JP2004324826A - Liquid encapsulating vibrationproof device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid encapsulating vibrationproof device capable of solving a conventional problem where an orifice length changing means is used such that the rating changes of the resonance frequency and the phase become extreme to result in generation of a region in which the phase is insufficient between the changeover points. <P>SOLUTION: The liquid encapsulating vibrationproof device is configured so that a main liquid chamber 5 formed partially from an insulator 4 is put in communication with an auxiliary liquid chamber 8 through a damping orifice 7, and an internal pressure absorbing film 17 is installed on the wall of the main liquid chamber 5, and thereby the film tension and the orifice length are controlled by a film controlling means 18. The film controlling means 18 is equipped with an orifice length changing valve 13, a pushing member 20, and a solenoid 22 to advance them and retreat, wherein the pushing member 20 is furnished with a pushing surface 25 in the shape of stairs. When the pushing member 20 is pushed to the film 17 by the solenoid 22, the pushing area varies in compliance with the stroke amount, and the film tension changes non-linearly. When pulled to the opposite side, the valve 13 retreats to generate changing-over of the orifice length to the shorter side. <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 used for an engine mount of a vehicle, which has a resonance orifice and performs vibration isolation by resonance of a liquid column, and more particularly to a device capable of broadening a resonance frequency.
[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. And a liquid chamber partitioned into a main liquid chamber and a sub liquid chamber, which are communicated with each other through an orifice passage, and an internal pressure absorbing film is provided on a part of a wall surrounding the main liquid chamber. An internal pressure absorption type liquid ring engine mount in which the membrane tension is changed is known. In this type of engine mount, if the internal pressure absorbing film is softened, the internal pressure change is absorbed to make it a low dynamic spring, and if it is made rigid, the expansion spring, which is a spring generated by the change in the internal pressure of the engine mount, is raised. The flow rate to the orifice passage is increased, thereby increasing resonance efficiency and reducing vibration transmission.
[0003]
Also known is an orifice provided with an orifice length varying means for varying the orifice length. As shown schematically in FIGS. 17 and 18, this device is provided with an orifice length variable valve b integrated with the internal pressure absorbing film a, and the internal pressure absorbing film a and the orifice length variable valve b are combined with the membrane control means c. To move. The orifice length variable valve b changes its length by opening and closing a second inlet e formed at an intermediate portion of a long resonance orifice d. The resonance orifice d has a first entrance f at one end and an exit g at the other end (FIG. 18).
[0004]
As shown in FIG. 17, the distal end of the variable orifice length valve b moves up and down, and the variable orifice length valve b moves in the pulling direction (A direction). Open entrance e.
Therefore, the resonance orifice d having the length L1 of the first inlet f to the outlet g at the time of closing is changed to the length L2 of the second inlet e to the outlet g.
[0005]
[Problems to be solved by the invention]
17 and 18, the resonance frequency can be freely changed by setting the orifice length to L1 and L2. That is, there is the following relationship.
Resonance fn∝ (orifice length)-^1/2
At this time, since the tension in the tension direction acts on the internal pressure absorbing film a, the expansion spring is more likely to rise than usual, and the resonance efficiency is increased.
[0006]
[Patent Document 1] Japanese Patent Application Laid-Open No. 7-14335
[Patent Document 2] JP-A-8-320048
[Patent Document 3] JP-A-10-281214
[Patent Document 4] Japanese Patent Application Laid-Open No. 2001-18937
[Patent Document 5] JP-A-2001-280405
[Patent Document 6] JP-A-2002-250391
[Patent Document 7] JP-A-7-305740
[Patent Document 8] JP-A-2002-70930
[Patent Document 9] JP-A-2002-70931
[Patent Document 10] JP-A-2002-168284
[Patent Document 11] JP-A-2002-250392
[Patent Document 12] JP-A-2003-4090
[0007]
[Problems to be solved by the invention]
FIG. 19 shows the relationship between the resonance frequency and the phase peak in the above conventional example. As shown in this figure, when the control state of B (short orifice length) is changed to the non-control state of A (long orifice), both the phase and the resonance frequency sharply increase. However, since the resonance frequency rises extremely, the phase of the portion indicated by C cannot be covered. That is, since it is difficult to switch the continuous control, it is not possible to obtain the phase of the entire region requiring the phase.
[0008]
In addition, by providing the internal pressure absorbing film a, when not controlled, the internal pressure absorbing film a is freely elastically deformed to absorb the internal pressure fluctuation, and the Kf is reduced to make a low dynamic spring. On the other hand, during control, the tension of the internal pressure absorbing film a is generated by the film control means c, Kf is improved, and the orifice resonance is made more efficient. At this time, between the resonance frequency change Δfx and the Kf change ΔKf, Δfx∝ (ΔKf)¹/²
There is a relationship.
[0009]
As described above, the change in the resonance frequency when the film tension control is used occurs with respect to the change in Kf (ΔKf). , And the control frequency band Δfx is in a very limited range. Therefore, if a phase that is equal to or more than a predetermined phase is required in the region from the idle state to the start, the control frequency band Δfx in which such a phase is obtained is limited to a narrow range, and an effective cutoff effect is obtained in other regions. You will not get it. Therefore, it is desired to widen the control frequency band Δfx.
[0010]
For this purpose, it is conceivable to change the film tension change of the internal pressure absorbing film non-linearly with respect to the magnitude of the input vibration. When the film tension changes nonlinearly, ΔKf is increased, and the control frequency band Δfx can be expanded accordingly. Therefore, if the film tension of the internal pressure absorbing film can be changed non-linearly, the control frequency band Δfx can be expanded. Accordingly, an object of the present invention is to broaden the control frequency band Δfx by combining an orifice length varying unit and a film tension varying unit, and to continuously generate a high phase.
[0011]
[Means for Solving the Problems]
The liquid seal vibration isolator according to claim 1, wherein a first mounting member mounted on the vibration source side, a second mounting member mounted on the vibration receiving side, and an insulator interposed therebetween for absorbing vibration. An orifice for partitioning the liquid chamber into a main liquid chamber and a sub liquid chamber, communicating with each other through a resonance orifice, and changing the length of the resonance orifice. With length variable means,
In a liquid seal vibration isolator provided with an internal pressure absorbing film made of an elastic film that elastically deforms and absorbs a change in internal pressure, is provided on a part of a wall portion surrounding the main liquid chamber,
The orifice length variable means includes the resonance orifice having a normally open first entrance and an openable / closable second entrance, and an orifice length variable valve for opening and closing the second entrance.
A pressure member that is pressed against the internal pressure absorbing film, and a film tension varying unit that continuously or multi-stagely changes the tension of the internal pressure absorbing film according to the amount of advance / retreat stroke of the pressing member; The variable means and the orifice length variable means are integrated.
[0012]
According to a second aspect, in the first aspect, the orifice length variable valve is moved in any of front and rear, left and right, and up and down.
[0013]
According to a third aspect, in the first aspect, the internal pressure absorbing membrane is controlled by being moved to a position where the membrane tension is increased across a neutral position and a position where the second entrance is opened. I do.
[0014]
A fourth aspect of the present invention is characterized in that, in the first aspect, the pressing surface shape of the pressing member changes stepwise.
[0015]
A fifth aspect of the present invention is characterized in that, in the first aspect, the cross-sectional shape of the internal pressure absorbing film changes irregularly.
[0016]
A sixth aspect of the present invention is characterized in that, in the fifth aspect, a deformation regulating stopper is provided on the internal pressure absorbing film to make the sectional shape irregular.
[0017]
A seventh aspect of the present invention is characterized in that, in the fifth aspect, a positioning portion is provided at a center portion of the internal pressure absorbing film to make the cross-sectional shape irregular.
[0018]
An eighth aspect of the present invention is characterized in that in any one of the first to seventh aspects, the resonance orifice is an idle orifice and is used for controlling the resonance frequency.
[0019]
According to a ninth aspect of the present invention, in any one of the first to seventh aspects, the resonance orifice is a damping orifice, which is used to eliminate the frequency dependence of the liquid column resonance.
[0020]
According to a tenth aspect, in any one of the first to ninth aspects, the driving means of the pressing member is a solenoid or a negative pressure of intake air.
[0021]
【The invention's effect】
According to the first aspect, there is provided a film tension changing means for changing the tension of the internal pressure absorbing film continuously or in multiple stages according to the advance / retreat stroke amount of the pressing member, and the film tension changing means and the orifice length changing means are integrated. As a result, both means can be linked, a large change in resonance frequency and a high phase can be obtained by the orifice length variable means, and the intermediate region between both switching points can be controlled continuously or in multiple stages by the film tension variable means. Thus, the resonance frequency and phase can be changed. Therefore, the resonance frequency can be controlled in a wide frequency range and a high phase can be obtained. Moreover, since the membrane control means can be integrated with the membrane tension varying means and the orifice length varying means, it can be manufactured with a simpler structure and at lower cost than the conventional active type liquid ring vibration isolator. .
[0022]
According to the second aspect, the orifice length can be variably controlled by operating the internal pressure absorbing film and moving the orifice length variable valve forward, backward, left, right, up, or down.
[0023]
According to the third aspect, it is possible to change the orifice length by moving the internal pressure absorbing film to a position where the film tension is increased across the neutral position and changing the film tension, and moving the second inlet to a position where the second inlet is opened. . It can be easily realized by changing the elastic deformation direction with respect to the internal pressure absorbing film.
[0024]
According to the fourth aspect, since the pressing surface shape of the pressing member is changed stepwise, the pressing area can be easily changed depending on the stroke amount.
[0025]
According to the fifth aspect, by making the cross-sectional shape of the internal pressure absorbing film irregular, the film tension can be changed non-linearly with respect to the stroke amount of the pressing member.
[0026]
According to the sixth aspect of the present invention, since the deformation restricting stopper is provided on the internal pressure absorbing film, as the elastic deformation of the internal pressure absorbing film increases, the tension of the deformation restricting stopper increases, making it difficult for the internal pressure absorbing film to elastically deform. , The expansion spring can be increased non-linearly.
[0027]
According to the seventh aspect, since the positioning portion is provided at the center of the internal pressure absorbing film, it is possible to prevent the displacement of the pressing member during the stroke.
[0028]
According to the eighth aspect, by controlling the film tension of the internal pressure absorbing film at the time of idling, the resonance frequency can be widened, and a high phase can be obtained, so that vibration of a vector component which is difficult to be prevented is prevented. Vector control becomes possible, and vibration on the vehicle body side can be effectively suppressed.
[0029]
According to the ninth aspect, by controlling the film tension of the internal pressure absorbing film when the liquid column resonance occurs due to the damping orifice, it is possible to increase the phase generated by the resonance by controlling the change in the resonance frequency. Where the resonance frequency varies depending on the deformation amount and the deformation speed of the liquid ring vibration isolator, the resonance frequency can be maintained constant by the high phase, and the frequency dependence can be eliminated. .
[0030]
According to the tenth aspect, the driving means of the pressing member can be easily driven by using a solenoid or an intake negative pressure.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments will be described with reference to the drawings. 1 and 2 relate to a liquid ring engine mount common to the embodiments, FIG. 1 is a top view thereof, and FIG. 2 is a sectional view corresponding to line 2-2 in FIG. In the following description, “up and down” is based on the state in FIG.
[0032]
In FIG. 1, the liquid-tight engine mount 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), and the second mounting member 3 is connected to a vibration receiving side such as a vehicle body (not shown).
[0033]
As shown in FIG. 2, the insulator 4 is a well-known rubber vibration isolator having a substantially conical shape made of rubber. However, a known elastic vibration isolating member having a substantially conical shape made of a suitable elastic material such as rubber and other elastomers can be used, and the first mounting member 2 and the second mounting member 3 are connected and integrated. I do.
[0034]
A main liquid chamber 5 is formed inside the first mounting member 2, the second mounting member 3, and the insulator 4, and a well-known incompressible working fluid is sealed therein. The main liquid chamber 5 communicates with the sub liquid chamber 8 via a damping orifice 7 formed on the outer periphery of the partition member 6. The damping orifice 7 absorbs, with high damping, vibration during normal running which affects the riding comfort of low frequency and small amplitude of about 10 Hz. The sub liquid chamber 8 is covered by a diaphragm 9.
[0035]
The partition member 6 is formed by vertically integrating a resin or metal upper member 10, a rubber middle member 11, and a resin or metal lower member 12, and each is a disk-shaped member. The material is not particularly limited. The damping orifice 7 is formed on each of the three members at the outer periphery. 7b in the figure is an outlet.
[0036]
An intermediate portion of the damping orifice 7 communicates with the main liquid chamber 5 at a second inlet 7c formed in the upper member 10, and the main liquid chamber 5 can be opened and closed by an orifice variable length valve 13. The orifice variable length valve 13 is integrated with the internal pressure absorbing film 17. However, the orifice variable length valve 13 may be the same material as the internal pressure absorbing film 17 or a different material.
[0037]
Further, when the membrane control means 18 is retracted, that is, when the pressing member 20 is retracted to elastically deform the internal pressure absorbing film 17 outward, the orifice variable length valve 13 is retracted to open the second inlet 7c, The damping orifice 7 is switched to a short path from the second entrance 7c to the exit 7b.
[0038]
The peripheral wall of the main liquid chamber 5 is constituted by an upper cylindrical member 14 which is a part of the second mounting member 3 and a cylindrical elastic wall 15 which covers the inside thereof. The cylindrical elastic wall 15 is an extension formed continuously and integrally with the insulator 4. An opening 16 is formed in a part of the upper cylindrical member 14, and a portion of the cylindrical elastic wall 15 overlapping the opening 16 is an internal pressure absorbing film 17. The internal pressure absorbing film 17 is an elastic film made of an appropriate elastic material such as rubber, and has a spring capable of affecting the internal pressure of the main liquid chamber 5. In this embodiment, it is integral with the cylindrical elastic wall 15, but this part may be formed as a separate member and have different spring constants.
[0039]
Outside the internal pressure absorbing film 17, that is, on the opposite side of the main liquid chamber 5 with the internal pressure absorbing film 17 interposed therebetween, a film control means 18 is provided and supported on a flange 19 at the lower end of the upper cylindrical member 14 or by another member. I have. The film control means 18 serves both as a film tension changing means and an orifice length changing means, and both means are integrated as the film control means 18. The membrane control means 18 includes a pressing member 20 pressed against the internal pressure absorbing film 17, and a solenoid 22 for allowing the armature 21 integrated with the pressing member 20 to move in the axial direction. The armature 21 is made of a magnetic material, and advances and retreats with respect to the internal pressure absorbing film 17 depending on the direction of the line of magnetic force generated by the solenoid 22, and the stroke amount is proportional to the strength of the magnetic field generated by the solenoid 22.
[0040]
The control of the drive current for the solenoid 22 is performed by the control device 23, and is controlled based on the detection signal of the rotation sensor 24 that detects the engine speed. The sensor signal serving as the basis of the control is not limited to the rotational speed, but may be another appropriate sensor detection amount indicating the operation state of the engine or a sensor detection amount related to direct input vibration. The driving means is not limited to the solenoid 22, and various known means such as negative pressure of intake air of the engine can be used.
[0041]
An idle orifice 26 is formed between the upper member 10 and the middle member 11. The idle orifice 26 communicates with the main liquid chamber 5 and the sub liquid chamber 8 to generate a liquid column resonance at an engine vibration frequency during idling to reduce the dynamic spring. Vibration transmission to the mounting member 3 is cut off. The idle orifice 26 is openable and closable.
[0042]
The outlet 26a of the idle orifice 26 on the side of the auxiliary liquid chamber 8 is openable and closable by an idle opening / closing valve 27 formed in the center of the diaphragm 9, and is open only in an idle frequency range, and is closed in other cases. The idle opening / closing valve 27 is pressed by the head 31 of the telescopic member 30 and is opened and closed by the expansion and contraction of the telescopic member 30.
[0043]
A hollow negative pressure chamber 33 is formed between the head 31 and the bottom 32 of the elastic member 30. The negative pressure chamber 33 is configured to switch the connection between the intake negative pressure and the atmosphere via a ventilation nozzle 34. When the intake negative pressure is applied, the idle open / close valve 27 moves downward in the figure against the return spring 35 to open the outlet 26a, and shuts off the intake negative pressure to open to the atmosphere. Move upward to close outlet 26a.
[0044]
FIG. 3 is a diagram showing the resonance orifice structure as viewed from above in FIG. 2 (top view). The damping orifice 7 is formed in the partition member 6 to meander in a substantially S-shape, and one end thereof is a first entrance. 7a, and the other end forms an outlet 7b. A second inlet 7c is provided halfway between the first inlet 7a and the outlet 7b, and an orifice variable length valve 13 is provided here so as to be freely opened and closed. The idle orifice 26 is formed separately from the damping orifice 7 at the center of the partition member 6.
[0045]
FIG. 4 is an enlarged sectional view of the membrane control means 18. The orifice variable length valve 13 is slidably advanced and retracted on a step 10a formed on the shoulder of the upper member 10.
In this example, the outer peripheral side of the second inlet 7c is higher, the lower surface of the orifice variable length valve 13 facing the second inlet 7c forms a tapered surface 13a whose outer peripheral side is directed upward, and the outer peripheral portion 7d of the second inlet 7c is An engaging projection 13b is formed. When the second inlet 7c is closed, the projection 13b engages with the outer peripheral portion 7d and does not open even if the orifice variable length valve 13 retreats.
[0046]
However, when the orifice variable length valve 13 is retracted with a larger force, the projection 13b moves over the outer peripheral portion 7d and moves to the outer peripheral side. At this time, since the orifice variable length valve 13 swings by tilting the free end side upward by the projection 13b, the opening of the second entrance 7c can be expedited. When the orifice variable length valve 13 is advanced with the second inlet 7c closed, the orifice variable length valve 13 can move on the step 10a while maintaining the closed state.
[0047]
Next, a first embodiment of the film tension control will be described with reference to FIGS. The pressing surface 25 of the pressing member 20 pressed against the internal pressure absorbing film 17 changes stepwise. Since the pressing area of the internal pressure absorbing film 17 pressed by the pressing member 20 changes according to the stroke amount of the pressing member 20, the film tension of the internal pressure absorbing film 17 changes. As a result, when the film tension of the internal pressure absorbing film 17 increases, the expansion spring, which is a spring generated by a change in the internal pressure in the vibration isolator, increases. The adjustment of the membrane tension of the internal pressure absorbing membrane 17 can be controlled either in multiple stages or continuously.
[0048]
The pressing surface 25 has a stepped shape, and between the inner surface and the internal pressure absorbing film 17, the tip (top) 25 a forms an initial clearance d 0, the next stage 25 b changes to d 1, and the next stage 25 c changes to d 2. The lowermost stage 25d forms d3. Then, when the pressing member 20 is pushed out by the solenoid 22, as shown in FIGS. 6A to 6C, the pressing area where the internal pressure absorbing film 17 is pressed changes from S1 to S3 with the pressing displacement amounts of d1 to d3.
[0049]
FIG. 7 is a graph showing the effect on the internal pressure absorbing film 17 due to the change in the stroke amount of the pressing member 20. As shown by a solid line according to the change in the amount of pressing displacement of the pressing member 20, the holding area is As a result, the area of the internal pressure absorbing film 17 that can be freely elastically deformed decreases, and the film tension changes in multiple steps, as a dotted line, as a whole, rising to the right. At this time, the inclination of the broken line portion of the film tension corresponding to each pushing displacement amount increases and changes in multiple stages from θ1 to θ3, and changes to θ1 <θ2 <θ3.
[0050]
When the membrane tension changes in multiple stages, the expansion spring increases in multiple stages in accordance with the membrane tension. Therefore, if the pushing displacement amount is controlled to d1 to d3, a non-linear Kf change can be obtained. That is, by making the film tension non-linear, ΔKf can be increased and Δfx can be increased.
[0051]
Next, the operation will be described. In FIG. 4, in a normal state (non-operating state), the orifice length variable valve 13 exists at the neutral position (N), and the internal pressure absorbing film 17 freely vibrates. However, at the time of a large input, the displacement is restricted by the interference between the pressing member 20 and the internal pressure absorbing film 17.
When the pressing member 20 is moved in the (+) direction by the solenoid 22 as the first stage from the neutral position, the film tension of the internal pressure absorbing film 17 increases stepwise for the reason described later, and the resonance frequency gradually increases.
[0052]
Subsequently, as a second step, the pressing member 20 is pulled in the (-) direction by the solenoid 22, and the orifice length variable valve 13 is retracted to open the second inlet 7c. This shortens the damping orifice 7 and further raises the resonance frequency. In this switching state, since the internal pressure absorbing film 17 is elastically deformed outward and moves in the pulling direction, stepwise control of the film tension cannot be performed.
[0053]
FIG. 8 shows a phase change in this control. When the resonance frequency fn on the horizontal axis is between f1 and f2, the film tension control is the first stage, and the phase increases with the resonance frequency. Subsequent f2 to f3 are the orifice length switching states in the second stage. At this stage, the resonance frequency f3 becomes the highest and the phase also becomes the highest.
Therefore, the change range of the resonance frequency is widened to f1 to f3, and a high phase can be secured. Δ1 in the graph is a necessary level, and f1 to f3 satisfy this level.
[0054]
9 to 11 show variations of the orifice variable length valve 13. FIG. 9 shows a second embodiment, in which the orifice variable length valve 13 is formed with a hole 13c on the free end side, and in the normal state A, the hole 13c is shifted from the second inlet 7c. However, at the time of the control shown in B, since the orifice variable length valve 13 is retracted and the hole 13c comes above the second inlet 7c, the second inlet 7c is opened. By doing so, the operation becomes smooth because the up-and-down movement of the orifice variable length valve 13 is not accompanied.
[0055]
FIG. 10 shows a third embodiment. When the pressing member 20 moves forward and backward, the orifice variable length valve 13 rotates to open the second inlet 7c. That is, as shown in the enlarged portion, the orifice variable-length valve 13 is formed integrally with the cylindrical elastic wall 15 so as to protrude from the cylindrical elastic wall 15 so as to cover the second inlet 7c at normal times. Further, the distal end side of the pressing portion 13c, which is rotatable at the neck 13d and protrudes from the pressing member 20 toward the center of the main liquid chamber, is in contact with the neck portion 13d.
[0056]
However, this portion may be continuously integrated with the orifice variable length valve 13, or may be separated and brought into contact with each other. When the hole 13c is moved forward, the orifice variable length valve 13 rotates around the neck 13d as a fulcrum, and opens the second entrance 7c. This operation direction is referred to as a lateral direction. In this case, the orifice variable length valve 13 is slid in the lateral direction by pushing the pressing member 20, so that the stroke amount of the pressing member 20 does not need to be so large, and the opening / closing control of the orifice variable length valve 13 is performed. It can be advantageous.
[0057]
FIG. 11 is a sectional view showing the movement of the orifice variable length valve 13 at this time. The orifice variable length valve 13 slides on a slope 10 b formed on the upper surface of the upper member 10. In this way, the orifice variable length valve 13 is brought into close contact with the restoring elasticity of the neck 13d bent to the slope 10b, so that it is possible to prevent occurrence of a tapping sound.
The opening / closing operation of the orifice variable length valve 13 is not limited to the front and rear and the lateral direction, but may be in the vertical direction.
[0058]
12 to 15 show a fourth embodiment. As shown in FIG. 12, in this embodiment, the pressing member 20 has a substantially shell shape, and the pressing surface 25 has a continuous substantially streamlined shape. When the pressing member 20 is continuously pushed out toward the internal pressure absorbing film 17, as shown in FIGS. 13A to 13C, the pressing portion 20 presses the internal pressure absorbing film 17 in the pressing member 20 in accordance with the pressing amount x. The area increases and changes. Therefore, the pressing area of the pressing member 20 is correspondingly increased.
[0059]
FIG. 14 is a graph corresponding to FIG. 7 and shows the effect on the internal pressure absorbing film 17 due to the change in the stroke amount of the pressing member 20, and the solid line according to the change in the pushing displacement amount of the pressing member 20. As shown by, the holding area increases in a straight line rising to the right, and as a result, the area of the internal pressure absorbing film 17 that can be freely elastically deformed decreases. It changes in shape. Therefore, the non-linear change is performed steplessly and continuously. Therefore, this can further simplify the structure.
[0060]
FIG. 15 shows the relationship between the change of the resonance frequency and the phase in the film tension control in the first and fourth embodiments, where fa and fb are the required frequencies for the reference phase δ1, f1 is the resonance frequency in the free state, and f2 Is the maximum controllable resonance frequency when only the film tension is changed, and f3 is the maximum controllable resonance frequency when the holding area is changed.
As is clear from this figure, Δf (1-2) when only the film tension is changed and Δf (1-3) when the holding area is changed are Δf (1-2) <Δf (1- 3), and Δf can be broadened accordingly. The dotted line is an example of the related art having only one resonance frequency.
[0061]
Therefore, when the expansion spring is increased in the damping frequency range, the frequency dependency can be eliminated. That is, in the damping frequency range, it is known that the resonance frequency changes when the damping force changes, but by increasing the phase, it is possible to prevent the change in the resonance frequency and make the resonance frequency constant. it can.
[0062]
In the idling frequency range, vector control is required to suppress bending vibration on the vehicle body side.However, since the resonance frequency is widened and the phase becomes higher as the resonance frequency becomes higher, vector control becomes possible. Therefore, bending vibration of the vehicle body can be effectively suppressed.
[0063]
FIG. 16 shows a fifth embodiment relating to the regulation of the external deformation of the internal pressure absorbing film 17, in which a stopper 17a is formed integrally with the internal pressure absorbing film 17 and forms a ring-shaped leg which opens obliquely in the outer peripheral direction. The pressing member 20 is pressed against the stroke passage 28. With this configuration, when the internal pressure absorbing film 17 is bent toward the pressing member 20 and elastically deforms, the stopper 17a is strongly pressed against the stroke passage 28 and stretches as the amount of elastic deformation increases. The expansion spring can be increased by making it difficult to deform, and the input to the internal pressure absorbing film 17 can be dispersed to increase the internal pressure. In addition, since the stopper 17a is always in contact with the stroke passage 28, a structure for preventing interference noise with the pressing member 20 can be achieved.
[0064]
In addition, by making the cross-sectional shape on the side of the internal pressure absorbing film 17 irregular, a change of the expansion spring according to the stroke amount of the pressing member 20 can be realized. The stopper 17a in FIG. 16 is a specific example of this. Further, a columnar positioning portion 17b may be integrally formed at the center of the internal pressure absorbing film 17 so as to protrude. The projecting end of the positioning portion 17b is fitted into a positioning recess 25e provided on the top 25a of the pressing member 20. In this manner, the displacement of the pressing member 20 due to the stroke can be prevented, and the initial deformation portion is formed at a stage where the stroke amount is small.
[0065]
The present invention is not limited to the above embodiments, and various modifications and applications are possible within the principle of the present invention. For example, various types of driving means for the pressing member are possible, but it is also possible to use suction force due to negative intake air pressure of the engine. In this case, the air is supplied instantaneously from the intake passage side serving as a negative pressure supply source. Further, the present invention can be applied to an appropriate liquid-sealed vibration isolator other than the engine mount.
[Brief description of the drawings]
FIG. 1 is a top view of a liquid-sealed engine mount according to an embodiment.
FIG. 2 is a sectional view taken along line 2-2 in FIG.
FIG. 3 is a schematic top view of the membrane tension control structure according to the first embodiment.
FIG. 4 is a sectional view of the same.
FIG. 5 is a diagram showing a membrane tension control structure.
FIG. 6 is an explanatory diagram of the film tension control.
FIG. 7 is a graph showing a change in a holding area and a change in membrane tension.
FIG. 8 is a graph showing a change in resonance frequency and a change in phase peak.
FIG. 9 is a schematic sectional view of a membrane tension control structure according to a second embodiment.
FIG. 10 is a schematic top view of a membrane tension control structure according to a third embodiment.
FIG. 11 is a view showing the operation of the orifice length variable valve according to the third embodiment.
FIG. 12 is a view corresponding to FIG. 5 according to a fourth embodiment.
FIG. 13 is a view corresponding to FIG. 6 according to a fourth embodiment.
FIG. 14 is a view corresponding to FIG. 7 according to a fourth embodiment.
FIG. 15 is a graph showing a widening of a resonance frequency by a film tension control.
FIG. 16 is a diagram showing a film tension control structure according to a fifth embodiment.
FIG. 17 is a cross-sectional view showing a film control principle in a conventional example.
FIG. 18 is a schematic top view of the same.
FIG. 19 is a diagram showing a relationship between a resonance frequency and a phase peak by orifice length variable control.
[Explanation of Signs] 1: Liquid ring engine mount, 2: First mounting bracket, 3: Second mounting bracket, 4: Insulator, 5: Main liquid chamber, 6: Partition member, 7: Damping orifice, 7a: First Inlet, 7b: outlet, 7c: second inlet, 8: auxiliary liquid chamber, 9: diaphragm, 13: variable orifice length valve, 17: internal pressure absorbing membrane, 18: membrane control means, 20: pressing member, 22: solenoid , 25: pressing surface, 26: idle orifice

Claims (10)

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 an orifice length varying means for dividing the liquid chamber into a main liquid chamber and a sub liquid chamber, communicating with each other through a resonance orifice, and changing the length of the resonance orifice.
In a liquid ring vibration isolator provided with an internal pressure absorbing film made of an elastic film that elastically deforms and absorbs a change in internal pressure on a part of a wall surrounding the main liquid chamber,
The orifice length variable means includes the resonance orifice having a normally open first entrance and an openable / closable second entrance, and an orifice length variable valve for opening and closing the second entrance.
A pressure member that is pressed against the internal pressure absorbing film, and a film tension varying unit that continuously or multi-stagely changes the tension of the internal pressure absorbing film according to the amount of advance / retreat stroke of the pressing member; A liquid ring vibration isolator wherein variable means and said orifice length variable means are integrated. 2. The liquid ring vibration isolator according to claim 1, wherein the orifice length variable valve is moved in any of front and rear, left and right, and up and down. 2. The liquid ring vibration isolator according to claim 1, wherein the internal pressure absorbing film is controlled by being moved to a position where the film tension is increased across a neutral position and a position where the second entrance is opened. 2. The liquid ring vibration isolator according to claim 1, wherein the pressing surface shape of the pressing member changes substantially stepwise. 2. The liquid ring vibration isolator according to claim 1, wherein the cross-sectional shape of the internal pressure absorbing film changes irregularly. 6. The liquid ring vibration isolator according to claim 5, wherein a deformation regulating stopper is provided on the internal pressure absorbing film to make the cross-sectional shape irregular. 6. The liquid ring vibration isolator according to claim 5, wherein a positioning portion is provided at a center portion of the internal pressure absorbing film to make the cross-sectional shape irregular. The liquid ring vibration isolator according to any one of claims 1 to 7, wherein the resonance orifice is an idle orifice, and is used for controlling a resonance frequency thereof. The liquid ring vibration isolator according to any one of claims 1 to 7, wherein the resonance orifice is a damping orifice, and is used to eliminate frequency dependence of liquid column resonance. The liquid ring vibration isolator according to any one of claims 1 to 9, wherein the driving means for the pressing member and the orifice length variable valve is a solenoid or an intake negative pressure.

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