JPS62220731A - Vibration isolator encapsulating liquid - Google Patents

Abstract

PURPOSE:To damp the vibration of loss factor frequency which is different from orifice to orifice effectively by providing a diaphragm chamber dedicated for each orifice. CONSTITUTION:The low frequency components in the vibration of a power unit are damped sufficiently by means of the first and second diaphragm chambers 31, 32. In other word, the low frequency components are damped when the working liquid in a liquid chamber 25 moved through the first and second orifices 34, 35 between the liquid chamber 25 and the first and second diaphragm chambers 31, 32 as a rubber member 24 deforms. Consequently, respective loss factor peaks can be set at high levels without influence of other orifices.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid-filled vibration isolator, and more particularly to a liquid-filled vibration isolator that has a vibration damping range of an elliptical number by providing a plurality of orifices. .

2. Description of the Related Art As a conventional liquid-filled vibration isolator of this kind, for example, there is one disclosed in Japanese Patent Application Laid-open No. 72741/1998.

However, in this liquid-filled vibration isolator, a plurality of orifices are provided in one common diaphragm chamber, and among these orifices, there is a loss in the orifice on the side with a large liquid passage resistance. Even if a factor encounter occurs, the orifice on the side with smaller liquid passage resistance will be valved and the liquid will easily move. Therefore, the loss factor peak value l+1 in the frequency band served by the orifice on the side with larger 1fl overresistance becomes significantly smaller than the loss factor peak value in the frequency band served by the orifice on the side with smaller passing resistance (Fig. 8). (See ■). As a result, the effect of providing a plurality of orifices'+r was not fully demonstrated,
The configuration of only one orifice is little different from its counterpart.

By the way, the peak values of the respective loss factors generated by the plurality of orifices are set to approximately the same magnitude, that is, the loss factor characteristic is It is well known that the loss factor in the frequency band near the peak value can be set to a large value, so the most dynamic attenuation region can be widened. The liquid-filled vibration isolator is designed to fully utilize the loss factor generation function of each orifice without affecting other orifices, and to make the heights of the loss factor peak values of each orifice approximately equal. C has already been developed (Special Fly-1)
No. 95210).

That is, this liquid-filled vibration isolator 1 is constructed between the first frame 2 and the second frame 8, which are located on the power unit side (not shown) and on the vehicle body side, as shown in Figure 8g6.

A liquid chamber 6 is provided which is surrounded in a liquid-tight manner by a rubber body 4 which is an elastic body. At the upper and lower ends of this liquid chamber 5,
A first partition plate 6 is integrally extended from the frame body 2, and a second partition plate 7 is provided at the lower end of the second frame body B.
, and the upper part of the first partition plate 6 is covered with a first diaphragm 8 in a liquid-tight manner, and the lower part of the second partition root 7 is covered with a second diaphragm 9 in a liquid-tight manner. A first diaphragm chamber 10 is formed between the first partition plate 6 and the first diaphragm 8, and a second diaphragm chamber 11 is formed between the second partition plate 7 and the second diaphragm 9. - The first partition plate 81CDb is formed with a labyrinth-shaped first orifice 12 that communicates with the liquid chamber 5 and the first diaphragm chamber 8, and the second partition plate 7 is formed with a first orifice 12 that communicates with the liquid chamber 5 and the first diaphragm chamber 8. A labyrinth-shaped second orifice 18 communicating with the second diaphragm chamber 11 is formed.

Further, the peripheral edge of the first frame body 20 is caulked to the peripheral edge of the first MI mounting plate 14 that covers the first diaphragm 8, sandwiching the frame plate 8ai of the first diaphragm 8. on the other hand,
The periphery of the second frame H is caulked and fixed to the periphery of the second covering plate 16 located below the second diaphragm 9, sandwiching the periphery of the second partition plate 7 and the periphery of the second diaphragm 9. There is.

So, what is the passage length of the first orifice 12? Is it formed relatively short and the peak frequency of the loss factor? Large can
In addition to setting the passage length of the second orifice 18? Is the peak frequency of the loss factor formed relatively long? It is set small. −to.

Increase the wall thickness r of the first diaphragm 8 and the inner thickness of the second diaphragm 9 to increase rigidity? The expansion elasticity of the second diaphragm is set to be high. This
As a result, the loss factor characteristics of all the orifices have approximately equal peak values connected by a smooth curve, and a high loss factor Ij[k can be obtained over a wide range It's about to start work.

However, in the above-mentioned Japanese Patent Application No. Sho Fly-1915210, the first diaphragm chamber 10 and the second diaphragm chamber 11 are vertically separated with six liquid chambers in between. Since they are arranged in a good condition and each is constructed separately and independently, the structure becomes rough.

In addition, each 1st and 2nd frame for each 2.8 pieces? ! 1
There is a problem in that the manufacturing work becomes complicated and the cost increases, as it has to be separately caulked and fixed to the FLLF plates 14 and 15.

- Also, in each of the above-mentioned conventional liquid-filled protection bodies,
My friend, there has been no effort to suppress the dynamic spring constant against medium and high frequency vibrations such as engine movement and muffled noise, and there is no way to sufficiently reduce the body sensation.

Means for Solving Problems This invention provides a method in which a liquid chamber surrounded by an elastic body is dedicated to a number of orifices having different peak frequencies of loss factors, and each diaphragm chamber is dedicated to the orifice. A liquid-filled prevention body is provided in which the diaphragm expansion elasticity t of each of the diaphragm chambers and the loss factor peak frequency of the corresponding orifice are set as high as the white ones are, and the diaphragm chambers r1 of each diaphragm chamber are A diaphragm chamber valve is formed integrally with the diaphragm chamber, and a partition & in which the upper part of the diaphragm chamber on the liquid chamber side is fixed and the dedicated orifice is formed is provided at the bottom so as to be able to move slightly in the axial direction of the diaphragm chamber. T? It is a feature.

Function If this invention with the above structure is constructed, a diaphragm chamber dedicated to each orifice is provided. Does it mean that each orifice has a different frequency of vibration? .

We can effectively relieve our sorrow through our respective Oriais meetings.

In addition, the applicant has confirmed that the peak value of the loss 7 actor exerted in each orifice is proportional to the magnitude of this peak frequency, and inversely proportional to the magnitude of the diaphragm tension elasticity of the diaphragm chamber. Therefore, if the diaphragm expandable elastic tube is configured as described above, the loss factor beaks of each orifice can be made substantially equal.

Moreover, in the high-frequency wheeze region of the vehicle body, the partition plate defining the upper part of the diaphragm chamber moves slightly in the axial direction of the diaphragm chamber, but the dynamic spring constant is suppressed by straining. It is possible to sufficiently reduce vibration-SV.Furthermore, since each diaphragm chamber is integrally formed,
Not only is the structure simple, but it also has a vibration-proof structure! Li! You can fully improve your manufacturing efficiency.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows a first embodiment of the present invention, in which a power unit (not shown), a power unit (not shown), a first support frame 22, a second support frame 28, and a second support frame 28 are attached to the liquid-filled vibration isolator 21. (RW) Between the first and second support frames 22 and 28, a filtrate chamber 25 is provided which is liquid-tightly surrounded by a rubber body 24 which is an elastic body, and has a large diameter. The second diaphragm 80 in the form of a disc is airtightly separated from the liquid chamber 25, and an air chamber 26 is provided.
At the bottom of 5.

A toilet bowl-shaped partition wall 27 having a circular hole 27a is provided at the center of the upper part, and this partition wall 27 and the second diaphragm 26
A disk-shaped first diaphragm 29 fixed to the annular plate 28 is fixed between the annular plate 28 and the annular plate 28. And % 0 first diaphragm 29? A first diaphragm chamber 81 and an m2 diaphragm chamber 82 are integrally formed above and below the valve.

′! In addition, the partition wall 27i is provided with 88 relatively thick disk-shaped partition plates 88 in which an outer circumferential groove 83a is loosely fitted into the hole edge of the circular hole 27a. The top of? It is designed to be separated from the liquid chamber 25, and the outer circumferential groove 8Ra'i can be slightly moved up and down (about 0.4 RIB). Further, the first diaphragm chamber 81 communicates with the liquid chamber 25 through a short first orifice 84 bored approximately in the center of the partition plate 38 . - Just in case.
J! 2 diaphragm chamber B2rI% 1st diaphragm 29
A second annular orifice 85 is provided at 11JI between the partition wall 27 and the annular plate 28 near the outer periphery and communicates with the barb 25. The 42 orifice 85 has openings 85a and 85b, one end of which is formed in the end of the partition wall 27, and the other end formed in the annular plate 28, respectively. Then, the first orifice 84 is formed short and the peak frequency of the loss factor is set high, while the second orifice 81S is formed long in an annular shape and the peak frequency of the loss factor is set small. There is.

F again. The thickness of the first diaphragm 29 is as follows.

Is the second diaphragm 80 thick and rigid? The expansion elasticity of the first diaphragm 29 is set to be 1% higher than the expansion elasticity L') of the second diaphragm 80. This value t'L was determined based on an experiment conducted by the inventors of the present application, which showed that the peak frequency of the loss factor due to the orifice increases as the expansion elasticity of the diaphragm increases.

The outer periphery of each of the second diaphragm 80, the partition wall 27, and the annular plate 28 is connected to the second support frame 2B.
It is clamped between the outer circumferential edge 2Ra of the rubber body 24 and the outer circumferential edge 88a of the annular frame 86 that crushes the outer side of the rubber body 24, and is integrally fixed by caulking in an n7t-shape. In this way, each diaphragm chamber 31, 82, etc. can be formed in one caulking process, thereby improving manufacturing efficiency.

Therefore, in this embodiment, the lowest frequency component of the power unit 1 is the first. Second diaphragm chamber 81
．． 1 (2, etc.) The high frequency components should be sufficiently attenuated by the action of the rubber body 24, the partition plate 88, etc. 2
The working liquid (e.g., water) in the diaphragm 5 moves between the liquid chamber 2fi and the first and second diaphragm chambers 81 and 82 through the x-th and J2 orifices H4 and RISQ. It has become. The loss factor peak frequency of the orifice 84 is set in a frequency band that is among the lowest in low frequency performance, and the second orifice R is long.
The loss factor bee 2 frequency of 6 is set to one of the lowest frequencies among the low frequencies, and vibration damping of each frequency band is effectively performed. Note that in this embodiment, the liquid-filled moisture proof body 2
1 is used to support the power unit, and is set to an engine shake of 5 to 20 H2, and the loss factor beef frequency f,' (5 to 8 Hz) on the low frequency side is
.

Loss factor peak frequency Rf * k I on the high frequency side
It is set around R to 18 Hz, and chinning is performed so as to cover the eye movement frequency of the engine shake with loss 7 actor characteristics having crL and both peak circumferences nf, , f, and y.

FIG. 2 is a model diagram of the liquid-filled moisture-proofing body 21 in which the same components as those in FIG. In addition, the positive input direction spring b of the rubber body 24 is shown in the figure.
Spring due to expansion elasticity.

, is the g bale elasticity Kd of the first diaphragm 29, the spring, K
3, 42, expansion elasticity Kd of diaphragm 80, and air chamber 2.
Spring according to the phase with the 9 air spring of 6, I” * * In
M-bottle 1. Liquid mass in second orifice 84.85.

A, equal cross-sectional area in the liquid chamber 26, A, ,A, is the 11th
Equal cross-sectional area of the second diaphragm 29.80, S! +81
Iig],,@'a orifice) 14.86 opening area, it! , it, is the first. 2nd orifice R4゜85
Indicates the length.

The following table shows the expansion elasticity Kd++Kdt of the first diaphragm 29 and the second diaphragm 80 based on the above model.
? % This is the result of an experiment in which L was changed so that the desired loss factor characteristic was obtained.

Figure 8a shows the loss factor characteristics when the diaphragm expansion elasticity in the table above is changed, and the characteristics fII and l in the figure are shown.
ds Expansion elasticity Kd1 of the first diaphragm 29 is 46J
c9/m, 9th diaphragm ROf l 0tc9/
In this case, the loss factor peak on the low frequency side (1 (approximately MHz range) is slightly lower,
On the high frequency side, loss factor peak compensation (approximately 12Hz14)
is relatively high, but the above-mentioned JP-A-58-727
The one in Publication No. 41 (it is a smooth curve compared to ln. Therefore, the loss factor (t, an δ) in the range of engine shake is covered between both peak values and near both peak values. The value i is uniformly set to a large value n.As a result, the number of eye movements of the engine shake is 11.
．． 82, it is efficiently damped.

In addition, the characteristic 1fl + shore, the expansion elasticity of the first diaphragm 29, i, '? 20Q/m, second diaphragm any2
, nkg/nVc. In this case, conversely to the above, the loss factor peak Iff on the low frequency side (approximately 5 Hz
On the -frequency side, the loss factor peak (approximately 12 Hz range) is slightly lower, but the curve is relatively smooth as in the previous case. Therefore, the loss factor (ta) on the low frequency side is different from the case of the above characteristic i11.
Although n ) f[ is different, the loss factor in the positive number range of the engine shake covered between the peak values of the five peaks and in the vicinity of the peaks 11 becomes uniformly large.

Incidentally, even in the above case, the diameter i' of the first oriice;
[3.6φ positive, length is 10mm, diameter of second orifice is 4
The length is set to 160 words.

On the other hand, in the medium and high frequency range, for example RO ~ 2 h OHZ, 0
, l When the part width is less than IIS, a1 The partition plate 88 slightly moves up and down (maximum movement of about 0.44), so the dynamic spring constant is about 1 compared to the conventional model (2), as shown by characteristic I in Fig. 4.
It is sufficiently suppressed down to around 0Hz. As a result, together with the vibration absorbing effect of the rubber body 24, the impression of medium and high wave number components is effectively attenuated.

FIG. 5 shows a second embodiment of the present invention, and in this embodiment, the circular partition plate 48 provided at the interval 927 is formed in a portion other than the position where the first orifice 84 is formed. Furthermore, when the outer peripheral edge 4Ha is vertically movably fixed near the circular hole 27a of the partition wall 27 through an annular rubber support 41, the upper parts of the partition wall 27 and the annular plate 28 are The 7-rank parts 27b and 28h are designed to limit the vertical movable range to a maximum of 04 degrees. By the way, in this embodiment as well, the same effects and effects as those in the culvert embodiment, especially the effect of suppressing the dynamic spring constant by the partition plate 4B, can be obtained.
1. Can sufficiently attenuate medium and high frequency imaging.

Incidentally, in each of the above embodiments, the main movement frequency region of engine shake is mainly discussed. We have explained the case of damping, but what about other vibration objects? It is also possible to use C to attenuate. It is also possible to apply the invention to a motion damping body, such as a bushing for a suspension.

Effects of the Invention As is clear from the above explanation, the liquid-filled antisensor of the present invention allows the loss factor beak value to be set at a high level without affecting the i and s orifices, and Loss factor beak if obtained from each orifice
k l@ can be made equal. Therefore, a high loss factor 1ift can be obtained over a wide range1, and as a result, it is possible to obtain a very wide dynamical damping region (r) with one armor body. Since the vibration can be suppressed, the vehicle body tension aV in the medium and high frequency ranges can be sufficiently reduced in combination with the impact absorption effect of the elastic body.

Further, in this invention, a plurality of diaphragm chambers are integrally formed with predetermined diaphragm valves, so the structure of the body is extremely simple, and quality control is facilitated. CVc again. The reduction in the number of manufacturing steps leads to improved manufacturing efficiency and lower costs.

[Brief explanation of drawings]

Is Figure 1 the first embodiment of this invention? The cross-sectional view shown in Figure 2 is a model diagram of O's invention, and Figure 8 is the mode of each Hashiro loss filter that was obtained through experiments based on this model. FIG. 4 is a comparison diagram showing the dynamic spring characteristics of an embodiment of the present invention and a conventional liquid-filled fence; FIG.
Example? FIG. 6 is a sectional view showing a liquid-filled vibration isolator according to the prior application. 21... Liquid-filled anti-sensor body, 24... Rubber body (elastic body), 26... Liquid chamber, 27... Partition wall, 29... First diaphragm (predetermined diaphragm), 8o...・Second
Diaphragm A,) 11...first diaphragm chamber,! (
2... Second diaphragm chamber, 88... Partition plate, 84
...First orifice% 85...Second orifice. 2 people outside

Claims (1)

[Claims] (1) A liquid chamber surrounded by an elastic body communicates with each diaphragm chamber dedicated to the orifice through a plurality of orifices having different peak frequencies of loss factors, and the diaphragm expansion elasticity of each diaphragm chamber is set higher as the loss factor peak frequency of the corresponding orifice is larger, wherein each of the diaphragm chambers is integrally formed with a polymer through the predetermined diaphragm, and the liquid A liquid-filled vibration isolator characterized in that a partition plate defining the upper part of the diaphragm chamber on the chamber side and in which the dedicated orifice is formed is provided so as to be able to move slightly in the axial direction of the diaphragm chamber.