JP2004324822A - Liquid-sealing vibration-resistant device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily control inner pressure absorbing performance by preparing an inner pressure adjusting means in a liquid-sealing vibration-resistant device. <P>SOLUTION: A small assembled body 1 for an engine mount is provided with a first mounting member 2, a second mounting member 3 and an insulator 4, and is integrated with a bracket 5 by press-fitting it into the bracket 5. A hole oriffice 13 is arranged on a partition member 7, and an inner pressure absorbing membrane 27 is arranged on a side wall surrounding a primary fluid chamber 6. An adjusting chamber 28 surrounded by a second diaphragm 29 is arranged on a side opposite to the primary fluid chamber 6 of the inner pressure absorbing membrane 27, and magnetic viscous fluid 30 enclosed in the adjusting chamber 28 is changed at a coefficient of viscosity by means of magnetic force of a coil 32. Thus, an inner pressure adjusting means 37 is organized by these objects, mobility of the inner pressure absorbing membrane 27 is controlled while the coil 32 is changed at magnetic force, and inner pressure absorbing ability is also changed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ring vibration isolator, and more particularly, to a device capable of easily controlling an internal pressure.
[0002]
[Prior art]
A first mounting member mounted on the vibration source side, a second mounting member mounted on the vibration receiving side, an insulator interposed therebetween for absorbing vibration, and a liquid in which the insulator forms part of a wall. The liquid chamber is divided into a main liquid chamber and a sub liquid chamber and communicated with each other through an orifice passage, and an internal pressure absorbing film is provided in a part of a wall surrounding the main liquid chamber to reduce the film rigidity. 2. Description of the Related Art An internal pressure absorption type liquid-tight engine mount that is switched between rigid and soft is known. In this type of engine mount, if the internal pressure absorbing film is softened, the internal pressure change is absorbed and a low dynamic spring is obtained, and if the internal pressure absorbing film is made rigid, the expansion spring, which is a spring generated by the internal pressure change in the engine mount, is raised. The flow rate to the orifice passage is increased, thereby increasing resonance efficiency and reducing vibration transmission.
[0003]
Such a film stiffness varying means, for example, provides a negative pressure chamber on the opposite side of the main pressure chamber of the internal pressure absorbing film, and switches the connection of the negative pressure chamber to a negative pressure source or the atmosphere, thereby forming the internal pressure absorbing film. It becomes stiff when adsorbed and fixed to a wall or the like with negative pressure, and becomes soft when released to the atmosphere and put into a free state. It is also known to forcibly elastically deform the internal pressure absorbing film by mechanical means such as a motor (see Patent Documents 1 and 2). Further, there is a type in which the periphery of an elastic film provided between the main liquid chamber and the sub liquid chamber is supported by a supporting member, and the supporting force of the supporting member is changed by a change in the viscosity of the magnetic viscous fluid (Patent Document 1). 3).
[0004]
[Patent Document 1] JP-A-10-325443
[Patent Document 2] JP-A-2003-4090
[Patent Document 3] JP-A-2002-213517
[0005]
[Problems to be solved by the invention]
By the way, an apparatus utilizing an intake negative pressure as a driving means of the internal pressure absorbing film requires piping of an air passage and a switching valve, so that the entire apparatus is relatively complicated and the weight increases. The same applies when mechanical means such as a solenoid is used. Furthermore, if stepless and continuous control is to be performed, it is difficult to perform control based on intake negative pressure, and it is due to mechanical means such as a solenoid. In this case, a device that operates with high precision is required. .
Therefore, an object of the present invention is to enable internal pressure control with a relatively simple and lightweight structure.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the liquid sealing vibration isolator according to the present invention is characterized in that a first mounting member mounted on the vibration source side, a second mounting member mounted on the vibration receiving side, and A liquid seal vibration isolator comprising an insulator interposed to absorb vibration and a liquid chamber in which the insulator forms a part of a wall, and the liquid chamber is divided into a main liquid chamber and a sub liquid chamber connected by a resonance orifice. At
Providing an internal pressure adjusting means for the main liquid chamber, while adjusting the internal pressure absorbing capacity by this internal pressure adjusting means,
The internal pressure adjusting means includes: a first movable portion deformed or displaced by receiving the hydraulic pressure of the working fluid; an adjustment chamber in which at least a part of the wall portion is formed by the first movable portion; Provided, a magnetic viscous fluid, a second movable portion that is deformed or displaced to suppress a change in volume of the adjustment chamber, and a coil that generates a magnetic force to change the viscosity of the magnetic viscous fluid,
A liquid-sealing anti-vibration method, wherein the viscosity of the magnetic viscous fluid is changed by a change in magnetic force to change the amount of deformation or displacement of the first movable portion, thereby controlling the internal pressure absorbing ability of the internal pressure adjusting means. apparatus.
[0007]
A second aspect of the present invention is characterized in that, in the first aspect, the internal pressure absorbing ability is changed continuously or in multiple steps by changing the viscosity of the magnetic viscous fluid continuously or in multiple steps.
[0008]
According to a third aspect, in the first aspect, a flow resistance unit for the magnetic viscous fluid is provided in the adjustment chamber.
[0009]
According to a fourth aspect of the present invention, in the first aspect, the first movable portion is an internal pressure absorbing film made of an elastic film that elastically deforms to absorb a change in internal pressure, and the second movable portion is a diaphragm, and at least a part of the diaphragm is an atmosphere. It is characterized by being open.
[0010]
According to a fifth aspect of the present invention, in the first aspect, the resonance orifice is a damping orifice.
[0011]
According to a sixth aspect of the present invention, in the first aspect, the resonance orifice includes first and second orifices whose resonance frequencies are relatively different in height from each other, and the second orifice having a higher resonance frequency is an open / close type. Features.
[0012]
According to a seventh aspect of the present invention, there is provided the hole orifice according to the first aspect, wherein the hole orifice communicates with the main liquid chamber with a predetermined opening diameter and generates a liquid column resonance at a predetermined frequency by surrounding the opening with an elastic film. Is provided.
[0013]
【The invention's effect】
According to the first aspect, as the internal pressure adjusting means, a first movable part, a second movable part forming an adjustment chamber between the first movable part, a magnetic viscous fluid sealed in the adjustment chamber, And a coil for generating a magnetic force that changes the viscosity of the magnetic viscous fluid, so that when the first movable unit attempts to displace or deform, the volume change of the adjustment chamber accompanying the displacement or deformation of the second movable unit Displacement and deformation of the first movable portion are allowed while displacement is suppressed. Further, when the magnetic force by the coil is changed, the viscosity of the magnetic viscous fluid changes, and the ease of movement of the first movable portion changes. As a result, the amount of elastic deformation of the first movable portion with respect to the change in the internal pressure changes, and the ability to absorb the internal pressure, that is, the internal pressure absorbing ability changes. Therefore, according to this internal pressure adjusting means, the internal pressure can be freely adjusted only by changing the magnetic force. In addition, since the control can be performed only by adjusting the magnetic force, the control can be performed quickly and easily.
[0014]
According to the second aspect, since the viscosity of the magnetic viscous fluid is changed continuously or in multiple steps, the internal pressure absorbing capacity is changed continuously or in multiple steps to change the internal pressure absorbing capacity continuously or in multiple steps. Can be. In addition, such control merely changes the magnetic force, so that the internal pressure can be freely adjusted stepwise, or even steplessly and continuously. In addition, since the control can be performed only by adjusting the magnetic force, it can be easily controlled.
[0015]
According to the third aspect, since the flow resistance means of the magnetic viscous fluid is provided in the adjustment chamber, the change in the film rigidity can be amplified with respect to the change in the viscosity.
[0016]
According to the fourth aspect, the first movable portion is an internal pressure absorbing film made of an elastic film that elastically deforms and absorbs a change in internal pressure, the second movable portion is a diaphragm, and at least a part of the diaphragm is opened to the atmosphere. Thereby, the elastic film serving as the first movable portion can be deformed, and a change in volume of the adjustment chamber accompanying the deformation can be suppressed. In addition, by forming the first movable portion and the second movable portion as film members, these can be easily formed.
[0017]
According to the fifth aspect, when applied to a liquid ring vibration isolator in which the resonance orifice is a damping orifice, the internal pressure adjusting means lowers the internal pressure absorbing ability in the resonance frequency range of the damping orifice, thereby increasing the resonance efficiency of the damping orifice. Thus, high damping can be achieved with respect to vibrations in the riding comfort area, and in other areas, a low dynamic spring can be realized by increasing the internal pressure absorbing capacity. Moreover, such control can be easily realized by the internal pressure adjusting means utilizing the viscosity change of the magnetic viscous fluid. In particular, the present invention is effective in a liquid ring vibration isolator having no resonance control means other than the damping orifice.
[0018]
According to the sixth aspect, when the resonance orifice is provided with the first and second orifices having different resonance frequencies, and the second orifice having a high resonance frequency is opened and closed, the second orifice can be opened and closed. The internal pressure can be adjusted in connection with opening and closing. In other words, in the resonance frequency range of the second orifice, when the second orifice is opened, the internal pressure absorbing ability is reduced and the resonance efficiency of the second orifice is increased, thereby achieving high phase and low dynamic spring (appearing as a minimum value of the dynamic spring curve). The bottom of the second orifice can be lowered in other areas, and even when the second orifice is closed in other areas, the dynamic spring can be reduced by absorbing the internal pressure. Also in this case, in a region where the resonance of the first orifice is required, the internal pressure adjusting means can reduce the internal pressure absorbing ability and increase the resonance efficiency of the first orifice. Moreover, such control can be easily realized by the internal pressure adjusting means utilizing the viscosity change of the magnetic viscous fluid.
[0019]
According to the seventh aspect, since the hole orifice is provided, the resonance frequency and the phase of the hole orifice can be changed by adjusting the internal pressure absorbing ability. As a result, the resonance frequency and phase of the liquid column resonance generated in the hole orifice change continuously or in multiple stages, and the resonance frequency and phase can be controlled in a wide range. In particular, by controlling the phase over a wide range, the vibration of the vector component can be absorbed and the transmission of the vibration can be reduced. Moreover, such control can be easily realized by the internal pressure adjusting means utilizing the viscosity change of the magnetic viscous fluid.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments will be described with reference to the drawings. 1 to 4 relate to the first embodiment, FIG. 1 is an overall sectional view of a liquid ring vibration isolator, FIG. 2 is an enlarged sectional view of an essential part for explaining an operation principle, and FIG. FIG. 4 is a diagram showing a change in a point, and FIG. 4 is a diagram showing a change in a phase accompanying a change in an extension spring.
[0021]
In FIG. 1, the engine mount subassembly 1 includes a first mounting member 2, a second mounting member 3, and an insulator 4. The first mounting member 2 is connected to a vibration source side such as an engine (not shown), the second mounting member 3 is fitted to a bracket 5, and the bracket 5 is also connected to a vibration receiving side such as a vehicle body (not shown). The insulator 4 is a known anti-vibration rubber having a substantially conical shape made of rubber. However, a known elastic vibration isolating member having a substantially conical shape made of an appropriate elastic material such as rubber and other elastomers can be used, and a vibration isolating member between the first mounting member 2 and the second mounting member 3 can be provided. Connect to
[0022]
A main liquid chamber 6 is formed inside the first mounting member 2, the second mounting member 3, the insulator 4 and the partition member 7, and a well-known incompressible hydraulic fluid is sealed therein. The main liquid chamber 6 communicates with the sub liquid chamber 9 via a damping orifice 8 formed on the outer periphery of the partition member 7. The damping orifice 8 can provide a high damping to vibrations during normal running which affect the riding comfort of low frequency and small amplitude of about 10 Hz. The sub liquid chamber 9 is covered by the first diaphragm 10.
[0023]
The partition member 7 is a disk-shaped member made of a suitable material such as a resin, and has an opening 11 formed at the center thereof, and an elastic film 12 is attached thereto. The opening 11 and the elastic film 12 form a hole orifice 13 which resonates with a liquid column at a predetermined frequency (about 60 Hz in this embodiment) by liquid vibration in the main liquid chamber 6. This resonance frequency range is a vibration frequency range at the time of starting. The hole orifice is a type of resonance in which one end side of the orifice passage is covered with an elastic film to generate a liquid flow in the orifice passage by the liquid vibration of the main liquid chamber 6 and the vibration of the elastic film, thereby causing liquid column resonance. Orifice.
[0024]
The damping orifice 8 is formed on the outer periphery of the partition member 7 so as to open radially outward, and communicates with the main liquid chamber 6 at an inlet 14a formed at a part thereof and communicates with the sub-liquid chamber 9 at an outlet 14b. I do. Further, the opening of the damping orifice 8 which is opened radially outward to the outer periphery of the partition member 7 is tightly sealed with a cylindrical elastic wall 15 which is continuous with the outer periphery of the first diaphragm 10. The cylindrical elastic wall 15 is made of an appropriate elastic member made of rubber or the like similar to the insulator 4 and covers the inner peripheral surface and the outer peripheral surface of the second mounting member 3.
[0025]
The second mounting member 3 is a cylindrical member made of metal or the like, and includes a small-diameter portion 16 surrounding the outer peripheral side of the damping orifice 8 and a large-diameter portion 17 surrounding the main liquid chamber 6. A flange 18 is formed and overlaps the upper end of the bracket 5. Further, a ring fitting 19 integrated with a lower portion of the insulator 4 overlaps the flange 18, and the insulator 4, the second mounting member 3, and the bracket 5 are combined and integrated by an appropriate method such as a rivet. The lower end of the small diameter portion 16 forms a bottom portion 20 and is placed and positioned on a step 21 formed on the inner surface of the bracket 5.
[0026]
The partition member 7 is inserted into the inside of the cylindrical elastic wall 15, and the lower part of the outer periphery is placed on the step part 22 formed by the bottom part 20 and positioned. In this state, the engine mount subassembly 1 is configured by integrating the flange 18 at the upper end of the second mounting member 3 and the ring fitting 19 of the insulator 4 by bending or caulking (not shown). The engine mount is assembled by inserting the engine mount subassembly 1 into the bracket 5 and integrating the flange 18 with the upper end of the bracket 5 by appropriate means such as rivets.
[0027]
An annular wall 23 protruding upward in the drawing is integrally formed on the outer peripheral portion of the partition member 7, and the working fluid is filled between the annular wall 23 and the cylindrical elastic wall 15 covering the large diameter portion 17. An annular chamber 24 is formed. The annular wall 23 has a cutout 25 at a part in the circumferential direction, where the annular chamber 24 communicates with the main liquid chamber 6.
[0028]
Further, an opening 26 is formed at a portion corresponding to the cutout portion 25 of the large diameter portion 17, and the opening 26 portion of the cylindrical elastic wall 15 is an internal pressure absorbing film 27. The internal pressure absorbing film 27 is an elastic film made of an appropriate elastic material such as rubber, which is continuous and integral with the cylindrical elastic wall 15, and absorbs the internal pressure fluctuation of the main liquid chamber 6 by elastic deformation. In addition, it can also be formed separately from the cylindrical elastic wall 15.
[0029]
As shown in FIG. 2, an adjustment chamber 28 is formed on a side of the internal pressure absorbing film 27 opposite to the main liquid chamber 6 so as to be surrounded by a second diaphragm 29. A well-known magnetic viscous fluid 30 is sealed inside the adjustment chamber 28. At least a part of the second diaphragm 29 on the side opposite to the adjustment chamber 28 is open to the atmosphere, and the outer peripheral portion is integrated with a fixed ring 31. A coil 32 is attached to the fixed ring 31. The outer peripheral portion of the fixing ring 31 is overlaid on the outer surface of the bracket 5 and is integrally attached by a suitable means such as a rivet.
[0030]
The coil 32 surrounds the adjustment chamber 28, and generates a magnetic force so that the viscosity of the magnetic viscous fluid 30 can be instantaneously changed from a water-like state to a sherbet state. The magnetic force generated by the coil 32 is generated continuously or in multiple stages by a control device (not shown) based on an appropriate sensor amount such as the number of revolutions of the engine. The viscosity of the magnetic viscous fluid 30 also changes. In this embodiment, the viscosity is set so as to change in three stages of high, medium and low. This setting will be described later.
[0031]
When the viscosity of the magnetic viscous fluid 30 increases, the internal pressure absorbing film 27 is less likely to be elastically deformed, so that the internal pressure absorbing ability is reduced, and the expansion spring, which is a spring generated by a change in internal pressure as a vibration isolator, is increased. The resonance frequency of the orifice 13 is increased.
Conversely, when the viscosity is reduced, the internal pressure absorbing film 27 is easily elastically deformed and the internal pressure absorbing ability is increased, so that the expansion spring is reduced and the resonance frequency of the hole orifice 13 is reduced.
[0032]
A resistance plate 33 is provided in the adjustment chamber 28, an outer peripheral portion 34 of the resistance plate 33 is integrated with the coil 32, and a throttle passage 35 is formed in the center. When the magnetic viscous fluid 30 passes through the throttle passage 35, Damping force is generated by viscosity resistance. The opening diameter of the throttle passage 35 can be set arbitrarily within a range in which the magnetic viscous fluid 30 can generate a damping force. The throttle passage 35 can be formed by providing a plurality of relatively small holes.
[0033]
The outer peripheral portion 34 of the resistance plate 33 and the coil 32 are fitted and fixed in mounting holes 36 formed in the side wall of the bracket 5. The metal fitting overlapping the inner peripheral surface side of the coil 32 is a fixing ring 31, and the outer peripheral part of the second diaphragm 29 is integrated by baking or the like. The outer peripheral portion of the fixing ring 31 overlaps the outer surface of the coil 32. Fixed ring 31 and outer peripheral portion 34
Is sealed by an appropriate means.
[0034]
In addition, the portion of the surface of the fixing ring 31 that is covered by a portion of the second diaphragm 29 is reduced, and most of the portion directly faces the adjustment chamber 28, thereby preventing loss of magnetic force. The internal pressure absorbing film 27, the adjusting chamber 28, the second diaphragm 29, the magnetic viscous fluid 30, and the coil 32 are collectively referred to as an internal pressure adjusting unit 37. Further, the positional relationship between the main pressure chamber 6 and the internal pressure absorbing film 27 constituting the internal pressure adjusting means 37 and the second diaphragm 29 may be reversed.
[0035]
Next, a method of setting the film rigidity of the internal pressure absorbing film 27 will be described. FIG. 3 is a diagram showing a change in the resonance point of the hole orifice 13 in the three-stage expansion spring. The horizontal axis represents the frequency, the vertical axis represents the dynamic spring, and the minimum point of each curve is the resonance point. As is apparent from this figure, when the expansion spring changes from small-medium-large, the respective resonance points become low-medium-high.
[0036]
This expansion spring can be realized by changing the internal pressure absorbing ability of the internal pressure adjusting means 37, and the internal pressure absorbing ability is determined by the degree of easiness of movement of the internal pressure absorbing film 27. Further, the ease of movement of the internal pressure absorbing film 27 is determined by the fluidity of the magnetic viscous fluid sealed in the adjustment chamber. Here, if the index of the fluidity in the viscosity flow is expressed by the flow resistance, if the flow resistance is large, the internal pressure absorbing film 27 becomes difficult to move and the expansion spring becomes large. On the other hand, if the flow resistance is small, the internal pressure absorbing film 27 becomes easy to move, and the expansion spring becomes small.
[0037]
Further, the magnitude of the flow resistance is determined by the viscosity of the magnetic viscous fluid if the throttle passage 35 of the resistance plate 33 is constant. Therefore, if the strength of the magnetic force generated by the coil 32 is adjusted to change the viscosity of the magnetic viscous fluid, the flow resistance changes and the easiness of movement of the internal pressure absorbing film 27 changes. Noh will change. As a result, a corresponding change in the expansion spring is obtained.
[0038]
Therefore, if the magnetic force of the coil 32 is changed, it is possible to freely change the internal pressure absorbing ability and obtain an arbitrary expansion spring. Therefore, the internal pressure adjusting means 37 in the present embodiment changes the magnetic force into three stages of 0 and small and large so that the expansion spring can be controlled in three stages of small-medium-large. In addition, the size of the expansion spring can be controlled in multiple steps or continuously without step by changing the magnetic force.
[0039]
For example, if the magnetic force that realizes the internal pressure absorption ability that gives the expansion spring that realizes the resonance point of the maximum frequency at the time of starting is maximized, the magnetic force is made smaller in the expansion spring, and smaller than the expansion spring. By setting the magnetic force to 0, the magnetic force can be switched between three levels to change the resonance point from low to medium to high.
[0040]
Next, the operation of the present embodiment will be described. At the time of starting, the coil 32 of the internal pressure adjusting means 37 is not energized, the magnetic force is initially set to 0, and the hole orifice 13 generates liquid column resonance at a relatively low frequency to absorb input vibration. Thereafter, the frequency of the input vibration to the main liquid chamber 6 increases as the engine speed increases, and the current is increased by energizing the coil 32 in accordance with the increase in the frequency. The viscosity is increased and the internal pressure absorbing capacity of the internal pressure adjusting means 37 is switched between medium and small and controlled.
[0041]
Thus, the extension spring is switched and controlled to change the resonance point stepwise to middle or high. As a result, the expansion spring is controlled to be switched in three stages in a relatively wide frequency range from low to high, and the resonance point of the hole orifice 13 is changed in three stages in accordance with the switching, thereby making the resonance region wide. At this time, since the resistance plate 33 is provided, the damping force generated when the magnetic viscous fluid 30 passes through the throttle passage 35 is obtained by amplifying the viscosity change. As a result, the change in the internal pressure absorption capacity can be increased, and the change in the internal pressure absorption capacity can be made higher than in the case where the internal pressure absorption capacity is formed only by the viscosity change of the magnetic viscous fluid.
[0042]
In addition, the phase changes according to the change of the resonance point. FIG. 4 is a diagram showing this phase change, in which the horizontal axis shows the frequency and the vertical axis shows the phase, and each curve is a phase curve corresponding to three stages of large-medium-small of the extension spring. This is the maximum phase generated by each expansion spring. As is apparent from this figure, as the resonance frequency increases, the maximum phase also increases almost linearly as indicated by a broken line. The predicted maximum phase of this embodiment changes from small-medium-large in response to the expansion spring changing from small-medium-large.
[0043]
As a result, a relatively large phase can be generated in a wide frequency range (low to high), and vibrations requiring phase control, for example, body vibrations can be suppressed. Moreover, such a wide resonance area and the generation of a relatively large phase can be realized with only one hole orifice 13, and there is no need to provide a plurality of orifices corresponding to each resonance point, so that the structure is simplified. . In addition, if the control is performed according to the engine speed, the resonance frequency and phase can be accurately changed according to the operating condition of the engine.
[0044]
In addition, the internal pressure absorbing ability of the internal pressure adjusting means 37 can be directly controlled by a change in the viscosity of the magnetic viscous fluid 30 in the adjusting chamber 28 in which the internal pressure absorbing film 27 forms a part of the wall. Since the viscosity of the fluid 30 can be quickly and easily controlled, the control of the internal pressure absorption capacity is quick, easy, and accurate. Further, since no mechanical means such as a solenoid or a motor is required, the structure of the internal pressure adjusting means 37 is relatively simple.
[0045]
Next, a second embodiment will be described. Note that the same reference numerals are used for parts common to the previous embodiment, and in principle, redundant description of the common parts will be omitted. FIG. 5 is an overall sectional view of the liquid-sealed vibration isolator according to the second embodiment.
[0046]
As shown in FIG. 5, in the engine mount of this embodiment, the partition member 7 has an up-and-down structure of upper and lower members 7a and 7b, and an idle orifice 40 is provided in the interior thereof instead of the hole orifice. . The idle orifice 40 communicates with the main liquid chamber 6 and the sub liquid chamber 9 to generate a liquid column resonance at an engine vibration frequency during idling (about 20 Hz) to reduce the dynamic movement of the first mounting member 2. Vibration transmission from the side to the second mounting member 3 side is reduced.
[0047]
The outlet 41 of the idle orifice 40 on the side of the auxiliary liquid chamber 9 is openable and closable by an opening / closing valve 43 formed at the center of the first diaphragm 10, and is open only in an idle frequency range, and is closed in other cases. The opening and closing valve 43 is opened and closed by the expansion and contraction of the pressing member 44. The first diaphragm 10 covers the sub liquid chamber 9, but differs in that an opening / closing valve 43 is integrated at the center.
[0048]
A negative pressure chamber 46 is formed between the pressing member 44 and the bottom 45, and the connection between the intake negative pressure and the atmosphere is switched via a ventilation nozzle 47. When the intake negative pressure is applied, the valve moves downward in the figure against the return spring 48, and the opening / closing valve 43 opens the outlet 41. When the intake negative pressure is shut off and the atmosphere is released, the return spring 48 And exit 41 is closed.
[0049]
In the present embodiment, a pair of opposed internal pressure adjusting means 37 is provided. The structure of each internal pressure adjusting means 37 is the same as in the previous embodiment. Each of the internal pressure absorbing films 27 faces an annular chamber 24 formed between the annular wall 23 formed by the upper member 7 a constituting the partition member 7 and the inner wall surface of the main liquid chamber 6, and faces the annular wall 23. I have.
[0050]
Next, the operation of the present embodiment will be described. During idling, the open / close valve 43 is opened and the idle orifice 40 connects the main liquid chamber 6 and the sub liquid chamber 9. At the same time, each coil 32 in each internal pressure adjusting means 37 is energized to make each internal pressure absorbing film 27 most difficult to move. Therefore, the flow rate of the liquid to the idle orifice 40 increases, and the resonance efficiency increases. In general, the idle speed changes depending on whether the headlights are turned on or the air conditioner is turned on / off. In this case, the internal pressure absorbing ability can be controlled according to the idle speed.
[0051]
Conversely, when the engine is not idling, the opening / closing valve 43 is closed, and at the same time, the energization of each coil 32 in each internal pressure adjusting means 37 is stopped to make each internal pressure absorbing film 27 most movable, thereby maximizing the internal pressure absorbing capacity. For this reason, each internal pressure absorbing film 27 is in a soft state, and the internal pressure fluctuation of the main liquid chamber 6 is absorbed by elastic deformation to make a low dynamic spring. In addition, even when the opening / closing valve 43 is closed, at the time of shake vibration, the internal pressure absorbing ability is reduced by operating each internal pressure adjusting means 37 based on a signal from an appropriate sensor for detecting, for example, engine deviation. Let it. For this reason, each internal pressure absorbing film 27 is in a rigid state, and the expansion spring is raised, so that the resonance efficiency of the damping orifice 8 is increased, and high damping is realized, so that shake vibration can be effectively reduced.
[0052]
When a plurality of internal pressure adjusting means 37 are provided in this manner, if a single internal pressure adjusting means 37 becomes too large to obtain a certain level of performance, a plurality of relatively small internal pressure adjusting means 37 may be used. Thereby, required performance can be easily realized. Also, providing a plurality of small internal pressure adjusting means 37 provides better strength balance than providing only one.
[0053]
Next, a third embodiment will be described. FIG. 6 is an overall sectional view of the liquid-sealed vibration isolator according to the third embodiment. As shown in FIG. 6, the engine mount of this embodiment is different from the engine mount of FIG. 5 in that a hole orifice 13 is provided. That is, a passage 50 is provided on the side of the partition member 7, and the entrance 51 facing the main liquid chamber 6 formed at the upper end thereof is made openable and closable by a valve 52. The valve 52 is driven in a radial direction by a driving means 53 such as a motor. And the entrance 51 is opened and closed.
[0054]
An elastic film 12 is attached to a lower end 54 of the passage 50 facing the sub liquid chamber 9, and the elastic film 12 and the passage 50 constitute a hole orifice 13. When the liquid in the main liquid chamber 6 flows by input vibration with the valve 52 opened, the hole orifice 13 generates liquid column resonance at a predetermined input frequency. This resonance frequency is set to be about 60 Hz when each internal pressure absorbing film 27 is in the softest state.
[0055]
For this reason, until the idle frequency, the hole orifice 13 is closed, control is performed in the same manner as in the previous embodiment, and after starting, the valves 52 are opened with the internal pressure absorbing films 27 in the softest state. Thus, when the input vibration becomes about 60 Hz, the hole orifice 13 resonates with the liquid column and absorbs the input vibration. Thereafter, when the frequency of the input vibration further increases, the plurality of internal pressure adjusting means 37 are controlled as in the previous embodiment, and the resonance frequency and phase are controlled using the hole orifice 13 as in the first embodiment.
[0056]
In this way, vibration can be efficiently prevented in the widest frequency range using the damping orifice 8, the idle orifice 40, the hole orifice 13, and the plurality of internal pressure adjusting means 37.
[0057]
Next, a fourth embodiment will be described. FIG. 7 is an overall sectional view of a liquid-sealed vibration isolator according to the fourth embodiment, and corresponds to FIG. FIG. 8 is an enlarged cross-sectional view of a part of FIG. This embodiment corresponds to a modification of the structure and arrangement of the internal pressure adjusting means in FIGS. Hereinafter, only the differences will be described. Note that the same portions are denoted by the same reference numerals and description thereof will be omitted.
[0058]
As shown in FIGS. 7 and 8, the internal pressure adjusting means 37 is arranged to be accommodated inside the bracket 5. The second diaphragm 29 is formed as a part of the tubular elastic wall 15 so as to cover the opening 26 provided in the large-diameter portion 17 embedded inside the elastic wall 15. On the other hand, the internal pressure absorbing film 27 is formed separately from the cylindrical elastic wall 15 and is fitted into the cutout 25 of the annular wall 23.
[0059]
A frame fitting 60 is integrated around the inner pressure absorbing film 27. The frame fitting 60 has a substantially U-shaped cross section, has an opening 60 a formed in the center thereof for elastic deformation of the internal pressure absorbing film 27, and the outer peripheral portion overlaps the outer peripheral portion of the coil 32. An outer peripheral portion 34 of the resistance plate 33 is fixedly abutted on an inner peripheral portion of the coil 32. Part of the inner peripheral side of the coil 32 directly faces the adjustment chamber 28 to prevent loss of magnetic force.
[0060]
When assembled in this state, the periphery of the internal pressure absorbing film 27 includes a lower portion 61 of the insulator 4, a portion of the annular wall 23 surrounding the cutout portion 25, and a step 62 formed at a lower portion of the cylindrical elastic wall 15. Sealed with. Reference numeral 63 indicates this sealing surface. Further, the end face of the outer peripheral portion facing the cylindrical elastic wall 15 is sealed by contacting the cylindrical elastic wall 15 together with the coil 32. Therefore, the magnetic viscous fluid 30 can be reliably and easily sealed.
[0061]
In addition, since the adjustment chamber 28 is provided inside the cylindrical elastic wall 15 and is formed so as to open toward the inside of the main liquid chamber 6, the sealing surface 63 is closer to the main liquid chamber 6 than the cylindrical elastic wall 15. Provided. Therefore, even if the magnetic viscous fluid 30 leaks from the sealing surface 63 due to a decrease in sealing performance, the magnetic viscous fluid 30 leaks into the main liquid chamber 6 and does not leak to the outside. Therefore, even if the seal for the magnetic viscous fluid 60, which is difficult to seal, is broken, the internal magnetic viscous fluid 30 can be prevented from flowing out.
[0062]
Next, a fifth embodiment will be described. FIG. 9 corresponds to the one in which the hole orifice 13 (FIG. 1) is omitted from the partition member 7 in the first embodiment of FIG. 1, and the internal pressure adjusting means 37 is connected to the liquid-tight engine mount having only the damping orifice 8 as the resonance orifice. This is an example in which is provided. Even in an engine mount (non-control type mount) having no resonance orifice controlled in this way, the internal pressure absorbing capability of the internal pressure adjusting means 37 is reduced in the vibration region where the damping orifice works, and the internal pressure absorbing capability is reduced in other regions. By raising and adjusting the degree, the dynamic spring can be reduced. Therefore, even in such a non-control type mount, the internal pressure can be easily controlled using magnetic force as in the previous embodiments.
[0063]
The present invention is not limited to the above embodiments, but can be variously modified. For example, the number of stages of adjusting the film rigidity of the internal pressure absorbing film 27 can be increased. Further, it can be continuously changed steplessly. Further, the present invention can be applied to various other vibration isolators other than the engine mount.
Further, the internal pressure adjusting means of the fourth embodiment shown in FIGS. 7 and 8 can be freely applied to each embodiment of FIGS. 1 to 6 and 9.
Further, the internal pressure absorbing film 27 and the second diaphragm 29 do not necessarily need to be film-like members, but may be members such as a movable plate that slides and displaces in the adjustment chamber. Further, one of the members may be a film member, and the other may be a combination of a non-film member such as a movable plate.
[Brief description of the drawings]
FIG. 1 is an overall sectional view of a liquid ring vibration isolator according to a first embodiment.
FIG. 2 is an enlarged sectional view of a main part showing an operation principle.
FIG. 3 is a diagram showing a change in a resonance point due to a change in an extension spring.
FIG. 4 is a diagram showing a change in phase due to a change in an extension spring.
FIG. 5 is an overall sectional view of a liquid-sealed vibration isolator according to a second embodiment.
FIG. 6 is an overall cross-sectional view of a liquid ring vibration isolator according to a third embodiment.
FIG. 7 is an overall sectional view of a liquid ring vibration isolator according to a fourth embodiment.
FIG. 8 is an enlarged cross-sectional view of a part of FIG. 7;
FIG. 9 is an overall sectional view of a liquid ring vibration isolator according to a fifth embodiment.
[Explanation of symbols]
1: engine mount subassembly, 2: first mounting member, 3: second mounting member, 4: insulator, 5: bracket, 6: main liquid chamber, 7: partition member, 8: damping orifice, 9: auxiliary Liquid chamber, 10: first diaphragm, 13: hole orifice, 27: internal pressure absorbing film, 28: adjustment chamber, 29: second diaphragm, 30: magnetic viscous fluid, 32: coil, 33: resistance plate, 37: internal pressure adjustment Means, 40: idle orifice, 43: open / close valve, 50: passage, 52: valve

Claims (7)

A first mounting member mounted on the vibration source side, a second mounting member mounted on the vibration receiving side, an insulator interposed therebetween for absorbing vibration, and a liquid in which the insulator forms part of a wall. And a liquid-sealing vibration isolator that divides the liquid chamber into a main liquid chamber and a sub-liquid chamber that are connected by a resonance orifice.
Providing an internal pressure adjusting means for the main liquid chamber, while adjusting the internal pressure absorbing capacity by this internal pressure adjusting means,
The internal pressure adjusting means includes: a first movable portion deformed or displaced by receiving the hydraulic pressure of the working fluid; an adjustment chamber in which at least a part of the wall portion is formed by the first movable portion; Provided, a magnetic viscous fluid, a second movable portion that is deformed or displaced to suppress a change in volume of the adjustment chamber, and a coil that generates a magnetic force to change the viscosity of the magnetic viscous fluid,
The internal pressure absorbing ability of the internal pressure adjusting means is controlled by changing the amount of deformation or displacement of the first movable portion by changing the viscosity of the magnetic viscous fluid by changing the magnetic force. 2. The liquid ring vibration isolator according to claim 1, wherein the internal pressure absorbing capacity is changed continuously or in multiple steps by changing the viscosity of the magnetic viscous fluid continuously or in multiple steps. 2. The liquid ring vibration isolator according to claim 1, wherein a flow resistance means for the magnetic viscous fluid is provided in the adjustment chamber. The said 1st movable part is an internal-pressure absorption film which consists of an elastic film which elastically deforms and absorbs internal pressure change, The said 2nd movable part is a diaphragm, At least one part is open-to-atmosphere, The Claims characterized by the above-mentioned. Item 6. A liquid-sealed vibration isolator according to Item 1. 2. The liquid ring vibration isolator according to claim 1, wherein said resonance orifice is a damping orifice. 2. The liquid-sealing prevention device according to claim 1, wherein the resonance orifice includes first and second orifices having relatively different resonance frequencies at different heights, and the second orifice having a higher resonance frequency is an opening / closing type. Shaking device. A hole orifice that communicates with the main liquid chamber with a predetermined opening diameter and surrounds the opening with an elastic film to generate liquid column resonance at a predetermined frequency is provided. 1. Liquid-sealed vibration isolator.

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