JPS6018632A - Vibration isolator - Google Patents

Abstract

PURPOSE:To achieve wide range damping of vibration by providing a floating member for opening/closing a communication hole between the liquid separation chambers and absorbing the high frequency low amplitude vibration through motion of said member. CONSTITUTION:A vibration absorbing unit 28 arranged between liquid chambers 26A, 26B has upper and lower discs 32, 34 separated each other while floating rings 54, 56 having specific gravity same or lower than that of the liquid in the liquid chamber 26 are arranged between side discs. Since said members 54, 56 are movable up and down, pressure rise in the liquid chamber 26A is prevented through motion of said members 54, 56 under high frequency low amplitude vibration to absorb the vibration. Under low frequency high amplitude vibration, the floating members 54, 56 are pressed against the lower disc 34 to flow the liquid in the upper liquid chamber 26A through an orifice 44 arranged in the upper and lower discs 32, 34 into the lower liquid chamber 26B thus to produce the vibration isolating effect through the damping function.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a vibration isolator for reducing vibrations from a vibration source.

[Background Art] Vibration isolating devices, generally called vibration isolating rubber, are used, for example, in engine mounts of automobiles to absorb vibrations from the automobile engine and prevent them from being transmitted to the vehicle body.

Two vibration-damping liquid chambers are provided as this vibration isolator, and the vibration from the vibration source is transmitted as a contraction force to one of the liquid chambers, and when the liquid in this liquid chamber is moved to the other liquid chamber through the restriction passage. A configuration has been proposed that uses internal friction to absorb vibrations using a resistive force.

However, with this vibration isolator, the input vibration is, for example, 50
In the case of a high frequency of Hz or higher, the amplitude is small, the restriction passage becomes clogged, the internal pressure rises, and the spring constant becomes high. As a result, the transmission rate of vibration increases, causing a worsening of the ride comfort of the vehicle.

[Object of the Invention] Taking the above-mentioned main points into consideration, the object of the present invention is to obtain a vibration isolating device that can appropriately attenuate even high frequency vibrations and is capable of damping vibrations over a wide range.

[Summary of the invention] The vibration isolator according to the present invention is made of rubber or rubber-like elastic material.
A hollow chamber mainly formed from a hollow molded body that mainly absorbs vibrations is used as a liquid chamber, and these liquid chambers are separated from each other via a passage that restricts the flow of the liquid confined inside the chamber, and the liquid flow that occurs in this restriction passage. A vibration isolating device that uses a damping effect based on viscous resistance in combination with a vibration damping function mainly based on internal friction, which is the main vibration absorber, to buffer vibrations, and a vibration absorbing unit is provided facing at least one of the separated liquid chambers. , this vibration absorbing unit has a holding body and a buoyancy body attached to the holding body, and this buoyancy body blocks the communication hole between the holding body and the liquid chamber when the pressure of one liquid chamber increases, thereby suppressing low frequency waves. During vibration, vibrations are absorbed by the restricted passage, and the buoyant body has a specific gravity that is approximately equal to or lower than that of the liquid in the liquid chamber.During high-frequency vibrations, the pressure in the liquid chamber is reduced due to changes in the physical energy of the liquid chamber due to the deformation of this buoyant body. It is designed to limit the rise and obtain low movement and spring constant.

[Embodiment of the Invention] Fig. 1.2 shows a sectional view of a vibration isolator to which the present invention is applied. This vibration proof! Position A is used as an engine mount, and a mounting bolt 12 is fixed to the center of the bottom plate 10 for mounting to a vehicle body (not shown).

The lower end of a cylindrical connecting plate 14 is bent and caulked to the outer periphery of the bottom plate 10, and the periphery of a lower diaphragm 16 made of an elastic material is located between the bottom plate 10 and the connecting plate 14. The part is pinched. An air chamber 18 is formed between the center portion of the bottom plate 10 and the lower diaphragm 162, and the lower diaphragm 16 is movable in the expansion/contraction direction of the air chamber 18.

The outer periphery of the lower end of rubber 20, which is a hollow molded body whose axis is perpendicular, is vulcanized and bonded to the upper part of the connecting plate 14. It is also possible to use other elastic materials in place of the rubber 20.

A top plate 22 is fixed to the top of the rubber 20. A mounting bolt 24 is fixed to the center of the top plate 22 for mounting an engine (not shown).

The hollow chamber formed by the -Ilv 20 and the lower diaphragm 16 is a liquid chamber 26, and this liquid chamber 26 is filled with a liquid such as water.

A vibration absorbing unit 28 is arranged within the liquid chamber 26 . As shown in FIG. 2.3, this vibration absorbing unit 2B is attached to the bottom plate 10 by a cylindrical body 30 whose lower end is held between the lower diaphragm 16 and the rubber 20. The outer peripheries of the upper disk 32 and lower plate 34 are fixed inward. Thereby, the vibration absorption unit 28 separates the liquid chamber 26 into an upper liquid chamber 26A and a downstream chamber 26B.

A holding chamber 36 is formed between the upper disk 32 and the lower disk 34, and a circular hole 3 is provided in the center of the upper disk 32 and the lower disk 34.
B, 40 is drilled. A cylindrical body 42 is fixed after passing through these circular holes 38 and 40, and an orifice 44 passing through the axial center of this cylindrical body 42 is connected to the upstream chamber 28.
A and the downstream chamber 26B are connected to each other by a restricted passage.

As shown in detail in FIG. 2, the upper disk 32 and the lower disk 34 have a plurality of communicating holes 46 whose axes are arranged concentrically around the circular hole 38, 40 through which the cylindrical body 42 passes. .48 is drilled. These communication holes 46 and 48 are connected to the holding chamber 3.
6, the upper liquid chamber 26A and the downstream chamber 28B are communicated with each other.

Near the communication hole 46 formed in the lower disk 34, ring grooves 50.52 are formed on the surface facing the holding chamber 36, and a buoyant body 54.5 is inserted into these rings 11'1i50.52.
6 can be accommodated.

Each of these buoyant bodies 54 and 56 has a ring shape, and its specific gravity is equal to or lower than that of the liquid in the liquid chamber 26. That is, when water is injected into the liquid chamber 26, its specific gravity is about 1.0 or less.

In the vibration isolator of this embodiment configured in this way, the bottom plate l
O is fixed to the car body via the mounting pole) 12,
The installation is completed by mounting and fixing the automobile engine to the top plate 22 with the mounting bolts 24.6 When removing the engine, the weight of the engine acts on the port 24, so the pressure in the upper liquid chamber 26A increases. ”
- This pressure is applied to the liquid chamber 26 through the holding chamber 36.
B, and the air chamber 18 contracts. In this case, the buoyant bodies 54 and 56 can move up and down 11 times within the holding chamber 36, so the flow of the liquid is not obstructed.

When the engine is running, the vibrations generated by the engine are transmitted to the top plate 22.
transmitted via. The rubber 20 acts as a main vibration absorber, and can absorb vibrations by the vibration damping function based on the internal friction of the rubber 20. Furthermore, when the frequency of the vibration is low, the amplitude is large, so that the pressure 1 in the upper liquid chamber 26A is transmitted to the buoyant body 54.56, as shown in FIG. It is pressed into the bottom of the ring groove 50,52. Therefore, the -1-liquid chamber 26A and the upper liquid chamber 26B are communicated only through the orifice 44.

Therefore, the damping effect based on the viscous resistance of the liquid flow generated in the orifice 44 can improve the vibration damping effect.

Furthermore, if the engine vibration has a high frequency of, for example, 50 Hz or higher, the amplitude is small and the orifice 44 may become clogged. In this case, the buoyant bodies 54 and 56 in the vibration absorbing unit 28 receive a downward pressing force as shown in FIG. 3(B), causing a volume change in the upper liquid chamber 26A.
6A pressure upper layer is prevented and vibrations are absorbed.

In this way, in this embodiment, vibrations can be absorbed over a wide range of frequencies, and the ride comfort of the vehicle can be improved.

Next, FIG. 4 shows a second embodiment of the present invention. In this embodiment, an upper liquid chamber 26A and an upper liquid chamber 26B are provided as in the previous embodiment, and these are separated by a vibration absorbing unit 28 and communicated through an orifice 44. In this embodiment, the center portion of the bottom plate 10 is bent significantly downward to form a large air chamber 18. Further, the bottom plate 10 has a mounting bolt 12 protruding from near its periphery to be fixed to the vehicle body.

In addition, in this embodiment, the 14 connection plates of the previous embodiment are generally not cut, and a connection plate 58 is fixed onto the bottom plate 10, and between this connection plate 58 and the bottom plate 10, the And one cylindrical body 30 is held. On this connecting plate 58,

Rubber, which has a similar role to that of 20 to 1 Ift, is bonded.

Therefore, in this embodiment as well, the same effects as in the previous embodiment can be obtained.

Next, FIG. 5 shows a third embodiment of the present invention. In this embodiment, a lower inflator 16 is fixed to the lower part of a cylindrical body 60 which has a shape substantially the same as the connecting plate 14 of the first embodiment, and a vibration absorbing unit 28 is attached to the part between 11 of this cylindrical body 60. It is fixed l,%. The center portion of the lower tire phragm 16 is attached to the weight 16A to improve the frequency response. Further, a flange 62 having a central portion and a penetrator is fixed to the upper end of the cylindrical body 60, and a gob 20 (17 fixed) which is integral with the vibration absorber 2 is attached to the hook 2.

Therefore, in this embodiment, the space between the vibration absorbing unit 28 and the rubber 20 is the upper liquid chamber 26A, and the space between the vibration absorbing unit 28 and the lower Guiaphragm 16 is the upper liquid chamber 26B.

However, in this embodiment as well, the structure of the vibration absorbing unit 28 is the same as in each of the embodiments described above, so that similar effects can be obtained.

Next, FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, the internal structure of the vibration absorbing unit 28 is slightly different from those of the previous embodiments. That is, the upper disk 32 and the lower disk 3
4 are in close contact with each other, and four hemispherical portions are formed from the surfaces of this contact, and the corresponding four portions form a spherical holding chamber 64. These holding chambers 6
4 communicates with the upper liquid chamber 26A and the upper liquid chamber 26B through communication holes 46 and 48, respectively, as in the previous embodiment.

Further, in this embodiment, a buoyancy method 66, which is a modification of a buoyancy body, is housed in the holding chamber 64. This buoyancy method 66 is movable within the holding chamber 64 by using an outer diameter smaller than the inner diameter of the holding chamber 64, and its specific gravity is equal to or lower than the liquid in the liquid chamber as in each of the above embodiments. There is.

Therefore, in this embodiment as well, the buoyant ball 66 blocks the communication holes 46 and 48 during low frequency vibrations, allowing communication between the upper liquid chamber 26A and the lower liquid chamber 26B only through the orifice 44, and during high frequency vibrations, the buoyancy balls 66 vibrate due to volume changes in the liquid chambers. It is designed to absorb accurately.

Next, FIG. f57.8 shows a fifth embodiment of the present invention. In this embodiment, a 6-day disk is used in place of the upper disk 32, 34 of each of the above embodiments, and a circular communication hole 70 is bored in the center of the disk 68 to form the upstream chamber 26A. , communicates with the downstream chamber 26B. The axial center portion of this communication hole 70 has an enlarged inner diameter and has a holding chamber 72 .

A buoyant plate 74, which is a modified version of a buoyant body, is inserted into this holding chamber 72 and moves vertically and horizontally within the holding chamber 72.
It is now possible to move around the city. The ratio 1 (1) of this buoyancy plate 74 is equal to or greater than 1' to the liquid in the liquid chamber as in each of the above embodiments.

Further, as shown in FIG. 8, this disk 68 has a ring-shaped orifice 76 formed on the outer periphery of the axially intermediate portion. This orifice 76 has a notch 78 that communicates with the upper liquid chamber 26A at a part of the circumference and a notch 8 that communicates with the downstream chamber 26B at another part of the circumference.
o is formed. (1) The liquid in the upper liquid chamber 28A enters the orifice 76 through the disc 68
After turning half a turn, it passes through the notch 80 to reach the downstream chamber 26B, and an orifice with a long axis is obtained.

In this embodiment, the buoyancy plate 74 is pressed against the bottom surface of the holding chamber 72 due to the pressure R of the upper liquid chamber 26A and blocks the communication hole 70, and the upper liquid chamber 2
6A and the downstream chamber 26B, and when high frequency vibration occurs, the vibration is absorbed by the volume change of the liquid chamber due to the deformation of the buoyancy plate 74, as in the previous embodiment.

Next, FIG. 9 shows a sixth embodiment of the present invention. Also in this embodiment, a disk 68 is used to open the orifice 7.
6 is formed. Further, a communication hole 70 is formed in the center of the disc 68, and the upper liquid chamber 26A and the lower liquid chamber 26A are connected to each other. It communicates with the α chamber 26B.

However, in this embodiment, the holding chamber 72 is not formed in the communication hole 70, and a stopper pin 82 having an enlarged portion at its tip protrudes from the front and back surfaces of the disc 68. These stopper pins 82 pass through the buoyancy plate 84, and the buoyancy plate 84
can move toward and away from the disc 68 along the stopper pin 82. Further, a rubber collar 86 is fixed to the stopper pin 82 near the attachment portion to the disc 68, and is used for abutting the buoyancy plate 84.

The buoyancy plate 84 in this embodiment also has a specific gravity equal to or lower than that of the liquid in the liquid chamber, as in the previous embodiments.

In this embodiment configured in this way, when the buoyancy plate 84 is separated from the rubber stopper 86, liquid can flow from between the buoyancy plate 84 and the disc 68 through the communication hole 70. . However, when the pressure in the upper liquid chamber 26A increases during low frequency vibration, the buoyancy plate 84 in the upper liquid chamber 26A moves to the rubber stopper 8.
6, and when the pressure in the downstream chamber 26B increases, the downstream chamber 2
Since the buoyancy plate 84 in 6B is pressed against the rubber stopper 86, the communication hole 70 is closed and the two liquid chambers are communicated only through the orifice 76. Also, during high frequency vibration, the buoyancy plate 84
is pressed against the rubber stopper bar 86, and the vibration can be absorbed by the volume change.

Referring next to FIG. 1O, there is shown an f57 embodiment of the present invention. This embodiment has a structure f in which an orifice 76 is formed in the vibration absorbing unit of the fourth embodiment shown in FIG. That is, a floating ball 66 having a specific gravity equal to or lower than the specific gravity of the liquid is housed in the holding chamber 64, and this buoyant ball 66 opens and closes the communication hole 46.48, and the upper disk 32 A ring-shaped orifice 76 is formed on the outer periphery of .34, and a notch 78.
An orifice with a long axis is formed in communication with 6E. Therefore, in this embodiment as well, the same effects as in each of the above embodiments can be obtained.

[Effects of the Invention] As explained above, the vibration isolator according to the present invention is provided with a buoyant body that opens and closes the communication hole of the compartment, and since this buoyant body has a specific gravity equal to or lower than that of the liquid in the compartment, high frequency It is also possible to appropriately attenuate vibrations, and it is possible to obtain a vibration isolating device capable of attenuating vibrations over a wide range.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the first embodiment of the vibration isolator according to the present invention, Fig. 2 is an exploded perspective view of the vibration isolator (22), and Fig. 1fi3 (A) and CB) are the same as those in Fig. 1. 4 is a longitudinal cross-sectional view showing the second embodiment of the present invention, FIG. 5 is a longitudinal cross-sectional view showing the third embodiment of the present invention, and FIG. 6 is a T54 embodiment of the present invention. FIG. 7 is an enlarged view of main parts showing the fifth embodiment of the present invention, FIG. 8 is a perspective view showing a part of FIG. 7,
FIG. 9 is an enlarged sectional view of the main part showing the sixth embodiment of the present invention;
Figure f510 is an enlarged sectional view of the main part showing the seventh example of the present invention. 20--Rubber, 26... φ liquid chamber 28... Vibration absorption unit, 30... Cylindrical body 32, upper disc, 34... Lower disc 36... Holding chamber, 42
... Cylindrical body 44 --- Orifice, 46 # ... Communication hole 48 ... Width communication hole, 54 ... Buoyancy body 56φ ... Buoyancy body, 64 ... Holding chamber 66 ... Buoyancy ball, 68・
... Disk 701 - Communication hole, 72 - Holding chamber 74 - L buoyancy plate, 760 - Orifice 84 - Buoyancy plate. Agent Patent Attorney Atsushi NakajimaFigure 7Figure 8Figure 8

Claims (1)

[Claims] (1) A hollow chamber mainly made of a hollow molded body made of a 9+1 material is used as a liquid chamber, and the liquid chambers are separated from each other through a passage restricting the flow of the liquid confined therein. In a vibration isolating device that uses a strong damping effect on the viscous resistance of liquid flow generated in a restricted passage in combination with a vibration damping function mainly based on internal friction, which is the main vibration absorber, to provide vibration iaI,
A vibration absorbing unit is provided facing at least one of the separated liquid chambers, and this vibration absorbing unit includes a holder having a communication hole with one of the separated liquid chambers, and a holder that is attached to the holder and has a liquid that is approximately equal to or less than the liquid in one of the liquid chambers. Vibration isolator L characterized by comprising: a buoyant body that has a specific gravity and bases a communication hole when the pressure of one liquid chamber rises.