JP6604825B2 - Liquid-filled vibration isolator - Google Patents

Description

  The present invention relates to a liquid-filled vibration isolator, and more particularly to a liquid-filled vibration isolator that can suppress the generation of abnormal noise.

  2. Description of the Related Art Conventionally, a diaphragm that forms a liquid chamber in which liquid is sealed between a vibration isolating base and a vibration isolating base that is attached to the second mounting tool and connects the first mounting tool and the cylindrical second mounting tool. A liquid enclosure type anti-vibration device comprising: a partition that divides the liquid chamber into a first liquid chamber on the vibration-isolating base side and a second liquid chamber on the diaphragm side; and an orifice that communicates the first liquid chamber and the second liquid chamber. Shaking devices are known. In this type of liquid-filled vibration isolator, the partition body is an annular orifice forming member that forms an orifice, and a rubber-like member that is vulcanized and bonded to the orifice forming member and closes the inside of the inner peripheral surface of the orifice forming member. Some include an elastic wall and a pair of partition plates that are connected to each other via a connecting portion that penetrates the elastic wall to sandwich the elastic wall from both sides in the axial direction (Patent Document 1).

  In the technique disclosed in Patent Document 1, one partition plate (first partition plate) facing the first liquid chamber has a smaller outer shape than the other partition plate (second partition plate) facing the second liquid chamber. Is formed. Thereby, since the displacement restriction effect of the elastic wall can be suppressed by the first partition plate at the time of pressurizing displacement (compression input) of the first liquid chamber, it is possible to prevent the first liquid chamber from being excessively pressurized. On the other hand, at the time of negative pressure displacement (tensile input) of the first liquid chamber, the displacement of the elastic wall is regulated by the second partition plate, and a high damping coefficient can be obtained by utilizing the resonance phenomenon of the liquid flowing through the orifice. .

JP 2007-211972 A

  However, in the conventional technique described above, the displacement of the elastic wall is restricted by the second partition plate when the first liquid chamber is displaced by negative pressure (compression input), so that the first liquid chamber is in an excessively negative pressure state and pressure is increased. If the water vapor pressure is lower than the saturated water vapor pressure of the liquid, there is a problem that an impact sound (abnormal noise) is generated when the generated bubbles disappear.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a liquid-filled vibration isolator that can suppress the generation of abnormal noise when the first liquid chamber is displaced by negative pressure.

Means for Solving the Problems and Effects of the Invention

In order to achieve this object, according to the liquid-filled vibration isolator of claim 1, the first fixture and the cylindrical second fixture are connected by a vibration isolating base made of a rubber-like elastic body. The A diaphragm made of a rubber-like elastic body is attached to the second fixture, and a liquid chamber in which a liquid is sealed is formed between the vibration-proof base. The partition chamber partitions the liquid chamber into a first liquid chamber on the vibration-proof base side and a second liquid chamber on the diaphragm side. In the partition, an annular orifice forming member that forms an orifice that communicates between the second liquid chamber and the first liquid chamber is disposed inside the second fixture. The periphery of the elastic wall composed of the rubber-like elastic body is bonded to the orifice forming member, and the first partition plate facing the first liquid chamber and the second partition plate facing the second liquid chamber are located at the center of the elastic wall. They are connected to each other through a connecting part that penetrates. The first partition plate is in contact with the elastic wall when the first contact portion located around the connection portion is unloaded, and the second partition plate is the elastic wall when the second contact portion located around the connection portion is unloaded. To touch. Since the size of the outer edge of the projection surface projected in the axial direction is set to be smaller than the outer edge of the projection surface of the first contact portion projected in the axial direction, the second contact portion is at the time of negative pressure displacement of the first liquid chamber. The displacement regulating effect of the elastic wall can be suppressed by the second partition plate. Since the displacement of the elastic wall can suppress the first liquid chamber from being brought into an excessive negative pressure state, there is an effect of suppressing the generation of abnormal noise when the first liquid chamber is displaced by negative pressure.

  According to the liquid-filled vibration isolator of claim 2, the second partition plate has a peripheral portion located around the second contact portion connected to the second contact portion. Since the peripheral portion is arranged at a distance in the axial direction from the elastic wall, the deformation of the elastic wall is not restricted by the peripheral portion when the deformation amount of the elastic wall at the time of negative pressure displacement of the first liquid chamber is small. When the amount of deformation of the elastic wall increases and the elastic wall and the peripheral part interfere with each other, the deformation of the elastic wall is restricted. Since excessive deformation of the elastic wall can be suppressed by the peripheral portion, in addition to the effect of the first aspect, there is an effect of ensuring the durability of the elastic wall.

It is an axial sectional view of the liquid filled type vibration isolator in the first embodiment of the present invention. It is an exploded three-dimensional view of the partition seen from the 1st partition plate side. It is an exploded three-dimensional view of the partition seen from the 2nd partition plate side. It is an axial sectional view of a partition. It is an axial sectional view of the partition of the liquid filled type vibration isolator in the second embodiment. It is an exploded three-dimensional view of a partition. It is an axial sectional view of the partition of the liquid filled type vibration isolator in the third embodiment. It is an exploded three-dimensional view of a partition.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, the structure of the liquid filled type vibration isolator 10 will be described with reference to FIG. FIG. 1 is an axial sectional view of a liquid filled type vibration damping device 10 according to a first embodiment of the present invention. FIG. 1 illustrates a state before the engine is supported (that is, a no-load state before the weight of the engine is loaded).

  The liquid-filled vibration isolator 10 is a vibration isolator for supporting and fixing an automobile engine (vibrating body, not shown) while preventing the vibration of the engine from being transmitted to a vehicle body frame (not shown). 1. As shown in FIG. 1, a first fixture 11 attached to the engine side, a cylindrical second fixture 13 attached to the vehicle body frame side below the engine, and a rubber-like elastic body connecting these components. A liquid chamber (a first liquid chamber 23 and a second liquid chamber 24) is formed between the vibration-proof base 17 and the vibration-proof base 17 attached to the second fixture 13, and from a rubber-like elastic body. A diaphragm 20 is provided.

  The first fixture 11 is a member formed in a substantially cylindrical shape from a metal material such as an aluminum alloy, and a screw hole 12 into which a bolt is screwed is formed on an upper end surface thereof. The first fixture 11 is attached to the engine side via a bolt screwed into the screw hole 12. The second fixture 13 includes a cylindrical metal fitting 14 on which a vibration-proof base 17 is vulcanized and a bottom metal fitting 15 fixed below the cylindrical metal fitting 14 by caulking. The cylindrical metal fitting 14 is formed in a cylindrical shape having an opening extending upward, and the bottom metal fitting 15 is formed in a cup shape having a bottom portion, respectively, from a steel material or the like. A bolt 16 projects downward from the bottom of the bottom metal fitting 15. The second fixture 13 is attached to the vehicle body via the bolt 16.

  The anti-vibration base 17 is a member formed in a truncated cone shape from a rubber-like elastic body, and is vulcanized and bonded between the lower surface side of the first fixture 11 and the upper end opening of the cylindrical fitting 14. Rubber films 18 and 19 covering the inner peripheral surface of the cylindrical metal fitting 14 are connected to the lower end portion of the vibration isolating base 17. The rubber film 19 is formed in a step shape in which the inner diameter is larger than the inner diameter of the rubber film 18.

  The diaphragm 20 is formed as a rubber film bent in a bellows shape from a rubber-like elastic body, and the outer periphery is vulcanized and bonded to an annular mounting plate 21 as viewed from above. The diaphragm 20 is attached to the second fixture 13 by the mounting plate 21 being clamped and fixed together with the bottom fitting 15 by the cylindrical fitting 14. As a result, a liquid chamber is formed between the upper surface side of the diaphragm 20 and the lower surface side of the vibration isolating substrate 17. An antifreeze liquid (not shown) such as ethylene glycol is sealed in the liquid chamber.

  The partition 30 is a member for partitioning the liquid chamber into a first liquid chamber 23 on the vibration isolating base 17 side and a second liquid chamber 24 on the diaphragm 20 side, and between the vibration isolating base 17 and the diaphragm 20. Arranged. The partition 30 includes an annular orifice forming member 31 disposed inside the second fixture 13, an elastic wall 50 that covers a portion surrounded by the inner peripheral surface 40 of the orifice forming member 31, and the elastic wall 50 as an axis. A first partition plate 60 and a second partition plate 70 sandwiched from both sides in the direction are provided.

  The partition 30 will be described with reference to FIGS. 2 is an exploded three-dimensional view of the partition body 30 viewed from the first partition plate 60 side, FIG. 3 is an exploded view of the partition body 30 viewed from the second partition plate 70 side, and FIG. FIG.

  As shown in FIGS. 2 and 3, the orifice forming member 31 constituting the outline of the partition body 30 is provided with an orifice 25 (FIG. 1) extending in the circumferential direction between the inner peripheral surface (rubber film 19) of the second fixture 13. A ring-shaped wall portion 32 that is disposed orthogonal to the axis O, and that is connected to the inner periphery of the wall portion 32 and that is in the direction of the axis O (axis A cylindrical body portion 34 extending in the direction), and a wall portion 35 projecting radially outward from the lower end portion of the body portion 34 in a flange shape.

  The orifice forming member 31 is formed with a notch 33 and an opening 36 in the walls 32 and 35, respectively. Since the vertical wall 37 that connects the wall portions 32 and 35 and the body portion 34 and separates the notch 33 and the opening 36 is provided in the orifice forming member 31, the orifice 25 (see FIG. 1) is circumferentially moved by the vertical wall 37. And is communicated with the first liquid chamber 23 through the notch 33 and with the second liquid chamber 24 through the opening 36. That is, the orifice forming member 31 forms the orifice 25 having a flow path length of about one round from the notch 33 to the opening 36. The orifice forming member 31 includes an annular extending portion 38 that extends to the opposite side of the body portion 34 across the wall portion 32 in the axial direction, and an extension that is opposite to the wall portion 32 across the extending portion 38. An annular convex portion 39 protruding inward in the radial direction of the portion 38 is provided.

  As shown in FIG. 4, the elastic wall 50 is a member made of a rubber-like elastic body, and the outer peripheral surface is vulcanized and bonded to the extended portion 38 of the orifice forming member 31 and the inner peripheral surface 40 of the convex portion 39. Yes. The elastic wall 50 is a film-like member that is vulcanized and bonded to the orifice forming member 31, and the wall surfaces 51 and 52 face the first liquid chamber 23 and the second liquid chamber 24, respectively. The elastic wall 50 is formed with a circular central hole 53 that penetrates the center in the radial direction in the thickness direction (axial center O direction). It is provided around. The elastic wall 50 is set such that the axial thickness near the orifice forming member 31 is larger than the axial thickness near the ridge 54 (distance between the wall surfaces 51 and 52), and the axial direction O extends from the extending portion 38. An annular raised portion 55 that protrudes toward the top is provided.

  The elastic wall 50 has a concave portion 56 that is recessed in the axial direction on the wall surface 52 facing the second liquid chamber 24 among the wall surfaces 51, 52 formed in a curved surface. A plurality of recesses 56 (four in the present embodiment) are provided at regular intervals in the circumferential direction of the elastic wall 50. The concave portion 56 is formed in a substantially fan shape when viewed in the axial direction, and is a line segment connecting the axis O passing through the center of the elastic wall 50 (center of the central hole 53) and the inner peripheral surface 40 of the orifice forming member 31. It is provided on the outer peripheral side from the point.

  Returning to FIG. The first partition plate 60 and the second partition plate 70 are substantially circular members whose outer shape is set smaller than the outer shape of the elastic wall 50 (the size of the inner peripheral surface 40 of the orifice forming member 31) when viewed in the axial direction. . The center part 61 and the outer peripheral part 64 of the first partition plate 60 are integrally formed of a thermoplastic resin, and the center part 71 of the second partition plate 70 is formed of a thermoplastic resin. The central portions 61 and 71 are respectively formed with annular grooves 62 and 72 into which both axial sides of the protrusion 54 of the elastic wall 50 are fitted.

  The second partition plate 70 is provided with a connecting portion 73 protruding in the axial direction at the center of the central portion 71, and the first partition plate 60 is fitted with the connecting portion 73 at the center of the central portion 61. A fitting recess 63 is formed. The first partition plate 60 and the second partition plate 70 are connected by fixing the connecting portion 73 by ultrasonic welding in a state in which the connection portion 73 is fitted in the fitting recess 63, and the elastic wall 50 is connected to the first partition plate 60 and the first partition plate 60. The two partition plates 70 are sandwiched from both sides in the axial direction.

  The first partition plate 60 is curved so that the outer peripheral portion 64 has a radially inner surface in close contact with the wall surface 51 of the elastic wall 50 and a radially outer surface away from the wall surface 51. As for the 1st partition plate 60, the whole center part 61 and a part of radial direction inner side of the outer peripheral part 64 contact the wall surface 51 of the elastic wall 50 in a no-load state (state before load of an engine weight). The first contact portion 65 is configured. The 2nd partition plate 70 comprises the 2nd contact part 74 where the whole center part 71 contacts the wall surface 52 of the elastic wall 50 in a no-load state. The size of the projection surface projected in the axial direction of the second contact portion 74 is set smaller than that of the first contact portion 65 projected in the axial direction. In the first partition plate 60, the outer edge of the first contact portion 65 is positioned radially inward from the recess 56 (the outer edge of the recess 56) formed in the elastic wall 50.

  Next, a manufacturing method of the liquid filled type vibration isolator 10 (see FIG. 1) will be described. First, a first molded body in which the first fixture 11 and the cylindrical metal fitting 14 are connected by a vibration-isolating base 17, and a second molded body in which the diaphragm 20 is vulcanized and the mounting plate 21 is vulcanized and bonded. Are each vulcanized and molded by a rubber vulcanization mold. Separately, the elastic wall 50 is vulcanized by a rubber vulcanization mold, and the elastic wall 50 is bonded to the orifice forming member 31. The partition 30 is manufactured by sandwiching the first partition plate 60 and the second partition plate 70 from both the front and back sides of the elastic wall 50 and fixing the connecting portion 73 by ultrasonic welding.

  In the liquid, the partition 30 is inserted into the cylindrical fitting 14 from the first partition plate 60 side through the lower opening of the first molded body, and then the second molded body is inserted into the cylindrical fitting 14. The cylindrical metal fitting 14 is reduced in diameter, and the partition body 30 and the diaphragm 20 are attached to the cylindrical metal fitting 14. Thereafter, in a posture in which the first fixture 11 is in a downward position, this member is taken out of the liquid, and the bottom fitting 15 is put on while maintaining this posture, and the bottom fitting 15 is fixed to the lower opening of the cylindrical fitting 14 by caulking. To do. Thereby, the manufacture of the liquid filled type vibration isolator 10 is completed.

  Next, the operation of the liquid filled type vibration isolator 10 will be described. When a small amplitude vibration in a high frequency range is input to the liquid-filled vibration isolator 10, the first partition plate 60 and the second partition plate 70 are reciprocated together so that the first liquid chamber 23 Vibration can be reduced by absorbing hydraulic pressure.

  On the other hand, when a large amplitude vibration in a low frequency range is input to the liquid-filled vibration isolator 10, the first partition plate 60 is used when the first liquid chamber 23 is displaced under pressure (compression input of the vibration isolator base 17). Since the displacement of the elastic wall 50 is regulated by (especially the first contact portion 65), a high attenuation coefficient can be obtained by utilizing the resonance phenomenon of the liquid flowing through the orifice 25. At the time of negative pressure displacement of the first liquid chamber 23 (tensile input of the vibration isolator base 17), the effect of restricting the displacement of the elastic wall 50 by the second partition plate 70 is poor, so the elastic wall 50 is placed on the first liquid chamber 23 side. It can be easily bent and deformed. Since the first liquid chamber 23 is prevented from being rapidly depressurized by the deformation of the elastic wall 50, it is possible to prevent cavitation from occurring in the first liquid chamber 23, and it is possible to suppress the generation of impact sound (abnormal noise).

  Since the orifice forming member 31 is provided with a convex portion 39 protruding radially inward, the rigidity of the base portion (outer peripheral portion) of the elastic wall 50 is increased, and the elastic wall at the time of low frequency and large amplitude The effect of regulating 50 displacements can be improved. Further, the raised portion 55 also has an effect of increasing the rigidity of the base portion of the elastic wall 50.

  Since the thickness of the elastic wall 50 can be partially reduced by forming the recess 56 in the wall surface 52, the elastic wall 50 can be easily bent and deformed, and the spring of the elastic wall 50 can be softened. The first partition plate 60 attached to the elastic wall 50 suppresses the function of the first contact portion 65 limiting the deformation of the elastic wall 50 because the outer edge of the first contact portion 65 is positioned radially inward from the recess 56. it can. Therefore, the spring of the elastic wall 50 can be softened by the recess 56.

  Since the elastic wall 50 has the protrusion 54 formed at the center, the rigidity of the center of the elastic wall 50 can be secured. Since the second partition plate 70 having the central portion 71 attached to the high-rigid protrusion 54 is connected to the first partition plate 60, the first partition plate 60 can be prevented from unstablely swaying on the wall surface 51. . As a result, the stable vibration reduction effect by the liquid filled type vibration isolator 10 can be ensured.

  Next, a second embodiment will be described with reference to FIGS. In 1st Embodiment, the case where the 2nd partition plate 70 did not have an outer peripheral part was demonstrated. On the other hand, 2nd Embodiment demonstrates the case where the 2nd partition plate 90 has the outer peripheral part 91. FIG. In addition, about the part same as the part demonstrated in 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 5 is a sectional view in the axial direction of the partition 80 of the liquid filled type vibration isolator according to the second embodiment, and FIG. 6 is an exploded view of the partition 80. The partition 80 is mounted in place of the partition 30 of the liquid-filled vibration isolator 10 described in the first embodiment. The partition 80 includes an orifice forming member 31, an elastic wall 50 vulcanized and bonded to the orifice forming member 31, and a first partition plate 60 and a second partition plate 90 that sandwich the elastic wall 50 from both sides in the axial direction. ing.

  The second partition plate 90 is a substantially circular member whose outer shape is set smaller than the outer shape of the elastic wall 50 (the size of the inner peripheral surface 40 of the orifice forming member 31) when viewed in the axial direction. As for the 2nd partition plate 90, the center part 71 and the outer peripheral part 91 are integrally shape | molded with the thermoplastic resin. As for the 2nd partition plate 90, the outer peripheral part 91 is formed in the disk shape which the whole surface (except for the recessed part 56) closely_contact | adheres to the wall surface 52 of the outer side of the protrusion 54 of the elastic wall 50. FIG. The second partition plate 90 constitutes a second contact portion 92 in which the entire central portion 71 and the outer peripheral portion 91 are in contact with the wall surface 52 of the elastic wall 50 in a no-load state (a state before the weight of the engine is loaded). To do. In the second contact portion 92, the size of the projection surface projected in the axial direction is set smaller than the projection surface of the first contact portion 65 projected in the axial direction. In the second partition plate 90, the outer edge of the second contact portion 92 is positioned closer to the center side (the connecting portion 73 side) than the radially outer edge of the recess 56 formed in the elastic wall 50.

  According to the second embodiment, when a small amplitude vibration in a high frequency range is input, the first liquid chamber 23 is reciprocally moved together by the first partition plate 60 and the second partition plate 90. The vibration can be reduced by absorbing the hydraulic pressure. On the other hand, when large-amplitude vibration in a low frequency range is input, the first partition plate 60 (particularly the first contact portion 65) is used when the first liquid chamber 23 is displaced under pressure (compression input of the vibration-isolating base 17). Therefore, the displacement of the elastic wall 50 is restricted, so that a high damping coefficient can be obtained by the orifice 25. At the time of negative pressure displacement of the first liquid chamber 23 (tensile input of the vibration isolation base 17), the effect of regulating the displacement of the elastic wall 50 by the second partition plate 90 is less than that of the first partition plate 60. 50 can be easily bent and deformed toward the first liquid chamber 23. Due to the deformation of the elastic wall 50, rapid decompression of the first liquid chamber 23 can be prevented, and cavitation can hardly occur in the first liquid chamber 23. Since the second contact portion 92 is in contact with the wall surface 52 around the ridge 54, the amount of deformation of the elastic wall 50 toward the first liquid chamber 23 can be limited. Therefore, both suppression of cavitation and securing of the durability of the elastic wall 50 can be achieved.

  Since the recesses 56 are intermittently provided in the circumferential direction of the wall surface 52 of the elastic wall 50, a portion between the adjacent recesses 56 (a portion that is not depressed) is during the second partition plate 90 vibrates in the axial direction. Also, the state in contact with the second partition plate 90 (second contact portion 92) can be maintained. Therefore, abnormal noise caused by interference (blow) between the elastic wall 50 and the second partition plate 90 can be suppressed.

  In the second partition plate 90 attached to the elastic wall 50, the outer edge of the second contact portion 92 is positioned radially inward from the concave portion 56 (edge on the outer side in the radial direction). The function of limiting deformation can be suppressed. Therefore, the spring of the elastic wall 50 can be softened by the recess 56.

  The concave portion 56 formed in the elastic wall 50 is such that the radially outer edge (wall surface 52) is in close contact with the second partition plate 90 in a neutral position (no load state) where no load is applied to the elastic wall 50. Instead, a gap is secured between the second partition plate 90 and the second partition plate 90. The gap can have a function as a high-frequency orifice that operates in a higher frequency range than the orifice 25. In this portion, liquid resonance in a specific frequency band is generated, and the dynamic spring constant of the frequency band can be reduced. The characteristics can be tuned by changing the number and size of the recesses 56 and the size and length of the gap.

  Next, a third embodiment will be described with reference to FIGS. In 2nd Embodiment, the case where the 2nd partition plate 90 contact | adhered to the elastic wall 50 (except for the recessed part 56) was demonstrated in the no-load state. On the other hand, 3rd Embodiment demonstrates the case where the radial direction outer side of the 2nd partition plate 100 spaces apart with the elastic wall 50. FIG. In addition, about the part same as the part demonstrated in 1st and 2nd embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 7 is an axial sectional view of the partition 81 of the liquid filled type vibration isolator according to the third embodiment, and FIG. 8 is an exploded view of the partition 81. The partition 81 is mounted in place of the partition 30 of the liquid-filled vibration isolator 10 described in the first embodiment. The partition 81 includes an orifice forming member 31, an elastic wall 50 vulcanized and bonded to the orifice forming member 31, and a first partition plate 60 and a second partition plate 100 that sandwich the elastic wall 50 from both sides in the axial direction. ing.

  The second partition plate 100 is a substantially bowl-shaped member whose outer shape is set smaller than the outer shape of the elastic wall 50 (the size of the inner peripheral surface 40 of the orifice forming member 31) when viewed in the axial direction. As for the 2nd partition plate 100, the center part 71 and the outer peripheral part 101 are integrally shape | molded with the thermoplastic resin. In the second partition plate 100, the outer peripheral portion 101 is formed in a curved shape in which the inner peripheral edge is in close contact with the outer wall surface 52 of the protrusion 54 of the elastic wall 50 and gradually moves away from the wall surface 52 toward the outer side in the radial direction.

  The second partition plate 100 constitutes a second contact portion 102 in which the entire central portion 71 contacts the wall surface 52 of the elastic wall 50 in a no-load state (a state before the weight of the engine is loaded). The size of the projection surface projected in the axial direction of the second contact unit 102 is set smaller than that of the first contact unit 65 projected in the axial direction. In the second partition plate 100, the outer edge of the second contact portion 102 is positioned closer to the center side (the connecting portion 73 side) than the radially outer edge of the recess 56 formed in the elastic wall 50.

  In the second partition plate 100, a peripheral portion 103 connected to the second contact portion 102 is located around the second contact portion 102. The peripheral portion 103 is a portion that is disposed at a distance in the axial direction from the elastic wall 50. In the present embodiment, the peripheral portion 103 is formed in a curved shape that gradually increases in the axial direction as it goes radially outward. . The peripheral portion 103 is set to have a curvature larger than that of the wall surface 52 of the elastic wall 50. The outer edge of the peripheral portion 103 is located on the outer side in the radial direction from the outer edge of the concave portion 56 in the radial direction.

  According to the third embodiment, when a fine amplitude vibration in a high frequency range is input, the first liquid chamber 23 is reciprocated together by the first partition plate 60 and the second partition plate 100. The vibration can be reduced by absorbing the hydraulic pressure. On the other hand, when large-amplitude vibration in a low frequency range is input, the first partition plate 60 (particularly the first contact portion 65) is used when the first liquid chamber 23 is displaced under pressure (compression input of the vibration-isolating base 17). Therefore, the displacement of the elastic wall 50 is restricted, so that a high damping coefficient can be obtained by the orifice 25. At the time of negative pressure displacement of the first liquid chamber 23 (tensile input of the vibration isolation base 17), the effect of regulating the displacement of the elastic wall 50 by the second partition plate 100 is less than that of the first partition plate 60. 50 can be easily bent and deformed toward the first liquid chamber 23. Due to the deformation of the elastic wall 50, rapid decompression of the first liquid chamber 23 can be prevented, and cavitation can hardly occur in the first liquid chamber 23.

  The second partition plate 100 has a peripheral portion 103 formed outside the second contact portion 102, and the peripheral portion 103 is separated from the elastic wall 50 in the axial direction. The amount of elastic deformation of the elastic wall 50 is ensured by the distance between the elastic wall 50 and the displacement of the elastic wall 50 can be restricted when the elastic wall 50 and the peripheral portion 103 interfere with each other. Since the amount of deformation of the elastic wall 50 toward the first liquid chamber 23 can be limited, the durability of the elastic wall 50 can be ensured while enhancing the effect of suppressing cavitation.

  In the second partition plate 100 attached to the elastic wall 50, the outer edge of the second contact portion 102 is positioned radially inward from the concave portion 56 (the outer edge in the radial direction). The function of limiting deformation can be suppressed. Therefore, the spring of the elastic wall 50 can be softened by the recess 56.

  The concave portion 56 formed in the elastic wall 50 is such that a radially outer edge (wall surface 52) is in close contact with the second partition plate 100 in a neutral position (no load state) where no load is applied to the elastic wall 50. There is no gap between the second partition plate 100 and the second partition plate 100. The gap can have a function as a high-frequency orifice that operates in a higher frequency range than the orifice 25. During large amplitude vibration, the second partition plate 100 is relatively displaced in the axial direction so that the gap is closed by the second partition plate 100. Therefore, high attenuation performance by the orifice 25 can be ensured.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the shape of the first partition plate 60 and the second partition plates 70, 90, 100, the number and size of the recesses 56 are not limited to those described in the embodiment, and can be set as appropriate.

  In each of the above embodiments, the second partition plates 70, 90, 100 are provided with the connection portions 73, and the connection portions 73 are inserted into the fitting recesses 63 formed in the first partition plates 60, Although the case where the 2nd partition plates 70, 90, and 100 were connected was demonstrated, it is not necessarily restricted to this. For example, a fitting recess is formed in the second partition plates 70, 90, 100, a connecting portion is provided in the first partition plate 60, and the first partition plate 60 is inserted into the fitting recess of the second partition plates 70, 90, 100. It is naturally possible to connect the first partition plate 60 and the second partition plates 70, 90, and 100 by inserting a connecting portion. Moreover, it replaces with the connection part 73, forms a recessed part in the 2nd partition plates 70, 90, 100, and uses the member (connection part) different from the 1st partition plate 60 and the 2nd partition plates 70, 90, 100, It is naturally possible to connect the first partition plate 60 and the second partition plates 70, 90, 100 by inserting another member (connecting portion) into the recess.

  In each of the above embodiments, the case where the liquid-filled vibration isolator 10 is used as an engine mount that elastically supports an automobile engine has been described. However, the present invention is not necessarily limited thereto. Of course, the liquid-filled vibration isolator 10 can be applied to a vibration isolator that suppresses vibration of an arbitrary vibrating body such as a body mount or a differential mount.

  Although description is omitted in each of the above embodiments, it is naturally possible to apply the partitions 30, 80, 81 to an active vibration isolator in which an actuator that reciprocates the elastic film 50 in the axial direction is arranged.

  In each of the embodiments described above, the first liquid chamber 23 and the second liquid chamber 24 are formed by the partition bodies 30, 80, 81, and the first liquid chamber 23 and the second liquid chamber 24 are connected by the orifice 25. However, the present invention is not necessarily limited to this. For example, it is naturally possible to add an orifice that connects between the first liquid chamber 23 and the second liquid chamber 24 in accordance with the required vibration isolation performance. In addition to the first liquid chamber 23 and the second liquid chamber 24, it is naturally possible to have one or more sub liquid chambers. In this case, two liquid chambers among the first liquid chamber 23, the second liquid chamber 24, and the sub liquid chamber can be communicated with each other by one or more orifices other than the orifice 25.

  Although description is omitted in each of the above embodiments, the shape of the wall surfaces 51 and 52 of the elastic membrane 50, the shape of the first partition plate 60 and the second partition plates 70, 90, and 100, the length of the connecting portion 73, and the like are set. Thus, when connecting the first partition plate 60 and the second partition plates 70, 90, 100, the first partition plate 60 and the second partition plates 70, 90, 100 are pressed against the wall surfaces 51, 52 of the elastic membrane 50. Of course, it is possible to pre-compress part of the elastic membrane 50 in the axial direction. Thereby, the spring constant of the partition 30, 80, 81 (elastic wall 50), the ease of deformation | transformation of the elastic wall 50, etc. can be adjusted.

DESCRIPTION OF SYMBOLS 10 Liquid enclosure type vibration isolator 11 1st attachment 13 Second attachment 17 Anti-vibration base | substrate 20 Diaphragm 23 1st liquid chamber (a part of liquid chamber)
24 Second liquid chamber (part of liquid chamber)
25 Orifice 30, 80, 81 Partition 31 Orifice forming member 50 Elastic wall 60 First partition plate 65 First contact portion 70, 90, 100 Second partition plate 73 Connection portion 74, 92, 102 Second contact portion 103 Peripheral portion

Claims (2)

A first fixture and a cylindrical second fixture;
An anti-vibration base composed of a rubber-like elastic body connecting the first fixture and the second fixture;
A diaphragm composed of a rubber-like elastic body that is attached to the second fixture and forms a liquid chamber in which a liquid is sealed between the anti-vibration base;
A partition that divides the liquid chamber into a first liquid chamber on the vibration-proof base side and a second liquid chamber on the diaphragm side;
The partition is formed with an annular orifice forming member disposed inside the second fixture, forming an orifice communicating the second liquid chamber and the first liquid chamber;
An elastic wall composed of a rubber-like elastic body whose periphery is bonded to the orifice forming member;
A first partition plate facing the first liquid chamber and a second partition plate facing the second liquid chamber, which are coupled to each other via a coupling portion penetrating the center of the elastic wall;
The first partition plate includes a first contact portion that is located around the connection portion and contacts the elastic wall in an unloaded state;
The second partition plate includes a second contact portion that is located around the coupling portion and contacts the elastic wall in an unloaded state,
The liquid contact type prevention device characterized in that the size of the outer edge of the projection surface projected in the axial direction is set smaller than the outer edge of the projection surface of the first contact portion projected in the axial direction. Shaker. The second partition plate includes a peripheral portion connected to the second contact portion and positioned around the second contact portion,
The liquid-filled vibration isolator according to claim 1, wherein the peripheral portion is disposed at a distance in the axial direction from the elastic wall.

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