JP6240397B2 - 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 secure the deformation amount and durability of a diaphragm, can prevent the negative pressure introduction tube from being damaged, and can reduce the trouble of mounting. is there.

  In a vehicle such as an automobile, a vibration isolator that suppresses transmission of vibration to the vehicle body side is provided between a vibration generation source such as an engine and a vehicle body that receives vibration. As such a vibration isolator, for example, a control-type liquid-filled vibration isolator disclosed in Patent Document 1 is known. According to the technique disclosed in Patent Document 1, a diaphragm that forms a liquid chamber with a vibration-proof substrate is deformed in accordance with pressure fluctuations in the liquid chamber, and exhibits a high damping effect and a vibration insulating effect. Furthermore, the vibration isolation characteristics can be switched based on the action of negative pressure or atmospheric pressure introduced from the outside.

Japanese Patent Laid-Open No. 6-264958

  However, in the above-described technique, the negative pressure introduction pipe into which negative pressure or atmospheric pressure is introduced protrudes from the side surface of the liquid-filled vibration isolator formed in a substantially cylindrical shape. If the liquid-filled vibration isolator rolls over, etc., the negative pressure introducing pipe protruding from the side surface may be damaged.

  In addition, the negative pressure inlet pipe protrudes in one direction from the side of the liquid-filled vibration isolator, so when mounting on a vehicle, negative pressure is introduced in the direction of the external conduit on the vehicle side connected to the negative pressure inlet pipe. The liquid-filled vibration isolator must be attached to the vehicle with the direction of the tube adjusted. For this reason, there is a problem that the time and labor required for attachment to the vehicle increases.

  In addition, a diaphragm that deforms due to pressure fluctuations in the liquid chamber needs to ensure a deformation amount and durability in order to ensure vibration absorption performance.

  The present invention has been made to solve the above-described problems, and is a liquid-filled type that can ensure the amount of deformation and durability of the diaphragm, can make it difficult to break the negative pressure introduction tube, and can reduce the trouble of mounting. The object is to provide a vibration isolator.

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 mounting member and the cylindrical second mounting member are connected by the vibration isolating base composed of a rubber-like elastic body. The A liquid sealing chamber is formed between the first diaphragm fixed to the second mounting member and the vibration-proof base. The liquid enclosure chamber is partitioned into a plurality of liquid chambers by a partition, and the plurality of liquid chambers communicate with each other through an orifice. The second diaphragm is configured to be deformable by pressure fluctuations in the liquid chamber accompanying elastic deformation of the vibration-proof base, and an air chamber is formed between the second diaphragm and the partition. The air line communicating with the air chamber communicates with the negative pressure introducing pipe, and negative pressure or atmospheric pressure is introduced into the air chamber from an external line connected to the negative pressure introducing pipe.

  The air pipe passes through the first diaphragm and the partition, and is provided at a central portion in the radial direction of the first diaphragm and the partition. The negative pressure introduction tube is provided at a central portion in the radial direction of the first diaphragm. Therefore, it is possible to prevent the negative pressure introducing tube from protruding on the side surface of the liquid-filled vibration isolator. As a result, even if the liquid-filled vibration isolator rolls during transportation or mounting on a vehicle, the negative pressure introduction pipe can be hardly damaged.

  In addition, since the negative pressure introduction pipe is provided in the radial center of the first diaphragm, the direction of the negative pressure introduction pipe is set to the direction of the external conduit on the vehicle side connected to the negative pressure introduction pipe when mounted on the vehicle. The work of matching can be omitted. Therefore, there is an effect that it is possible to reduce time and effort at the time of attachment to the vehicle.

  Further, since the first diaphragm is formed in a bellows shape having concentric concavities and convexities around the negative pressure introduction tube as viewed from the axial center direction of the second mounting member, the deformation amount of the first diaphragm can be ensured. In addition, since the plurality of convex portions protrude in the axial direction and are provided with a plurality of concentric convex portions, the circumferential length of the convex portion relatively located on the inner peripheral side is the length of the convex portion adjacent to the convex portion. It becomes smaller than the circumference. Therefore, when a plurality of convex portions protrude in the axial direction with the same size, when the first diaphragm extends, the relative deformation amount of the convex portion located on the innermost side is the convex portion. It becomes larger than the relative deformation amount of the convex portion located on the outer peripheral side. Therefore, the tensile strain generated in the convex portion located on the innermost peripheral side is larger than the tensile strain generated in the convex portion located on the outer peripheral side from the convex portion.

On the other hand, when the first diaphragm is extended by making the convex portion located on the innermost peripheral side project more greatly in the axial direction than the convex portion located on the outer peripheral side from the convex portion, The relative deformation amount of the convex portion located on the side can be reduced. As a result, it is possible to reduce the tensile strain generated in the convex portion located on the innermost peripheral side. Thereby, there exists an effect which can ensure durability, ensuring the deformation amount of a 1st diaphragm.
Conduit forming member includes a shaft portion air line is penetrated formed through the first diaphragm, and a disk portion which is protruded in a flange shape toward the shaft portion radially outward. A 1st diaphragm is provided with the cyclic | annular inner periphery part comprised from the rubber-like elastic body into which an axial part is inserted in an inner peripheral side, and the liquid sealing part provided in the radial inside of an inner peripheral part. Conduit forming member, the inner peripheral edge portion so fixed in a non-bonding the pressed inside periphery in the axial direction between the disc portion and the partition side, compared with the case where the first diaphragm is affixed by vulcanization And cost reduction.
In addition, since the convex portion located on the innermost circumferential side protrudes more in the axial direction than the convex portion located on the outer circumferential side from the convex portion, the tensile strain generated in the convex portion located on the innermost circumferential side can be reduced. . As a result, the amount of deformation in the vicinity of the inner peripheral edge portion of the first diaphragm can be reduced, so that when the inner peripheral edge portion of the first diaphragm is fixed non-adhered, the risk of liquid leakage therefrom can be reduced.
In a state where the inner peripheral edge is compressed and deformed in the axial direction by the disk portion and the partitioning body side, the liquid seal portion contacts the outer peripheral surface of the shaft portion while the outer peripheral surface of the inner peripheral edge is in contact with the wall portion, A gap is provided between the inner peripheral edge portion and part of the liquid seal portion and the shaft portion. The wall portion that contacts the outer peripheral surface of the inner peripheral edge portion restricts the movement of the inner peripheral edge portion toward the radially outer side, so that a tensile force outwardly in the radial direction acts on the inner peripheral edge portion, resulting in a decrease in sealing performance. Can be suppressed.

  According to the liquid-filled vibration isolator according to claim 2, the plurality of convex portions of the convex portions relatively located on the inner peripheral side protrude larger in the axial direction than the convex portions adjacent to the convex portions. Therefore, it is possible to reduce the tensile strain generated in the convex portion having a relatively small circumferential length (the convex portion positioned relatively on the inner peripheral side). Thereby, in addition to the effect of Claim 1, even if three or more convex portions are formed concentrically on the first diaphragm, there is an effect that the durability of the first diaphragm can be ensured.

  According to the liquid-filled vibration isolator according to claim 3, the sum of the axial dimension of the inner peripheral surface and the axial dimension of the outer peripheral surface of the convex portion located on the innermost peripheral side is the outer peripheral side from the convex portion. Is larger than the sum of the axial dimension of the inner circumferential surface and the axial dimension of the outer circumferential surface of the convex portion located at the position of the convex portion located at the position of the convex portion located on the innermost circumferential side when the first diaphragm extends. The amount of deformation can be made sufficiently small. As a result, in addition to the effect of the first or second aspect, there is an effect that the tensile strain generated in the convex portion located on the innermost side can be sufficiently reduced.

  According to the liquid-filled vibration isolator according to claim 4, the plurality of convex portions have a radius of curvature at the tip of the convex portion located relatively on the outer peripheral side in a cross-sectional view including the axis of the second mounting member. The radius of curvature of the tip of the convex portion adjacent to the convex portion is set to the same value. As a result, it is possible to prevent the distortion generated in the convex portion from being biased when the first diaphragm is extended. Thereby, in addition to the effect in any one of Claims 1-3, it can prevent that the load of a specific convex part becomes large.

  According to the liquid-filled vibration isolator according to claim 5, the plurality of convex portions have a radius of curvature at the tip of the convex portion located relatively on the outer peripheral side in a cross-sectional view including the axis of the second mounting member. , A value different from the radius of curvature of the tip of the convex portion adjacent to the convex portion is set. If the radius of curvature of the tip of the convex portion positioned relatively on the outer peripheral side is set smaller than the radius of curvature of the tip of the convex portion adjacent to the convex portion, the convex portion positioned relatively on the outer peripheral side can be easily restored. it can. Also, if the radius of curvature of the tip of the convex portion positioned relatively on the outer peripheral side is set larger than the radius of curvature of the tip of the convex portion adjacent to the convex portion, the convex portion positioned relatively on the outer peripheral side is deformed. Easy to do. Thereby, in addition to the effect in any one of Claims 1-3, there exists an effect which can set the required characteristic of a 1st diaphragm suitably.

It is an axial sectional view of the liquid filled type vibration isolator in the first embodiment of the present invention. It is an expanded sectional view of a liquid enclosure type vibration isolator. It is a fragmentary sectional view of the 1st diaphragm. It is an expanded sectional view of the liquid filling type vibration isolator in 2nd Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is an axial sectional view of a liquid filled type vibration damping device 1 according to a first embodiment of the present invention. As shown in FIG. 1, a liquid-filled vibration isolator 1 includes a first attachment member 2 attached to a power unit (not shown) such as an automobile engine, and a vehicle body below the power unit via a bracket (not shown). A cylindrical second mounting member 3 mounted on a frame (not shown), and a vibration-proof base 4 that connects the first mounting member 2 and the second mounting member 3 and is made of a rubber-like elastic body are provided. ing.

  In the present embodiment, the shared support load of the power unit is input in the direction of the axis O passing through the axis (the vertical direction in FIG. 1). Accordingly, in the mounted state, the first mounting member 2 and the second mounting member 3 are displaced in the axial direction toward each other due to elastic deformation of the vibration-proof base 4. In the following description, the vertical direction means the vertical direction of the axis O in FIG. 1 unless otherwise specified.

  As shown in FIG. 1, the first mounting member 2 is mainly formed of a rigid material such as a metal material, and a bolt hole 2a is provided on the upper surface. A bolt (not shown) attached to the bracket of the power unit is fastened and fixed to the bolt hole 2a, whereby the first attachment member 2 is attached to the vibration source. The second attachment member 3 is formed in a cylindrical shape mainly from a rigid material such as a metal material, and is attached to the vehicle body frame side (not shown) via a bracket or the like.

  The anti-vibration base 4 is formed in a truncated cone shape, and its upper end is vulcanized and bonded to the outer peripheral surface of the first mounting member 2 and its lower end is bonded to the upper inner peripheral surface of the second mounting member 3. An upper constricted hollow portion is formed on the lower surface side of the vibration isolating base 4, and a rubber film 5 covering the inner peripheral surface of the second mounting member 3 is continuously provided on the stepped portion 4 a at the lower end of the vibration isolating base 4. Is done. As for the 2nd attachment member 3, the cylindrical bracket member 6 is externally fitted by the upper end part, and the stopper rubber 7 is adhere | attached on the upper end part of the bracket member 6. FIG.

  Inside the second mounting member 3, the liquid chamber forming member 10 and the partition 20, the second diaphragm 30 disposed between the liquid chamber forming member 10 and the partition 20, and the first diaphragm 40 are fixed. Then, the pipe line forming member 50 is fixed to the partition body 20. With reference to FIG. 2, the liquid chamber forming member 10, the partition 20, the second diaphragm 30, the first diaphragm 40 and the pipe line forming member 50 will be described. FIG. 2 is an enlarged cross-sectional view of the liquid-filled vibration isolator 1. In FIG. 2, illustration of the upper side (first mounting member 2 and the like) of the liquid-filled vibration isolator 1 is omitted.

  As shown in FIG. 2, the liquid chamber forming member 10 is a member formed in a circular shape when viewed in the axial direction (viewed in the direction of the axis O), and the main body portion 11 formed in a disk shape, A collar portion 12 projecting in a bowl shape toward the radial direction of the main body portion 11 over the entire circumference, and a cylindrical cylindrical portion 13 projecting from the peripheral edge of the main body portion 11 toward the axial direction are provided. Yes. A second orifice (through hole) 10a penetrating in the thickness direction is formed in the central portion in the radial direction of the main body 11, and a cylindrical tube wall portion 14 is provided around the second orifice 10a.

  The partition 20 is a member for partitioning the liquid enclosure chamber L into a first liquid chamber L1 (see FIG. 1) and a second liquid chamber L2, and the liquid chamber forming members 10 are stacked, and viewed in the axial direction (axis O It is formed in a circular shape when viewed from the direction. The partition 20 is formed in a bowl shape toward the radial direction of the main body 21 over the entire periphery of the main body 21 and the main body 21 having a concave surface facing the liquid chamber forming member 10. And an annular portion 22. Further, the partition 20 is a stepped portion 23 formed in a step shape in the axial direction over the entire circumference of the annular portion 22, and a cylindrical shape extending in the axial direction over the entire outer circumference in the radial direction of the stepped portion 23. The outer peripheral wall portion 24 and orifice forming wall portions 25 and 26 extending in a flange shape from both axial ends of the outer peripheral wall portion 24 toward the radially outer side. Further, a cylindrical wall portion 27 projects from the opposite surface of the main body 11 facing the liquid chamber forming member 10 in the axial direction.

  The outer peripheral wall portion 24 and the orifice forming wall portions 25 and 26 are portions for forming the first orifice 20b that allows the first liquid chamber L1 and the second liquid chamber L2 to communicate with each other. Each has a notch (not shown). The liquid flows between the first liquid chamber L1 and the second liquid chamber L2 through the notches and the outer periphery (first orifice 20b) of the outer peripheral wall portion 24. Further, the main body portion 21 is formed with a through hole 20a (air pipe line) penetrating in the thickness direction (axial direction) in the central portion in the radial direction.

  The second diaphragm 30 is a member (rubber film) made of a rubber-like elastic body, and is formed in a circular shape when viewed in the axial direction. The second diaphragm 30 includes a convex surface portion 31 that is formed in a convex spherical shape that is convex upward in the axial direction (upper side in FIG. 2), and a concave curved surface that is connected to the outer peripheral edge of the convex surface portion 31 and concave in the axial direction. A concave surface portion 32 formed in an annular shape, an extended portion 33 that is continuous with the outer peripheral edge of the concave surface portion 32 and extends outward in the radial direction, and continuous with the entire circumference of the extended portion 33. And an outer peripheral edge portion 34 whose axial dimension is set larger than that of the extending portion 33.

  The liquid chamber forming member 10 is press-fitted into the partition 20 with the second diaphragm 30 interposed, and the second diaphragm 30 is airtightly fixed to the partition 20 and the liquid chamber forming member 10. Specifically, the extension portion 33 and the outer peripheral edge portion 34 of the second diaphragm 30 are overlapped with the annular portion 22 and the step portion 23 of the partition body 20, and the orifice forming wall portion 25 and the liquid chamber forming member of the partition body 20 are overlapped. The extending portion 33 is pressed by the cylindrical portion 13 in a state where the ten flange portions 12 are in contact with each other. An air chamber R is formed between the partition 20 and the second diaphragm 30 by airtightly holding (adhering) the second diaphragm 30 to the partition 20 and the liquid chamber forming member 10.

  The first diaphragm 40 is a member (rubber film) made of a rubber-like elastic body so as to form a liquid sealing chamber L (see FIG. 1) sealed to the outside, and is thinner than the second diaphragm 30. It is formed in a large-diameter annular shape. The liquid enclosure L is filled with incompressible liquid (hereinafter referred to as “liquid”) such as water or ethylene glycol. The first diaphragm 40 is formed in a bellows shape having concentric convex portions 41 and 42 and a concave portion 43 around the radial center portion (inner peripheral edge portion 45) when viewed in the direction of the axis O. The outer peripheral edge portion is vulcanized and bonded to the cylindrical support fitting 47, and the inner peripheral edge portion 45 is fixed to the pipe line forming member 50. In the first diaphragm 40, the axial dimension (the vertical dimension in FIG. 2) of the inner peripheral edge 45 is set to be larger than the axial dimension (thickness) of the convex parts 41, 42, the concave part 43 and the neck part 44. And the inner peripheral edge 45 are connected to the neck 44. In addition, liquid sealing portions 46 having a triangular cross section are provided at two locations on the inner peripheral surface of the inner peripheral edge portion 45 so as to protrude radially inward over the entire circumference.

  The duct forming member 50 is a member that fixes the inner peripheral edge 45 of the second diaphragm 30 and is formed with an air duct 50a penetrating in the axial direction. The pipe line forming member 50 includes a shaft portion 52 formed in a columnar shape, a disk-shaped disk portion 51 projecting in a bowl shape from one end portion of the shaft portion 52 toward the radially outer side, and the disk portion 51 A cylindrical peripheral wall portion 53 projecting from the outer peripheral edge in the axial direction on the shaft portion 52 side, and a negative pressure introduction pipe 54 formed concentrically with the shaft portion 52 are provided. The air duct 50 a is formed through the shaft portion 52 and the negative pressure introduction pipe 54.

  The pipe line forming member 50 is fixed to the partition 20 by various means such as screwing, welding, and fitting. By fixing the duct forming member 50 to the partition body 20, the air duct 50a communicates with the air chamber R through the through hole 20a. In addition, the pipe forming member 50 is fixed to the partition body 20, whereby the inner peripheral edge 45 of the first diaphragm 40 is fixed in an airtight manner.

  Next, the elastic deformation behavior of the inner peripheral edge portion 45 and the liquid seal portion 46 when the first diaphragm 40 is sandwiched between the partition body 20 and the pipe line forming member 50 will be described with reference to FIG. FIG. 3 is a partial cross-sectional view of the first diaphragm 40. In FIG. 3, the first diaphragm 40 before being sandwiched between the partition body 20 and the pipe line forming member 50 is shown by a two-dot chain line, and the first diaphragm after being sandwiched between the partition body 20 and the pipe line forming member 50. The diaphragm 40 is illustrated by a solid line.

  As shown in FIG. 3, the axial direction (vertical direction in FIG. 3) dimension of the inner peripheral edge 45 (two-dot chain line) of the first diaphragm 40 before clamping is the axial direction between the main body 21 and the disk 51 after clamping. It is set larger than the interval. As a result, the inner peripheral edge 45 after being sandwiched is compressed and deformed in the axial direction by the main body 21 and the disk 51. Since the elastic deformation (reduced diameter) of the inner peripheral edge 45 toward the radially outer side is restricted by the wall 27 and the peripheral wall 53, the inner peripheral edge 45 extends radially inward (right side in FIG. 3). The radial dimension of the inner peripheral edge 45 and the liquid sealing part 46 is set slightly smaller than the radial dimension between the shaft part 52 and the wall part 27 and the radial dimension between the shaft part 52 and the peripheral wall part 53. Since the inner peripheral edge 45 extends in the radial direction, the liquid sealing parts 46 are pressed against the outer peripheral surface of the shaft part 52, respectively. Further, since the inner peripheral edge 45 is set to have a smaller radial dimension than the axial dimension, the inner peripheral edge 45 can be compressed with a small axial load by the main body 21 and the disk part 51.

  As a result, the space between the main body portion 21 and the disk portion 51 and the axial end surface of the inner peripheral edge portion 45 and the space between the liquid sealing portion 46 and the outer peripheral surface of the shaft portion 52 can be liquid-tight. Furthermore, since a part of the axial direction of the inner peripheral edge 45 protrudes in the radial direction over the entire circumference of the liquid sealing part 46, the liquid sealing part 46 comes into close contact with the shaft part 52, whereby the liquid sealing part 46. The area where the pressing force is applied can be reduced. As a result, sealing performance can be secured even with a small pressing force.

  Therefore, a stable sealing action against pressure fluctuations and vibrations of the liquid sealed in the liquid sealing chamber L can be secured without vulcanizing and bonding the pipe forming member 50 and the first diaphragm 40. Further, since the vulcanization adhesion between the pipe forming member 50 and the first diaphragm 40 can be omitted, the liquid-filled vibration isolator 1 can be manufactured at a lower cost.

  The axial dimension (thickness) of the neck portion 44 before clamping is set to be larger than the axial interval between the wall portion 27 and the peripheral wall portion 53 after clamping. Thereby, the neck part 44 after clamping is pinched | interposed into the axial direction edge part of the wall part 27 and the surrounding wall part 53 which oppose, and is compressed and deformed to an axial direction. The elastic deformation (extension) of the neck portion 44 radially outward is restricted by the elastic deformation (extension in the radial direction) of the inner peripheral edge 45, so the neck portion 44 is axially formed by the wall portion 27 and the peripheral wall portion 53. Pressed and pinched.

  Here, when the neck portion 44 is not pressed in the axial direction, when the first diaphragm 40 (see FIG. 2) reciprocates in the axial direction, the inner peripheral edge portion 45 is moved radially outward through the neck portion 44. The tension force acts on the neck portion 44 and the neck portion 44 moves (swings) in the axial direction. If it does so, there exists a possibility that the sealing performance of the inner peripheral part 45 may also fall.

  On the other hand, according to the present embodiment, by pressing the neck portion 44 in the axial direction, the tensile force acting on the inner peripheral edge portion 45 and the movement of the neck portion 44 in the axial direction can be suppressed. As a result, it is possible to suppress deterioration in the sealing performance of the neck portion 44, the inner peripheral edge portion 45, and the liquid sealing portion 46.

  Moreover, since the convex part 44a protrudes in the axial direction over the entire circumference of the neck part 44, the area where the pressing force is applied to the contact area by the convex part 44a can be reduced. As a result, sealing performance can be secured even with a small pressing force.

  The convex portion 44a is not provided on the upper side surface in the axial direction of the neck portion 44 (surface close to the vibration isolation base 4), but is provided on the lower side surface in the axial direction (surface separated from the vibration isolation base 4). . The upper side surface in the axial direction of the neck portion 44 is continuous with the inner surface of the first diaphragm 40 with which the liquid sealed in the liquid sealing chamber L contacts, but the lower side surface in the axial direction of the neck portion 44 (the surface on which the convex portion 44a is provided). Is continuous with the outer surface of the first diaphragm 40 where no liquid is present. In some cases, wrinkles in the circumferential direction may be formed at the root of the convex portion 44a pressed against the peripheral wall portion 53, but since no liquid exists on the surface (the outer surface of the first diaphragm 40), the sealing property due to the wrinkles. Can be prevented (leakage).

  Further, the liquid sealing part 46 is located on the radially inner side (right side in FIG. 3) of the inner peripheral edge part 45. When the liquid sealing portion 46 is positioned on the radially outer side of the inner peripheral edge portion 45, a radially outward tensile force (vibration) acts on the inner peripheral edge portion 45 along with the axial reciprocation of the first diaphragm 40. The pressing force of the liquid sealing part 46 against the mating surface (shaft part 52) is likely to vary. If it does so, there exists a possibility that the sealing performance of the liquid sealing part 46 may fall. On the other hand, since the liquid sealing part 46 is positioned on the inner side in the radial direction of the inner peripheral edge part 45, the tensile force to the outer side in the radial direction can be buffered by the inner peripheral edge part 45. The fluctuation of the pressing force on 52 can be suppressed. Therefore, it is possible to suppress a decrease in the sealing action by the liquid sealing part 46.

  Returning to FIG. The liquid filled vibration isolator 1 shown in FIG. 1 is manufactured as follows, for example. First, the liquid chamber forming member 10 is press-fitted into the partition body 20, and the second diaphragm 30 is sandwiched between the liquid chamber forming member 10 and the partition body 20. The inner peripheral edge 45 of the first diaphragm 40 to which the support metal fitting 47 is vulcanized and bonded is held by the pipe line forming member 50, and the pipe line forming member 50 is fixed to the partition body 20. After the liquid is filled in the second mounting member 3 in which the anti-vibration base 4 is vulcanized and bonded to the first mounting member 2, the liquid forming member 10, the partition 20 and the support fitting 47 are inserted into the second mounting member 3. The second mounting member 3 is subjected to a drawing process so that the liquid chamber forming member 10, the partition 20, and the support fitting 47 are liquid-tight between the vibration isolating base 4 and the rubber film 5.

  The liquid enclosure chamber L of the liquid enclosure type vibration isolator 1 includes a first liquid chamber L1 between the vibration isolation base 4 and the liquid chamber forming member 10, and a second liquid chamber between the partition body 20 and the first diaphragm 40. L2 is partitioned into a third liquid chamber L3 between the liquid chamber forming member 10 and the second diaphragm 30. An air chamber R is formed between the second diaphragm 30 and the partition body 20. An air pressure adjusting device 60 is connected to the air pipe 50 a communicating with the air chamber R.

  The air pressure adjusting device 60 is a device for introducing a negative pressure or an atmospheric pressure into the air chamber R, and includes an external pipe 63 on the vehicle body side connected to the pipe forming member 50 (the air pipe 50a), and an external pipe. A negative pressure source 61 and a switching valve 62 connected to the path 63 are included. The switching valve 62 is configured by an electromagnetic valve or the like, and can selectively switch communication between the negative pressure source 61 or the atmosphere and the air chamber R. As the negative pressure source 61, for example, a pressure absorber system or an accumulator on the intake side of an automobile is employed.

  The switching valve 62 is connected to a control device (not shown). The control device receives various types of information representing the state of the vehicle, such as the traveling speed of the vehicle, the engine speed, the shift position selection position, and the throttle opening, from various sensors provided in the vehicle. The control device operates the switching valve 62 based on the various information input.

  According to the liquid-filled vibration isolator 1, when the air chamber R is opened to the atmosphere by the switching valve 62, the second diaphragm 30 can be moved. On the other hand, when negative pressure is introduced into the air chamber R by the switching valve 62, the rigidity of the second diaphragm 30 is increased by bringing the second diaphragm 30 into contact with the main body portion 21 of the partition body 20 to be in a restrained state. be able to. By changing the rigidity of the second diaphragm 30 in this manner, vibrations with different frequencies such as shake vibration and idling vibration of the power unit can be effectively attenuated.

  The air duct 50a that penetrates the first diaphragm 40 and the through hole 20a that penetrates the partition 20 are provided in the radial center of the first diaphragm 40 and the partition 20, and the negative pressure introduction pipe 54 is connected to the first diaphragm 40. Is provided at the center in the radial direction. Therefore, it is possible to prevent the negative pressure introducing pipe 54 from protruding from the side surface of the liquid-filled vibration isolator 1. As a result, even if the liquid-filled vibration isolator 1 rolls during transportation or mounting on a vehicle, the negative pressure introduction tube 54 can be hardly damaged.

  Further, since the negative pressure introduction pipe 54 is provided in the central portion in the radial direction of the first diaphragm 40, when mounted on the vehicle, the negative pressure introduction pipe 54 is directed toward the vehicle-side external pipe 63 connected to the negative pressure introduction pipe 54. The operation of aligning the direction of the tube 54 can be omitted. Therefore, the trouble at the time of attachment of the liquid filled type vibration isolator 1 to a vehicle can be reduced.

  Next, the first diaphragm 40 will be described with reference to FIG. The first diaphragm 40 is formed in a bellows shape, and has concentric convex portions 41 and 42 and concave portions 43 around the negative pressure introduction tube 54 when viewed from the direction of the axis O, and includes a plurality of convex portions 41 in the axis O direction. 42 protrudes. Since the first diaphragm 40 is formed in a bellows shape, the amount of deformation can be increased while reducing the radial dimension. As a result, the liquid-filled vibration isolator 1 can be reduced in size (smaller diameter) without deteriorating the vibration absorption performance due to the deformation of the first diaphragm 40. Further, since it is a part of the first diaphragm 40 (recess 43) that reverses outward (becomes convex) according to the pressure fluctuation in the second liquid chamber L2, it is possible to reduce noise generated during the reversal.

  The plurality of convex portions 41, 42 constituting the first diaphragm 40 is such that the convex portion 41 (axial length L 1) located on the inner peripheral side is the convex portion 42 (axial) positioned on the outer peripheral side from the convex portion 41. It projects larger in the axial direction than in the direction length L2) (L1> L2). In the present embodiment, the thicknesses (film thicknesses) of the convex portions 41 and 42 and the concave portion 43 are set to be the same.

  Here, since the convex portions 41 and 42 are formed concentrically, the circumferential length of the convex portion 41 relatively located on the inner peripheral side is smaller than the circumferential length of the convex portion 42 adjacent to the convex portion 41. Since both the inner peripheral edge 45 and the outer peripheral edge (support metal fitting 47) are fixed to the first diaphragm 40, if the convex portions 41 and 42 protrude with the same size in the axial direction (L1 = L2) When the first diaphragm 40 is extended, the relative deformation amount of the convex portion 41 positioned on the inner peripheral side is larger than the relative deformation amount of the convex portion 42 positioned on the outer peripheral side of the convex portion 41. Become. Therefore, the tensile strain generated in the convex portion 41 located on the inner peripheral side is larger than the tensile strain generated in the convex portion 42 positioned on the outer peripheral side from the convex portion 41. If it does so, there exists a possibility that the convex part 41 may deteriorate earlier than the convex part 42. FIG.

  On the other hand, according to the present embodiment, the convex portion 41 located on the inner peripheral side protrudes larger in the axial direction than the convex portion 42 located on the outer peripheral side from the convex portion 41, so that the first diaphragm 40 is The relative deformation amount of the convex portion 41 when extending can be made smaller than the relative deformation amount of the convex portion 42. As a result, the tensile strain generated in the convex portion 41 located on the inner peripheral side can be reduced. Thereby, it can prevent that the convex part 41 deteriorates earlier than the convex part 42, and can ensure the durability of the 1st diaphragm 40. FIG. Therefore, it is possible to ensure durability while ensuring the deformation amount of the first diaphragm 40.

  Further, if the convex portions 41 and 42 protrude in the axial direction with the same size (L1 = L2), the convex portion 41 is caused by relative pressure fluctuations in the first liquid chamber L1 and the second liquid chamber L2. , 42 repeats deformation (deformation that protrudes outward and inward), so that there is a problem that the recess 43 is likely to crack.

  On the other hand, the first liquid chamber L1 and the first liquid chamber L1 are formed by projecting the convex portion 41 located on the inner peripheral side more in the axial direction than the convex portion 42 positioned on the outer peripheral side from the convex portion 41 (L1> L2) The amount of deformation of the convex portions 41 and 42 when a relative pressure fluctuation occurs in the second liquid chamber L2 can be varied. Therefore, since the deformed portion between the convex portions 41 and 42 (the deformed portion that protrudes outward and inward) changes its position in the radial direction, compared to the case where only the portion of the concave portion 43 is repeatedly deformed, Cracks can be made difficult to occur. As a result, the durability of the first diaphragm 40 can be improved. Further, abnormal noise caused by the inversion of the recess 43 can also be suppressed.

  The ratio (L1 / L2) of the axial length L1 of the convex portion 41 to the axial length L2 of the convex portion 42 is preferably 1.1 to 5. As L1 / L2 becomes smaller than 1.1, the effect of preventing repeated deformation of the concave portion 43 located between the convex portions 41 and 42 and preventing the generation of cracks and abnormal noise tends to decrease. Further, as L1 / L2 becomes larger than 5, the length of the rubber film that can be deformed between the convex portions 41 and 42 becomes smaller, so that the deformation amount of the first diaphragm 40 tends to decrease (vibration absorption performance deteriorates). Is seen.

  Note that the convex portions 41 and 42 have a curvature radius R2 at the tip of the convex portion 42 that is relatively located on the outer peripheral side in a cross-sectional view (paper surface in FIG. 2) including the axis (axis O) of the second mounting member 3. The curvature radius R1 of the tip of the convex portion 41 adjacent to the convex portion 42 is set to the same value. Thereby, it can prevent that the distortion which arises in the convex parts 41 and 42 when the convex parts 41 and 42 elastically deformed arises. As a result, it is possible to prevent an increase in the load (distortion) of the specific convex portion, and thus durability can be improved.

  Further, the curvature radii R1, R2 of the convex portions 41, 42 are set to be the same as the curvature radius of the concave portion 43 (the inner surface of the concave portion 43). Thereby, the bias | inclination of the distortion which arises in the convex parts 41 and 42 and the recessed part 43 when the 1st diaphragm 40 elastically deforms by this can be suppressed.

  In addition, the convex parts 41 and 42 are the convex parts 41 adjacent to the convex part 42 by making the curvature radius of the front-end | tip of the convex part 42 located in the outer peripheral side relatively in the cross sectional view containing the axis of the 2nd attachment member 3 into. It is possible to set to a value different from the radius of curvature of the tip. If the radius of curvature R2 of the tip of the convex portion 42 is set to be smaller than the radius of curvature R1 of the tip of the convex portion 41 adjacent to the convex portion 42, the convex portion 42 positioned relatively on the outer peripheral side can be easily restored. Further, if the curvature radius R2 of the tip of the convex portion 42 is set larger than the curvature radius R1 of the tip of the convex portion 41, the convex portion 42 can be easily deformed. The same can be done by changing the thickness (film thickness) of the convex portions 41 and 42. Thus, the required characteristic of the 1st diaphragm 40 can be suitably set by setting the curvature radius and film thickness of the convex parts 41 and 42. FIG.

  Further, the inner peripheral edge 45 of the first diaphragm 40 is pressed in the axial direction (axis O direction) between the first diaphragm 40 and the inner peripheral edge 45 is fixed without being bonded. In order to prevent liquid leakage, it is necessary to fix the inner peripheral edge 45 in a liquid-tight manner. According to the present embodiment, since the convex portion 41 located on the inner peripheral side protrudes larger in the axial direction than the convex portion 42 located on the outer peripheral side from the convex portion 41, the tensile strain generated in the convex portion 41 is reduced. it can. As a result, the amount of deformation in the vicinity of the inner peripheral edge 45 of the first diaphragm 40 can be reduced, so that even if the inner peripheral edge 45 of the first diaphragm 40 is fixed non-adhered, the risk of liquid leakage can be reduced. .

  Next, a second embodiment will be described with reference to FIG. In 1st Embodiment, the case where the two convex parts 41 and 42 were formed in the 1st diaphragm 40 concentrically was demonstrated. In contrast, in the second embodiment, a case where three convex portions 141, 142, and 144 are formed concentrically on the first diaphragm 140 will be described. Note that in the second embodiment, the same portions as those described in the first embodiment are denoted by the same reference numerals, and the following description is omitted. FIG. 4 is an enlarged cross-sectional view of the liquid-filled vibration isolator 101 according to the second embodiment. In FIG. 4, illustration of the upper side (first mounting member 1 and the like) of the liquid-filled vibration isolator 101 is omitted.

  As shown in FIG. 4, the first diaphragm 140 of the liquid-filled vibration isolator 101 is formed in a bellows shape, and concentric convex portions 141, 142, 144 around the negative pressure introduction tube 54 as viewed from the direction of the axis O. And a plurality of convex portions 141, 142, 144 project in the direction of the axis O. The inner peripheral edge 45 of the first diaphragm 140 is sandwiched between the partition 20 and the pipe line forming member 150, and the liquid sealing part 46 of the first diaphragm 140 is the outer peripheral surface of the shaft part 152 of the pipe line forming member 150. Press. Thereby, the inner peripheral edge 45 of the first diaphragm 140 is fixed without adhesion.

  As for the convex parts 141, 142, and 144 of the first diaphragm 40, the convex part relatively located on the inner peripheral side protrudes larger in the axial direction than the convex part adjacent to the convex part. Specifically, the convex portion 141 projects in the axis O direction from the convex portion 142 (L3> L4), and the convex portion 142 projects from the convex portion 144 in the axis O direction (L4> L5). In the present embodiment, the convex portions 141, 142, 144 and the concave portions 143, 145 have the same thickness (film thickness).

  Thereby, the tensile distortion which arises in the convex part (protrusion part located in the inner peripheral side relatively) with a relatively small perimeter can be reduced. As a result, the durability of the first diaphragm 140 can be ensured even in the first diaphragm 140 in which three or more convex portions are formed concentrically.

  In addition, the ratio (L3 / L4, L4 / L5) of the axial direction length between adjacent convex parts is 1.1-5 similarly to the relationship of the ratio (L1 / L2) demonstrated in 1st Embodiment. Is preferred. This is to prevent the occurrence of cracks and abnormal noise while securing the amount of deformation of the first diaphragm 140.

  The convex portions 141, 142, and 144 have radii of curvature R 3, R 4 at the tips of the convex portions 141, 142, and 144 in the cross-sectional view (paper surface of FIG. 4) including the axis (axis O) of the second mounting member 3. R5 is set to the same value. Thereby, it can prevent that the distortion which arises in convex part 141,142,144 arises, and it can prevent that the load of a specific convex part becomes large. Therefore, the durability of the first diaphragm 140 can be improved.

  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 number of protrusions provided in the first diaphragms 40 and 140 (2 to 3 in the present embodiment) can be set as appropriate.

  In each of the above-described embodiments, the case where the convex portions 41, 42, 141, 142, and 144 (unevenness) are provided on the bottom surfaces of the first diaphragms 40 and 140 in the direction of the axis O has been described. However, the present invention is not necessarily limited thereto. . It is naturally possible to form the first diaphragms 40 and 140 into a bottomed cylindrical shape and to provide convex portions (unevenness) on both the bottom and side walls. By providing convex portions (concave / convex portions) not only at the bottom portion but also at the side wall portions, the amount of deformation of each convex portion due to pressure fluctuations in the liquid chamber can be reduced.

  In each of the above-described embodiments, the case where the third liquid chamber L3 and the second orifice 10a are formed by the liquid chamber forming member 10 has been described, but the liquid chamber forming member 10 is not necessarily required. When the liquid chamber forming member 10 is not provided, the periphery of the second diaphragm 30 is airtightly fixed to the partition 20 by means such as vulcanization adhesion. When the liquid chamber forming member 10 is not provided, the second diaphragm 30 and the vibration isolation base 4 constitute a chamber wall of the first liquid chamber L1.

DESCRIPTION OF SYMBOLS 1,101 Liquid enclosure type vibration isolator 2 1st attachment member 3 2nd attachment member 4 Anti-vibration base | substrate 20 Partition 20a Through-hole (air pipe line)
20b First orifice (orifice)
27 Wall part 30 2nd diaphragm 40,140 1st diaphragm 41,42,141,142,144 Convex part 45 Inner peripheral edge part
46 liquid sealing part 50,150 Pipe line forming member 50a Air pipe line
51 disc
52,152 shaft part 53 peripheral wall part (wall part)
54 Negative pressure introducing pipe 63 External pipe L Liquid enclosure chamber L1 First liquid chamber (liquid chamber)
L2 Second liquid chamber (liquid chamber)
R air chamber

Claims (5)

A first mounting member, a cylindrical second mounting member, a vibration isolating base that connects the second mounting member and the first mounting member and is formed of a rubber-like elastic body; and the second mounting member. A first diaphragm that is fixed and forms a liquid enclosure between the antivibration substrate, a partition that partitions the liquid enclosure into a plurality of liquid chambers, an orifice that communicates between the plurality of liquid chambers, and the anti-vibration A second diaphragm that is configured to be deformable by pressure fluctuations in the liquid chamber accompanying elastic deformation of the vibration base and forms an air chamber between the partition body, an air conduit that communicates with the air chamber, and In a liquid-filled vibration isolator comprising a negative pressure introduction pipe that is connected to an air pipe and connected to an external pipe that introduces a negative pressure or atmospheric pressure into the air chamber,
The air pipe is provided in a central portion in the radial direction of the first diaphragm and the partition through the first diaphragm and the partition,
The negative pressure introduction pipe is provided at a radial center of the first diaphragm,
The first diaphragm is formed in a bellows shape having concentric concavities and convexities around the negative pressure introduction tube when viewed from the axial direction of the second mounting member, and a plurality of protrusions projecting in the axial direction. Part
The plurality of convex portions, the convex portion located on the innermost peripheral side protrudes larger in the axial direction than the convex portion located on the outer peripheral side from the convex portion,
Includes a shaft portion to which the air line is penetrated formed through the first diaphragm, a conduit member having a disk portion which is protruded in a flange shape toward the said shaft portion radially outward,
The first diaphragm has an annular inner peripheral edge composed of a rubber-like elastic body in which the shaft portion is inserted on the inner peripheral side;
A liquid seal provided on the radially inner side of the inner peripheral edge,
The conduit forming member is pressed against the axial direction between the partition side of the inner peripheral edge portion and the disk portion and fixing the inner peripheral edge portion in a non-adhesive,
A wall portion that contacts the outer peripheral surface of the inner peripheral edge portion and restricts the movement of the inner peripheral edge portion radially outward ;
In a state in which the inner peripheral edge is compressed and deformed in the axial direction by the disk portion and the partition side, the outer peripheral surface of the inner peripheral edge is in contact with the wall portion, and the liquid seal portion is the shaft portion. while in contact with the outer peripheral surface of the hydraulic antivibration device according to claim Rukoto gap is provided between a portion and the shaft portion of the inner peripheral edge portion and the liquid sealing portion.   2. The liquid sealing according to claim 1, wherein the plurality of convex portions have a convex portion positioned relatively on the inner peripheral side projecting larger in the axial direction than a convex portion adjacent to the convex portion. Type vibration isolator.   The plurality of convex portions is the inner circumference of the convex portion located on the outer peripheral side of the convex portion, the sum of the axial dimension of the inner peripheral surface and the axial dimension of the outer peripheral surface of the convex portion located on the innermost peripheral side The liquid-filled vibration isolator according to claim 1 or 2, wherein the liquid-filled vibration isolator is larger than a sum of an axial dimension of the surface and an axial dimension of the outer peripheral surface.   The plurality of convex portions have a curvature radius of a tip of a convex portion adjacent to the convex portion in a cross-sectional view including an axis of the second mounting member. The liquid-filled vibration isolator according to any one of claims 1 to 3, wherein the liquid-filled vibration isolator is set to the same value as the radius.   The plurality of convex portions have a curvature radius of a tip of a convex portion adjacent to the convex portion in a cross-sectional view including an axis of the second mounting member. The liquid-filled vibration isolator according to any one of claims 1 to 3, wherein the liquid-filled vibration isolator is set to a value different from the radius.

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