JP6889645B2 - 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 absorbs and attenuates the vibration of a vibration generating portion of an engine or the like.

Conventionally, for example, the vibration isolator described in Patent Document 1 below has been known. This vibration isolator includes a tubular first mounting member connected to one of a vibration generating portion and a vibration receiving portion, a second mounting member connected to the other, a first mounting member, and a second. It is provided with an elastic body connected to the mounting member and a partition member for partitioning the liquid chamber in the first mounting member into a main liquid chamber and a sub liquid chamber having the elastic body as a part of a partition wall. The partition member consists of a membrane that forms a part of the partition wall of the main liquid chamber, an intermediate chamber that is located on the opposite side of the main liquid chamber across the membrane and has a membrane as a part of the partition wall, and a main liquid chamber and an intermediate chamber. It includes a first orifice passage that communicates with the intermediate chamber and a second orifice passage that communicates the intermediate chamber and the auxiliary liquid chamber.

Japanese Unexamined Patent Publication No. 2007-85523

However, in the conventional anti-vibration device, the damping force generated when the bound load for flowing the liquid from the main liquid chamber toward the sub liquid chamber side is input, and the liquid is circulated from the sub liquid chamber toward the main liquid chamber side. It was not possible to make the damping force generated when the rebound load was input different.

The present invention has been made in view of the above-mentioned circumstances, and provides an anti-vibration device capable of differentiating the damping force generated when a bound load is input and the damping force generated when a rebound load is input. With the goal.

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 the first mounting. An elastic body connecting the member and the second mounting member, and a partition member for partitioning the liquid chamber in the first mounting member into a main liquid chamber and a sub liquid chamber having the elastic body as a part of a partition wall. The partition member includes a membrane that forms a part of a partition wall of the main liquid chamber, an intermediate chamber that is located on the opposite side of the main liquid chamber with the membrane sandwiched therein and has the membrane as a part of the partition wall, and the partition member. A first orifice passage connecting the main liquid chamber and the intermediate chamber and a second orifice passage communicating the intermediate chamber and the auxiliary liquid chamber are provided, and the membrane is expanded toward the intermediate chamber side. It is characterized by comprising a restraining member for suppressing either one of the bulging deformation and the bulging deformation toward the main liquid chamber side.

According to the present invention, when the restraining member suppresses the bulging deformation toward the intermediate chamber side of the membrane, the vibration isolator has a bound load that allows the liquid to flow from the main liquid chamber to the auxiliary liquid chamber side. When a positive pressure is applied to the main liquid chamber when it is input, the membrane is prevented from bulging and deforming toward the intermediate chamber side, so the positive pressure in the main liquid chamber is not relaxed and a high damping force is generated. Can be made to. In this case, when a rebound load that allows the liquid to flow from the auxiliary liquid chamber to the main liquid chamber side is input to the vibration isolator, the restraining member does not suppress the deformation of the membrane, and the membrane is the main liquid chamber. By smoothly bulging and deforming toward the side, an increase in damping force is suppressed.
Further, since the partition member includes an intermediate chamber having the membrane as a part of the partition wall, the membrane is provided when the liquid in the main liquid chamber flows into the intermediate chamber through the first orifice passage at the time of inputting the bound load. It will be elastically deformed so as to bulge toward the main liquid chamber side. Therefore, the flow velocity is reduced until the liquid in the main liquid chamber flows into the second orifice passage, and a high damping force can be generated when the bound load is input.
From the above, the damping force generated when the bound load is input can be made higher than the damping force generated when the rebound load is input.

On the other hand, when the restraining member suppresses the bulging deformation toward the main liquid chamber side of the membrane, when a rebound load is input to this vibration isolator and a negative pressure acts on the main liquid chamber, the membrane becomes the main liquid. Since the bulging deformation toward the chamber side is suppressed, the negative pressure in the main liquid chamber is not relaxed, and a high damping force can be generated. In this case, when a bound load is input to the anti-vibration device, the deterrent member does not suppress the deformation of the membrane, and the membrane smoothly bulges and deforms toward the intermediate chamber side, so that the damping force increases. Is suppressed.
Further, since the partition member is provided with an intermediate chamber, when the liquid in the auxiliary liquid chamber flows into the intermediate chamber when the rebound load is input, the second orifice passage of the wall surface defining the auxiliary liquid chamber is provided. It will collide with the opened surface, and the flow velocity will be reduced until the liquid in the auxiliary liquid chamber flows into the first orifice passage, and a high damping force can be generated when the rebound load is input. ..
From the above, the damping force generated when the rebound load is input can be made higher than the damping force generated when the rebound load is input.

Here, the restraining member suppresses the bulging deformation of the membrane toward the intermediate chamber side, and the liquid flow resistance in the portion of the first orifice passage located on the main liquid chamber side is increased. It may be higher than the flow resistance of the liquid in the portion located on the intermediate chamber side.

In this case, the liquid flow resistance in the portion of the first orifice passage connecting the main liquid chamber and the intermediate chamber, which is located on the main liquid chamber side (hereinafter, the main liquid chamber side portion), is located on the intermediate chamber side. Since it is higher than the flow resistance of the liquid in the portion (hereinafter referred to as the intermediate chamber side portion), when the liquid in the main liquid chamber flows into the main liquid chamber side portion of the first orifice passage at the time of inputting the bound load, the said Greater resistance is provided as compared to the case where the liquid flows directly into the intermediate chamber side portion. As a result, a high damping force can be generated when a bound load is input.
On the other hand, when the liquid on the auxiliary liquid chamber side flows through the first orifice passage toward the main liquid chamber, even if the flow resistances of the main liquid chamber side portion and the intermediate chamber side portion are different from each other, both Since they form one orifice passage continuous with each other, it is possible to suppress the resistance generated when the liquid passes through the boundary portion thereof, and it is possible to suppress the damping force generated when the rebound load is input. it can.
Further, since the restraining member suppresses the bulging deformation of the membrane toward the intermediate chamber side, a high damping force can be generated when the bound load is input, as described above.
From the above, it is possible to surely increase the damping force generated when the bound load is input from the damping force generated when the rebound load is input, increase the difference between these two damping forces, and increase the damping force generated when the rebound load is input. It is possible to increase the ratio of the damping force generated when the bound load is input to.
Furthermore, even if the main liquid chamber suddenly becomes negative pressure due to the input of a large rebound load, the membrane bulges and deforms toward the main liquid chamber side, so that the negative pressure in the main liquid chamber can be suppressed. Since it can be done, it is possible to suppress the occurrence of cavitation.
Further, for each of these effects, for example, a member that operates when the hydraulic pressure in the main liquid chamber reaches a predetermined value is not adopted, and the flow resistance of the liquid in the main liquid chamber side portion as described above is increased. It is a vibration with a relatively small amplitude because it is higher than the flow resistance of the liquid in the intermediate chamber side portion and is played by the configuration in which the membrane forms a part of the partition wall of both the main liquid chamber and the intermediate chamber. However, the above-mentioned effects can be stably and accurately achieved.

In this configuration, the opening direction in which the first orifice passage opens toward the intermediate chamber may intersect with the opening direction in which the second orifice passage opens toward the intermediate chamber.

In this case, it is possible to prevent the liquid from the main liquid chamber side that has flowed into the intermediate chamber from going straight toward the second orifice passage, and this liquid can be diffused in the intermediate chamber. As a result, the flow velocity of the liquid in the main liquid chamber is reduced more reliably until it flows into the second orifice passage.

Further, the cross-sectional area of the intermediate chamber along the direction orthogonal to the opening direction in which the second orifice passage opens toward the intermediate chamber may be larger than the flow path cross-sectional area of the second orifice passage.

In this case, since the cross-sectional area of the intermediate chamber is larger than the flow path cross-sectional area of the second orifice passage, it is possible to increase the resistance generated when the liquid in the intermediate chamber flows into the second orifice passage. , The damping force generated when the bound load is input can be surely increased.

Further, the portion of the first orifice passage on the main liquid chamber side may be a passage having a flow path length longer than the flow path diameter.

In this case, since the main liquid chamber side portion of the first orifice passage is a passage whose flow path length is longer than the flow path diameter, the resistance given to the liquid from the main liquid chamber side flowing through this portion is increased. It can be increased more reliably.

Here, the restraining member suppresses the swelling deformation of the membrane toward the main liquid chamber side, and the liquid flow resistance in the portion of the first orifice passage located on the intermediate chamber side is increased. It may be higher than the flow resistance of the liquid in the portion located on the main liquid chamber side.

In this case, since the liquid flow resistance in the intermediate chamber side portion is higher than the liquid flow resistance in the main liquid chamber side portion, the liquid in the auxiliary liquid chamber passes through the second orifice passage in the intermediate chamber when the rebound load is input. When the liquid flows into the intermediate chamber side portion of the first orifice passage after flowing into the main liquid chamber side portion, a large resistance is imparted as compared with the case where the liquid flows directly into the main liquid chamber side portion. As a result, a high damping force can be generated when the rebound load is input.
On the other hand, when the liquid in the main liquid chamber flows through the first orifice passage toward the auxiliary liquid chamber side, even if the flow resistances of the main liquid chamber side portion and the intermediate chamber side portion are different from each other, both Since they form one orifice passage continuous with each other, it is possible to suppress the resistance generated when the liquid passes through the boundary portion thereof, and it is possible to suppress the damping force generated when the bound load is input. it can.
Further, since the restraining member suppresses the bulging deformation of the membrane toward the main liquid chamber side, a high damping force can be generated when the rebound load is input, as described above.
From the above, it is possible to surely increase the damping force generated when the rebound load is input from the damping force generated when the bound load is input, increase the difference between these two damping forces, and increase the damping force generated when the bound load is input. It is possible to increase the ratio of the damping force generated when the rebound load is input to.
Further, for each of these actions and effects, for example, a member that operates when the hydraulic pressure in the main liquid chamber reaches a predetermined value is not adopted, and the liquid flow resistance in the intermediate chamber side portion as described above is reduced. It is a vibration with a relatively small amplitude because it is higher than the flow resistance of the liquid in the main liquid chamber side portion and is played by the configuration in which the membrane forms a part of the partition wall of both the main liquid chamber and the intermediate chamber. However, the above-mentioned effects can be stably and accurately achieved.

In this configuration, the cross-sectional area of the intermediate chamber along the direction orthogonal to the opening direction in which the second orifice passage opens toward the intermediate chamber is the flow of the portion of the first orifice passage on the intermediate chamber side. It may be larger than the road cross-sectional area.

In this case, since the cross-sectional area of the intermediate chamber is larger than the flow path cross-sectional area of the intermediate chamber side portion of the first orifice passage, the liquid in the intermediate chamber flows into the intermediate chamber side portion of the first orifice passage. It is possible to surely increase the resistance generated when the rebound load is input, and it is possible to surely increase the damping force generated when the rebound load is input.

Further, the portion of the first orifice passage on the intermediate chamber side may be a passage having a flow path length longer than the flow path diameter.

In this case, since the intermediate chamber side portion of the first orifice passage is a passage whose channel length is longer than the channel diameter, the resistance given to the liquid from the auxiliary liquid chamber side flowing through this portion is further increased. It can definitely be increased.

According to the present invention, the damping force generated when the bound load is input and the damping force generated when the rebound load is input can be made different.

It is a vertical sectional view of the vibration isolation device which concerns on 1st Embodiment of this invention. It is a schematic diagram of the anti-vibration device shown in FIG. It is a vertical sectional view of the vibration isolation device which concerns on 2nd Embodiment of this invention. It is a schematic diagram of the vibration isolation device shown in FIG.

Hereinafter, the vibration isolator according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the vibration isolator 1 has a tubular first mounting member 11 connected to one of a vibration generating portion and a vibration receiving portion, and a second mounting member 12 connected to the other. The elastic body 13 connecting the first mounting member 11 and the second mounting member 12, the liquid chamber 14 in the first mounting member 11, the main liquid chamber 15 in which the elastic body 13 is a part of the partition wall, and A partition member 17 for partitioning the auxiliary liquid chamber 16 is provided. In the illustrated example, the partition member 17 partitions the liquid chamber 14 in the axial direction along the central axis O of the first mounting member 11.
When this vibration isolator 1 is used, for example, as an engine mount for an automobile, the first mounting member 11 is connected to the vehicle body as a vibration receiving portion, and the second mounting member 12 is connected to the engine as a vibration generating portion. .. As a result, the vibration of the engine is suppressed from being transmitted to the vehicle body.

Hereinafter, the main liquid chamber 15 side along the axial direction with respect to the partition member 17 is referred to as an upper side, and the sub liquid chamber 16 side is referred to as a lower side. Further, in a plan view of the vibration isolator 1 from the axial direction, the direction orthogonal to the central axis O is referred to as the radial direction, and the direction orbiting around the central axis O is referred to as the circumferential direction.

The first mounting member 11 is formed in a bottomed tubular shape. The bottom of the first mounting member 11 is formed in an annular shape and is arranged coaxially with the central axis O. The inner peripheral surface of the lower portion of the first mounting member 11 is covered with a covering rubber integrally formed with the elastic body 13.
The front and back surfaces of the second mounting member 12 are formed in a flat plate shape orthogonal to the central axis O. The second mounting member 12 is formed in a disk shape, for example, and is arranged coaxially with the central axis O. The second mounting member 12 is arranged above the first mounting member 11. The outer diameter of the second mounting member 12 is the same as the inner diameter of the first mounting member 11.

The elastic body 13 connects the inner peripheral surface of the upper portion of the first mounting member 11 and the lower surface of the second mounting member 12. The upper end opening of the first mounting member 11 is sealed by the elastic body 13. The elastic body 13 is vulcanized and adhered to the first mounting member 11 and the second mounting member 12. The elastic body 13 is formed in a humpback tubular shape and is arranged coaxially with the central axis O. Of the elastic body 13, the top wall portion is connected to the second mounting member 12, and the lower end portion of the peripheral wall portion is connected to the first mounting member 11. The peripheral wall portion of the elastic body 13 gradually extends outward in the radial direction from the upper side to the lower side.

The diaphragm ring 18 is liquid-tightly fitted into the lower end portion of the first mounting member 11 via the covering rubber. The diaphragm ring 18 is formed in a double tubular shape and is arranged coaxially with the central axis O. The outer peripheral portion of the diaphragm 19 formed so as to be elastically deformable by rubber or the like is vulcanized and adhered to the diaphragm ring 18. Of the diaphragm ring 18, the outer cylinder portion is fitted in the first mounting member 11, and the inner cylinder portion is embedded in the diaphragm 19. The diaphragm 19 is vulcanized and adhered to the inner peripheral surface of the outer cylinder portion of the diaphragm ring 18. The diaphragm 19 expands and contracts with the inflow and outflow of the liquid into the auxiliary liquid chamber 16.
The liquid chamber 14 in which the liquid is sealed is defined in the first mounting member 11 by the diaphragm 19 and the elastic body 13. As the liquid sealed in the liquid chamber 14, for example, water or ethylene glycol can be used.

The front and back surfaces of the partition member 17 are formed in a disk shape orthogonal to the central axis O, and are fitted into the first mounting member 11 via the covering rubber. The liquid chamber 14 in the first mounting member 11 is defined by the partition member 17, the main liquid chamber 15 defined by the elastic body 13 and the partition member 17, and the auxiliary liquid defined by the diaphragm 19 and the partition member 17. It is divided into rooms 16.

The partition member 17 closes the tubular main body member 34 fitted in the first mounting member 11 via the covering rubber and the upper end opening of the main body member 34, and is a part of the partition wall of the main liquid chamber 15. A membrane 31 forming a structure, a lower member 33 that closes the lower end opening of the main body member 34, and an intermediate chamber 35 that is located on the opposite side of the main liquid chamber 15 across the membrane 31 and has the membrane 31 as a part of the partition wall. , The annular fixing member 38 that fixes the rubber 31 to the main body member 34, the first orifice passage 21 that communicates the main liquid chamber 15 and the intermediate chamber 35, and the second that communicates the intermediate chamber 35 and the auxiliary liquid chamber 16. It includes an orifice passage 22 and.

The membrane 31 is formed in a disk shape by an elastic material such as rubber. The membrane 31 is arranged coaxially with the central axis O. The volume of the membrane 31 is smaller than the volume of the elastic body 13.
The main body member 34 includes a main body ring 23 fitted in the first mounting member 11, an outer flange portion 24 protruding inward in the radial direction from the upper end portion of the main body ring 23, and a lower end portion of the outer flange portion 24. It is provided with an inner flange portion 25 that protrudes inward in the radial direction from the inside. The main body ring 23, the outer flange portion 24, and the inner flange portion 25 are arranged coaxially with the central axis O. The lower surfaces of the outer flange portion 24 and the inner flange portion 25 are flush with each other.

The membrane 31 is fitted in the outer flange portion 24. The inner flange portion 25 supports the outer peripheral edge portion on the lower surface of the membrane 31. The membrane 31 projects above the upper surface of the outer flange portion 24. The outer peripheral edge portion on the upper surface of the membrane 31 is supported by the fixing member 38, and the outer peripheral edge portion of the membrane 31 is fixed by being sandwiched in the axial direction by the fixing member 38 and the inner flange portion 25. Therefore, the membrane 31 is supported so as to be elastically deformable in the axial direction with the outer peripheral edge portion as a fixed end. The fixing member 38 is arranged coaxially with the central axis O, the outer peripheral portion of the fixing member 38 is arranged on the upper surface of the outer flange portion 24, and the inner peripheral portion supports the upper surface of the membrane 31.

A first orifice groove 23a that opens outward in the radial direction and extends in the circumferential direction is formed on the outer peripheral surface of the main body ring 23 of the main body member 34. The radial outer opening of the first orifice groove 23a is closed by the covering rubber. A first communication hole 23b that communicates the main liquid chamber 15 and the first orifice groove 23a is formed on the upper surface of the main body ring 23. The first communication hole 23b communicates the main liquid chamber 15 and the first orifice groove 23a in the axial direction.
The first orifice groove 23a extends in the circumferential direction from the first communication hole 23b over an angle range exceeding 180 ° toward one side in the circumferential direction about the central axis O.

The lower member 33 is formed in a bottomed tubular shape and is arranged coaxially with the central axis O. The lower member 33 is liquid-tightly fitted in the main body ring 23 of the main body member 34. The bottom wall portion of the lower member 33 forms a partition wall that axially partitions the auxiliary liquid chamber 16 and the intermediate chamber 35. The upper end opening edge of the peripheral wall portion of the lower member 33 is integrally in contact with the lower surfaces of the outer flange portion 24 and the inner flange portion 25 of the main body member 34. The upper surface of the bottom wall portion of the lower member 33 is separated downward from the lower surface of the membrane 31. The above-mentioned intermediate chamber 35 is defined by the upper surface of the bottom wall portion of the lower member 33, the inner peripheral surface of the peripheral wall portion, and the lower surface of the membrane 31. The intermediate chamber 35 and the main liquid chamber 15 are axially partitioned by the membrane 31. The internal volume of the intermediate chamber 35 is smaller than the internal volume of the main liquid chamber 15.

A second orifice groove 33a that opens outward in the radial direction and extends in the circumferential direction is formed on the outer peripheral surface of the peripheral wall portion of the lower member 33. The radial outer opening of the second orifice groove 33a is closed by the inner peripheral surface of the main body ring 23. A second communication hole 33b that communicates the second orifice groove 33a and the intermediate chamber 35 is formed on the inner peripheral surface of the peripheral wall portion of the lower member 33. The second communication hole 33b communicates the second orifice groove 33a with the intermediate chamber 35 in the radial direction.
The second orifice groove 33a extends in the circumferential direction from the second communication hole 33b over an angle range exceeding 180 ° toward one side in the circumferential direction about the central axis O. One end in the circumferential direction of each of the second orifice groove 33a and the first orifice groove 23a is arranged at the same position in the circumferential direction.

The auxiliary liquid chamber 16 is defined by the lower surface of the bottom wall portion of the lower member 33 and the diaphragm 19. A second orifice passage 22 that communicates the auxiliary liquid chamber 16 and the intermediate chamber 35 is formed in the bottom wall portion of the lower member 33. The second orifice passage 22 communicates the auxiliary liquid chamber 16 and the intermediate chamber 35 in the axial direction. The opening on the intermediate chamber 35 side of the second orifice passage 22 faces the membrane 31. The second orifice passage 22 is a through hole formed in the bottom wall portion of the lower member 33, and a plurality of the second orifice passages 22 are formed in the bottom wall portion of the lower member 33. All of these second orifice passages 22 are axially opposed to the membrane 31.

On the lower surface of the bottom wall portion of the lower member 33, the above-mentioned diaphragm ring 18 is arranged on the outer peripheral edge portion located on the outer side in the radial direction from the plurality of second orifice passages 22. The diaphragm ring 18 is integrally formed with the lower member 33. Of the diaphragm ring 18, the portion located on the outer side in the radial direction from the inner cylinder portion is located on the outer side in the radial direction from the lower member 33, and the main body ring is placed on the upper surface of the connecting portion between the outer cylinder portion and the inner cylinder portion. The lower surface of 23 is in liquid-tight contact.

The flow path cross-sectional area and the flow path length of each of the second orifice passages 22 are smaller than the flow path cross-sectional area and the flow path length of the first orifice passage 21 described later, respectively. The length of the second orifice passage 22 is smaller than the inner diameter. The length of the second orifice passage 22 may be equal to or greater than the inner diameter. The liquid flow resistance in each second orifice passage 22 is smaller than the liquid flow resistance in the first orifice passage 21.

Here, a connection hole 21c that communicates the first orifice groove 23a and the second orifice groove 33a is formed on the inner peripheral surface of the main body ring 23. The connection hole 21c communicates the first orifice groove 23a and the second orifice groove 33a in the radial direction. The first orifice passage 21 that communicates the main liquid chamber 15 and the intermediate chamber 35 has a first orifice groove 23a whose radial outer opening is closed by the covering rubber and a main body whose radial outer opening is closed. It is composed of a second orifice groove 33a closed by the inner peripheral surface of the ring 23 and a connection hole 21c.
Hereinafter, of the first orifice passage 21, the portion located on the main liquid chamber 15 side and defined by the first orifice groove 23a is referred to as the main liquid chamber side portion 21a, and is located on the intermediate chamber 35 side and is the second portion. The portion defined by the orifice groove 33a is referred to as an intermediate chamber side portion 21b.

Here, the connection hole 21c connects one end of the first orifice groove 23a in the circumferential direction and one end of the second orifice groove 33a in the circumferential direction. As a result, in the process in which the liquid flows from one of the main liquid chamber side portion 21a and the intermediate chamber side portion 21b into one of the other through the connection hole 21c and flows through the other, the liquid flowing through the one of the main liquid chamber side portion 21a and the intermediate chamber side portion 21b. The flow direction and the flow direction of the liquid flowing through the other are opposite to each other in the circumferential direction.

Further, in the present embodiment, the deterrent member 26 for suppressing the bulging deformation of the membrane 31 toward the intermediate chamber 35 side is arranged. The restraining member 26 is arranged on the partition member 17. The restraining member 26 is formed in a columnar shape erected upward from the bottom wall portion of the lower member 33. The lower surface of the membrane 31 is in contact with or close to the upper end surface of the restraining member 26. In the illustrated example, the membrane 31 is in contact with the upper end surface of the deterrent member 26 in a state where no upward pressing force is applied from the deterrent member 26. In this case, and when the lower surface of the membrane 31 is close to the upper end surface of the restraining member 26, the membrane 31 smoothly swells toward the main liquid chamber 15 side with a small force when the rebound load is input. It can be deformed, and an increase in damping force can be reliably prevented. The restraining member 26 is in contact with or close to the radial central portion of the membrane 31.

The restraining member 26 may be formed in a tubular shape, for example, may come into contact with a portion of the membrane 31 that is separated from the central portion in the radial direction, or may hit the lower surface of the membrane 31 over the entire area. It may be formed in a plate shape that is in contact with each other, and is not limited to the above-described embodiment and may be appropriately changed.
The restraining member 26 may be appropriately changed, for example, by disposing it on the first mounting member 11. For example, the restraining member 26 may be integrally formed of the same material as the membrane 31.
The restraining member 26 may come into contact with the membrane 31 in a state where an upward pressing force is applied.

Further, in the present embodiment, the liquid flow resistance in the main liquid chamber side portion 21a is higher than the liquid flow resistance in the intermediate chamber side portion 21b.
In the illustrated example, the flow path cross-sectional area of the main liquid chamber side portion 21a is smaller than the flow path cross-sectional area of the intermediate chamber side portion 21b. The opening area of the connection hole 21c is smaller than the flow path cross-sectional area of the main liquid chamber side portion 21a. The flow path length of the connection hole 21c is shorter than the flow path lengths of the main liquid chamber side portion 21a and the intermediate chamber side portion 21b.
In the vertical cross-sectional view of the first orifice passage 21, the axial length of the intermediate chamber side portion 21b is the radial length of the intermediate chamber side portion 21b and the axial length of the main liquid chamber side portion 21a. Is equivalent to. In the vertical cross-sectional view of the first orifice passage 21, the radial length of the main liquid chamber side portion 21a is shorter than the axial length of the main liquid chamber side portion 21a.

Here, the flow resistances of the main liquid chamber side portion 21a and the first communication hole 23b may be equal to each other or different from each other.
For example, when the flow resistance of the main liquid chamber side portion 21a is higher than the flow resistance of the first communication hole 23b, the flow resistance of the liquid when it passes through the first communication hole 23b and enters the main liquid chamber side portion 21a is high. A high damping force is generated at the time of input of the bound load which increases and circulates the liquid from the main liquid chamber 15 toward the sub liquid chamber 16 side.

Further, the flow resistances of the connection hole 21c and the main liquid chamber side portion 21a may be equal to each other or different from each other.
For example, when the flow resistance of the connection hole 21c is higher than the flow resistance of the main liquid chamber side portion 21a, the flow resistance of the liquid when it passes through the main liquid chamber side portion 21a and enters the connection hole 21c increases and bounces. A high damping force is generated when the load is input.

Further, the flow resistances of the intermediate chamber side portion 21b and the connection hole 21c may be equal to each other or different from each other.
For example, when the flow resistance of the intermediate chamber side portion 21b is higher than the flow resistance of the connection hole 21c, the flow resistance of the liquid when it passes through the connection hole 21c and enters the intermediate chamber side portion 21b increases, and the bound load increases. High damping force is generated at the time of input.

Further, the flow resistances of the second communication hole 33b and the intermediate chamber side portion 21b may be equal to each other or different from each other.
For example, when the flow resistance of the second communication hole 33b is higher than the flow resistance of the intermediate chamber side portion 21b, the flow resistance of the liquid when it passes through the intermediate chamber side portion 21b and enters the second communication hole 33b increases. , A high damping force is generated when the bound load is input.

Further, in the present embodiment, the opening direction in which the first orifice passage 21 opens toward the intermediate chamber 35, that is, the opening direction in which the second communication hole 33b faces the intermediate chamber 35, and the second orifice passage 22 in the intermediate chamber 35. It intersects with the opening direction that opens toward. In the illustrated example, the second communication hole 33b opens radially toward the intermediate chamber 35, and the second orifice passage 22 opens axially toward the intermediate chamber 35. That is, the opening direction of the second communication hole 33b toward the intermediate chamber 35 is orthogonal to the opening direction of the second orifice passage 22 toward the intermediate chamber 35.

Further, in the present embodiment, the cross-sectional area of the intermediate chamber 35 along the direction orthogonal to the opening direction in which the second orifice passage 22 opens toward the intermediate chamber 35 is the flow path cross-sectional area of the second orifice passage 22. It is larger than the flow path cross-sectional area of the intermediate chamber side portion 21b of the 1 orifice passage 21 and the flow path cross-sectional area of the main liquid chamber side portion 21a of the first orifice passage 21.
Further, in the present embodiment, the main liquid chamber side portion 21a and the intermediate chamber side portion 21b are passages having a flow path length longer than the flow path diameter. Here, in the illustrated example, the flow path cross-sectional shape of the first orifice passage 21 is rectangular, and in this case, the flow path diameter is changed from the flow path cross-sectional shape to a circular shape having the same flow path cross-sectional area. It can be represented by the diameter of this circular shape when replaced.

As described above, according to the anti-vibration device 1 according to the present embodiment, since the deterrent member 26 for suppressing the bulging deformation toward the intermediate chamber 35 side of the membrane 31 is provided, the liquid is subordinated from the main liquid chamber 15. When a bound load to be circulated toward the liquid chamber 16 side is input and a positive pressure acts on the main liquid chamber 15, the membrane 31 is prevented from bulging and deforming toward the intermediate chamber 35 side. The positive pressure of the liquid chamber 15 is not relaxed, and a high damping force can be generated.
On the other hand, when a rebound load for circulating the liquid from the auxiliary liquid chamber 16 toward the main liquid chamber 15 is input to the vibration isolator 1, the restraining member 26 does not suppress the deformation of the membrane 31 and the membrane 31 is not restrained. The 31 is smoothly bulged and deformed toward the main liquid chamber 15 side, so that the increase in the damping force is suppressed.

Further, since the partition member 17 includes an intermediate chamber 35 having the membrane 31 as a part of the partition wall, the liquid in the main liquid chamber 15 flows into the intermediate chamber 35 through the first orifice passage 21 when the bound load is input. At that time, the membrane 31 is elastically deformed so as to bulge toward the main liquid chamber 15. Therefore, the flow velocity is reduced until the liquid in the main liquid chamber 15 flows into the second orifice passage 22, and a high damping force can be generated when the bound load is input.
From the above, the damping force generated when the bound load is input can be made higher than the damping force generated when the rebound load is input.

Further, in the first orifice passage 21 that communicates the main liquid chamber 15 and the intermediate chamber 35, the liquid flow resistance in the main liquid chamber side portion 21a is higher than the liquid flow resistance in the intermediate chamber side portion 21b, so that it bounces. When the liquid in the main liquid chamber 15 flows into the main liquid chamber side portion 21a of the first orifice passage 21 at the time of inputting the load, a large resistance is imparted as compared with the case where the liquid flows directly into the intermediate chamber side portion 21b. The liquid. As a result, a high damping force can be generated when a bound load is input.
On the other hand, when the liquid on the auxiliary liquid chamber 16 side flows through the first orifice passage 21 toward the main liquid chamber 15, it is assumed that the flow resistances of the main liquid chamber side portion 21a and the intermediate chamber side portion 21b are different from each other. However, since both of them form one orifice passage continuously with each other, it is possible to suppress the resistance generated when the liquid passes through the boundary portion thereof, and suppress the damping force generated when the rebound load is input. can do.
From the above, it is possible to surely increase the damping force generated when the bound load is input from the damping force generated when the rebound load is input, increase the difference between these two damping forces, and increase the damping force generated when the rebound load is input. It is possible to increase the ratio of the damping force generated when the bound load is input to.

Further, even if the main liquid chamber 15 suddenly becomes negative pressure due to the input of a large rebound load, the membrane 31 bulges and deforms toward the main liquid chamber 15 side, so that the negative pressure of the main liquid chamber 15 is increased. Since it is possible to suppress the occurrence of cavitation, it is also possible to suppress the occurrence of cavitation.
Further, each of these effects does not employ, for example, a member that operates when the hydraulic pressure in the main liquid chamber 15 reaches a predetermined value, and the liquid flows in the main liquid chamber side portion 21a as described above. The resistance is higher than the flow resistance of the liquid in the intermediate chamber side portion 21b, and the membrane 31 is played by the configuration forming a part of the partition wall of both the main liquid chamber 15 and the intermediate chamber 35, so that the amplitude is relatively large. Even if the vibration is small, the above-mentioned action and effect can be stably and accurately performed.

Further, since the opening direction in which the first orifice passage 21 opens toward the intermediate chamber 35 intersects with the opening direction in which the second orifice passage 22 opens toward the intermediate chamber 35, the main flow into the intermediate chamber 35. It is possible to prevent the liquid from the liquid chamber 15 side from going straight toward the second orifice passage 22, and this liquid can be diffused in the intermediate chamber 35. As a result, the flow velocity of the liquid in the main liquid chamber 15 is surely reduced until it flows into the second orifice passage 22.

Further, since the cross-sectional area of the intermediate chamber 35 is larger than the flow path cross-sectional area of the second orifice passage 22, the resistance generated when the liquid in the intermediate chamber 35 flows into the second orifice passage 22 can be increased. This makes it possible to reliably increase the damping force generated when a bound load is input.
Further, since the main liquid chamber side portion 21a of the first orifice passage 21 is a passage whose flow path length is longer than the flow path diameter, the resistance given to the liquid from the main liquid chamber 15 side flowing through this portion is increased. It can be enhanced even more reliably.

Next, the vibration isolator according to the second embodiment of the present invention will be described with reference to FIGS. 3 and 4.
In the second embodiment, the same parts as the components in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and only the different points will be described.

The diaphragm ring 28 is formed in an eclipsed tubular shape having an annular top wall portion, and is arranged coaxially with the central axis O. On the top wall portion of the diaphragm ring 28, a tubular body that projects downward and is arranged coaxially with the central axis O is formed. The outer peripheral portion of the diaphragm 19 is vulcanized and bonded to the inner surface of the diaphragm ring 28. The tubular body of the diaphragm ring 28 is embedded in the diaphragm 19.

The upper surface of the top wall portion of the diaphragm ring 28 is in liquidtight contact with the lower surface of the main body ring 23 of the partition member 17. The outer flange portion 24 of the partition member 17 projects upward from the inner peripheral edge portion on the upper surface of the main body ring 23. The inner peripheral surfaces of the outer flange portion 24 and the main body ring 23 are flush with each other. The upper end opening edge of the peripheral wall portion of the lower member 33 is in contact with the lower surface of the inner flange portion 25 of the main body member 34.

Further, in the present embodiment, a deterrent member 27 for suppressing the bulging deformation of the membrane 31 toward the main liquid chamber 15 side is arranged. The restraining member 27 is formed in a plate shape, and its outer peripheral edge portion is arranged on the inner peripheral portion of the fixing member 38. The restraining member 27 is formed with a plurality of through holes penetrating in the axial direction over the entire area. The upper surface of the membrane 31 is in contact with or close to the lower surface of the restraining member 27 over the entire area. In the illustrated example, the membrane 31 is in contact with the lower surface of the deterrent member 27 in a state where no downward pressing force is applied from the deterrent member 27.
The restraining member 27 may be formed in contact with or close to a part of the upper surface of the membrane 31, for example, in a columnar shape or a tubular shape, and may be appropriately changed without being limited to the above embodiment.
The restraining member 27 may be appropriately changed, for example, by arranging the restraining member 27 on the first mounting member 11.

Further, in the present embodiment, the liquid flow resistance in the intermediate chamber side portion 21b is higher than the liquid flow resistance in the main liquid chamber side portion 21a. In the illustrated example, the flow path cross-sectional area of the intermediate chamber side portion 21b is smaller than the flow path cross-sectional area of the main liquid chamber side portion 21a. Further, the opening area of the connection hole 21c is smaller than the flow path cross-sectional area of the intermediate chamber side portion 21b.
In the vertical cross-sectional view of the first orifice passage 21, the axial length of the intermediate chamber side portion 21b is longer than the radial length of the intermediate chamber side portion 21b, and the axial length of the main liquid chamber side portion 21a is long. It is equivalent to the length. In the vertical cross-sectional view of the first orifice passage 21, the radial length of the main liquid chamber side portion 21a is longer than the axial length of the main liquid chamber side portion 21a.

Here, the flow resistances of the intermediate chamber side portion 21b and the second communication hole 33b may be equal to each other or different from each other.
For example, when the flow resistance of the intermediate chamber side portion 21b is higher than the flow resistance of the second communication hole 33b, the flow resistance of the liquid when it passes through the second communication hole 33b and enters the intermediate chamber side portion 21b increases. , A high damping force is generated when the rebound load for flowing the liquid from the auxiliary liquid chamber 16 toward the main liquid chamber 15 side is input.

Further, the flow resistances of the connection hole 21c and the intermediate chamber side portion 21b may be equal to each other or different from each other.
For example, when the flow resistance of the connection hole 21c is higher than the flow resistance of the intermediate chamber side portion 21b, the flow resistance of the liquid when it passes through the intermediate chamber side portion 21b and enters the connection hole 21c increases, and the rebound load increases. High damping force is generated at the time of input.

Further, the flow resistances of the main liquid chamber side portion 21a and the connection hole 21c may be equal to each other or different from each other.
For example, when the flow resistance of the main liquid chamber side portion 21a is higher than the flow resistance of the connection hole 21c, the flow resistance of the liquid when it passes through the connection hole 21c and enters the main liquid chamber side portion 21a increases and rebounds. A high damping force is generated when the load is input.

Further, the flow resistances of the first communication hole 23b and the main liquid chamber side portion 21a may be equal to each other or different from each other.
For example, when the flow resistance of the first communication hole 23b is higher than the flow resistance of the main liquid chamber side portion 21a, the flow resistance of the liquid when it passes through the main liquid chamber side portion 21a and enters the first communication hole 23b is high. It increases and a high damping force is generated when the rebound load is input.

As described above, according to the anti-vibration device 2 according to the present embodiment, since the deterrent member 27 for suppressing the bulging deformation toward the main liquid chamber 15 side of the membrane 31 is provided, the rebound load is input and the main When a negative pressure acts on the liquid chamber 15, the membrane 31 is prevented from bulging and deforming toward the main liquid chamber 15, so that the negative pressure of the main liquid chamber 15 is not relaxed and a high damping force is applied. Can be generated.
On the other hand, when a bound load is input to the vibration isolator 2, the restraining member 27 does not suppress the deformation of the membrane 31, and the membrane 31 smoothly bulges and deforms toward the intermediate chamber 35 side. The increase in damping force is suppressed.

Further, since the partition member 17 includes the intermediate chamber 35, among the wall surfaces that define the auxiliary liquid chamber 16 when the liquid in the auxiliary liquid chamber 16 flows into the intermediate chamber 35 when the rebound load is input. The second orifice passage 22 collides with the opened surface, and the flow velocity is reduced until the liquid in the auxiliary liquid chamber 16 flows into the first orifice passage 21, which is high when the rebound load is input. A damping force can be generated.
From the above, the damping force generated when the rebound load is input can be made higher than the damping force generated when the rebound load is input.

Further, in the first orifice passage 21 that communicates the main liquid chamber 15 and the intermediate chamber 35, the liquid flow resistance in the intermediate chamber side portion 21b is higher than the liquid flow resistance in the main liquid chamber side portion 21a, so that the liquid rebounds. When the liquid in the auxiliary liquid chamber 16 flows into the intermediate chamber 35 through the second orifice passage 22 at the time of inputting the load and then flows into the intermediate chamber side portion 21b of the first orifice passage 21, the main liquid chamber side portion Greater resistance is imparted as compared to the case where it directly flows into 21a. As a result, a high damping force can be generated when the rebound load is input.
On the other hand, when the liquid in the main liquid chamber 15 flows through the first orifice passage 21 toward the auxiliary liquid chamber 16, it is assumed that the flow resistances of the main liquid chamber side portion 21a and the intermediate chamber side portion 21b are different from each other. However, since both of them form one orifice passage continuously with each other, it is possible to suppress the resistance generated when the liquid passes through the boundary portion thereof, and suppress the damping force generated when the bound load is input. can do.
From the above, it is possible to surely increase the damping force generated when the rebound load is input from the damping force generated when the bound load is input, increase the difference between these two damping forces, and increase the damping force generated when the bound load is input. It is possible to increase the ratio of the damping force generated when the rebound load is input to.

Further, for each of these effects, for example, a member that operates when the hydraulic pressure in the main liquid chamber 15 reaches a predetermined value is not adopted, and the flow resistance of the liquid in the intermediate chamber side portion 21b as described above is not adopted. However, it is higher than the flow resistance of the liquid in the main liquid chamber side portion 21a, and the membrane 31 is played by the configuration which forms a part of the partition wall of both the main liquid chamber 15 and the intermediate chamber 35, so that the amplitude is relatively large. Even if the vibration is small, the above-mentioned action and effect can be stably and accurately performed.
Further, since the cross-sectional area of the intermediate chamber 35 is larger than the flow path cross-sectional area of the intermediate chamber side portion 21b of the first orifice passage 21, when the liquid in the intermediate chamber 35 flows into the intermediate chamber side portion 21b. It is possible to surely increase the generated resistance, and it is possible to surely increase the damping force generated when the rebound load is input.
Further, since the intermediate chamber side portion 21b of the first orifice passage 21 is a passage whose channel length is longer than the channel diameter, the resistance given to the liquid from the auxiliary liquid chamber 16 side flowing through this portion is increased. It can be increased more reliably.

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 first orifice passage 21 extends in the circumferential direction and the second orifice passage 22 extends in the axial direction, but the present invention is not limited to this.
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 15 by the action of a supporting load have been described, but the main liquid chamber 15 is located on the lower side in the vertical direction. In addition, the auxiliary liquid chamber 16 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 15 by applying a supporting load.
Further, the anti-vibration device 1 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 a mount of a generator mounted on a construction machine, or it can be applied to a mount of a machine installed in a factory or the like.

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

1, 2 Anti-vibration device 11 1st mounting member 12 2nd mounting member 13 Elastic body 14 Liquid chamber 15 Main liquid chamber 16 Secondary liquid chamber 17 Partition member 21 1st orifice passage 21a Main liquid chamber side part 21b Intermediate chamber side part 22 2nd Orifice Passage 26, 27 Deterrent Member 31 Membrane 35 Intermediate Chamber

Claims (8)

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 connecting the first mounting member and the second mounting member,
A partition member for partitioning the liquid chamber in the first mounting member into a main liquid chamber and a sub liquid chamber having the elastic body as a part of a partition wall is provided.
The partition member is
Membrane, which forms part of the partition wall of the main liquid chamber,
An intermediate chamber located on the opposite side of the main liquid chamber across the membrane and having the membrane as a part of a partition wall, and an intermediate chamber.
A first orifice passage communicating the main liquid chamber and the intermediate chamber,
A second orifice passage that communicates the intermediate chamber and the auxiliary liquid chamber is provided.
A vibration isolator including a deterrent member that suppresses either one of the bulging deformation toward the intermediate chamber side and the bulging deformation toward the main liquid chamber side of the membrane. The restraining member suppresses the bulging deformation of the membrane toward the intermediate chamber side, and suppresses the bulging deformation of the membrane toward the intermediate chamber side.
The first aspect of the first orifice passage, wherein the liquid flow resistance in the portion located on the main liquid chamber side is higher than the liquid flow resistance in the portion located on the intermediate chamber side. Anti-vibration device. The second aspect of claim 2, wherein the opening direction in which the first orifice passage opens toward the intermediate chamber intersects with the opening direction in which the second orifice passage opens toward the intermediate chamber. Anti-vibration device. A claim characterized in that the cross-sectional area of the intermediate chamber along the direction orthogonal to the opening direction in which the second orifice passage opens toward the intermediate chamber is larger than the flow path cross-sectional area of the second orifice passage. Item 2. The anti-vibration device according to item 2 or 3. The vibration isolator according to any one of claims 2 to 4, wherein the portion of the first orifice passage on the main liquid chamber side is a passage having a flow path length longer than the flow path diameter. The restraining member suppresses the bulging deformation of the membrane toward the main liquid chamber side.
The first aspect of the first orifice passage, wherein the liquid flow resistance in the portion located on the intermediate chamber side is higher than the liquid flow resistance in the portion located on the main liquid chamber side. Anti-vibration device. The cross-sectional area of the intermediate chamber along the direction orthogonal to the opening direction in which the second orifice passage opens toward the intermediate chamber is based on the flow path cross-sectional area of the portion of the first orifice passage on the intermediate chamber side. The anti-vibration device according to claim 6, wherein the vibration isolator is large. The vibration isolator according to claim 6 or 7, wherein the portion of the first orifice passage on the intermediate chamber side is a passage having a flow path length longer than the flow path diameter.

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