JP2019203542A - Vibration isolation device - Google Patents

Abstract

To securely suppress abnormal noise caused by cavitation breaking without excessively decreasing inner diameters of pores.SOLUTION: A fluid encapsulated type vibration isolation device 10 includes a partition member 16 which partitions a fluid chamber 19 in a first attachment member 11 and encapsulating fluid L into a first fluid chamber 14 and a second fluid chamber 15, and a restriction passage 24 formed in the partition member so as to communicate the first fluid chamber and the second fluid chamber. The restriction passage includes a first communication part 26 opening to the first fluid chamber, a second communication part opening to the second fluid chamber, and a main body flow passage 25 communicating the first communication part and the second communication part. At least one of the first communication part and the second communication part includes a plurality of pores 26a, 26b penetrating the first barrier 38 facing the first fluid chamber or the second fluid chamber. The main body flow passage is provided with a barrier rigid body 41 with which liquid from the other of the first communication part and the second communication part is made to collide for diverging.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration isolator that is applied to, for example, automobiles, industrial machines, and the like and attenuates and absorbs vibration of a vibration generating unit such as an engine.

  Conventionally, a cylindrical first mounting member connected to one of the vibration generating portion and the vibration receiving portion, and a second mounting member connected to the other, and these both mounting members are elastically connected. An elastic body, and a partition member that partitions the liquid chamber in the first mounting member in which the liquid is sealed into a first liquid chamber and a second liquid chamber, and the partition member includes the first liquid chamber and the second liquid chamber. A restriction passage communicating with the liquid chamber is formed, and the restriction passage includes a first communication portion that opens to the first liquid chamber, a second communication portion that opens to the second liquid chamber, and a first communication portion and a second communication portion. There is known a liquid-encapsulated vibration isolator having a main body channel that communicates with each other.

As this type of vibration isolator, for example, as shown in Patent Document 1 below, one of the first communication portion and the second communication portion is a first liquid chamber or a first liquid chamber facing the second liquid chamber. A configuration having a plurality of pores penetrating the barrier is known.
In this vibration isolator, even if a large load (vibration) is input and the first liquid chamber or the second liquid chamber is suddenly reduced to a negative pressure, even if bubbles are generated in the main body flow path, By passing through a plurality of fine pores, it becomes possible to finely divide and disperse them in the first liquid chamber or the second liquid chamber, and to reduce the generated abnormal noise even if cavitation collapse occurs where bubbles collapse Can be suppressed.

International Publication No. 2016/027606

By the way, it is conceivable to further reduce the inner diameter of the pores in order to reliably suppress the abnormal noise caused by the collapse of cavitation.
However, in this case, there arises a new problem that it becomes difficult to manufacture the partition member.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration isolator capable of reliably suppressing abnormal noise caused by cavitation collapse without excessively reducing the inner diameter of the pores. And

In order to solve the above problems, the present invention proposes the following means.
A vibration isolator according to the present invention includes a cylindrical first mounting member coupled to one of a vibration generating unit and a vibration receiving unit, a second mounting member coupled to the other, and both the mounting members. An elastic body that elastically connects the liquid chamber, and a partition member that divides the liquid chamber in the first mounting member in which the liquid is sealed into a first liquid chamber and a second liquid chamber, and the partition member A liquid-filled vibration isolator having a restriction passage communicating the first liquid chamber and the second liquid chamber, wherein the restriction passage opens to the first liquid chamber. A second communication part that opens to the second liquid chamber, and a main body channel that communicates the first communication part and the second communication part, and includes the first communication part and the second communication part. At least one includes a plurality of pores penetrating the first barrier facing the first liquid chamber or the second liquid chamber, A serial body passage, wherein a barrier rigid to branch liquid was collision from any other side of said first communicating unit and the second communicating portion is provided.

According to the present invention, at the time of vibration input, both the attachment members are relatively displaced while elastically deforming the elastic body, the liquid pressure in the first liquid chamber and the second liquid chamber fluctuates, and the liquid passes through the restriction passage. An attempt is made to flow between the first liquid chamber and the second liquid chamber. At this time, the liquid flows into the restriction passage through one of the first communication portion and the second communication portion, passes through the main body flow path, and then passes through the other of the first communication portion and the second communication portion. Spill from.
Here, when the liquid flows into the first liquid chamber or the second liquid chamber from the restricting passage through the plurality of pores, each of the pores is caused to have a pressure loss by the first barrier in which these pores are formed. Since it circulates, the flow velocity of the liquid flowing into the first liquid chamber or the second liquid chamber can be suppressed. In addition, since the liquid flows through a plurality of pores instead of a single pore, it is possible to divide the liquid into a plurality of channels and reduce the flow rate of the liquid that has passed through the individual pores. Can do. Accordingly, even if a large load (vibration) is input to the vibration isolator, the liquid that has passed through the pores and has flowed into the first liquid chamber or the second liquid chamber, and the first liquid chamber or the second liquid chamber It is possible to suppress the difference in flow velocity generated between the liquid and the liquid and the generation of vortices due to the flow velocity difference and the generation of bubbles due to the vortices. Further, even if bubbles are generated not in the first liquid chamber or the second liquid chamber but in the restricted passage, the generated bubbles are caused to pass between the first liquid chamber or the second liquid by passing the liquid through the plurality of pores. It is possible to make the bubbles separate from each other in the liquid chamber, and it is possible to suppress the bubbles from joining and growing and to easily maintain the bubbles in a finely dispersed state.
As described above, the generation of bubbles itself can be suppressed, and even if bubbles are generated, the bubbles can be easily maintained in a finely dispersed state. However, it is possible to suppress the generated abnormal noise.

  In particular, since the barrier rigid body that causes the liquid from the other side of the first communication part and the second communication part to collide and branch is disposed in the main body flow path, the liquid from the other side is By causing the barrier rigid body to collide and branch before reaching the first barrier, it is possible to cause a pressure loss in the liquid. As a result, the flow velocity of the liquid from the other side can be reliably reduced before reaching the first barrier, and the difference caused by cavitation collapse can be achieved without excessively reducing the inner diameter of the pores. The sound can be reliably reduced.

  The barrier rigid body may be formed with a guide surface that joins the liquid from the other side that has been branched due to collision and guides the liquid to the first barrier.

  In this case, since the guide surface is formed on the barrier rigid body, the liquid from the other side collides with the barrier rigid body and branches, and then is merged by the guide surface, so that the branched liquids collide with each other, Pressure loss will occur. Therefore, by allowing the liquid from the other side to pass through the rigid barrier, the flow rate of the liquid can be more reliably reduced before reaching the first barrier.

  The barrier rigid body faces the first barrier in the opening direction of the pores, and among the plurality of pores, the flow resistance of the pores facing the barrier rigid body in the opening direction of the pores is: It may be larger than the flow resistance of the remaining pores.

  In this case, the barrier rigid body is opposed to the pore in the opening direction, and the flow resistance of the pore through which the liquid having a relatively large flow rate flows through the barrier rigid body is merged. Since the flow resistance of the pores into which the liquid with a relatively small flow rate flows is larger, the liquid from the other side is opposed to the plurality of pores in the opening direction of the barrier rigid body and the pores. It can be made to flow evenly regardless of whether or not it is.

  The barrier rigid body is opposed to the first barrier in the opening direction of the pores, and is opposed to the barrier rigid body in the opening direction of the pores on the inner surface of the first barrier facing the main body channel. The ratio of the opening area of the pores to the flat area of the portion may be smaller than the ratio of the opening area of the pores to the flat area of the remaining portion.

  In this case, on the inner surface of the first barrier, the pores are opposed to the barrier rigid body in the opening direction of the pores, merge through the barrier rigid body, and occupy the plane area of the portion where the liquid with a relatively large flow rate is guided. The ratio of the opening area of the pore is not opposite to the barrier rigid body in the opening direction of the pores, and is smaller than the ratio of the opening area of the pores to the plane area of the portion where the liquid having a relatively small flow rate is guided. The liquid from the side can be allowed to flow uniformly into the plurality of pores with little deviation regardless of whether or not the barrier rigid body and the pores are opposed to each other in the opening direction.

  According to the present invention, even if the inner diameter of the pores is not excessively reduced, it is possible to reliably suppress abnormal noise caused by cavitation collapse.

It is a longitudinal cross-sectional view of the vibration isolator which concerns on one Embodiment of this invention. It is a top view of the partition member which comprises the vibration isolator shown in FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. It is a top view of the partition member which comprises the vibration isolator which concerns on the modification of this invention.

Hereinafter, an embodiment of a vibration isolator according to the present invention will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, the vibration isolator 10 includes a cylindrical first mounting member 11 connected to one of the vibration generating unit and the vibration receiving unit, and a second mounting member 12 connected to the other, An elastic body 13 that elastically connects the first mounting member 11 and the second mounting member 12 to each other, and a liquid chamber 19 in the first mounting member 11 in which the liquid L is sealed are a main liquid chamber (first liquid chamber) described later. ) 14 and a partition member 16 that divides into a secondary liquid chamber (second liquid chamber) 15.

Hereinafter, the direction along the central axis O of the first mounting member 11 is referred to as an axial direction. Further, the second mounting member 12 side along the axial direction is referred to as an upper side, and the partition member 16 side is referred to as a lower side. Further, in a plan view of the vibration isolator 10 viewed from the axial direction, a direction intersecting the central axis O is referred to as a radial direction, and a direction around the central axis O is referred to as a circumferential direction.
The first mounting member 11, the second mounting member 12, and the elastic body 13 are each formed in a circular shape or an annular shape in a plan view, and are disposed coaxially with the central axis O.

  When the vibration isolator 10 is mounted on, for example, an automobile, the second mounting member 12 is connected to an engine as a vibration generating unit, and the first mounting member 11 is connected to a vehicle body as a vibration receiving unit. This suppresses transmission of engine vibration to the vehicle body. In addition, the 1st attachment member 11 may be connected with a vibration generation part, and the 2nd attachment member 12 may be connected with a vibration receiving part.

  The second mounting member 12 is a columnar member extending in the axial direction, and is formed in a hemispherical shape whose lower end bulges downward. In the second mounting member 12, a flange 12 a that protrudes outward in the radial direction is formed at a portion located above the lower end portion of the hemispherical shape. A screw hole 12b extending downward from the upper end surface of the second mounting member 12 is formed, and a bolt (not shown) serving as an engine-side mounting tool is screwed into the screw hole 12b. The second mounting member 12 is disposed in the upper end opening of the first mounting member 11 via the elastic body 13.

  The elastic body 13 is a rubber body that is vulcanized and bonded to the inner peripheral surface of the upper portion of the first mounting member 11 and the outer peripheral surface of the lower portion of the second mounting member 12, respectively, and interposed therebetween. The upper end opening of the first mounting member 11 is closed from above. A first rubber film 13 a that covers the lower surface, outer peripheral surface, and upper surface of the flange portion 12 a is integrally formed on the upper end portion of the elastic body 13. A second rubber film 13 b that covers the inner peripheral surface of the first mounting member 11 in a liquid-tight manner is integrally formed at the lower end of the elastic body 13. As the elastic body 13, an elastic body made of synthetic resin or the like can be used in addition to rubber.

The first attachment member 11 is formed in a cylindrical shape, and is connected to a vehicle body or the like as a vibration receiving portion via a bracket (not shown). The lower end opening of the first mounting member 11 is closed by the diaphragm 20.
The diaphragm 20 is made of an elastic material such as rubber or soft resin, and has a bottomed cylindrical shape. The outer peripheral surface of the diaphragm 20 is vulcanized and bonded to the inner peripheral surface of the diaphragm ring 21. The diaphragm ring 21 is fitted in the lower end portion of the first mounting member 11 via the second rubber film 13b. The diaphragm ring 21 is swaged and fixed in the lower end portion of the first mounting member 11. The upper end opening edge of each of the diaphragm 20 and the diaphragm ring 21 is in liquid-tight contact with the lower surface of the partition member 16.

And since the diaphragm 20 was attached to the 1st attachment member 11 in this way, the inside of the 1st attachment member 11 becomes the liquid chamber 19 sealed with the elastic body 13 and the diaphragm 20 liquid-tightly. . The liquid chamber 19 is filled (filled) with the liquid L.
In the illustrated example, the bottom portion of the diaphragm 20 has a shape that is deep on the outer peripheral side and shallow at the center. However, as the shape of the diaphragm 20, various conventionally known shapes can be adopted in addition to such a shape.

  The liquid chamber 19 is divided into a main liquid chamber 14 and a sub liquid chamber 15 by a partition member 16. The main liquid chamber 14 has the lower surface 13c of the elastic body 13 as a part of the wall surface, and the second rubber film 13b and the partition member 16 that cover the elastic body 13 and the inner peripheral surface of the first mounting member 11 in a liquid-tight manner. It is an enclosed space, and the internal volume changes due to the deformation of the elastic body 13. The auxiliary liquid chamber 15 is a space surrounded by the diaphragm 20 and the partition member 16, and the internal volume changes due to the deformation of the diaphragm 20. The vibration isolator 10 having such a configuration is a compression-type device that is attached and used so that the main liquid chamber 14 is positioned on the upper side in the vertical direction and the auxiliary liquid chamber 15 is positioned on the lower side in the vertical direction. .

  The partition member 16 is provided with a restriction passage 24 that allows the main liquid chamber 14 and the sub liquid chamber 15 to communicate with each other. The restriction passage 24 is tuned so that resonance (liquid column resonance) occurs when, for example, a shake vibration having a frequency of around 10 Hz is input to the vibration isolator 10. As shown in FIG. 2, the restriction passage 24 includes a first communication portion 26 that opens to the main liquid chamber 14, a second communication portion 27 that opens to the auxiliary liquid chamber 15, and the first communication portion 26 and the second communication portion. 27 is provided with a main body flow path 25 communicating with 27.

The main body channel 25 includes a main channel 31 extending from one of the first communication unit 26 and the second communication unit 27 toward one side in the circumferential direction, and one end in the circumferential direction of the main channel 31. And an end chamber 34 projecting radially inward from the portion.
In the illustrated example, the main flow path 31 extends from the second communication portion 27 toward one side in the circumferential direction. The end chamber 34 and the first communication portion 26 are directly connected in the axial direction, and the end chamber 34 is an end portion of the main body flow path 25 on the first communication portion 26 side.

  The main flow path 31 is formed on the outer peripheral surface of the partition member 16. The main flow path 31 is disposed in the partition member 16 in an angle range of less than 360 ° with the central axis O as the center. In the illustrated example, the main flow path 31 is disposed in the partition member 16 in an angle range exceeding 180 ° with the central axis O as the center.

The main channel 31 is disposed coaxially with the central axis O, and is disposed on the lower side of the annular upper barrier 35 that is positioned on the upper side and the front and rear surfaces face the axial direction, and coaxial with the central axis O. The upper surface of the annular lower barrier 36 whose front and back surfaces are directed in the axial direction and the groove bottom surface 37 that connects the inner peripheral edges of the upper barrier 35 and the lower barrier 36 and faces radially outward are defined. Yes.
The upper barrier 35 faces the main liquid chamber 14. The lower barrier 36 faces the secondary liquid chamber 15, and the second communication portion 27 is configured by one opening that penetrates the lower barrier 36 in the axial direction.

The end chamber 34 has a circular shape in a plan view as viewed from the axial direction, and the central axis of the end chamber 34 extends in the axial direction. The end chamber 34 is disposed at a position away from the central axis O. Hereinafter, in the plan view, a direction intersecting with the central axis of the end chamber 34 is referred to as an end chamber radial direction, and a direction around the central axis of the end chamber 34 is referred to as an end chamber circumferential direction.
The outer communication portion 46 that connects the end chamber 34 and the main channel 31 extends linearly in the plan view. The outer communication portion 46 extends in the tangential direction of the inner peripheral surface of the end chamber 34 in the plan view. The size of the outer communication portion 46 in the circumferential direction is smaller than the inner diameter of the end chamber 34. The end chamber 34 projects to the other side in the circumferential direction of the main flow path 31 with respect to the outer communication portion 46. The sizes of the outer communication portion 46 and the end chamber 34 in the axial direction are equal to each other.

  Of the wall surfaces defining the end chamber 34, the upper wall surface positioned on the upper side and facing downward is the lower surface of the first barrier 38 whose upper surface faces the main liquid chamber 14, and is positioned on the lower side and facing upward. The lower wall surface is the upper surface of the second barrier 39 whose lower surface faces the auxiliary liquid chamber 15. The lower surface of the first barrier 38 and the upper surface of the second barrier 39 are flat surfaces extending in a direction orthogonal to the axial direction. The first barrier 38 and the second barrier 39 are in the shape of a disc disposed coaxially with the central axis of the end chamber 34.

  The first communication portion 26 includes a plurality of pores 26 a and 26 b that penetrate the first barrier 38 that faces the main liquid chamber 14. The pores 26a and 26b penetrate the first barrier 38 in the axial direction. That is, the opening direction of the pores 26a and 26b coincides with the axial direction, and is orthogonal to the extending direction R of the main body channel 25 from the second communication portion 27 side to the first communication portion 26 side. ing. The pores 26 a and 26 b may be formed in the lower barrier 36 facing the sub liquid chamber 15 and provided in the second communication portion 27. The opening direction of the pores 26a and 26b may be a direction inclined with respect to the extending direction R of the main body flow path 25 and the axial direction.

As shown in FIG. 3, the flow path lengths of the plurality of pores 26a and 26b are equal to each other. The inner diameters of the pores 26a and 26b are the same over the entire length. Each of the plurality of pores 26a and 26b is smaller than the channel cross-sectional area of the main channel 31, and is disposed inside the end chamber 34 in a plan view viewed from the axial direction.
The sum total of the channel cross-sectional areas in each of the plurality of pores 26a and 26b may be, for example, 1.5 times to 4.0 times the minimum value of the channel cross-sectional area of the main channel 31. In the illustrated example, the channel cross-sectional area of the main channel 31 is the same over the entire length. The cross-sectional area of the pores 26a and 26b may be, for example, 25 mm ² or less, preferably 0.7 mm ² or more and 17 mm ² or less.

  An upper barrier 35 and a first barrier 38 defining a restriction passage 24 and facing the main liquid chamber 14; a lower barrier 36 defining a restriction passage 24 and facing the sub-liquid chamber 15; and Of the second barrier 39, the thickness of the first barrier 38 in which the plurality of pores 26 a and 26 b are formed is greater than the thickness of the upper barrier 35, the lower barrier 36, and the second barrier 39. The thickness of the first barrier 38 in which the plurality of pores 26a and 26b are located is the same over the entire region. The upper and lower surfaces of the first barrier 38 are flat surfaces extending in a direction orthogonal to the axial direction.

In the present embodiment, the main body flow path 25 is provided with a barrier rigid body 41 that causes the liquid L from either the first communication portion 26 or the second communication portion 27 to collide and branch. .
In the illustrated example, the barrier rigid body 41 causes the liquid L from the second communication portion 27 side to collide and branch. The barrier rigid body 41 is disposed in the end chamber 34 of the main body flow path 25. The barrier rigid body 41 is opposed to the first barrier 38 in the axial direction. As shown in FIG. 3, the barrier rigid body 41 is integrally formed by abutting the bottom surfaces of two conical bodies whose diameters are gradually reduced from the inner side toward the outer side in the axial direction, and in the end chamber radial direction. It is the structure which exhibits a rhombus shape seeing from the outside. The barrier rigid body 41 is disposed coaxially with the central axis of the end chamber 34. The surface of the barrier rigid body 41 is not in contact with the wall surface defining the end chamber 34. In the plan view, the ratio of the flat area of the barrier rigid body 41 to the end chamber 34 is about half. The barrier rigid body 41 is a rigid body that is not deformed or displaced by the flow pressure of the liquid L flowing through the restriction passage 24.
In addition, for example, the barrier rigid body 41 may have a configuration in which the bottom surfaces of two pyramidal bodies are abutted to be integrated and have a rhombus shape when viewed from the outside in the radial direction, a columnar shape, a plate shape, or the like.

  Among the surfaces of the barrier rigid body 41, the surface that gradually extends inward in the end chamber radial direction from the central portion in the axial direction causes the liquid L from the second communication portion 27 side to pass from below the barrier rigid body 41. The branch surface 41a is branched by colliding. Among the surfaces of the barrier rigid body 41, the surface extending toward the inner side in the end chamber radial direction gradually increases from the central portion in the axial direction to join the liquid L branched by the branch surface 41 a to make the barrier rigid body 41. A guide surface 41 b that passes upward and guides the first barrier 38 is formed. The inclination angles of the branch surface 41a and the guide surface 41b with respect to the central axis of the end chamber 34 are equal to each other.

  A connecting piece 43 that fixes the barrier rigid body 41 to the wall surface of the end chamber 34 is disposed on the surface of the barrier rigid body 41. A plurality of the connecting pieces 43 are arranged on the surface of the barrier rigid body 41 with an interval in the circumferential direction of the end chamber. The connecting piece 43 fixes the barrier rigid body 41 to an inner peripheral surface facing the inner side in the end chamber radial direction among the wall surfaces defining the end chamber 34. The connecting piece 43 is disposed at the central portion of the barrier rigid body 41 in the axial direction. The sum of the sizes in the end chamber circumferential direction of the plurality of connecting pieces 43 is smaller than the sum of the sizes in the end chamber circumferential direction of the portion where the connecting pieces 43 are not disposed in the central portion of the barrier rigid body 41 in the axial direction. . The barrier rigid body 41 faces the outer communication portion 46 without the connection piece 43 interposed therebetween.

  Among the plurality of pores 26a and 26b, the flow resistance of the pore 26a (hereinafter referred to as opposed pore) 26a that is opposed to the barrier rigid body 41 in the axial direction is small and does not face the remaining barrier rigid body 41 in the axial direction. It is larger than the flow resistance of the holes (hereinafter referred to as non-opposing pores) 26b.

  In the illustrated example, the non-opposing pores 26b are opposed to the lower wall surface of the end chamber 34 (the inner surface of the main body flow path 25) in the axial direction without the barrier rigid body 41 interposed therebetween. The non-facing pores 26b are disposed in the outer peripheral portion of the first barrier 38, and the opposing pores 26a are disposed in the central portion of the first barrier 38 that is located radially inward from the outer peripheral portion. The inner diameter of the opposed pore 26a is smaller than the inner diameter of the non-opposed pore 26b. The channel lengths of the opposed pore 26a and the non-opposed pore 26b are equal to each other. The plurality of opposed pores 26a have the same shape and the same size. The plurality of non-opposing pores 26b have the same shape and the same size.

  The channel length of the opposed pore 26a may be longer than the channel length of the non-opposed pore 26b, and the inner peripheral surface of the non-opposed pore 26b is made smooth, while the opposed pore An uneven portion may be formed on the inner peripheral surface of 26a. In addition, by appropriately adjusting at least one of the inner diameter, the flow path length, etc., the flow resistance of the opposed pore 26a can be reduced. It may be larger than the distribution resistance.

  Here, the partition member 16 is configured by an upper member 47, an intermediate member 42, and a lower member 48 being stacked in the axial direction. Each of the upper member 47, the intermediate member 42, and the lower member 48 is formed in a plate shape whose front and back surfaces face the axial direction. The upper member 47 and the lower member 48 are each formed in a disk shape that is disposed coaxially with the central axis O. Note that the partition member 16 may be integrally formed as a whole.

The outer peripheral surface of the upper member 47 and the second arc portion 42a described later of the intermediate member 42 serve as the groove bottom surface 37. A first recess is formed on the lower surface of the upper member 47, and a second recess is formed on the upper surface of the lower member 48 at a position facing the first recess. An end chamber 34 is defined by the inner surfaces of the first recess and the second recess. The first communication portion 26 is formed in a portion of the upper member 47 where the first recess is located, and this portion serves as the first barrier 38. A portion of the lower member 48 where the second recess is located is a second barrier 39.
On the outer peripheral surface of the upper end portion of the lower member 48, an annular lower barrier 36 is formed that protrudes outward in the radial direction and in which the second communication portion 27 is formed. On the outer peripheral surface of the upper end portion of the upper member 47, an upper barrier 35 that protrudes outward in the radial direction and faces the lower barrier 36 of the lower member 48 in the axial direction is formed.

  The intermediate member 42 is disposed between the lower surface of the upper member 47 and the upper surface of the lower member 48. The outer peripheral surface of the intermediate member 42 has a second arc portion 42a that forms part of the groove bottom surface 37 in the plan view, and a second chord portion that connects both ends of the second arc portion 42a and extends linearly. 42b. The intermediate member 42 is formed with a semicircular opening 42c that opens to the second chord portion 42b in the plan view. The inner peripheral surface of the opening 42c is a part of the inner peripheral surface of the end chamber 34. There is no. The barrier rigid body 41 is connected to the inner peripheral surface of the opening 42c through a connecting piece 43. The front and back surfaces of the connecting piece 43 are flush with the front and back surfaces of the intermediate member 42. The connecting piece 43 and the barrier rigid body 41 are formed integrally with the intermediate member 42.

  In the vibration isolator 10 having such a configuration, both attachment members 11 and 12 are relatively displaced while elastically deforming the elastic body 13 at the time of vibration input. Then, the liquid pressure in the main liquid chamber 14 fluctuates, the liquid L in the main liquid chamber 14 flows into the sub liquid chamber 15 through the restriction passage 24, and the liquid L in the sub liquid chamber 15 flows into the restriction passage 24. Through the main liquid chamber 14.

  As described above, according to the vibration isolator 10 according to the present embodiment, when the liquid L flows into the main liquid chamber 14 from the restriction passage 24 through the plurality of pores 26a and 26b, these pores 26a. , 26b is circulated through each of the pores 26a, 26b while being subjected to pressure loss by the first barrier 38 formed with the first barrier 38, so that the flow velocity of the liquid L flowing into the main liquid chamber 14 can be suppressed. In addition, since the liquid L flows through the plurality of pores 26a and 26b instead of the single pores 26a and 26b, the liquid L can be branched and distributed, and the individual pores 26a, 26b, The flow rate of the liquid L that has passed through 26b can be reduced. Thus, even if a large load (vibration) is input to the vibration isolator 10, the liquid L that has flowed into the main liquid chamber 14 through the pores 26a and 26b, and the liquid L in the main liquid chamber 14 It is possible to suppress the flow velocity difference generated between the two vortices, and the generation of vortices due to the flow velocity difference and the generation of bubbles due to the vortices can be suppressed.

Even if bubbles are generated in the restriction passage 24 instead of the main liquid chamber 14, the generated bubbles are separated from each other in the main liquid chamber 14 by passing the liquid L through the plurality of pores 26 a and 26 b. It is possible to prevent the bubbles from joining and growing, and to easily maintain the bubbles in a finely dispersed state.
As described above, the generation of bubbles itself can be suppressed, and even if bubbles are generated, the bubbles can be easily maintained in a finely dispersed state. However, it is possible to suppress the generated abnormal noise.

  In particular, the barrier rigid body 41 for allowing the liquid L from the second communication portion 27 side to collide and branch in the main body flow path 25 is disposed, so that the liquid L from the second communication portion 27 side is allowed to flow to the first barrier. By causing the barrier rigid body 41 to collide and branch before reaching 38, a pressure loss can be caused in the liquid L. As a result, the flow velocity of the liquid L from the second communication portion 27 side can be reliably reduced before reaching the first barrier 38, and the inner diameters of the pores 26a and 26b can be reduced excessively. However, it is possible to reliably suppress the abnormal noise caused by the collapse of cavitation.

  In addition, since the guide surface 41b is formed on the barrier rigid body 41, the liquid L from the second communication portion 27 side collides with the barrier rigid body 41 and branches, and then is merged by the guide surface 41b. The liquids L collided with each other, resulting in a pressure loss. Accordingly, by allowing the liquid L from the second communication portion 27 side to pass through the barrier rigid body 41, the flow rate of the liquid L can be more reliably reduced before reaching the first barrier 38.

  Further, the flow resistance of the opposed pores 26a that are opposed to the barrier rigid body 41 in the axial direction and merge through the barrier rigid body 41 and into which the liquid L having a relatively large flow rate flows flows in the axial direction of the barrier rigid body 41. Since the flow resistance of the non-opposing pore 26b into which the liquid L having a relatively small flow rate does not face is larger, the liquid L from the second communication portion 27 side is blocked by the plurality of pores 26a and 26b. Regardless of whether or not it is opposed to the rigid body 41 in the axial direction, it can flow evenly with little deviation.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the barrier rigid body 41 is disposed in the end chamber 34 of the main body flow path 25. However, the barrier rigid body 41 may be disposed in the main flow path 31 or the external communication portion 46. The liquid L from the 26th side may be caused to collide and be branched.
Moreover, you may employ | adopt the structure which both the 1st communication part 26 and the 2nd communication part 27 have the pores 26a and 26b.
Moreover, although the structure which makes the partition member 16 1 round as the main flow path 31 was shown, the structure which circulates the partition member 16 longer than 1 round may be employ | adopted.
Further, as the main body channel 25, for example, a configuration extending in the axial direction or a configuration without the end chamber 34 may be employed.

In the above embodiment, the flow resistance of the opposed pores 26a is made larger than the flow resistance of the non-opposed pores 26b. However, the present invention is not limited to this, for example, as shown in FIG. The ratio of the opening area of the opposed pores 26a in the plane area of the portion facing the barrier rigid body 41 in the axial direction is opposed to the remaining barrier rigid body 41 in the axial direction. You may make it smaller than the ratio of the opening area of the non-opposing pore 26b which occupies the flat area of the part which is not.
In the illustrated example, the non-opposing pores 26 b are opposed to the lower wall surface of the end chamber 34 in the axial direction without the barrier rigid body 41 interposed therebetween. The inner diameters of the opposed pore 26a and the non-opposed pore 26b are equal to each other.

  In this case, on the lower surface of the first barrier 38, it is opposed to the barrier rigid body 41 in the axial direction, passes through the barrier rigid body 41, merges, and occupies the plane area of the portion where the liquid L having a relatively large flow rate is guided. The ratio of the opening area of the pores 26a is not opposite to the barrier rigid body 41 in the axial direction, and the ratio of the opening area of the non-facing pores 26b occupying the plane area of the portion where the liquid L having a relatively small flow rate is guided. Since it is small, the liquid L from the second communication portion 27 side can be made to flow uniformly into the plurality of pores 26a and 26b with little deviation regardless of whether or not the barrier rigid body 41 is opposed in the axial direction. .

  Further, after the flow resistance of the opposed pore 26a is made larger than the flow resistance of the non-opposed pore 26b, as shown in FIG. 4, the lower surface of the first barrier 38 is opposed to the barrier rigid body 41 in the axial direction. The ratio of the opening area of the opposed pore 26a to the flat area of the portion is made smaller than the ratio of the opening area of the non-opposing pore 26b to the remaining flat area of the portion not facing the barrier rigid body 41 in the axial direction. May be.

In the above embodiment, the guide surface 41b is formed on the barrier rigid body 41. However, the barrier rigid body 41 that does not have the guide surface 41b may be adopted.
In this case, the liquid L from the second communication portion 27 side is less likely to reach the opposed pore 26a than the non-opposed pore 26b, and therefore the flow resistance of the opposed pore 26a is reduced to the flow resistance of the non-opposed pore 26b. Further, the ratio of the opening area of the opposed pores 26a occupying the plane area of the portion facing the barrier rigid body 41 in the axial direction on the lower surface of the first barrier 38 may be the same as that of the remaining barrier rigid body 41. You may make it larger than the ratio of the opening area of the non-opposing pore 26b which occupies the flat area of the part which is not facing in an axial direction.
The barrier rigid body 41 may be close to the lower surface of the first barrier 38 and spaced upward from the upper surface of the second barrier 39.
In this case, most of the liquid flowing into the end chamber 34 from the main flow path 31 can collide with the barrier rigid body 41 before reaching the first barrier 38, and the generated pressure loss is more reliably increased. Can do.

  Moreover, in the said embodiment, although the compression type vibration isolator 10 which a positive pressure acts on the main liquid chamber 14 by the support load acting was demonstrated, the main liquid chamber 14 is located in the vertical lower side, and The auxiliary liquid chamber 15 is mounted so as to be positioned on the upper side in the vertical direction, and can be applied to a suspension type vibration isolator in which a negative pressure is applied to the main liquid chamber 14 when a support load is applied.

  In the above embodiment, the partition member 16 partitions the liquid chamber 19 in the first mounting member 11 into the main liquid chamber 14 having the elastic body 13 as a part of the wall surface and the sub liquid chamber 15. It is not limited to this. For example, instead of providing the diaphragm 20, a pair of elastic bodies 13 may be provided in the axial direction, and instead of providing the auxiliary liquid chamber 15, a pressure receiving liquid chamber having the elastic body 13 at a part of the wall surface may be provided. Good. For example, the partition member 16 partitions the liquid chamber 19 in the first mounting member 11 in which the liquid L is sealed into the first liquid chamber 14 and the second liquid chamber 15, and the first liquid chamber 14 and the second liquid chamber 15. At least one of the two liquid chambers can be appropriately changed to another configuration having the elastic body 13 in a part of the wall surface.

  The vibration isolator 10 according to the present invention is not limited to an engine mount of a vehicle, and can be applied to other than the engine mount. For example, the present invention can be applied to a mount of a generator mounted on a construction machine, or can be applied to a mount of a machine installed in a factory or the like.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

DESCRIPTION OF SYMBOLS 10 Vibration isolator 11 1st attachment member 12 2nd attachment member 13 Elastic body 14 Main liquid chamber (1st liquid chamber)
15 Secondary liquid chamber (second liquid chamber)
16 Partition member 19 Liquid chamber 24 Restriction passage 25 Main body flow path 26 1st communication part 26a, 26b Fine hole 27 2nd communication part 38 1st barrier 41 Barrier rigid body 41b Guide surface L Liquid O Center axis

Claims (4)

A cylindrical first mounting member coupled to one of the vibration generating unit and the vibration receiving unit, and a second mounting member coupled to the other;
An elastic body that elastically connects both the mounting members;
A partition member that divides the liquid chamber in the first mounting member in which the liquid is sealed into a first liquid chamber and a second liquid chamber, and
A liquid-sealed vibration isolator in which a restriction passage communicating the first liquid chamber and the second liquid chamber is formed in the partition member,
The restriction passage includes a first communication portion that opens to the first liquid chamber, a second communication portion that opens to the second liquid chamber, and a main body channel that communicates the first communication portion and the second communication portion. With
At least one of the first communication portion and the second communication portion includes a plurality of pores penetrating the first barrier facing the first liquid chamber or the second liquid chamber,
An anti-vibration device according to claim 1, wherein a barrier rigid body is provided in the main body flow path to cause a liquid from one of the first communication portion and the second communication portion to collide and branch.   The anti-vibration device according to claim 1, wherein a guide surface for guiding the liquid to the first barrier by joining the liquid from the other side that collides and branches is formed in the barrier rigid body. The barrier rigid body is opposed to the first barrier in the opening direction of the pores,
3. The prevention according to claim 2, wherein among the plurality of pores, the flow resistance of the pores facing the barrier rigid body in the opening direction of the pores is larger than the flow resistance of the remaining pores. Shaker. The barrier rigid body is opposed to the first barrier in the opening direction of the pores,
On the inner surface of the first barrier facing the main body flow channel side, the ratio of the opening area of the pores to the flat area of the portion facing the barrier rigid body in the opening direction of the pores is the flat area of the remaining portion. The vibration isolator according to claim 2 or 3, wherein the vibration isolator is smaller than a ratio of an opening area of the pores.

Images