JP2001153173A - Liquid sealed vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid sealed vibration control device generating no abnormal sound. SOLUTION: This liquid sealed vibration control device 2 is provided with a rubber elastic body 8 for mutually connecting a pair of installing members 4, 6; a first diaphragm 12 for forming a liquid chamber 14 between the first diaphragm 12 and the rubber elastic body 8; a first partition member 16 for defining the inside of the liquid chamber 14 into a main liquid chamber 18 and a first sub-liquid chamber 20; a second partition member 32 pressed in the first partition member 16; a second disphragm 48 sandwiched and fixed by the first partition member 16 and the second partition member 32; and a second sub-liquid chamber 46 defined by the second diaphragm 48 and the second partition member 32. The outer peripheral edge 50 of the second diaphragm 48 is compressed by the second partition member 32 and the first partition member 16 to impart deflection to the second diaphragm 48.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filled type vibration damping device.

[0002]

2. Description of the Related Art In an automobile engine, vibrations occur in a wide frequency range. In particular, the engine shakes at about 10 Hz, idles at about 20 to 40 Hz,
It is known that a muffled sound and a vibration at the time of acceleration occur around 200 Hz. Therefore, as a vibration isolator used to support a power unit including an engine, a vibration isolator capable of effectively reducing vibration in a plurality of frequency ranges has been developed (for example, see Japanese Patent Application Laid-Open No. H10-122294). ).

As a vibration isolator of this type, a so-called double orifice type liquid filled type vibration isolator as shown in FIG. 6, for example, is known.

The liquid filled type vibration damping device 56 comprises a liquid chamber 64 defined between a rubber elastic body 60 connecting a pair of mounting members 58a and 58b and a first rubber diaphragm 62.
A first partition member 66 is disposed in the first partition member 6.
6, the liquid chamber 64 becomes the main liquid chamber 6 on the rubber elastic body 60 side.
8 and a first sub-liquid chamber 70 on the first diaphragm 62 side. The second partition member 72 is press-fitted into the first partition member 66, and the first partition member 66 and the second
A second diaphragm 74 made of rubber, which has a substantially disk shape and is formed so that the thickness of the center portion is thicker than the thickness of the peripheral portion, is sandwiched between the partition member 72 and the partition member 72. Then, the second sub liquid chamber 76 located in the first partition member 66 is formed by the second partition member 72 and the second diaphragm 74.
Is defined.

When vibration is input to the liquid-filled type vibration damping device 56 and liquid flows from the main liquid chamber 68 into the second sub liquid chamber 76, the second diaphragm 74 bends and deforms.

A curve e in FIG. 7 shows the reaction force characteristic of the second diaphragm 74 at this time.

The thickness of the second diaphragm 74 at the inner peripheral side of the portion sandwiched between the first partition member 66 and the second partition member 72 is relatively smaller than the thickness of the center portion of the second diaphragm 74. Although the second diaphragm 74 is easily bent and deformed with a small load in the initial stage of deformation, the second diaphragm 74 contacts the regulating projection 78 formed on the inner peripheral side of the first partition member 66. When touching, the second
The bending deformation of the diaphragm 74 is greatly restricted.

That is, the second diaphragm 74 has:
A substantially constant small reaction force is generated until the second diaphragm 74 comes into contact with the regulation protrusion 76, and a large reaction force is generated when the second diaphragm 74 comes into contact with the regulation protrusion 76.

For this reason, the liquid-filled type vibration damping device 56
Can effectively reduce vibrations in different frequency ranges such as engine shake and idle vibration.

[0010]

However, in the above-described structure, when a very large load suddenly acts on the second diaphragm 74 when the engine is started or the vehicle runs on a rough road, the second diaphragm 74 is moved. The first partition member 6
There is a possibility that the undesired noise is generated by colliding with the restriction projection 78 of No. 6.

As a device capable of preventing the generation of such abnormal noise, there is a liquid filled type vibration damping device 80 shown in FIG. The liquid-filled type vibration damping device 80 has substantially the same configuration as the liquid-filled type vibration damping device 56 of FIG. 6 described above.
6, the second diaphragm 74 has a substantially disk-like shape, and is vulcanized and bonded to the inner peripheral surface of the annular metal fitting 82. And
The metal fitting 82 is press-fitted into the inner peripheral side of the first partition member 66. When the metal fitting 82 is press-fitted, the second diaphragm 74 is squeezed and the second diaphragm 74 is bent. It is assembled to the first partition member 66.

That is, in the liquid-filled type vibration damping device 80 shown in FIG. 8, as shown by a curve f in FIG. Can be reduced to a substantially constant small reaction force, and the volume of the second sub liquid chamber 76 increases with the inflow of the liquid from the main liquid chamber 68, and the deflection of the second diaphragm 74 is absorbed. And the second diaphragm 7
4 generates a large reaction force.

Therefore, the liquid filled type vibration damping device 80 shown in FIG. 8 effectively eliminates vibrations in different frequency ranges, such as engine shake and idle vibration, similarly to the liquid filled type vibration damping device 56 shown in FIG. Can be reduced.

Further, the liquid filled type vibration damping device 8 shown in FIG.
No. 0 does not have a configuration corresponding to the regulating projection 78 of the liquid-filled type vibration damping device 56 shown in FIG. 6, so that generation of abnormal noise can be prevented.

However, the liquid filled type vibration damping device 8 shown in FIG.
In the case of 0, there is a problem that the manufacturing cost is increased because the metal fitting 82 is attached to the second diaphragm 74.

[0016]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a rubber elastic member for connecting a power unit-side mounting member, a vehicle body-side mounting member, and a pair of mounting members, which are arranged to face each other. A first diaphragm that is fixed to one of the pair of mounting members and forms a liquid chamber between the rubber elastic body and the first diaphragm, the first diaphragm being disposed in the liquid chamber; A first partition member that is fixed to one of the liquid chambers and defines the liquid chamber as a main liquid chamber on the rubber elastic body side and a first sub liquid chamber on the first diaphragm side, and is press-fitted into the first partition member. A second partition member, a second diaphragm sandwiched and fixed between the first partition member and the second partition member, and the first partition member defined by the second diaphragm and the second partition member. The second located inside the And an outer peripheral edge of the second diaphragm, when the second partition member is press-fitted into the one partition member, when the second partition member is press-fitted into the one partition member. The second diaphragm is compressed by the member and the second diaphragm is flexed. Accordingly, the initial reaction force generated in the second diaphragm becomes a substantially constant small reaction force, and the volume of the second sub liquid chamber increases with the inflow of the liquid from the main liquid chamber. When the deflection of the diaphragm is absorbed, the second
The reaction force generated in the diaphragm is large.

According to a second aspect of the present invention, in the first aspect, the second diaphragm is bonded to the first partition member and the second partition member. Thus, the outer peripheral edge of the second diaphragm sandwiched between the first partition member and the second partition member always maintains the initial compression amount reliably.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

The liquid-sealed type vibration damping device 2 includes a metal mounting member 4 mounted on a power unit side serving as a vibration source.
And a metal attachment member 6 attached to the vehicle body. The attachment members 4 and 6 are connected to each other by a rubber elastic body 8 so as to face each other. The mounting member 6 includes:
A bottom fitting 6a on a bottomed cylinder and a substantially cylindrical upper fitting 6b
By crimping the lower end of the upper fitting 6b, ie, the lower end in FIG. 1, with respect to the upper edge of the bottom fitting 6a, that is, the outer peripheral flange 10 located above in FIG. Are combined. Also,
The inner peripheral surface of the upper fitting 6b is covered with a thin coating 8a extending from the rubber elastic body 8.

Inside the mounting member 6, a first diaphragm 12 made of a rubber material and having a thin and substantially disk shape is mounted.

A liquid chamber 14 in which a liquid is filled is defined between the first diaphragm 12 and the rubber elastic body 8.

The liquid chamber 14 is further defined as a main liquid chamber 18 and a first sub liquid chamber 20 by a first cylindrical metal-made partition member 16 attached to the attachment member 6. ing.

The first partitioning member 16 has a brim-like shape having a diameter larger than the outer diameter of the power unit side end, ie, the upper end in FIG. 1, at the vehicle body end, ie, the lower end in FIG. A flange portion 22 is formed. The outer peripheral edges of the flange portion 22 and the first diaphragm 12 are
Together with the outer peripheral flange 10 of the bottom fitting 6a, it is sandwiched by the lower end of the upper fitting 6b, caulked and fixed. The outer peripheral surface of the first partition member 16 is formed on the inner peripheral surface of the upper metal fitting 6b by the coating portion 8 of the rubber elastic body 8.
It adheres through a.

A groove 24 is formed on the outer peripheral surface of the first partition member 16 in a substantially helical manner. One end of the groove 24 communicates with the main liquid chamber 18 at the end of the first partition member 16 on the power unit side, and the other end has the end of the groove 24 on the vehicle body side of the first partition member 16. It communicates with one sub liquid chamber 20.

That is, the groove 24 allows the first
A first orifice passage 26 is formed between the outer peripheral surface of the partition member 16 and the inner peripheral surface of the upper fitting 6b to communicate the main liquid chamber 18 and the first sub liquid chamber 20.

The inside diameter of the first partitioning member 16 at the end on the vehicle body side is reduced in a substantially stepwise manner over the entire circumference. The reduced diameter portion 28 has an annular groove 3 that opens toward the end of the first partition member 16 on the power unit side.
0 is formed over the entire circumference.

The first partitioning member 16 is press-fitted with a substantially cylindrical bottomed second partitioning member 32. The second partition member 32 has a bottomed end 34 located on the main liquid chamber 18 side,
The opening end 36 is press-fitted so as to be located on the first sub liquid chamber 20 side.

The second partition member 32 includes the bottomed end 3
The outer peripheral surface in the vicinity of 4 is a press-fitting surface 38, and the outer diameter on the side of the opening end 36 is slightly smaller than the outer diameter in the vicinity of the bottomed end 34.

The bottomed end portion 34 is formed with a flange-like flange portion 40 that is in contact with the end surface of the first partition member 16 at the power unit side end over the entire circumference.

On the outer peripheral surface of the second partitioning member 32, a groove 42 having a length substantially making a full circle around the outer peripheral surface is formed. One end of the second orifice passage 44 formed by the groove 42 and the inner peripheral surface of the first partition member 16 communicates with the main liquid chamber 18, and the other end has a second sub liquid chamber described later. It communicates with 46.

The length of the first orifice passage 26 is formed to be longer than the length of the second orifice passage 44. The sectional area of the first orifice passage 26 is set smaller than the sectional area of the second orifice passage 44.

Between the inner peripheral surface of the first partition member 16 at the vehicle body side end and the open end 36 of the second partition member 32, a second rubber diaphragm 48 having a substantially disk shape is provided. It is clamped and fixed.

The second diaphragm 48 and the bottomed end 34 of the second partitioning member 32 have the second
A second sub-liquid chamber 46 adjacent to the first sub-liquid chamber 20 is defined via a diaphragm 48.

The second diaphragm 48 has an outer peripheral edge 50 engaged with the annular groove 30 of the first partition member 16 and the second partition member 32 is connected to the first partition member 1.
6, the outer peripheral edge 50 is compressed.

Since the outer peripheral side of the second diaphragm 48 is in close contact with the inner peripheral surface of the reduced diameter portion 28 of the first partition member 16, this compression causes the second diaphragm 48 to be closed.
Is bent.

Since the second diaphragm 48 of the liquid-filled type vibration damping device 2 is assembled in a bent state, the initial reaction force generated in the second diaphragm 48 is substantially constant as shown in FIG. And the volume of the second sub-liquid chamber 46 increases with the inflow of liquid from the main liquid chamber 18, and when the deflection of the second diaphragm 48 is absorbed, the second A large reaction force is generated in the two diaphragms 48.

Therefore, as shown in FIG. 3, vibrations in a frequency range of about 10 Hz, such as engine shake, are effectively reduced by a large loss factor. The curves a and b in FIG. 3 show the loss factor and the dynamic spring constant of the second diaphragm 48, respectively.

As shown in FIG. 4, vibration in the frequency range of 20 to 30 Hz, such as idle vibration, is effectively reduced with a small dynamic spring constant. Note that a curve c in FIG. 4 indicates a dynamic spring constant of the second diaphragm, and a curve d indicates a conventional dynamic spring constant.

In the liquid-filled type vibration damping device 2 configured as described above, the outer peripheral edge 50 of the second diaphragm 48 is compressed by the first partition member 16 and the second partition member 32, whereby the second diaphragm 48 is compressed. 48 can be flexed, so that vibrations in a plurality of frequency ranges can be reduced without increasing manufacturing costs due to an increase in the number of parts.

Further, even if the second diaphragm 48 is largely bent, there is no interference with the second diaphragm 48, so that generation of abnormal noise can be surely prevented.

As shown in FIG. 5, an adhesive 52 is previously applied to the outer peripheral edge 50 of the second diaphragm 48 sandwiched between the first partition member 16 and the second partition member 32. Thereby, it is possible to reliably prevent the second diaphragm 48 from falling out from between the first partition member 16 and the second partition member 32, and the outer peripheral edge 50 is always in contact with the first partition member 16 and the second partition member 32. The second diaphragm 48 is in close contact with the second diaphragm 48, the initial compression amount is reliably maintained, and the desired amount of flexure can be continuously provided to the second diaphragm 48. Period performance can be reliably obtained.

[0042]

According to the first aspect of the present invention, by press-fitting the second partition member into the first partition member, the outer peripheral edge of the second diaphragm is compressed, and the second diaphragm is bent. Therefore, it is possible to prevent generation of abnormal noise from the liquid-filled type vibration damping device without lowering the performance and increasing the manufacturing cost of the liquid-filled type vibration damping device.

According to the second aspect of the present invention, it is possible to reliably prevent the second diaphragm from falling out from between the first partition member and the second partition member.
Since the outer peripheral edge of the second diaphragm is always maintained at the initial compression amount, the desired performance of the liquid-filled type vibration damping device can be reliably obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a liquid filled type vibration damping device according to the present invention.

FIG. 2 is a reaction force characteristic diagram of a second diaphragm of the liquid filled type vibration damping device according to the present invention.

FIG. 3 is a damping characteristic diagram of the liquid filled type vibration damping device according to the present invention.

FIG. 4 is a dynamic spring characteristic diagram of the liquid filled type vibration damping device according to the present invention.

FIG. 5 is a sectional view of a main part of a liquid-filled type vibration damping device according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional liquid filled type vibration damping device.

FIG. 7 is a reaction force characteristic diagram of a second diaphragm of a conventional liquid filled type vibration damping device.

FIG. 8 is a cross-sectional view of a conventional liquid filled type vibration damping device.

[Explanation of symbols]

 2: Liquid-filled vibration isolator 16: First partition member 20: First sub liquid chamber 28: Reduced diameter part 32: Second partition member 46: Second sub liquid chamber 48: Second diaphragm 50: Outer peripheral edge

Claims (2)

[Claims] 1. A power unit-side mounting member and a vehicle body-side mounting member which are arranged to face each other, a rubber elastic body connecting the pair of mounting members to each other, and fixed to one of the pair of mounting members. A first diaphragm forming a liquid chamber between the rubber elastic body and a first diaphragm disposed in the liquid chamber and fixed to one of the pair of mounting members; A first partition member that defines a main liquid chamber on the body side and a first sub liquid chamber on the first diaphragm side; a second partition member press-fitted into the first partition member; A second diaphragm sandwiched and fixed by the second partition member; and a second sub-liquid chamber defined by the second diaphragm and the second partition member and located inside the first partition member. Smell in liquid filled vibration isolator When the second partition member is pressed into the one partition member,
An outer peripheral edge of the second diaphragm is compressed by the second partition member and the first partition member, and the second diaphragm is flexed. 2. The liquid-filled type vibration damping device according to claim 1, wherein the second diaphragm is bonded to the first partition member and the second partition member.