JP2006177526A - Fluid-sealed vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid-sealed vibration isolator comprising a hydraulic absorbing structure of a new structure inhibiting the generation of noise or the like by reducing impact caused by repeated contact to/separation from a contact portion of a movable plate constituting the hydraulic absorbing mechanism. <P>SOLUTION: In this fluid sealed vibration isolator 10 wherein contact portions 56, 58 opposite to each other at an interval are mounted on a partitioning member 32 at least at one side of the movable plate 66, and displacement quantity of the movable plate 66 is limited by the contact with the contact portions 56, 58, the movable plate 66 is composed of a rubber elastic plate, and at least one of contact faces of the movable plate 66 and the partitioning member 32 is a low-frictional face on which friction reducing treatment is performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anti-vibration device used as, for example, an automobile engine mount and the like, and more particularly, a fluid-filled anti-vibration device that obtains an anti-vibration effect by utilizing the flow action of an incompressible fluid enclosed therein. It is about.

  Conventionally, as a kind of anti-vibration coupling body or anti-vibration support body mounted between members constituting the vibration transmission system, for example, a fluid as described in Japanese Utility Model Publication No. 4-33478 (Patent Document 1) Enclosed vibration isolation devices are known. Such a vibration isolator is generally a vibration isolator in which a first mounting member and a second mounting member are connected by a main rubber elastic body, and a pressure receiving portion in which a part of a wall portion is configured by the main rubber elastic body. A chamber and an equilibrium chamber in which a part of the wall portion is formed of an easily deformable flexible film are provided, and an incompressible fluid is enclosed in the pressure receiving chamber and the equilibrium chamber. The pressure receiving chamber and the equilibrium chamber are communicated with each other based on a relative pressure fluctuation caused between the pressure receiving chamber and the equilibrium chamber when vibration is input between the first mounting member and the second mounting member. The vibration isolating effect can be exhibited based on the resonance action of the fluid that can flow through the orifice passage formed as described above.

  Further, the vibration isolation effect based on the resonance action of the incompressible fluid that is caused to flow through the orifice passage can only be effectively exhibited in a specific frequency range that has been tuned in advance. Therefore, a hydraulic pressure absorbing mechanism using a movable plate has been proposed in order to improve the anti-vibration performance by avoiding a markedly high dynamic spring at the time of vibration input in a frequency range higher than the tuning frequency range of the orifice passage. This hydraulic pressure absorbing mechanism generally has a structure in which an accommodation space is formed in a partition member that partitions the pressure receiving chamber and the equilibrium chamber, and a movable plate is accommodated and arranged so as to be minutely displaceable with respect to this accommodation space. The storage space is connected to the pressure receiving chamber and the equilibrium chamber through the through holes, respectively, through which the pressure of the pressure receiving chamber is exerted on one surface of the movable plate and the pressure of the equilibrium chamber is exerted on the other surface. It is supposed to be.

  And by the displacement of the movable plate based on the pressure difference between the pressure receiving chamber and the equilibrium chamber, minute pressure fluctuations in the pressure receiving chamber at the time of vibration input in the high frequency range are released to the equilibrium chamber and absorbed. On the other hand, at the time of vibration input in the low frequency range where the orifice passage is tuned, the amplitude of the vibration is large, so that the movable plate comes into contact with the inner surface of the accommodation space and is substantially closed, and the through hole is substantially blocked. Will end up. Therefore, the pressure absorption of the pressure receiving chamber by the hydraulic pressure absorption mechanism is avoided, and the relative pressure fluctuation between the pressure receiving chamber and the equilibrium chamber is effectively generated, and the fluid flow through the orifice passage between these two chambers A sufficient amount is ensured so that the vibration isolation effect by the orifice passage is exhibited.

  However, in such a hydraulic pressure absorption mechanism, when a large amplitude vibration is input and a sudden pressure fluctuation is generated in the pressure receiving chamber, the movable plate repeatedly strikes and separates from the inner surface of the accommodation space. Become. It has been pointed out that the shock at that time is transmitted as vibration to the vehicle body and the like, and the problem of noise in the vehicle interior occurs due to the resonance phenomenon of each member. Specifically, for example, when such an anti-vibration device is adopted as an engine mount for an automobile, there is a possibility that an abnormal noise or the like that can be heard by the driver may occur when the engine is cranked or over a step. is there.

  In order to cope with such a problem, for example, in Japanese Utility Model Publication No. 4-33478 (Patent Document 1), the movable plate is formed of a rubber elastic plate, and a lip-shaped small protrusion is integrally formed on the surface thereof. However, it has also been proposed to absorb the impact at the time of hitting with these small protrusions. However, although such a small protrusion has a certain effect, it is still difficult to exert a sufficient effect, and further measures have been desired.

Japanese Utility Model Publication No. 4-33478

  Here, the present invention has been made in the background as described above, and the problem to be solved is to repeatedly contact / separate the contact portion of the movable plate constituting the hydraulic pressure absorbing mechanism. It is an object of the present invention to provide a fluid-filled vibration isolator equipped with a novel structure of a hydraulic pressure absorbing mechanism that can reduce the occurrence of an impact caused by the noise and suppress the occurrence of abnormal noise and the like.

[New knowledge forming the basis of the present invention]
In order to solve the above-mentioned problems, the present inventor conducted a number of experiments and studies on a conventional fluid-filled vibration isolator, and as a result, found a very interesting fact. As a result of analyzing the relationship between the contact / separation with the partition member accompanying the displacement of the movable plate and the vibration generated along with it with high accuracy, the impact generated by striking the movable plate against the partition member is exclusively. This is because the conventional common sense, which was thought to cause abnormal noise as described above, was actually wrong.

  Specifically, a fluid-filled vibration isolator having the same basic structure as the embodiment of the present invention to be described later, which does not have the present invention applied to its movable plate or partition member, has a large amplitude (± The pressure change in the pressure receiving chamber at the time of vibration input of 2 mm) and the detected value of the vibration level generated in the partition member are measured, and such measurement results are shown on the time axis schematically in FIG. In addition, about the structure of this vibration isolator, description is abbreviate | omitted considering the column of below-mentioned embodiment. Further, in FIG. 18, the dynamic load, which is the detected value of the vibration level, is a signal obtained by passing the detected value of the vibration level in the partition member through a high-pass filter of 100 Hz. As shown in this graph, a small increase / decrease step portion: a appears on the intermediate level of the pressure fluctuation in the pressure receiving chamber when the vibration is input with such a large amplitude that the movable plate hits the contact portions on both sides. . This increase / decrease step part a is considered to be caused by the movable plate being separated from one abutting part and abutting on the other abutting part. This can be confirmed from the fact that the vibration level in the partition member is observed on the time axis corresponding to the increase / decrease step portion a.

  However, when the detected value of the vibration level was observed in contrast to the pressure fluctuation in the pressure receiving chamber, it was found that the vibration level was detected in both the first half and the second half of the increase / decrease step part a. Moreover, it was confirmed that the vibration level detected at the first half part: a-1 and the vibration level detected at the second half part: a-2 are characteristically different.

  This is because the abnormal noise generated when the large amplitude vibration is input to the vibration isolator as described above is mainly due to the impact generated when the movable plate hits the abutting portion with displacement. This is a phenomenon that cannot be understood by conventional recognition. That is, the vibration is generated before the movable plate hits the contact portion, and the vibration generated when the movable plate is displaced includes a material different from the vibration when the movable plate hits the contact portion. That was observed.

  Therefore, as a result of further research based on the fact newly acquired in this way, the present inventor found that the vibration level observed in the first half of the pressure-receiving chamber pressure increase / decrease step part: a-1 is It has been recognized that the vibration is generated when the movable plate is released from the contact state with the contact portion. The cause of this vibration is that the movable plate pressed against the abutting portion is caused to slide and displace on the abutting surface due to its own elastic recovery, fluid pressure, etc. The stick-slip phenomenon occurs when the elastic deformation part of the movable plate that has entered the provided through-hole is displaced so as to rub the opening edge of the through-hole when it is restored and deformed so as to come out of the through-hole. I have come to the presumptive view that this is probably the case.

  Further, in the experimental data shown in the graph of FIG. 18, the latter half part: a-2 shows a larger value than the first half part: a-1 of the detected vibration level. It was also confirmed that the relative value changed according to the magnitude of the input vibration. Particularly, the detected vibration level of the first half part: a-1 is substantially constant regardless of the magnitude of the input amplitude, but the detected vibration level of the second half part: a-2 is accompanied by the magnitude of the input amplitude. It has also been confirmed by a separate experiment result. Specifically, when the amplitude of the input vibration is large, the detected vibration level is increased in the second half part: a-2, and the generated vibration in the second half part: a-2 becomes dominant with respect to problems such as noise generated. On the other hand, when the amplitude of the input vibration is reduced, the detected vibration level becomes relatively high with respect to the first half part: a-1 with respect to the second half part: a-2. The vibration generated by a-1 has a great influence.

  This phenomenon can be achieved by, for example, forming a shock-absorbing projection on the surface of the movable plate to suppress the impact at the time of contact with the contact portion of the movable plate. About the fact that there is a limit to the extent, and the fact that when the amplitude of the input vibration is small, the impact mitigation at the time of contact with the contact part of the movable plate cannot be so effective for noise reduction, An accurate answer can be given. That is, the impact when the movable plate hits the contact portion varies depending on the amplitude of the input vibration, but if there is an impact when the movable plate moves away from the contact portion, it is considered that it does not vary greatly depending on the amplitude. . Therefore, no matter how much the impact on the contact portion of the movable plate can be reduced, noise due to the impact when the movable plate leaves the contact portion remains. Also, if the input vibration amplitude becomes smaller, the impact when the movable plate moves away from the contact portion becomes dominant, so no matter how many configurations are used to mitigate the impact when the movable plate strikes, the movable plate can move. It is considered that an effective reduction effect cannot be exhibited for noise caused by an impact when the plate is separated from the contact portion.

[Solution]
The features of the present invention made to solve the above-described problems based on the newly obtained knowledge as described above are as follows. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

(Aspect 1 of the present invention)
A feature of the first aspect of the present invention is that the first mounting member and the second mounting member are connected by a main rubber elastic body, and a part of the wall portion is configured by the main rubber elastic body so that a vibration is input. Both sides sandwiching a partition member supported by the second mounting member, a pressure receiving chamber in which pressure fluctuation is generated, and an equilibrium chamber in which a part of the wall portion is made of a flexible film and volume change is allowed Each of which is filled with an incompressible fluid, the pressure receiving chamber and the equilibrium chamber are filled with the incompressible fluid, and an orifice passage is provided to communicate the pressure receiving chamber and the equilibrium chamber with each other. The pressure receiving chamber at the time of vibration input so that the pressure of the pressure receiving chamber is exerted on one surface of the movable plate and the pressure of the equilibrium chamber is exerted on the other surface. A small pressure fluctuation in the chamber is released to the equilibrium chamber through the movable plate and absorbed. In addition, a fluid which is provided with a contact portion facing the at least one side of the movable plate on the partition member so that the displacement amount of the movable plate is limited by the contact with the corresponding contact portion. In the enclosed vibration isolator, the movable plate is made of a rubber elastic plate, and at least one contact surface of the movable plate and the partition member is a low-friction surface subjected to low friction treatment. In the shaker.

  In the fluid-filled vibration isolator having the structure according to this aspect, the low dynamic spring effect is exhibited based on the pressure fluctuation absorbing action of the pressure receiving chamber accompanying the displacement of the movable plate with respect to the input vibration of high frequency and small amplitude. As a result, good vibration isolation performance is realized. In this case, the movable plate hardly comes into contact with the contact portion. On the other hand, for the input vibration of low frequency and large amplitude, the movable plate is brought into contact with the abutting portion and is restrained from displacement, so that it is based on the relative pressure fluctuation caused between the pressure receiving chamber and the equilibrium chamber. The fluid flow through the orifice passage is generated, and the vibration isolation effect is exhibited based on the resonance action of the fluid.

  Therefore, there is a concern about the occurrence of an impact when the movable plate repeats contact and separation with respect to the contact portion at the time of inputting the low frequency large amplitude vibration, but in this aspect, at least the movable plate and the partition member Based on the fact that one abutment surface is a low friction surface and the friction coefficient of the abutment portion between the movable plate and the partition member is reduced, especially when the movable plate moves away from the partition member, stick slip Occurrence of abnormal noise due to a phenomenon or the like is effectively suppressed. In addition, it can be expected that the impact when the movable plate comes into contact with the contact portion is alleviated by the low friction surface.

  Therefore, in the fluid-filled vibration isolator according to this aspect, the occurrence of impacts due to repeated contact and separation with respect to the contact portion of the movable plate, and hence the generation of abnormal noise or the like, can be effectively suppressed. Thus, the vibration proof performance can be improved.

(Aspect 2 of the present invention)
A feature of aspect 2 of the present invention is that in the fluid filled type vibration damping device according to aspect 1 of the present invention, the low friction surface is a friction coefficient at the contact surface between the movable plate and the partition member: μ Is in the incompressible fluid such that μ ≦ 1.

  In this aspect, the low friction performance on the contact surface between the movable plate and the partition member is more advantageously exhibited, and the target noise reduction effect can be obtained more stably.

(Aspect 3 of the present invention)
A feature of aspect 3 of the present invention is that, in the fluid filled type vibration damping device according to aspect 1 or 2 of the present invention, the movable plate is formed of self-lubricating rubber so that the contact surface of the movable plate Is the low friction surface.

  In this aspect, low-friction processing on the contact surface is simplified, and noise is suppressed while advantageously improving manufacturing efficiency and reducing costs.

  The self-lubricating rubber of this embodiment is not particularly limited, and conventionally known rubbers can be used. For example, JP-A-8-270728, JP-A-10-89393, and JP-A-2003-65387 can be used. As shown in the Gazettes, etc., rubber elastomers containing various natural rubbers and synthetic rubbers, which are blended with various lubricants such as unsaturated fatty acid amides and silicone oils, are suitably used. Is done.

(Aspect 4 of the present invention)
A feature of aspect 4 of the present invention is that, in the fluid filled type vibration damping device according to any one of aspects 1 to 3 of the present invention, the contact surface of the partition member has a surface roughness Ra ≦ 1. By making a smooth surface of 6 μm, the contact surface of the partition member is the low friction surface.

  In this embodiment, the low friction treatment is effectively performed, and abnormal noise is more advantageously suppressed, and a large degree of freedom in design of the movable plate and the like is ensured, and the desired vibration-proofing effect. Can be obtained stably. In addition, the surface roughness which concerns on this aspect says arithmetic mean roughness (Ra) which is one of the display methods prescribed | regulated by the definition and display of the surface roughness of JIS B0601-1994.

(Aspect 5 of the present invention)
A feature of the fifth aspect of the present invention is that, in the fluid filled type vibration damping device according to any one of the first to fourth aspects of the present invention, the contact surface of the partition member is formed with a coating layer made of a low friction resin. Thus, the contact surface of the partition member is the low friction surface.

  In this embodiment, the low friction treatment is effectively performed, and abnormal noise is more advantageously suppressed. The coating layer made of a low friction resin is not particularly limited, and in consideration of the required low friction performance, durability, cost, etc., for example, fluorine, silicone, polytetrafluoroethylene, polyethylene, etc. Is preferably employed. That is, the above-described aspect 1 and the like in the present invention includes the entire partition member made of such a low-friction resin material. In this aspect, in particular, the partition member is formed of a metal material, for example. Since only the surface of the contact portion can be coated with a low friction resin, for example, it is possible to reduce the friction of the contact surface while maintaining the rigidity of the partition member at a high level. .

(Aspect 6 of the present invention)
A feature of aspect 6 of the present invention is that, in the fluid-filled vibration isolator according to any one of aspects 1 to 5 of the present invention, the movable plate is displaceable separately from the partition member. The movable plate is accommodated in the accommodating space formed in the partition member, and both sides of the movable plate in the displacement direction are respectively configured to the abutting portions formed by the walls of the accommodating space of the partition member. The amount of displacement to both sides of the movable plate is limited by the contact.

  In this embodiment, since the initial displacement of the movable plate is easily allowed, the low dynamic spring effect based on the pressure absorbing action of the pressure receiving chamber at the time of inputting high frequency small amplitude vibration is more effectively exhibited. . In addition, since the displacement of the movable plate is reliably limited by contact with the contact portion on both sides in the displacement direction, pressure fluctuations in the pressure receiving chamber are efficiently generated when low frequency large amplitude vibration is input. Accordingly, the vibration isolation effect by the orifice passage can be effectively exhibited. Preferably, in the present embodiment, low friction surfaces are formed on the contact surfaces with respect to the contact portions on both sides in the displacement direction of the movable plate.

(Aspect 7 of the present invention)
A feature of aspect 7 of the present invention is that, in the fluid filled type vibration damping device according to any one of aspects 1 to 5 of the present invention, the movable plate is fixedly fixed at its outer peripheral edge by the partition member. In other words, the displacement is allowed based on the elastic deformation of the movable plate.

  In this embodiment, pressure leakage through the outer peripheral edge of the movable plate in the pressure receiving chamber is more reliably suppressed, and fluid tightness between the pressure receiving chamber and the equilibrium chamber is advantageously exhibited. Therefore, the vibration isolation effect based on the resonance action of the fluid flowing through the orifice passage is more stably exhibited.

(Aspect 8 of the present invention)
A feature of Aspect 8 of the present invention is that in the fluid filled type vibration damping device according to any one of Aspects 1 to 7 of the present invention, at least a part of a contact surface of the movable plate to the contact portion. Is a corrugated uneven surface spreading in a substantially wave shape with continuous unevenness.

  In this embodiment, when the movable plate and the partition member are brought into contact with each other, the impact is reduced when hitting using the corrugated surface of the movable plate and the elasticity of the movable plate itself. It is possible to further improve the effect of preventing impact and abnormal noise when inputting amplitude vibration.

  In addition, the corrugated uneven surface according to this aspect is, for example, (1) in addition to an aspect in which the movable plate has a corrugated shape as a whole by attaching corrugated unevenness having the same phase on the upper and lower surfaces of the movable plate ( 2) Including an aspect in which the thick and thin portions are alternately connected to the movable plate by providing wavy irregularities in opposite phases on the upper and lower surfaces of the movable plate. 3) A mode in which only one of the upper and lower surfaces of the movable plate is wavyly uneven and the other surface is a substantially flat surface is also included.

(Aspect 9 of the present invention)
A feature of aspect 9 of the present invention is that, in the fluid-filled vibration isolator according to any of aspects 1 to 8 of the present invention, with respect to the contact surface of the movable plate to the contact portion, This is because the elastic small protrusion for buffering is integrally formed.

  In such a mode, when the movable plate hits the partition member, the impact is absorbed by the small elastic protrusion, and the vibration level relating to the hitting sound is advantageously reduced.

(Aspect 10 of the present invention)
A feature of the tenth aspect of the present invention is that in the fluid-filled vibration isolator according to any one of the first to ninth aspects of the present invention, the second mounting member has a substantially cylindrical shape, and the second mounting member One of the second mounting members is formed by the main body rubber elastic body, wherein the first mounting member is arranged separately on one opening side of the member, and the first mounting member and the second mounting member are connected to each other. The opening is covered fluid-tightly and the other opening of the second mounting member is covered fluid-tightly by the flexible membrane, while the partition member is fixedly supported by the second mounting member. At least, the pressure receiving chambers on both sides of the partition member are disposed between the opposing surfaces of the main rubber elastic body and the flexible membrane so as to spread in the direction perpendicular to the axis of the second mounting member. The equilibrium chamber is formed, and the second intake is interposed between the pressure receiving chamber and the equilibrium chamber. And to spread in the direction perpendicular to the axis of the member disposing the movable plate, in that the opposition spaced apart from the the movable plate abutment in the axial direction of the partition member.

  In this aspect, the pressure receiving chamber and the equilibrium chamber can be efficiently formed on both sides of the partition member provided with the movable plate, and a compact fluid-filled vibration isolator is realized as a whole. As a result, for example, the present invention is also preferably used for an engine mount for automobiles and the like that tend to be limited in installation space.

  As is apparent from the above description, in the fluid-filled vibration isolator having the structure according to the present invention, the movable plate and the partition member have at least one abutment surface as a low friction surface. And the sliding friction between the partition members is reduced. As a result, when the movable plate and the partition member are separated from the form in which they are in contact with each other, the generation of abnormal noise due to the stick-slip phenomenon or the like is effectively suppressed.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described. 1 and 2 show an automobile engine mount 10 as an embodiment of the present invention. The engine mount 10 has a structure in which a first mounting bracket 12 as a first mounting member and a second mounting bracket 14 as a second mounting member are connected by a main rubber elastic body 16. The engine mount 10 has the first mounting bracket 12 attached to the power unit side, while the second mounting bracket 14 is attached to the body, so that the power unit is mounted on the body with other engine mounts (not shown). It is designed to support vibration isolation in cooperation. Further, in such a mounted state, the mount 10 is provided with the first mounting bracket 12 and the second mounting bracket 14 as the main rubber elastic body 16 is elastically deformed by the input of the shared load of the power unit. 1 is moved relatively close to the vertical direction in FIG. 1 by a predetermined amount, and the main vibration to be damped is between the first mounting bracket 12 and the second mounting bracket 14 in FIG. It is input in a substantially vertical direction. In addition, the engine mount 10 of this embodiment has the mount center axis (the center axis of the first and second mounting brackets 12 and 14) in a substantially vertical direction as shown in FIG. Therefore, in the following description, unless otherwise specified, the vertical direction in FIG. 1 is the vertical direction.

  More specifically, the first mounting member 12 has a substantially disk shape, and a mounting bolt 18 that protrudes upward (upward in FIG. 1) is fixed to the center portion thereof. In addition, a holding fitting 20 is fixed to the lower surface of the first mounting fitting 12 on the central axis thereof. The holding metal fitting 20 includes a tapered peripheral wall portion that gradually expands toward the upper opening, and is fixed to the lower surface of the first mounting metal 12 at the opening edge.

  On the other hand, the second mounting bracket 14 has a large-diameter, generally annular shape, and is spaced downward (downward in FIG. 1) on the same central axis as the first mounting bracket 12. . In addition, the second mounting bracket 14 has a structure in which a fitting tube portion 24 that protrudes downward in the axial direction from the outer peripheral edge portion of the substantially annular plate-shaped rubber fixing portion 22 is integrally formed. ing. The inner peripheral portion of the rubber adhering portion 22 has a tapered inclined shape that is gradually inclined downward in the axial direction toward the center.

  A main rubber elastic body 16 is disposed between the opposing surfaces of the first mounting bracket 12 and the second mounting bracket 14. The main rubber elastic body 16 has a large-diameter, generally frustoconical shape, and a large hollow recess 26 is formed at the center thereof. The circular recess 26 is a bottomed reverse circular hole that gradually expands in the downward direction and opens to the end surface on the large diameter side of the main rubber elastic body 16. By forming the circular recess 26, the circular recess 26 is formed. The main rubber elastic body 16 has a thick, generally inverted cup shape as a whole.

  The first mounting bracket 12 is superimposed on the small diameter side end surface of the main rubber elastic body 16 in the axial direction, and the first mounting bracket 12 is fixed to the lower surface of the first mounting bracket 12 by welding or the like. A main rubber elastic body 16 is vulcanized and bonded to the mounting bracket 12. The main rubber elastic body 16 is also filled between the first mounting member 12 and the holding member 20. Further, the rubber fixing portion 22 of the second mounting bracket 14 is vulcanized and bonded to the large-diameter side end portion of the main rubber elastic body 16 in a substantially embedded state in a form inserted from the outer peripheral surface. In short, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14.

  In addition, a substantially annular plate-shaped reinforcing metal fitting 28 is fixed to an axially intermediate portion of the main rubber elastic body 16 which is formed in a thick cylindrical shape, and the spring characteristics of the main rubber elastic body 16 are adjusted. Further, as shown in FIG. 1, the second mounting bracket 14 covers the entire lower surface of the rubber fixing portion 22 and the inner peripheral surface of the fitting tube portion 24 so as to cover the entire seal rubber layer 30. Are integrally formed with the main rubber elastic body 16 and attached.

  Further, in the integrally vulcanized molded product of the main rubber elastic body 16 having the first and second mounting brackets 12 and 14, a partition as a partition member is formed from the axially lower opening side of the second mounting bracket 14. A metal fitting 32 and a diaphragm 34 as a flexible film are assembled.

  The partition metal fitting 32 has a thick, substantially disk shape, and is formed using a hard material such as a metal material or a synthetic resin material, and extends in a direction perpendicular to the axis so as to be a second attachment metal fitting. 14 is fitted in the fitting cylinder portion 24. Then, the upper surface and the outer peripheral surface of the outer peripheral portion of the partition fitting 30 are fluid-tightly overlapped with the rubber fixing portion 22 and the fitting cylinder portion 24 of the second attachment fitting 14 via the seal rubber layer 30.

  The diaphragm 34 is formed of a thin, substantially disk-shaped rubber elastic film that is easily deformed by providing a sufficient slack in the central portion. Further, the outer peripheral edge of the diaphragm 34 is vulcanized and bonded to a substantially annular fitting 36. The fitting 36 has a structure in which a cylindrical fixed tube portion 40 protruding upward from an outer peripheral edge portion thereof is integrally formed with a support portion 38 that expands in a substantially annular shape in a direction perpendicular to the axis. . The outer peripheral edge portion of the diaphragm 34 is vulcanized and bonded to the inner peripheral edge portion of the support portion 38. In addition, the fixed cylinder part 40 is extrapolated to the fitting cylinder part 24 of the second mounting bracket 14, and the fixed cylinder part 40 is subjected to diameter reduction processing such as an eight-way drawing. Thus, the fixed cylinder portion 40 of the fitting metal fitting 36 is externally fixed to the fitting cylinder portion 24 in a form in which the support portion 38 of the fitting metal fitting 36 is in contact with the lower surface of the outer peripheral portion of the partition fitting 32. Yes. The space between the fixed tube portion 40 and the fitting tube portion 24 is fluid-tightly sealed with a seal rubber layer 42 formed on the fixed tube portion 40.

  As a result, the opening portion of the circular recess 26 formed in the main rubber elastic body 16 that is opened downward through the central hole of the second mounting bracket 14 is covered with the diaphragm 34 in a fluid-tight manner. An incompressible fluid is sealed in a region between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 34 that is formed using the circular recess 26 and is sealed with respect to the external space. Thereby, a fluid enclosing region is defined. As such a sealed fluid, for example, water, alkylene glycol, polyalkylene glycol, silicone oil or the like is employed. In order to effectively obtain a vibration-proofing effect based on the resonance action of the fluid, for example, 0.1 Pa · s or less. It is desirable to employ a low viscosity fluid. The incompressible fluid is sealed by, for example, assembling the partition metal fitting 32 and the diaphragm 34 to the integrally vulcanized molded product of the main rubber elastic body 16 provided with the first and second attachment fittings 12 and 14. It is realized by performing in the inside.

  Further, the fluid sealing region is divided into two in the vertical direction by the partition metal fitting 32 being disposed so as to extend in the direction perpendicular to the axis. Accordingly, a part of the wall portion is formed of the main rubber elastic body 16 on one side in the axial direction (upper side in FIG. 1) sandwiching the partition metal 32, and the first mounting metal 12 and the second A pressure receiving chamber 44 is formed in which pressure fluctuations are caused by elastic deformation of the main rubber elastic body 16 when vibration is input between the mounting brackets 14. On the other hand, on the other side in the axial direction (lower in FIG. 1) across the partition metal fitting 32, a part of the wall portion is constituted by a diaphragm 34, and the volume can be easily changed based on the elastic deformation of the diaphragm 34. An allowable equilibrium chamber 46 is formed.

  Further, as shown in FIGS. 3 to 5, the partition metal fitting 32 is formed with a concave groove 48 that is open to the upper surface at the outer peripheral portion and continuously extends in the circumferential direction. A tunnel-like passage is formed by fluid-tightly covering with the rubber fixing portion 22 of the second mounting bracket 14. In the present embodiment, the concave groove 48 is formed by reciprocating in the circumferential direction on a portion of approximately 3/4 of the circumference of the partition metal 32, and on the circumference where the concave groove 48 is not formed. A hollow portion is formed in a portion extending over substantially a quarter of the circumference, and is covered with a rubber fixing portion 22 in a fluid-tight manner like the concave groove 48.

  In addition, the concave groove 48 is covered with the second mounting bracket 14 (rubber fixing portion 22) via the seal rubber layer 30, so that an orifice passage 50 filled with an incompressible fluid is formed. In addition, one end of the orifice passage 50 extends radially inward from the inner peripheral edge of the rubber fixing portion 22 of the second mounting member 14, and is partitioned on the inner peripheral side of the rubber fixing portion 22. It is connected to the pressure receiving chamber 44 through a communication hole 52 formed in the upper surface of the metal fitting 32. Further, the other end portion of the orifice passage 50 is connected to the equilibrium chamber 46 through a communication hole 54 penetrating the bottom wall portion of the concave groove 48 in the partition metal fitting 32. Thereby, the pressure receiving chamber 44 and the equilibrium chamber 46 are communicated with each other through the orifice passage 50.

  Therefore, at the time of vibration input, relative pressure fluctuation is induced between the pressure receiving chamber 44 in which pressure fluctuation is caused and the equilibrium chamber 46 in which volume change is allowed based on the deformation of the diaphragm 34. Fluid flow through the orifice passage 50 occurs between 44 and 46. As a result, the vibration isolating effect based on the fluid action such as the resonance action of the fluid flowing through the orifice passage 50 between the pressure receiving chamber 44 and the equilibrium chamber 46 is vibration in the axial direction (up and down in FIG. 1). It has come to be demonstrated against.

  In particular, in the present embodiment, the resonance frequency of the fluid that is allowed to flow through the orifice passage 50 exhibits an effective anti-vibration effect against low-frequency large-amplitude vibration of about 10 Hz such as a shake based on the resonance action of the fluid. Is tuned to be. The tuning of the resonance frequency is realized by changing the setting of the cross-sectional area and the length of the orifice passage 50, for example, while considering the rigidity of the wall springs of the pressure receiving chamber 44 and the equilibrium chamber 46.

  Further, a circular central recess 56 that opens upward is formed in the central portion of the partition metal 32, and a lid plate metal 58 is disposed from above the central recess 56. As shown in FIG. 6, the lid plate metal 58 has a thin, substantially flat plate shape, and is inserted through a plurality of (three in this embodiment) through holes 60 that are spaced apart in the circumferential direction. On the other hand, the axial projection 62 projecting from the partition metal 32 is inserted and caulked, or a fixing bolt (not shown) is inserted into the insertion hole 60 and screwed to the partition metal 32. And so on. Thereby, the lid plate metal 58 is positioned and arranged mutually in the circumferential direction with the partition metal 32 and is fixed to the partition metal 32 so as to cover the central recess 56. In addition, an accommodation space 64 that extends in a substantially disc shape is formed between the central recess 56 and the lid plate fitting 58 in the partition fitting 32.

  In the accommodation space 64, an elastic rubber plate 66 as a movable plate is accommodated. As shown in FIG. 7, the elastic rubber plate 66 has a substantially disk shape. The maximum plate thickness dimension T of the elastic rubber plate 66 is smaller than the height dimension L of the storage space 64 as shown by a two-dot chain line in FIG. Under the state of being positioned at the center in the space 64, a gap extending across the entire inner surface of the accommodation space 64 is formed around the entire elastic rubber plate 66. Therefore, the elastic rubber plate 66 is allowed to be freely displaced while floating in the accommodation space 64 by a stroke corresponding to the size of the gap.

  The elastic rubber plate 66 of the present embodiment includes a substantially disc-shaped central flat plate portion 68 as a flat plate-like portion and a substantially annular plate-shaped outer peripheral annular portion 70 that extends continuously in the circumferential direction at the outer peripheral edge portion. have.

  The central flat plate portion 68 extends in a circular shape with a substantially constant thickness on the central axis of the elastic rubber plate 66, and a plurality of buffer lip protrusions are integrally formed on both the upper and lower surfaces thereof. Yes. The buffer lip protrusion includes (a) an annular first buffer lip protrusion 72 that continuously extends in the circumferential direction in the radial direction and (b) a radial direction from the vicinity of the central axis toward the radially outward direction. It is configured to include eight independent second buffer lip protrusions 74 extending and (c) an annular third buffer lip protrusion 76 extending continuously in the circumferential direction on the outer peripheral edge.

  Further, the outer peripheral annular portion 70 has an inner diameter dimension larger than the outer diameter dimension of the central flat plate portion 68 and is positioned so as to surround the central axis of the central flat plate portion 68 substantially concentrically. Further, the central flat plate portion 68 and the outer peripheral annular portion 70 are integrated with each other by a thin connecting portion 78 extending in a substantially annular shape in a direction perpendicular to the axis at a substantially central portion in the plate thickness direction (up and down in FIG. 8). Connected. In other words, the elastic rubber plate 66 has a pair of annular recesses 80, 80 extending continuously in the circumferential direction at portions on the upper and lower surfaces thereof that are separated from the outer peripheral edge by a predetermined distance radially inward. The inner peripheral side is a central flat plate portion 68 and the outer peripheral side is an outer peripheral annular portion 70 with the connecting portion 78 thinned by the hollow portions 80, 80 interposed therebetween.

  In addition, on the upper and lower surfaces of the outer peripheral annular portion 70, there are annular fourth buffer lip protrusions 82 and fifth buffer lip protrusions 84 extending continuously in the circumferential direction at the inner peripheral edge portion and the outer peripheral edge portion, respectively. It is integrally formed.

  Furthermore, the thickness of the outer peripheral annular portion 70 including the fourth and fifth buffer lip protrusions 82 and 84 is such that the central flat plate-shaped portion including the first, second and third buffer lip protrusions 72, 74 and 76. The thickness is smaller than 68. Furthermore, the outer peripheral annular portion 70 is a corrugated portion having a shape that is curved and undulated as a whole in a circumferential direction such that it undulates in the plate thickness direction (up and down in FIGS. 8 and 9). That is, the outer peripheral annular portion 70 is changed so that the center position in the thickness direction swings up and down in the circumferential direction without substantially changing the shape and size of the radial cross section. In particular, in the present embodiment, as shown in FIG. 9, the center line and the upper and lower surfaces of the outer peripheral annular portion 70 have a substantially sinusoidal wave shape in the circumferential direction with a constant cycle, and one cycle thereof. Is 90 degrees in the circumferential direction, and the upper and lower surfaces are generally smooth curved surfaces. As is apparent from this, in this embodiment, the upper and lower surfaces of the elastic rubber plate 66 on which the respective buffer lip protrusions 72, 74, 76, 82, 84 are formed have wave-like irregularities that expand in a substantially wave shape with continuous irregularities. It is considered as a surface.

  Further, in the present embodiment, the outer peripheral annular portion 70 is gradually thinned toward the outer peripheral side, and the upper and lower surfaces 86, 88 of the outer peripheral annular portion 70 are radially inclined surfaces having substantially the same angle. Has been. And since the connection part 78 is thin, when the outer periphery annular part 70 is displaced or deformed in a swinging manner with the connection part 78 as a fulcrum, only the outer peripheral edge part does not come into contact. In this case, they are in contact with each other from the inner peripheral edge portion or are substantially in contact with each other at the same time. As a result, in the region until the outer peripheral annular portion 70 comes into contact with the inner surface of the accommodation space 64, it is possible to displace within the largest swing angle range.

  Furthermore, in the present embodiment, the position of the outer peripheral annular portion 70 that is the lowest end, that is, the central portion in the circumferential direction of the convex portion toward the lower side, at the left and right end positions in FIG. The inner peripheral edge portion of the lower surface 88 is positioned on substantially the same plane as the lower surface of the central flat plate portion 68. Further, the position of the outermost annular portion 70 is the uppermost position, that is, the central portion in the circumferential direction of the upward convex portion, and the inner peripheral edge portion of the upper surface 86 of the outer circumferential annular portion 70 is the central position in FIG. The central flat plate portion 68 is positioned on the same plane as the upper surface.

  The first, second, and third buffer lip protrusions 72, 74, and 76 projecting from the central plate-shaped portion 68, and the fourth and fifth buffer lip protrusions projecting from the outer peripheral annular portion 70. The protrusion heights 82 and 84 are substantially the same.

  Therefore, in a state where the elastic rubber plate 66 is not elastically deformed by an external force, the first, second and third buffer lip protrusions projecting from the lower surface of the central plate-like portion 68 on the lower surface thereof. 72, 74, 76 and the fourth buffering lip protrusion 82 projecting from the lower surface 88 of the outer peripheral annular portion 70 at the lowest position (left and right end positions in FIG. 9). The tip is located on the same plane perpendicular to the axis. Further, on the upper surface of the elastic rubber plate 66, the projecting tip portions of the first, second and third buffering lip protrusions 72, 74 and 76 projecting from the upper surface of the central flat plate-shaped portion 68 and the outer ring shape The projecting tip at the uppermost position (the center position in FIG. 9) of the fourth buffering lip protrusion 82 projecting from the upper surface 86 of the portion 70 is positioned on the same axis perpendicular plane. .

  Accordingly, when the elastic rubber plate 66 is greatly displaced in the axial direction (vertical direction) within the accommodation space 64, the protruding tip portions of the first, second and third buffering lip protrusions 72, 74, 76 and the first The protruding tip portions at specific positions on the circumference of the four buffer lip protrusions 82 are brought into contact with the lower surface and the upper surface of the accommodation space 64 at substantially the same time. As is clear from the above description, in this embodiment, the elastic small protrusion for buffering is configured to include the first to fifth buffering lip protrusions 72, 74, 76, 82, 84.

  In the present embodiment, the thickness of the outer circumferential annular portion 70 is made thinner as it goes to the outer circumferential side, and the outer circumferential annular portion 70 is curved up and down in a corrugated shape in the circumferential direction. The fifth buffering lip protrusion 84 projecting from the outer peripheral edge of the outer peripheral annular portion 70 is a portion located on the lowermost surface 88 of the outermost annular portion 70 and a portion located on the uppermost surface 86 of the lowermost end, In other words, at the center portions in the circumferential direction of the recesses on the upper surface 86 and the lower surface 88, there is almost no contact with the inner surface of the accommodation space 64. Therefore, in the present embodiment, the fifth buffer lip protrusions 84, 84 protrude in both the portion located on the lowermost surface 88 of the outermost annular portion 70 and the portion located on the uppermost surface 86 of the lowermost end. The height is reduced, and weight reduction and cost reduction are achieved based on a decrease in the rubber material.

  In addition, through holes 90 and 92 penetrating in the axial direction (up and down in FIG. 1) are formed in the bottom wall portion of the central recess 56 of the cover plate metal 58 and the partition metal fitting 32 constituting the upper and lower inner surfaces of the accommodation space 64. ing. The through holes 90 and 92 are positioned to open over substantially the entire upper and lower inner surfaces of the accommodation space 64, and in particular, the central flat plate portion 68 positioned at the central portion of the elastic rubber plate 66 and the outer periphery positioned at the outer peripheral portion. It is formed so as to open in a region opposite to the annular portion 70. As a result, the upper surface of the elastic rubber plate 66 accommodated and disposed in the accommodation space 64 is exposed to the pressure receiving chamber 44 through the through hole 90 of the lid plate fitting 58, while the lower surface of the elastic rubber plate 66 is exposed to the central recess 56. It is exposed to the equilibrium chamber 46 through a through hole 92 in the bottom wall.

  Therefore, the internal pressure of the pressure receiving chamber 44 and the equilibrium chamber 46 is exerted on the elastic rubber plate 66 on the upper surface and the lower surface, and the elastic rubber plate is based on the pressure difference between the pressure receiving chamber 44 and the equilibrium chamber 46 when vibration is input. A displacement in the plate thickness direction is caused with respect to 66. Then, based on the displacement of the elastic rubber plate 66 in the axial direction, the fluid flow through the through holes 90 and 92 of the lid plate metal 58 and the partition metal 32 is generated, so that the resonance action or pressure receiving chamber 44 of the fluid is generated. The hydraulic pressure absorption action based on releasing the pressure fluctuation to the equilibrium chamber 46 is exhibited, and the low dynamic spring effect with respect to the input vibration is obtained.

  The allowable stroke in the vertical direction (plate thickness direction) within the accommodation space 64 of the elastic rubber plate 66 is the amplitude of the input vibration to be vibrated, the effective piston diameter in the pressure receiving chamber 44 of the engine mount 10, the elastic rubber. It is appropriately adjusted depending on the size of the plate 66 and the like. In this embodiment, when an amplitude vibration of ± 0.5 to 2.0 mm corresponding to an engine shake is applied between the first mounting bracket 12 and the second mounting bracket 14, the elastic rubber plate 66 is moved. In the region where the elastic rubber plate 66 does not contact the inner surface of the accommodation space 64 when the medium or small amplitude vibration of ± 0.25 mm or less corresponding to idling vibration or traveling noise is input. The size of the gap between the opposing surfaces of the upper and lower surfaces of the elastic rubber plate 66 and the upper and lower inner surfaces of the accommodation space 64 is set so that the displacement is allowed.

  When a large amplitude vibration is input between the first mounting bracket 12 and the second mounting bracket 14, the elastic rubber plate 66 is greatly displaced in the thickness direction in accordance with the pressure fluctuation in the pressure receiving chamber 44. Due to the deformation, the upper surface of the elastic rubber plate 66 is brought into contact with the lower surface of the cover plate metal 58 constituting the upper surface of the accommodation space 64, or the lower surface of the elastic rubber plate 66 constitutes the lower surface of the accommodation space 64. Or abutted against the bottom surface of the central concave portion 56 of the partition metal fitting 32. Thereby, the displacement amount of the elastic rubber plate 66 is limited by the contact of the lid plate metal 58 or the bottom of the partition metal 32. As is clear from this, in the present embodiment, the abutting portion provided on the partition member so as to be spaced from and opposed to at least one side of the elastic rubber plate 66 is the lid plate metal 58 or the partition metal 32. The bottom portion of the (center recess 56) is included.

Therefore, the elastic rubber plate 66 of the present embodiment is formed using self-lubricating rubber. The self-lubricating rubber is not particularly limited, and a known material obtained by blending a rubber elastic body with a lubricant is employed. Specifically, rubber elastic bodies include, for example, styrene-butadiene rubber (SBR), butadiene rubber (BR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene-diene rubber (EPDM), butyl rubber (IIR). ), Synthetic rubber such as chlorinated butyl rubber (Cl-IIR), isoprene rubber (IR), and natural rubber (NR). In particular, considering that it is used as a base material for the elastic rubber plate 66 of the engine mount 10, NR, SBR, BR, etc. having excellent strength are suitably employed. As the lubricant, for example, unsaturated fatty acid amide, silicone oil or the like is employed. The unsaturated fatty acid amide is represented by the general formula: “RCONH ₂ ” or “RCONHR′NHCOR ″” (R and R ″ are unsaturated fatty acid alkyl groups, and R ′ is an alkylene group). And erucic acid amide, N-oleyl stearic acid amide, ethylenebisoleic acid amide, dioleyl adipic acid amide and the like.

  That is, since the elastic rubber plate 66 is formed of self-lubricating rubber, a lubricant such as an unsaturated fatty acid amide oozes on the surface of the rubber elastic body, so that substantially the entire outer peripheral surface of the elastic rubber plate 66 is It is a low friction surface that has been subjected to a low friction treatment.

  In particular, in the present embodiment, the friction coefficient μ at each contact surface of the elastic rubber plate 66 and the lid plate metal 58 or the partition metal 32 is μ ≦ 1, preferably 0.01 ≦ μ, in the incompressible fluid. The material, shape, size, and the like of the low friction surface (upper and lower surfaces) of the elastic rubber plate 66 are set so that ≦ 1.

  In the automotive engine mount 10 of the present embodiment having the above-described structure, vibrations in a substantially axial direction are input between the first mounting bracket 12 and the second mounting bracket 14 when mounted on the vehicle. If it is a small amplitude vibration in the middle to high frequency range corresponding to an idling vibration of about ± 0.1 to 0.25 mm or a traveling noise of about ± 0.01 to 0.05 mm, it is elastic. A hydraulic pressure absorbing action based on the displacement of the rubber plate 66 is exhibited. That is, based on the fact that the elastic rubber plate 66 is displaced up and down within a movable range that is allowed by a gap provided between the housing space 64 when such small amplitude vibration in the middle to high frequency range is input. The substantial fluid flow between the pressure receiving chamber 44 and the equilibrium chamber 46 through the through holes 90 and 92 is allowed through the accommodation space 64, so that the pressure fluctuation of the pressure receiving chamber 44 is transferred to the equilibrium chamber 46. Escaped. As a result, a significant increase in the dynamic spring caused by clogging as an anti-resonance phenomenon of the orifice passage 50 is avoided, and good vibration isolation performance is exhibited.

  On the other hand, when the vibration input between the first mounting bracket 12 and the second mounting bracket 14 has a relatively large amplitude in the low frequency range, for example, a normal travel shake of ± 0.5 to 1.0 mm. In the case of the above, or in the case of a shake when overcoming a step of about ± 1.0 to 2.0 mm, the pressure fluctuation in the pressure receiving chamber 44 is changed only by the displacement within the movable range of the elastic rubber plate 66 in the accommodation space 64. Cannot be absorbed. That is, the upper and lower surfaces of the elastic rubber plate 66 repeatedly abut (hit) against the bottoms of the cover plate metal 58 and the partition metal 32 that form the upper and lower inner surfaces of the accommodation space 64. Then, when the elastic rubber plate 66 hits the lid plate metal 58 or the partition metal 32, the through holes 90 and 92 formed therein are narrowed or substantially closed by the elastic rubber plate 66. As a result, a relative pressure fluctuation is effectively induced between the pressure receiving chamber 44 and the equilibrium chamber 46, and a fluid flow through the orifice passage 50 is generated based on the relative pressure fluctuation, so that the orifice An anti-vibration effect based on the resonance action of the fluid flowing through the passage 50 is exhibited.

  Therefore, the elastic rubber plate 66 according to the present embodiment is formed of self-lubricating rubber, and the contact surface with respect to the contact portion of the partition metal fitting 32 or the cover metal plate 58 is a low friction surface. Based on the fact that the coefficient of friction between the elastic rubber plate 66 and the abutting portion is reduced, the impact especially when moving away from the abutting portion is advantageously suppressed. Further, when the elastic rubber plate 66 strikes against the abutting portion, the friction coefficient of both the abutting surfaces is reduced so that the impact in the sliding direction is released and the elastic rubber plate 66 is deformed. It is also expected that the generated impact will be reduced by the function of impact absorption by the accompanying elasticity and damping. Therefore, the impact caused by repeated contact / separation of the elastic rubber plate 66 with the contact portion is reduced, and the desired noise reduction effect is advantageously obtained.

  In addition, particularly in the present embodiment, when the elastic rubber plate 66 abuts against the bottom of the central recess 56 of the partition metal fitting 32, the outer peripheral annular portion 70 is curved at the top of the circumference curved so as to wave up and down. Only the lower surface of the lower end first comes into contact at a total of four locations on the circumference. Thereafter, when the hydraulic pressure acting on the elastic rubber plate 66 from the upper surface is further increased, the outer peripheral annular portion 70 is gradually elastically deformed by an external force (pressure) that increases in addition to the kinetic energy at the time of contact. The contact area gradually increases from the initial contact position of the lowermost bottom surface on the circumference toward both sides in the circumferential direction.

  Further, when the outer peripheral annular portion 70 of the elastic rubber plate 66 contacts the lid plate metal 58, similarly, the upper surface of the uppermost end on the periphery of the outer peripheral annular portion 70 contacts first, and then the outer peripheral circle As the amount of elastic deformation of the annular portion 70 increases, the contact surface gradually spreads on both sides in the circumferential direction, increasing the contact area. That is, the outer peripheral annular portion 70 strikes against the partition fitting 32 and the cover plate fitting 58 constituting the wall portion of the accommodation space 64 even in portions other than the center of the convex portion on each of the upper and lower surfaces.

  When such an abutting state occurs, when the elastic rubber plate 66 abuts, the contact of the elastic rubber plate 66 is based on the damping action accompanying the elastic deformation of the outer circumferential annular portion 70 or the absorption action of the abutting energy. The impact at the time of contact can be effectively mitigated, and as a result, the generation of abnormal noise and impact due to the contact of the elastic rubber plate 66 with the partition fitting 32 or the like can be suppressed.

  In particular, in the present embodiment, a small impact when the elastic rubber plate 66 abuts against the partition fitting 32 or the like is also absorbed by the elastic deformation of the first to fifth buffer lip protrusions 72, 74, 76, 82, 84. Therefore, a more effective noise and impact mitigation effect can be exhibited.

  Here, in the present embodiment, not only the small buffer lip protrusion but also the elastic deformation of the elastic rubber plate 66 main body having a predetermined thickness is utilized to exhibit the energy absorption when the elastic rubber plate 66 contacts the partition fitting 32. Therefore, it is possible to effectively absorb and reduce the impact at the time of large contact.

  In addition, in the present embodiment, shock absorption at the time of contact is made at the outer peripheral edge portion (outer peripheral annular portion 70) of the elastic rubber plate 66, which is particularly free displacement end, so that the displacement speed at the time of hitting is most likely to be greatest. Since the wave-like portion that exhibits the action is formed, the impact absorbing effect at the time of contact by the wave-like portion can be more effectively exhibited.

  In addition, in the present embodiment, a thin connecting portion 78 is formed near the outer peripheral edge of the elastic rubber plate 66 so that the outer peripheral annular portion 70 can be deformed and displaced to some extent independently of the central flat plate portion 68. This avoids the displacement and elastic deformation of the outer annular portion 70 being unnecessarily constrained by the central flat plate portion 68, and advantageously causes the elastic deformation when the outer annular portion 70 abuts. It can be tightened. Therefore, the impact absorbing effect at the time of contact as described above accompanying the elastic deformation of the outer peripheral annular portion 70 can be more effectively exhibited.

  Incidentally, the result of having measured the anti-vibration performance about the engine mount 10 for motor vehicles made into the structure according to the above-mentioned embodiment is shown in FIG. In such measurement, the output side (second mounting bracket 14 side) when an axial excitation force is applied to the first mounting bracket 12 with the second mounting bracket 14 fixedly supported. Based on the data of the transmission force detected by the load cell. FIG. 10 shows the result of frequency analysis of the detected data by fast Fourier transform. The results measured for each vibration input (vibration) at a frequency of 10 Hz and an excitation amplitude of ± 0.2 mm, ± 1.0 mm, and ± 4.0 mm are respectively shown in Examples: A-1 and A−. 2, A-3 is shown in the figure.

  Further, as a comparative example, the shape and size are substantially the same as those of the elastic rubber plate 66 of the present embodiment, but the low friction treatment is performed based on being formed of NR or the like, that is, not formed of self-lubricating rubber. An elastic rubber plate that has not been applied is employed, and an engine mount is prepared in which the other members are the same as those of the above-described embodiment. And also about the engine mount as this comparative example, the same test as the above-mentioned engine mount 10 of this embodiment was implemented. The measurement results of this comparative example are also shown in FIG. The results measured for each vibration input (vibration) at a frequency of 10 Hz and an excitation amplitude of ± 0.2 mm, ± 1.0 mm, and ± 4.0 mm were respectively compared with Comparative Examples: B-1 and B−. 2 and B-3 in the figure.

  From the results shown in FIG. 10 as well, in the engine mount 10 of the embodiment that employs the elastic rubber plate 66 made of a self-lubricating rubber material as described above, the elastic rubber plate 66 comes into contact with the partition fitting 32 repeatedly. It can be understood that the value of the dynamic load representing the impact considered to be generated can be suppressed to be smaller than that of the engine mount of the comparative example structure that does not employ the self-lubricating rubber material.

  In addition, the relationship between Example: A-1 and Comparative Example B-1, the relationship between Example: A-2 and Comparative Example B-2, and the relationship between Example: A-3 and Comparative Example B-3. When compared with each other, it is recognized that the impact reduction effect of the present invention is more effectively exhibited as the amplitude of the input vibration is smaller.

  This is because, when the amplitude of the input vibration is large, the impact when the elastic rubber plate 66 strikes the partition metal fitting 32 becomes dominant, whereas when the amplitude of the input vibration is small, the elastic rubber plate 66 is separated from the partition metal fitting 32. The impact when pulled apart is considered to be dominant. Therefore, the configuration in which the contact surface between the elastic rubber plate 66 and the partition fitting 32 is reduced in friction according to the present invention is more effective than the impact relaxation when the elastic rubber plate 66 is brought into contact with the partition fitting 32. It can be confirmed that it is more effective for mitigating the impact at the time of separation from the 66 partition fittings 32.

  As mentioned above, although one embodiment of the present invention has been described in detail, the present invention is not limited in any way by the specific description in the embodiment, and various changes, modifications, and modifications based on the knowledge of those skilled in the art. Needless to say, the present invention can be implemented in a mode with improvements and the like, and all such modes are included in the scope of the present invention without departing from the gist of the present invention.

  For example, in the above-described embodiment, the buffer lip protrusions 72, 74, 76, 82, and 84 are integrally formed on both surfaces of the elastic rubber plate 66. However, these buffer lip protrusions are not necessarily required, and as illustrated. In addition to the protrusion-shaped buffer lip protrusions that continuously extend in the circumferential direction or the direction perpendicular to the axis, it is also possible to adopt a number of independent buffer-shaped protrusion lip protrusions.

  Further, the outer peripheral annular portion 70 does not need to have a continuous wavy shape over the entire circumference in the circumferential direction, for example, in a state where it is divided into a part or a plurality of locations on the circumference, A wavy portion may be formed.

  Further, even when the wave-like portion is formed on the outer peripheral edge of the elastic rubber plate 66, the thin connecting portion 78 is not necessarily required between the two.

  Furthermore, the waved portion of the elastic rubber plate 66 is not necessarily formed on the outer peripheral edge. Specifically, for example, as shown in FIGS. 11 and 12, it is possible to configure substantially the entire elastic rubber plates 94 and 96 as wave-like portions. In short, the elastic rubber plates 94 and 96 shown in FIG. 11 and FIG. 12 have a substantially constant thickness, but the entire elastic rubber plates 94 and 96 are wavy in one radial direction or circumferential direction. It is wavy and has a curved uneven shape that spreads continuously. In the present specification, in the description with reference to FIGS. 11 to 17, members and parts having substantially the same structure as those of the embodiment are denoted by the same reference numerals as those of the embodiment. Therefore, detailed description thereof will be omitted.

  Moreover, in the said embodiment, although the outer periphery annular part 70 in the elastic rubber plate 66 was made into the corrugated uneven surface which spreads substantially wave shape with the continuous unevenness | corrugation, for example, as shown in FIG. It is also possible to employ an elastic rubber plate 98 having smooth upper and lower surfaces without adopting it.

  Furthermore, in the above-described embodiment, the plate thickness dimension: T of the central flat plate portion 68 and the separation dimension in the plate thickness direction between the convex portion on the upper surface side and the convex portion on the lower surface side in the outer peripheral annular portion 70. (Waviness height dimension) is set to be substantially the same, whereby when the elastic rubber plate 66 is displaced in the axial direction and abuts against the partition metal fitting 32 and the cover metal fitting 58, the central flat plate-like portion 68 and Although the outer peripheral annular portion 70 comes into contact with each other substantially simultaneously, the central flat plate portion 68 and the outer peripheral annular portion 70 may come into contact sequentially from any one side.

  Specifically, the outer peripheral annular portion 70 that is a wave-shaped portion does not necessarily need to first contact the partition metal fitting 32 or the like. For example, as shown in FIG. Also, the uppermost positions of the upper and lower surfaces 86 and 88 (the most protruding points on the respective convex portions) are positioned inwardly in the plate thickness direction, and the outer peripheral ring shape comes into contact with the central flat plate portion 68. The part 70 may come into contact. Even with such a structure, when at least a large amplitude vibration is input and the outer peripheral annular portion 70 strikes the partition fitting 32 or the cover plate fitting 58 strongly, the corrugated outer annular portion is formed. The impact absorbing and mitigating action due to the elastic deformation accompanying the hitting of 70 can be effectively exhibited. 14 and the following FIGS. 15 to 17 are side views schematically showing a state in which the outer peripheral surface of the elastic rubber plate is viewed from the outside in the direction perpendicular to the axis.

  Alternatively, as shown in FIG. 15, the outer peripheral annular portion 70, which is a wave-like portion, comes into contact with the partition fitting 32 and the like only on one surface of the elastic rubber plate 66. May be. As a result, the effect of absorbing the impact accompanying the contact of at least one surface is effectively exhibited.

  Further, as shown in FIG. 16, the uppermost and lowermost positions of the upper and lower surfaces of the outer peripheral annular portion 70 that is a wave-shaped portion are arranged further outward in the plate thickness direction than the upper and lower surfaces of the central flat plate portion 68. You may make it project. By doing so, the outer peripheral annular portion 70 comes into contact with the partition fitting 32 and the like before the central flat plate-like portion 68, and the effect of absorbing the shock due to the elastic deformation of the outer peripheral annular portion 70 is more effectively exhibited. Can be done.

  Moreover, in the said embodiment, it was made into a corrugated board shape by attaching the corrugated unevenness | corrugation of the same phase on the upper and lower surfaces of the elastic rubber board 66 (outer periphery annular part 70), For example, FIG. 17 also shows. As shown in the figure, the elastic rubber plates 100 are alternately formed so that the thick portions 102 and the thin portions 104 are smoothly connected to each other in the width direction by providing wavy irregularities in opposite phases on the upper and lower surfaces. It is also possible to adopt.

  Furthermore, in the embodiment, the gap is formed around the entire elastic rubber plate 66 in a state where the elastic rubber plate 66 is positioned at the center of the allowable displacement range of the accommodation space 64. The rubber plate 66 may be assembled in a state in which the rubber plate 66 is elastically brought into contact with a part of the accommodation space 64 in the thickness direction, and further in a compressed state. In other words, even when the elastic rubber plate 66 is assembled in the plate thickness direction in contact with the accommodation space 64 or in a compressed state, a pressure difference is exerted on the upper and lower surfaces of the elastic rubber plate 66, so that the elasticity of the elastic rubber plate 66 is increased. Based on the deformation, the pressure absorbing action of the pressure receiving chamber 44 can be exhibited. In such an aspect, under the vibration input state, one surface of the elastic rubber plate 66 is spaced away from the abutting portion of the partition member and is opposed to the above-described embodiment. Accordingly, the effects of the present invention can be effectively exhibited as in the above embodiment. In addition, it is possible to more effectively suppress the impact of the elastic rubber plate 66 against the partition fitting 32 and the like by storing the elastic rubber plate 66 in the storage space 64 in a contact state or in a compressed state in advance. Become.

  Further, in the above embodiment, the low friction process in which the contact surface between the elastic rubber plate 66 and the partition metal fitting 32 is a low friction surface has been realized by using self-lubricating rubber for the elastic rubber plate 66. The invention is not limited to this. For example, the abutment surface of the partition metal fitting 32 on the elastic rubber plate 66 is a smooth surface with a surface roughness Ra ≦ 1.6 μm, preferably 0.5 μm ≦ Ra ≦ 1 in consideration of workability of the smoothing process. The low friction treatment described above may be realized by using a smooth surface of .6 μm. At that time, whether the elastic rubber plate 66 is formed using a self-lubricating rubber or a rubber material such as NR is not particularly limited.

  Further, in the above-described embodiment, the elastic rubber plate 66 can be displaced separately from the partition metal 32, and is accommodated in the accommodation space 64 of the partition metal 32, so that both sides of the elastic rubber plate 66 in the displacement direction are The amount of displacement on both sides of the elastic rubber plate 66 is limited by abutting against the abutting portion composed of the bottom of the partition metal fitting 32 and the lid plate metal fitting 58 each formed of the wall portion of the accommodation space 64. However, the present invention is not limited to this. For example, as shown in JP-A-4-321833, JP-A-6-129479, and the like, the outer peripheral edge of the elastic rubber plate is fixedly supported by a partition fitting, and the elastic rubber plate A mode in which displacement of the elastic rubber plate is allowed based on elastic deformation is also included in the technical scope of the present invention.

  In addition, the specific shape of the main rubber elastic body 16 and the specific structure and shape of the orifice passage 50 are appropriately changed in consideration of the vibration-proof characteristics required for the mount, the planned installation space, and the like. Of course, the present invention is not limited to the above embodiment.

  In addition, in the above-described embodiments, specific examples of applying the present invention to the engine mount 10 for automobiles have been described. However, the present invention can prevent various vibration bodies other than automobiles other than automobile body mounts and differential mounts. Needless to say, any of the vibration mounts can be applied.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view illustrating an automobile engine mount as an embodiment of the present invention. It is a plane explanatory view showing the engine mount in FIG. FIG. 2 is an explanatory plan view of a partition metal fitting constituting a part of the engine mount in FIG. 1. It is IV-IV sectional drawing in FIG. It is bottom surface explanatory drawing which shows the partition metal fitting in FIG. FIG. 2 is an explanatory plan view showing a cover plate metal fitting constituting a part of the engine mount in FIG. 1. It is a plane explanatory view which expands and shows the elastic rubber board which constitutes a part of engine mount in Drawing 1. It is VIII-VIII sectional drawing in FIG. FIG. 8 is a development view over a quarter circumference of the outer peripheral surface of the elastic rubber plate in FIG. 7. It is a graph which shows the result of having analyzed the frequency of the dynamic load detection data at the time of vibration input about the engine mount in FIG. It is a perspective explanatory view showing another structural example of an elastic rubber plate employed in an engine mount as one embodiment of the present invention. It is a perspective explanatory view showing another structural example of an elastic rubber plate employed in an engine mount as one embodiment of the present invention. It is a perspective explanatory view showing still another structural example of an elastic rubber plate employed in an engine mount as one embodiment of the present invention. It is explanatory drawing which expands and shows another structural example of the elastic rubber board employ | adopted as the engine mount as one Embodiment of this invention, Comprising: It is an expanded view of the outer peripheral surface corresponding to FIG. It is explanatory drawing which expands and shows another structural example of the elastic rubber board employ | adopted as the engine mount as one Embodiment of this invention, Comprising: It is an expanded view of the outer peripheral surface similar to FIG. FIG. 15 is an explanatory view showing, on an enlarged scale, still another structural example of the elastic rubber plate employed in the engine mount as one embodiment of the present invention, and is a developed view of the outer peripheral surface similar to FIG. 14. It is explanatory drawing which expands and shows another structural example of the elastic rubber plate employ | adopted as the engine mount as one Embodiment of this invention, Comprising: It is an expanded view of the outer peripheral surface similar to FIG. 1 shows the result of frequency analysis of dynamic load detection data at the time of vibration input with respect to an engine mount having the same basic structure as the engine mount in FIG. It is a graph.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automotive engine mount 12 1st attachment metal fitting 14 Second attachment metal fitting 16 Main body rubber elastic body 32 Partition metal fitting 34 Diaphragm 44 Pressure receiving chamber 46 Equilibrium chamber 50 Orifice passage 56 Central recessed part 58 Cover plate metal fitting 66 Elastic rubber plate

Claims (10)

A pressure receiving chamber in which a first mounting member and a second mounting member are connected by a main rubber elastic body, a part of the wall portion is configured by the main rubber elastic body, and pressure fluctuations are generated at the time of vibration input; and a wall portion Are formed of a flexible membrane and formed on both sides of the partition member supported by the second mounting member to enclose an incompressible fluid. The pressure receiving chamber and the equilibrium chamber are filled with an incompressible fluid, and an orifice passage is provided to communicate the pressure receiving chamber and the equilibrium chamber with each other, while a movable plate is disposed and supported with respect to the partition member, The pressure of the pressure receiving chamber is exerted on one surface of the movable plate, and the pressure of the equilibrium chamber is exerted on the other surface, so that a minute pressure fluctuation in the pressure receiving chamber at the time of vibration input is passed through the movable plate. Let it escape to the equilibrium chamber and absorb, and less of the movable plate Provided abutments also opposed position on one side of the partition member, the fluid filled type vibration damping device as displacement of the movable plate is restricted by the abutment of the abutting portion,
A fluid-filled vibration damping device, wherein the movable plate is formed of a rubber elastic plate, and a contact surface of at least one of the movable plate and the partition member is a low friction surface subjected to a low friction process. .   2. The fluid-filled vibration isolating apparatus according to claim 1, wherein the low friction surface has a friction coefficient μ at a contact surface between the movable plate and the partition member such that μ ≦ 1 in the incompressible fluid. apparatus.   The fluid-filled vibration isolator according to claim 1 or 2, wherein the movable plate is formed of self-lubricating rubber so that a contact surface of the movable plate is the low friction surface.   The contact surface of the partition member is a smooth surface having a surface roughness Ra ≦ 1.6 μm, so that the contact surface of the partition member is the low friction surface. Fluid-filled vibration isolator.   The fluid-filled type prevention according to any one of claims 1 to 4, wherein the contact surface of the partition member is a coating layer made of a low friction resin so that the contact surface of the partition member is the low friction surface. Shaker.   The movable plate is displaceable separately from the partition member, and the movable plate is accommodated in an accommodation space formed in the partition member, and both surfaces of the movable plate in the displacement direction are respectively separated from the partition member. The displacement amount to the both sides of this movable board is restrict | limited by contacting with the said contact part comprised by the wall part of the storage space of any one of Claim 1 thru | or 5 Fluid-filled vibration isolator.   6. The movable plate according to claim 1, wherein an outer peripheral edge of the movable plate is fixedly supported by the partition member, and displacement is allowed based on elastic deformation of the movable plate. The fluid-filled vibration isolator as described.   The fluid-filled vibration isolator according to any one of claims 1 to 7, wherein at least a part of a contact surface of the movable plate with respect to the contact portion is a corrugated uneven surface that spreads in a substantially wave shape with continuous unevenness.   The fluid-filled vibration isolator according to any one of claims 1 to 8, wherein an elastic small protrusion for buffering is integrally formed on a contact surface of the movable plate to the contact portion.   The second mounting member has a substantially cylindrical shape, and the first mounting member and the second mounting member are separated from each other on one opening side of the second mounting member. The main rubber elastic body to be coupled covers one opening of the second mounting member fluid-tightly, and the other opening of the second mounting member is fluid-tightly covered by the flexible film. On the other hand, the partition member is fixedly supported by the second mounting member and arranged so as to spread in the direction perpendicular to the axis of the second mounting member between the opposing surfaces of the main rubber elastic body and the flexible membrane. By forming, the pressure receiving chamber and the equilibrium chamber are formed on both sides of the partition member, and the second mounting member extends in the direction perpendicular to the axis between the pressure receiving chamber and the equilibrium chamber. The movable plate is disposed, and the movable plate and the contact portion are separated in the axial direction of the partition member. Fluid-filled vibration damping device according to any one of claims 1 to 9 opposition positions.

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