JPS6262033A - Vibro-isolating device - Google Patents

Abstract

PURPOSE:To damp low frequency large amplitude vibration while isolate high frequency small amplitude vibration, by arranging an elastic member between two frame members connected with different members and providing a partitioning wall, which has a built-in air chamber partitioned by an elastic film, in an enclosed chamber partitioned by the elastic member. CONSTITUTION:A hollow elastic member 3 of almost truncated cone shape is provided interposing between a frame member 1, comprising a dish-shaped member 5 and a cylindrical member 6, and a frame member 2 formed by securing a cup-shaped member 9 to the bottom surface of a flat plate 8. An enclosed chamber 11 is partitioned between said elastic member 3 and a diaphragm 10, held between the dish-shaped member 5 of the frame member 1 and its cylindrical member 6, and the inside of the enclosed chamber 11 is further divided into two fluid chambers 13, 14 by a partitioning wall 12. The partitioning wall 12 is formed into construction such that an air chamber 19 is partitioned by coating a bottom partition 16, having in its central part an upward facing hollow, with a hat-shaped upper partition 17 while by enclosing the upward facing hollow of the bottom partition 16 by an elastic film 18, and the both fluid chambers 13, 14 communicate through a throttle passage 15 between the both partitions 16, 17.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to automobiles and other vehicles, mechanical equipment, etc., and provides sufficient attenuation of low-frequency, large-amplitude vibrations, as well as advantageous insulation of high-frequency, small-amplitude vibrations. The present invention relates to a vibration isolating device that provides the following.

(Prior Art) For example, in a conventionally known vibration isolator that is widely used as an engine mount for automobiles, between a frame body connected to the vehicle body and a frame body connected to the engine,
An elastic member that contributes to the formation of a sealed chamber is arranged, and water or other liquid is sealed in the sealed chamber, and this sealed chamber is divided into two liquid chambers by a partition wall whose peripheral edge is fixed to one frame. Some liquid chambers are divided, and further, these two liquid chambers are made to communicate with each other through a passage provided in a partition wall.

The anti-vibration device is designed to prevent vibrations from occurring when vibration from the engine is input to the device, in addition to the internal friction of the elastic member, when the liquid in one liquid chamber flows into the other liquid chamber through the passage. , the flow resistance that the liquid experiences from the passage can provide vibration damping.

However, this vibration isolator is designed to prevent vibrations input into it from
For example, in the case of high-frequency, small-amplitude vibrations of 50 Hz or more, the interlocking passages between the two liquid chambers become blocked, increasing the dynamic spring constant of the device, which impairs the ride comfort of the vehicle. was there.

Therefore, a vibration isolator proposed to solve this problem is disclosed in Japanese Patent Application Laid-open No. 53-5376 (Japanese Patent Application No. 52-78).
No. 477) discloses a method in which a diaphragm is arranged at the boundary between both liquid chambers, and the diaphragm is vibrated in the liquid when high-frequency, small-amplitude vibration is input to the vibration isolator. This provides vibration absorption.

(Problem to be solved by the invention) However, in this device, since the diaphragm absorbs high-frequency vibrations by its vibration in the liquid, the frictional force between the diaphragm and the liquid, and the diaphragm A state in which the diaphragm cannot vibrate due to the inertial force of the liquid that should be eliminated during vibration, in other words, a rapid increase in the dynamic spring constant occurs at relatively low frequencies in the high frequency band, for example 150 to 2'0
There was a problem that it occurred at 0 Hz.

(Means for Solving the Problems) Against the background of the above-mentioned current situation, the present invention provides a preventive device that can extremely effectively exhibit the contradictory characteristics of attenuating low-frequency, large-amplitude vibrations and insulating high-frequency, small-amplitude vibrations. The present invention provides a shaking device.

Here, this invention disposes an elastic member that is in close contact with two frame members that contribute to forming a sealed chamber between two frame members that are respectively connected to different members, and also seals water or other liquid in the sealed chamber. Then, this sealed chamber is divided into two liquid chambers by a partition wall whose peripheral edge is fixed to one frame,
In a vibration isolator in which both of these liquid chambers are communicated by at least a passage provided in a partition wall or the like, a gas chamber independent from both liquid chambers is formed in the partition wall, and at least one of the gas chambers is connected to the liquid chamber. A portion adjacent to the liquid chamber is completely or partially partitioned by a flexible membrane.

(Function) In this vibration isolator, when low-frequency, large-amplitude vibrations are applied to the vibration isolator, the vibration is mainly caused by the flow resistance that the liquid in the liquid chamber receives as it flows through the passage. Effective damping of vibrations is provided, and in the case of high-frequency, small-amplitude vibrations caused by human forces, the deformation of the flexible membrane due to changes in the fluid chamber pressure provides sufficient isolation of the vibrations.

In addition, this deformation of the flexible membrane body causes expansion and contraction deformation of the gas chamber, and the frictional force between the flexible membrane body and the fluid and the inertia of the fluid to be eliminated during the deformation of the flexible membrane body. Since the forces are extremely small, isolation of high-frequency vibrations based on the deformation of the flexible membrane is possible up to considerably higher frequencies, for example vibrations of 200 to 2501 (z), compared to the prior art.

(Example) The present invention will be explained below based on illustrated examples.

In the figure, 1 indicates one member, for example a frame connected to an automobile body, 2 indicates the other member, for example a frame connected to an engine, and 3 indicates both of these frames 1.
2 shows an elastic member disposed in close contact therewith, which contributes to the formation of a sealed chamber, which will be described later.

Here, one frame 1 is constructed by fixing a lower end flange 6a of a cylindrical member 6 to a flange 5a of a dish-shaped member 5 with a mounting bolt 4 projecting downward from the center of the lower surface, and the other The frame body 2 is attached to the lower surface of a flat plate 8 provided with a mounting bolt 7 projecting upward from the center of the upper surface.
It is constructed by fixing the cup-shaped member 9.

Further, here, the elastic member 3, which can be made of rubber or a rubber-like elastic material, is formed into a hollow substantially truncated conical shape, and its lower end surface is connected to the upper end enlarged portion 6b of the cylindrical member 6, and the upper end thereof is The elastic member 3 is brought into close contact with the frames 1 and 2 by adhering the end faces to the circumferential surface of the cup-shaped member 9 by vulcanization or other means.

Here, the bendable elastic member 3 includes a cylindrical member 6 of the frame 1, a cup-shaped member 9 of the frame 2, and a peripheral portion between the dish-shaped member 5 of the frame 1 and the cylindrical member 6. Together with the clamped diaphragm 10, it contributes to the shape of the sealed chamber, and in the illustrated example,
In the entire sealed chamber 11 defined by these members,
Enclose water or other liquid.

In this example, such a sealed chamber 11 containing a liquid is also separated between two liquids by a partition wall 12 whose periphery is clamped liquid-tight between the dish-like member 5 and the cylindrical member 6. Divided into chambers 13.14, both of these chambers 13.14
are made to communicate with each other by opening a throttle passage 15 provided in the partition wall 12 to each of them.

Note that the throttle passage opening into both liquid chambers 13 and 14 is
It can also be formed at a position inside or outside the sealed chamber 11, independent of the partition wall 12.

The partition wall 12 here is constructed by covering a lower corner wall 16 made of synthetic resin or metal with an upward depression in the center and an upper partition wall 17 also made of synthetic resin or metal having a hollowed-out shape. Flange 16 of bulkhead 16.17
a, 17a are liquid-tightly clamped between the dish-shaped member 5 and the cylindrical member 6, and the respective liquid chambers 13, 14 is formed, and the upward recess of the lower corner wall 16 is further sealed with an elastic membrane 18, which is an example of a flexible membrane, to form an air chamber 19, which is an example of a gas chamber. Here, this elastic membrane body 18 is firmly fixed by embedding its peripheral portion downward into the lower corner wall 16 and sandwiching it between both partition walls 16 and 17,
Further, this elastic membrane 18 is placed adjacent to the upper liquid chamber 13 via an opening provided in the center of the upper partition wall 17 .

More preferably, in such a partition wall 12, by embedding a reinforcing layer 18a in the elastic membrane 18 and providing a deformation restraint plate 19a having a large number of holes in the air chamber 19, especially large amplitude vibrations can be suppressed. When you enter
This effectively prevents the elastic membrane 18 from being excessively deformed in the direction of bulging toward the liquid chamber 13 and in the opposite direction.

In the illustrated example, the throttle passage 15, which has an arcuate cross-sectional shape, is connected to the liquid chamber 13.1 at a diametrically opposed position.
The positions of these openings are as follows.
Of course, it can be selected as appropriate depending on the required extension length of the throttle passage 15.

When using the vibration isolating device configured in this way as an engine mount, the frame 1 is attached to the automobile body.
The frame body 2 is also connected to the engine via respective mounting bolts 4.7.

Here, the vibrations input to the frame body 2 from the engine (not shown) are somewhat attenuated by the internal friction of the elastic member 3, and when the vibrations are particularly low frequency and large amplitude vibrations, the vibrations input to the frame body 2 from the engine (not shown) are damped to some extent. Due to the alternating increase and decrease in the internal pressure of the liquid chambers, the liquid in the liquid chambers flows from one liquid chamber to the other liquid chamber through the throttle passage 15. Therefore, the kinetic energy of the liquid is absorbed by the constriction passage 15, resulting in effective damping of low-frequency, large-amplitude vibrations.

Note that when the liquid in the liquid chamber flows in this manner, the liquid chamber 13
The liquid flowing into the liquid chamber 14 from the diaphragm 10 increases the volume of the liquid chamber 14 by an amount corresponding to the volume reduction of the liquid chamber 13, for example, due to the elastic deformation of the diaphragm 10. In addition, if a through hole is provided to provide communication between the inside and outside of the diaphragm, the back pressure acting on the diaphragm 10 will be reduced, and the liquid will flow more smoothly. Furthermore, during such flow of the liquid, the elastic membrane 18 is of course deformed to the limit position in the direction of the liquid chamber 13 or in the opposite direction.

On the other hand, if the vibration input from the engine to the frame body 2 is a high frequency and small amplitude vibration, the throttle passage 15
However, since the elastic membrane 18 that contributes to defining the air chamber 19 deforms in either direction in response to internal pressure fluctuations in the liquid chamber 13, the internal pressure in the liquid chamber 13 decreases. Relative vibration of the frame body 2 with respect to the frame body 1 without causing an increase or decrease in the amount is sufficiently allowed. Therefore, here, without increasing the dynamic spring constant of the vibration isolator,
This results in sufficient insulation of high-frequency vibrations from the vehicle body. .

In addition, the elastic membrane 18 here causes the air chamber 19 to expand and contract when it deforms, so it is necessary to eliminate the inertial force of the fluid during its deformation, and the influence of the frictional force between it and the fluid during its deformation. can be almost removed,
Therefore, the vibration frequency at which the elastic membrane 18 cannot be deformed can be significantly increased compared to the prior art. In other words, even if the diameter of the deformable portion of the elastic membrane 18 shown in this example is the same as the diameter of the diaphragm disclosed in JP-A-53-5376, the elastic membrane 18 can exhibit a much better vibration absorption function.

FIG. 2 is a longitudinal sectional view showing another embodiment of the partition wall, and the partition wall 12 shown in FIG. 18, and the cylindrical molded part 18b of this elastic membrane 18 is airtightly fixed to the circumferential surface of the lower partition wall 160 with a caulking ring 20, thereby defining an air chamber 19. A hat wiping upper partition wall 17 similar to that described in FIG. It is something.

This partition wall 12 can be attached to the frame 1 by the flange 17a of the upper corner wall 17, and the elastic membrane 18 here can be inserted into the air chamber 19 when it is deformed in the direction of reducing the size of the air chamber 19. It locally protrudes inside the air chamber 19 through a hole in the deformable restraining plate 19a that is provided and comes into contact with the inner surface of the elastic membrane 18, as shown exaggerated in phantom lines in the figure.

Further, the partition wall 12 shown in FIG. 2(b) has a plurality of deformation restraining protrusions 16b having a comb-tooth cross-sectional shape projecting upward from the bottom wall of the central recess 161 of the lower partition wall 16, and An air chamber is formed by fixing a hat-shaped upper corner wall 17 to the outside of the lower partition wall 16 and adhering the periphery of the elastic membrane 18 to the central opening provided in the upper corner wall 17 by vulcanization or other means. 19 and a throttle passage 15, and the partition wall 12 shown in FIG. 2(C) has a lower partition wall 16 and a deformable restriction plate 19a, which are substantially similar to those shown in FIG. By fixing an upper corner wall 17 substantially similar to that shown in FIG. 2(6), and adhering an elastic membrane 18 to this upper corner wall 17, also in the same manner as described with respect to FIG. 2(b). , an air chamber 19 and a throttle passage 15 are formed.

Any of these partition walls 12 shown in FIG. 2 may function similarly to the partition walls 12 described with respect to FIG.
Effective damping of low-frequency, large-amplitude vibrations as well as sufficient isolation of high-frequency, small-amplitude vibrations can be provided.

Figure 3 shows the procedure for manufacturing a partition wall using sheet metal material, which functions similarly to the partition wall described above but has a structure that is somewhat different from that described above. 21 indicates an inner cylinder, and 22 indicates an outer cylinder.

Here, these inner and outer cylinders 21 and 22, which are overlapped and connected to each other, are provided with a flange 21 that protrudes radially outward.
a, 22a, respectively, and at the lower end of the cylindrical portion of the outer cylinder 22, as shown in FIG.
1, and a throttle passage 15 is formed between the inner circumferential surface of the enlarged diameter portion 22b and the outer circumferential surface of the inner cylinder 21.

Here, the throttle passage 15 is connected to the liquid chamber 13.14 at its respective end portion through openings 22C and 21b provided in the enlarged diameter top wall of the outer cylinder 22 and in the flange 21a of the inner cylinder 21, respectively. It goes through.

Moreover, the mutual connection of the inner and outer cylinders 21 and 22 here is as follows:
For example, it is possible to do this by spot welding the flanges 21a, 22a or their cylindrical parts, but as shown in FIG. 22
Protrusions 22d are provided at predetermined intervals in the circumferential direction on the flange 21a, and holes 2IC into which the protrusions 22d are fitted are provided on the other flange 21a, and after they are fitted together, the tips of the protrusions 22d are formed. This can also be done by caulking the parts, and in this case, the cost of joining the inner and outer cylinders 21, 22 can be reduced compared to the former case.

Further, in the illustrated example, a cup-shaped member 2J that contributes to the formation of an air chamber is provided at the upper end portions of these inner and outer cylinders 21 and 22.
The body part of the cup-shaped member 23 is fixed by spot welding, and then the deformation restraining plate 19a and the ring 24 having the elastic membrane 18 adhered to the center part are caulked and fixed to the upper end part of the cup-shaped member 23. The air chamber 19 is formed by the shaped member 23 and the ring 24 provided with the elastic membrane 18.

When the partition wall 12 is manufactured in this manner, the necessary components of the partition wall 12, and thus the partition wall, can be manufactured extremely easily and at low cost.

FIG. 4 is a diagram showing another embodiment of the present invention. In this example, the partition wall 12 fixed together with the diaphragm 10 between the dish-shaped member 5 and the cylindrical member 6 of the frame 1 is reinforced. It consists of a lower corner wall 16 made of a plastic plate and a lower corner wall 17 made of an elastic plastic plate fixed to the outside of the partition wall 16.

Here, the lower corner wall 17 having a hollow-hat shape has a cylindrical portion 17b at its center, and the top of this cylindrical portion 17b is connected to the top plate 17.
c. And this top plate 17c has a lower corner wall X6
is fixed. As shown in FIG. 4, the lower corner wall 16 has a cylindrical portion 16c on its outer periphery, and is fixed to the inner periphery of a cylindrical portion 17b.

A groove 16e having a substantially L-shaped cross section perpendicular to the circumferential direction is formed at the connection portion between the top plate 16d and the cylinder portion 16C of the lower corner wall 16, and a groove 16e is formed between the lower corner wall 17 and the throttle passage 15.
It consists of The throttle passage 15 has a C-shaped cross section, and one end in the longitudinal direction is inserted through a circular hole 17d formed in the top plate 17c of the lower corner wall 17, and the other end is connected to the groove 16e. The liquid chambers 13 and 14 are communicated through circular holes 16f formed in the respective liquid chambers 13 and 14.

Here, the top plate 17c of the lower corner wall 17 has a substantially spherical recess 17e on the lower surface, the internal pressure of the top plate 17C gradually decreases toward the axial center, and an air chamber 19 is formed between the top plate 17c and the top plate 16d of the lower corner wall 16. are doing.

In this embodiment, the lower corner wall 17 is made of an elastic plastic plate, and the lower corner wall plate 16 is made of a reinforced plastic plate, so that when the internal pressure of the liquid chamber 13 increases, the top plate 17
c can be deflected and deformed in a direction that reduces the air chamber 19.

Therefore, if the vibration applied manually from the engine to the vibration isolator is at a relatively low frequency, for example less than 53Hz,
The liquid chamber 13 that receives vibrations from the engine expands and contracts, and liquid flows into the liquid chamber 14 through the restriction passage 1i$15. For this reason,
Low frequency vibrations are absorbed by the resistance force generated within the throttle passage 15.

Further, when the vibration of the engine is high frequency, the throttle passage 15 is in a closed state. Therefore, when the pressure in the liquid chamber 13 increases, the dynamic spring constant increases and engine vibrations are directly transmitted to the vehicle body. However, in this embodiment, an air chamber 19 is provided, and the top plate 17c can be deformed to expand and contract the air chamber 19. Therefore, the liquid chamber 13 can change its volume, suppressing pressure rise, and thereby absorbing vibrations. be done.

In particular, when the lower corner wall 17 and the lower corner wall 16 are integrally constructed as in this embodiment, the space in the liquid chamber can be used effectively, and the ratio of the maximum diameter of the air chamber 19 to the inner diameter of the liquid chamber (opening ratio) can be increased to enable effective vibration absorption.

FIG. 5 shows a vibration isolator according to still another embodiment of the invention. In this embodiment, the top plate 17 of the previous embodiment is
In addition to the recess 17e of c, a recess 16g is also formed in the top plate 16d of the lower corner wall 16, and these recesses 16g.

An air chamber 19 is formed under the cooperation of 17e.

Further, in the embodiment shown in FIG. 6, the air chamber 19 is formed by making the central portion of the top plate 17c having a constant thickness convex upward, and forming a concave portion 17f on the inner surface.

Furthermore, in this embodiment, a spiral groove 16h is provided around the lower corner wall 16 as shown in FIG. It is now possible to do so.

(Effects of the Invention) Thus, the vibration isolating device of the present invention can be applied to automobiles and other vehicles, mechanical equipment, etc. to provide sufficient attenuation of low frequency, large amplitude vibrations, and can also provide sufficient attenuation of high frequency, small amplitude vibrations. can be effectively isolated up to a fairly high frequency range.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Figs. 2(a) to (C) are sectional views showing modified examples of the partition wall, and Fig. 3 illustrates the manufacturing procedure of the partition wall. Figure 4(a)
, Ltd. are respectively a longitudinal cross-sectional view and a perspective view showing a partition wall constituent member of another embodiment of the present invention, FIG. 5 is a longitudinal cross-sectional view of yet another embodiment of the present invention, and FIG. FIGS. 2A and 2B are a sectional view showing still another embodiment of the partition wall and a perspective view showing its constituent members, respectively. 1.2... Frame body 3... Elastic member 11...
・Closed room 12...Partition walls 13, 14...
・Liquid chamber 15... Throttle passage 19... Air chamber 18... Elastic membrane Patent applicant Brideston Co., Ltd. Figure 3 (b) (C) Water Figure 4 (a) Figure 5

Claims (1)

[Claims] 1. Two frames each connected to different members;
An elastic member placed between these two frames contributes to the formation of a sealed chamber, a liquid sealed in the sealed chamber, and a peripheral portion fixed to one of the frames to divide the sealed chamber into two liquid chambers. A vibration isolator comprising a partition wall and a passage that brings communication between the liquid chambers, wherein a gas chamber independent from both liquid chambers is formed in the partition wall, and at least one of the gas chambers is connected to the liquid chamber. A vibration isolating device characterized in that an adjacent portion of the is partitioned by a flexible membrane.