JP6978982B2 - 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 cylindrical 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, 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 members are a membrane that forms a part of the partition wall of the main liquid chamber, an intermediate liquid chamber that is located on the opposite side of the membrane and has a membrane as a part of the partition wall, and a main liquid chamber and an intermediate liquid chamber. It is provided with a first orifice passage that communicates with and a second orifice passage that communicates the intermediate liquid 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 the partition wall of the main liquid chamber, and an intermediate liquid chamber that is located on the opposite side of the main liquid chamber and has the membrane as a part of the partition wall. The first orifice passage that communicates the main liquid chamber and the intermediate liquid chamber, the second orifice passage that communicates the intermediate liquid chamber and the sub liquid chamber, and the outer peripheral edge portion of the membrane are the main liquid chamber. The first orifice passage is located on the main liquid chamber side and the intermediate liquid chamber side. The intermediary liquid chamber side passage is provided, and one of the main liquid chamber side passage and the intermediate liquid chamber side passage has a lower liquid flow resistance than the other passage, and the sandwiching member has a lower liquid flow resistance. Of the main liquid chamber and the intermediate liquid chamber, the first sandwiching portion that supports the membrane from the liquid chamber side located on the one passage side in the flow direction of the liquid in the first orifice passage, and the said. A second sandwiching portion that supports the membrane from the other liquid chamber side located on the other passage side in the flow direction of the liquid in the first orifice passage is provided, and the first sandwiching portion is the second. It is characterized in that it protrudes inward in the radial direction longer than the sandwiched portion.

According to the present invention, of the first sandwiching portion and the second sandwiching portion, the first sandwiching portion that protrudes inward in the radial direction supports the membrane from the liquid chamber side of the one, and is the first. 2 Since the sandwiching portion supports the membrane from the other liquid chamber side, the amount of swelling deformation of the membrane when the same pressing force is applied is larger than the bulging deformation toward the other liquid chamber side. The bulging deformation toward the liquid chamber side of one of the above is smaller.
Specifically, in the first orifice passage connecting the main liquid chamber and the intermediate liquid chamber, when the liquid flow resistance in the intermediate liquid chamber side passage is lower than the liquid flow resistance in the main liquid chamber side passage, the first. 2 Since the first sandwiching portion that protrudes inward in the radial direction from the sandwiching portion supports the membrane from the intermediate liquid chamber side, the membrane bulges when the same pressing force is applied. The amount of deformation is smaller for the bulging deformation toward the intermediate liquid chamber side than for the bulging deformation toward the main liquid chamber side.
That is, when the bound load is input to the vibration isolator, the bulging deformation of the membrane toward the intermediate liquid chamber side is suppressed by the first interlocking portion, and the positive pressure of the main liquid chamber is difficult to relax, resulting in damping. While the force increases, when the rebound load is input to the vibration isolator, the second pinching part does not protrude inward in the radial direction from the first pinching part, so it faces the main liquid chamber side of the membrane. The swelling deformation becomes larger than the swelling deformation toward the intermediate liquid chamber side when the bound load is input, and the generated damping force can be suppressed to a low level.
Further, as described above, when the liquid flow resistance in the intermediate liquid chamber side passage is lower than the liquid flow resistance in the main liquid chamber side passage, the liquid in the main liquid chamber is on the main liquid chamber side when the bound load is input. When flowing into the passage, a large resistance is imparted as compared with the case where the liquid flows directly into the intermediate liquid chamber side passage. 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 passage and the intermediate liquid chamber side passage are different from each other, both of them Since one orifice passage is formed continuously 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 to a low level. ..
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, as described above, since the membrane is more likely to bulge and deform toward the main liquid chamber side than the intermediate liquid chamber side, the main liquid chamber suddenly becomes negative pressure with the input of a large rebound load. Even if it tries to do so, the membrane bulges and deforms toward the main liquid chamber, so that the negative pressure in the main liquid chamber can be suppressed and the occurrence of cavitation can also be suppressed.

Contrary to the above, when the liquid flow resistance in the main liquid chamber side passage is lower than the liquid flow resistance in the intermediate liquid chamber side passage, the second pinching portion projects longer inward in the radial direction. 1 Since the sandwiching portion supports the membrane from the main liquid chamber side, the amount of swelling deformation of the membrane when the same pressing force is applied is larger than the swelling deformation toward the intermediate liquid chamber side. The bulging deformation toward the room side is smaller.
That is, when the rebound load is input to the vibration isolator, the bulging deformation toward the main liquid chamber side of the membrane is suppressed by the first interlocking portion, and the negative pressure in the main liquid chamber is difficult to relax, and the generated damping While the force increases, when the bound load is input to the vibration isolator, the second pinching part does not protrude inward in the radial direction from the first pinching part, so it faces the intermediate liquid chamber side of the membrane. The swelling deformation becomes larger than the swelling deformation toward the main liquid chamber side when the rebound load is input, and the generated damping force can be suppressed low.
Further, as described above, when the liquid flow resistance in the main liquid chamber side passage is lower than the liquid flow resistance in the intermediate liquid chamber side passage, the liquid in the secondary liquid chamber is transferred to the second orifice passage when the rebound load is input. When the liquid flows into the intermediate liquid chamber side passage after flowing into the intermediate liquid chamber side passage through the liquid passage, a large resistance is imparted as compared with the case where the liquid flows directly into the main liquid chamber side passage. 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 passage and the intermediate liquid chamber side passage are different from each other, both of them Since one orifice passage is formed continuously 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. ..
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, each of the above-mentioned effects has, for example, the liquid flow resistance in the intermediate liquid chamber side passage as described above, and the liquid flow resistance in the intermediate liquid chamber side passage, as described above, without adopting a member that operates when the liquid pressure in the main liquid chamber reaches a predetermined value. The flow resistance of the liquid in the main liquid chamber side passage is different from each other, and the membrane forms a part of the partition wall of both the main liquid chamber and the intermediate liquid chamber, and the sandwiching member is the first sandwiching portion and the second sandwiching portion. Since it is played by the configuration including the part, even if the vibration has a relatively small amplitude, the above-mentioned action and effect can be stably and accurately performed.

Here, in the inner peripheral edge portion of the first sandwiching portion, the portion with which the membrane abuts may be gradually inclined toward the inside in the radial direction so as to be separated from the other liquid chamber.

In this case, in the inner peripheral edge portion of the first sandwiching portion, the portion with which the membrane abuts is gradually inclined toward the inside in the radial direction so as to be away from the other liquid chamber. When the membrane bulges and deforms toward one of the liquid chambers, it becomes easy to make surface contact with the inner peripheral edge of the first sandwiching portion, which can suppress the generation of abnormal noise and the durability of the membrane. Sex can be ensured.

Further, the membrane may abut on the inner peripheral edge portion of the first sandwiching portion.
In this case, since the membrane is in contact with the inner peripheral edge of the first sandwiching portion, it is possible to prevent the membrane from colliding with the inner peripheral edge of the first sandwiching portion when vibration is input. , The generation of abnormal noise can be reliably suppressed. Further, since the membrane is in contact with the inner peripheral edge of the first sandwiching portion, a load that causes the membrane to bulge and deform toward one of the liquid chambers is applied even if the vibration has a relatively small amplitude. When input, a high damping force can be generated.

Further, the membrane includes an outer peripheral edge portion sandwiched between the sandwiching members, and a main body portion located radially inside the outer peripheral edge portion and formed thickly, and the main body portion of the main body portion. Of these, a radial gap may be provided between the outer peripheral surface of the portion located on the other liquid chamber side from the outer peripheral edge portion and the inner peripheral surface of the second sandwiching portion.

In this case, since a radial gap is provided between the outer peripheral surface of the main body of the membrane and the inner peripheral surface of the second sandwiching portion, the membrane can be squeezed even if the vibration has a relatively small amplitude. , The other liquid chamber side can be smoothly bulged and deformed, and the generated damping force can be surely suppressed to a low level. Further, when the membrane tries to bulge and deform excessively toward the other liquid chamber side, the outer peripheral surface of the main body portion can be brought into contact with the inner peripheral surface of the second sandwiching portion. , It is possible to prevent a large load from being applied to the connection portion between the outer peripheral edge portion and the main body portion in the membrane.

Further, when the same pressing force is applied to the membrane, the swelling deformation toward the other liquid chamber side is larger than the swelling deformation toward the one liquid chamber side. The portions may be formed.

In this case, since the uneven bulging portion is formed on the membrane, the same pressing force is applied in combination with the fact that the sandwiching member has the first sandwiching portion and the second sandwiching portion. It is possible to surely make the bulging deformation of the membrane toward the one liquid chamber side smaller than the bulging deformation of the membrane toward the other liquid chamber side at the time of the bound load. The damping force generated at the time of input and the damping force generated at the time of inputting the rebound load can be greatly different.
Specifically, when the liquid flow resistance in the intermediate liquid chamber side passage is lower than the liquid flow resistance in the main liquid chamber side passage, the amount of swelling deformation of the membrane when the same pressing force is applied is intermediate. The swelling deformation toward the main liquid chamber side is larger than the swelling deformation toward the liquid chamber side.
Therefore, when the rebound load is input to the vibration isolator, the membrane is greatly bulged and deformed toward the main liquid chamber side by the uneven bulging portion, so that the generated damping force can be suppressed to a low level. On the other hand, when the bound load is input to the vibration isolator, the bulging deformation toward the intermediate liquid chamber side of the membrane becomes smaller than the bulging deformation toward the main liquid chamber side when the rebound load is input. The positive pressure in the main liquid chamber is difficult to relax, and the generated damping force increases.
Contrary to the above, when the liquid flow resistance in the main liquid chamber side passage is lower than the liquid flow resistance in the intermediate liquid chamber side passage, the amount of swelling deformation of the membrane when the same pressing force is applied is The amount of swelling deformation toward the intermediate liquid chamber side is larger than the amount of swelling deformation toward the main liquid chamber side.
Therefore, when the bound load is input to the vibration isolator, the membrane is greatly bulged and deformed toward the intermediate liquid chamber side by the uneven bulging portion, so that the generated damping force can be suppressed to a low level. On the other hand, when the rebound load is input to the vibration isolator, the swelling deformation toward the main liquid chamber side of the membrane becomes smaller than the swelling deformation toward the intermediate liquid chamber side when the bound load is input. The negative pressure in the main liquid chamber is difficult to relieve, and the generated damping force increases.

Further, the uneven bulging portion may be formed in a curved surface shape with a protrusion toward one of the liquid chambers.

In this case, when the same pressing force is applied to the membrane, it is easy to configure the configuration in which the swelling deformation toward the other liquid chamber side becomes larger than the swelling deformation toward the other liquid chamber side. It can be surely realized.

Further, the unevenly bulging portion may project inside the first sandwiching portion.

In this case, since the uneven bulging portion protrudes inside the first sandwiching portion, the bulging deformation of the membrane toward the other liquid chamber side when the same pressing force is applied is described above. It is possible to more reliably realize a configuration that is larger than the bulging deformation of the membrane toward one liquid chamber side.

Further, a plurality of support protrusions may be formed on at least one of the first sandwiching portion and the outer peripheral edge portion of the membrane so as to project and abut against the other.

In this case, since a plurality of support protrusions are formed on at least one of the first sandwiching portion and the outer peripheral edge portion of the membrane so as to project and abut toward the other, a load is input to the vibration isolator. When the membrane is deformed or displaced toward one of the liquid chambers, it becomes possible to suppress the outer peripheral edge portion of the membrane from colliding with the first sandwiching portion at once over a wide range, and the hitting generated occurs. The sound can be suppressed to a low level.

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. It is a vertical sectional view of the vibration isolation device which concerns on 3rd Embodiment of this invention. It is a schematic diagram of the vibration isolation device shown in FIG. It is a vertical sectional view of the vibration isolation device which concerns on 4th Embodiment of this invention. It is a schematic diagram of the vibration isolation device shown in FIG. 7. It is a vertical sectional view of the vibration isolation device which concerns on 5th Embodiment of this invention. It is a vertical sectional view which shows the modification of the vibration isolation device which concerns on 5th Embodiment of this invention.

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 cylindrical first mounting member 11 connected to either 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, a first mounting member 11 is connected to a vehicle body as a vibration receiving portion, and a second mounting member 12 is connected to an engine as a vibration generating portion. .. As a result, the vibration of the engine is suppressed from being transmitted to the vehicle body. The first mounting member 11 may be connected to the vibration generating portion, and the second mounting member 12 may be connected to the vibration receiving portion.

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 that intersects the central axis O is referred to as the radial direction, and the direction that orbits around the central axis O is referred to as the circumferential direction.

The first mounting member 11 is formed in the shape of a bottomed cylinder. 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 elastic body 13 seals the upper end opening of the first mounting member 11. 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 climax cylinder 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 in the lower end portion of the first mounting member 11 via the coated rubber. The diaphragm ring 18 is formed in a double cylindrical 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 bonded to the diaphragm ring 18. Of the diaphragm ring 18, the outer peripheral portion of the diaphragm 19 is vulcanized and bonded to the inner peripheral surface of the outer cylinder portion and the outer peripheral surface of the inner cylinder portion. 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 enclosed 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 in the first mounting member 11 via the coated 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. An intermediate liquid chamber 35 located on the opposite side of the main liquid chamber 15 with the membrane 31 sandwiched between the membrane 31 forming the main body member 34 and the lower member 33 closing the lower end opening of the main body member 34 and having the membrane 31 as a part of the partition wall. An annular sandwiching member 39 for fixing the membrane 31 to the main body member 34, a first orifice passage 21 for communicating the main liquid chamber 15 and the intermediate liquid chamber 35, and the intermediate liquid chamber 35 and the auxiliary liquid chamber 16. A second orifice passage 22 for communication is provided.

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 membrane 31 is formed to be thinner than the disk-shaped main body portion 31b and the main body portion 31b, and protrudes outward in the radial direction from the lower portion of the main body portion 31b, and the outer peripheral edge portion 31a continuously extends over the entire circumference. And. The upper and lower surfaces of the main body 31b extend in a direction orthogonal to the axial direction over the entire area. At the outer end portion in the radial direction of the outer peripheral edge portion 31a, locking protrusions protruding toward both sides in the axial direction are formed.

The main body member 34 is arranged coaxially with the central axis O. 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 member 34. The radial outer opening in 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 member 34. 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 sandwiching member 39 sandwiches the outer peripheral edge portion 31a of the membrane 31 from both sides of the main liquid chamber 15 side and the intermediate liquid chamber 35 side. The sandwiching member 39 includes a first sandwiching portion 25 that supports the lower surface of the membrane 31 and a second sandwiching portion 38 that supports the upper surface of the membrane 31. The first sandwiching portion 25 and the second sandwiching portion 38 are each formed in an annular shape and are arranged coaxially with the central axis O.
The outer peripheral edge portion 31a of the membrane 31 is sandwiched and fixed in the axial direction by the first sandwiching portion 25 and the second sandwiching portion 38, so that the membrane 31 is axially sandwiched with the outer peripheral edge portion 31a as a fixed end. It is supported so that it can be elastically deformed.

The first sandwiching portion 25 is connected to the main body member 34 via the outer flange portion 24. The outer flange portion 24 is integrally formed with the main body member 34, and protrudes inward in the radial direction from the upper end portion of the main body member 34. The outer flange portion 24 is arranged coaxially with the central axis O. The first sandwiching portion 25 is integrally formed with the outer flange portion 24, and protrudes inward in the radial direction from the outer flange portion 24. The lower surfaces of the first sandwiching portion 25 and the outer flange portion 24 are flush with each other. The upper surface of the first sandwiching portion 25 is located below the upper surface of the outer flange portion 24. A lower annular groove that extends continuously over the entire circumference is formed on the outer peripheral edge portion on the upper surface of the first sandwiching portion 25.

Of the second sandwiching portion 38, the outer peripheral portion 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. An upper annular groove that extends continuously over the entire circumference is formed on the outer peripheral edge portion on the lower surface of the inner peripheral portion of the second sandwiching portion 38. The upper annular groove is axially opposed to the lower annular groove of the first sandwiching portion 25. The locking projections of the outer peripheral edge portion 31a of the membrane 31 are separately locked in the upper annular groove and the lower annular groove.

Here, of the main body portion 31b of the membrane 31, a portion located above the outer peripheral edge portion 31a is inserted inside the inner peripheral portion of the second sandwiching portion 38. Of the main body portion 31b of the membrane 31, the outer peripheral surface of the portion located above the outer peripheral edge portion 31a (hereinafter referred to as the outer peripheral surface 31c of the main body portion 31b of the membrane 31) and the inner peripheral portion of the second sandwiching portion 38. A radial gap is provided between the inner peripheral surface and the inner peripheral surface. The inner peripheral surface of the inner peripheral portion of the second sandwiching portion 38 and the outer peripheral surface 31c of the main body portion 31b of the membrane 31 extend in the axial direction, respectively. The inner peripheral surface of the inner peripheral portion of the second sandwiching portion 38 and the outer peripheral surface 31c of the main body portion 31b of the membrane 31 are substantially parallel to each other. The inner peripheral surface of the inner peripheral portion of the second sandwiching portion 38 and the outer peripheral surface 31c of the main body portion 31b of the membrane 31 may be inclined to each other.

The lower member 33 is formed in a bottomed cylindrical shape and is arranged coaxially with the central axis O. The lower member 33 is liquid-tightly fitted in 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 liquid 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 first sandwiching portion 25 and the outer flange portion 24. 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 liquid 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 liquid chamber 35 and the main liquid chamber 15 are axially partitioned by the membrane 31. The internal volume of the intermediate liquid 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 in the second orifice groove 33a is closed by the inner peripheral surface of the main body member 34. A second communication hole 33b that communicates the second orifice groove 33a and the intermediate liquid 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 and the intermediate liquid chamber 35 in the radial direction.
The second orifice groove 33a extends in the circumferential direction from the second communication hole 33b toward one side in the circumferential direction over an angle range exceeding 180 ° with the central axis O as the center. One end in the circumferential direction in 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 liquid 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 liquid chamber 35 in the axial direction. The opening on the intermediate liquid chamber 35 side in 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. At least a portion of these second orifice passages 22 is axially opposed to the membrane 31.

On the upper surface of the bottom wall portion of the lower member 33, a regulating protrusion 26 for restricting excessively large bulging deformation of the membrane 31 toward the intermediate liquid chamber 35 side is disposed. The regulation protrusion 26 is integrally formed with the lower member 33. The regulation protrusion 26 is formed in a cylindrical shape and is arranged coaxially with the central axis O.
The regulation protrusion 26 may be formed solidly, and may not be arranged coaxially with the central axis O.

On the lower surface of the bottom wall portion of the lower member 33, the diaphragm ring 18 described above 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 radially outside the inner cylinder portion is located radially outside the lower member 33, and the main body member is located on the upper surface of the connecting portion between the outer cylinder portion and the inner cylinder portion. The lower surface of 34 is in close contact with the liquid.

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 larger 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 member 34. 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 liquid chamber 35 has a first orifice groove 23a whose radial outer opening is closed by the covering rubber and a radial outer opening. It is composed of a second orifice groove 33a closed by the inner peripheral surface of the main body member 34 and a connection hole 21c.
Hereinafter, the portion of the first orifice passage 21 located on the main liquid chamber 15 side and defined by the first orifice groove 23a is referred to as a main liquid chamber side passage 21a, and is located on the intermediate liquid chamber 35 side. 2 The portion defined by the orifice groove 33a is referred to as an intermediate liquid chamber side passage 21b.

Here, the connection hole 21c connects the one end in the circumferential direction in the first orifice groove 23a and the one end in the circumferential direction in the second orifice groove 33a. As a result, the liquid flows from either the main liquid chamber side passage 21a or the intermediate liquid chamber side passage 21b into the other through the connection hole 21c, and flows through the other. The flow direction of the liquid 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 liquid flow resistance in the intermediate liquid chamber side passage 21b is lower than the liquid flow resistance in the main liquid chamber side passage 21a.
In the illustrated example, the flow path cross-sectional area of the main liquid chamber side passage 21a is smaller than the flow path cross-sectional area of the intermediate liquid chamber side passage 21b. The opening area of the connection hole 21c is smaller than the flow path cross-sectional area of the main liquid chamber side passage 21a. The flow path length of the connection hole 21c is shorter than the flow path lengths of the main liquid chamber side passage 21a and the intermediate liquid chamber side passage 21b.

Here, the flow resistances of the main liquid chamber side passage 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 passage 21a is higher than the flow resistance of the first communication hole 23b, the flow resistance of the liquid when passing through the first communication hole 23b and entering the main liquid chamber side passage 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 auxiliary liquid chamber 16 side.

Further, the flow resistances of the connection hole 21c and the main liquid chamber side passage 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 passage 21a, the flow resistance of the liquid when passing through the main liquid chamber side passage 21a and entering 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 liquid chamber side passage 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 liquid chamber side passage 21b is higher than the flow resistance of the connection hole 21c, the flow resistance of the liquid when passing through the connection hole 21c and entering the intermediate liquid chamber side passage 21b increases and bounces. A high damping force is generated when the load is input.

Further, the flow resistances of the second communication hole 33b and the intermediate liquid chamber side passage 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 liquid chamber side passage 21b, the flow resistance of the liquid when passing through the intermediate liquid chamber side passage 21b and entering the second communication hole 33b is high. It increases and 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 liquid chamber 35, that is, the opening direction in the intermediate liquid chamber 35 of the second communication hole 33b, is the intermediate liquid in the second orifice passage 22. It intersects the opening direction that opens toward the chamber 35. In the illustrated example, the second communication hole 33b opens radially toward the intermediate liquid chamber 35, and the second orifice passage 22 opens axially toward the intermediate liquid chamber 35. That is, the opening direction of the second communication hole 33b toward the intermediate liquid chamber 35 is orthogonal to the opening direction of the second orifice passage 22 toward the intermediate liquid chamber 35.

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

Here, in the present embodiment, the intermediate liquid chamber 35 is an intermediate liquid chamber having a low liquid flow resistance among the main liquid chamber side passage 21a and the intermediate liquid chamber side passage 21b in the liquid flow direction in the first orifice passage 21. It is located on the side passage 21b side.
Then, in the present embodiment, the first sandwiching portion 25 that supports the membrane 31 from the intermediate liquid chamber 35 side is radially inside the second sandwiching portion 38 that supports the membrane 31 from the main liquid chamber 15 side. It protrudes long. In the first sandwiching portion 25, the portion located inside the second sandwiching portion 38 in the radial direction supports the outer peripheral portion on the lower surface of the main body portion 31b of the membrane 31. At the inner peripheral edge of the first sandwiching portion 25, the upper surface to which the membrane 31 abuts is gradually inclined downward toward the inside in the radial direction and away from the main liquid chamber 15. In the illustrated example, the upper surface of the inner peripheral edge portion of the first sandwiching portion 25 is formed in a curved surface shape with a protrusion toward the main liquid chamber 15 side. The membrane 31 is in contact with the entire lower surface of the second sandwiching portion 38.
The upper surface of the inner peripheral edge portion of the first sandwiching portion 25 may be a flat surface extending in a direction orthogonal to the central axis O. The membrane 31 may abut over the entire upper surface of the first sandwiching portion 25.

As described above, according to the vibration isolator 1 according to the present embodiment, the first sandwiching portion 25 protruding inward in the radial direction from the second sandwiching portion 38 makes the membrane 31 an intermediate liquid. Since it is supported from the chamber 35 side, the amount of swelling deformation of the membrane 31 when the same pressing force is applied is swelling toward the intermediate liquid chamber 35 side rather than the swelling deformation toward the main liquid chamber 15 side. The output deformation is smaller.
That is, when the bound load is input to the vibration isolator 1, the bulging deformation of the membrane 31 toward the intermediate liquid chamber 35 side is suppressed by the first sandwiching portion 25, and the positive pressure of the main liquid chamber 15 is relaxed. It is difficult and the generated damping force becomes high, but when the rebound load is input to the vibration isolator 1, the second sandwiching portion 38 does not protrude inward in the radial direction from the first sandwiching portion 25, so that the membrane is The bulging deformation toward the main liquid chamber 15 side of 31 is larger than the bulging deformation toward the intermediate liquid chamber 35 side when the bound load is input, and the generated damping force can be suppressed low.

Further, since the flow resistance of the liquid in the intermediate liquid chamber side passage 21b is lower than the flow resistance of the liquid in the main liquid chamber side passage 21a, the liquid in the main liquid chamber 15 is transferred to the main liquid chamber side passage 21a when the bound load is input. When flowing into the intermediate liquid chamber side passage 21b, a large resistance is imparted as compared with the case where the liquid flows directly into the intermediate liquid chamber side passage 21b. 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, the flow resistance differs between the main liquid chamber side passage 21a and the intermediate liquid chamber side passage 21b. Even so, 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, and the damping force generated when the rebound load is input can be suppressed. It can be kept low.
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, as described above, since the membrane 31 is more likely to bulge and deform toward the main liquid chamber 15 side than the intermediate liquid chamber 35 side, the main liquid chamber 15 suddenly expands with the input of a large rebound load. Even if it tries to become a negative pressure, the membrane 31 bulges and deforms toward the main liquid chamber 15, so that the negative pressure of the main liquid chamber 15 can be suppressed and the occurrence of cavitation can be suppressed. can.
Further, each of the above-mentioned effects does not employ, for example, a member that operates when the liquid pressure in the main liquid chamber 15 reaches a predetermined value, and the liquid flows in the intermediate liquid chamber side passage 21b as described above. The resistance and the flow resistance of the liquid in the main liquid chamber side passage 21a are different from each other, the membrane 31 forms a part of the partition wall of both the main liquid chamber 15 and the intermediate liquid chamber 35, and the sandwiching member 39 is the first. Since it is played by the configuration including the sandwiching portion 25 and the second sandwiching portion 38, the above-mentioned action and effect can be stably and accurately performed even with a vibration having a relatively small amplitude.

Further, in the inner peripheral edge portion of the first sandwiching portion 25, the upper surface with which the membrane 31 abuts is gradually inclined toward the inside in the radial direction so as to be gradually separated from the main liquid chamber 15, so that when a bound load is input. When the membrane 31 bulges and deforms toward the intermediate liquid chamber 35 side, it becomes easy to make surface contact with the inner peripheral edge portion of the first sandwiching portion 25, and it is possible to suppress the generation of abnormal noise and the membrane. The durability of 31 can be ensured.

Further, since a radial gap is provided between the outer peripheral surface 31c of the main body portion 31b of the membrane 31 and the inner peripheral surface of the inner peripheral portion of the second sandwiching portion 38, vibration having a relatively small amplitude is provided. Even so, when the rebound load is input, the membrane 31 can be smoothly bulged and deformed toward the main liquid chamber 15, and the generated damping force can be reliably suppressed to a low level. Further, when the membrane 31 tries to bulge and deform excessively toward the main liquid chamber 15 side when the rebound load is input, the outer peripheral surface 31c of the main body portion 31b is changed to the inner peripheral portion of the second sandwiching portion 38. It is also possible to bring it into contact with the inner peripheral surface of the member, and it is possible to prevent a large load from being applied to the connection portion between the outer peripheral edge portion 31a and the main body portion 31b in the membrane 31.
Further, since the main liquid chamber side passage 21a of the first orifice passage 21 is a passage whose flow path length is longer than the flow path diameter, the resistance applied to the liquid from the main liquid chamber 15 side flowing through this portion is increased. It is increased, and the damping force generated when the bound load is input can be increased more reliably.

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

Further, since the cross-sectional area of the intermediate liquid chamber 35 is larger than the flow path cross-sectional area of the second orifice passage 22, the resistance generated when the liquid of the intermediate liquid chamber 35 flows into the second orifice passage 22 is increased. This makes it possible to reliably increase the damping force generated when a bound load is input.

Next, the vibration isolator 2 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.

In the present embodiment, when the same pressing force is applied to the membrane 31, the swelling deformation toward the main liquid chamber 15 side is larger than the swelling deformation toward the intermediate liquid chamber 35 side. The portion 23 is formed. The uneven bulging portion 23 is curved so as to protrude toward the intermediate liquid chamber 35 side. The uneven bulging portion 23 is integrally formed over the entire area of the main body portion 31b of the membrane 31 located inside the outer peripheral edge portion 31a axially sandwiched by the sandwiching member 39 in the radial direction. The uneven bulging portion 23 is not limited to the above-mentioned curved shape, and may be appropriately changed, for example, by changing the size of the grooves formed on the upper and lower surfaces of the membrane 31.

The lower surface of the membrane 31 is in contact with the upper surface of the inner peripheral edge portion of the first sandwiching portion 25. The unevenly bulging portion 23 of the membrane 31 projects inside the first sandwiching portion 25. The positions of the lower end portion on the lower surface of the unevenly bulging portion 23 and the lower surface of the first sandwiching portion 25 in the axial direction are equal to each other. The lower surface of the membrane 31 is not in contact with the inner peripheral surface of the first sandwiching portion 25. The membrane 31 is in contact with the entire surface of the upper surface of the first sandwiching portion 25 and the lower surface of the inner peripheral portion of the second sandwiching portion 38.
The lower surface of the membrane 31 may be separated upward from the upper surface of the inner peripheral edge portion of the first sandwiching portion 25. The uneven bulging portion 23 of the membrane 31 may be positioned above the inner peripheral surface of the first sandwiching portion 25. The lower surface of the membrane 31 may be brought into contact with the inner peripheral surface of the first sandwiching portion 25.

As described above, according to the vibration isolator 2 according to the present embodiment, since the uneven bulging portion 23 is formed on the membrane 31, the bulging deformation of the membrane 31 when the same pressing force is applied. The amount is larger in the bulging deformation toward the main liquid chamber 15 side than in the bulging deformation toward the intermediate liquid chamber 35 side.
Therefore, when the rebound load is input to the vibration isolator 1, the membrane 31 is greatly bulged and deformed toward the main liquid chamber 15 by the eccentric bulging portion 23, so that the generated damping force can be suppressed to a low level. can. On the other hand, when the bound load is input to the vibration isolator 1, the bulging deformation toward the intermediate liquid chamber 35 side of the membrane 31 is compared with the bulging deformation toward the main liquid chamber 15 side when the rebound load is input. The positive pressure in the main liquid chamber 15 is difficult to relax, and the generated damping force increases.
From the above, the ratio of the damping force generated when the bound load is input to the damping force generated when the rebound load is input can be surely increased.

Further, since the uneven bulging portion 23 is curved so as to protrude toward the intermediate liquid chamber 35 side, when the same pressing force is applied to the membrane 31, the uneven bulging portion 23 is directed toward the intermediate liquid chamber 35 side. It is possible to easily and surely realize a configuration in which the swelling deformation toward the main liquid chamber 15 side is larger than the swelling deformation.
Further, since the uneven bulging portion 23 overhangs the inside of the first sandwiching portion 25, the bulging deformation of the membrane 31 toward the main liquid chamber 15 side when the same pressing force is applied can be obtained. It is possible to more reliably realize a configuration that is larger than the bulging deformation of the membrane 31 toward the intermediate liquid chamber 35 side.

Further, since the uneven bulging portion 23 is integrally formed over the entire area of the main body portion 31b located inside the outer peripheral edge portion 31a axially sandwiched by the sandwiching member 39 in the membrane 31 among the membranes 31. , The membrane 31 can be greatly bulged and deformed toward the main liquid chamber 15, and the damping force generated when the bound load is input and the damping force generated when the rebound load is input can be greatly different. ..
Further, since the membrane 31 is in contact with the inner peripheral edge portion of the first sandwiching portion 25, it is possible to prevent the membrane 31 from colliding with the inner peripheral edge portion of the first sandwiching portion 25 when a bound load is input. Is possible, and the generation of abnormal noise can be reliably suppressed. Further, since the membrane 31 is in contact with the inner peripheral edge portion of the first sandwiching portion 25, a high damping force can be generated when a bound load is input even if the vibration has a relatively small amplitude.

Next, the vibration isolator 3 according to the third embodiment of the present invention will be described with reference to FIGS. 5 and 6.
In the third 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 projects radially outward from the lower end of the lower member 33, and the lower surface of the main body member 34 is in liquidtight contact with the upper surface thereof. The diaphragm ring 28 is integrally formed with the lower member 33.
The outer flange portion 24 projects upward from the inner peripheral edge portion on the upper surface of the main body member 34. The inner peripheral surfaces of the outer flange portion 24 and the main body member 34 are flush with each other.

Further, in the present embodiment, the liquid flow resistance in the main liquid chamber side passage 21a is lower than the liquid flow resistance in the intermediate liquid chamber side passage 21b. In the illustrated example, the flow path cross-sectional area of the intermediate liquid chamber side passage 21b is smaller than the flow path cross-sectional area of the main liquid chamber side passage 21a. Further, the opening area of the connection hole 21c is smaller than the flow path cross-sectional area of the intermediate liquid chamber side passage 21b.

Here, the flow resistances of the intermediate liquid chamber side passage 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 liquid chamber side passage 21b is higher than the flow resistance of the second communication hole 33b, the flow resistance of the liquid when passing through the second communication hole 33b and entering the intermediate liquid chamber side passage 21b is high. A high damping force is generated at the time of input of the rebound load which increases and circulates the liquid from the auxiliary liquid chamber 16 toward the main liquid chamber 15 side.

Further, the flow resistances of the connection hole 21c and the intermediate liquid chamber side passage 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 liquid chamber side passage 21b, the flow resistance of the liquid when passing through the intermediate liquid chamber side passage 21b and entering the connection hole 21c increases and rebounds. A high damping force is generated when the load is input.

Further, the flow resistances of the main liquid chamber side passage 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 passage 21a is higher than the flow resistance of the connection hole 21c, the flow resistance of the liquid when passing through the connection hole 21c and entering the main liquid chamber side passage 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 passage 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 passage 21a, the flow resistance of the liquid when it passes through the main liquid chamber side passage 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.

Here, in the present embodiment, the main liquid chamber 15 has a main liquid chamber having a low liquid flow resistance among the main liquid chamber side passage 21a and the intermediate liquid chamber side passage 21b in the liquid flow direction in the first orifice passage 21. It is located on the side passage 21a side.
Then, in the present embodiment, the first sandwiching portion 27 protruding inward in the radial direction from the second sandwiching portion 29 supports the membrane 37 from the main liquid chamber 15 side, and the second sandwiching portion 29 supports the membrane 37 from the intermediate liquid chamber 35 side.

The second sandwiching portion 29 is integrally formed with the outer flange portion 24, and protrudes inward in the radial direction from the outer flange portion 24. The upper end opening edge of the peripheral wall portion of the lower member 33 is in contact with the lower surface of the second sandwiching portion 29. The upper surface of the second sandwiching portion 29 is located below the upper surface of the outer flange portion 24. A lower annular groove that continuously extends over the entire circumference is formed on the outer peripheral edge portion on the upper surface of the second sandwiching portion 29.

Here, the membrane 37 is formed to be thinner than the disk-shaped main body portion 37b and the main body portion 37b, and protrudes outward in the radial direction from the upper portion of the main body portion 37b, and extends continuously over the entire circumference. A peripheral portion 37a is provided.
The portion of the main body portion 37b of the membrane 37 located below the outer peripheral edge portion 37a is inserted inside the second sandwiching portion 29. Of the main body 37b of the membrane 37, the outer peripheral surface of the portion located below the outer peripheral edge 37a (hereinafter referred to as the outer peripheral surface 37c of the main body 37b of the membrane 37) and the inner peripheral surface of the second sandwiching portion 29. A radial gap is provided between the ,. The inner peripheral surface of the second sandwiching portion 29 and the outer peripheral surface 37c of the main body portion 37b of the membrane 37 extend in the axial direction, respectively. The inner peripheral surface of the second sandwiching portion 29 and the outer peripheral surface 37c of the main body portion 37b of the membrane 37 are substantially parallel to each other. The inner peripheral surface of the second sandwiching portion 38 and the outer peripheral surface 37c of the main body portion 37b of the membrane 37 may be inclined to each other.

Of the first sandwiching portion 27, the outer peripheral portion is arranged on the upper surface of the outer flange portion 24, and the inner peripheral portion supports the upper surface of the membrane 37. An upper annular groove that extends continuously over the entire circumference is formed on the outer peripheral edge portion on the lower surface of the inner peripheral portion of the first sandwiching portion 27. The upper annular groove is axially opposed to the lower annular groove of the second sandwiching portion 29. The locking projections of the outer peripheral edge portion 37a of the membrane 37 are separately locked in the upper annular groove and the lower annular groove.

In the first sandwiching portion 27, the portion located radially inside the second sandwiching portion 29 supports the outer peripheral portion on the upper surface of the main body portion 37b of the membrane 37. In the inner peripheral edge portion of the inner peripheral portion of the first sandwiching portion 27 (hereinafter referred to as the inner peripheral edge portion of the first sandwiching portion 27), the lower surface with which the membrane 37 abuts gradually becomes an intermediate liquid as it goes inward in the radial direction. It is inclined upward so as to be away from the room 35. In the illustrated example, the lower surface of the inner peripheral edge portion of the first sandwiching portion 27 is formed in a curved surface shape with a protrusion toward the intermediate liquid chamber 35 side. The membrane 37 is in contact with the entire upper surface of the second sandwiching portion 29.
The lower surface of the inner peripheral edge portion of the first sandwiching portion 27 may be a flat surface extending in a direction orthogonal to the central axis O. The membrane 37 may abut over the entire lower surface of the first sandwiching portion 27.

As described above, according to the vibration isolator 3 according to the present embodiment, the first sandwiching portion 27 protruding inward in the radial direction from the second sandwiching portion 29 makes the membrane 37 the main liquid. Since it is supported from the chamber 15 side, the amount of swelling deformation of the membrane 37 when the same pressing force is applied is swelling toward the main liquid chamber 15 side from the swelling deformation toward the intermediate liquid chamber 35 side. The output deformation is smaller.
That is, when the rebound load is input to the vibration isolator 2, the bulging deformation of the membrane 37 toward the main liquid chamber 15 side is suppressed by the first sandwiching portion 27, and the negative pressure of the main liquid chamber 15 is relaxed. It is difficult and the generated damping force is high, but when the bound load is input to the vibration isolator 2, the second sandwiching portion 29 does not protrude inward in the radial direction from the first sandwiching portion 27, so that the membrane is The bulging deformation toward the intermediate liquid chamber 35 side of 37 is larger than the bulging deformation toward the main liquid chamber 15 side when the rebound load is input, and the generated damping force can be suppressed low.

Further, since the liquid flow resistance in the main liquid chamber side passage 21a is lower than the liquid flow resistance in the intermediate liquid chamber side passage 21b, the liquid in the auxiliary liquid chamber 16 passes through the second orifice passage 22 when the rebound load is input. When the liquid flows into the intermediate liquid chamber 35 and then flows into the intermediate liquid chamber side passage 21b, a large resistance is imparted as compared with the case where the liquid flows directly into the main liquid chamber side passage 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, the flow resistances of the main liquid chamber side passage 21a and the intermediate liquid chamber side passage 21b are different from each other. Even so, 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, and the damping force generated when the bound load is input can be suppressed. It can be suppressed.
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, at the inner peripheral edge portion of the first sandwiching portion 27, the lower surface with which the membrane 37 abuts is gradually inclined toward the inside in the radial direction so as to be gradually separated from the intermediate liquid chamber 35, so that when a rebound load is input. When the membrane 37 bulges and deforms toward the main liquid chamber 15, it becomes easy to make surface contact with the inner peripheral edge portion of the first sandwiching portion 27, and it is possible to suppress the generation of abnormal noise and the membrane. The durability of 37 can be ensured.

Further, since a radial gap is provided between the outer peripheral surface 37c of the main body portion 37b of the membrane 37 and the inner peripheral surface of the second sandwiching portion 29, even if the vibration has a relatively small amplitude. When the bound load is input, the membrane 37 can be smoothly bulged and deformed toward the intermediate liquid chamber 35 side, and the generated damping force can be surely suppressed to a low level. Further, when the membrane 37 tries to bulge and deform excessively toward the intermediate liquid chamber 35 side when the bound load is input, the outer peripheral surface 37c of the main body portion 37b is changed to the inner peripheral surface of the second sandwiching portion 29. It is also possible to bring the member into contact with the surface, and it is possible to prevent a large load from being applied to the connection portion between the outer peripheral edge portion 37a and the main body portion 37b in the membrane 37.

Further, since the cross-sectional area of the intermediate liquid chamber 35 is larger than the flow path cross-sectional area of the intermediate liquid chamber side passage 21b of the first orifice passage 21, the liquid in the intermediate liquid chamber 35 becomes the intermediate liquid chamber side passage 21b. It is possible to surely increase the resistance generated when the inflow occurs, and it is possible to surely increase the damping force generated when the rebound load is input.
Further, since the intermediate liquid chamber side passage 21b of the first orifice passage 21 is a passage whose flow path length is longer than the flow path diameter, the resistance applied to the liquid from the auxiliary liquid chamber 16 side flowing through this portion is increased. It is increased, and the damping force generated when the rebound load is input can be increased more reliably.

Next, the vibration isolator 4 according to the fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8.
In the fourth embodiment, the same parts as the components in the third embodiment are designated by the same reference numerals, the description thereof will be omitted, and only the different points will be described.

In the present embodiment, when the same pressing force is applied to the membrane 37, the uneven bulging portion 36 is bulging deformed toward the intermediate liquid chamber 35 side rather than the bulging deformation toward the main liquid chamber 15 side. Is formed to increase the size. In the illustrated example, the swelling portion 36 is curved so as to protrude toward the main liquid chamber 15 side.

The upper surface of the membrane 37 is in contact with the lower surface of the inner peripheral edge portion of the inner peripheral portion of the first sandwiching portion 27 (hereinafter referred to as the inner peripheral edge portion of the first sandwiching portion 27). The unevenly bulging portion 36 of the membrane 37 projects inside the first sandwiching portion 27. The positions of the upper end portion of the upper surface of the unevenly bulging portion 36 and the upper surface of the first sandwiching portion 27 in the axial direction are equal to each other. The upper surface of the membrane 37 is not in contact with the inner peripheral surface of the inner peripheral portion of the first sandwiching portion 27. The membrane 37 is in contact with the lower surface of the inner peripheral portion of the first sandwiching portion 27 and the upper surface of the second sandwiching portion 29 over the entire area.
The upper surface of the membrane 37 may be separated downward from the lower surface of the inner peripheral edge portion of the first sandwiching portion 27. The unevenly bulging portion 36 of the membrane 37 may be positioned below the inner peripheral surface of the inner peripheral portion of the first sandwiching portion 27. The upper surface of the membrane 37 may be brought into contact with the inner peripheral surface of the inner peripheral portion of the first sandwiching portion 27.

As described above, according to the vibration isolator 4 according to the present embodiment, since the uneven bulging portion 36 is formed on the membrane 37, the bulging deformation of the membrane 37 when the same pressing force is applied. The amount is larger in the bulging deformation toward the intermediate liquid chamber 35 side than in the bulging deformation toward the main liquid chamber 15 side.
Therefore, when the bound load is input to the vibration isolator 2, the membrane 37 is greatly bulged and deformed toward the intermediate liquid chamber 35 by the eccentric bulging portion 36, so that the generated damping force can be suppressed to a low level. can. On the other hand, when the rebound load is input to the vibration isolator 2, the swelling deformation toward the main liquid chamber 15 side of the membrane 37 is compared with the swelling deformation toward the intermediate liquid chamber 35 side when the bound load is input. The negative pressure in the main liquid chamber 15 is difficult to relax, and the generated damping force increases.
From the above, the ratio of the damping force generated when the rebound load is input to the damping force generated when the bound load is input can be surely increased.

Further, since the uneven bulging portion 36 is curved so as to be a protrusion toward the main liquid chamber 15, it is directed toward the main liquid chamber 15 side when the same pressing force is applied to the membrane 37. It is possible to easily and surely realize a configuration in which the swelling deformation toward the intermediate liquid chamber 35 side is larger than the swelling deformation.
Further, since the uneven bulging portion 36 projects inside the first sandwiching portion 27, the bulging deformation of the membrane 37 toward the intermediate liquid chamber 35 side when the same pressing force is applied can be obtained. It is possible to more reliably realize a configuration that is larger than the bulging deformation of the membrane 37 toward the main liquid chamber 15.

Further, since the uneven bulging portion 36 is integrally formed over the entire area of the main body portion 37b located inside the outer peripheral edge portion 37a axially sandwiched by the sandwiching member 39 in the membrane 37. , The membrane 37 can be greatly bulged and deformed toward the intermediate liquid chamber 35 side, and the damping force generated when the bound load is input and the damping force generated when the rebound load is input can be greatly different. ..
Further, since the membrane 37 is in contact with the inner peripheral edge portion of the first sandwiching portion 27, it is possible to prevent the membrane 37 from colliding with the inner peripheral edge portion of the first sandwiching portion 27 when the rebound load is input. Is possible, and the generation of abnormal noise can be reliably suppressed. Further, since the membrane 37 is in contact with the inner peripheral edge portion of the first sandwiching portion 27, a high damping force can be generated when the rebound load is input even if the vibration has a relatively small amplitude.

Next, the vibration isolator 5 according to the fifth embodiment of the present invention will be described with reference to FIG.
In the fifth embodiment, the same parts as the components in the second embodiment are designated by the same reference numerals, the description thereof will be omitted, and only the different points will be described.

In the present embodiment, a plurality of support protrusions 41 are formed on at least one of the first sandwiching portion 25 and the outer peripheral edge portion 31a of the membrane 31 so as to project and abut against the other. In the illustrated example, the support projection 41 is formed on the lower surface of the outer peripheral edge portion 31a of the membrane 31. Of the lower surface of the membrane 31 that is in contact with the upper surface of the first sandwiching portion 25, the support projection 41 receives a load from the vibration isolator 5, and the membrane 31 is deformed or displaced toward the main liquid chamber 15. When this is done, it is formed in a portion that can be separated upward from the upper surface of the first sandwiching portion 25. The support protrusion 41 is formed in a curved surface shape that protrudes downward. The plurality of support protrusions 41 are arranged on the membrane 31 at equal intervals in the radial direction and the circumferential direction.

The support projection 41 may be formed on the upper surface of the first sandwiching portion 25 as shown in FIG. Further, in the support protrusion 41, a load is input to the vibration isolator 5 among the upper surfaces of the first sandwiching portion 25 that is in contact with the lower surface of the membrane 31, and the membrane 31 is deformed toward the main liquid chamber 15. Alternatively, when displaced, the lower surface of the membrane 31 may be formed in a portion that can be separated upward. Further, the support projection 41 may be formed on both the first sandwiching portion 25 and the outer peripheral edge portion 31a of the membrane 31.

As described above, according to the anti-vibration device 5 according to the present embodiment, a plurality of the first sandwiching portion 25 and the outer peripheral edge portion 31a of the membrane 31 are in contact with each other so as to project toward the other. Since the support projection 41 of the above is formed, when a load is input to the vibration isolator 5 and the membrane 31 is deformed or displaced toward the intermediate liquid chamber 35 side, the outer peripheral edge portion 31a of the membrane 31 has a wide range. It is possible to suppress the collision with the first sandwiching portion 25 at once over the entire period, and it is possible to suppress the generated tapping sound to a small value.

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 to 5 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 devices 1 to 5 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 appropriately possible to replace the constituent elements in the above-described embodiment with well-known constituent elements without departing from the spirit of the present invention, and the above-mentioned modifications may be appropriately combined.

1, 2, 3, 4, 5 Anti-vibration device 11 1st mounting member 12 2nd mounting member 13 Elastic body 14 Liquid chamber 15 Main liquid chamber 16 Sub liquid chamber 17 Partition member 21 1st orifice passage 21a Main liquid chamber side passage 21b Intermediate liquid chamber side passage 22 Second orifice passage 23, 36 Uneven bulging part 25, 27 First pinching part 29, 38 Second pinching part 31, 37 Membrane 31a, 37a Outer peripheral edge 35 Intermediate liquid chamber 41 Support protrude

Claims (8)

A cylindrical first mounting member connected to either one of the vibration generating portion and the vibration receiving portion, and a second mounting member connected to the other.
An elastic body connecting the first mounting member and the second mounting member,
The liquid chamber in the first mounting member is provided with a partition member for partitioning the liquid chamber into a main liquid chamber and a sub liquid chamber having the elastic body as a part of a partition wall.
The partition member is
Membrane, which forms part of the partition wall of the main liquid chamber,
An intermediate liquid 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 liquid chamber.
A first orifice passage communicating the main liquid chamber and the intermediate liquid chamber,
A second orifice passage communicating the intermediate liquid chamber and the auxiliary liquid chamber,
A sandwiching member for sandwiching the outer peripheral edge portion of the membrane from both the main liquid chamber side and the intermediate liquid chamber side is provided.
The first orifice passage includes a main liquid chamber side passage located on the main liquid chamber side and an intermediate liquid chamber side passage located on the intermediate liquid chamber side, and the main liquid chamber side passage and the intermediate liquid. One of the chamber-side passages has a lower liquid flow resistance than the other passage.
The sandwiching member supports the membrane from one of the main liquid chamber and the intermediate liquid chamber, which is located on the one passage side in the flow direction of the liquid in the first orifice passage. A sandwiching portion and a second sandwiching portion that supports the membrane from the other liquid chamber side located on the other passage side in the flow direction of the liquid in the first orifice passage are provided.
The vibration isolator is characterized in that the first sandwiching portion projects longer inward in the radial direction than the second sandwiching portion. Claim 1 is characterized in that, in the inner peripheral edge portion of the first sandwiching portion, the portion with which the membrane comes into contact is gradually inclined toward the inside in the radial direction so as to be away from the other liquid chamber. Anti-vibration device described in. The vibration isolation device according to claim 2, wherein the membrane is in contact with an inner peripheral edge portion of the first sandwiching portion. The membrane includes an outer peripheral edge portion sandwiched between the sandwiching members, and a main body portion located radially inside the outer peripheral edge portion and formed to be thick.
A radial gap is provided between the outer peripheral surface of the main body portion located on the other liquid chamber side of the outer peripheral edge portion and the inner peripheral surface of the second sandwiching portion. The anti-vibration device according to any one of claims 1 to 3, wherein the vibration isolator is characterized. The membrane has a swelling portion that increases the swelling deformation toward the other liquid chamber side rather than the swelling deformation toward the one liquid chamber side when the same pressing force is applied. The anti-vibration device according to any one of claims 1 to 4, wherein the anti-vibration device is formed. The vibration isolator according to claim 5, wherein the unevenly bulging portion is formed in a curved surface shape of a protrusion toward one of the liquid chambers. The anti-vibration device according to claim 6, wherein the unevenly bulging portion projects inside the first sandwiching portion. 7. The anti-vibration device according to item 1.

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