JP4188751B2 - Liquid-filled vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid-filled vibration isolator used to support a vibrating body such as an automobile engine so that the vibration is not transmitted to a support body such as a vehicle body.
[0002]
[Prior art]
FIG. 5 shows an example of a conventional liquid-filled vibration isolator, and a vibration isolator having a similar structure is disclosed in Japanese Patent Laid-Open No. 2001-50333.
[0003]
In the vibration isolator 100 shown in the figure, a first attachment member 101 attached to the support side and a second attachment member 102 attached to the vibration body side are coupled via a vibration isolation base 103 made of a rubber-like elastic body. In addition, a diaphragm 110 facing the vibration isolating base 103 is provided to form a liquid chamber 104 inside the first mounting member 101, and a partition member 105 is provided to connect the liquid chamber 104 to the upper main liquid chamber 104A and the lower main liquid chamber 104A. The auxiliary liquid chamber 104B is configured to be partitioned.
[0004]
The partition member 105 includes a ring-shaped auxiliary metal fitting 106 and an elastic plate 107 made of a rubber-like elastic body that closes the central opening. The auxiliary metal fitting 106 is provided with a vertical wall portion 106 </ b> A that extends downward in the axial direction from the inner peripheral edge thereof, and the vertical wall portion 106 </ b> A is embedded in the peripheral edge portion of the elastic plate 107, thereby A rigid wall 108 protruding in the direction is provided. Then, by pressing the rigid wall 108 against the peripheral edge of the diaphragm 110, an orifice channel 109 that connects the main liquid chamber 104A and the sub liquid chamber 104B is formed on the outer periphery of the rigid wall 108.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-50333
[Problems to be solved by the invention]
In the vibration isolator 100 having the above structure, abnormal noise may occur when the first mounting member 101 and the second mounting member 102 are relatively displaced in the axial direction, and the generation of such abnormal noise is prevented. It is requested to do.
[0007]
An object of the present invention is to prevent the generation of abnormal noise during a large displacement as described above in a liquid-filled vibration isolator.
[0008]
[Means for Solving the Problems]
As the inventor scrutinizes the cause of the abnormal noise, the abnormal noise is in a direction in which the vibration-proof base is compressed (a direction in which the first mounting member and the second mounting member approach in the axial direction). It has been found that this occurs not in the case of a large displacement in the case of large displacement in the tension direction of the vibration-proof base (the direction in which the first mounting member and the second mounting member are separated in the axial direction). Then, in view of the nature of the sound, etc., I thought that abnormal noise might occur due to cavitation. That is, when the liquid chamber suddenly becomes negative pressure due to the large displacement of the vibration isolating substrate in the pulling direction, the liquid flow from the sub liquid chamber to the main liquid chamber is caused to flow through the orifice channel in the conventional vibration isolator. It was thought that it was difficult to alleviate the pressure change because it was a completely passing flow, so that bubbles were generated by cavitation, leading to abnormal noise. Then, on the wall that forms the orifice channel on the outer periphery and divides it from the inner sub-liquid chamber, the liquid that short-circuits a part of the orifice channel at the time of large displacement in the tensile direction as described above. It has been found that by providing a structure for generating a flow, cavitation can be reduced and generation of abnormal noise can be prevented, and the present invention has been completed.
[0009]
A liquid-filled vibration isolator according to the present invention is interposed between a first mounting member having a cylindrical portion, a second mounting member disposed on the axial center of the cylindrical portion, and the mounting members. And a diaphragm for forming a liquid chamber between the anti-vibration base and the anti-vibration base disposed between the anti-vibration base and the anti-vibration base. And a partition member that divides the liquid chamber into a main liquid chamber in which a part of the chamber wall is formed by the vibration isolating base and a sub liquid chamber in which a part of the chamber wall is formed by the diaphragm. In the liquid-filled vibration isolator, an elastic wall that protrudes in the axial direction and extends in the circumferential direction is provided on the peripheral edge of one of the partition member and the diaphragm, and the main liquid chamber and the sub liquid chamber are connected to the outer periphery thereof. Forming an orifice flow path, and in front of the other peripheral portion of the partition member and the diaphragm. The regulating portion for regulating a deformation in the radially inward elastic wall provided, wherein the regulating portion, a restricting wall extending in circumferential direction provided on the periphery of the other, higher rigidity than the elastic wall The elastic wall is set and abutted on the inner peripheral surface of the elastic wall to restrict the deformation of the elastic wall inward in the radial direction .
[0010]
In this liquid-filled vibration isolator, when a predetermined displacement or more is applied in the tension direction of the vibration isolator base, the elastic wall is bent outwardly in the radial direction to form a gap, and the liquid in the sub liquid chamber is Leakage into the orifice channel from this gap. That is, the liquid in the sub liquid chamber flows into the orifice flow channel not only from the normal communication port on the sub liquid chamber side in the orifice flow channel but also from the midway of the orifice flow channel due to the bending deformation of the elastic wall. Therefore, it is possible to reduce cavitation and prevent the generation of abnormal noise. On the other hand, when a predetermined displacement or more is applied in the compression direction of the vibration isolating base, the inward deformation of the elastic wall can be restricted by the restricting portion.
[0011]
The restricting portion is a restricting wall provided in the other peripheral portion and extending in the circumferential direction. The restricting portion is set to be higher in rigidity than the elastic wall and is disposed in contact with the inner peripheral surface of the elastic wall. The elastic wall is provided to restrict deformation inward in the radial direction .
[0012]
In this case, the restricting wall only needs to have higher rigidity than the elastic wall against bending deformation in the radial direction, that is, in the direction perpendicular to the axis of the vibration isolator. The wall need not be rigid enough not to deform. More specifically, the restriction wall has a rigidity that can restrict the inward deformation of the elastic wall when the displacement in the compression direction is large, and the gap for the leak is large when the displacement in the tension direction is large. It is preferable to have rigidity that is integral with the elastic wall so as not to bend outward and be deformed. As long as the regulating wall has such rigidity, it can be composed only of a rubber-like elastic body, or may be a rubber-like elastic body reinforced by embedding a rigid body such as metal, Furthermore, it can also be comprised only with rigid bodies, such as a metal.
[0013]
In the liquid filled type vibration damping device of the present invention, the elastic wall is provided at a peripheral portion of the diaphragm, the restriction wall is provided at a peripheral portion of the partition member, and the partition member includes at least the restriction wall. It is preferable that the inner part is composed only of a rubber-like elastic body. In this case, the pressure fluctuation in the liquid chamber can be reduced by bending and deforming the central portion of the partition member when the vibration isolating base body is largely displaced. In addition, when the displacement of the vibration isolating base is large in the pulling direction, the central portion of the partition member is bent and deformed toward the main liquid chamber, and accordingly, the restriction wall tends to bend and deform radially inward. It is easy to secure a larger gap for the leak between the elastic wall and the elastic wall that is bent outward in the radial direction. Further, at the time of large displacement in the compression direction of the vibration-proof substrate, the central portion of the partition member is bent and deformed toward the sub liquid chamber side, and accordingly, the restriction wall is bent and deformed radially outward. The closeness with the outer peripheral elastic wall can be increased.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a liquid-filled vibration isolator 10 according to an embodiment of the present invention will be described with reference to the drawings.
[0015]
The vibration isolator 10 is an engine mount that supports an automobile engine with respect to a vehicle body, and includes a lower metal first attachment member 12 that has a cylindrical portion 11 and is fixedly attached to a bracket 1 on the vehicle body side. The upper metal second mounting member 14 which is disposed on the shaft center with an interval therebetween and fixed to the engine-side bracket 2 is coupled via a vibration-isolating base 16 made of a rubber-like elastic body. Thus, vibration is applied in the vertical direction, that is, in the axial direction of the first mounting member 12.
[0016]
The anti-vibration base 16 has a substantially frustoconical outer shape, and the lower portion of the second mounting member 14 is embedded on the upper axis thereof by vulcanization molding means. 1 Attached to the upper inner peripheral surface of the mounting member 12 by vulcanization molding means.
[0017]
A diaphragm 18 is mounted on the lower side of the first mounting member 12 so as to face the vibration isolation base 16. The diaphragm 18 includes a thin rubber film 20 as a flexible film and a cylindrical auxiliary metal fitting 22 vulcanized and bonded to the outer periphery thereof, and the upper outer periphery of the auxiliary metal fitting 22 is the lower end of the first mounting member 12. It is fixed by caulking with 12A.
[0018]
A liquid chamber 24 sealed between the diaphragm 18 and the vibration isolation base 16 is formed inside the first mounting member 12, and the liquid is sealed in the liquid chamber 24. In the liquid chamber 24, a disk-shaped partition member 28 that forms an orifice channel 26 is provided on the outer periphery, and the liquid chamber 24 is partitioned vertically by the partition member 28. That is, between the vibration isolating substrate 16 and the diaphragm 18 inside the first mounting member 12, a main liquid chamber 24A in which a part of the chamber wall is formed by the vibration isolating substrate 16, and an orifice in the main liquid chamber 24A. A sub-liquid chamber 24 </ b> B that is connected via the flow path 26 and in which a part of the chamber wall is formed by the diaphragm 18 is provided adjacent to each other via the partition member 28.
[0019]
The partition member 28 includes a disk-shaped elastic plate portion 32 made of a rubber-like elastic body and a ring-shaped auxiliary metal fitting 30 integrally vulcanized and bonded to the peripheral portion thereof, and the orifice channel 26 is closed. When vibration in such a high frequency range is applied, the elastic plate portion 32 is configured to exhibit vibration proof performance. The outer peripheral edge of the auxiliary metal fitting 30 is caulked and fixed together with the auxiliary metal fitting 22 of the diaphragm 18 by the lower end 12 </ b> A of the first mounting member 12, whereby the partition member 28 is fixed in the liquid chamber 24.
[0020]
The auxiliary metal fitting 22 of the diaphragm 18 has a tapered cylindrical shape whose diameter is reduced toward the lower side in the axial direction, and the orifice channel 26 is formed inside thereof. In addition, an elastic wall 34 that protrudes toward the main liquid chamber 24 </ b> A on the upper side in the axial direction and extends in the circumferential direction is formed of a rubber-like elastic body integrated with the thin rubber film 20 at the peripheral edge of the diaphragm 18. Then, by bringing the elastic wall 34 into contact with the peripheral edge of the partition member 28, an orifice channel 26 is formed between the outer periphery of the elastic wall 34 and the auxiliary metal fitting 22. A partition 34 is formed on the outer periphery of the auxiliary liquid chamber 24B. The elastic wall 34 is formed of only an elastic material such as rubber or a thermoplastic elastomer so that it can bend and deform radially outward when a certain negative pressure or more is generated in the orifice channel 26.
[0021]
On the other hand, on the peripheral edge of the partition member 28, a regulating wall 36 that protrudes in the axially lower sub liquid chamber 24 </ b> B side and extends in the circumferential direction is formed of a rubber-like elastic body that is integral with the elastic plate portion 32. The restricting wall 36 is fitted inside the elastic wall 34, whereby the elastic wall 34 can be bent and deformed radially outward, but is deformed and deformed by the restricting wall 36 radially inward. Regulated and blocked.
[0022]
Specifically, the regulation wall 36 is formed thick so that the rigidity is higher than that of the elastic wall 34. In addition, a horizontal stepped portion 38 is provided on the outer peripheral side of the regulating wall 36 at the peripheral portion of the partition member 28, and the tip end surface of the elastic wall 34 is brought into contact with the stepped portion 38. By doing so, the wall portion on the inner peripheral side of the orifice channel 26 is formed in an inner-outer double by the regulating wall 36 and the elastic wall 34.
[0023]
The elastic wall 34 is provided with a ridge 40 extending in the circumferential direction on the inner peripheral surface thereof, and a concave groove 42 extending in the circumferential direction is provided on the outer peripheral surface of the regulating wall 36 opposed thereto. It is assembled to match. Instead of this, the elastic wall 34 may be provided with a concave groove, and the regulating wall 36 may be provided with a ridge.
[0024]
As shown in FIGS. 1 and 4C, the partition member 28 is provided with a blocking portion 44 that protrudes radially outward at one location on the circumference and blocks the orifice channel 26. A first communication port 46 that communicates the orifice channel 26 to the main liquid chamber 24A side and a second communication port 48 that communicates the orifice channel 26 to the sub-liquid chamber 24B side are formed on both sides in the circumferential direction across the gap. Has been. As a result, the orifice passage 26 communicates the main liquid chamber 24A and the sub liquid chamber 24B with each other with a length of substantially one round in the circumferential direction.
[0025]
The first communication port 46 is formed by providing an opening extending vertically through the auxiliary metal fitting 30, and the second communication port 48 is formed by cutting out the restriction wall 36 at a part in the circumferential direction. ing. A reinforcing wall portion 50 is provided on the inner peripheral edge of the auxiliary metal fitting 30 so as to protrude downward in the axial direction from the blocking portion 44 to the position where the first communication port 46 is disposed. Reinforcing prevents undesired short circuit with the auxiliary liquid chamber 24B.
[0026]
In the liquid filled type vibration damping device 10 of the present embodiment configured as described above, as shown in FIG. 2, at the time of small displacement (that is, when axial vibration with a predetermined amplitude or less is input, for example, ± 0.5 mm). The liquid flow occurs through the orifice channel 26 between the main liquid chamber 24A and the sub liquid chamber 24B, and the vibration damping function can be exhibited by the flow effect. Note that the elastic modulus of the elastic wall 34, the degree of fitting with the regulating wall 36, and the like are set so that the elastic wall 34 does not bend and deform during such a small displacement.
[0027]
On the other hand, when a large displacement, for example, ± 6.0 mm of axial vibration is input, the following occurs. First, when the vibration isolator base 16 is largely displaced in the compression direction (that is, when a displacement of a predetermined amount or more is applied in the direction in which the first mounting member 12 and the second mounting member 14 approach each other), the regulation wall 36 is elastic. Since the bending deformation to the inside of the wall 34 is prevented, the liquid can flow from the main liquid chamber 24A to the sub liquid chamber 24B only through the orifice channel 26 as shown in FIG. The liquid flow effect of the orifice channel 26 can be exhibited. It should be noted that the restriction wall 36 does not necessarily need to completely prevent the inward deformation of the elastic wall 34 until such a large displacement. This is because the orifice channel 26 is originally intended for vibration damping at the time of a small displacement as described above, and a sufficient liquid flow effect cannot always be obtained at the time of a large displacement.
[0028]
Then, when the vibration isolating base 16 is displaced greatly in the pulling direction (that is, when a predetermined displacement or more is applied in the direction in which the first mounting member 12 and the second mounting member 14 are separated), as shown in FIG. In addition, since the elastic wall 34 has no restriction wall on the outer periphery thereof, the inside of the orifice channel 26 becomes a negative pressure, and is bent and deformed outward in the radial direction by its own elasticity. As a result, the liquid in the auxiliary liquid chamber 24B leaks not only from the communication port 48 but also from the position where it is bent and deformed as indicated by the arrow X, and flows into the orifice channel 26. Therefore, the pressure change in the liquid chamber 24 can be relieved and cavitation can be reduced, thereby preventing the generation of abnormal noise. The bending deformation of the elastic wall 34 is temporary accompanying the change in hydraulic pressure, and when the negative pressure is eliminated, the original state shown in FIG. 1 is restored.
[0029]
In the present embodiment, in particular, the partition member 28 is constituted by a ring-shaped auxiliary metal fitting 30 at the peripheral edge and a disk-shaped elastic plate portion 32 that closes the opening, and includes a regulating wall 36 and the inside thereof. Since the portion is composed only of the rubber-like elastic body, the elastic plate portion 32 bends and deforms at the time of large displacement, so that the pressure fluctuation in the liquid chamber 24 can be reduced and the following effects can be obtained.
[0030]
That is, when the vibration isolator base 16 is displaced greatly in the pulling direction, the inside of the main liquid chamber 24A becomes negative pressure, so that the elastic plate 32 at the center of the partition member 28 is pulled upward, that is, toward the main liquid chamber 24A. Accordingly, the restriction wall 36 tends to bend and deform radially inward (in the direction indicated by the arrow Y in FIG. 3). Therefore, it becomes easier to secure a larger gap for the leak between the elastic wall 34 that is bent outward in the radial direction. Further, when the vibration isolator base 16 is displaced in the compression direction, the inside of the main liquid chamber 24A is pressurized, so that the elastic plate portion 32 is pushed to the sub liquid chamber 24B side. It is likely to bend and deform radially outward (in the direction indicated by arrow Z in FIG. 2), thereby increasing the closeness with the outer peripheral elastic wall 34.
[0031]
In the above embodiment, the diaphragm 18 is provided with the elastic wall 34, and the partition member 28 is provided with the restriction wall 36 that restricts the inward deformation thereof. An elastic wall may be provided at the peripheral edge, and a restriction wall for restricting the inward deformation of the elastic wall may be provided at the peripheral edge of the diaphragm. In that case, the elastic wall of the partition member may be brought into contact with the peripheral edge of the diaphragm and the orifice channel may be formed on the outer periphery thereof.
[0032]
【The invention's effect】
According to the present invention, the flow of the normal orifice channel is ensured when the vibration-proof base is small or large in the compression direction, and the liquid in the sub liquid chamber is discharged when large in the tensile direction in which abnormal noise is generated. It is possible to leak into the orifice flow path so as to short-circuit a part of the orifice flow path, thereby reducing cavitation and preventing abnormal noise.
[Brief description of the drawings]
FIG. 1 is a vertical cross-sectional view (cross-sectional view taken along the line II in FIG. 4C) of a liquid-filled vibration isolator according to one embodiment of the present invention.
FIG. 2 is a cross-sectional view of the vibration isolator when the vibration isolator base body is small displaced and a large displacement in the compression direction (a diagram corresponding to a cross section taken along line II-II in FIG. 4C).
FIG. 3 is a cross-sectional view of the vibration isolator when the vibration isolator base is largely displaced in the tensile direction.
4A is a top view of a partition member, FIG. 4B is a cross-sectional view of the partition member, and FIG. 4C is a bottom view of the partition member.
FIG. 5 is a longitudinal sectional view of a conventional liquid-filled vibration isolator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Cylindrical part 12 ... 1st attachment member 14 ... 2nd attachment member 16 ... Vibration-proof base 18 ... Diaphragm 24 ... Liquid chamber 24A ... Main liquid chamber 24B ... Sub-liquid chamber 26 ... Orifice channel 28 ... partition member 34 ... elastic wall 36 ... regulating wall

Claims (2)

A first mounting member having a cylindrical portion, a second mounting member disposed on the axial center of the cylindrical portion, and a rubber-like elastic body interposed between the mounting members and connecting the two mounting members. An anti-vibration base, a diaphragm which is disposed opposite to the anti-vibration base and forms a liquid chamber between the anti-vibration base and the anti-vibration base inside the first mounting member, and the liquid chamber is attached to the anti-vibration base. In a liquid-filled vibration isolator comprising: a main liquid chamber in which a part of the chamber wall is formed; and a partition member that partitions the sub-liquid chamber in which a part of the chamber wall is formed by the diaphragm;
An elastic wall that protrudes in the axial direction and extends in the circumferential direction is provided on the peripheral edge of one of the partition member and the diaphragm, and an orifice channel that connects the main liquid chamber and the sub liquid chamber is formed on the outer periphery thereof. A restricting portion for restricting deformation of the elastic wall inward in the radial direction is provided on the other peripheral portion of the partition member and the diaphragm ,
The restricting portion is a restricting wall provided in the other peripheral portion and extending in the circumferential direction. The restricting portion is set to be higher in rigidity than the elastic wall and is disposed in contact with the inner peripheral surface of the elastic wall. , hydraulic antivibration apparatus characterized by regulating the deformation of the radially inwardly of the elastic wall. The elastic wall is provided at a peripheral edge of the diaphragm, the restriction wall is provided at a peripheral edge of the partition member, and the partition member includes at least the restriction wall and a portion inside the rubber member is only a rubber-like elastic body. in fact it constructed hydraulic antivibration device according to claim 1, wherein.

Images