIG. 2 is a longitudinal sectional view showing an overall configuration of another embodiment of the present invention. FIG. 3 is a cross-sectional view showing a structure around a flexible member according to the present invention. [Description of Signs] 1 Flexible member (rubber film-like flexible member) 1 'Diaphragm (Flexible member) 13 Balancing chamber 2 Partition plate 3 Orifice 31 Suction port 4 Insulator 5 Main chamber 6 Sub chamber 7 Diaphragm 8 Air chamber 91 Upper connecting member 95 Lower connecting member

Claims (1)

(57) [Claim 1] An upper connecting member attached to the vibrating body side, a lower connecting member attached to the vehicle body side, and a vibration between the upper and lower connecting members is provided between the upper and lower connecting members to absorb the vibration from the vibrating body. And an insulator that is provided in series with the insulator, and connects the main chamber and the sub-chamber in which a liquid that is an incompressible fluid is sealed, and connects the main chamber and the sub-chamber. An annular orifice, and a partition plate for partitioning between the main chamber and the sub-chamber, and an air chamber formed below the sub-chamber through a rubber film-like diaphragm,
In the liquid-filled vibration isolator consisting of: at the above-mentioned partition plate, or between the partition plate and the main room and facing the main room, it is possible to cope with fluctuations in liquid pressure in the main room. And a flexible member which is deformed by a predetermined amount with respect to the annular center point of the annular orifice. Liquid filled type vibration damping device.