JPH0237497B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a liquid-filled power unit mounting device.

(Prior Art) As a conventional fluid-filled power unit mounting device, there is one shown in FIG. 1, for example (Japanese Patent Application Laid-open No. 72740/1983). That is, a mount rubber 53 having an internal space 53a filled with fluid is fixed between a power unit side substrate 51 and a vehicle body side substrate 52, and a diaphragm 54 and a partition plate 55 are attached to one substrate 52 side. So, diaphragm 5
4 and the partition plate 55, a fluid chamber 57 is formed between the partition plate 55 and the other substrate 51, and a fluid is sealed in the sub chamber 56 and the fluid chamber 57. and an orifice 60 is provided in the partition plate 55, and the orifice 60 connects the fluid chamber 57 and the sub-chamber 5.
6 are communicated with each other.

As shown in FIG.
0, it is possible to obtain high damping force, and
As shown in Figure b, the dynamic spring constant value of the mount device can be reduced in a frequency range lower than the resonance frequency f ₀ . Furthermore, a partition plate 55 whose periphery is elastically supported to the substrate 52 by a mount rubber 53 constitutes a valve mechanism that is movable against high frequency micro vibrations and restrained from moving against low frequency large amplitude vibrations. , it is possible to reduce the dynamic spring constant value of the mount device in a predetermined high frequency range.

However, in such a conventional mounting device, the orifice 60 is separated from the plate-shaped partition plate 55.
Because of this structure, the range in which good dynamic spring constant values can be obtained is relatively narrow in the low frequency range, for example 6 to 40 Hz, and the problem is that good vibration transmission characteristics cannot be obtained. It was hot.

(Object of the Invention) This invention was made in view of the above-mentioned conventional problems, and it forms an elastically deformable intermediate chamber in the partition plate, and connects a plurality of orifices in series through the intermediate chamber. In addition, by providing the partition plate with a valve mechanism that is movable against high-frequency micro vibrations and restrained from moving against low-frequency large-amplitude vibrations, the practical frequency range of the engine, for example, 0 to 0.
The purpose is to provide a good dynamic spring constant value at 400Hz and solve the above problems.

(Embodiments) The present invention will be described below with reference to illustrated embodiments.

FIG. 3 shows an embodiment of the present invention. A mount rubber 4 having an internal space 3 is vulcanized and bonded between the power unit side substrate 1 and the vehicle body side substrate 2, and the partition plate 5 and the diaphragm 6 are connected to each other with the diaphragm 6 on the outside. The peripheral edges are overlapped and clamped between the substrate 1 and the cover 7, and fixed with rivets 8. 21 is a push ring,
To prevent the mount rubber 4 from swelling when contracted.

The partition plate 5 has an intermediate chamber 19 defined by an upper plate 19a, a lower plate 19b, and a side plate 19c connecting both plates 19a and 19b, and at least a part of the side plate 19c is made of rubber or elastomer. The intermediate chamber 19 is made of a soft elastic body 19d so as to be elastically deformable.

Furthermore, the partition plate 5 includes a first valve mechanism 9 and a second valve mechanism 12 that are movable against high-frequency minute vibrations and restrained from moving against low-frequency large-amplitude vibrations.
A first orifice 13 and a second orifice 14 each having a resonant frequency in a low frequency range are connected in series. The first valve mechanism 9 is provided on an upper plate 19a, and is loosely fitted between an annular portion 10 having a U-shaped cross section whose two opposing sides form a pair of stoppers 10a and 10b, and the stoppers 10a and 10b,
It consists of a movable plate 11 that is movable between both stoppers 10a and 10b. The second valve mechanism 12 includes a lower plate 1
9b, the annular portion 15 has a U-shaped cross section and has two opposing sides forming a pair of stoppers 15a, 15b.
and a movable plate 16 that is loosely fitted between the stoppers 15a and 15b and is movable between the stoppers 15a and 15b.
It becomes more. Then, the resonance frequency of the first valve mechanism 9 is set to a high frequency around 60 to 170 Hz, which causes muffled noise, and the dynamic spring constant value of the mount device in the range of 60 to 170 Hz is reduced. Then, the high frequency range higher than that, for example 250
At ~300 Hz, the first valve mechanism 9 exceeds the resonance point and does not function well, resulting in a deterioration region where the dynamic spring constant value as a mount device increases, and high-frequency micro-vibrations due to engine combustion are transmitted to the vehicle body. Therefore, the resonance frequency of the second valve mechanism 12 is set to 250~
Set to a high frequency around 300Hz, lower the dynamic spring constant value as a mount device in the range of 250 to 300Hz, and combine the first valve mechanism 9 and the second valve mechanism 12 to achieve a high frequency range of, for example, 60 to 400Hz. In this method, the dynamic spring constant value of the mounting device is set appropriately.

The first orifice 13 is provided on the upper plate 19a,
For example, 6
Give a resonance frequency of ~15Hz to obtain high damping force. Then, the low frequency range slightly higher than that,
i.e. engine idle vibration range e.g. 20~30Hz
In this case, the dynamic spring constant value of the mounting device increases, and engine idle vibrations are transmitted to the vehicle body. Therefore, for example, a slightly higher low frequency
The resonance frequency of the second orifice 14 is set to 40 Hz, and the dynamic spring constant value of the mount device in the engine idle vibration range is reduced.

Note that the resonance frequency at which the damping capacity of the orifices 13 and 14 reaches its maximum value depends on the equivalent mass of the fluid in the orifices 13 and 14 and the diameter of the orifices 13 and 14, and the larger the mass, the lower the resonance frequency. The smaller the diameter, the lower the resonance frequency. Further, it has been found through various experiments conducted by the present inventor that the larger the diameter, the greater the damping ability.

It has also been found that the larger the cross-sectional area of the valve mechanisms 9, 12, the higher the resonance frequency, and the shorter the distance between the stoppers 10a, 10b, 15a, 15b, the higher the resonance frequency.

Next, the operation will be explained with reference to FIGS. 4 to 6.

Low frequency range that causes engine shake, e.g. 6
When a large amplitude vibration of ~15Hz is input from the board 1,
The mount rubber 4 expands and contracts significantly, causing a change in the volume of the fluid chamber 17. As a result, the second valve mechanism 1
The second movable plate 16 is locked to the stopper 15a or 15b and its movement is restricted, and the fluid mass in the first orifice 13 resonates at the resonance frequency _f1 to generate a large damping force and suppress this vibration. (See Figure 4).

When large amplitude vibrations in the low frequency range, for example 20 to 30 Hz, generated by engine idle vibration are input from the board 1, the first valve mechanism 9 and the second valve mechanism 1
Each movable plate 11, 16 of 2 is a stopper 10a, 15
a, 10b, 15b and is restrained from moving, and the frequency is slightly lower than the resonance frequency _f2 of the second orifice 14, so the dynamic spring constant value of the mounting device is reduced, and this vibration transmission to the vehicle body (see Figure 5).

In this way, it is possible to give individual resonance frequencies f ₁ and f ₂ to the first orifice 13 and the second orifice 14 by making a part of the side plate 19c of the intermediate chamber 19 into which both the orifices 13 and 14 open relatively soft. This is because the intermediate chamber 19 has a structure that can be elastically deformed by forming the elastic body 19d, and this intermediate chamber 19 also has a slight influence on the throttle characteristics of both orifices 13 and 14.

High frequency range that causes muffled sound, e.g. 60-170Hz
When a small _- amplitude vibration of The fluid cannot flow through the first orifice 13, which has a lower resonance frequency than the second orifice 14, and the fluid chamber 1
7 and intermediate chamber 19. In this case, the mount rubber 4 expands and contracts, and the first valve mechanism 9 with the resonance frequency _f3 mainly acts.
That is, the movable plate 11 is moved to the stoppers 10a, 10b.
The dynamic spring constant value of the mount device is maintained approximately constant by moving between the two, thereby reducing the transmission of small-amplitude vibrations to the vehicle body in the high frequency range of 60 to 170 Hz (see Fig. 6).

To explain in more detail, the first orifice 13 provides a high damping effect in the low frequency range that causes engine shake, for example 6 to 15 Hz, so the static spring constant value of the mount rubber 4 can be adjusted to a mount device consisting of a single mount rubber. This makes it possible to reduce the dynamic spring constant value in the low frequency range where engine idling vibration occurs in conjunction with the action of the second orifice 14, and also allows the fusion of both valve mechanisms 9 and 12. Coupled with this effect, the dynamic spring constant value of the mount device can be maintained substantially constant in a high frequency range that causes muffled noise, for example, 60 to 170 Hz.

In a high frequency range that is slightly higher than the high frequency range that causes muffled noise, for example, 250 to 300 Hz, in a worsening range where the dynamic spring constant value of the mount device increases, the main action of the second valve mechanism 12 with the resonance frequency f ₄ The deterioration of the dynamic spring constant value can be reduced in the shaded area in FIG.

In FIGS. 4 to 6, the solid line shows the characteristics of the mounting device according to an embodiment of the present invention, and the broken line shows the characteristics of the conventional mounting device including one orifice and one valve mechanism for high frequency. Also,
For comparison, the characteristics of a mounting device made of a single mount rubber are shown by a dashed line in FIG.

FIGS. 7 and 8 show a first orifice 113 and a second orifice 114, each having a resonant frequency in a low frequency range, and a second orifice 113 that is movable with respect to high frequency micro vibrations and whose movement is restrained with respect to low frequency large amplitude vibrations. Another structural example of the partition plate 105 including one valve mechanism 109 and a second valve mechanism 112 is shown.

The first valve mechanism 109 has an opening 105a in the partition plate 105, and a thin film-like flexible member 11 mainly made of rubber or elastomer and embedded with a fibrous member.
0 to the partition plate 105, and the flexible member 11
0 to cover the opening 105a, and the resonance frequency is set near the high frequency range that produces muffled sound. The first orifice 113 forms a fluid passage 113a with a relatively large volume around the opening 105a of the partition plate 105. One end of the passage 113a communicates with the outside through a constriction part 113b, and the other end communicates with the constriction part 113c. The resonant frequency is set in a low frequency range that causes engine shake. The intermediate chamber 119 has a rectangular tube-shaped relatively hard elastic body 1 between the partition plate 105 and the intermediate plate 115.
20 are glued together. Each support 121 is embedded in the elastic material 120, and maintains the distance between the partition plate 105 and the intermediate plate 115, and also supports the elastic material 120.
20 (see FIG. 9).

The second valve mechanism 112 has an opening 115a in an intermediate plate 115, and a thin film-like flexible member 12 mainly made of rubber or elastomer and embedded with a fibrous member.
2 to the intermediate plate 115, and the flexible member 12
2 to cover the opening 115a, and adjust the resonance frequency to a region where the dynamic spring constant value in the high frequency range is deteriorated, for example.
It is set to a high frequency around 250-300Hz. The second orifice 114 is an opening 115 in the intermediate plate 115.
A relatively large volume fluid passage 114a around a
, and one end of the passage 114a is connected to the constricted portion 114.
b communicates with the outside, and the other end communicates with the intermediate chamber 119 through a constriction part 114c, and the resonance frequency is set slightly higher than the low frequency range caused by engine idle vibration.

By incorporating this partition plate 105 into the mounting device in place of the partition plate 5 of the embodiment described above, the constriction part 113b of the first orifice 113 opens into the subchamber 18, and the constriction part 114b of the second orifice 114 opens into the fluid chamber. 17 to obtain the same effect as in the embodiment described above, the first orifice 113 and the second orifice 114 are opened in both constricted portions 113b, 113.
The constricted portion 113b,
Fluid passage 1 having a larger cross-sectional area than those of 113c, 114b, and 114c and having a relatively large volume
13a and 114a are interposed, even if the diameters of the aperture parts 113b, 113c, 114b, and 114c are relatively large, the frequency at which the attenuation ability shows the maximum value can be adjusted to a predetermined low frequency. Since the diameter can be set large, the damping ability can be increased. Further, since the outer surface of the elastic material 120 that defines the intermediate chamber 119 comes into contact with the fluid chamber 17 where the pressure fluctuation is large, the elastic material 120
Each orifice 113, 11 is relatively hard.
It is possible to provide 4 with individual resonant frequencies.

Note that the resonance frequency of both the valve mechanisms 109 and 112 can be set to a higher frequency side by increasing the rigidity of the flexible members 110 and 122.

Further, the gist of the present invention is to provide the mounting device with good characteristics in a low frequency range, and therefore the valve mechanism 9, 109, 12, 1
At least one 12 may be provided.

(Structure of the Invention) As explained above, according to the present invention, the structure is such that a mount rubber having an internal space is fixed between a board on the power unit side and a board on the vehicle body side, and A diaphragm and a partition plate are fixed to the substrate side, a sub-chamber is formed between the diaphragm and the partition plate, a fluid chamber is formed between the partition plate and the other substrate, and the sub-chamber and the sub-chamber are formed. The partition plate has an intermediate chamber in which at least a part of the side surface in contact with the fluid chamber or the sub-chamber is partitioned by an elastic body, and in which the fluid is sealed; and a plurality of orifices that communicate the sub-chamber, the intermediate chamber, and the fluid chamber, and further includes a valve mechanism that is movable against high-frequency minute vibrations and restrained from moving against low-frequency large-amplitude vibrations, and , an orifice that communicates the intermediate chamber and the sub-chamber,
The resonant frequency is set to a low frequency range that causes engine shake, and the orifice that communicates the intermediate chamber and the fluid chamber is a fluid-filled power unit whose resonant frequency is set to a low frequency range that is slightly higher than engine idle vibration. It was used as a mounting device.

(Effect of the invention) Therefore, the orifice provides a high damping force against low frequency, large amplitude vibrations that cause engine shake, and also provides a high damping force against low frequency, large amplitude vibrations caused by slightly higher engine idle vibrations. The dynamic spring constant value of the mount device is reduced to reduce the transmission of this vibration to the vehicle body, and the dynamic spring constant value of the mount device is reduced to reduce the transmission of this vibration to the vehicle body. It is possible to reduce the transmission of this vibration to the vehicle body by lowering the numerical value, and it is possible to provide a mount device that has good characteristics over a wide range of practical engine frequency ranges. More specifically, by providing an elastic body in the intermediate chamber filled with fluid, it becomes easy to set the resonance frequencies of a plurality of orifices arranged in series to different frequency ranges. Specifically, when setting appropriate different resonance frequencies for multiple orifices arranged in series, setting an appropriate resonance frequency for one orifice in the series will generally cause the other orifice to have an appropriate resonance. Unable to set frequency. This is because one orifice functions as a resistance with respect to the other orifice, and the internal pressure of the intermediate chamber filled with fluid cannot be varied. In contrast, in the present invention, an elastic body is provided in the intermediate chamber to make the volume of the intermediate chamber filled with fluid variable, so that when one orifice functions as a resistance, the internal pressure of the intermediate chamber cannot be changed. Therefore, it is possible to set an appropriate resonant frequency for each orifice.

In this way, a plurality of orifices given resonant frequencies in different low frequency ranges are provided on the partition plate so as to communicate the sub-chamber, the intermediate chamber and the fluid chamber, and the fluid chamber or the sub-chamber is At least a part of the side surfaces of the intermediate chambers in contact with each other are partitioned with an elastic body, and the volume of the intermediate chamber filled with liquid can be elastically varied.The multiple orifices prevent low-frequency waves that cause engine shake. A high damping force can be applied to large-amplitude vibrations, and the dynamic spring constant value of the mount device can be reduced in response to low-frequency, large-amplitude vibrations caused by slightly higher engine idling vibrations.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional fluid-filled power unit mount device, Fig. 2a is a diagram showing frequency-damping force characteristics, Fig. 2b is a diagram showing frequency-dynamic spring constant characteristics, and Fig. 2a is a diagram showing frequency-damping force characteristics. FIG. 3 is a cross-sectional view showing an embodiment of the present invention, FIG. 4 is a diagram showing frequency-damping force characteristics, FIGS. 5 and 6 are diagrams showing frequency-dynamic spring constant characteristics, and FIG. 7 is a diagram showing frequency-dynamic spring constant characteristics. The figure is a sectional view showing another example of the structure of the partition plate, and FIG.
9 is a perspective view of the elastic body. 1, 2: Substrate, 3: Internal space, 4: Mount rubber, 5, 105: Partition plate, 6: Diaphragm,
9,109: First valve mechanism (valve mechanism), 1
2,112: Second valve mechanism (valve mechanism), 1
3,113: First orifice (orifice), 1
4,114: Second orifice (orifice), 1
7: Fluid chamber, 18: Sub-chamber, 19, 119: Intermediate chamber, 19d, 120: Elastic body.

Claims (1)

[Claims] 1. Fix a mount rubber having an internal space between the power unit side board and the vehicle body side board, fix the diaphragm and the partition plate to either of the board sides, and connect the diaphragm and the partition plate. A sub-chamber is formed between the partition plate and the other substrate, a fluid chamber is formed between the partition plate and the other substrate, and a fluid is sealed in the sub-chamber and the fluid chamber. It has an intermediate chamber in which at least a part of the side surface in contact with the next chamber is partitioned by an elastic body and a fluid is sealed therein, and a plurality of orifices that communicate the intermediate chamber and the sub-chamber and the intermediate chamber and the fluid chamber. an orifice which communicates the intermediate chamber and the sub-chamber, further comprising a valve mechanism that is movable in response to high-frequency minute vibrations and restrained in its movement in response to low-frequency large-amplitude vibrations;
The resonant frequency is set in a low frequency range that causes engine shake, and the orifice that communicates the intermediate chamber and the fluid chamber has a resonant frequency set in a low frequency range that is slightly higher than engine idle vibration. Liquid-filled power unit mounting device.