JP2005214352A - Fluid sealed type vibration isolating mount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid sealed type vibration isolating mount, securing the basic performance to enough efficiently exhibit pressure variation in a pressure receiving chamber, advantageously securing the axial spring rigidity to stably support an object member to be vibration-isolated, and advantageously obtaining the effect based on right-angled intended low spring characteristic by setting the right-angled spring characteristic to be soft. <P>SOLUTION: In a position deviated from the elastic center axis of a rubber elastic body 16, a first bore hole 58 opened in an inner surface facing to a pressure receiving chamber 36 and a second bore hole 62 opened in an outer surface exposed to the outside are respectively provided extending in the substantially axial direction. The first bore hole 58 and the second bore hole 62 are positioned opposite to each other at a space in the right-angled direction, with such a depth that one bottom 60 (64) is extended in the axial direction to exceed the other bottom 64 (60), whereby an elastic vertical wall 66 extended in the substantially axial direction is formed between the opposite surfaces in the right-angled direction of the first bore hole 58 and the second bore hole 62. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fluid-filled vibration-proof mount that obtains a vibration-proof effect by utilizing a vibration-proof characteristic that is exhibited based on the flow action of an incompressible fluid sealed inside. The present invention relates to a fluid-filled vibration-proof mount applied to an engine mount, a body mount, a differential mount, and the like.

  Conventionally, as a type of anti-vibration mount such as an anti-vibration support and an anti-vibration coupling body interposed between members constituting the vibration transmission system, fluid action such as resonance action of incompressible fluid enclosed inside There is known a fluid-filled vibration-proof mount that achieves a vibration-proof effect based on the above. Such an anti-vibration mount is, for example, as shown in Patent Document 1, in which a first mounting member and a cylindrical second mounting member spaced apart from the first mounting member are made of a main rubber elastic body. The second mounting member is connected to fluidly cover one opening of the second mounting member, and the other opening of the second mounting member is fluid-tightly covered with a flexible film. A partition member is disposed between the flexible membranes, and on both sides of the partition member, incompressible fluid is sealed, and the volume change is caused by the pressure receiving chamber to which vibration is input and the flexible membrane. An easily allowed equilibrium chamber is formed, and both the chambers are communicated with each other through an orifice passage.

  By the way, such an anti-vibration mount may require different spring characteristics in various directions in which vibration is input. For example, in an automobile, for the purpose of achieving both high driving stability and a high level of comfort, it is lower in the direction perpendicular to the axis of the mount, which is substantially the longitudinal direction of the vehicle, compared to the axial direction of the mount, which is substantially the vertical direction of the vehicle. Spring characteristics may be required.

  Therefore, conventionally, in order to cope with such a demand, for example, (a) the ratio of the axial dimension to the axial perpendicular direction dimension of the main rubber elastic body is increased or disclosed in Patent Documents 1 and 2. (B) It is proposed that the spring constant in the direction perpendicular to the axis of the anti-vibration mount is made lower than that in the axial direction by, for example, forming a recess or groove in the main rubber elastic body. ing.

  However, in the former method (a), there is a problem that the free surface area of the main rubber elastic body is increased, the effective piston area is reduced, and the vibration isolation effect based on the fluid flow action through the orifice passage is not sufficiently exhibited. there were. In the latter method (b), there is a problem that it is difficult to obtain a sufficient spring ratio between the mount axis direction and the mount axis perpendicular direction. There is a problem that the thickness of the rubber elastic body in the portion where the groove or the like is formed becomes small, and the spring rigidity in the axial direction also decreases. In addition, as shown in the anti-vibration mount according to Patent Document 1 of the latter (b), the main rubber elastic body interposed between the first mounting member and the second mounting member has a substantially full length. If a thin wall portion with a reduced wall thickness is formed, the pressure fluctuation in the pressure receiving chamber is absorbed by the deformation of the thin wall portion when vibration in the tuning frequency range of the orifice passage is input, and the pressure receiving chamber There has been a problem that relative pressure fluctuations cannot be efficiently generated between the equilibrium chambers. As a result, a sufficient amount of fluid flow through the orifice passage is difficult to be ensured, and there is a problem that it is difficult to effectively exhibit the vibration isolation characteristics inherent to the mount based on the fluid action of the fluid flowing through the orifice passage. It is.

JP 10-339348 A Japanese Utility Model Publication No. 3-2749

  Here, the present invention has been made in the background as described above, and the solution is to ensure basic performance so that pressure fluctuations in the pressure receiving chamber are sufficiently efficiently exhibited. However, the object of vibration isolation is stably supported by advantageously securing the spring stiffness in the axial direction, and the spring characteristic in the direction perpendicular to the axis is set soft, so that the target low in that direction is achieved. An object of the present invention is to provide a fluid-filled vibration-proof mount having a novel structure that can advantageously obtain an effect based on spring characteristics.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. 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 separated from each other on the side of one opening in the axial direction of the cylindrical second mounting member. The members are connected by a rubber elastic body to cover one axial opening of the second mounting member in a fluid-tight manner, and the other axial opening of the second mounting member is covered with a flexible membrane. Cover the fluid tightly, and further dispose a partition member between the main rubber elastic body and the flexible membrane and support it on the second mounting member, so that the wall portion is sandwiched between the both sides of the partition member. A pressure receiving chamber, part of which is made of the rubber elastic body, receives vibrations, and a part of the wall is made of the flexible film to form an equilibrium chamber in which volume change is easily allowed. A fluid in which an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, and an orifice passage is formed for communicating the two chambers. A first anti-vibration mount that is open to an inner surface facing the pressure-receiving chamber and an outer surface exposed to the outside at a position deviating from an elastic central axis of the main rubber elastic body; Two counterbore holes are provided so as to extend substantially in the axial direction, respectively, and one bottom part of the first and second counterbore holes is perpendicular to the axis in a depth configuration extending in the axial direction beyond the other bottom part. The fluid-filled vibration-proof mount has an elastic flange wall extending in a substantially axial direction between the first vertical hole and the second vertical hole facing each other in the direction perpendicular to the axial direction. is there.

  In the fluid-filled vibration isolating mount having the structure according to this aspect, the first counterbore and the second hoisthole are opposed to each other in the direction perpendicular to the axis of the mount, and the shaft Are opened on different sides in the direction, and each bottom of each of the counterbore holes extends substantially in the axial direction of the mount in a depth form exceeding the other bottom. That is, the first and second straight holes are formed in the main rubber elastic body so as to overlap each other in the direction perpendicular to the axis. Thereby, since it is a fluid-filled type, low spring characteristics in the direction perpendicular to the axis can be advantageously realized even in the vibration-proof mount in which the depth dimension of the straight hole in the main rubber elastic body is limited.

  Here, in this aspect, with the formation of the first counterbore and the second counterbore, an elastic ridge wall extending substantially in the axial direction is formed between the axially perpendicular opposed surfaces of both the counterbore holes, When axial vibration is input between the first mounting member and the second mounting member, axial compression and / or tensile deformation occurs in the elastic wall. On the other hand, when vibration in the direction perpendicular to the axis is input between the first and second mounting members, a pair of straight holes are provided that are opposed to each other in the direction perpendicular to the axis, particularly with the elastic flange wall in between. In the main rubber elastic body at the site, shear deformation is dominant. As a result, the spring constant in the direction perpendicular to the mount axis is set lower than the spring constant in the mount axis direction.

  Accordingly, in such a fluid-filled vibration-proof mount, when the spring ratio between the axial direction and the axis-perpendicular direction is increased, the mount shaft direction becomes the vibration-proof target member when disposed between the members of the vibration transmission system. One of the vibrations to be damped is the direction perpendicular to the mount axis in which the first and second holes are opposed to each other with the elastic saddle wall in between. By setting one in the input direction, the desired effect based on the spring characteristics in each direction can be advantageously obtained. Specifically, for example, when the mount is applied to an anti-vibration mount for automobiles, the mount axis direction is the vehicle vertical direction, and the direction perpendicular to the axis provided with the first and second straight holes and the elastic saddle wall Is set in the longitudinal direction of the vehicle, the support rigidity of the vibration isolation target member can be advantageously ensured based on the high spring characteristic in the vertical direction of the vehicle, and excellent ride comfort based on the low spring characteristic in the longitudinal direction of the vehicle Can be realized.

  In addition, in the vibration-proof mount of this aspect, the elastic flange wall extends in the substantially axial direction, so that the spring stiffness in the axial direction is advantageously ensured. Therefore, the elasticity of the main rubber elastic body at the time of axial vibration input With the deformation, an effective pressure fluctuation is induced in the pressure receiving chamber, and a relative pressure fluctuation is advantageously generated between the pressure receiving chamber and the equilibrium chamber. As a result, a sufficient amount of fluid flow through the orifice passage is secured on the basis of relative pressure fluctuations between the two chambers. An anti-vibration effect based on a fluid action such as a resonance action of the fluid to be caused to flow can be advantageously exhibited.

(Aspect 2 of the present invention)
The aspect 2 of the present invention is characterized in that, in the fluid-filled vibration isolating mount according to the aspect 1 of the present invention, each pair is provided on both sides of the main rubber elastic body in the direction perpendicular to the axis across the first mounting member. The first and second holes are provided so that the pair of elastic rib walls are opposed to each other in a direction perpendicular to the axis with the first mounting member interposed therebetween.

  In this aspect, the low spring characteristic is realized more advantageously by setting the direction perpendicular to the axis in which the pair of elastic flange walls are opposed to each other to the desired low spring characteristic. obtain. Further, in this aspect, in addition to increasing the spring ratio in the direction perpendicular to the axis in which the mount axial direction and the pair of elastic collar walls are opposed to each other, the axis perpendicular direction in which the pair of elastic collar walls are opposed to each other The spring ratio with respect to the direction orthogonal to the direction perpendicular to the axis where no elastic ribs are provided can also be set large.

(Aspect 3 of the present invention)
The aspect 3 of the present invention is characterized in that in the fluid-filled vibration isolating mount according to the aspect 1 or 2 of the present invention, the first mounting member is integrally provided with an action protrusion that extends in a direction perpendicular to the axis. At the same time, the first straight hole or the second straight hole is provided below the working protrusion in the axial direction.

  In such a mode, by providing the action protrusion on the axially upper side of the main rubber elastic body having the straight hole, the spring rigidity in the axial direction of the portion having the straight hole is advantageously ensured. . Therefore, at the time of axial vibration input, the piston action against the pressure receiving chamber is effectively exerted by the main rubber elastic body provided with the straight hole provided below the action protrusion. Since a large pressure fluctuation is generated in the pressure receiving chamber with a large piston efficiency, the vibration isolation effect based on the fluid action such as the resonance action of the fluid through the orifice passage due to the pressure difference between the pressure receiving chamber and the equilibrium chamber is more advantageous. It can be demonstrated.

  Note that the piston action on the pressure receiving chamber in the main rubber elastic body means an action that exerts pressure fluctuations on the pressure receiving chamber based on elastic deformation of the main rubber elastic body at the time of axial vibration input. When the first mounting member and the second mounting member are displaced by a unit amount in the axial direction, a large pressure fluctuation is generated.

(Aspect 4 of the present invention)
A feature of the fourth aspect of the present invention is that in the fluid-filled vibration isolating mount according to any one of the first to third aspects of the present invention, the natural frequency of the elastic saddle wall can be caused to flow in the orifice passage. This means that tuning is performed in the frequency range of vibration to be damped in a frequency range higher than the resonance frequency of the fluid.

  In such a mode, when vibration in a frequency range higher than the tuning frequency of the orifice passage is input in the axial direction, the orifice passage is substantially closed, but the higher the pressure in the pressure receiving chamber, the higher the pressure. The dynamic spring is avoided by the deformation of the elastic wall. Therefore, in this aspect, the natural frequency of the elastic saddle wall is tuned to a frequency range higher than the tuning frequency of the orifice passage, which is combined with the resonance action of the elastic saddle wall at the vibration input in the frequency range. Thus, since the elastic deformation of the elastic collar wall is positively generated, an effective pressure fluctuation absorbing function is exhibited in the pressure receiving chamber by the volume change of the pressure receiving chamber based on the elastic deformation of the elastic collar wall. Accordingly, high dynamic springs accompanying an increase in pressure in the pressure receiving chamber due to substantial obstruction of the orifice passage can be avoided, and good vibration isolation performance can be exhibited.

(Aspect 5 of the present invention)
A feature of the fifth aspect of the present invention is that in the fluid-filled vibration isolating mount according to any one of the first to fourth aspects of the present invention, a movable rubber plate is provided inside the partition member by a predetermined amount in the thickness direction. The displacement or deformation is arranged so that the internal pressures of the pressure receiving chamber and the equilibrium chamber are exerted on one surface of the movable rubber plate.

  In this embodiment, even when high-frequency vibration is input so that the orifice passage is substantially closed, the pressure fluctuation in the pressure receiving chamber is reduced or absorbed based on the displacement or deformation of the movable rubber plate. In addition, it is possible to obtain a good vibration-proofing effect by preventing a significant increase in the dynamic spring.

(Aspects of the present invention relating to automobile engine mounts)
A feature of the aspect of the present invention relating to an automobile engine mount is that one of the first mounting member and the second mounting member is attached using the fluid-filled vibration isolating mount according to the fifth aspect of the present invention. By attaching to the power unit of the automobile and the other to the body of the automobile, the power unit is supported to be vibration-proof with respect to the body, while the resonance frequency of the fluid that is allowed to flow through the orifice passage is reduced by a shake or the like. Tuning to the frequency frequency range, tuning the natural frequency of the movable rubber plate to a medium frequency frequency range such as idling vibration, and further adjusting the natural frequency of the elastic wall to the high frequency frequency range such as running noise It is in the car engine mount tuned to.

  In an automotive engine mount having a structure according to this embodiment, any of low frequency large amplitude vibrations such as shakes, medium frequency medium amplitude vibrations such as idling vibrations, and high frequency small amplitude vibrations such as traveling humming noises. However, an engine mount that can exhibit an effective anti-vibration effect can be advantageously realized.

  As is clear from the above description, in the fluid-filled vibration isolating mount structured according to the present invention, the first and second staking holes extending in the substantially axial direction are overlapped with each other in the direction perpendicular to the axis. In addition, the elastic flange wall extending in the substantially axial direction is formed between the two straight holes, so that the spring ratio between the direction perpendicular to the mount axis and the direction of the mount axis is effectively set large. Therefore, when applied to, for example, an anti-vibration mount for automobiles, the orifice passage is accompanied by the fact that the pressure fluctuation in the pressure receiving chamber is sufficiently efficiently exhibited by ensuring a large spring stiffness in the axial direction. Of course, the vibration isolation performance based on the fluid flow action through the vehicle can be advantageously exhibited, and further, the high spring stiffness in the axial direction can advantageously ensure the support spring stiffness in the vehicle vertical direction, and the direction perpendicular to the axis The ride comfort can be advantageously improved based on the low spring characteristic in the vehicle longitudinal direction due to the low spring characteristic.

  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. Further, the engine mount 10 is configured such that the first mounting bracket 12 is mounted on the power unit side while the second mounting bracket 14 is mounted on the body so that the power unit is supported in a vibration-proof manner with respect to the body. . In such a mounting state, the first mounting bracket 12 and the second mounting bracket 14 are attached to the mount 10 as the main rubber elastic body 16 is elastically deformed by the input of the power unit load. The main vibration to be vibrated is input in the vertical direction in FIG. 1 between the first mounting bracket 12 and the second mounting bracket 14 while being relatively displaced by a predetermined amount in the vertical direction. The Rukoto.

  More specifically, the first mounting member 12 has a substantially cylindrical or hemispherical shape, and a mounting bolt 18 that protrudes upward (upward in FIG. 1) is fixed to the central portion thereof. Yes. In addition, an annular protrusion 20 is integrally formed at an axially intermediate portion of the first mounting member 12 as an action protrusion that expands in a substantially annular shape outward in the direction perpendicular to the axis.

  On the other hand, the second mounting bracket 14 has a large-diameter, generally cylindrical shape, and is spaced apart downward (downward in FIG. 1) on the same center axis as the first mounting bracket 12. Further, the upper end portion in the axial direction of the second mounting bracket 14 is bent inward in the radial direction, and has a tapered cylindrical portion 22 having a reverse tapered shape in which the diameter dimension gradually increases in a conical shape from the bottom to the top. It is said that. Further, a caulking portion 24 having a large diameter is integrally formed at the lower end portion in the axial direction of the second mounting member 14 through a step portion.

  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 the first mounting bracket 12 is superimposed on the end surface on the small diameter side so that the lower end portion of the first mounting bracket 12 and the annular protrusion 20 are formed. It is vulcanized and bonded with almost the entire surface except the top surface inserted. Further, the inner peripheral surface of the tapered cylindrical portion 22 of the second mounting bracket 14 is superimposed on the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16 and vulcanized and bonded. 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. As is clear from this, one of the openings in the axial direction (upper in FIG. 1) of the second mounting bracket 14 is covered with a main rubber elastic body 16 in a fluid-tight manner.

  A large-diameter circular recess 26 that opens downward is formed on the large-diameter side end face of the main rubber elastic body 16. Thereby, the tensile stress due to the input of the support load of the power unit is reduced or avoided. Further, particularly in the present embodiment, as shown in FIG. 1, the bottom of the circular recess 26 is a substantially flat circle in a state where the main rubber elastic body 16 is elastically deformed with the input of the support load. It is made into a shape. In addition, the outer peripheral edge of the bottom of the circular recess 26 is curved so that the diameter dimension gradually increases as it goes downward from the bottom, and is in smooth contact with the substantially cylindrical peripheral wall of the circular recess 26. Yes. Further, a thin seal rubber layer 28 integrally formed with the main rubber elastic body 16 is attached to the inner peripheral surface of the second mounting bracket 14 over substantially the whole.

  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 30 and a diaphragm 32 as a flexible film are assembled. The partition fitting 30 has a substantially cylindrical shape. The diaphragm 32 is formed of a thin rubber elastic film that can be easily deformed, and a substantially annular fitting 34 is vulcanized and bonded to the outer peripheral edge. The partition fitting 30 and the diaphragm 32 are fitted into the second mounting bracket 14, and the upper end portion of the partition fitting 30 is overlapped with the stepped portion in contact with the tapered cylindrical portion 22, and the diaphragm 32 is integrated with the diaphragm 32. The sulfur fitting fitting 34 is superimposed on the stepped portion in contact with the caulking portion 24. Further, the caulking portion 24 is caulked and fixed to the outer peripheral edge portion of the fitting 34, and the cylindrical wall portion of the second mounting bracket 14 is subjected to drawing processing. The rubber elastic body 16 is fixed to the integrally vulcanized molded product. As a result, the other opening in the axial direction of the second mounting bracket 14 in the integrally vulcanized molded product is fluid-tightly closed by the diaphragm 32.

  Furthermore, a fluid chamber in which an incompressible fluid is sealed is formed between the main rubber elastic body 16 and the diaphragm 32 in the second mounting bracket 14 sealed with respect to the external space. For example, water, alkylene glycol, polyalkylene glycol, silicone oil or the like is employed as such a sealed fluid. 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 30 and the diaphragm 32 to the integrally vulcanized molded product of the main rubber elastic body 16 including the first and second mounting brackets 12 and 14. It is realized by performing in the inside.

  In addition, the fluid chamber is divided into two parts in the vertical direction by assembling the partition fitting 30 so as to expand in the direction perpendicular to the axis at the axially intermediate portion. 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 fitting 30, and the first mounting bracket 12 and the second mounting bracket 12 are arranged. A pressure receiving chamber 36 is formed in which pressure fluctuations are generated when vibration is input between the mounting brackets 14. On the other hand, on the other side in the axial direction with the partition metal fitting 30 interposed therebetween, a part of the wall portion is constituted by a diaphragm 32, and an equilibrium chamber 38 is formed in which volume change is allowed based on elastic deformation of the diaphragm 32. ing.

  Further, the partition fitting 30 is formed with a circumferential groove 40 that is open to the outer peripheral surface and continuously extends in a substantially spiral shape in the circumferential direction, and the circumferential groove 40 is fluid-tight with the second mounting fitting 14. Covered. In addition, one end of the circumferential groove 40 is connected to the pressure receiving chamber 36 through a communication hole 42 formed in the upper wall portion or the like of the partition fitting 30 and the other end of the circumferential groove 40 is connected to the partition fitting. 30 is connected to the equilibration chamber 38 through a communication hole 44 formed in the lower wall portion and the like. As a result, the circumferential groove 40 of the partition member 30 and the second mounting member 14 cooperate to form an orifice passage 46, and the pressure receiving chamber 36 and the equilibrium chamber 38 are communicated with each other through the orifice passage 46. Therefore, a relative pressure fluctuation is caused between the pressure receiving chamber 36 in which the pressure fluctuation is caused and the equilibrium chamber 38 in which the volume change is allowed based on the deformation of the diaphragm 32. 38, fluid flow through the orifice passage 46 is produced. As a result, the fluid flow through the orifice passage 46 is generated between the pressure receiving chamber 36 and the equilibrium chamber 38, and the vibration isolation effect based on the resonance action of the fluid that flows through the orifice passage 46 has the axial direction to be vibration-proof. It is designed to be effective against vibrations. The resonance frequency of the fluid flowing through the orifice passage 46 is tuned so as to exhibit an effective vibration-proofing effect against low-frequency large-amplitude vibration of about 10 Hz such as a shake based on the resonance action of the fluid. ing. Such tuning of the resonance frequency is realized, for example, by changing the setting of the cross-sectional area and length of the orifice passage 46.

  Furthermore, a circular central recess 48 that opens upward is formed in the central portion of the partition member 30, and the movable rubber plate 50 is accommodated in the central recess 48. The movable rubber plate 50 is disposed so as to be displaceable in an axial direction or the like between a bottom wall of the central recess 48 and a substantially annular support lid fitting 52 fitted and fixed in the opening of the central recess 48. In such an assembled state, the upper surface of the movable rubber plate 50 is exposed to the pressure receiving chamber 36 through the through hole 54 penetrating the support lid fitting 52, while the lower surface of the movable rubber plate 50 is centered. It is exposed to the equilibrium chamber 38 through a through hole 56 penetrating the bottom wall of the recess 48. Therefore, the internal pressure of the pressure receiving chamber 36 and the equilibrium chamber 38 is exerted on the movable rubber plate 50 on the upper and lower surfaces. Based on the pressure difference between the pressure receiving chamber 36 and the equilibrium chamber 38 at the time of vibration input, elastic deformation or axial direction is achieved. Displacement is produced. Then, the fluid flow through the through holes 54 and 56 of the support lid fitting 52 and the partition fitting 30 is generated based on the elastic deformation of the movable rubber plate 50 or the displacement in the axial direction. Based on the fluid pressure absorbing action related to the chamber 36, a low dynamic spring effect with respect to the input vibration is exhibited.

  It should be noted that the natural frequency of the movable rubber plate 50 is, for example, idling vibration based on the elastic deformation of the movable rubber plate 50 or the fluid action such as the resonance action of fluid through the through holes 54 and 56 accompanying the axial displacement. It is tuned so as to exhibit an effective anti-vibration effect with respect to medium-frequency medium amplitude vibration of about 100 Hz. For tuning the natural frequency of the movable rubber plate 50, for example, the spring characteristics are changed in accordance with the setting change of the thickness and shape of the rubber plate 50, and the cross-sectional areas and lengths of the through holes 54 and 56 are changed. This is realized by changing the setting. The movable rubber plate 50 has its elastic deformation limited by its own elasticity and contact with the partition fitting 30 and the support lid fitting 52 at the center of the movable rubber plate 50. At the time of vibration input with low frequency and large amplitude, the amount of fluid flow associated with elastic deformation of the movable rubber plate 50 is limited, and the amount of fluid flow through the orifice passage 46 is ensured.

  Further, in the main rubber elastic body 16 continuously extending in the circumferential direction between the opposing surfaces of the first mounting bracket 12 and the second mounting bracket 14, one radial direction (in FIG. 2) sandwiching the first mounting bracket 12. , Left and right) are provided in such a manner that a pair of inner straight portions 58 as the first straight holes are opposed to each other. The inner curly portion 58 has a substantially arc shape extending in the circumferential direction with a predetermined width between the first mounting bracket 12 and the second mounting bracket 14 in a plan view in the axial direction, and in the mount axial direction (FIG. 1). (Middle, top and bottom). The bottom portion 60 of the inner curly portion 58 is formed in the vicinity of the small-diameter end of the main rubber elastic body 16 and is opposed to the annular protrusion 20 of the first mounting member 12 in the axial direction. It extends in the circumferential direction with a substantially hemispherical cross section. Further, the opening of the inner straight portion 58 is opened in the pressure receiving chamber 36 through the circular recess 26 of the main rubber elastic body 16. That is, the inner straight portion 58 of the present embodiment is an elastic central axis (in this embodiment, the first and second mounting brackets 12) extending in the main load input direction which is the vertical direction in FIG. 1 in the main rubber elastic body 16. , 14, the central rubber elastic body 16 interposed between the opposing surfaces of the first and second mounting brackets 12, 14 below the annular protrusion 20 at a position deviated from the central axis of the mount 10. The radially inner portion of each of them extends substantially straight in the axial direction with a substantially constant arc cross section or arcuate cross section.

  Further, an outer straight portion 62 as a second straight hole is formed on the outer side in the radial direction of each inner straight portion 58. The outer curving portion 62 has a circumferential length longer than the inner curling portion 58 in a plan view in the axial direction, and is a substantially arc extending in the circumferential direction with a predetermined width between the first mounting bracket 12 and the second mounting bracket 14. It has a shape and extends substantially parallel to the mount axis direction (up and down in FIG. 1). Further, the bottom 64 of the outer straight portion 62 extending in the circumferential direction with a substantially hemispherical cross section is formed in the vicinity of the large-diameter side end of the main rubber elastic body 16 in the same manner as the inner straight portion 58, and the large-diameter side end portion outer periphery. The second mounting bracket 14 vulcanized and bonded to the surface is positioned above the opening of one axial direction (upper in FIG. 1), and the opening of the outer straight portion 62 is elastic on the main body. The body 16 is opened on the outer peripheral surface having a substantially tapered shape. In short, the outer straight portion 62 is located between the opposing surfaces of the first and second mounting brackets 12 and 14 at a position radially outward from the inner straight portion 58 at a position deviated from the elastic central axis of the main rubber elastic body 16. The radially outer portion of the interposed main rubber elastic body 16 extends substantially straight in the axial direction with a substantially constant arc cross section or arcuate cross section. As a result, the inner straight portion 58 and the outer straight portion 62 are opposed to each other in the direction perpendicular to the axis between the first mounting bracket 12 and the second mounting bracket 14, and the inner curling portion 58 and Each one of the bottom portions 60 (64) of the outer straight portion 62 extends substantially straight in the axial direction of the mount with a depth that exceeds the other bottom portion 64 (60).

  Further, a heel wall portion 66 as an elastic heel wall is provided between the axially perpendicular facing surfaces of the inner straight portion 58 and the outer straight portion 62. The flange wall portion 66 has a circumferential length longer than the inner straight portion 58 and shorter than the outer straight portion 62 in a plan view in the axial direction, and has a predetermined distance between the first mounting bracket 12 and the second mounting bracket 14. While having a substantially arc shape extending in the circumferential direction with a width, a radially intermediate portion of the main rubber elastic body 16 extends substantially straight with a substantially constant arc cross section or arcuate cross section substantially parallel to the mount axis direction. In other words, in the present embodiment, the pair of flange wall portions 66 formed between the surfaces facing the axially perpendicular direction of the inner straight portion 58 and the outer straight portion 62 is the first at a position deviated from the elastic central axis of the main rubber elastic body 16. In one radial direction (left and right in FIG. 2) sandwiching one mounting bracket 12, they are spaced apart and opposed to each other. As a result, the spring constant in the direction perpendicular to the axis (left and right in FIG. 2) in which the pair of ribs 66, 66 are opposed to each other is not provided with the rib 66 that is orthogonal to the direction perpendicular to the axis. It is made lower than the spring constant in the direction perpendicular to the axis (up and down in FIG. 2) in which the actual rubber part is positioned opposite.

  Furthermore, the collar wall portion 66 is configured as a part of the wall portion of the pressure receiving chamber 36 via the inner straight portion 58. Therefore, the natural frequency of the wall 66 is based on elastic deformation of the wall 66 in a higher frequency range than the resonance frequency of the fluid flowing through the orifice passage 46 and the natural frequency of the movable rubber plate 50. For example, it is tuned so as to exhibit an effective anti-vibration effect against high-frequency small-amplitude vibrations of about 300 Hz such as traveling noise.

  Further, the expansion spring rigidity of the flange wall portion 66 is made larger than the expansion spring rigidity of the diaphragm 32 constituting a part of the wall portion of the equilibrium chamber 38. Here, the expansion spring rigidity represents the ease of bulging deformation of the wall portion, and the volume of the pressure receiving chamber 36, the equilibrium chamber 38, etc. is changed by a unit amount based on the elastic deformation of the wall portion. It can be grasped as a value corresponding to the amount of change in internal pressure required for the above.

  The shape, size, structure, and the like of the ridge wall portion 66 are not limited in any way, but in this embodiment, for example, the thickness dimension of the heel wall portion 66: T and the axial dimension of the ridge wall portion 66: L ratio value: L / T is preferably set to L / T ≧ 1.5, more preferably L / T ≧ 2.

  A bracket fitting 68 is attached to the engine mount 10 having such a structure. The bracket fitting 68 includes a support cylinder portion 70 having a large-diameter, generally cylindrical shape, and three fixing legs 72, 72, 72 fixed to the outer peripheral surface of the support cylinder portion 70. The second mounting bracket 12 of the mount 10 is press-fitted and fixed to the support cylinder 70, and each fixing leg 72 is not shown through a fixing hole 74 penetrating the leg. It is bolted to the car body. Further, the first mounting bracket 12 is attached to an automobile power unit (not shown) via a mounting bolt 18. As a result, the engine mount 10 is attached to the power unit via the mounting bolts 18 and is also attached to the vehicle body via the bracket fitting 68, so that the power unit is supported by the body against vibration. It has become.

  In particular, in the present embodiment, the axial direction of the mount 10 (up and down in FIG. 1) is set in the vehicle vertical direction, and each pair of the inner straight portion 58, the outer straight portion 62, and the saddle wall portion 66 is the first attachment. A direction perpendicular to the axis (left and right in FIG. 2) positioned opposite to each other with the metal fitting 12 interposed therebetween is set in the vehicle longitudinal direction, and a pair of inner and outer straight portions 58 and 62 and a collar wall 66 are positioned opposite to each other. The mount 10 is mounted on the automobile in a form in which the direction perpendicular to the perpendicular direction (up and down in FIG. 2) is set in the vehicle lateral direction.

  In the engine mount 10 for an automobile having the above-described structure, when a low-frequency large-amplitude vibration such as a shake is input between the first mounting bracket 12 and the second mounting bracket 14 in the axial direction, the main body The piston action of the rubber elastic body 16 on the pressure receiving chamber 36 causes a large pressure fluctuation in the pressure receiving chamber 36, and the relative pressure fluctuation is efficiently exerted between the pressure receiving chamber 36 and the equilibrium chamber 38. A sufficient amount of fluid flow through the orifice passage 46 can be ensured. Therefore, an anti-vibration effect (vibration damping effect) can be effectively exhibited based on a fluid action such as a resonance action of a fluid that is caused to flow through the orifice passage 46 between the pressure receiving chamber 36 and the equilibrium chamber 38.

  Further, when medium-frequency medium amplitude vibration such as idling vibration in a frequency range higher than the tuning frequency of the orifice passage 46 is input between the first mounting bracket 12 and the second mounting bracket 14, the orifice passage 46 is substantially closed, but the fluid resonates through the through holes 54 and 56 due to elastic deformation or axial displacement of the movable rubber plate 50 disposed between the pressure receiving chamber 36 and the equilibrium chamber 38. An anti-vibration effect (vibration insulation effect) can be effectively exhibited based on a fluid action such as an action.

  Further, when high-frequency small amplitude vibration such as traveling boom noise that is in a frequency range higher than the tuning frequency of the orifice passage 46 or the movable rubber plate 50 is input between the first mounting bracket 12 and the second mounting bracket 14. In addition, the orifice passage 46 is substantially closed, and the through holes 54 and 56 are also substantially closed due to the fact that elastic deformation or the like of the movable rubber plate 50 is not effectively generated. However, in the pressure receiving chamber 36, a part of the wall portion includes the heel wall portion 66, so that pressure fluctuation is avoided by deformation of the heel wall portion 66. In particular, in the present embodiment, the natural frequency of the heel wall portion 66 is tuned to a higher frequency range than the tuning frequency of the orifice passage 46 and the movable rubber plate 50, so that the heel wall portion 66 in the vibration input of the frequency range. Since the elastic deformation of the flange wall portion 66 is positively generated in combination with the resonance action, effective pressure fluctuation in the pressure receiving chamber 36 due to the volume change of the pressure receiving chamber 36 based on the elastic deformation of the flange wall portion 66. Absorption function is demonstrated. Therefore, the high dynamic spring accompanying the pressure increase in the pressure receiving chamber 36 due to the substantial closure of the orifice passage 46 and the through holes 54 and 56 is avoided, and the vibration isolation effect (vibration insulation effect) is effectively exhibited. To get.

  In particular, since the orifice passage 46, the movable rubber plate 50, and the flange wall portion 66 tuned to different frequency ranges can function effectively, the orifice passage in a high frequency range exceeding the tuning frequency of the orifice passage 46. When the tuning frequency of the movable rubber plate 50 is set in a frequency range where the anti-resonance action is a problem, the movable rubber plate 50 is made to have a significantly high dynamic spring due to the anti-resonance action due to the fact that 46 is substantially blocked. It can suppress based on the elastic deformation accompanying the resonance effect | action of the board 50. FIG. Similarly, in the high frequency range exceeding the tuning frequency of the movable rubber plate 50, the through holes 54 and 56 located on both sides in the axial direction of the movable rubber plate 50 are substantially blocked. Remarkably high dynamic spring due to the resonance action is suppressed based on elastic deformation accompanying the resonance action of the wall part 66 by setting the tuning frequency of the wall part 66 in the frequency region where the anti-resonance action is a problem. I can do it. Therefore, it is possible to obtain an excellent anti-vibration effect against a plurality of vibrations in a wide frequency range.

  Therefore, in the present embodiment, the pair of inner curling portions 58 and the outer curling portions 62 are disposed so as to face each other in one direction perpendicular to the axis across the first mounting bracket 12 in the main rubber elastic body 16. In addition, a pair of ridge wall portions 66, 66 are provided by providing a ridge wall portion 66 extending substantially in the axial direction between the opposing surfaces in the direction perpendicular to the axis of the inner and outer straight portions 58, 62. A low spring characteristic in the direction perpendicular to the axis of the part can be advantageously realized while sufficiently ensuring the rigidity of the part in the axial direction. That is, the spring ratio in the direction perpendicular to the axis and in the axial direction is effectively increased in the portion where each pair of the inner and outer straight portions 58 and 62 and the wall portion 66 is provided.

  Accordingly, in the automobile engine mount 10 of the present embodiment, the mount axis direction extending substantially parallel to the inner and outer curb portions 58 and 62 and the saddle wall portion 66 is set to the vehicle vertical direction to which a power unit load or the like is input. Mounted between the power unit and the vehicle body in such a manner that the mount axis perpendicular direction in which each pair of the inner curly portion 58, the outer curly portion 62, and the collar wall portion 66 are opposed to each other is set in the vehicle front-rear direction. As a result, it is possible to achieve a high degree of compatibility between the securing of the support rigidity of the power unit and the riding comfort based on the low spring characteristic in the longitudinal direction of the vehicle.

  In addition, in the present embodiment, the two straightened portions 58, 62 and the flanges in the direction perpendicular to the axis perpendicular to the direction in which the pair of inner and outer straightened portions 58, 62 and the flange wall portion 66 of the main rubber elastic body 16 are opposed to each other. Since the wall portion 66 is not provided, and the direction perpendicular to the axis of the portion where the wall portion 66 or the like is not provided is the left-right direction of the vehicle, it is excellent based on the high spring characteristics in the left-right direction of the vehicle. Steering stability is obtained.

  Further, in the present embodiment, since the flange wall portion 66 extends straight in the substantially axial direction, it is substantially compressed and deformed in the axial direction, and therefore, between the first mounting bracket 12 and the second mounting bracket 14. When an axial vibration is input to the pressure receiving chamber 36, an effective piston action accompanying the compression deformation of the flange wall portion 66 is exerted on the pressure receiving chamber 36. As a result, as the pressure fluctuation is more effectively induced in the pressure receiving chamber 36, the vibration isolation effect based on the fluid flow action through the orifice passage 46 between the pressure receiving chamber 36 and the equilibrium chamber 38 is more advantageously exhibited. It can be done.

  Furthermore, in the present embodiment, the expansion spring rigidity of the flange wall portion 66 is made larger than the expansion spring rigidity of the diaphragm 32, so that an effective pressure fluctuation is induced in the pressure receiving chamber 36. As a result, the orifice As the fluid flow amount in the passage 46 is ensured, the vibration isolation effect can be exhibited more advantageously.

  Incidentally, FIG. 3 shows the result of measuring the frequency characteristics of the vibration proof performance of the automobile engine mount 10 having the structure according to the above-described embodiment. This measurement result is obtained by detecting vibration on the input side and output (transmission) side with a sensor when an axial excitation force is applied between the first mounting bracket 12 and the second mounting bracket 14. The vibration transfer characteristics were measured when the excitation frequency was gradually changed and the frequency sweep was applied. Further, the solid line in FIG. 3 is a graph showing the result of measuring the vibration transfer characteristics of the engine mount 10 having the structure according to the present embodiment, and the broken line in FIG. 3 indicates the engine mount 10 of the present embodiment. 6 is a graph showing the results of measuring the vibration transfer characteristics according to the engine mount as a comparative example in which the inner straight portion 58, the outer straight portion 62, and the collar wall portion 66 are not provided.

  From the results shown in FIG. 3, for example, when an intermediate frequency vibration of about 100 Hz such as idling vibration is input, the automobile engine mount 10 of the present embodiment and the engine mount of the comparative example both cause elastic deformation of the movable rubber plate 50. It is recognized that the low dynamic spring effect can be effectively exhibited based on the flow action such as the resonance action of the fluid through the associated through holes 54 and 56.

  In this regard, for example, when high frequency vibration of about 300 Hz such as traveling noise is input, in the engine mount of the comparative example, there is a significant increase in dynamic spring due to the anti-resonant action of the orifice passage 46 and the through holes 54 and 56. In contrast, in the engine mount 10 according to the present embodiment, it is recognized that the low dynamic spring action is exhibited in the vibration frequency range. Note that the arrow pointing downward in FIG. 3 visually indicates that the dynamic spring constant of the embodiment is advantageously reduced as compared to the comparative example when inputting vibrations in a high frequency range such as a traveling noise. It is a representation.

  Therefore, also from the above-mentioned results, the low dynamic spring action in the high-frequency frequency range such as traveling noise is exerted based on the elastic deformation accompanying the resonance action of the flange wall portion 66, thereby the orifice passage 46. It is presumed that the remarkably high dynamic spring due to the anti-resonance of the through holes 54 and 56 is advantageously suppressed.

  The embodiment of the present invention has been described in detail above, but this is merely an example, and the present invention is not limited to a specific description in the embodiment, and is based on the knowledge of those skilled in the art. The present invention can be implemented with various changes, modifications, improvements, and the like, and any such embodiments are included in the scope of the present invention without departing from the spirit of the present invention. Needless to say.

  For example, in the above-described embodiment, the inner straight portion 58, the outer straight portion 62, and the flange wall portion 66 extend straight with a substantially constant cross-sectional shape in the axial direction. As long as the low spring characteristic is within the range, the cross-sectional shape may be inclined with respect to the axial direction or changed in the axial direction.

  In the above-described embodiment, the inner straight portion 58 is opened on the inner surface of the main rubber elastic body 16 facing the pressure receiving chamber 36, and the outer straight portion 62 is opened on the outer surface of the main rubber elastic body 16 exposed to the outside. However, it is of course possible that the inner straight portion 58 is opened on the outer surface of the main rubber elastic body 16 and the outer straight portion 62 is opened on the inner surface of the main rubber elastic body 16.

  Furthermore, you may provide only one of the inner side straight part 58 or the outer side straight part 62 in some main rubber elastic bodies 16 which concern on the said embodiment.

  Furthermore, in the above-described embodiment, each pair of the inner straight portion 58, the outer straight portion 62, and the collar wall portion 66 is opposed to each other in one radial direction of the main rubber elastic body 16 with the first mounting bracket 12 interposed therebetween. In other words, although it was partially provided in the circumferential direction of the main rubber elastic body 16, the inner and outer straight portions 58 and 62 and the flange wall 66 are arranged in the circumferential direction of the main rubber elastic body 16. It is also possible to provide it so as to extend continuously over the entire circumference.

  In addition, an air chamber is formed between the lid member and the heel wall portion 66 by covering the entire outer straight portion 62 with a predetermined lid member, and by applying air pressure to the air chamber from the outside, the spring characteristics of the heel wall portion It is also possible to adjust and set the anti-vibration characteristics and spring ratio.

  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.

It is explanatory drawing which shows the engine mount for motor vehicles as one Embodiment of this invention, Comprising: It is a figure equivalent to the II cross section of FIG. FIG. 2 is an explanatory plan view showing the automobile engine mount in FIG. 1. It is a graph which shows the result of having measured the vibration proof characteristic in the engine mount for motor vehicles in FIG.

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 30 Partition metal fitting 32 Diaphragm 36 Pressure receiving chamber 38 Equilibrium chamber 46 Orifice passage 58 Inner straight part 60 Bottom part 62 Outer straight part 64 Bottom part 66 Wall

Claims (6)

The first mounting member is spaced apart on the one axial side opening side of the cylindrical second mounting member, and the first mounting member and the second mounting member are connected by the main rubber elastic body. The two opening members in the axial direction are covered with a fluid-tight cover, and the other opening portion in the axial direction of the second mounting member is covered with a flexible film in a fluid-tight manner. A partition member is disposed between the flexible membrane and supported by the second mounting member, so that part of the wall portion is formed of the main rubber elastic body on both sides of the partition member. A pressure receiving chamber into which vibration is input and an equilibrium chamber in which a part of the wall portion is made of the flexible film and the volume change is easily allowed are formed, and the pressure receiving chamber and the equilibrium chamber are incompressible. A fluid-filled vibration isolating mount that encloses a fluid and forms an orifice passage that communicates the two chambers.
At a position deviating from the elastic central axis of the main rubber elastic body, a first straight hole that opens to the inner surface facing the pressure receiving chamber and a second straight hole that opens to the outer surface exposed to the outside are substantially shafts, respectively. The bottom of one of the first and second counterbore holes is spaced apart in the direction perpendicular to the axis in a depth configuration extending in the axial direction beyond the other bottom. Thus, a fluid-filled vibration-proof mount is characterized in that an elastic saddle wall extending substantially in the axial direction is formed between the first and second counterbore surfaces facing each other in the direction perpendicular to the axis.   A pair of the first and second straight holes are provided on both sides of the main rubber elastic body with respect to the direction perpendicular to the axis across the first attachment member, and the pair of elastic rib walls The fluid-filled vibration-proof mount according to claim 1, wherein the fluid-filled vibration-proof mount is opposed to each other in a direction perpendicular to the axis with the mounting member interposed therebetween.   The first mounting member is integrally provided with an action protrusion that extends in a direction perpendicular to the axis, and the first and second straight holes are provided below the action protrusion in the axial direction. Or the fluid-filled vibration-proof mount according to 2.   The fluid according to any one of claims 1 to 3, wherein the natural frequency of the elastic saddle wall is tuned to a frequency range of vibration to be damped in a frequency range higher than a resonance frequency of a fluid flowing through the orifice passage. Enclosed anti-vibration mount.   A movable rubber plate is disposed in the partition member so as to be displaced or deformable by a predetermined amount in the thickness direction so that the internal pressures of the pressure receiving chamber and the equilibrium chamber are exerted on each surface of the movable rubber plate. The fluid-filled vibration-proof mount according to any one of claims 1 to 4. Using the fluid-filled vibration-proof mount according to claim 5, one of the first mounting member and the second mounting member is attached to an automobile power unit, and the other is attached to the automobile body, While making the power unit vibration-proof and support the body, the resonance frequency of the fluid flowing through the orifice passage is tuned to a low frequency frequency region such as a shake, and the natural frequency of the movable rubber plate is adjusted. An automobile engine mount characterized by being tuned to a medium frequency frequency range such as idling vibration, and further tuned to a high frequency frequency range such as running noise from the natural frequency of the elastic wall.

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