JP4571266B2 - Liquid seal vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid seal vibration isolator suitable for use in a vehicle engine mount and the like, and more particularly, to a device provided with a total of three orifices including first to third.
[0002]
[Prior art]
In a liquid seal engine mount for a vehicle, a first orifice having a resonance point in a frequency range of the 10 Hz range (hereinafter referred to as an input vibration range from a suspension) lower than an idle range such as shake vibration or choppy vibration is provided. Further, in addition to the first orifice, a second orifice that is openable and closable having a resonance point during idling of 20 to 30 Hz is known. Further, there is also known one provided with a third orifice having a resonance point at the start of the 40-60 Hz range.
[0003]
FIG. 5 schematically shows a typical example of a conventional liquid-sealed engine mount. An elastic body 3 such as rubber having a substantially conical shape is formed between a first mounting bracket 1 and a second mounting bracket 2. A liquid chamber having the elastic body 3 as a part of the wall portion is provided between the internal space and the second mounting bracket 2, and this liquid chamber is divided into the main liquid chamber 5 and the sub liquid chamber 7 by the partition member 4. It is partitioned. Secondary liquid chamber 7 is formed between the partition member 4 and diagram 6, first functioning as folder emissions ping orifice put the auxiliary liquid chamber 7 and the main liquid chamber 5 always communicates with the input vibration range from the suspension The orifice 8 is provided in the partition member 4.
[0004]
FIG. 6 is a schematic view similar to FIG. 5 in which a second orifice 9 functioning as an idle orifice is added to the liquid ring engine mount of FIG. 5. The second orifice 9 includes a main liquid chamber 5 and a sub liquid chamber 7. At the same time, the opening on the main liquid chamber 5 side is opened by the first valve 10 only during idling.
[0005]
FIG. 7 is a view similar to FIG. 6 in which a third orifice 11 is provided in addition to FIG. 6. This third orifice 11 functions as a starting orifice that blocks vibration during starting, and one end of the third orifice 11 is the main liquid. Opened into the chamber 5, the other end faces the secondary liquid chamber 7 and is covered with an elastic film 12 such as a rubber film.
[0006]
FIG. 3 is a graph showing the damping and dynamic spring characteristics of these conventional examples and the engine mount of the present invention. The horizontal axis represents frequency, the vertical axis represents dynamic spring constant K (N / mm), and the damping coefficient C (N · s). / M). Among these, the solid line relates to the present invention, and the broken line relates to the conventional example of FIG. Also, the imaginary line ○ 1 (meaning the circled number 1 and hereinafter expressed in the same way for the circled numbers 1 to 5) is the dynamic spring characteristic curve of the conventional example shown in FIG. The dynamic spring characteristic curves of the conventional example shown in FIG. “c” and “e” respectively indicate dynamic spring characteristics peaks caused by anti-resonance (maximum values in the dynamic spring characteristics curve, the same applies hereinafter) .
[0007]
First, the dynamic spring characteristic curve ○ 1 in the conventional example of FIG. 5 overlaps the solid line according to the present invention in the input vibration range from the suspension, and the bottom (minimum value in the dynamic spring characteristic curve, due to the resonance of the first orifice 8 ). The same applies to the following. A1 is generated to lower the dynamic spring constant, and the 10-Hz shake vibration and choppy vibration generated by the input vibration from the suspension are cut off. At the same time, the damping characteristic curve by the first orifice 8 shown as ○ 3 shows a peak b1 due to this resonance, and realizes a low dynamic spring and high damping in the input vibration region from the suspension to improve the riding comfort.
[0008]
However, the dynamic spring characteristic curve of this structure has a dynamic spring characteristic peak c in the 20 Hz range as an anti-resonance of the resonance by the first orifice 8, as shown by ◯ 1 , and becomes a high dynamic spring as it is. Therefore, by adopting the structure shown in FIG. 6, when the first valve 10 provided in the second orifice 9 is opened during idling, the dynamic spring characteristic produces a bottom d1 due to resonance of the second orifice 9 in the idling region. Realized low dynamic spring.
[0009]
On the other hand, as shown in the dynamic spring characteristic curve indicated by ○ 2 , when the peak e occurs in the starting region as the anti-resonance of the bottom d1 and this portion becomes a high dynamic spring, the vibration isolation at the time of starting becomes insufficient as it is There is. Therefore, when the structure of FIG. 7 is adopted, the elastic membrane 12 is vibrated in the anti-resonance region indicated by the dynamic spring characteristic curve ○ 2, and the liquid column resonance is generated in the third orifice 11 by this membrane vibration. It is possible to eliminate the peak e of the curve ○ 2 and generate the bottom f2.
[0010]
[Problems to be solved by the invention]
Thus, if the structure of FIG. 7 is adopted, a low dynamic spring at the time of start can be realized. However, in the conventional example shown in FIG. 7, the end of the third orifice 11 on the main liquid chamber 5 side is always open, so that the liquid pressure in the main liquid chamber 5 can be reduced even in the input vibration range from the suspension or in the idle range. Since it elastically deforms to absorb, each bottom a2 and d2 of the dynamic spring becomes a high dynamic spring compared to a1 and d1, and the entire characteristic curve also becomes a relatively high dynamic spring. In addition, as shown by the attenuation characteristic curve ◯ 4 , the peak b2 is lower than b1, so that the attenuation is lower than that of the characteristic curve ◯ 3 .
[0011]
In addition, since the dynamic spring characteristic curve after the bottom f2 is attached at the time of starting, a peak g due to anti-resonance is generated immediately after the starting, a high dynamic spring portion D that is desired to be removed in the starting region is generated. Therefore, even when the third orifice provided with the elastic membrane is provided, the dynamic spring can be lowered in the entire range of the idle region, the start region, and the input vibration region from the suspension, and high attenuation can be achieved in the input vibration region from the suspension. It is desirable to be able to achieve this. It is also desirable to lower the anti-resonance peak in other frequency bands other than the above, and to lower the dynamic spring in a wider range. The present invention aims to realize these requirements.
[0012]
[Means for Solving the Problems]
FIG. 1 is a diagram showing the principle of the present invention. In addition, the same code | symbol is used about a common part with the prior art example of FIGS. In this figure, the partition member 4 is provided with a first orifice 8, a second orifice 9 and a third orifice 1.
[0013]
The first orifice 8 always communicates with the main liquid chamber 5 and the sub liquid chamber 7 and resonates in an input vibration region from the suspension. The second orifice 9 resonates when the first valve 10 is opened in the idle region so that the main liquid chamber 5 and the sub liquid chamber 7 communicate with each other. The third orifice 11 has an opening end on the main liquid chamber 5 side that can be opened and closed by a second valve 13 so that it opens only when starting. The sub-liquid chamber 7 side of the third orifice 11 is covered with an elastic film 12 such as rubber so that the fluid flowing into the third orifice 11 can be vibrated.
When the frequency of the input vibration is in the resonance frequency range of the first orifice 8, the second orifice 9 and the third orifice 11 are closed by the first and second valves, respectively.
Open the first valve 10 in a frequency range where anti-resonance of the first orifice 8 occurs, resonate the second orifice 9, and leave the third orifice 11 closed by the second valve 13,
The second valve 13 is opened in a frequency range where anti-resonance occurs after resonance of the second orifice 9 to resonate the third orifice 11,
Further, the second valve 13 is closed after the resonance of the third orifice 11 and before the maximum value of the anti-resonance occurs .
[0014]
FIG. 2 is a diagram showing in principle the operation of only each orifice portion, with A showing the state of the input vibration region from the suspension, B showing the idle region state, and C showing the starting state. The diameters of these orifices increase in the order of first orifice 8 <second orifice 9 <third orifice 11. As for the third orifice 11, the second valve 13 can be provided on the sub liquid chamber 7 side, and the elastic film 12 can be provided on the main liquid chamber 5 side. In addition, it is not always necessary to provide the input vibration range from the suspension to the frequency range at the time of starting as described above, and by changing the purpose of each orifice, a band including a higher frequency range from a lower frequency range or It is also possible to target a band other than the input vibration range from the suspension to the frequency range at the start. However, in any of these cases, the resonance frequency of each orifice is set higher in the order of the first orifice, the second orifice, and the third orifice.
[0015]
【The invention's effect】
In FIG. 2, in the input vibration range from the suspension shown in A, the second orifice 9 is closed by the first valve 10, and the third orifice 11 is also closed by the second valve 13. Only 8 communicates the main liquid chamber 5 and the sub liquid chamber 7. As a result , as shown in the dynamic spring characteristic curve shown in FIG. 3, the dynamic spring constant in the input vibration range from the suspension produces the bottom a1, and the damping characteristic shows the peak b1, realizing a good high damping and low dynamic spring. To do.
[0016]
Further, as shown in B, in the idle region, the first valve 10 provided in the second orifice 9 is opened, and the second orifice 9 communicates with the main liquid chamber 5 and the sub liquid chamber 7, so that the first The liquid column resonance of the two orifices 9 occurs. As a result, in the idle region of FIG. 3, the dynamic spring constant produces a bottom d1, and a low dynamic spring can be realized. For third orifice 11 at this time remains the second valve 13 is closed, the amount of liquid fed to the second orifice 9 is sufficiently secured, what is dynamic spring characteristic curves shown in solid lines in FIG. 3 Thus, the spring can be made lower than in the conventional example.
[0017]
When the vehicle further starts, as shown in C, the second orifice 9 keeps the first valve 10 open (or closed), the third orifice 11 opens the second valve 13 and the fluid in the main liquid chamber 5 flows. third Ri into the orifice 11 input, since the oscillating elastic film 12, the fluid in the third orifice 11 produces a vibration by being vibrated liquid column resonance in the vertical direction of the elastic film 12. As a result, the peak e due to anti-resonance (see characteristic curve ◯ 2 in FIG. 3) in the second orifice 9 is extinguished.
[0018]
Therefore, in the starting region of FIG. 3, the dynamic spring constant eliminates the peak e due to the anti-resonance of the dynamic spring characteristic curve ◯ 2 , resulting in a bottom f1 lower than the bottom f2. Subsequently, when closing the second valve 13 again before the peak g should occur by the anti-resonance after the bottom f1 occurs, the fluid movement against the third orifice 11 is eliminated, after applying the bottom f1 at start The dynamic spring characteristic curve of FIG. 7 eliminates the anti-resonance peak g inevitably generated in the conventional example of FIG. 7, and does not cause the high dynamic spring portion D that is desired to be removed in the starting region.
In addition, the second valve 13 is closed in the input vibration region from the suspension and the idle region, and the elastic film 12 does not absorb the fluid pressure in the main fluid chamber 5 in these regions. A low dynamic spring by the two orifices 9 is realized. For this reason, even when the third orifice 11 provided with the elastic film 12 is provided, the dynamic spring characteristic of the conventional example shown by the broken line in FIG. 3 changes like the dynamic spring characteristic of the present invention shown by the solid line. Compared with the conventional example of FIG. 7 , a low dynamic spring can be realized in the entire range of the idle region, the start region, and the input vibration region from the suspension, and high damping can be realized.
[0019]
In addition, by changing the purpose of each orifice, the frequency range from the suspension to the input vibration range to the frequency range at the time of start can be applied to a band including a lower frequency range to a higher frequency range or another band. Even if the resonance frequency of each orifice is set higher in the order of the first orifice, the second orifice, and the third orifice, the same effect as described above, that is, the reaction to be caused by each of the first to third orifices. The peak of the dynamic spring characteristic due to resonance can be lowered, and a wider range of bands can be lowered, and the application can be expanded.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment configured as a liquid seal engine mount for an automobile will be described with reference to the drawings. FIG. 4 shows a specific example of the engine mount. The first mounting bracket 1 integrated with the central portion of the elastic body 3 is integrated with a bolt 20 for mounting to an engine (not shown) on the outer surface side. The main liquid chamber 5 side protrudes into the main liquid chamber 5 by forming a narrow neck portion 21, and a substantially dish-shaped medium-frequency device 22 is attached to the tip. The medium / high frequency device 22 causes liquid column resonance in the surrounding fluid in the medium / high frequency range (100 Hz to). In the present invention, 100 Hz or less is referred to as a low frequency, 100 to 500 Hz as a medium frequency, and 500 Hz or more as a high frequency.
[0021]
The elastic body 3 is made of a known material such as rubber, and is integrated with the first mounting bracket 1 at the center side, and the periphery of the skirt portion forms a flange 23 onto the outer flange portion 26 on the second mounting bracket 2 side. Integrated with baking. A thin cylindrical portion 24, which is a portion below the flange 23 of the elastic body 3, extends downward in the figure, and is baked and integrated into a main liquid chamber side cylindrical portion 27 that forms part of the second mounting bracket 2. It faces the liquid chamber 5. However, a hole 28 is provided in a part of the main liquid chamber side cylindrical portion 27 and the outer flange portion 26 integrated to the outside thereof, and a portion of the thin-walled cylindrical portion 24 covering the hole 28 is elastically deformable. One elastic film 25 is formed.
[0022]
An attachment arm portion 29 of the valve 13 is provided through the first elastic film 25 inward and outward, and the attachment arm portion 29 is connected to the drive member 30 on the outside. The drive member 30 is composed of an electromagnetic solenoid or the like, and is a known member that opens and closes the valve 13 by moving the mounting arm portion 29 in and out or up and down, and is supported by, for example, the outer flange portion 26.
[0023]
The lower portion of the main liquid chamber side cylindrical portion 27 forms an outer flange 31 and is connected here by caulking provided at the upper end portion of the lower side cylindrical portion 32 constituting the second mounting bracket 2. A cylindrical support member 34 is integrated inside the lower cylindrical portion 32 by welding, and the partition member 4 is interposed between an inner flange 35 formed at the upper end of the cylindrical support member 34 and an outer flange 31 of the main liquid chamber side cylindrical portion 27. The periphery and the periphery of the diagram 6 are clamped together.
[0024]
The partition member 4 is obtained by integrating three members, ie, an upper partition 36, an intermediate partition 37, and a lower partition 38, which are made of each resin. The upper partition 36 includes an inlet 40 that opens to the main liquid chamber 5 side, and has a side passage 40 a that is open on the lower side, and a central passage 41 that communicates with the central passage 41 and opens downward in the center of the upper partition 36.
[0025]
The lower side of the upper partition 36 abuts against the upper surface of the intermediate partition 37, the side passage 40 a is closed to form the second orifice 9, and the central passage 41 has an opening 42 formed at the center of the intermediate partition 37 and this. The outlet 43 that coincides and opens at the center of the lower partition 38 communicates.
[0026]
The other part of the upper partition 36 is provided with a passage 40b that is opened downward independently of the side passage 40a and the central passage 41, and the upper part of the upper partition 36 is connected to an entrance 45 opened on the upper surface of the upper partition 36. The main fluid chamber 5 communicates with the second valve 13, and the lower opening of the passage 40 b is covered by a part of the intermediate partition 37 from below, and the interior of the passage 40 b is formed by the third orifice 11. In addition, an opening is provided in a part of the intermediate partition 37, and the second elastic film 12 is attached to the opening.
[0027]
Further, an arcuate groove that opens upward in the figure is provided around the intermediate partition 37, and the first orifice 8 is formed by closing the opening with the upper partition 36. The first orifice 8 is not clearly shown in the figure, but communicates from the inlet provided in the upper partition 36 to the main liquid chamber 5, and is formed in the lower partition 38 and is closed by the intermediate partition 37. The other end of the arc-shaped passage 44 opens into the auxiliary liquid chamber 7. Since the arc-shaped passage 44 constitutes the first orifice 8, the first orifice 8 always communicates with the main liquid chamber 5 and the sub liquid chamber 7 as a damping orifice.
[0028]
These first valve 10 and second valve 13 are each controlled by a known method, for example, by detecting the engine speed and by a computer. In this case, the control based on the engine speed can be performed by previously defining the input vibration area from the suspension, the idle area, and the start area by the engine speed. However, an appropriate numerical value representing the operating state of another engine can be used for control instead of or together with the engine speed.
[0029]
The outlet 43 closes the second orifice 9 by pressing the thick portion 46 provided at the center of the diagram 6 with the first valve 10, and lowers the first valve 10 to exit the thick portion 46. The second orifice 9 is opened away from 43.
[0030]
The first valve 10 is formed by integrally covering the periphery of a cup-shaped core material 47 made of metal or resin with an elastic cover 48 such as rubber, and the upper center of the elastic cover 48 forms a pressing portion 49. Yes. Further, the elastic cover 48 is surrounded by a thin diagram portion 48a made only of an elastic body without the core material 47, and the entire valve 10 can be moved up and down.
[0031]
The outer periphery of the elastic cover 48 sandwiching the diagram portion 48a forms a thick annular wall 48b, and the reinforcing ring 50 is integrated inside thereof. The annular wall 48b is superposed on the resin bottom plate 51 and integrated by crimping the upper and lower ends of the support ring 52 welded to the lower inner side of the lower cylindrical portion 32.
[0032]
A pipe portion 53 is integrally provided at the center of the bottom plate 51, and the valve 10 and the bottom plate 51 communicate the formed sealed space 54 with an external negative pressure source (not shown). When the inside of the sealed space 54 is made negative by this negative pressure source, the valve 10 is lowered against the return spring 55 by the negative pressure, and the outlet 43 of the diagram 6 is opened.
[0033]
On the contrary, when the negative pressure is stopped, the valve 10 is raised by the return spring 55, and the thick portion 46 of the diagram 6 is pressed against the outlet 43 to close the outlet 43. In addition, the code | symbol 56 in a figure is a mounting flange provided in the lower part of the lower side cylindrical part 32, and is bolted to the vehicle body side which is not shown in figure here.
[0034]
Next, the operation of this embodiment will be described. As already described with reference to FIGS. 1 to 3, the third orifice 11 has the first orifice 8 and the second orifice 9 because the second valve 13 is closed in the input vibration region and the idle region from the suspension. Can exhibit a predetermined performance and realize a sufficiently low dynamic spring, and can obtain a sufficiently high damping in the input vibration region from the suspension.
[0035]
Further, when starting, the third orifice 11 can realize a low dynamic spring at the time of starting by opening the second valve 13, and then reclosing the second valve to resonate with the resonance at the time of starting. To eliminate the high dynamic spring immediately after starting. For this reason, since it is possible to realize a low dynamic spring in the start area including at the time of start and immediately after the start, it is possible to reduce the noise at the time of start and to reduce the start shock and improve the ride comfort.
[0036]
Moreover, since the second valve 13 operates via the first elastic film 25 provided on the side of the main liquid chamber 5, the second valve 13 can be operated using the elasticity of the first elastic film 25 and the sealing performance can be improved. . In addition, since the first elastic film 25 itself absorbs the increase in internal pressure in the main liquid chamber 5, it can contribute to the reduction of the overall dynamic spring.
[0037]
The first valve 10 and the second valve 13 are opened at the time of starting, but the opening diameter of the third orifice 11 is considerably larger than the opening diameters of the first orifice 8 and the second orifice 9. The liquid column resonance occurs only in the third orifice 11. Further, when the engine speed decreases to a predetermined value after the start, the first valve 10 and the second valve 13 that are simultaneously opened are closed to enter the state of the input vibration from the suspension, and the main liquid chamber 5 and the auxiliary liquid The fluid flows only into the first orifice 8 communicating with the chamber 7. However, the first valve 10 can be closed when starting.
[0038]
The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the principle of the invention. For example, the second valve 13 can be provided on the sub liquid chamber 7 side, and the elastic film 12 can be provided on the main liquid chamber 5 side.
[0039]
In addition, by changing the purpose of each orifice, the frequency range from the suspension to the input vibration range to the frequency range at the time of start can be applied to a band including a lower frequency range to a higher frequency range or another band. Even if the resonance frequency of each orifice is set higher in the order of the first orifice, the second orifice, and the third orifice, the same effect as described above, that is, the anti-resonance peak is lowered by the third orifice. A wider range of bands can be made into a low dynamic spring, and applications can be expanded.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing the principle of the invention of the present application. FIG. 2 is a diagram showing only the main part. FIG. 3 is a graph showing the dynamic spring constant and damping performance of the invention of the present application and the conventional example. Sectional view [Fig. 5] Schematic sectional view of conventional example [Fig. 6] Same as above [Fig. 7] Same as above [Explanation of symbols]
1: first mounting bracket, 2: second mounting bracket, 3: elastic body,
4: partition member, 5: main liquid chamber, 6: diagram, 7: secondary liquid chamber, 8: first orifice, 9: second orifice, 10: first valve, 11: third orifice, 12 : Elastic membrane, 13: Second valve

Claims (5)

An elastic body is interposed between the first and second mounting brackets, a liquid chamber having the elastic body as a part of the wall portion is provided, and the liquid chamber is partitioned into a main liquid chamber and a sub liquid chamber by a partition member, Liquid column resonance is generated by the vibration of the first orifice that always communicates with the main liquid chamber and the sub liquid chamber, the second orifice that can be opened and closed by the first valve, and the elastic membrane provided on the one end opening side. In the liquid seal vibration isolator provided with the third orifice, the resonance frequency of each orifice is set higher in the order of the first orifice, the second orifice, and the third orifice, and the diameters of these orifices are set to the first Second orifice 9 <second orifice 9 <third orifice 11 is increased in this order, and the opening end of the third orifice opposite to the side on which the elastic film is provided can be opened and closed. The valve of
When the frequency of the input vibration is in the resonance frequency range of the first orifice, the first and second valves are used to close the first orifice and the second orifice and the third orifice, respectively. Resonate,
After resonating the first orifice, opening the first valve to resonate the second orifice, and leaving the third orifice closed by the second valve;
Resonating the third orifice by opening the second valve in a frequency range where anti-resonance occurs after resonance of the second orifice;
Further, the liquid seal vibration isolator is closed by the second valve after the resonance of the third orifice and before the maximum value of the anti-resonance occurs .  The first orifice has a resonance point in an input vibration region from the suspension, the second orifice has a resonance point in an idle region, and the third orifice has a resonance point in a starting region. The liquid seal vibration isolator according to claim 1.   2. The opening diameter of the second orifice is larger than the opening diameter of the first orifice, and the opening diameter of the third orifice is larger than the opening diameter of the second orifice. Or the liquid seal vibration isolator described in 2.   4. The liquid seal prevention according to claim 1, wherein the second valve operates through an elastic film that forms a wall portion of the main liquid chamber and is formed of a part of the elastic body. Shaker.   5. The device according to claim 1, wherein when the second valve is opened, the first valve is in an open state, and thereafter, the first valve and the second valve are each closed. Liquid seal vibration isolator.

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