JP2021076164A - Antivibration device - Google Patents

Abstract

To attenuate and absorb midfrequency vibration.SOLUTION: In a partition member 16, there are formed an orifice channel 24 communicating a main liquid chamber 14 with a sub liquid chamber 15, a plurality of first communication holes 42a communicating the main liquid chamber with a storage chamber 42, and a second communication hole 42b communicating the sub liquid chamber with the storage chamber. In the partition member, a first wall surface 16b in which the first communication hole is opened and which constitutes a part of an inner surface of the main liquid chamber, is provided with a cylindrical member 21 protruding toward an elastic body 13 in an axial direction. The plurality of first communication holes are opened on the first wall surface both in an inner part 16f located inside the cylindrical member and in an outer part 16g located outside the cylindrical member. A passage resistance of fluid passing through the first communication hole opened in the outer part and a passage resistance of fluid passing through the first communication hole opened in the inner part are different from each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vibration isolator that is applied to, for example, automobiles, industrial machines, etc., and absorbs and attenuates vibrations of vibration generating parts such as engines.

Conventionally, as this type of vibration isolator, 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 of them. A partition member that partitions the elastic body that elastically connects the mounting members and the liquid chamber in the first mounting member in which the liquid is sealed into a main liquid chamber and a sub liquid chamber that have the elastic body as a part of the partition wall. A movable member that is deformably or displaceably housed in a storage chamber provided in the member is provided, and the partition member includes an orifice passage that communicates the main liquid chamber and the sub liquid chamber, and a main liquid chamber and the storage chamber. It is known that a plurality of first communication holes for communicating with each other and a second communication hole for communicating with the auxiliary liquid chamber and the storage chamber are formed.
In this vibration isolator, when idle vibration with a relatively high frequency is input in the axial direction among low-frequency vibrations with a frequency of less than 200 Hz, the movable member is deformed or displaced in the accommodation chamber, and the liquid in the liquid chamber is liquid. By circulating the first communication hole and the second communication hole, idle vibration is attenuated and absorbed, and when shake vibration with a relatively low frequency is input in the axial direction, the liquid in the liquid chamber is removed. , Shake vibration is dampened and absorbed by circulating through the orifice passage.

JP-A-2002-327789

However, the conventional anti-vibration device cannot attenuate and absorb medium-frequency vibration having a frequency of 200 Hz to 1000 Hz.

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 attenuating and absorbing medium frequency vibration.

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 first mounting member is provided with an elastic body that elastically connects the two, and a liquid chamber in the first mounting member in which a liquid is sealed, in a main liquid chamber and a sub liquid chamber having the elastic body as a part of a partition wall. A partition member that partitions in the axial direction along the central axis of the above, and a movable member that is deformably or displaceably housed in a storage chamber provided in the partition member, and the partition member includes the main liquid chamber and the main liquid chamber. An orifice passage communicating with the auxiliary liquid chamber, a plurality of first communication holes communicating with the main liquid chamber and the accommodation chamber, and a second communication hole communicating with the auxiliary liquid chamber and the accommodation chamber are provided. A tubular member formed in the partition member, the first communication hole is opened, and the first wall surface forming a part of the inner surface of the main liquid chamber is projected in the axial direction toward the elastic body. Is arranged, and the plurality of first communication holes are opened in both the inner portion located inside the tubular member and the outer portion located outside the tubular member on the first wall surface. A vibration isolator in which the flow resistance of the liquid flowing through the first communication hole opened in the outer portion and the flow resistance of the liquid flowing through the first communication hole opened in the inner portion are different from each other.

According to the present invention, since a tubular member projecting toward the elastic body is arranged on the first wall surface of the partition member, a vertical cross-sectional view along the axial direction is performed with the input of medium-frequency vibration in the axial direction. In the above, when the elastic body is deformed in the secondary vibration mode, the node portion conventionally generated in the central portion of the elastic body is, for example, between the inner peripheral surface of the main liquid chamber and the outer peripheral surface of the tubular member. Due to the difficulty of flowing the liquid, the elastic body shifts to the second mounting member side, and the elastic body is first mounted from the knot portion as compared with the portion located on the second mounting member side from the knot portion. The portion located on the member side is easily deformed. As a result, when the medium frequency vibration in the axial direction is input, the portion of the elastic body located closer to the first mounting member than the node portion is positively deformed, and the rigidity of the elastic body can be apparently reduced. This vibration can be damped and absorbed.
Further, since a plurality of first communication holes are opened in both the inner portion located inside the tubular member and the outer portion located outside the tubular member on the first wall surface, the first wall surface has a plurality of first communication holes. Many first communication holes can be arranged, and for example, idle vibration having a relatively high frequency among low frequency vibrations can be reliably attenuated and absorbed.
Further, since the flow resistance of the liquid flowing through the first communication hole opened in the outer portion and the flow resistance of the liquid flowing through the first communication hole opened in the inner portion are different from each other, the inside of the main liquid chamber. The flow state of the liquid between the peripheral surface and the outer peripheral surface of the tubular member, such as the flow velocity, can be adjusted, and the position of the node portion can be easily adjusted.
Further, by designing the first communication hole formed in the first wall surface instead of the tubular member protruding from the first wall surface, the liquid between the inner peripheral surface of the main liquid chamber and the outer peripheral surface of the tubular member Since it becomes possible to adjust the flow state of the above, it is possible to make it less likely to cause design restrictions as compared with the case where the tubular member is designed and the flow state is adjusted.

The flow path cross-sectional area of the first communication hole that opens in the outer portion and the flow path cross-sectional area of the first communication hole that opens in the inner portion may be different from each other.

In this case, since the flow path cross-sectional area of the first communication hole that opens in the outer portion and the flow path cross-sectional area of the first communication hole that opens in the inner portion are different from each other, the former first communication hole is circulated. The flow resistance of the liquid flowing through the first communication hole and the flow resistance of the liquid flowing through the first communication hole of the latter can be surely made different from each other.

The flow path length of the first communication hole that opens in the outer portion and the flow path length of the first communication hole that opens in the inner portion may be different from each other.

In this case, since the flow path length of the first communication hole opened in the outer portion and the flow path length of the first communication hole opened in the inner portion are different from each other, the liquid flowing through the former first communication hole The flow resistance of the latter and the flow resistance of the liquid flowing through the first communication hole of the latter can be surely made different from each other.

The number of the first communication holes opened in the outer portion and the number of the first communication holes opened in the inner portion may be different from each other.

In this case, since the number of first communication holes opened in the outer portion and the number of first communication holes opened in the inner portion are different from each other, the inner peripheral surface of the main liquid chamber and the outer peripheral surface of the tubular member are different from each other. It becomes easy to adjust the flow state of the liquid between and, for example, the flow velocity, and the position of the node portion can be easily adjusted.

The flow resistance of the liquid flowing through the first communication hole opened in the outer portion may be higher than the flow resistance of the liquid flowing through the first communication hole opened in the inner portion.

In this case, the flow resistance of the liquid flowing through the first communication hole opened in the outer portion is higher than the flow resistance of the liquid flowing through the first communication hole opened in the inner portion, so that the inner peripheral surface of the main liquid chamber and the cylinder The liquid between the shape member and the outer peripheral surface becomes less likely to flow, and when the medium frequency vibration in the axial direction is input, the node portion can be reliably shifted to the second mounting member side, and the medium frequency vibration. Can be reliably attenuated and absorbed.

According to the present invention, medium frequency vibration can be attenuated and absorbed.

It is a vertical sectional view of the vibration isolation device which concerns on 1st Embodiment of this invention. FIG. 5 is a cross-sectional view taken along the line AA of the vibration isolator shown in FIG. It is a vertical sectional view of the vibration isolation device which concerns on 2nd Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line BB of the vibration isolator shown in FIG.

Hereinafter, embodiments of the vibration isolator according to the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the vibration isolator 1 is attached to a tubular first mounting member 11 connected to either one of the vibration generating portion and the vibration receiving portion and to either one of the vibration generating portion and the vibration receiving portion. The second mounting member 12 to be connected, the elastic body 13 elastically connecting the first mounting member 11 and the second mounting member 12 to each other, and the liquid chamber 19 in the first mounting member 11 in which the liquid is sealed are separated from each other. A partition member 16 that divides the main liquid chamber 14 and the sub liquid chamber 15 having an elastic body 13 as a part of a partition wall, and a movable member 41 that is deformably or displaceably housed in a storage chamber 42 provided in the partition member 16. It is a liquid-filled type anti-vibration device equipped with.

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 1 viewed from the axial direction, the direction intersecting the central axis O is referred to as the radial direction, and the direction rotating 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 each have a circular shape or an annular shape in a plan view, and are arranged coaxially with the central axis O.

When the vibration isolator 1 is mounted on an automobile, for example, the second mounting member 12 is connected to an engine or the like as a vibration generating portion, and the first mounting member 11 is connected to a vehicle body as a vibration receiving portion. As a result, the vibration of the engine or the like 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 first mounting member 11 includes an inner cylinder portion 11a, an outer cylinder portion 11b, and a lower support portion 11c.
The inner cylinder portion 11a is fitted in the outer cylinder portion 11b. The lower support portion 11c is formed in an annular shape. The lower end opening edge of the outer cylinder portion 11b is placed on the upper surface of the outer peripheral portion of the lower support portion 11c. The first mounting member 11 is formed in a cylindrical shape as a whole. The first mounting member 11 is connected to a vehicle body or the like as a vibration receiving portion via a bracket (not shown).

The second mounting member 12 is located inside and above the first mounting member 11 in the radial direction. The outer diameter of the second mounting member 12 is smaller than the inner diameter of the first mounting member 11. The second mounting member 12 is connected to an engine or the like as a vibration generating portion via the mounting bracket by fitting a mounting bracket (not shown) inside.
The relative positions of the first mounting member 11 and the second mounting member 12 are not limited to the illustrated example and may be changed as appropriate. Further, the outer diameter of the second mounting member 12 may be equal to or larger than the inner diameter of the first mounting member 11.

The elastic body 13 is formed in a tubular shape extending in the axial direction. The diameter of the elastic body 13 increases from the upper side to the lower side.
A first mounting member 11 and a second mounting member 12 are separately connected to both ends of the elastic body 13 in the axial direction. The second mounting member 12 is connected to the upper end of the elastic body 13, and the first mounting member 11 is connected to the lower end of the elastic body 13. The elastic body 13 closes the upper end opening of the first mounting member 11. The lower end of the elastic body 13 is connected to the inner peripheral surface of the inner cylinder portion 11a of the first mounting member 11. The upper end of the elastic body 13 is connected to the lower surface of the second mounting member 12. The elastic body 13 is formed of a rubber material or the like, and is vulcanized and adhered to the first mounting member 11 and the second mounting member 12. The thickness of the elastic body 13 becomes thinner from the upper side to the lower side. The elastic body 13 may be formed of, for example, a synthetic resin material.
A stopper rubber 13a that covers the outer peripheral surface and the upper surface of the second mounting member 12 is integrally formed at the upper end portion of the elastic body 13. An outer shell body 12a surrounding the second mounting member 12 is embedded in the elastic body 13 and the stopper rubber 13a.

The diaphragm 20 is made of an elastic material such as rubber or a soft resin, and is formed in a bottomed cylindrical shape. By sandwiching the upper end portion of the diaphragm 20 between the inner peripheral portion of the lower support portion 11c of the first mounting member 11 and the outer peripheral portion of the partition member 16, the liquidtightness inside the diaphragm 20 is ensured, and The lower end opening of the first mounting member 11 is closed.
In the illustrated example, the bottom portion of the diaphragm 20 has a shape deep on the outer peripheral side and shallow on the central portion. However, as the shape of the diaphragm 20, in addition to such a shape, various conventionally known shapes can be adopted.

The diaphragm 20 closes the lower end opening of the first mounting member 11, and as described above, the elastic body 13 closes the upper end opening of the first mounting member 11, so that the inside of the first mounting member 11 is liquid-tight. It is a liquid chamber 19 sealed in. A liquid is sealed (filled) in the liquid chamber 19. Examples of the liquid include ethylene glycol, water, silicone oil and the like.

The liquid chamber 19 is axially divided into a main liquid chamber 14 and a sub liquid chamber 15 by a partition member 16. The main liquid chamber 14 has an inner peripheral surface 13c of the elastic body 13 as a part of the wall surface, and is a space surrounded by the elastic body 13 and the partition member 16, 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 1 having such a configuration is a compression type device in which the main liquid chamber 14 is located on the upper side in the vertical direction and the sub liquid chamber 15 is located on the lower side in the vertical direction. ..

The partition member 16 is formed with a plurality of first communication holes 42a communicating the main liquid chamber 14 and the storage chamber 42, and a second communication hole 42b communicating the sub liquid chamber 15 and the storage chamber 42. .. A plurality of the second communication holes 42b are formed in the partition member 16, and the numbers of the first communication holes 42a and the second communication holes 42b are the same. The first communication hole 42a and the second communication hole 42b face each other in the axial direction. The inner diameters (flow path cross-sectional areas) of the first communication hole 42a and the second communication hole 42b facing each other in the axial direction are the same. The flow path lengths of the first communication hole 42a and the second communication hole 42b facing each other in the axial direction are the same. One second communication hole 42b may be formed in the partition member 16.

Here, in the partition member 16, the upper wall surface forming a part of the inner surface of the main liquid chamber 14 and the lower wall surface forming a part of the inner surface of the sub liquid chamber 15 are respectively the central axis O when viewed from the axial direction. It has a circular shape arranged coaxially with. The diameters of the upper wall surface and the lower wall surface of the partition member 16 are equal to each other. The upper wall surface of the partition member 16 is axially opposed to the inner peripheral surface 13c of the elastic body 13, and the lower wall surface of the partition member 16 is axially opposed to the inner surface of the diaphragm 20.

In the illustrated example, a recess is formed on the upper wall surface of the partition member 16 over the entire area except the outer peripheral edge portion 16a. A plurality of first communication holes 42a are opened over the entire area of the bottom surface (hereinafter, referred to as the first wall surface) 16b of the recessed portion. A recess is formed on the lower wall surface of the partition member 16 over the entire area except the outer peripheral edge portion 16c. A plurality of second communication holes 42b are opened over the entire area of the bottom surface (hereinafter referred to as the second wall surface) 16d of the recessed portion. Each recessed portion of the upper wall surface and the lower wall surface has a circular shape arranged coaxially with the central axis O when viewed from the axial direction, and the sizes such as the inner diameter and the depth of each recessed portion are the same as each other. ..

The storage chamber 42 is formed in a portion of the partition member 16 located between the first wall surface 16b and the second wall surface 16d in the axial direction. The accommodation chamber 42 has a circular shape arranged coaxially with the central axis O when viewed from the axial direction. The diameter of the containment chamber 42 is larger than the diameters of the first wall surface 16b and the second wall surface 16d.
The movable member 41 is formed in a plate shape with the front and back surfaces facing in the axial direction. The movable member 41 has a circular shape arranged coaxially with the central axis O when viewed from the axial direction. The movable member 41 is made of an elastic material such as rubber or a soft resin.

The partition member 16 is formed with an orifice passage 24 that communicates the main liquid chamber 14 and the sub liquid chamber 15. The orifice passage 24 is formed in the partition member 16 at a portion located between the outer peripheral edge portion 16a of the upper wall surface and the outer peripheral edge portion 16c of the lower wall surface in the axial direction. The upper end of the orifice passage 24 is located above the first wall surface 16b, and the lower end of the orifice passage 24 is located below the second wall surface 16d. The cross-sectional shape of the orifice passage 24 is rectangular, which is long in the axial direction. The resonance frequency of the orifice passage 24 is lower than the resonance frequencies of the first communication hole 42a and the second communication hole 42b.

As shown in FIG. 2, the opening 25 on the main liquid chamber 14 side in the orifice passage 24 is formed in the outer peripheral edge portion 16a of the upper wall surface of the partition member 16. The opening 25 is configured such that a plurality of hole rows 25b in which a plurality of through holes 25a are arranged at intervals in the circumferential direction are arranged at different positions in the radial direction and the circumferential direction. The inner diameter of the through hole 25a is smaller than the inner diameter of the first communication hole 42a. Two hole rows 25b are arranged on the outer peripheral edge portion 16a of the upper wall surface of the partition member 16. The amount of deviation in the circumferential direction of each hole row 25b and the amount of deviation in the radial direction of each hole row 25b are equal to the inner diameter of the through hole 25a, respectively.

The opening on the auxiliary liquid chamber 15 side of the orifice passage 24 is formed in the outer peripheral edge portion 16c of the lower wall surface of the partition member 16, and the opening area of the opening 25 on the main liquid chamber 14 side, that is, the openings of the plurality of through holes 25a. It is one opening whose opening area is larger than the total area. The opening 25 on the main liquid chamber 14 side and the opening on the sub-liquid chamber 15 side in the orifice passage 24 are located radially outside the first communication hole 42a and the second communication hole 42b.

A flange portion 16e is formed at the upper end portion of the partition member 16 so as to project outward in the radial direction and extend continuously over the entire circumference. The upper surface of the flange portion 16e is in contact with the lower end opening edges of the inner cylinder portion 11a and the outer cylinder portion 11b of the first mounting member 11 via the annular upper sealing material 27. The lower surface of the flange portion 16e is on the upper surface of the inner peripheral portion of the lower support portion 11c of the first mounting member 11, the upper end opening edge of the diaphragm 20, and the lower end of the ring that surrounds the upper end opening edge of the diaphragm 20 from the outside in the radial direction. They are in contact with each other via the sealing material 28.

The partition members 16 include an upper cylinder 31 and a lower cylinder 32 arranged so as to be abutted against each other in the axial direction, an upper wall 33 that closes the lower end opening of the upper cylinder 31, and an upper end opening of the lower cylinder 32. It is provided with a lower wall 34 for closing the space. The partition member 16 may be integrally formed.

The upper end opening edge of the upper cylinder 31 is the outer peripheral edge portion 16a of the upper wall surface of the partition member 16 described above. A flange portion 16e is formed at the upper end portion of the upper cylinder 31. At the lower end opening edge of the upper cylinder 31, a peripheral groove that is recessed upward and opens outward in the radial direction is formed in a portion located on the outer side in the radial direction from the inner peripheral portion.
The upper wall 33 is fixed to the inner peripheral portion of the lower end opening edge of the upper cylinder 31. A first communication hole 42a is formed in the upper wall 33.

At the upper end opening edge of the lower cylinder 32, a peripheral groove that is recessed downward is formed in a radial intermediate portion that faces the peripheral groove of the upper cylinder 31 in the axial direction. The orifice passage 24 is defined by the peripheral groove and the peripheral groove of the upper cylinder 31. At the upper end opening edge of the lower cylinder 32, the outer peripheral edge portion located on the outer side in the radial direction from the peripheral groove is in contact with the lower surface of the flange portion 16e of the upper cylinder 31. The lower cylinder 32 is fitted in the upper end portion of the diaphragm 20, and the upper end portion of the diaphragm 20 is fitted in the lower support portion 11c of the first mounting member 11. As a result, the upper end portion of the diaphragm 20 is sandwiched in the radial direction by the outer peripheral surface of the lower cylinder 32 and the inner peripheral surface of the lower support portion 11c.
The lower wall 34 is fixed to the inner peripheral portion of the upper end opening edge of the lower cylinder 32. A second communication hole 42b is formed in the lower wall 34.

Abutment protrusions 34a and 34b are formed on at least one of the inner peripheral portion at the lower end opening edge of the upper cylinder 31 and the inner peripheral portion at the upper end opening edge of the lower cylinder 32 so as to project and abut against the other. ing. In the illustrated example, the abutting protrusions 34a and 34b are formed on both the inner peripheral portion at the lower end opening edge of the upper cylinder 31 and the inner peripheral portion at the upper end opening edge of the lower cylinder 32. The abutting protrusions 34a and 34b are formed in an annular shape coaxially with the central axis O, and the upper wall 33 and the lower wall 34 are arranged inside the abutting protrusions 34a and 34b in the radial direction with a gap in the axial direction. Has been done. The accommodation chamber 42 is defined by the lower surface of the upper wall 33, the upper surface of the lower wall 34, and the inner peripheral surfaces of the abutting protrusions 34a and 34b.

Then, in the present embodiment, in the partition member 16, the first communication hole 42a opens, and the first wall surface 16b forming a part of the inner surface of the main liquid chamber 14 projects axially toward the elastic body 13. A tubular member 21 is arranged.

The tubular member 21 is formed in a cylindrical shape and is arranged coaxially with the central axis O. The tubular member 21 extends straight in the axial direction. The axial length of the tubular member 21 is 20% or more of the maximum axial height T of the main liquid chamber 14. In the illustrated example, the maximum axial height T of the main liquid chamber 14 extends inward in the radial direction from the bottom to the top, and the upper end portion of the inner peripheral surface 13c of the elastic body 13 and the first It is the axial distance from the wall surface 16b. The axial length of the tubular member 21 is such that the upper end of the tubular member 21 is an elastic body when an axial static load is applied to the vibration isolator 1 and when axial vibration is input. It is set so as not to come into contact with the inner peripheral surface 13c of 13.
As described above, the inner peripheral surface 13c of the elastic body 13 is a portion extending inward in the radial direction from the lower side to the upper side, and is the upper end portion of the inner peripheral surface 13c of the elastic body 13. , As shown in the illustrated example, when the upper end portion of the inner surface of the elastic body 13 that defines the main liquid chamber 14 is provided with a recess portion that is recessed upward, the recess on the inner surface of the elastic body 13 is provided. It is the opening peripheral edge of the portion.

The upper portion of the tubular member 21 projects upward from the upper end opening of the recessed portion formed on the upper wall surface of the partition member 16. The outer peripheral surface of the upper portion of the tubular member 21 is radially opposed to the lower end portion of the inner peripheral surface of the inner tubular portion 11a of the first mounting member 11 and the lower end portion of the inner peripheral surface 13c of the elastic body 13. The protruding length of the upper part of the tubular member 21 from the upper end opening of the recessed portion is shorter than the depth of the recessed portion. Further, the protruding length is the axial distance between the portion of the inner peripheral surface 13c of the elastic body 13 where the upper end opening edge of the tubular member 21 faces in the axial direction and the upper end opening edge of the tubular member 21. Shorter. Of the inner peripheral surface 13c of the elastic body 13 extending inward in the radial direction from the lower side to the upper side, in a vertical cross-sectional view along the axial direction, the inner peripheral surface 13c is below the central portion in the extending direction. The upper end opening edge of the tubular member 21 faces the portion displaced in the axial direction.

The radius of the inner peripheral surface of the tubular member 21 is larger than the radial distance between the outer peripheral surface of the tubular member 21 and the inner peripheral surface of the recessed portion formed on the upper wall surface of the partition member 16. The inner diameter of the tubular member 21 is more than half of the maximum inner diameter R of the main liquid chamber 14. In the illustrated example, the maximum inner diameter R of the main liquid chamber 14 is the inner diameter of the lower end of the inner cylinder portion 11a of the first mounting member 11. In the first wall surface 16b, the flat area of the portion 16f located inside the tubular member 21 (hereinafter referred to as the inner portion) is the flat area of 16 g of the portion located outside the tubular member 21 (hereinafter referred to as the outer portion). Greater.

The plurality of first communication holes 42a are open to both the inner portion 16f and the outer portion 16g of the first wall surface 16b. The plurality of first communication holes 42a all face the upper surface of the movable member 41.
The tubular member 21 is connected to a portion of the first wall surface 16b located between adjacent first communication holes 42a, and is arranged so as not to overlap the first communication holes 42a. The tubular member 21 is arranged so that the inner peripheral surface and the outer peripheral surface are in contact with the first communication hole 42a when viewed from the axial direction.

The quantity of the first communication hole 42a that opens in the outer portion 16g and the quantity of the first communication hole 42a that opens in the inner portion 16f are different from each other. In the illustrated example, the number of first communication holes 42a opening in the outer portion 16g is smaller than the number of first communication holes 42a opening in the inner portion 16f.
The ratio of the opening area of the first communication hole 42a to the flat area of the outer portion 16g and the ratio of the opening area of the first communication hole 42a to the flat area of the inner portion 16f are different from each other. In the illustrated example, the ratio of the opening area of the first communication hole 42a to the flat area of the outer portion 16g is smaller than the ratio of the opening area of the first communication hole 42a to the flat area of the inner portion 16f.
The total opening area of the first communication hole 42a that opens in the inner portion 16f is larger than the total opening area of the first communication hole 42a that opens in the outer portion 16g.

A plurality of first communication holes 42a that open in the outer portion 16g are arranged at equal intervals D in the circumferential direction over the entire length of the outer portion 16g in the circumferential direction.
A plurality of first communication holes 42a that open in the inner portion 16f are arranged at equal intervals over the entire area of the inner portion 16f. In the inner portion 16f, a plurality of first communication holes 42a are arranged at equal intervals B in the circumferential direction, and rows of the first communication holes 42a arranged in the circumferential direction are equal in the radial direction. A plurality of them are arranged concentrically around the central axis O with an interval C.

In the inner portion 16f, the distances B and C between the first communication holes 42a adjacent to each other are smaller than the inner diameter of the first communication holes 42a. In the outer portion 16g, the distance D between the first communication holes 42a adjacent to each other is larger than the inner diameter of the first communication holes 42a. In the inner portion 16f, the distances B and C between the first communication holes 42a adjacent to each other are different from each other, and in the outer portion 16g, the distance D between the first communication holes 42a adjacent to each other is different from each other.
In the illustrated example, the distances B and C between the first communication holes 42a adjacent to each other in the inner portion 16f are narrower than the distance D between the first communication holes 42a adjacent to each other in the outer portion 16g. In the inner portion 16f, the circumferential distance B and the radial distance C between the first communication holes 42a adjacent to each other are larger than the circumferential distance D between the first communication holes 42a adjacent to each other in the outer portion 16g. It's getting narrower. In the inner portion 16f, the circumferential distance B and the radial distance C between the first communication holes 42a adjacent to each other are equal to each other.

In the inner portion 16f, the distances B and C between the first communication holes 42a adjacent to each other may be set to be equal to or larger than the distance D between the first communication holes 42a adjacent to each other in the outer portion 16g, and the inner portion 16f. The circumferential distance B and the radial distance C between the first communication holes 42a adjacent to each other may be different from each other.

The flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g and the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f are different from each other. In the present embodiment, the flow path cross-sectional area of the first communication hole 42a that opens in the outer portion 16g and the flow path cross-sectional area of the first communication hole 42a that opens in the inner portion 16f are different from each other. The flow path cross-sectional area of each first communication hole 42a is the same over the entire length in the axial direction.
The flow path cross-sectional area of each first communication hole 42a may differ depending on the position in the axial direction. In this case, the flow path cross-sectional area of the first communication hole 42a can be represented by the average value of the flow path cross-sectional areas at a plurality of positions along the axial direction.

In the present embodiment, the flow path cross-sectional area of the first communication hole 42a that opens in the outer portion 16g is smaller than the flow path cross-sectional area of the first communication hole 42a that opens in the inner portion 16f. As a result, the flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g is higher than the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f.
Here, the thicknesses of the upper wall 33 and the lower wall 34 are the same over the entire area, and the flow path length of the first communication hole 42a that opens in the outer portion 16g and the first communication that opens in the inner portion 16f. The flow path length of the hole 42a is the same as that of the hole 42a.

In the vibration isolator 1 having such a configuration, when idle vibration having a relatively high frequency among low frequency vibrations is input in the axial direction, the movable member 41 is deformed or displaced in the accommodation chamber 42, and the liquid is liquid. This vibration is dampened and absorbed by the liquid in the chamber 19 flowing through the first communication hole 42a and the second communication hole 42b. Further, among the low frequency vibrations, when the shake vibration having a relatively low frequency is input in the axial direction, the liquid in the liquid chamber 19 flows through the orifice passage 24, and this vibration is attenuated and absorbed.

As described above, according to the vibration isolator 1 according to the present embodiment, the tubular member 21 projecting toward the elastic body 13 is arranged on the first wall surface 16b of the partition member 16, so that the shaft When the elastic body 13 is deformed in the secondary vibration mode in the vertical cross-sectional view along the axial direction due to the input of the medium frequency vibration in the direction, the node portion conventionally generated in the central portion of the elastic body 13 is formed. For example, due to the fact that the liquid between the inner peripheral surface of the main liquid chamber 14 and the outer peripheral surface of the upper portion of the tubular member 21 becomes difficult to flow, the liquid is displaced toward the second mounting member 12, which is an elastic body. In 13, the portion located on the first mounting member 11 side of the knot portion is more easily deformed than the portion located on the second mounting member 12 side of the knot portion. As a result, when the medium frequency vibration in the axial direction is input, the portion of the elastic body 13 located closer to the first mounting member 11 than the node portion is positively deformed, and the rigidity of the elastic body 13 is apparently reduced. It becomes possible to attenuate and absorb this vibration.

Further, since the plurality of first communication holes 42a are open to both the inner portion 16f and the outer portion 16g of the first wall surface 16b, it is possible to arrange many first communication holes 42a in the first wall surface 16b. Therefore, for example, idle vibration having a relatively high frequency among low frequency vibrations can be reliably attenuated and absorbed.

Further, the flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g and the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f are different from each other. It is possible to adjust the flow state of the liquid between the inner peripheral surface of the liquid chamber 14 and the outer peripheral surface of the upper portion of the tubular member 21, for example, the flow velocity, and the position of the node portion can be easily adjusted. Can be done.
Further, by designing the first communication hole 42a formed in the first wall surface 16b instead of the tubular member 21 protruding from the first wall surface 16b, the inner peripheral surface of the main liquid chamber 14 and the upper portion of the tubular member 21 are designed. Since it is possible to adjust the flow state of the liquid with the outer peripheral surface of the above, it is possible to make it less likely to cause design restrictions as compared with the case where the tubular member 21 is designed and the flow state is adjusted. it can.

Since the flow path cross-sectional area of the first communication hole 42a that opens in the outer portion 16g and the flow path cross-sectional area of the first communication hole 42a that opens in the inner portion 16f are different from each other, the former first communication hole 42a The flow resistance of the liquid flowing through the first communication hole 42a and the flow resistance of the liquid flowing through the first communication hole 42a can be surely different from each other.
Since the quantity of the first communication hole 42a opened in the outer portion 16g and the quantity of the first communication hole 42a opened in the inner portion 16f are different from each other, the inner peripheral surface of the main liquid chamber 14 and the tubular member 21 It becomes easy to adjust the flow state of the liquid with the outer peripheral surface of the upper part such as the flow velocity, and the position of the node portion can be easily adjusted.

Since the flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g is higher than the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f, the inner peripheral surface of the main liquid chamber 14 The liquid between the surface and the outer peripheral surface of the upper part of the tubular member 21 becomes less likely to flow, and the node portion can be reliably shifted to the second mounting member 12 side when the medium frequency vibration in the axial direction is input. Therefore, the medium frequency vibration can be reliably damped and absorbed.

Further, since the axial length of the tubular member 21 is 20% or more of the maximum axial height T of the main liquid chamber 14, it is possible to reliably attenuate and absorb the axial medium frequency vibration. Can be done.
Further, since the inner diameter of the tubular member 21 is more than half of the maximum inner diameter R of the main liquid chamber 14, it is possible to reliably attenuate and absorb the medium frequency vibration in the axial direction.

Next, the second embodiment according to the present invention will be described, but the basic configuration is the same as that of the first embodiment. Therefore, the same reference numerals are given to the same configurations, the description thereof will be omitted, and only the different points will be described.

In the vibration isolator 2 according to the present embodiment, as shown in FIG. 3, the flow path length of the first communication hole 42a opening in the outer portion 16g and the flow path of the first communication hole 42a opening in the inner portion 16f. The length and are different from each other. As a result, the flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g and the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f are different from each other.

In the present embodiment, the flow path length of the first communication hole 42a that opens in the outer portion 16g is longer than the flow path length of the first communication hole 42a that opens in the inner portion 16f. As a result, the flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g is higher than the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f.

In the illustrated example, in each of the upper wall 33 and the lower wall 34, the thickness of the outer peripheral portion is thicker than the thickness of the portion located inside in the radial direction from the outer peripheral portion. The lower surface of the upper wall 33 and the upper surface of the lower wall 34 are flat over the entire area. The outer peripheral portions of the upper wall 33 and the lower wall 34 have the same thickness. A tubular member 21 is arranged on the upper surface of the inner peripheral edge portion of the outer peripheral portion of the upper wall 33. The upper surface of the outer peripheral portion of the upper wall 33 is an outer portion 16 g.
From the above, the flow path length of the first communication hole 42a that opens in the outer portion 16g is longer than the flow path length of the first communication hole 42a that opens in the inner portion 16f.

As shown in FIG. 4, the flow path cross-sectional area of the first communication hole 42a opening in the outer portion 16g and the flow path cross-sectional area of the first communication hole 42a opening in the inner portion 16f are the same. There is.
For all of the plurality of first communication holes 42a opened in the first wall surface 16b, the intervals between the first communication holes 42a adjacent to each other are equal to each other and smaller than the inner diameter of the first communication holes 42a.

According to the vibration isolator 2 according to the present embodiment, the flow path length of the first communication hole 42a opening in the outer portion 16g and the flow path length of the first communication hole 42a opening in the inner portion 16f are different from each other. Therefore, the flow resistance of the liquid flowing through the first communication hole 42a of the former and the flow resistance of the liquid flowing through the first communication hole 42a of the latter can be surely made different from each other, and the first implementation can be performed. It has the same effect as that of the anti-vibration device 1 according to the embodiment.

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, the flow resistance of the liquid flowing through the first communication hole 42a opening in the outer portion 16g may be lower than the flow resistance of the liquid flowing through the first communication hole 42a opening in the inner portion 16f.
The flow path cross-sectional area of the first communication hole 42a that opens in the outer portion 16g may be larger than the flow path cross-sectional area of the first communication hole 42a that opens in the inner portion 16f.
The flow path length of the first communication hole 42a that opens in the outer portion 16g may be shorter than the flow path length of the first communication hole 42a that opens in the inner portion 16f.
The quantity of the first communication hole 42a that opens in the outer portion 16g may be equal to or greater than the quantity of the first communication hole 42a that opens in the inner portion 16f.
The ratio of the opening area of the first communication hole 42a to the flat area of the outer portion 16g may be equal to or greater than the ratio of the opening area of the first communication hole 42a to the flat area of the inner portion 16f.
In the above embodiment, the total opening area of the first communication hole 42a opening in the inner portion 16f is made larger than the total opening area of the first communication hole 42a opening in the outer portion 16g, but the present invention is not limited to this. The total opening area of the first communication hole 42a that opens in the inner portion 16f may be equal to or less than the total opening area of the first communication hole 42a that opens in the outer portion 16g.

Further, although the tubular member 21 is connected to the first wall surface 16b so as not to overlap the first communication hole 42a, the tubular member 21 is connected to the first wall surface 16b so as not to overlap the first communication hole 42a. May be overlapped with and connected.
Further, although the elastic body 13 has a structure formed in a tubular shape extending in the axial direction, a structure formed in an annular plate shape having upper and lower surfaces may be adopted.
Further, although the recessed portion is formed on the upper wall surface of the partition member 16, the recessed portion does not have to be formed.

Further, in the above-described embodiment, the compression type anti-vibration devices 1 and 2 in which a positive pressure acts on the main liquid chamber 14 by the action of a supporting load have been described, but the main liquid chamber 14 is located on the lower side in the vertical direction. In addition, 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 when a supporting load acts.

Further, the anti-vibration devices 1 and 2 according to the present invention are 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 possible to replace the constituent elements in the above-described embodiment with well-known constituent elements as appropriate without departing from the spirit of the present invention, and the above-described embodiments and modifications may be appropriately combined.

1, 2 Anti-vibration device 11 1st mounting member 12 2nd mounting member 13 Elastic body 14 Main liquid chamber 15 Secondary liquid chamber 16 Partition member 16b 1st wall surface 16f Inner part 16g Outer part 19 Liquid chamber 21 Cylindrical member 24 Orifice passage 41 Movable member 42 Storage chamber 42a 1st communication hole 42b 2nd communication hole O Central axis

Claims (5)

A tubular 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 that partitions the liquid chamber in the first mounting member in which the liquid is sealed into a main liquid chamber and a sub liquid chamber having the elastic body as a part of the partition wall in the axial direction along the central axis of the first mounting member. Members and
A movable member that is deformably or displaceably housed in a storage chamber provided in the partition member is provided.
The partition member includes an orifice passage that communicates the main liquid chamber and the sub liquid chamber, a plurality of first communication holes that communicate the main liquid chamber and the accommodating chamber, and the sub liquid chamber and the accommodating chamber. A second communication hole, which communicates with, is formed.
In the partition member, a tubular member that protrudes in the axial direction toward the elastic body is arranged on the first wall surface that has the first communication hole opened and forms a part of the inner surface of the main liquid chamber. Being done
The plurality of first communication holes are opened in both the inner portion located inside the tubular member and the outer portion located outside the tubular member on the first wall surface.
A vibration isolator in which the flow resistance of the liquid flowing through the first communication hole opened in the outer portion and the flow resistance of the liquid flowing through the first communication hole opened in the inner portion are different from each other. The vibration isolation according to claim 1, wherein the flow path cross-sectional area of the first communication hole that opens in the outer portion and the flow path cross-sectional area of the first communication hole that opens in the inner portion are different from each other. apparatus. The vibration isolation according to claim 1 or 2, wherein the flow path length of the first communication hole opened in the outer portion and the flow path length of the first communication hole opened in the inner portion are different from each other. apparatus. The prevention according to any one of claims 1 to 3, wherein the quantity of the first communication hole opened in the outer portion and the quantity of the first communication hole opened in the inner portion are different from each other. Shaking device. Any one of claims 1 to 4, wherein the flow resistance of the liquid flowing through the first communication hole opened in the outer portion is higher than the flow resistance of the liquid flowing through the first communication hole opened in the inner portion. The anti-vibration device described in the section.

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