JP3560038B2 - Liquid filled type vibration damping device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-sealed type vibration damping device that can obtain a vibration-damping effect based on the flow of a fluid (liquid) sealed therein, and is particularly exhibited with the flow of a liquid. The present invention relates to a liquid-filled type vibration damping device in which vibration damping characteristics can be switched to a plurality of stages by using a vibration device having a simple structure driven by an engine suction negative pressure.
[0002]
[Prior art]
Among the vibration isolators, especially in the case of engine mounts for automobiles, the engine, which is the power source, is used under various conditions from the idling operation state to the maximum rotation speed. Therefore, it must be able to handle a wide range of frequencies. In recent years, engine mounts have been tuned for the purpose of cutting off noise caused by vibration in a relatively high frequency range. In order to cope with such a plurality of conditions, a so-called voice coil type in which a liquid chamber is provided inside, and a vibrator made of a voice coil or the like vibrating at a specific frequency is further provided in the liquid chamber. The liquid-filled type vibration damping device has already been devised, and is known, for example, from Japanese Patent Application Laid-Open No. 5-149369. However, in these known devices, a plurality of liquid chambers are provided, a movable piece such as a piston is provided in the liquid chamber, and further, a voice coil for driving the movable piece is provided. Its structure is complicated. Therefore, these known devices have a problem that they have to be heavier as a whole as a vibration isolator because they have many components including a vibrating coil and a permanent magnet. In order to solve such a problem, a vibration device including a simple mechanism driven by the negative pressure of the engine is provided to cut off various vibrations including idling vibration. An application has already been filed by the present applicant as shown in FIG. 2 (see Japanese Patent Application No. 8-287524).
[0003]
[Problems to be solved by the invention]
In this case, the vibration isolating mechanism 10 is formed based on an equilibrium chamber 130 provided through a diaphragm 150 in the insulator 20 and the main chamber 110. Then, the engine suction negative pressure or the atmospheric pressure is introduced into the equilibrium chamber 130 by the switching means 30 that performs a switching operation based on the control action of the control means 50. In particular, when shutting off vibration at the time of engine idling, the switching valve 310 forming the switching means 30 is opened and closed in accordance with the frequency at the time of engine idling, whereby the engine suction negative pressure and the atmospheric pressure are reduced. It is to be alternately introduced into the equilibrium chamber 130. By the way, when the switching valve 310 is opened and closed at a predetermined cycle (frequency) during the introduction of the negative pressure and the atmospheric pressure, the pressure fluctuation in the equilibrium chamber 130 at that time, that is, the excitation force The fluctuation state may include high frequency component noise. Then, the noise of the high-frequency component propagates a complicated high-frequency vibration sound into the vehicle compartment instead of the idling vibration. In order to solve such a problem, a liquid-filled type vibration damping device in which the pressure fluctuation in the equilibrium chamber does not have a high-frequency component which is a problem in a vehicle when a negative pressure is introduced and when an atmospheric pressure is introduced. It is an object of the present invention to provide a device.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has taken the following measures. That is, an upper connecting member attached to the vibrating body, a lower connecting member attached to the vehicle body side, an insulator interposed between the upper connecting member and the lower connecting member for absorbing and blocking vibration from the vibrating body, and the insulator Are provided in series with each other, and a main chamber in which a liquid that is an incompressible fluid is enclosed, and a sub-chamber in which the main chamber and the liquid are connected through an orifice so as to flow, An anti-vibration mechanism, which is formed through a diaphragm in the main chamber and includes an equilibrium chamber formed so that one of atmospheric pressure and negative pressure is introduced. and switching means for switching operates to introduce either one of the one of the vibration isolating mechanism of the balancing chamber to a negative pressure or atmospheric pressure, and controls the switching operation of said switching means, said A state continuously introducing one of a negative pressure and atmospheric pressure衡室, and a state in which introduced alternately in a state of being synchronized with negative pressure and the atmospheric pressure to the vibration of the vibrator to the equilibrium chamber Control means, comprising a diaphragm forming the equilibrium chamber, the periphery of which is made of an elastic diaphragm formed of a rubber-like member, and the center of which is made of the rubber. A configuration in which the elastic member has a form having a predetermined mass in the elastic member is adopted.
[0005]
By adopting such a configuration, the device of the present invention exhibits the following operation. That is, with respect to idling vibration, by operating the switching means, a negative pressure or an atmospheric pressure is alternately introduced into the equilibrium chamber at a specific frequency. That is, by operating the switching means at a specific frequency, the pressure (volume) in the equilibrium chamber is changed, whereby the hydraulic pressure fluctuation in the main chamber caused by idling vibration input through the insulator. So that it absorbs. As a result, the dynamic spring constant of the spring system formed by the insulator and the main vibration isolator is reduced.
[0006]
In particular, in this case, in the device of the present invention, a mass having a predetermined mass is provided at the diaphragm forming the equilibrium chamber, and a portion of the mass is caused by the idling vibration of the equilibrium chamber. Resonance occurs in response to a change in volume (operation) in a state synchronized with. That is, a resonance system for idling vibration is formed by a mass having a predetermined mass and a spring made of an elastic diaphragm provided around the mass. Therefore, the generated force (vibration energy) in the vibration isolating mechanism for idling vibration shows a large value due to the resonance phenomenon of the diaphragm with the mass. That is, only the generated energy at the natural frequency (fn) related to the target idling vibration has a sharp peak value. Therefore, in other frequency ranges, the generated energy is relatively reduced. As a result, in a practically generated energy region, noise and the like, which are vibrations of high frequency components, are extremely reduced. Therefore, it is possible to prevent the occurrence of high-frequency vibration and the like that occur in connection with the blocking of idling vibration, which has been a concern in the related art.
[0007]
Further, with respect to the engine shake which is a vibration of a lower frequency than the idling vibration, the liquid is caused to flow in the orifice connecting between the main chamber and the sub-chamber. Shall be absorbed and blocked. That is, since the vibration related to the engine shake has a frequency of about 10 Hz, it is difficult to cut off the vibration by reducing the dynamic spring constant. Therefore, in the present invention, a constant negative pressure is continuously introduced into the equilibrium chamber forming the vibration isolation mechanism, and a diaphragm with a mass forming the equilibrium chamber is pulled down, and the equilibrium chamber is lowered. Volume to zero. Thus, the diaphragm with the mass provided in the main chamber is not operated. In such a state, when the vibration from the vibrating body is propagated to the insulator, the lower surface of the insulator vibrates according to the vibration, and the liquid in the main chamber is positively moved to the sub-chamber side. Operates to flow. As a result, the liquid in the main chamber flows to the sub chamber through the orifice. A predetermined damping force is generated by viscous resistance caused by the flow of the liquid, and the engine shake is suppressed (attenuated) by the damping force.
[0008]
On the other hand, with respect to high frequency vibration of about 100 Hz to 600 Hz which causes a muffled sound which is a problem during running of the vehicle, the switching means is operated to open the equilibrium chamber to the atmosphere. As a result, atmospheric pressure is introduced into the equilibrium chamber, and the diaphragm with the mass forming the equilibrium chamber freely operates (vibrates). As a result, the liquid in the main chamber flows relatively freely in the main chamber in response to the vibration input from the insulator side. As a result, the dynamic spring constant of the spring system formed by the entire vibration isolator can be kept low. Therefore, the effect of blocking vibration in a high frequency range is enhanced. As described above, according to the present invention, a plurality of types of vibrations are absorbed and cut off by the operation of the switching means including the switching valve and the like.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIG. Although related to the embodiment of the present invention, the configuration is such that an upper connecting member 6 attached to a vibrating body, a lower connecting member 9 attached to a member or the like on a vehicle body side, and an upper connecting member 6 and a lower connecting member 9 An insulator 2 that is interposed between the insulator 2 and absorbs and blocks vibration from the vibrating body, and a main chamber 12 and a sub chamber 16 that are provided in series with the insulator 2 and are filled with a liquid that is an incompressible fluid. A negative pressure or a pressure is applied to a vibration isolating mechanism 1 including a liquid chamber and the like and a balancing chamber 13 which forms a part of the vibration isolating mechanism 1 and is provided in the main chamber 12. Switching means 3 for performing a switching operation so as to introduce one of the atmospheric pressures continuously or alternately in synchronization with engine vibration, and controlling the switching operation of the switching means 3 And control means 5, in which the basic in that it consists of.
[0010]
In such a basic configuration, the insulator 2 is made of a rubber-like elastic material such as a vibration-proof rubber material, and one end surface of the insulator 2 is integrally connected to the upper connecting member 6 by a vulcanization bonding means or the like. It is something that is to be done. The vibration isolating mechanism 1 provided in series with the insulator 2 is provided below the insulator 2 continuously with the insulator 2 and has a main chamber 12 filled with liquid. And an equilibrium chamber 13 formed in the main chamber 12 at a lower portion thereof through a diaphragm 11 having a mass and into which a negative pressure or an atmospheric pressure is introduced; A sub-chamber 16 in which liquid is sealed, and an orifice 15 connecting between the main chamber 12 and the sub-chamber 16, similarly to the main chamber 12. It is provided below the sub-chamber 16 via a diaphragm 17 and basically comprises an air chamber 18 into which the atmosphere is always introduced.
[0011]
The structure of the diaphragm 11 with the mass, which forms a part of the vibration isolating mechanism 1 having such a structure, will be described. That is, as shown in FIG. 1, the diaphragm 11 with the main mass is provided with a mass 111 having a predetermined mass at the center thereof, and is provided at a peripheral portion where the mass 111 is provided. An elastic diaphragm 115 made of a rubber member is provided. The elastic diaphragm 115 forms a soft spring constant and can be easily deformed in the vertical direction in FIG. A part of such a rubber-like elastic member entirely surrounds the periphery of the mass 111. As described above, in the present embodiment, the predetermined value is determined by the mass (M) of the mass 111 and the spring constant (K) of the elastic diaphragm (elastic diaphragm) 115 provided around the mass 111. A resonance system having a natural frequency (fn) is formed. The natural frequency (fn) of the resonance system is set to match the vibrating body in which the vibration isolator is installed, that is, the idling vibration of the mounted engine.
[0012]
Next, the switching means 3 which operates so as to introduce the negative pressure or the atmospheric pressure into the equilibrium chamber 13 having such a configuration while appropriately switching the pressure is constituted by a switching valve 31 such as a three-way valve and the like. And a solenoid 32 for driving the valve 31. A throttle valve 35 for adjusting the introduction speed of the atmospheric pressure with the introduction speed of the negative pressure is provided on the side of the atmospheric pressure introduction port of the switching valve 31 having such a configuration. I have.
[0013]
Next, the control means 5, which controls the switching operation of the switching means 3 having such a configuration, comprises a microcomputer or the like formed on the basis of arithmetic means such as a microprocessor unit (MPU), and includes an engine and the like. The vibration from the vibrating body is detected, and the switching operation of the switching means 3 is controlled in accordance with the vibration.
[0014]
Next, an operation mode and the like of the present embodiment having such a configuration will be described. That is, the vibration from the vibrating body side is transmitted to the insulator 2 made of a rubber material or the like via the upper connecting member 6 as shown in FIG. Along with this, the insulator 2 vibrates or deforms to absorb or block most of the input vibration. Therefore, most of the vibrations are cut off at the insulator 2, but some of the vibrations are not cut off at the insulator 2 but cut off at the next vibration isolation mechanism 1. Become. Next, a specific operation of the vibration isolation mechanism 1 will be described. First, with respect to idling vibration, the switching means 3 is operated so that negative pressure or atmospheric pressure is alternately introduced into the equilibrium chamber 13 at a specific frequency. That is, by operating the switching means 3 at a specific frequency, the pressure (volume) in the equilibrium chamber 13 is changed, whereby the main chamber caused by idling vibration inputted through the insulator 2 is changed. Fluctuations in the hydraulic pressure in 12 are absorbed. As a result, the dynamic spring constant of the spring system formed by the insulator 2 and the main vibration isolator 1 is reduced.
[0015]
In particular, in this case, in the present embodiment, a mass 111 having a predetermined mass is provided at the diaphragm 11 which is provided in the main chamber 12 and forms the equilibrium chamber 13. Therefore, the mass 111 resonates in response to a change in volume (operation) in synchronization with the idling vibration of the equilibrium chamber 13. That is, a resonance system for idling vibration is formed by a spring composed of the mass 111 having a predetermined mass and the elastic diaphragm 115 provided around the mass 111. Accordingly, the generated force (vibration energy) in the vibration isolating mechanism 1 for idling vibration has a large value, and only the generated energy at the natural frequency (fn) related to the idling vibration to be processed is: It comes to have a sharp peak value. In other frequency ranges, the generated energy is relatively reduced. As a result, noise and the like, which are vibrations of high frequency components, in the practically generated energy region are extremely reduced. Therefore, it is possible to avoid the occurrence of high-frequency vibration associated with the interruption of idling vibration, which has been a concern in the related art.
[0016]
Further, with respect to the engine shake which is a vibration of a lower frequency than the idling vibration, the liquid is caused to flow in the orifice 15 connecting the main chamber 12 and the sub-chamber 16, thereby The engine shake is absorbed and cut off. That is, in the present embodiment, as shown in FIG. 1, a constant negative pressure is continuously introduced into the equilibrium chamber 13 forming the vibration isolation mechanism 1 to form the equilibrium chamber 13. The diaphragm 11 with the mass to be drawn is pulled down, and the volume of the equilibrium chamber 13 is set to zero. This prevents the volume of the equilibrium chamber 13 from changing. In such a state, when the vibration from the vibrating body is propagated to the insulator 2, the lower surface of the insulator 2 vibrates in response to the vibration, and the liquid in the main chamber 12 is actively subsided. It operates to flow to the chamber 16 side. As a result, the liquid in the main chamber 12 flows to the sub-chamber 16 through the orifice 15. A predetermined damping force is generated by viscous resistance caused by the flow of the liquid, and the engine shake is suppressed (attenuated) by the damping force.
[0017]
On the other hand, with respect to a high frequency vibration of about 100 Hz to 600 Hz which causes a muffled sound which is a problem during running of the vehicle, the switching means 3 is operated to bring the equilibrium chamber 13 into a state of being opened to the atmosphere. I do. As a result, atmospheric pressure is introduced into the equilibrium chamber 13, and the second diaphragm 11 forming the equilibrium chamber 13 operates (vibrates) freely. As a result, the liquid in the main chamber 12 relatively freely flows in the main chamber 12 with respect to the vibration input from the insulator 2 side. As a result, the dynamic spring constant of the spring system formed by the entire vibration isolator can be kept low. Therefore, the effect of blocking vibration in a high frequency range is enhanced.
[0018]
【The invention's effect】
According to the present invention, by adopting the above configuration, for various vibration inputs, the hydraulic pressure fluctuation in the main chamber is controlled, and finally, the dynamic spring constant of the present liquid-filled type vibration damping device is reduced, Further, high damping characteristics in a low frequency range can be formed, and various vibrations such as idling vibration can be cut off.
[0019]
Furthermore, only the generated energy at the natural frequency (fn) relating to the idling vibration of interest has a sharp peak value, while the generated energy is relatively small in other frequency ranges. This makes it possible to prevent the occurrence of high-frequency vibrations associated with the blocking of idling vibration, which has been a concern in the prior art.
[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 the overall configuration of a general automatic control mount device (ACM).
[Explanation of symbols]
1 Anti-vibration mechanism 11 Diaphragm (diaphragm with mass)
111 Mass 115 Elastic diaphragm (elastic diaphragm)
REFERENCE SIGNS LIST 12 Main chamber 13 Balancing chamber 14 Partition plate 15 Orifice 16 Sub-chamber 17 Diaphragm 18 Air chamber 2 Insulator 3 Switching means 31 Switching valve 32 Solenoid 35 Throttle valve 5 Control means 6 Upper connecting member 9 Lower connecting member

Claims (1)

An upper connecting member attached to the vibrating body, a lower connecting member attached to the vehicle body , an insulator between the upper connecting member and the lower connecting member for absorbing and blocking vibration from the vibrating body, and an insulator for the insulator. A main chamber in which a liquid as an incompressible fluid is sealed, a sub-chamber connected to the main chamber via an orifice so that the liquid flows, and An anti-vibration mechanism formed in the chamber through a diaphragm and provided with an equilibrium chamber formed to introduce one of atmospheric pressure and negative pressure; and and switching means for switching operates to introduce either one of the one of the balancing chamber to the negative pressure or atmospheric pressure of the mechanism, by controlling the switching operation of said switching means, negatively the equilibrium chamber And a state of continuously introducing one of the atmospheric pressure, from a control means for switching to the state to be alternately introduced in a state of being synchronized with negative pressure and the atmospheric pressure to the vibration of the vibrator to the equilibrium chamber In the liquid-filled type vibration damping device, the diaphragm forming the equilibrium chamber is configured so that a peripheral portion thereof is formed of an elastic diaphragm formed of a rubber-like member, and a central portion of the diaphragm is formed in the rubber-like elastic member. A liquid-filled type vibration damping device having a configuration having a mass of a predetermined mass.

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