JP6986489B2 - Anti-vibration device - Google Patents

Description

The present invention relates to a vibration isolator that is applied to, for example, an automobile, an industrial machine, or the like, and attenuates and absorbs vibration of a vibration generating portion of an engine or the like.

Conventionally, a tubular first mounting member connected to either one of a vibration generating portion and a vibration receiving portion, and a second mounting member connected to the other, and both mounting members are elastically connected. It is provided with an elastic body and a partition member for partitioning the liquid chamber in the first mounting member in which the liquid is sealed into the first liquid chamber and the second liquid chamber, and the partition member includes the first liquid chamber and the second liquid chamber. A restricted passage that communicates with the liquid chamber is formed, and the restricted passage has 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. A liquid-filled type anti-vibration device having a main body flow path that communicates with is known.

As a vibration isolator of this type, for example, as shown in Patent Document 1 below, one of the first communication section and the second communication section faces the first liquid chamber or the second liquid chamber. A configuration with a plurality of pores penetrating a barrier is known.
In this vibration isolator, even if bubbles are generated in the main body flow path when a large load (vibration) is input and the first liquid chamber or the second liquid chamber is suddenly negatively pressured, these bubbles are generated. By passing through a plurality of pores, it becomes possible to divide it into small pieces and disperse it in the first liquid chamber or the second liquid chamber, and even if cavitation collapse occurs in which bubbles collapse, the abnormal noise generated is reduced. It can be suppressed.

International Publication No. 2016/027606

By the way, in order to surely suppress the abnormal noise caused by the cavitation collapse, it is conceivable to further reduce the inner diameter of the pores.
However, in this case, a new problem arises in which 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 surely suppressing abnormal noise caused by cavitation collapse without making the inner diameter of pores excessively small. And.

In order to solve the above problems, the present invention proposes the following means.
The vibration isolator according to the present invention includes a tubular first mounting member connected to either one of a vibration generating portion and a vibration receiving portion, a second mounting member connected to the other, and both mounting members. The partition member is provided with an elastic body for elastically connecting the liquids and a partition member for partitioning the liquid chamber in the first mounting member in which the liquid is sealed into the first liquid chamber and the second liquid chamber. , A liquid-filled type anti-vibration device in which a limiting passage connecting the first liquid chamber and the second liquid chamber is formed, and the limiting passage is a first communication portion opening to the first liquid chamber. A second communication section that opens into the second liquid chamber, and a main body flow path that communicates the first communication section with the second communication section, and is one of the first communication section and the second communication section. At least one of the first communication portion and the second communication portion has a plurality of pores penetrating the first barrier facing the first liquid chamber or the second liquid chamber, and the main body flow path has the first communication portion and the second communication portion. It is characterized in that a barrier rigid body is disposed in which a liquid from either other side is collided and branched.

According to the present invention, at the time of vibration input, both mounting members are relatively displaced while elastically deforming the elastic body, the hydraulic pressures of the first liquid chamber and the second liquid chamber fluctuate, and the liquid passes through the limiting passage. Attempts to circulate between the first liquid chamber and the second liquid chamber. At this time, the liquid flows into the restricted 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. Outflow from.
Here, when the liquid flows into the first liquid chamber or the second liquid chamber from the limiting passage through the plurality of pores, each pore is pressure-lossed by the first barrier in which these pores are formed. Since it is circulated, the flow velocity of the liquid flowing into the first liquid chamber or the second liquid chamber can be suppressed. Moreover, since the liquid flows through a plurality of pores instead of a single pore, the liquid can be branched and circulated in a plurality of pores, and the flow velocity of the liquid passing through the individual pores can be reduced. Can be done. As a result, 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 liquid that 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 between the liquid and the liquid, and it is possible to suppress the generation of vortices due to the difference in flow velocity and the generation of bubbles due to this vortex. Further, even if bubbles are generated in the restricted passage instead of the first liquid chamber or the second liquid chamber, the generated bubbles are transferred to each other in the first liquid chamber or the second liquid chamber by passing the liquid through a plurality of pores. It becomes possible to separate the bubbles in the liquid chamber, and it is possible to suppress the merging and growth of bubbles and facilitate the maintenance of the bubbles in a finely dispersed state.
As described above, it is possible to suppress the generation of bubbles themselves, and even if bubbles are generated, it is possible to easily maintain the state in which the bubbles are finely dispersed, so that cavitation collapse occurs in which the bubbles collapse. However, the generated abnormal noise can be suppressed to a small level.

In particular, since a barrier rigid body is provided in the main body flow path so that the liquid from either the first communication portion or the second communication portion collides with the liquid from the other side to branch, so that the liquid from the other side can be used. By colliding with the barrier rigid body and branching it before reaching the first barrier, a pressure loss can be caused in the liquid. This makes it possible to reliably reduce the flow velocity of the liquid from the other side before reaching the first barrier, and even if the inner diameter of the pores is not made excessively small, the difference caused by the cavitation collapse The sound can be surely suppressed to a low level.

Further, the barrier rigid body may be formed with a guide surface that guides the liquid from the other side that has collided and branched 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 the liquids are merged by the guide surface, so that the branched liquids collide with each other. Pressure loss will occur. Therefore, by passing the liquid from the other side through the barrier rigid body, the flow velocity of the liquid can be reduced more reliably before reaching the first barrier.

Further, 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 determined. It may be larger than the flow resistance of the remaining pores.

In this case, the flow resistance of the pores facing the barrier rigid body in the opening direction of the pores, passing through the barrier rigid body and merging, and into which a liquid having a relatively large flow rate flows in, is the opening direction of the barrier rigid body and the pores. Since it is not opposed to each other and is larger than the flow resistance of the pore into which the liquid having a relatively small flow rate flows in, the liquid from the other side is opposed to the plurality of pores in the opening direction of the barrier rigid body. Regardless of whether it is present or not, it can be flowed evenly with little bias.

Further, the barrier rigid body faces the first barrier in the opening direction of the pores, and faces the barrier rigid body in the opening direction of the pores on the inner surface of the first barrier facing the main body flow path side. 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 that face the barrier rigid body in the opening direction of the pores, pass through the barrier rigid body, merge, and occupy the flat area of the portion where the liquid having a relatively large flow rate is guided. Since the ratio of the opening area of the barrier rigid body does not face 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 flat area of the portion where the liquid having a relatively small flow rate is guided, the other The liquid from the side can flow into the plurality of pores evenly with little bias regardless of whether or not the barrier rigid body and the pores face each other in the opening direction.

According to the present invention, abnormal noise caused by cavitation collapse can be reliably suppressed without making the inner diameter of the pores excessively small.

It is a vertical sectional view of the vibration isolation device which concerns on one Embodiment of this invention. It is a top view of the partition member constituting the vibration isolation device shown in FIG. 1. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is a top view of the partition member constituting the vibration isolation device which concerns on the modification of this invention.

Hereinafter, embodiments of the 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 tubular first mounting member 11 connected to either a vibration generating portion or a vibration receiving portion, and a second mounting member 12 connected to the other. A main liquid chamber (first liquid chamber), which will be described later, is a liquid chamber 19 in the first mounting member 11 in which a liquid L is sealed and an elastic body 13 that elastically connects the first mounting member 11 and the second mounting member 12 to each other. ) 14 and a partition member 16 for partitioning into a sub liquid chamber (second liquid chamber) 15. This is a liquid-filled type anti-vibration device.

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 from the axial direction, the direction that intersects the central axis O is referred to as the radial direction, and the direction that orbits around the central axis O is referred to as the 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 arranged coaxially with the central axis O.

When the vibration isolator 10 is mounted on an automobile, for example, the second mounting member 12 is connected to the engine as a vibration generating portion, and the first mounting member 11 is connected to the vehicle body as a vibration receiving portion. As a result, the vibration of the engine is suppressed from being transmitted to the vehicle body. The first mounting member 11 may be connected to the vibration generating portion, and the second mounting member 12 may be connected to the vibration receiving portion.

The second mounting member 12 is a columnar member extending in the axial direction, and is formed in a hemispherical shape in which the lower end portion bulges downward. In the second mounting member 12, a flange portion 12a protruding outward in the radial direction is formed in a portion located above the lower end portion of the hemispherical shape. A screw hole 12b extending downward from the upper end surface thereof is bored in the second mounting member 12, and a bolt (not shown) serving as a mounting tool on the engine side is screwed into the screw hole 12b. The second mounting member 12 is arranged at 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 adhered to the inner peripheral surface of the upper part of the first mounting member 11 and the outer peripheral surface of the lower part of the second mounting member 12, respectively, and is interposed between them. The upper end opening of the first mounting member 11 is closed from above. A first rubber film 13a covering the lower surface, the outer peripheral surface, and the upper surface of the flange portion 12a is integrally formed on the upper end portion of the elastic body 13. A second rubber film 13b that liquidally covers the inner peripheral surface of the first mounting member 11 is integrally formed at the lower end portion of the elastic body 13. As the elastic body 13, it is also possible to use an elastic body made of synthetic resin or the like in addition to rubber.

The first mounting 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 a soft resin, and is formed in 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 crimped and fixed in the lower end portion of the first mounting member 11. The upper end opening edges of the diaphragm 20 and the diaphragm ring 21 are in close contact with the lower surface of the partition member 16.

Since the diaphragm 20 is attached to the first attachment member 11 in this way, the inside of the first attachment member 11 is a liquid chamber 19 that is liquid-tightly sealed by the elastic body 13 and the diaphragm 20. .. The liquid L is sealed (filled) in the liquid chamber 19.
In the illustrated example, the bottom portion of the diaphragm 20 has a shape deep on the outer peripheral side and shallow in the central portion. However, as the shape of the diaphragm 20, various shapes known in the past 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 elastic body 13 and the second rubber film 13b that tightly covers the inner peripheral surface of the first mounting member 11 and the partition member 16. 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 used by attaching the main liquid chamber 14 so as to be located on the upper side in the vertical direction and the sub liquid chamber 15 to be located on the lower side in the vertical direction. ..

The partition member 16 is provided with a restriction passage 24 that communicates the main liquid chamber 14 and the sub liquid chamber 15. The limiting passage 24 is tuned so that resonance (liquid column resonance) occurs when, for example, a shake vibration having a frequency of about 10 Hz is input to the vibration isolator 10. As shown in FIG. 2, the restricted passage 24 has a first communication portion 26 that opens into the main liquid chamber 14, a second communication portion 27 that opens into the sub liquid chamber 15, and a first communication portion 26 and a second communication portion. A main body flow path 25 that communicates with 27 is provided.

The main body flow path 25 has a main flow path 31 extending from either one of the first communication section 26 and the second communication section 27 toward one side in the circumferential direction, and one end of the main flow path 31 in the circumferential direction. It includes an end chamber 34 that protrudes inward in the radial direction 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 arranged on the partition member 16 in an angle range of less than 360 ° about the central axis O. In the illustrated example, the main flow path 31 is arranged on the partition member 16 in an angle range exceeding 180 ° about the central axis O.

The main flow path 31 is arranged coaxially with the central axis O and is arranged coaxially with the central axis O and is located on the lower side with the lower surface of the annular upper barrier 35 which is located on the upper side and the front and back surfaces face in the axial direction. It is defined by the upper surface of the annular lower barrier 36 whose front and back surfaces face in the axial direction, and the groove bottom surface 37 which connects the inner peripheral edges of the upper barrier 35 and the lower barrier 36 and faces outward in the radial direction. There is.
The upper barrier 35 faces the main liquid chamber 14. The lower barrier 36 faces the auxiliary liquid chamber 15, and the second communication portion 27 is composed of one opening that penetrates the lower barrier 36 in the axial direction.

The end chamber 34 has a circular shape in a plan view seen from the axial direction, and the central axis of the end chamber 34 extends in the axial direction. The end chamber 34 is arranged at a position away from the central axis O. Hereinafter, in the plan view, the direction that intersects the central axis of the end chamber 34 is referred to as the end chamber radial direction, and the direction that orbits around the center axis of the end chamber 34 is referred to as the end chamber circumferential direction.
The external communication portion 46 connecting the end chamber 34 and the main flow path 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 external 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 of the main flow path 31 in the circumferential direction with respect to the external communication portion 46. The axial sizes of the outer communication portion 46 and the end chamber 34 are equal to each other.

Of the wall surfaces that define the end chamber 34, the upper wall surface that is located on the upper side and faces downward is the lower surface of the first barrier 38 whose upper surface faces the main liquid chamber 14, and is located on the lower side and faces 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 have a disk shape arranged coaxially with the central axis of the end chamber 34.

The first communication portion 26 includes a plurality of pores 26a and 26b penetrating the first barrier 38 facing the main liquid chamber 14. The pores 26a and 26b penetrate the first barrier 38 in the axial direction. That is, the opening directions of the pores 26a and 26b coincide with the axial direction, and are orthogonal to the extending direction R of the main body flow path 25 from the second communication portion 27 side to the first communication portion 26 side. ing. The pores 26a and 26b may be formed in the lower barrier 36 facing the auxiliary 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. The plurality of pores 26a and 26b are all smaller than the flow path cross-sectional area of the main flow path 31, and are arranged inside the end chamber 34 in a plan view seen from the axial direction.
The total of the flow path cross-sectional areas in each of the plurality of pores 26a and 26b may be, for example, 1.5 times or more and 4.0 times or less the minimum value of the flow path cross-sectional area of the main flow path 31. In the illustrated example, the flow path cross-sectional area of the main flow path 31 is the same over the entire length. The flow path 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.

The upper barrier 35 and the first barrier 38 that define the restricted passage 24 and face the main liquid chamber 14, and the lower barrier 36 that defines the restricted passage 24 and faces the auxiliary liquid chamber 15, and Of the second barrier 39, the thickness of the first barrier 38 in which the plurality of pores 26a and 26b are formed is thicker than the thickness of each 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 area. The upper surface and the lower surface 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 the other side of the first communication portion 26 and the second communication portion 27 to collide and branch. ..
In the illustrated example, the barrier rigid body 41 collides with the liquid L from the second communication portion 27 side to branch. The barrier rigid body 41 is arranged in the end chamber 34 of the main body flow path 25. The barrier rigid body 41 faces the first barrier 38 in the axial direction. As shown in FIG. 3, the barrier rigid body 41 is integrated with the bottom surfaces of two conical bodies whose diameters are gradually reduced from the inside to the outside in the axial direction, and is integrated in the end chamber radial direction. It has a diamond-shaped structure when viewed from the outside. The barrier rigid body 41 is arranged coaxially with the central axis of the end chamber 34. The surface of the barrier rigid body 41 is in non-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 in the restricted passage 24.
For example, the barrier rigid body 41 may have a structure, a columnar shape, a plate shape, or the like, in which the bottom surfaces of the two pyramidal bodies are butted against each other and integrated, and have a rhombic shape when viewed from the outside in the radial direction.

Of the surface of the barrier rigid body 41, the surface gradually extending downward from the central portion in the axial direction toward the inside in the radial direction of the end chamber causes the liquid L from the second communication portion 27 side to flow from below the barrier rigid body 41. It is a branch surface 41a that is made to collide and branch. Of the surface of the barrier rigid body 41, the surface gradually extending inward in the end chamber radial direction from the central portion in the axial direction gradually joins the liquid L branched by the branch surface 41a to form the barrier rigid body 41. It is a guide surface 41b that is passed upward and is guided to the first barrier 38. The magnitudes of 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 the same as each other.

On the surface of the barrier rigid body 41, a connecting piece 43 for fixing the barrier rigid body 41 to the wall surface of the end chamber 34 is arranged. A plurality of connecting pieces 43 are arranged on the surface of the barrier rigid body 41 at intervals in the circumferential direction of the end chamber. The connecting piece 43 fixes the barrier rigid body 41 to the inner peripheral surface of the wall surface defining the end chamber 34, which faces inward in the radial direction of the end chamber. The connecting piece 43 is arranged 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 arranged in the central portion in the axial direction of the barrier rigid body 41. .. The barrier rigid body 41 faces the external communication portion 46 without the connecting piece 43.

Of the plurality of pores 26a and 26b, the flow resistance of the pores 26a that are axially opposed to the barrier rigid body 41 (hereinafter referred to as facing pores) is the remaining fine pores that are not axially opposed to the barrier rigid body 41. It is larger than the flow resistance of the pores (hereinafter referred to as non-opposed pores) 26b.

In the illustrated example, the non-opposed pores 26b are axially opposed to the lower wall surface (inner surface of the main body flow path 25) of the end chamber 34 without passing through the barrier rigid body 41. The non-opposed pores 26b are arranged on the outer peripheral portion of the first barrier 38, and the opposed pores 26a are arranged on the central portion of the first barrier 38 located radially inside from the outer peripheral portion. The inner diameter of the opposed pores 26a is smaller than the inner diameter of the non-opposed pores 26b. The flow path lengths of the opposed pores 26a and the non-opposed pores 26b are equal to each other. The plurality of facing pores 26a have the same shape and the same size. The plurality of non-opposed pores 26b also have the same shape and the same size.

The flow path length of the opposed pores 26a may be longer than the flow path length of the non-opposed pores 26b, and the inner peripheral surface of the non-opposed pores 26b may be made a smooth surface while the opposed pores. Concavo-convex portions may be formed on the inner peripheral surface of 26a, and the flow resistance of the facing pores 26a can be reduced by appropriately adjusting at least one such as the inner diameter and the flow path length. It may be larger than the distribution resistance.

Here, the partition member 16 is configured such that the upper member 47, the intermediate member 42, and the lower member 48 are overlapped in the axial direction. The upper member 47, the intermediate member 42, and the lower member 48 are each formed in a plate shape with the front and back surfaces facing in the axial direction. The upper member 47 and the lower member 48 are each formed in a disk shape coaxially arranged with the central axis O. 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 of the intermediate member 42, which will be described later, form 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. The end chamber 34 is defined by the inner surfaces of the first recess and the second recess. A 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 a first barrier 38. The portion of the lower member 48 where the second recess is located is the second barrier 39.
An annular lower barrier 36 is formed on the outer peripheral surface of the upper end portion of the lower member 48 so as to project outward in the radial direction and to form the second communication portion 27. On the outer peripheral surface of the upper end portion of the upper member 47, an upper barrier 35 that projects 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 arranged so as to be sandwiched between the lower surface of the upper member 47 and the upper surface of the lower member 48. In the plan view, the outer peripheral surface of the intermediate member 42 is a second chord portion that connects both ends of the second arc portion 42a forming a part of the groove bottom surface 37 and both ends of the second arc portion 42a and extends linearly. It is composed of 42b and. In the plan view, the intermediate member 42 is formed with a semicircular opening 42c that opens into the second chord portion 42b, and the inner peripheral surface of the opening 42c forms a part of the inner peripheral surface of the end chamber 34. Nothing. A barrier rigid body 41 is connected to the inner peripheral surface of the opening 42c via 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 integrally formed with the intermediate member 42.

In the vibration isolator 10 having such a configuration, both mounting 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 restricted passage 24, and the liquid L in the sub liquid chamber 15 flows into the restricted passage 24. It flows into the main liquid chamber 14 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 restricted passage 24 through the plurality of pores 26a and 26b, these pores 26a , 26b flows through the pores 26a and 26b while being pressure-lossed by the first barrier 38 formed therein, so that the flow velocity of the liquid L flowing into the main liquid chamber 14 can be suppressed. Moreover, since the liquid L circulates through a plurality of pores 26a and 26b instead of the single pores 26a and 26b, the liquid L can be branched and circulated into a plurality of pores 26a and 26b. The flow velocity of the liquid L that has passed through 26b can be reduced. As a result, even if a large load (vibration) is input to the vibration isolator 10, the liquid L that has passed through the pores 26a and 26b and has flowed into the main liquid chamber 14 and the liquid L in the main liquid chamber 14 It is possible to suppress the difference in flow velocity generated between the two, and the generation of vortices due to the difference in flow velocity and the generation of bubbles due to this vortex can be suppressed.

Further, even if bubbles are generated in the restricted passage 24 instead of the main liquid chamber 14, the generated bubbles are separated from each other in the main liquid chamber 14 by allowing the liquid L to pass through the plurality of pores 26a and 26b. It is possible to prevent the bubbles from merging and growing, and it is possible to easily maintain the state in which the bubbles are finely dispersed.
As described above, it is possible to suppress the generation of bubbles themselves, and even if bubbles are generated, it is possible to easily maintain the state in which the bubbles are finely dispersed, so that cavitation collapse occurs in which the bubbles collapse. However, the generated abnormal noise can be suppressed to a small level.

In particular, since the barrier rigid body 41 that collides and branches the liquid L from the second communication portion 27 side is disposed in the main body flow path 25, the liquid L from the second communication portion 27 side is used as the first barrier. By colliding with the barrier rigid body 41 and branching it before reaching 38, a pressure loss can be caused in the liquid L. This makes it possible to reliably reduce the flow velocity of the liquid L from the second communication portion 27 side before reaching the first barrier 38, and the inner diameters of the pores 26a and 26b do not become excessively small. However, the abnormal noise caused by the collapse of cavitation can be surely suppressed to a small level.

Further, 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 to branch. The liquids L collide with each other, causing a pressure loss. Therefore, by passing the liquid L from the second communication portion 27 side through the barrier rigid body 41, the flow velocity of the liquid L can be reduced more reliably before reaching the first barrier 38.

Further, the flow resistance of the opposed pores 26a, which is axially opposed to the barrier rigid body 41, passes through the barrier rigid body 41 and joins, and the liquid L having a relatively large flow rate flows into the barrier rigid body 41, is axially opposed to the barrier rigid body 41. Since it is larger than the flow resistance of the non-opposed pores 26b into which the liquid L which is not opposed and has a relatively small flow rate flows in, the liquid L from the second communication portion 27 side is barriered to the plurality of pores 26a and 26b. Regardless of whether or not it faces the rigid body 41 in the axial direction, it can flow evenly with little bias.

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

For example, in the above embodiment, the barrier rigid body 41 is arranged in the end chamber 34 of the main body flow path 25, but it may be arranged in the main flow path 31 or the outer communication portion 46, and the barrier rigid body 41 is the first communication portion. The liquid L from the 26 side may be collided and branched.
Further, both the first communication portion 26 and the second communication portion 27 may adopt a configuration having pores 26a and 26b.
Further, although the configuration in which the partition member 16 orbits the partition member 16 about once is shown as the main flow path 31, a configuration in which the partition member 16 orbits the partition member 16 longer than one circumference may be adopted.
Further, as the main body flow path 25, for example, a configuration extending in the axial direction, a configuration having no end chamber 34, or the like may be adopted.

Further, 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, but the flow resistance is not limited to this, and for example, as shown in FIG. 4, the lower surface of the first barrier 38 ( On the inner surface facing the main body flow path 25 side), the ratio of the opening area of the facing pores 26a to the flat area of the portion facing the barrier rigid body 41 in the axial direction is axially opposed to the remaining barrier rigid body 41. It may be smaller than the ratio of the opening area of the non-opposed pores 26b to the flat area of the non-opposed portion.
In the illustrated example, the non-opposed pores 26b are axially opposed to the lower wall surface of the end chamber 34 without the barrier rigid body 41. The inner diameters of the opposed pores 26a and the non-opposed pores 26b are equal to each other.

In this case, on the lower surface of the first barrier 38, it faces the barrier rigid body 41 in the axial direction, passes through the barrier rigid body 41, merges, and occupies the flat 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 higher than the ratio of the opening area of the non-opposing pores 26b to the flat area of the portion where the liquid L having a relatively small flow rate is guided, which does not face the barrier rigid body 41 in the axial direction. Since it is small, the liquid L from the second communication portion 27 side can flow into the plurality of pores 26a and 26b evenly with little bias regardless of whether or not it faces the barrier rigid body 41 in the axial direction. ..

Further, after making the flow resistance of the opposed pores 26a larger than the flow resistance of the non-opposed pores 26b, as shown in FIG. 4, the lower surface of the first barrier 38 faces the barrier rigid body 41 in the axial direction. The ratio of the opening area of the opposed pores 26a to the flat area of the portion is made smaller than the ratio of the opening area of the non-opposed pores 26b to the flat area of the remaining portion not axially opposed to the barrier rigid body 41. You may.

Further, in the above-described embodiment, the guide surface 41b is formed on the barrier rigid body 41, but the barrier rigid body 41 having no 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 facing pore 26a than the non-opposing pore 26b, so that the flow resistance of the facing pore 26a is changed to the flow resistance of the non-opposing pore 26b. It may be smaller, and the ratio of the opening area of the facing pores 26a to the flat area of the portion axially facing the barrier rigid body 41 on the lower surface of the first barrier 38 is set to the remaining barrier rigid body 41. It may be larger than the ratio of the opening area of the non-opposed pores 26b to the flat area of the non-opposed portions in the axial direction.
Further, the barrier rigid body 41 may be brought close to the lower surface of the first barrier 38 and separated 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 can be further increased more reliably. Can be done.

Further, in the above embodiment, the compression type anti-vibration device 10 in which a positive pressure acts on the main liquid chamber 14 by the action of a supporting load has been described, but the main liquid chamber 14 is located on the lower side in the vertical direction and The auxiliary liquid chamber 15 is attached so as to be located on the upper side in the vertical direction, and can be applied to a suspension type vibration isolator in which a negative pressure acts on the main liquid chamber 14 by the action of a supporting load.

Further, in the above embodiment, the partition member 16 partitions the liquid chamber 19 in the first mounting member 11 into a main liquid chamber 14 having an elastic body 13 as a part of a wall surface and a 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 as 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 are used. It is possible to appropriately change to another configuration in which at least one of both liquid chambers has the elastic body 13 as a part of the wall surface.

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

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

10 Anti-vibration device 11 1st mounting member 12 2nd mounting 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 Restricted passage 25 Main body flow path 26 First communication part 26a, 26b Pore 27 Second communication part 38 First barrier 41 Barrier rigid body 41b Guide surface L Liquid O Center axis

Claims (4)

A cylindrical first mounting member connected to either one of the vibration generating portion and the vibration receiving portion, and a second mounting member connected to the other.
An elastic body that elastically connects these two mounting members,
A partition member for partitioning the liquid chamber in the first mounting member in which the liquid is sealed into the first liquid chamber and the second liquid chamber is provided, and the liquid chamber is provided.
A liquid-filled type anti-vibration device in which a limiting passage connecting the first liquid chamber and the second liquid chamber is formed in the partition member.
The restricted passage includes a first communication portion that opens into the first liquid chamber, a second communication portion that opens into the second liquid chamber, and a main body flow path that communicates the first communication portion with the second communication portion. Equipped with
At least one of the first communication section and the second communication section includes a plurality of pores penetrating the first barrier facing the first liquid chamber or the second liquid chamber.
A vibration isolator characterized in that a barrier rigid body is provided in the main body flow path so that a liquid from any one of the first communication portion and the second communication portion collides with and branches. The vibration isolator according to claim 1, wherein the barrier rigid body is formed with a guide surface that guides the liquid from the other side that has collided and branched to the first barrier. The barrier rigid body faces the first barrier in the opening direction of the pores.
The protection according to claim 2, wherein 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 among the plurality of pores. Shaking device. The barrier rigid body faces the first barrier in the opening direction of the pores.
On the inner surface of the first barrier facing the main body flow path 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 anti-vibration device according to claim 2 or 3, wherein the vibration isolator is smaller than the ratio of the opening area of the pores to the pores.

Images