JP2013174322A - Fluid sealing type vibration isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid sealing type vibration isolation device further improved in vibration isolation performance based on the resonance action or the like of a sealing fluid while suppressing the complication of structure and a cost increase.SOLUTION: In a fluid sealing type vibration isolation device 10, a fluid passage 60 is formed between a pressure receiving chamber 50 and a balance chamber 52 in parallel with a low-frequency orifice passage 58, there are arranged elastic valve bodies 82, 86 which are elastically held in a position separated from an opening to the pressure receiving chamber 50 in the fluid passage 60 and close the opening by being pressed against the opening by the actin of fluid flowing in the opening, on the other hand, a middle-frequency orifice passage 94 is formed at an opening side to the balance chamber 52 in the fluid passage 60, a leak hole 92 for opening the fluid passage 60 to the balance chamber 52 is formed in parallel with the middle-frequency orifice passage 94, and furthermore, an opening/closing valve 42 for switching the leak hole 92 to a communicating state and a blocked state and an actuator 96 are arranged.

Description

  The present invention relates to a fluid-filled vibration isolator capable of obtaining a vibration-proof effect by utilizing the flow action of an incompressible fluid sealed therein, and in particular, a fluid-filled-type that can be used as an engine mount for an automobile. The present invention relates to a vibration isolator.

  2. Description of the Related Art Conventionally, a fluid-filled vibration isolator is known as a kind of a vibration isolating connection body or a vibration isolating support body interposed between members constituting a vibration transmission system such as a power unit of an automobile and a body. In such a fluid-filled vibration isolator, a vibration isolator in which a first attachment member attached to one member constituting a vibration transmission system and a second attachment member attached to the other member are connected by a main rubber elastic body. Is provided with a pressure receiving chamber and an equilibrium chamber in which an incompressible fluid is sealed. In the pressure receiving chamber, a part of the wall is made of a rubber elastic body, while in the equilibrium chamber, a part of the wall is made of a flexible film. Relative pressure fluctuations are induced during this period. The pressure fluctuation is used to generate a fluid flow through an orifice passage communicating with the pressure receiving chamber and the equilibrium chamber, thereby obtaining a vibration isolation effect based on the resonance action of the fluid.

  By the way, in an anti-vibration device such as an automobile engine mount, an anti-vibration effect is generally required for a plurality of types of vibrations having different frequencies and amplitudes. For example, in an engine mount for automobiles, high-level anti-vibration measures against idling vibration in the middle frequency range that is input when the vehicle is stopped, and low-frequency vibration such as engine shake that is input when traveling and high-frequency vibration such as traveling noise An effect is required.

  On the other hand, the anti-vibration effect based on the resonance action of the fluid flowing through the orifice passage is effectively exhibited against vibrations in the frequency range in which the orifice passage has been tuned in advance. Antivibration performance is greatly reduced for vibrations in a higher frequency range. Therefore, the applicant of the present invention previously disclosed in Japanese Patent Application Laid-Open No. 9-310732 (Patent Document 1) between the pressure receiving chamber and the equilibrium chamber in addition to the low frequency orifice passage between the pressure receiving chamber and the equilibrium chamber. In addition, a fluid-filled vibration isolator with a medium-frequency orifice passage and a high-frequency orifice passage was proposed. A movable member is disposed between the pressure receiving chamber and the equilibrium chamber, and a medium frequency orifice passage and a high frequency orifice passage are provided in parallel on the pressure receiving chamber side or the equilibrium chamber side of the movable member, and a valve for opening and closing the high frequency orifice passage. By providing a body and an actuator, three orifice passages tuned to different frequency ranges are selectively operated.

  However, in recent years, there has been a demand for further improvement of the vibration isolating performance along with the upgrading of automobiles, and further improvement in the performance of the fluid filled type anti-vibration device described in Patent Document 1 is desired. . Therefore, as a result of intensive studies aimed at further improving the vibration isolation performance, the present inventors have completed the present invention.

Japanese Patent Laid-Open No. 9-310732

  Here, the present invention has been made in the background as described above, and the problem to be solved is to prevent the complexity and cost of the structure from being reduced, and to prevent the resonance based on the resonance action of the sealed fluid. An object of the present invention is to provide a fluid filled type vibration damping device in which vibration performance is further improved.

  First, as for the fluid-filled vibration isolator described in the above-mentioned Patent Document 1, the present inventor has repeatedly studied. As a result, by increasing the amount of fluid flow through the medium frequency orifice passage through the high frequency orifice passage, the vibration damping performance is improved. It has been found that there is room for further improvement. That is, in the fluid-filled vibration isolator described in Patent Document 1, the movable member is arranged in series with respect to the medium frequency orifice passage and the high frequency orifice passage between the pressure receiving chamber and the equilibrium chamber. Therefore, the amount of fluid flow through the medium frequency orifice passage and the high frequency orifice passage may be reduced by the amount consumed as energy for displacing the movable member. Therefore, by reducing or avoiding energy consumption by this movable member, it is possible to increase the fluid flow amount of the medium frequency orifice passage and the high frequency orifice passage, thereby improving the vibration isolation performance. It came.

  Based on such a view, the first aspect of the present invention made to solve the above-described problem is that the first mounting member and the second mounting member are connected by the main rubber elastic body. A pressure receiving chamber in which a part of the wall is made of the main rubber elastic body and an equilibrium chamber in which a part of the wall is made of a flexible film are formed, and the pressure receiving chamber and the equilibrium chamber are not compressed. In the fluid-filled vibration isolator in which a low-frequency orifice passage is formed in which a pressure-sensitive fluid is sealed while the pressure-receiving chamber and the equilibrium chamber are communicated with each other, the low-frequency vibration is provided between the pressure-receiving chamber and the balance chamber. A fluid flow path is formed in parallel with the orifice passage, and is elastically held at a position separated from the opening portion to the pressure receiving chamber in the fluid flow path, by the action of the fluid flowing through the opening portion. An elastic valve body that closes the opening by being pressed against the opening On the other hand, a medium frequency orifice passage is provided on the opening side of the fluid flow path to the equilibrium chamber, and a leak hole for opening the fluid flow path to the equilibrium chamber is provided in the medium frequency orifice. It is characterized by a fluid-filled vibration isolator provided in parallel with the passage, and further provided with an on-off valve and an actuator for switching the leak hole between a communication state and a cutoff state.

  In the fluid-filled vibration isolator constructed according to this aspect, no movable member is provided for the fluid flow path provided in parallel with the low frequency orifice passage between the pressure receiving chamber and the equilibrium chamber. Therefore, between the pressure receiving chamber and the equilibrium chamber in an open state between the elastic valve disposed at the opening portion of the fluid flow path toward the pressure receiving chamber and the on-off valve disposed in the leak hole toward the equilibrium chamber. Free fluid flow at is acceptable.

  Therefore, when the medium frequency vibration is input, by closing the leak hole with the on-off valve, the fluid flow amount through the medium frequency orifice passage can be sufficiently secured in the fluid passage opened in the pressure receiving chamber, which is excellent. Anti-vibration effect is demonstrated. When high frequency vibration is input, the actuator is operated to open the leak hole, so that the fluid flow path is opened to both the pressure receiving chamber and the equilibrium chamber, and the generated pressure in the pressure receiving chamber is changed to the fluid flow path. By being escaped to the equilibrium chamber, an excellent vibration-proofing effect due to the low dynamic spring is exhibited. In particular, in any case, since the movable member as described in Patent Document 1 is not arranged in the fluid flow path, a sufficient amount of fluid flow through the medium frequency orifice passage and the fluid flow path can be secured, and The anti-vibration performance can be more effectively exhibited.

  Further, in the fluid-filled vibration isolator of this aspect, when the flow rate of the fluid flowing through the fluid flow path increases, the elastic valve element that operates with amplitude dependency closes the opening of the fluid flow path. Therefore, when the low-frequency large-amplitude vibration is input, the fluid flow path is blocked, so that a sufficient amount of fluid flow through the low-frequency orifice path can be ensured, and an excellent anti-vibration effect can be exhibited.

  As described above, in the fluid-filled vibration isolator of this aspect, the opening to the pressure receiving chamber side in the fluid flow path is controlled to open and close by the elastic valve element that operates with amplitude dependency, thereby opening and closing the opening. Therefore, an actuator and control means are not required separately, and the structure is not complicated.

  According to a second aspect of the present invention, in the fluid-filled vibration isolator according to the first aspect, the elastic member is formed at the opening portion of the fluid flow path to the pressure receiving chamber and protruding into the pressure receiving chamber. The elastic valve body is constituted by a projecting piece.

  In the fluid-filled vibration isolator of this aspect, the elastic valve body that operates with amplitude dependency based on the elasticity of the elastic protrusion can be realized with a simple structure. Preferably, the elastic protrusion is formed of a rubber elastic body, but it may be formed of an elastic metal piece, and a buffer rubber or the like is disposed on the contact portion of the metal piece with the opening. By providing, it is possible to improve the sealing performance when the fluid flow path is closed by the metal piece, and to reduce the hitting sound or the like associated with the hit.

  According to a third aspect of the present invention, in the fluid-filled vibration isolator according to the first or second aspect, the opening portion of the fluid flow path to the pressure receiving chamber is formed by a communication hole that narrows the fluid flow path. The elastic valve bodies are respectively provided at the openings on both sides of the communication hole.

  In the fluid-filled vibration isolator of this aspect, the opening portion can be closed with amplitude dependency by the elastic valve body in both directions of the fluid flow direction through the fluid flow path. Therefore, it is possible to more reliably close the opening portion to the pressure receiving chamber of the fluid flow path than when an elastic valve body that closes only one side in the fluid flow direction is provided. Thus, the vibration-proof performance against low-frequency large-amplitude vibration can be further improved.

  According to a fourth aspect of the present invention, in the fluid filled type vibration damping device according to any one of the first to third aspects, a resonance frequency of the fluid flowing through the leak hole is transferred to the pressure receiving chamber of the fluid flow path. The resonance frequency of the fluid flowing through the leak hole is avoided in the vibration frequency range to be vibrated to be higher than the resonance frequency of the fluid flowing through the opening portion.

  In the fluid-filled vibration isolator of this aspect, the anti-resonance action of the leak hole is avoided in the vibration frequency range to be vibrated, and even through sufficiently high frequency range vibration, It is possible to achieve a low dynamic spring based on fluid flow. In particular, by setting the resonance frequency of the fluid in the leak hole in a higher frequency range than the resonance frequency of the fluid in the opening portion of the fluid flow path to the pressure receiving chamber, the elastic valve body provided in the opening portion of the pressure receiving chamber It is avoided that the fluid action is hindered by the anti-resonance action of the leak hole, and the desired closing operation of the opening portion by the elastic valve body can be more stably expressed. For example, when high-frequency vibration that requires a vibration isolation effect due to fluid flow through the fluid flow path is specified, the resonance frequency of the fluid at the opening to the pressure receiving chamber of the fluid flow path It is also possible to configure a high-frequency orifice passage by tuning to the above.

  In the fluid-filled vibration isolator constructed according to the present invention, there is no need to dispose a movable member with respect to the fluid flow path provided in parallel with the low frequency orifice passage. A sufficient amount of fluid flow through the provided medium frequency orifice passage can be ensured to obtain a further excellent vibration isolation effect.

  In addition, the elastic valve body that substantially closes the fluid flow path when inputting low-frequency large-amplitude vibration is opened and closed using the amplitude dependence of the input vibration without requiring a special actuator. An anti-vibration effect based on fluid flow through the low-frequency orifice passage against low-frequency vibration can be effectively obtained with a simple structure.

It is a longitudinal cross-sectional view which shows the fluid enclosure type vibration isolator as one Embodiment of this invention, Comprising: II sectional drawing in FIG. II-II sectional drawing in FIG. III-III sectional drawing in FIG. The top view of the elastic valve member which comprises the fluid enclosure type vibration isolator shown by FIG. Explanatory drawing of the operation state of the elastic valve body in the fluid enclosure type vibration isolator shown by FIG. The model figure which shows the operation state in the idling state at the time of a vehicle stop in the fluid enclosure type vibration isolator shown in FIG. The model figure which shows the operation state in the fine amplitude vibration input state at the time of vehicle travel in the fluid enclosure type vibration isolator shown in FIG. The model figure which shows the operation state in the large amplitude vibration input state at the time of vehicle travel in the fluid enclosure type vibration isolator shown in FIG.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIGS. 1 to 3 show a fluid-filled vibration isolator 10 as an embodiment of the present invention. A fluid-filled vibration isolator 10 according to the present embodiment is an engine mount for an automobile, and includes a first mounting member 12 as a first mounting member and a second mounting member 14 as a second mounting member. Are elastically connected by the main rubber elastic body 16. The first mounting bracket 12 is attached to the power unit, and the second mounting bracket 14 is attached to the vehicle body, so that the power unit is elastic to the vehicle body by being interposed between the power unit and the vehicle body. It is designed to support vibration isolation. In the following description, the vertical direction means, in principle, the vertical direction in FIG. 1 which is the mount central axis direction. In addition, when the fluid-filled vibration isolator 10 is mounted on the vehicle, main vibration to be vibrated is input in the direction of the mount center axis between the first mounting bracket 12 and the second mounting bracket 14. The Rukoto.

  More specifically, the first mounting bracket 12 has a substantially circular rod shape whose lower portion is tapered to have a small diameter, and is a highly rigid member formed of metal or the like. Further, a flange portion 18 that extends to the outer peripheral side is integrally formed at the upper end portion of the first mounting bracket 12. Further, the first mounting bracket 12 is integrally formed with a bolt fixing portion 20 that protrudes further upward from the upper end portion where the flange portion 18 is formed. The bolt fixing portion 20 has a central axis extending from the upper end surface. Bolt holes extending downward are formed.

  On the other hand, the second mounting bracket 14 has a large-diameter, generally cylindrical shape as a whole, and is a highly rigid member like the first mounting bracket 12. Further, an annular step portion 22 is formed at an axially intermediate portion of the second mounting bracket 14, and the upper side is a large diameter cylindrical portion 24 across the step portion 22 and the lower side is a small diameter cylindrical portion. 26. Further, a caulking piece 28 is integrally formed at the lower end portion of the small diameter cylindrical portion 26.

  The first mounting bracket 12 is disposed on substantially the same central axis so as to be separated from the upper opening side of the second mounting bracket 14, and the first mounting bracket 12 and the second mounting bracket 14. Are elastically connected by the main rubber elastic body 16. The main rubber elastic body 16 has a large-diameter, generally frustoconical shape, and is fixed in a state where the first mounting bracket 12 is embedded from the end surface on the small-diameter side, and the outer periphery of the end portion on the large-diameter side. The large-diameter cylindrical portion 24 of the second mounting bracket 14 is overlapped and fixed to the surface. In the present embodiment, 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, an inverted mortar-shaped large-diameter recess 30 is formed in the large-diameter side end face of the main rubber elastic body 16. Furthermore, an annular seal rubber 32 extending into the small-diameter cylindrical portion 26 of the second mounting bracket 14 is integrally formed on the outer peripheral edge of the large-diameter side end surface of the main rubber elastic body 16. It is fixed to the inner peripheral surface of the upper end.

  Further, a partition member 34 is assembled to the lower end portion of the second mounting bracket 14. The partition member 34 is formed of a highly rigid member such as a metal or a synthetic resin, and has a thick, generally disc shape as a whole, and upper and lower annular latches extending in the circumferential direction on the outer peripheral surface. Grooves 36 and 38 are formed at a predetermined distance in the axial direction. The upper portion of the partition member 34 in the axial direction is fitted into the small-diameter cylindrical portion 26 of the second mounting bracket 14, and the second mounting bracket 14 is caulked with respect to the upper annular locking groove 36 of the partition member 34. 28 is fitted and locked. Accordingly, the partition member 34 is fixed to the lower end portion of the second mounting bracket 14, and the lower opening of the second mounting bracket 14 is covered with the partition member 34.

  In addition, a diaphragm 40 as a flexible film is disposed below the partition member 34. The diaphragm 40 is formed of a thin rubber film having a substantially disc shape, and has a large-diameter shallow bag shape opening upward. The diaphragm 40 is formed with sufficient slackness in the radial direction, and is easily deformed by expanding and contracting in the depth direction. In particular, in the present embodiment, the central portion of the diaphragm 40 is slightly thickened to increase the deformation rigidity, whereby the disc-shaped on-off valve 42 is integrally formed with the diaphragm 40.

  Furthermore, a cylindrical fixing bracket 44 is vulcanized and bonded to the outer peripheral edge of the diaphragm 40. Then, the upper end portion of the fixing bracket 44 is extrapolated to the lower end portion of the partition member 34, and the caulking piece 46 formed in the upper opening of the fixing bracket 44 is fitted into the lower annular locking groove 38 of the partition member 34. It is locked. As a result, the upward opening of the diaphragm 40 is covered with the partition member 34.

  Note that a seal rubber 48 sandwiched between the partition member 34 and the caulking piece 46 is integrally formed with the diaphragm 40 on the inner peripheral surface of the caulking piece 46 fitted on the partition member 34. In order to lock and fix the caulking pieces 28 and 46 of the second mounting bracket 14 and the fixing bracket 44 to the upper and lower annular locking grooves 36 and 38 of the partition member 34, This can be done by reducing the diameter of the inserted second mounting bracket 14 or fixing bracket 44 by eight-way drawing or the like.

  Thereby, the fixing bracket 44 fixed to the outer peripheral edge of the diaphragm 40 is fixedly connected to the lower side in the axial direction of the second mounting bracket 14 via the partition member 34. An incompressible fluid such as water or alkylene glycol is partitioned from the external space between the main rubber elastic body 16 and the diaphragm 40 opposed to each other in the mount axis direction with the partition member 34 interposed therebetween. An enclosed fluid chamber is defined.

  Further, the fluid chamber is divided into upper and lower sides by a partition member 34. Above the partition member 34, a pressure receiving chamber 50 in which a part of the wall portion is constituted by the main rubber elastic body 16 is formed. On the other hand, below the partition member 34, an equilibrium chamber 52 in which a part of the wall portion is constituted by the diaphragm 40 is formed. In the pressure receiving chamber 50, vibration is input as the main rubber elastic body 16 is elastically deformed when vibration is input, and pressure fluctuation is caused. On the other hand, in the equilibrium chamber 52, the volume change is easily allowed based on the deformation of the diaphragm 40, so that the internal pressure is maintained near the atmospheric pressure.

  Furthermore, the partition member 34 that partitions the fluid chamber to define the pressure receiving chamber 50 and the equilibrium chamber 52 is formed with a plurality of passages or flow paths that communicate the pressure receiving chamber 50 and the equilibrium chamber 52 with each other. . Then, when the fluid-filled vibration isolator 10 is mounted on the vehicle, the vibration input between the first mounting bracket 12 and the second mounting bracket 14 causes the pressure between the pressure receiving chamber 50 and the equilibrium chamber 52. As a relative pressure difference is induced, fluid flow through these passages or channels is generated.

  That is, the partition member 34 is formed with a circumferential groove 54 that extends near the outer periphery in the circumferential direction with a length of a little less than one round and opens upward. Then, on the upper surface of the partition member 34, a flat plate-shaped upper cover member 56 formed of a highly rigid member such as metal or synthetic resin is overlapped like the partition member 34, and the circumferential groove 54 is covered. A fluid passage is formed. The fluid passage extends in the circumferential direction by a predetermined length, and one end portion in the circumferential direction communicates with the pressure receiving chamber 50 through a communication window 57a provided in the upper lid member 56, and the other end portion in the circumferential direction. Is communicated with the equilibrium chamber 52 through a communication window 57 b provided in the partition member 34. As a result, the pressure receiving chamber 50 and the equilibrium chamber 52 communicate with each other through the fluid passage. Furthermore, the passage length and cross-sectional area of the fluid passage are adjusted, and the damping effect based on the resonance action of the fluid flowing inside is tuned so as to be exhibited against low frequency vibration such as engine shake. A low frequency orifice passage 58 is formed.

  In addition, a fluid flow path 60 extending in parallel with the low frequency orifice passage 58 is formed between the pressure receiving chamber 50 and the equilibrium chamber 52 in the central portion of the partition member 34. The fluid flow path 60 is formed through a large-diameter circular upper and lower recesses 62 and 64 formed on both upper and lower surfaces of the central portion of the partition member 34 and a partition wall 66 between the upper and lower recesses 62 and 64. The central through-hole 68 and the upper and lower through-holes 72 and 74 formed through the flat plate-shaped upper and lower lid members 56 and 70 covering the upper and lower recesses 62 and 64, respectively. The lower lid member 70 is formed of a highly rigid member such as a metal or a synthetic resin, like the partition member 34 and the upper lid member 56.

  Further, an elastic valve member 76 made of a thick rubber elastic body is incorporated in the upper recess 62 of the partition member 34 in the accommodated state, and is attached to the bottom surface of the upper recess 62 of the partition member 34 and the upper lid member 56. On the other hand, the upper and lower surfaces are arranged in close contact with each other. As shown in FIG. 4 showing a single elastic valve member 76, an annular seal lip extending in the circumferential direction protrudes from the outer peripheral edge of the elastic valve member 76. Fluid leakage around the surface is prevented.

  As shown in FIGS. 1 and 4, the elastic valve member 76 has a communication hole 78 penetrating in the plate thickness direction and having a slit-like planar shape extending substantially linearly with a predetermined width. Yes. The formation position and number of the communication holes 78 are not particularly limited, but in the present embodiment, three communication holes 78, 78, 78 extending in parallel with each other are formed.

  In the present embodiment, the upper through holes 72 of the upper lid member 56 are provided at positions corresponding to the upper openings of the communication holes 78 and positions corresponding to the lower openings of the communication holes 78. Each central through hole 68 of the partition wall 66 is provided. The upper through-hole 72 and the central through-hole 68 have a shape that linearly extends with a predetermined width, like the communication holes 78, and are formed with an opening that is slightly larger than the communication holes 78. In short, the fluid flow path 60 in the upper recess 62 of the partition member 34, that is, the opening portion of the fluid flow path 60 to the pressure receiving chamber 50 is narrowed by the communication hole 78 of the elastic valve member 76, and the communication is substantially performed. The fluid channel 60 in the upper recess 62 is constituted by the hole 78.

  In addition, each communication hole 78 in the elastic valve member 76 extends with a substantially constant width dimension and cross-sectional area. In the present embodiment, the communication hole 78 penetrates with a slight inclination with respect to the thickness direction of the elastic valve member 76. Yes. Further, as shown in an enlarged view in FIG. 5A, in each communication hole 78, one wall portion in the slit width direction which is the left-right direction in FIGS. A hollow upper concave groove 80 that is opened in this manner is formed along the communication hole 78 over the entire length in the slit length direction. As a result, one wall portion in the slit width direction of the communication hole 78 protrudes upward along the communication hole 78, and is an upper side on the pressure receiving chamber 50 side of the fluid flow path 60 formed by the communication hole 78. An upper elastic valve body 82 that is elastically held at a position separated from the opening portion without covering the opening is integrally formed with the elastic valve member 76.

  On the other hand, in the other wall portion in the slit width direction, a hollow-shaped lower concave groove 84 that opens downward is formed along the communication hole 78 over the entire length in the slit length direction. Accordingly, the other wall portion in the slit width direction of the communication hole 78 protrudes downward along the communication hole 78, with respect to the downward opening portion of the fluid flow path 60 formed by the communication hole 78. A lower elastic valve body 86 that is elastically held at a separated position without covering the opening is integrally formed with the elastic valve member 76.

  Both the upper elastic valve body 82 and the lower elastic valve body 86 are gradually made thinner from the base end portion toward the distal end side, and are integrally formed with the elastic valve member 76. Further, an upper seal protruding upward at a height smaller than that of the upper elastic valve body 82 is provided at an opening edge located on the opposite side of the upper elastic valve body 82 across the upper opening of the communication hole 78 in the slit width direction. The protrusion 88 is integrally formed over the entire length in the slit length direction. Furthermore, the opening end edge located on the opposite side of the lower elastic valve body 86 across the lower opening of the communication hole 78 in the slit width direction protrudes downward at a height smaller than that of the lower elastic valve body 86. The lower seal protrusion 90 is integrally formed over the entire length in the slit length direction.

  The upper elastic valve body 82 and the lower elastic valve body 86 are adapted to act on the pressure accompanying the fluid flow through the fluid flow path 60. While the amount of fluid flow is small, the upper and lower elastic valve bodies 82 and 86 substantially maintain their initial shapes based on their deformation rigidity and are separated from the opening of the communication hole 78 that constitutes the fluid flow path 60. However, when the amount of fluid flow increases, the upper and lower elastic valve bodies 82 and 86 are elastically deformed toward the opening side of the communication hole 78 so as to yield to the working pressure. That is, the upper and lower elastic valve bodies 82 and 86 are elastically deformed with an amplitude dependency with respect to the input vibration that causes fluid flow and thus pressure fluctuation.

  Therefore, when the amount of fluid flow in the direction from the pressure receiving chamber 50 to the equilibrium chamber 52 (direction A in FIG. 5A) in the communication hole 78, that is, the fluid flow path 60, increases as shown in FIG. 5B. As shown, the upper elastic valve body 82 is elastically deformed so as to fall to the communication hole 78 side due to the pressure difference exerted on both surfaces thereof, and the vicinity of the tip of the upper elastic valve body 82 abuts against the upper seal protrusion 88 on the opposite bank. . As a result, the communication hole 78 formed so as to narrow the opening of the fluid flow channel 60 to the pressure receiving chamber 50 is closed by pressing the upper elastic valve body 82 against the upper opening. .

  Further, in the communication hole 78, that is, the fluid flow path 60, when the amount of fluid flow in the direction from the equilibrium chamber 52 toward the pressure receiving chamber 50 (the B direction in FIG. 5A) increases, it is shown in FIG. As described above, the lower elastic valve body 86 is elastically deformed so as to fall to the communication hole 78 side due to the pressure difference exerted on both surfaces thereof, and the vicinity of the tip of the lower elastic valve body 86 becomes the lower seal protrusion 90 on the opposite bank. Abut. As a result, the communication hole 78 formed so as to narrow the opening to the pressure receiving chamber 50 in the fluid flow path 60 is closed by pressing the lower elastic valve body 86 against the lower opening. Become.

  In particular, in the present embodiment, the upper and lower elastic valve bodies 82 and 86 are provided at the opening portion of the communication hole 78 formed by constricting the fluid flow path 60 to increase the fluid flow rate, and The upper and lower concave grooves 80 and 84 are formed behind the elastic valve bodies 82 and 86 to increase the working area of the fluid pressure, and the communication hole 78 is formed with a central axis inclined with respect to the mount central axis. Since the upper and lower elastic valve bodies 82 and 86 are also formed so as to be inclined and projecting in the direction of closing the communication hole 78, the pressure accompanying the fluid flow is more effective for the upper and lower elastic valve bodies 82 and 86. As a result, the opening / closing operation depending on the amplitude of the upper and lower elastic valve bodies 82 and 86 can be realized more reliably.

  On the other hand, a large-diameter leak hole 92 is formed in the center portion of the lower lid member 70 which is overlapped and fixed so as to cover the opening of the lower recess 64 of the partition member 34, so that the fluid flow The path 60 is open to the equilibrium chamber 52. In addition, an intermediate frequency orifice passage 94 including a lower through hole 74 that penetrates the lower lid member 70 with a smaller area than the leak hole 92 is formed around the leak hole 92.

  The medium frequency orifice passage 94 has a length of the through hole so that a vibration insulation effect by low dynamic springs against medium frequency vibration such as idling vibration of an automobile is exhibited based on the resonance action of the fluid flowing through the inside. The sheath area is set. In the present embodiment, the medium frequency orifice passage 94 is configured by the plurality of lower through holes 74, but the number and shape of the through holes are not limited.

  On the other hand, the leak hole 92 is formed with an opening area larger than that of the medium frequency orifice passage 94, and the value of the ratio (A / L) of the flow path cross-sectional area A to the flow path length L is the elastic valve member 76. It is made larger than the communication hole 78 formed in this. As a result, the resonance frequency of the fluid flowing through the leak hole 92 is set to a higher frequency range that exceeds the frequency range of vibration that requires vibration isolation, and the leak hole 92 in the vibration frequency range to be isolated is provided. Fluid resonance in is avoided. That is, substantial blockage of the leak hole 92 due to the anti-resonant action of the fluid flowing through the leak hole 92 is avoided.

  The communication hole 78 formed in the elastic valve member 76 is also tuned to a higher frequency range so that the resonance action of the fluid in the frequency range of vibration to be vibrated is avoided, similarly to the leak hole 92. However, in the present embodiment, the tuning is performed in a high frequency range corresponding to the traveling noise of the automobile. Then, based on the resonance action of the fluid flowing through the communication hole 78, the vibration insulation effect by the low dynamic spring against the high frequency vibration such as the running noise of the automobile is exhibited.

  In the partition member 34 having such a structure, it is located at the opening side portion to the pressure receiving chamber 50 on the fluid flow path 60 and includes a communication hole 78 having upper and lower elastic valve bodies 82 and 86 at the opening. A high-frequency orifice passage is formed, and a medium-frequency orifice passage 94 and a leak hole 92 are arranged in parallel with each other in the communication hole 78 in the opening side portion to the equilibrium chamber 52 on the fluid flow path 60. In contrast, they are formed in series.

  Further, a negative pressure actuator 96 as an actuator is disposed outside the equilibrium chamber 52 formed below the partition member 34 and positioned below the diaphragm 40. The negative pressure actuator 96 includes a housing bottom fitting 98 having a large-diameter, generally cup shape, and the peripheral wall on the opening side of the housing bottom fitting 98 has a small diameter cylindrical portion 26 and a fixing fitting 44 of the second mounting fitting 14. Is fitted and fixed. The external fitting and fixing of the housing bottom bracket 98 to the second mounting bracket 14 and the fixing bracket 44 can be performed by diameter reduction processing as well as press-fitting processing.

  In addition, an output member 100 having a substantially hat shape with a small diameter and made of metal or the like is disposed in a housed state inside the housing bottom metal fitting 98 at the center near the bottom. Further, an annular fitting 102 is disposed on the outer peripheral side of the output member 100, and the hook-shaped portion provided on the opening peripheral edge of the output member 100 and the fitting 102 are thick. They are connected by a connecting rubber elastic body 104 having a substantially annular plate shape or a substantially disc spring shape. The fitting metal fitting 102 is fitted into the housing bottom metal fitting 98 and is fitted and fixed to the outer peripheral wall of the bottom portion, so that the external surface between the bottom wall of the housing bottom metal fitting 98 and the output member 100 is exposed to the outside. A working air chamber 106 that is blocked in this manner is defined.

  The working air chamber 106 is accommodated and disposed on the central axis in a state where the compression coil spring 108 extends in the vertical direction, and the output member 100 is always separated upward from the housing bottom metal fitting 98. Energizing force is exerted. Furthermore, a supply / exhaust port 110 penetrating inward and outward is provided in the center of the bottom wall of the housing bottom fitting 98, and air pressure is applied to the working air chamber 106 through the supply / exhaust port 110.

  A specific pneumatic circuit connected to the supply / exhaust port 110 may be a well-known one, and is not shown. For example, for a negative pressure source such as an intake negative pressure of an internal combustion engine or a negative pressure pump. Thus, a pneumatic circuit connected to the supply / exhaust port 110 of the negative pressure actuator 96 via an accumulator or the like is employed as necessary. This pneumatic circuit is provided with a control valve that controls conduction of the negative pressure source to the supply / discharge port 110. The working air chamber 106 is selectively switched between the negative pressure source and the atmosphere by a controller that switches and controls the control valve with reference to a sensor output or the like that detects the running state of the automobile.

  In a state where the working air chamber 106 is connected to the atmosphere, the output member 100 of the negative pressure actuator 96 is biased upward by the compression coil spring 108. As a result, the upper bottom portion of the output member 100 is brought into contact with the on-off valve 42 formed at the central portion of the diaphragm 40, and the on-off valve 42 is pressed against the central portion of the partition member 34 from the lower surface. Is supposed to be retained.

  In the present embodiment, the connecting rubber elastic body 104 is formed as an integrally vulcanized molded product including the output member 100 and the fitting fitting 102, and covers the entire surface of the output member 100. 112 is integrally formed with the connecting rubber elastic body 104. A cushioning rubber that extends over the entire contact surface with the on-off valve 42 is formed on the upper surface of the upper bottom portion of the output member 100 by the covering rubber layer 112.

  On the other hand, under the state where the working air chamber 106 is connected to the negative pressure source, the output member 100 of the negative pressure type actuator 96 is attracted downward by the negative pressure against the urging force of the compression coil spring 108 and displaced. Thereby, the force which presses the on-off valve 42 of the diaphragm 40 against the partition member 34 is released, and the on-off valve 42 is separated downward from the partition member 34. The upper bottom portion of the output member 100 may be bonded to the diaphragm 40 or may be separated from each other without being bonded.

  Therefore, when the working air chamber 106 of the negative pressure actuator 96 is communicated with the atmosphere, the center portion of the diaphragm 40 is pushed upward at the upper bottom portion of the output member 100, thereby causing a leak hole 92 formed in the partition member 34. The on-off valve 42 is pressed against the lower opening of the lower end of the leak hole 92 so that the leak hole 92 is kept closed. On the other hand, when the working air chamber 106 of the negative pressure type actuator 96 is in a negative pressure communication state, the pressing force applied to the diaphragm 40 by the output member 100 is released, and the on-off valve 42 is separated from the lower opening of the leak hole 92. Thus, the leak hole 92 is kept in communication.

  Note that the size of the pressing region of the on-off valve 42 that is pressed against the bottom surface of the partition member 34 by the output member 100 of the negative pressure actuator 96 is the entire lower opening of the leak hole 92 of the partition member 34. It is a substantially circular region that is covered and pressed against the peripheral edge of the lower opening with fluid tightness. In addition, the size and shape of the outer peripheral edge of the pressing region are set so that the pressing region is kept in a communicating state without covering the intermediate frequency orifice passage 94 of the partition member 34 while being pressed by the partition member 34. .

  The fluid-filled vibration isolator 10 having such a structure selectively changes the vibration isolating characteristics by switching the connection state of the negative pressure actuator 96 to the atmosphere and the negative pressure source while being mounted on an automobile. It is possible to obtain the desired vibration isolation performance by switching.

  Specifically, for example, by using a speed sensor signal or a gear shift position sensor signal of an automobile, the negative pressure actuator 96 is held in communication with the atmosphere in a stopped state, while in the traveling state of the automobile, a negative pressure type is used. The actuator 96 is held in communication with the negative pressure source.

  Thereby, first, when the automobile is stopped, the leak hole 92 of the fluid flow path 60 is closed by the on-off valve 42 as schematically shown in FIG. 6, and the pressure receiving chamber 50 and the equilibrium chamber 52 are The low-frequency orifice passage 58 and the fluid flow path 60 configured to connect the communication hole 78 and the medium-frequency orifice passage 94 in series are in parallel communication with each other. With respect to the idling vibration in the middle frequency range of about 20 to 40 Hz input under such a state, the low frequency orifice passage 58 is substantially closed due to a marked increase in flow resistance due to anti-resonance action. Therefore, based on the pressure difference induced between the pressure receiving chamber 50 and the equilibrium chamber 52, the fluid flow through the fluid channel 60 is induced exclusively.

  Here, the communication hole 78 on the fluid flow path 60 is not only tuned to a frequency at which anti-resonance action does not occur up to a high frequency range or higher frequency range, but also there is a fluid flow such as a movable member. Since there are no obstacles on the road, there is almost no flow resistance in the middle frequency range. Therefore, the amount of fluid flow through the medium frequency orifice passage 94 can be sufficiently secured, and the vibration isolation effect based on the fluid action such as the resonance action of the fluid can be effectively exhibited against idling vibration.

  On the other hand, in the traveling state of the automobile, as shown in FIGS. 7 and 8 as a model, the on-off valve 42 is separated from the leak hole 92 of the fluid flow path 60 and the leak hole 92 is opened. As a result, between the pressure receiving chamber 50 and the equilibrium chamber 52, the medium frequency orifice passage 94 and the leak hole 92, which are provided in parallel with each other on the fluid flow path 60, are both opened and similarly opened. It will be in the state connected in series with respect to the communication hole 78 made into the state.

  Under such a condition, when high-frequency vibration such as a running-over noise of about 60 to 150 Hz caused by contact between the road surface and tires during running or engine vibration is input, as shown in the model diagram of FIG. Since both the low frequency orifice passage 58 and the medium frequency orifice passage 94 are substantially closed by the anti-resonance action, the communication hole is exclusively based on the pressure difference caused between the pressure receiving chamber 50 and the equilibrium chamber 52. The fluid flow on the fluid flow path 60 is caused from the leak hole 92 from 78.

  Here, both the communication hole 78 and the leak hole 92 on the fluid flow path 60 are tuned so as not to cause anti-resonance in the frequency range of the high-frequency vibration, so that the pressure fluctuation in the pressure receiving chamber 50 is promptly changed. The pressure fluctuation in the pressure receiving chamber 50 is eliminated by the escape to the equilibrium chamber 52. As a result, an excellent vibration insulating action, that is, an anti-vibration action due to the low dynamic spring effect is exhibited against high frequency vibration. In particular, the communication hole 78 on the fluid flow path 60 is not provided with an obstacle on the fluid flow path such as a movable member, and hardly causes flow resistance in a high frequency range having a minute amplitude. Therefore, the anti-vibration effect based on the pressure releasing action from the pressure receiving chamber 50 to the equilibrium chamber 52 through the fluid flow channel 60 can be effectively exerted against high-frequency vibration such as traveling noise.

  Further, the communication hole 78 can be tuned to a high frequency range, thereby obtaining a further low dynamic spring action based on the resonance action of the fluid flowing through the communication hole 78 against high frequency vibrations. It is also possible to further improve the anti-vibration performance. Even in that case, the fluid flow rate 60 is sufficiently tuned to the higher frequency range so as to prevent the anti-resonance effect including the leak hole 92 on the fluid flow path 60, so that the amount of fluid flow through the communication hole 78 is sufficient. Therefore, the communication hole 78 can effectively function as a high-frequency orifice passage, so that an excellent vibration-proofing effect against high-frequency vibration can be obtained.

  On the other hand, when low-frequency vibration such as shake vibration accompanying stepping over a step is input when the vehicle travels, such low-frequency vibration generally has a large amplitude of 10 times or more compared to idling vibration or traveling noise. Therefore, the upper and lower elastic valve bodies 82 and 86 of the elastic valve member 76 operating with amplitude dependency are elastically deformed, and the communication holes 78 are formed as shown in FIGS. 5B and 5C. Blocked. As a result, as shown in the model diagram of FIG. 8, the fluid flow path 60 is substantially blocked, and the low-frequency orifice is based on the relative pressure fluctuation between the pressure receiving chamber 50 and the equilibrium chamber 52. The fluid flow through the passage 58 can be sufficiently ensured, and excellent vibration-proof performance is exhibited by the high damping effect based on the resonance action of the fluid.

  Therefore, in the fluid filled type vibration damping device 10 of this embodiment, the leak hole 92 is brought into the communication / blocking state using the on-off valve 42 and the negative pressure type actuator 96 against vibrations in different states during traveling and when the vehicle is stopped. By switching, it is possible to exhibit excellent anti-vibration performance in both the running state and the stopped state. Further, by providing elastic valve bodies 82 and 86 having amplitude dependency with respect to vibrations having different amplitudes such as a fine amplitude and a large amplitude during traveling, the communication hole 78 is provided at the time of the fine amplitude and the large amplitude. By switching to the communication / blocking state, it is possible to obtain an excellent vibration-proofing performance for both fine amplitude vibration and large amplitude vibration.

  In the present embodiment, elastic valve bodies 82 and 86 having amplitude dependency are employed as switching means for communicating / blocking the communication hole 78 constituting the fluid flow path 60, and the communication hole 78 is connected / blocked. The state is automatically switched based on the amplitude of the input vibration. Therefore, for example, it is not necessary to separately provide an actuator or the like when switching the communication state / blocking state of the communication hole 78, so that the structure of the switching means for the fluid flow path 60 and the vibration isolator can be simplified. An increase in the size of the vibration isolator can be avoided.

  As mentioned above, although embodiment of this invention has been explained in full detail, this invention is not limited at all by the specific description in this embodiment. For example, the upper and lower elastic valve bodies 82 and 86 in the above embodiment can be formed with different elasticity, different shapes, or the like, and it is also possible to provide only one of the upper and lower elastic valve bodies. It is. By adjusting the characteristics of the upper and lower elastic valve bodies 82 and 86 in this way, it becomes possible to tune more variously to the input vibration. For example, the vibration isolation effect based on the fluid flow can be broadened. It can also be used in a wide frequency range. The upper and lower elastic valve bodies 82 and 86 do not need to be integrally formed with the elastic valve member 76 accommodated in the partition member 34 as in the above-described embodiment. For example, the central through hole 68 and the upper through hole 72 are not required. It is also possible to form the elastic valve bodies 82 and 86 by a rubber elastic piece or the like that is fixed to the opening edge of each other and protrudes from the opening edge of the central through hole 68 or the upper through hole 72 in the fluid flow direction. . Thus, in the present invention, if the communication hole 78 and the elastic valve bodies 82 and 86 are formed, the upper recess 62 in which the elastic valve member 76 and the elastic valve member are accommodated is not necessarily required.

  In the above-described embodiment, the upper and lower elastic valve bodies 82 and 86 are formed of rubber elastic bodies. However, it is also possible to configure the elastic valve bodies by leaf springs made of elastic metal or resin. . Specifically, for example, an elastic protruding piece made of, for example, a plate-like metal spring is adopted, and the base end portion of the fluid flow channel 60 is opened to the pressure receiving chamber 50 side, that is, the upper through hole formed in the upper lid member 56. 72 is fixed to the peripheral edge of the opening. Then, a tip valve portion larger than the opening of the upper through hole 72 is provided on the free end side of the elastic protruding piece, and the tip valve portion is protruded into the pressure receiving chamber 50 so that the pressure receiving chamber in the upper through hole 72 is provided. 50 is spaced over the opening into 50. As a result, the fluid pressure flowing through the upper through-hole 72 of the fluid flow path 60 acts on the front and back of the tip valve portion of the elastic projection piece, and the fluid pressure difference exerted on both surfaces of the elastic projection piece with amplitude dependency Based on the above, the fluid channel 60 can be controlled to be communicated / blocked by the elastic protrusion.

  When such an elastic protruding piece is employed, it is desirable that the sealing rubber is fixed to the contact surface of the elastic protruding piece with the opening peripheral edge of the communication hole 78. As a result, the communication hole 78 can be reliably blocked, and the hitting sound and vibration associated with the contact of the elastic protruding piece can be reduced.

  The present invention is also applicable to engine mounts other than those for automobiles, and subframe mounts and body mounts for vehicles other than engine mounts.

10: fluid-filled vibration isolator, 12: first mounting bracket, 14: second mounting bracket, 16: rubber elastic body of main body, 40: diaphragm, 42: on-off valve, 50: pressure receiving chamber, 52: equilibrium chamber 58: Low frequency orifice passage, 60: Fluid passage, 78: Communication hole, 82: Upper elastic valve body, 86: Lower elastic valve body, 92: Leak hole, 94: Medium frequency orifice passage, 96: Negative pressure type Actuator

Claims (4)

The first mounting member and the second mounting member are connected by a main rubber elastic body, and a pressure receiving chamber in which a part of the wall portion is configured by the main rubber elastic body and a part of the wall portion are flexible. An equilibrium chamber composed of a membrane is formed, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, while a low frequency orifice passage is formed to communicate the pressure receiving chamber and the equilibrium chamber with each other. In a fluid-filled vibration isolator,
A fluid flow path is formed in parallel with the low frequency orifice passage between the pressure receiving chamber and the equilibrium chamber,
Elasticity that closes the opening portion by being elastically held at a position separated from the opening portion to the pressure receiving chamber in the fluid flow path and pressed against the opening portion by the action of fluid flowing through the opening portion. While the valve body is provided,
An intermediate frequency orifice passage is provided on the fluid channel on the opening side to the equilibrium chamber, and a leak hole for opening the fluid passage to the equilibrium chamber is provided in parallel with the intermediate frequency orifice passage. In addition,
An on-off valve and an actuator for switching the leak hole between a communication state and a shut-off state and an actuator are provided.   2. The fluid filled type vibration damping device according to claim 1, wherein the elastic valve body is configured by an elastic protruding piece that is positioned at an opening portion of the fluid flow path to the pressure receiving chamber and protrudes into the pressure receiving chamber. .   The opening part to the said pressure receiving chamber in the said fluid flow path is comprised by the communicating hole which narrows this fluid flow path, The said elastic valve body is each provided in the opening part of the both sides of this communicating hole. Or the fluid-filled vibration isolator according to 2.   The resonance frequency of the fluid flowing through the leak hole is made higher than the resonance frequency of the fluid flowing through the opening portion of the fluid flow path to the pressure receiving chamber. The fluid-filled vibration isolator according to any one of claims 1 to 3, wherein a resonance phenomenon of a flowing fluid is avoided.

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