JP4792417B2 - Fluid filled vibration isolator - Google Patents

Description

  The present invention relates to an anti-vibration device used as, for example, an automobile engine mount, and more particularly to a fluid-filled vibration-proof device that utilizes an anti-vibration effect based on a fluid action of a fluid enclosed inside.

  2. Description of the Related Art Conventionally, as a type of vibration isolator mounted between members constituting a vibration transmission system, a fluid-filled vibration isolator that obtains a vibration isolating effect by using a flow action of a fluid sealed inside is provided. Are known. The fluid-filled vibration isolator is, for example, a first attachment member attached to one member constituting a vibration transmission system, and one of the second attachment members attached to the other member and having a cylindrical portion. The first mounting member and the second mounting member are connected to each other by the main rubber elastic body, and the wall portions are arranged on both sides of the partition member supported by the second mounting member. A pressure receiving chamber, part of which is made of rubber elastic body, and an equilibrium chamber, part of which is made of a flexible membrane, are formed, and these pressure receiving chamber and equilibrium chamber are connected to each other by an orifice passage. Structure. At the time of vibration input, the vibration isolation effect can be obtained based on the resonance action of the fluid that is caused to flow through the orifice passage based on the relative pressure fluctuation caused between the pressure receiving chamber and the equilibrium chamber. .

  By the way, in such a fluid filled type vibration damping device, while the vibration damping effect based on the fluid flow action is effectively exhibited in the frequency range in which the orifice passage is tuned, at the time of vibration input in other frequency ranges, It is difficult to obtain an effective anti-vibration effect. On the other hand, the frequency range in which the anti-vibration effect is required for the anti-vibration device generally covers a plurality of or a wide frequency range. For example, an engine mount for automobiles is required to have an anti-vibration effect against low-frequency vibrations such as an engine shake during driving, while an anti-vibration effect against medium to high-frequency vibrations such as idling vibration is required when the vehicle is stopped. The Rukoto.

  Therefore, in order to exert a vibration isolation effect based on the fluid flow action against a plurality of vibrations in a wide frequency range, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2000-257665), a low A first orifice passage tuned in the frequency range and a second orifice passage tuned in the middle frequency range are formed, and a valve body for opening and closing the second orifice passage and the valve body are opened and closed. A switching type fluid-filled vibration isolator having a structure provided with an actuator has been proposed. Moreover, the fluid-filled vibration isolator disclosed in Patent Document 1 has a structure in which a movable member that separates the pressure-receiving chamber and the equilibrium chamber is arranged at a position different from the first and second orifice passages so as to be capable of minute displacement. Therefore, an effective anti-vibration effect can be exhibited even when vibration is input in a high frequency range by utilizing a hydraulic pressure absorbing action due to the displacement of the movable member. As a result, for example, low-frequency vibrations such as engine shakes, medium-frequency vibrations such as medium-frequency idling vibrations, and high-frequency vibrations such as high-frequency idling vibrations and booming sounds can be obtained. Can be done.

  However, further investigations and experiments by the present inventors have revealed that there is still room for improvement in the fluid-filled vibration isolator described in Patent Document 1. That is, in the fluid-filled vibration isolator disclosed in Patent Document 1, the second orifice passage tuned to a higher frequency range than the first orifice passage during running or the like where vibration in the low frequency range is likely to be a problem. By shutting off, the amount of fluid flow through the first orifice passage tuned to the low frequency range is effectively ensured, and the anti-vibration effect based on the fluid flow action is advantageously exhibited. However, in the structure described in Patent Document 1, the movable member provided at a position different from the first and second orifice passages is disposed in a state in which minute displacement is always allowed. Even if the second orifice passage is cut off, the hydraulic pressure in the pressure receiving chamber is released to the equilibrium chamber side by the minute displacement of the movable member. Therefore, the amount of fluid flow through the first orifice passage may be reduced, and the target vibration-proofing effect may not be exhibited effectively.

  In addition, even when the second orifice passage is communicated when the vehicle is stopped, the fluid flow amount through the second orifice passage cannot be effectively obtained by the fluid pressure absorbing action by the movable member. There was a possibility that the vibration proof performance could not be realized.

JP 2000-257665 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is to exhibit an excellent anti-vibration effect for input vibrations in different frequency ranges, In particular, an object of the present invention is to provide a fluid-filled vibration isolator having a novel structure capable of effectively obtaining a vibration isolating effect based on fluid flow through the first and second orifice passages.

  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.

That is, according to the present invention, the first mounting member is arranged separately on one opening side of the second mounting member provided with the cylindrical portion, and the first mounting member and the second mounting member are separated from the main rubber. The partition member is supported by the second mounting member while being connected by an elastic body, and a pressure receiving chamber in which a part of the wall portion is formed of the main rubber elastic body is formed on one side of the partition member. And forming an equilibrium chamber with a part of the wall made of a flexible membrane on the other side across the partition member, and enclosing the incompressible fluid in the pressure receiving chamber and the equilibrium chamber, A first orifice passage communicating the pressure receiving chamber and the equilibrium chamber with each other, and a second orifice passage tuned in a higher frequency range than the first orifice passage, while sandwiching the flexible membrane The actuator is disposed on the opposite side of the equilibrium chamber with the actuator. In the fluid filled type vibration damping device and capable of switching said second orifice passage to the blocking state the communicating state and use, by forming a recess in the central portion of the end face of the equilibrium chamber side of the partition member, the A communication hole extending from the inner peripheral surface of the recess toward the outer peripheral side of the partition member, and a communication path extending from the communication hole in the thickness direction of the partition member and opening to the end surface of the partition member on the pressure receiving chamber side the pressure receiving chamber and said equilibrium chamber cross to form a main flow path communicating with, and form a branch flow passage communicating with the receiving chamber branches at an intermediate portion of the communication passage in the main passage by the main flow while forming the second orifice passage comprises a road and the branch flow path, disposed micro displaceable and are movable member in the flow path of the branched flow path, said on one surface of the movable member The pressure in the pressure receiving chamber is made to act through the branch channel. Both as a pressure of the equilibrium chamber is caused to act through said main passage and said branch flow passage on the other side, further, the opening portion of the recess of the partition member, said flexible film The main flow path and the divided flow path constituting the second orifice passage are blocked simultaneously by being pressed by the actuator .

  In such a fluid-filled vibration isolator having the structure according to the present invention, the vibration isolating effect based on the fluid action of the fluid that flows between the pressure receiving chamber and the equilibrium chamber through the first and second orifice passages, and the movable member By virtue of the anti-vibration effect based on the hydraulic pressure absorbing action due to the minute displacement, it is possible to obtain an excellent anti-vibration effect against input vibrations in a plurality of or wide frequency ranges.

  Moreover, in the present invention, the second orifice passage is configured to include a main flow path and a branch flow path that branches at an intermediate portion in the flow path length direction of the main flow path. The branch flow paths are opened and communicated with the pressure receiving chambers separately, and are communicated with the equilibrium chamber through the same opening on the equilibrium chamber side. Therefore, by simply controlling the switching of the opening on the equilibrium chamber side of the second orifice passage between the communication state and the closed state by the operation of the actuator, it is only necessary to switch between the communication state and the shut-off state of the second orifice passage. In addition, the movable member can be switched between the allowable displacement state and the displacement restrained state at the same time.

  By such simple control, the communication / blocking of the second orifice passage and the displacement allowance / displacement constraint of the movable member can be switched at the same time. By closing the actuator and closing the second orifice passage, and restraining the displacement of the movable member, the fluid flow through the first orifice passage can be generated more advantageously, The intended vibration proofing effect can be exhibited effectively. In addition, when the vibration is input in the tuning frequency range of the second orifice passage or the movable member, the actuator is opened to bring the second orifice passage into a communication state and allow the displacement of the movable member. The anti-vibration effect by the fluid flow through the second orifice passage and the minute displacement of the movable member can be exhibited effectively.

  In the fluid-filled vibration isolator according to the present invention, the flow resistance exerted on the fluid that flows between the pressure receiving chamber and the equilibrium chamber through the main flow path is balanced with the pressure receiving chamber through the branch flow path. Desirably, it is greater than the flow resistance exerted on the fluid flowing between the chambers.

  According to this, under the communication state of the second orifice passage, an anti-vibration effect based on the hydraulic pressure absorbing action due to the minute displacement of the movable member is effectively exhibited. Therefore, when the vibration is input in the tuning frequency range of the movable member, the intended vibration isolation effect can be advantageously obtained.

  In the fluid filled type vibration damping device according to the present invention, the movable member is a movable rubber plate formed of a rubber elastic body, and the movable rubber plate is orthogonal to the flow path direction of the branch flow path. It may be arranged so as to widen and allow a minute displacement in the flow path direction of the branch flow path.

  By adopting such a movable rubber plate as a movable member, the hydraulic pressure absorbing action due to the minute displacement of the movable rubber plate and the hydraulic pressure absorbing action due to the minute deformation of the movable rubber plate formed of the elastic body are excellent. Anti-vibration effect can be realized.

  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, FIG. 1 shows an automotive engine mount 10 as an embodiment of a fluid filled type vibration damping device according to 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 to each other by a main rubber elastic body 16. Yes. The first mounting bracket 12 is attached to one member to be vibration-proof connected such as an automobile power unit (not shown), and the second mounting bracket 14 is connected to the other member to be vibration-proof connected such as an automobile body (not shown). By being attached to the member, the power unit is supported in a vibration-proof manner by the vehicle body.

  More specifically, the first mounting member 12 is a highly rigid member formed of a metal material such as iron or aluminum alloy, and has a substantially inverted truncated cone block shape. A mounting bolt 18 is integrally formed on the large-diameter side end surface of the first mounting bracket 12 so as to protrude upward in the axial direction.

  Similarly to the first mounting bracket 12, the second mounting bracket 14 is formed of a metal material such as iron or aluminum alloy, and has a large cylindrical shape as a whole. In addition, the second mounting bracket 14 includes a constricted portion 20 as an annular groove at the axially upper end thereof. The constricted portion 20 is recessed inward in the radial direction and extends in the circumferential direction. In this embodiment, the constricted portion 20 has a substantially constant cross-sectional shape over the entire circumference of the second mounting member 14. In particular, the axial opening portion of the second mounting bracket 14 is a tapered portion 22 that gradually expands toward the opening side, and the depth of the constricted portion 20 is on the upper opening side of the second mounting bracket 14. It becomes gradually shallower as you go. Further, a flange-like portion 24 that extends outward in the radial direction is integrally formed at the opening-side end edge of the constricted portion 20 that is the opening edge on the upper side in the axial direction of the second mounting bracket 14.

  Furthermore, an inclined portion 26 that gradually decreases in diameter as it goes downward in the axial direction is formed in the axially intermediate portion of the second mounting bracket 14, and the large diameter portion 28 is between the inclined portion 26 and the constricted portion 20. On the other hand, the small diameter portion 30 is formed on the lower side in the axial direction than the inclined portion 26. Moreover, the opening edge part by the side of the small diameter part 30 is used as the crimping part bent in the radial direction inner side.

  In the second mounting bracket 14 having such a structure, the first mounting bracket 12 is disposed on substantially the same central axis so as to be spaced apart from the opening portion on the upper side in the axial direction. A main rubber elastic body 16 is disposed between the first mounting bracket 12 and the second mounting bracket 14, and the first mounting bracket 12 and the second mounting bracket are arranged by the main rubber elastic body 16. 14 are elastically connected.

  The main rubber elastic body 16 has a truncated cone shape as a whole, and is vulcanized and bonded to the main rubber elastic body 16 so that the first mounting member 12 is inserted from the end surface on the small diameter side. Further, the opening portion on the upper side in the axial direction of the second mounting bracket 14 is overlapped and vulcanized and bonded to the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16. In particular, in this embodiment, the entire constricted portion 20 is positioned on the outer peripheral surface of the main rubber elastic body 16, and the rubber elastic body integrally formed with the main rubber elastic body 16 is disposed on the outer peripheral side of the constricted portion 20. Filled and fixed. In this embodiment, the main rubber elastic body 16 is an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14.

  Further, the opening of the second mounting bracket 14 is vulcanized and bonded to the outer peripheral surface of the main rubber elastic body 16 in this way, so that the opening on the upper side in the axial direction of the second mounting metal 14 is the main rubber elastic body. 16 is closed fluid-tightly. A mortar-shaped large-diameter recess 32 is formed on the large-diameter side end face of the main rubber elastic body 16 and is opened to the inner peripheral side of the second mounting member 14 in the axially downward direction. .

  Furthermore, a seal rubber layer 34 is formed on the inner peripheral surface of the second mounting bracket 14. The seal rubber layer 34 is integrally formed with the main rubber elastic body 16, and the inner peripheral surfaces of the large diameter portion 28 and the inclined portion 26 are covered over the entire surface by the seal rubber layer 34. The seal rubber layer 34 is slightly thinner than the lower end portion of the main rubber elastic body 16, and the seal rubber layer 34 extends downward from the outer peripheral edge of the lower end portion of the main rubber elastic body 16. At the same time, a step is formed at the opening peripheral edge of the large-diameter recess 32 in the main rubber elastic body 16.

  Further, a diaphragm 36 as a flexible film is assembled to the second mounting member 14 so as to cover the opening portion below the axial direction. The diaphragm 36 is formed of a thin rubber film, has a substantially disk shape with rippled slack, and a cylindrical support fitting 38 is vulcanized and bonded to the outer peripheral edge thereof. Yes. Then, the support fitting 38 is fitted into the lower end portion (small diameter portion 30) of the second attachment fitting 14, and the second attachment fitting 14 is subjected to diameter reduction processing such as eight-way drawing, whereby the diaphragm 36 is formed. It is fixed to the lower end portion in the axial direction of the second mounting bracket 14. Note that the lower end opening of the second mounting bracket 14 is caulked and locked to the lower end of the support bracket 38.

  As the diaphragm 36 is assembled to the second mounting bracket 14 in this manner, the opening on the upper side in the axial direction of the second mounting bracket 14 is fluid-tightly closed by the main rubber elastic body 16 and the second mounting bracket 14 is attached. The opening on the lower side in the axial direction of the metal fitting 14 is fluid-tightly closed by the diaphragm 36. Thereby, on the inner peripheral side of the second mounting bracket 14, a fluid sealed region 40 sealed from the outside is formed between the main rubber elastic body 16 and the diaphragm 36 in the axial direction. The fluid sealing region 40 is filled with an incompressible fluid such as water, alkylene glycol, polyalkylene glycol, or silicone oil. In addition, the fluid is sealed in the fluid sealing region 40 by the diaphragm 36 or the partition member 42 described later with respect to the integrally vulcanized molded product of the main rubber elastic body 16 including the first mounting bracket 12 and the second mounting bracket 14. The assembly can be advantageously done, for example, by performing it in an incompressible fluid.

  A partition member 42 is accommodated in the fluid sealing area 40. The partition member 42 in the present embodiment has a thick disk shape as a whole, and includes a partition member main body 44 and a lid fitting 46.

  The partition member main body 44 is formed of a metal material such as iron or aluminum alloy, a hard synthetic resin material, or the like, and has a thick, substantially disk shape. Further, the partition member main body 44 in the present embodiment is configured to include an upper partition fitting 48 and a lower partition fitting 50.

  The upper partition 48 has a substantially disk shape with a thick and small diameter. In addition, a housing recess 52 is formed at a substantially central portion in the radial direction of the upper partition 48. The housing recess 52 is a shallow circular recess and is formed so as to open upward in the axial direction at a portion slightly deviating from the center of the upper partition fitting 48.

  On the other hand, the lower partition fitting 50 has a thick and large-diameter substantially disk shape. In addition, the outer peripheral edge portion of the lower partition fitting 50 is thicker than the center portion, and the outer peripheral edge portion has a cylindrical shape and protrudes upward in the axial direction. In other words, the central portion of the lower partition metal fitting 50 is recessed in a circular recess shape that opens upward. Further, upper and lower circumferential grooves 54 and 56 extending in a substantially constant cross-sectional shape are formed on the outer peripheral edge of the thick lower partition metal fitting 50 so as to open to the outer peripheral surface and have a predetermined length in the circumferential direction. ing. The upper and lower circumferential grooves 54, 56 are aligned in the circumferential direction at one end in the circumferential direction, and are communicated with each other through a through hole 58. As a result, an outer peripheral groove 60 is formed in the outer peripheral edge of the partition member main body 44 so as to open to the outer peripheral surface and extend by a predetermined length of about one round in the circumferential direction. Furthermore, an inner circumferential concave groove 62 extending in the circumferential direction with a substantially constant cross-sectional shape is formed in a radially intermediate portion of the lower partition metal fitting 50. The inner circumferential concave groove 62 is formed in the central portion of the lower partition metal fitting 50 that is relatively thin, and extends in the circumferential direction by a length of about a half circumference.

  The upper partition metal 48 and the lower partition metal 50 are stacked one above the other to form a partition member main body 44. In the present embodiment, the upper partition metal 48 has a smaller diameter than the lower partition metal 50, and the central portion in the radial direction of the lower partition metal 50 is recessed in a recess shape. The upper partition metal fitting 48 is press-fitted into the recess so that the upper and lower partition metal fittings 48 and 50 are fixedly combined. In the state where the upper partition metal fitting 48 is fitted to the lower partition metal fitting 50, the upper end surface of the upper partition metal fitting 48 is positioned below the upper end surface of the outer peripheral edge of the lower partition metal fitting 50 in the axial direction. . Thereby, the upper end surface of the partition member main body 44 has a concave shape in which the central portion in the radial direction is positioned below the outer peripheral edge in the axial direction.

  Further, under the assembled state of the upper and lower partition fittings 48, 50, the opening of the inner peripheral concave groove 62 formed in the lower partition fitting 50 is closed by the upper partition fitting 48. Thereby, the inner peripheral flow path 64 extending in the circumferential direction inside the partition member main body 44 is formed using the inner peripheral concave groove 62.

  A lid fitting 46 is overlapped and fitted to such a partition member main body 44. The lid fitting 46 has a thin disk shape with a smaller diameter than that of the partition member main body 44, and is formed of a metal material such as iron or aluminum alloy in the present embodiment. The lid metal 46 is superimposed on the upper partition metal 48 from above, and is press-fitted and fixed in a recess in the central portion of the lower partition metal 50. In the present embodiment, a step is provided on the inner peripheral surface of the outer peripheral edge portion of the lower partition fitting 50 that protrudes upward in the shape of a cylinder, and the outer peripheral edge portion of the lid fitting 46 extends from above to the step. It is designed to be superimposed.

  Further, the upper opening of the housing recess 52 is covered by the lid fitting 46 when the lid fitting 46 is assembled to the partition member main body 44. Thereby, the accommodation area | region 66 separated from the exterior using the accommodation recessed part 52 is formed. Further, as shown in FIG. 1, a movable rubber plate 68 as a movable member is accommodated in the accommodation area 66. The movable rubber plate 68 is formed of a rubber elastic body and has a substantially disk shape with a small diameter. Further, the thickness of the movable rubber plate 68 is smaller than the internal dimension of the housing region 66 in the axial direction, and the movable rubber plate 68 is arranged in the housing region 66 so as to be able to be slightly displaced in the mount axis direction, which is the thickness direction. It is installed. In particular, in the present embodiment, the radial dimension of the movable rubber plate 68 is slightly smaller than the internal dimension in the radial direction of the accommodation region 66, and a minute displacement in the axial direction of the movable rubber plate 68 is smoothly realized. It has come to be. Thus, the partition member 42 according to the present embodiment, which includes the partition member main body 44 and the lid fitting 46 and includes the movable rubber plate 68, is configured.

  The partition member 42 having such a movable rubber plate 68 is accommodated and disposed so as to spread in the direction perpendicular to the axis in the fluid sealing region 40 formed between the main rubber elastic body 16 and the diaphragm 36 in the axial direction. It is fitted and fixed to the intermediate portion in the axial direction of the second mounting bracket 14. In particular, in the present embodiment, the partition member 42 is inserted into the second mounting bracket 14, and then subjected to diameter reduction processing such as an eight-way drawing on the second mounting bracket 14, whereby the second mounting bracket 14 14 is fixedly fitted to the base plate. Further, under such an assembled state, the partition member 42 and the support fitting 38 are overlapped with each other in the axial direction, and are provided on the step provided at the lower end portion of the main rubber elastic body 16 and the lower end of the second mounting fitting 14. It is positioned in the axial direction between the caulking portion provided. Furthermore, between the partition member 42 and the second mounting bracket 14, a seal rubber layer 34 formed on the inner peripheral surface of the second mounting bracket 14 is sandwiched and pressed, and the partition member 42 is sealed rubber layer. It is assembled fluid-tightly to the second mounting bracket 14 via 34.

  By arranging the partition member 42 in the fluid sealing region 40 in this way, the fluid sealing region 40 is divided into two in the axial direction by the partition member 42, and one side in the axial direction sandwiching the partition member 42 (see FIG. 1, on the upper side), a part of the wall portion is constituted by the main rubber elastic body 16, and a pressure receiving chamber 70 is formed in which a fluctuation in internal pressure is generated when vibration is input, and the partition member 42 is sandwiched therebetween. On the other side in the axial direction (the lower side in FIG. 1), a balance chamber 72 in which a part of the wall portion is constituted by the diaphragm 36 and volume change is allowed is formed.

  In addition, the outer peripheral surface of the partition member 42 is provided to open to the outer peripheral surface of the partition member 42 by being fluid-tightly superimposed on the inner peripheral surface of the second mounting member 14 via the seal rubber layer 34. The outer opening of the recessed groove 60 is fluid-tightly covered with the second mounting member 14 to form a tunnel-like flow path extending in the circumferential direction. In addition, one end of the tunnel-shaped flow path is communicated with the pressure receiving chamber 70 through a communication hole 74 formed at the upper end of the outer peripheral edge of the lower partition fitting 50, and the other end is connected to the lower partition fitting 50. It communicates with the equilibration chamber 72 through a communication hole 76 formed at the lower end of the outer peripheral edge. As a result, a first orifice passage 78 is formed that extends by a predetermined length in the circumferential direction using the outer circumferential recessed groove 60 and communicates the pressure receiving chamber 70 and the equilibrium chamber 72 with each other.

  Further, the inner peripheral flow path 64 formed in the partition member main body 44 has one end in the circumferential direction communicating with the pressure receiving chamber 70 through a communication hole 80 that extends through the upper partition fitting 48 and the lid fitting 46 in the axial direction. On the other hand, the other end portion in the circumferential direction opens at the upper surface of the lower partition fitting 50 and passes through the communication hole 82 extending radially inward in the partition member main body 44 at the lower center portion of the lower partition fitting 50. It communicates with a recess 84 formed so as to open downward, and communicates with the equilibrium chamber 72 through the recess 84. As a result, a main channel 86 is formed that extends in the circumferential direction by a predetermined length using the inner circumferential channel 64 and communicates the pressure receiving chamber 70 and the equilibrium chamber 72 with each other. In the present embodiment, a groove is formed in the outer peripheral surface of the upper partition fitting 48, and the outer peripheral opening of the groove is covered with the outer peripheral edge of the lower partition fitting 50, and the upper side of the groove A communication hole 80 is formed by communicating the opening with a through hole formed in the lid fitting 46.

  Further, in the present embodiment, the accommodation region 66 provided in the partition member 42 is communicated with the pressure receiving chamber 70 through the through hole 88 formed in the lid fitting 46, and the communication region formed in the upper partition fitting 48. The passage 90 and the communication hole 92 communicate with the intermediate portion in the longitudinal direction of the main flow path 86, and the pressure receiving chamber 70 and the main flow path 86 are mutually connected by the through hole 88, the accommodation region 66, the communication path 90, and the communication hole 92. A branch channel 93 that communicates is configured.

  More specifically, the through-hole 88 is a circular hole having a smaller diameter than the accommodating region 66 and is formed so as to penetrate the lid fitting 46 in the plate thickness direction at a substantially central portion in the radial direction of the lid fitting 46. Under the state where the lid fitting 46 is assembled to the partition member main body 44, the accommodation region 66 is communicated with the opposite region (pressure receiving chamber 70) sandwiching the lid fitting 46 through the through hole 88.

  On the other hand, the communication passage 90 is a tunnel-like flow path formed so as to extend inside the upper partition metal fitting 48, and extends with a circular cross section having a smaller diameter than the accommodation region 66. Further, one end of the communication path 90 is opened in the bottom wall portion of the accommodation region 66 and communicates with the accommodation region 66, and the other end is communicated with the communication hole 92. The communication hole 92 is formed so as to penetrate the upper partition 48 in the thickness direction, the upper opening is closed by the lid metal 46, and the lower opening communicates with the main flow path 86. It communicates with the vicinity of the end on the hole 82 side. As a result, the communication passage 90 is communicated with the main flow path 86 through the communication hole 92, so that the accommodation region 66 and the equilibrium chamber 72 communicate with each other through a part of the communication path 90, the communication hole 92, and the main flow path 86. It has come to be. In the present embodiment, a concave groove is formed in the outer peripheral surface of the upper partitioning metal 48, and the outer peripheral side opening of the concave groove is covered with the outer peripheral edge of the lower partitioning metal 50. A communication hole 92 is formed.

  Thereby, the pressure in the pressure receiving chamber 70 is applied to the upper surface of the movable rubber plate 68 through the through hole 88, and the communication path 90, the communication hole 92, and the main flow path 86 are formed on the lower surface of the movable rubber plate 68. The pressure in the equilibrium chamber 72 is exerted through the section. The hydraulic pressure in the pressure receiving chamber 70 is transmitted to the equilibrium chamber 72 by the displacement of the movable rubber plate 68 in the axial direction, and the pressure receiving chamber 70 and the equilibrium chamber 72 are substantially in communication. .

  In other words, the branch flow path 93 constituted by the through hole 88, the accommodation region 66, and the communication path 90 is provided so as to branch from the intermediate portion in the flow path length direction of the main flow path 86 and communicate with the pressure receiving chamber 70. ing. A part of the branch flow path 93 is formed on the upper surface of the movable rubber plate 68 disposed so as to spread substantially perpendicular to the flow path length direction of the branch flow path 93 on the flow path of the branch flow path 93. The pressure in the pressure receiving chamber 70 is exerted through the through-hole 88, and the equilibration chamber is formed through the communication passage 90, the communication hole 92 and a part of the main flow passage 86 constituting a part of the branch flow path 93 on the lower surface. The pressure in 72 is exerted. Accordingly, the pressure receiving chamber 70 and the equilibrium chamber 72 are substantially in communication with each other through a part of the branch flow path 93 and the main flow path 86 by utilizing a hydraulic pressure transmission action due to the minute displacement of the movable rubber plate 68. The movable rubber plate 68 has a larger diameter than the through hole 88 and the communication path 90, and the outer peripheral portion of the movable rubber plate 68 is brought into contact with the vicinity of the opening of the through hole 88 and the communication path 90. The displacement of the movable rubber plate 68 in the thickness direction is limited.

  As described above, the pressure receiving chamber 70 and the equilibrium chamber 72 are communicated with each other through the main channel 86 and the branch channel 93, and the second orifice channel 94 in the present embodiment is formed by the main channel 86 and the branch channel 93. Is formed. In this embodiment, the flow resistance acting on the fluid that flows between the pressure receiving chamber 70 and the equilibrium chamber 72 through the main channel 86 is the pressure resistance 70 and the equilibrium chamber through the branch channel 93 via the main channel 86. 72 is larger than the flow resistance acting on the fluid flowing between the two. Further, the flow resistance of the main channel 86 and the branch channel 93 can be appropriately set by adjusting the channel cross-sectional area and the channel length of the main channel 86 and the branch channel 93.

  In the present embodiment, the first orifice passage 78 is tuned to a low frequency region around 10 Hz so as to exhibit an effective vibration-proofing effect against the engine shake, while the second orifice passage 94. Is tuned to a medium frequency range of about 20 to 40 Hz so that an effective anti-vibration effect against idling vibration is exhibited. The tuning frequency of the orifice passages 78 and 94 can be set by adjusting the ratio of the passage length and the passage sectional area.

  As described above, the mount main body 95 is configured by assembling the diaphragm 36 and the partition member 42 to the main rubber elastic body 16 provided with the first mounting bracket 12 and the second mounting bracket 14.

  A pneumatic actuator 96 is provided on the side opposite to the equilibrium chamber 72 (on the lower side in the axial direction) across the diaphragm 36. The pneumatic actuator 96 includes a cylindrical bracket 98 and a rubber elastic wall 100.

  The cylindrical bracket 98 is a high-rigidity member formed of a metal material such as iron or aluminum alloy, and has a substantially bottomed cylindrical shape with a deep bottom. Moreover, the opening edge part of the cylindrical bracket 98 is bent toward the outer peripheral side, whereby the contact part 102 extending toward the outer peripheral side is integrally formed over the entire periphery. Further, the cylindrical bracket 98 is provided with an annular stepped portion 104 at the lower end portion in the axial direction, and a large diameter cylindrical portion 106 is formed on the upper side in the axial direction with the stepped portion 104 interposed therebetween. The side is a small diameter cylindrical portion 108. A central protrusion 110 having a substantially inverted cup shape is integrally formed at the center of the bottom wall portion of the cylindrical bracket 98. Furthermore, a port 112 is inserted and fixed to the center protrusion 110 so as to protrude from the center portion outward (downward in the axial direction). An attachment leg 114 is fitted and fixed to the cylindrical bracket 98. The mounting leg portion 114 includes a cylindrical mounting tube portion 116 and a flange-shaped flange portion 118 that extends outward from the lower end edge of the mounting tube portion 116. Furthermore, bolt insertion holes 120 are formed through the flange portion 118 at a plurality of circumferential locations in the axial direction.

  The rubber elastic wall 100 has an annular plate shape as a whole, and its inner peripheral edge is vulcanized and bonded to the opening peripheral edge of the pressing fitting 122 as an output member having a substantially inverted cup shape. The pressing fitting 122 is disposed at a distance from the bottom wall portion of the cylindrical bracket 98 at the center portion in the radial direction of the cylindrical bracket 98. A covering rubber 124 that is integrally formed with the rubber elastic wall 100 is attached to the entire surface of the pressing fitting 122. Further, the outer peripheral edge portion of the rubber elastic wall 100 is vulcanized and bonded to a fitting ring 126 as a substantially annular fitting. The fitting ring 126 is a ring-shaped metal fitting extending in the circumferential direction with a substantially L-shaped cross section having a peripheral wall portion and a bottom wall portion, and the bottom wall portion is embedded and fixed to the outer peripheral edge portion of the rubber elastic wall 100. The outer peripheral surface of the rubber elastic wall 100 is vulcanized and bonded to the inner peripheral surface of the peripheral wall portion.

  Then, the fitting ring 126 to which the outer peripheral edge of the rubber elastic wall 100 is fixed is press-fitted into the small-diameter cylindrical portion 108 of the cylindrical bracket 98, so that the rubber elastic wall 100 provided with the pressing fitting 122 is the cylindrical bracket. 98 is fixed by fitting. Thus, a working air chamber 128 separated from the external space is formed between the opposing surfaces of the pressing fitting 122 and the bottom wall portion of the cylindrical bracket 98. In the present embodiment, the outer peripheral edge portion of the rubber elastic wall 100 is sandwiched between the bottom wall portion of the fitting ring 126 and the bottom wall portion of the cylindrical bracket 98, so that the fitting ring 126 and the cylindrical bracket 98 are inserted. The fluid tightness between the two is ensured.

  A coil spring 129 is accommodated in the working air chamber 128. The coil spring 129 is fitted between the opposed surfaces of the bottom wall portion of the cylindrical bracket 98 and the upper bottom wall portion of the pressing metal member 122 in the center portion in the radial direction, and the pressing metal member 122 is pressed by the biasing force of the coil spring 129. Always energized upward. Note that the coil spring 129 in the present embodiment is positioned on the central protrusion 110 in the bottom wall portion of the cylindrical bracket 98.

  Such a pneumatic actuator 96 is assembled to the mount body 95 by fixing the cylindrical bracket 98 to the second mounting member 14. That is, the large-diameter portion 28 of the second mounting bracket 14 is press-fitted from above in the axial direction with respect to the large-diameter cylindrical portion 106 of the cylindrical bracket 98, and the cylindrical bracket 98 is externally fixed to the second mounting bracket 14. As a result, the pneumatic actuator 96 is assembled to the mount body 95. Particularly in the present embodiment, the abutting portion 102 provided at the upper end portion of the cylindrical bracket 98 is brought into contact with the flange-like portion 24 provided at the upper end portion of the second mounting bracket 14 from below in the axial direction. Thus, the cylindrical bracket 98 is positioned relative to the second mounting member 14 in the axial direction.

  In addition, when the cylindrical bracket 98 is fitted to the second mounting bracket 14, the upper bottom portion of the pressing bracket 122 of the pneumatic actuator 96 is disposed to face the center of the bottom portion of the partition member 42 with the diaphragm 36 interposed therebetween. Has been. In this state, when the working air chamber 128 is connected to the atmosphere, the pressing fitting 122 is elastically projected upward by the urging force of the coil spring 129 as shown in FIG. The diaphragm 36 is pressed against the opening of the recess 84 by the upper bottom portion of the pressing fitting 122.

  In such an engine mount 10, the first mounting bracket 12 is fixed to a mounting bracket (not shown) with mounting bolts 18 and the mounting bracket is also attached to the power unit side of an automobile (not shown). The mounting bracket 12 is attached to the power unit side of the automobile. On the other hand, a fixing bolt (not shown) is inserted into a bolt insertion hole 120 formed in the mounting leg portion 114 of the cylindrical bracket 98 that is externally fitted and fixed to the second mounting bracket 14, and the fixing bolt is a sub-mount in the automobile. The second mounting bracket 14 is attached to the vehicle body side via the cylindrical bracket 98 by being screwed to a vehicle body side (not shown) such as a frame. As a result, the engine mount 10 is interposed between the power unit of the automobile which is one member to be vibration-proof connected and the body of the car which is the other member to be vibration-proof connected, and the power unit is vibration-proof with respect to the vehicle body. It comes to support.

  Note that, when the engine mount 10 is mounted on a vehicle, the shared support load of the power unit is exerted between the first mounting bracket 12 and the second mounting bracket 14 in a substantially axial direction, so that the main body The rubber elastic body 16 is elastically deformed by a predetermined amount, and the first mounting bracket 12 and the second mounting bracket 14 are displaced by a predetermined amount in the approaching direction in the axial direction.

  As a result, the diaphragm 36 is held at a position separated from the lower surface of the partition member 42 in a state where no external force is exerted. However, in a state where the atmospheric pressure is exerted on the working air chamber 128, the pressing fitting 122 is elastically projected upward based on the urging force of the coil spring 129, and the diaphragm 36 is pressed against the opening of the recess 84 by the upper bottom portion of the pressing fitting 122, The second orifice passage 94 is maintained in the shut-off state.

  Further, when the engine mount 10 is mounted on the vehicle, the air pipe 130 is connected to the port 112 attached to the bottom wall portion of the cylindrical bracket 98 constituting the pneumatic actuator 96, and the air The working air chamber 128 is selectively connected to the atmosphere and the negative pressure source 132 through the pipe line 130. That is, a switching valve 134 is disposed on the air pipe line 130 connected to the working air chamber 128, and the switching valve 134 is controlled by the control device 136 to be switched. The working air chamber 128 is selectively switched and connected to the atmosphere and the negative pressure source 132.

  When a negative pressure is applied to the working air chamber 128 of the pneumatic actuator 96 from the outside, the pressing fitting 122 is attracted to the working air chamber 128 side and displaced downward against the urging force of the coil spring 129. It is done. As a result, the pressing force to the diaphragm 36 based on the urging force of the coil spring 129 is released, and the second orifice passage 94 is maintained in a communicating state. A buffer stopper rubber 138 that protrudes downward is formed on the upper bottom portion of the press fitting 122, and the displacement amount of the press fitting 122 when the press fitting 122 is pulled down by negative pressure suction is determined by the port of the buffer stopper rubber 138. The contact with 112 is limited in a buffering manner.

  As described above, in the engine mount 10 according to the present embodiment, the atmospheric pressure and the negative pressure are selectively exerted on the working air chamber 128, whereby the second orifice passage 94 is controlled to be communicated / blocked to switch the vibration isolation characteristics. It can be changed. In particular, in the present embodiment, the atmospheric pressure and the negative pressure exerted on the working air chamber 128 are selectively controlled according to the traveling state of the automobile.

  In other words, in the present embodiment, when the vehicle is in a driving state where vibration in the low frequency region such as engine shake is a major problem, the atmospheric pressure is applied to the working air chamber 128 as shown in the model diagram of FIG. As a result, the diaphragm 36 is pressed by the pneumatic actuator 96, and the diaphragm 36 is pressed against the opening of the second orifice passage 94 to the equilibrium chamber 72, thereby blocking the second orifice passage 94. Thereby, when vibration in a low frequency range is input, the fluid between the pressure receiving chamber 70 and the equilibrium chamber 72 through the first orifice passage 78 in the direction indicated by the white arrow in FIG. The flow is effectively generated. Therefore, based on the fluid action such as the resonance action of the fluid that flows between the two chambers 70 and 72 through the first orifice passage 78, the target vibration-proof effect is effectively exhibited.

  Further, in the present embodiment, when the automobile is running, the opening of the second orifice passage 94 on the equilibrium chamber 72 side is controlled to be closed by the pneumatic actuator 96. Therefore, the fluid flow is generated between the pressure receiving chamber 70 and the equilibrium chamber 72 through the second orifice passage 94 which is tuned to a high frequency region and has a small flow resistance as compared with the first orifice passage 78. By preventing the fluid flow through the first orifice passage 78, it is possible to effectively obtain the vibration isolation effect exhibited by providing the first orifice passage 78 tuned in the low frequency range. .

  Further, in the present embodiment, when the automobile is stopped, which causes vibration in the middle to high frequency range such as idling vibration, a negative pressure is applied to the working air chamber 128 as shown in the model diagram of FIG. Thus, the restriction of the diaphragm 36 by the pneumatic actuator 96 is released, and the diaphragm 36 is separated from the opening portion of the second orifice passage 94 toward the equilibrium chamber 72 side, whereby the second orifice passage 94 is brought into a communication state. To do. Thereby, when vibration in the middle frequency range is input, the fluid passing through the second orifice passage 94 between the pressure receiving chamber 70 and the equilibrium chamber 72 in the direction indicated by the white arrow in FIG. The flow is generated, and the vibration isolation effect based on the fluid flow action is exhibited in the middle frequency range that is the tuning frequency of the second orifice passage 94.

  In addition, when vibration in a high frequency range is input, the fluid flow through the main flow path 86 tuned to a lower frequency range than the input vibration decreases, and is indicated by a white arrow in FIG. In the direction, the hydraulic pressure absorbing action due to the minute displacement of the movable rubber plate 68 is positively exerted along with the resonance of the movable rubber plate 68. As a result, an effective anti-vibration effect is exhibited even when inputting vibration in a high frequency range. In the present embodiment, the first orifice passage 78 tuned to a lower frequency range than the input vibration is substantially clogged by an anti-resonant action when a vibration is input in the middle to high frequency range. Therefore, the escape of the hydraulic pressure through the first orifice passage 78 that is always in a communication state has little influence on the anti-vibration performance against vibrations in the middle to high frequency range.

  As described above, in the automobile engine mount 10 having the structure according to the present embodiment, the vibration-proofing effect based on the fluid action of the fluid that is caused to flow through the first and second orifice passages 78 and 94, and the small amount of the movable rubber plate 68 are obtained. All of the vibration isolation effects based on the hydraulic pressure absorbing action due to the displacement can be effectively obtained, and the excellent vibration isolation effects are exhibited against a plurality of vibrations in a wide frequency range. In particular, when an anti-vibration effect based on the fluid action of the fluid that is caused to flow through the first and second orifice passages 78 and 94 is required, these orifice passages are caused by the fluid pressure absorption action due to the minute displacement of the movable rubber plate 68. It is possible to prevent the amount of fluid flow through 78 and 94 from being reduced, and to effectively exhibit the intended vibration-proofing effect.

  Further, in the present embodiment, the branch flow path 93 provided with the movable rubber plate 68 exhibiting the anti-vibration effect against the vibration in the high frequency region is provided in the middle portion of the main flow path 86 constituting the second orifice passage 94. Similarly to the second orifice passage 94 that exhibits a vibration-proofing effect against vibrations in the middle frequency range, it communicates with the equilibrium chamber 72 through the recess 84. Therefore, when the vibration is input in the low frequency range, as shown in FIG. 2, the diaphragm 36 is pressed against the partition member 42 by the pneumatic actuator 96 to close the recess 84, thereby It is possible to simultaneously block the second orifice passage 94, which is a vibration isolation device, and restrain the movable rubber plate 68, which is a vibration isolation device in a high frequency range, with simple control. Thereby, the fluid flow through the first orifice passage 78 which is a vibration isolating device in a low frequency range can be advantageously caused, and the vibration isolating effect based on the fluid flow action can be effectively exhibited.

  As mentioned above, although one Embodiment of this invention has been described, this is an illustration to the last, Comprising: This invention is not limited at all by the specific description in this Embodiment.

  For example, in the engine mount 10 shown in the above embodiment, the partition member 42 includes the upper and lower partition fittings 48 and 50 and the lid fitting 46, but the partition member 42 is not necessarily combined with these members. It does not have to be configured. In the above embodiment, the upper and lower partition fittings 48 and 50 and the lid fitting 46 constituting the partition member 42 are formed of a metal material. However, for example, the partition member 42 may be formed of a hard synthetic resin material or the like. .

  In addition, the specific structure of the second orifice passage 94 shown in the above embodiment is merely an example, and the shape and branch position of each flow path of the main flow path 86 and the branch flow path 93 are required. It is designed appropriately according to vibration characteristics and the like.

  In the above embodiment, an example in which the movable rubber plate 68 disposed so as to be minutely displaceable in the flow path length direction of the branch flow path 93 is adopted as the movable member. The movable member can also be configured by a movable rubber film in which the outer peripheral surface of the rubber elastic body is fixed to the inner peripheral wall surface of the accommodation region 66. According to this, a minute displacement in the flow path length direction of the branch flow path 93 is realized by elastic deformation of the movable rubber film, and the same hydraulic pressure absorption effect as that of the above embodiment is effectively exhibited. obtain.

  In the above-described embodiment, the pneumatic actuator 96 is shown as an example of an actuator that switches the second orifice passage 94 between the communication state and the cutoff state. For example, the actuator is an electromagnetic actuator that is driven by energization control. Various known actuators can be used.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

The longitudinal cross-sectional view which shows the engine mount for motor vehicles as one Embodiment of this invention. Explanatory drawing which shows the engine mount shown in FIG. 1 at the time of the vibration input of a low frequency range as a schematic model figure. Explanatory drawing which shows the engine mount shown in FIG. 1 at the time of the vibration input of a middle frequency range as a schematic model figure. Explanatory drawing which shows the engine mount shown in FIG. 1 at the time of the vibration input of a high frequency area as a schematic model figure.

Explanation of symbols

10: Engine mount for automobile, 12: First mounting bracket, 14: Second mounting bracket, 16: Rubber elastic body, 36: Diaphragm, 42: Partition member, 66: Storage area, 68: Movable rubber plate, 70: pressure receiving chamber, 72: equilibrium chamber, 78: first orifice passage, 86: main passage, 93: branch passage, 94: second orifice passage, 96: pneumatic actuator

Claims (3)

The first mounting member is spaced apart from one opening side of the second mounting member having a cylindrical portion, and the first mounting member and the second mounting member are connected by the main rubber elastic body. The partition member is supported by the second mounting member, and a pressure receiving chamber in which a part of the wall portion is formed of the main rubber elastic body is formed on one side sandwiching the partition member, and the partition member On the other side of the wall, an equilibrium chamber whose part of the wall portion is made of a flexible film is formed, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber. A first orifice passage communicating the chambers with each other and a second orifice passage tuned in a higher frequency range than the first orifice passage, while being opposite to the equilibrium chamber with the flexible membrane interposed therebetween An actuator is disposed on the side, and the second orifice is utilized using the actuator. In the fluid filled type vibration damping device and capable of switching offices passage cutoff state to the communicating state,
Forming a recess in a central portion of the end face on the equilibrium chamber side of the partition member;
A communication hole extending from the inner peripheral surface of the recess toward the outer peripheral side of the partition member, and a communication path extending from the communication hole in the thickness direction of the partition member and opening to an end surface of the partition member on the pressure receiving chamber side the pressure receiving chamber and said equilibrium chamber cross to form a main flow path communicating with, and form a branch flow passage communicating with the receiving chamber branches at an intermediate portion of the communication passage in the main flow path by the, the While constituting the second orifice passage including the main flow path and the branch flow path ,
A movable member capable of minute displacement is disposed on the flow path of the branch flow path so that the pressure in the pressure receiving chamber can be applied to one surface of the movable member through the branch flow path, and the other as the pressure of the equilibrium chamber is caused to act through said main passage and said branch passage to the surface, further,
By pressing the flexible film against the opening of the recess of the partition member by the actuator, the main flow path and the divided flow path that constitute the second orifice passage are simultaneously blocked. A fluid-filled vibration isolator characterized by being configured as described above .
  The flow resistance exerted on the fluid flowing between the pressure receiving chamber and the equilibrium chamber through the main flow path is greater than the flow resistance exerted on the fluid flowed between the pressure receiving chamber and the equilibrium chamber through the branch flow path. The fluid-filled vibration isolator according to claim 1, which is larger.   The movable member is a movable rubber plate formed of a rubber elastic body, and the movable rubber plate is disposed so as to spread perpendicularly to the flow path direction of the branch flow path. The fluid-filled vibration isolator according to claim 1 or 2, wherein a minute displacement in a direction is allowed.

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