JP2008232340A - Liquid filled vibration isolator - Google Patents

Abstract

A liquid-filled vibration isolator capable of suppressing abnormal noise caused by cavitation is provided.
An engine mount provided with a pressure receiving chamber 15a in which an internal pressure changes in response to an input of a load and an orifice passage 17 that communicates with an equilibrium chamber 15b in which a volume change is allowed by deformation of a flexible membrane. The valve for restricting the flow of the liquid through the orifice passage 17 when the flow velocity of the liquid flowing through the orifice passage 17 from the equilibrium chamber 15b toward the pressure reception chamber 15a becomes equal to or higher than a predetermined flow velocity as the internal pressure of the pressure receiving chamber 15a decreases. 20 is provided.
[Selection] Figure 2

Description

  The present invention relates to a liquid-filled vibration isolator that connects two liquid chambers by an orifice passage and obtains a vibration isolation effect by utilizing a flow resistance when the liquid flows through the orifice passage, and in particular, an engine mount for an automobile. The present invention relates to a liquid-filled type vibration isolator used for, for example.

  Patent Document 1 discloses an application of such a liquid-filled vibration isolator as an engine mount for an automobile. As shown in FIG. 6, the engine mount described in Patent Document 1 is mounted by connecting a pair of attachment portions 1 and 2 attached to a vehicle body and an engine by an elastic member 3 made of an elastic material such as rubber. A main body 4 is formed. Further, the mount body 4 is provided with a flexible film 5, and a liquid chamber 6 is formed between the recess 3 a of the elastic member 3 and the flexible film 5. The chamber 6 is partitioned into a pressure receiving chamber 6a on the elastic member 3 side and an equilibrium chamber 6b on the flexible membrane 5 side. Further, a passage extending so as to surround the partition member 7 is formed around the partition member 7. This passage is connected to the pressure receiving chamber 6a through the pressure receiving chamber side opening 7a, and is connected to the equilibrium chamber 6b through the equilibrium chamber side opening 7b, thereby communicating the pressure receiving chamber 6a and the equilibrium chamber 6b. An orifice passage 8 is formed. The pressure receiving chamber 6a, the equilibrium chamber 6b, and the orifice passage 8 are filled with an incompressible liquid such as ethylene glycol.

According to such an engine mount, the liquid flows through the orifice passage 8 when the volume of the pressure receiving chamber 6a changes as vibration is input and the elastic member 3 is deformed. As a result, the vibration is attenuated by the channel resistance generated when the liquid flows through the orifice passage 8, and a vibration isolation effect that cannot be obtained only by elastic deformation of the elastic member 3 can be obtained.
Japanese Patent Laid-Open No. 2001-50333

  By the way, in such an engine mount for automobiles, abnormal noise may be generated when a large load is instantaneously input, such as when overcoming a step on a road surface. Such abnormal noise is caused by the fact that the liquid flow between the liquid chambers 6a and 6b through the orifice passage 8 cannot follow the rapid volume change of the pressure receiving chamber 6a due to the momentary load input. It is what happens. More specifically, when the pressure receiving chamber 6a is deformed in the direction in which the volume increases, the inflow of liquid flowing into the pressure receiving chamber 6a through the orifice passage 8 with respect to the volume change amount per unit time of the pressure receiving chamber 6a. This occurs due to the relatively small amount.

  As described above, when the amount of liquid flowing into the pressure receiving chamber 6a per unit time is relatively small with respect to the volume change amount, an excessive negative pressure is generated in the pressure receiving chamber 6a and cavitation is generated. Become. And it is thought that abnormal noise is generated by the impact when the bubbles generated by the cavitation collapse and disappear.

  Further, the inventors of the present application, when a large load is instantaneously input as described above and an excessive negative pressure is generated in the pressure receiving chamber as described above, a liquid having a high flow velocity flows from the orifice passage. It was confirmed by experiments that bubbles generated by cavitation are likely to grow large, and that the generation of noise due to the collapse and disappearance of the bubbles is promoted.

  Such problems are not limited to automobile engine mounts, but are generally common in liquid-filled vibration damping devices in which a pressure receiving chamber partitioned by a partition member and an equilibrium chamber are connected by an orifice passage.

  The present invention has been made based on this finding, and an object thereof is to provide a liquid-filled vibration isolator capable of suppressing abnormal noise caused by cavitation in the liquid-filled vibration-proof device. is there.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is an elastic member that couples a pair of attachment portions attached to the vibration source and the support, a liquid chamber that is partitioned by the elastic member and a flexible film, and in which liquid is enclosed, The liquid chamber is divided into a pressure receiving chamber in which an internal pressure changes with deformation of the elastic member caused by relative displacement of the pair of mounting portions, and an equilibrium chamber in which volume change is allowed by deformation of the flexible membrane. In the liquid-filled vibration isolator having a partition member that performs communication, and an orifice passage that communicates the pressure receiving chamber and the equilibrium chamber, the orifice moves from the equilibrium chamber toward the pressure receiving chamber as the internal pressure of the pressure receiving chamber decreases. The gist is to provide a valve for restricting the flow of the liquid through the orifice passage when the flow velocity of the liquid flowing through the passage becomes a predetermined flow velocity or more.

  When a large load is momentarily input to the vibration isolator body, the volume of the pressure receiving chamber changes rapidly and its internal pressure fluctuates greatly. Get faster. Therefore, in the first aspect of the present invention, when the flow velocity of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber becomes equal to or higher than a predetermined flow velocity, the flow of the liquid through the orifice passage is limited. A valve is provided. As a result, when the volume of the pressure receiving chamber rapidly increases as a large load is instantaneously input, the flow of liquid flowing from the equilibrium chamber toward the pressure receiving chamber is restricted. For this reason, when an excessive negative pressure is generated in the pressure receiving chamber, the flow rate of the liquid flowing into the pressure receiving chamber through the orifice passage is slowed down, and it is possible to suppress the bubble generated by cavitation from growing greatly. As a result, it is possible to suppress abnormal noise caused by cavitation.

  On the other hand, when the load input to the vibration isolator body is relatively small, in other words, when the flow velocity of the liquid flowing from the equilibrium chamber toward the pressure receiving chamber is less than the predetermined flow velocity, such a restriction is not performed. In addition, the anti-vibration function of the anti-vibration device obtained by the flow path resistance of the orifice passage is not extremely reduced.

  The predetermined flow velocity, that is, the flow velocity value at the time of restricting the flow of the liquid, is set based on the flow velocity of the liquid when a sudden pressure fluctuation that causes cavitation occurs.

  According to a second aspect of the present invention, in the liquid-filled vibration damping device according to the first aspect, the flow rate of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber is greater than or equal to a predetermined flow rate. When this happens, the gist is to block the orifice passage and prohibit the flow of liquid.

  The specific mode for restricting the flow of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber is to reduce the flow rate of the liquid by reducing the passage cross-sectional area of the orifice passage. According to the invention, when the flow velocity of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber exceeds a predetermined flow velocity, the orifice passage is closed, that is, the passage cross-sectional area of the orifice passage is set to “0”. This includes those that prohibit flow. Incidentally, in order to suppress the growth of bubbles generated by cavitation by slowing the flow rate of the liquid flowing into the pressure receiving chamber, the flow rate of the liquid is made as slow as possible, that is, its flow is prohibited as in the invention of claim 2. It is desirable to do.

  According to a third aspect of the present invention, in the liquid-filled vibration damping device according to the first or second aspect, the valve includes a contact portion formed so as to protrude into the orifice passage, and the same orifice. A tongue-like valve body formed of an elastic material so as to protrude into the orifice passage at a portion spaced from the contact portion in the passage toward the equilibrium chamber in the liquid flow direction. When the flow rate of the liquid flowing from the equilibrium chamber toward the pressure receiving chamber exceeds a predetermined flow rate, the elastically deformed valve body comes into contact with the contact portion, thereby reducing the cross-sectional area of the orifice passage. The gist is to limit the flow of the liquid.

  Specifically, as in the third aspect of the present invention, a tongue-like valve body formed of an elastic material and provided protruding from the orifice passage, and elastic deformation as the liquid flow rate increases. It is possible to adopt a configuration in which the valve is formed by the abutting portion formed so as to project into the orifice passage so that the valve body abuts. According to such a configuration, the valve body, which is elastically deformed as the flow velocity of the liquid flowing in the orifice passage from the equilibrium chamber toward the pressure receiving chamber increases, comes into contact with the contact portion, whereby the passage of the orifice passage is interrupted. The area can be reduced to restrict the flow of the liquid.

  According to a fourth aspect of the present invention, in the liquid-filled type vibration damping device according to the first or second aspect, the valve is provided in the equilibrium chamber side opening in the vicinity of the equilibrium chamber side opening of the orifice passage in the equilibrium chamber. And the flow rate of the liquid flowing into the orifice passage through the equilibrium chamber side opening becomes equal to or higher than a predetermined flow rate as the internal pressure of the pressure receiving chamber decreases. The gist of the invention is to restrict the flow of the liquid by reducing the cross-sectional area of the orifice passage by elastic deformation so as to cover the equilibrium chamber side opening.

  Further, according to the invention described in claim 4, the valve body formed in a plate shape by an elastic member is provided in the vicinity of the equilibrium chamber side opening of the orifice passage in the equilibrium chamber so as to face the equilibrium chamber side opening. Can also be adopted. According to such a configuration, the valve body formed so as to face the equilibrium chamber side opening of the orifice passage flows through the gap between the valve body and the equilibrium chamber side opening and flows into the orifice passage through the equilibrium chamber side opening. As the flow rate of the liquid increases, the liquid is elastically deformed so as to be attracted to the equilibrium chamber side opening. Therefore, when the flow rate of the liquid flowing into the equilibrium chamber side opening becomes equal to or higher than a predetermined flow rate at which the valve body begins to be elastically deformed, the flow of the liquid in the orifice passage is restricted. Thus, according to the configuration described in claim 4, when the flow velocity of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber becomes equal to or higher than the predetermined flow velocity, the passage sectional area of the orifice passage is reduced. It becomes possible to restrict the flow of the liquid.

  A fifth aspect of the present invention is the liquid-filled vibration isolator according to any one of the first to fourth aspects, wherein the liquid mount type vibration isolator is applied as an engine mount for an automobile that supports the engine on a vehicle body. The gist.

  In the case of an engine mount for automobiles, abnormal noise may be generated when a large load is instantaneously input, such as when overcoming a step on a road surface. In particular, in automobiles that require quietness, it is required to suppress such abnormal noise. Therefore, according to the invention described in claim 5, by applying the liquid filled type vibration damping device according to any one of claims 1 to 4 as an engine mount for an automobile that supports the engine on the vehicle body, Generation of abnormal noise can be suitably suppressed.

(First embodiment)
Hereinafter, a first embodiment in which a liquid-filled vibration isolator according to the present invention is embodied in an automobile engine mount that supports an engine on a vehicle body will be described with reference to FIGS.

  FIG. 1 shows a cross-sectional structure of an engine mount according to this embodiment. As shown in FIG. 1, the mount body 10 of this engine mount is formed by connecting a vehicle body side mounting member 11 fixed to the vehicle body and an engine side mounting member 12 connected to the engine via an elastic member 13. Is formed.

  The vehicle body side mounting member 11 includes a bottom member 11a connected to the vehicle body by a bolt 50 and a cylindrical member 11b. As shown in FIG. 1, the bottom member 11a and the cylindrical member 11b are integrally connected by caulking. By doing so, it is formed in a bottomed cylindrical shape. The inner peripheral surface of the cylindrical member 11b is vulcanized and bonded to the outer peripheral surface of the bottomed cylindrical elastic member 13 formed of an elastic material such as rubber. A disk-like engine side mounting member 12 to which a bolt 51 for connecting the engine and a positioning pin 52 are mounted is vulcanized and bonded to the upper end portion of the elastic member 13.

  As shown in FIG. 1, the mount main body 10 thus formed has a space defined by an inner peripheral surface of the elastic member 13 and an inner peripheral surface of the vehicle body side mounting member 11. A flexible film 14 and a partition member 16 that divide the space are sandwiched between the bottom member 11a and the cylindrical member 11b. The flexible film 14 is made of an easily deformable material such as rubber, and is sandwiched between the bottom member 11a and the cylindrical member 11b in a sufficiently bent state. An incompressible liquid such as ethylene glycol is sealed in a space defined by the flexible film 14 and the inner peripheral surface of the elastic member 13 to form a liquid chamber 15. The liquid chamber 15 is partitioned by a partition member 16 into a pressure receiving chamber 15a on the elastic member 13 side and an equilibrium chamber 15b on the flexible membrane 14 side as shown in FIG.

  The partition member 16 is formed by overlapping an outer peripheral hat member 16a having a hat shape protruding toward the pressure receiving chamber 15a and an inner peripheral hat member 16b having a smaller diameter than the outer peripheral hat member 16a. . And as FIG. 1 shows, the orifice channel | path 17 extended in the circumferential direction of the division member 16 is formed between the outer peripheral side hat member 16a and the inner peripheral side hat member 16b. The orifice passage 17 is connected to the pressure receiving chamber 15a through a pressure receiving chamber side opening 16c formed in the outer peripheral side hat member 16a, and is connected to the equilibrium chamber 15b through an equilibrium chamber side opening 16d formed in the inner peripheral side hat member 16b. It is connected. Thus, the pressure receiving chamber 15a and the equilibrium chamber 15b are connected to each other through the orifice passage 17.

  In this engine mount in which the pressure receiving chamber 15a and the equilibrium chamber 15b are connected to each other by the orifice passage 17 as described above, relative displacement between the vehicle body side mounting member 11 and the engine side mounting member 12 in accordance with the input of a load. When the volume of the pressure receiving chamber 15a changes, the liquid flows through the orifice passage 17. Therefore, the vibration can be attenuated by the flow path resistance of the orifice passage 17, and an anti-vibration effect that cannot be obtained only by elastic deformation of the elastic member 13 can be obtained.

  By the way, in such an engine mount, abnormal noise may be generated when a large load is instantaneously input, such as when overcoming a step on a road surface. Such an abnormal noise is generated when the pressure receiving chamber 15a is deformed in a direction in which the volume increases in response to an instantaneous load input, with respect to the volume change amount per unit time of the pressure receiving chamber 15a. This occurs due to the relatively small inflow amount of the liquid flowing into the pressure receiving chamber 15a. As described above, when the inflow amount of the liquid per unit time into the pressure receiving chamber 15a becomes relatively small with respect to the volume change amount, an excessive negative pressure is generated in the pressure receiving chamber 15a to cause cavitation. And the noise generated by the impact when the bubbles generated by the cavitation collapse and disappear.

  Further, the inventors of the present application, when a large load is instantaneously input and an excessive negative pressure is generated in the pressure receiving chamber 15a, the flow velocity of the liquid flowing through the orifice passage 17 becomes very fast, and the orifice passage 17 Cavitation is likely to occur in the orifice passage 17 and in the vicinity of the downstream side of the pressure receiving chamber side opening 16c (portion A surrounded by a broken line in FIG. 1) where the pressure in the inside is further reduced. Was confirmed by experiments.

  When bubbles generated by such cavitation flow with a liquid into a pressure-receiving chamber where excessive negative pressure is generated, the bubbles are likely to grow large, and the generation of noise due to the collapse and disappearance of the bubbles is encouraged. become.

  Therefore, in the engine mount according to the present embodiment, the flow rate of the liquid flowing in the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a is greater than or equal to a predetermined flow rate in order to suppress abnormal noise caused by such cavitation. When this happens, a valve 20 for restricting the flow is provided.

  Hereinafter, the configuration of the valve 20 will be described in detail with reference to FIG. 2A is an enlarged sectional view showing the orifice passage 17 near the valve 20, and FIG. 2B is a sectional view taken along the line bb in FIG. 2A.

  As shown in FIG. 2A, the valve 20 includes a contact portion 21 and a valve body 22 that project into the orifice passage 17. As shown in FIG. 2B, the contact portion 21 is formed in a plate shape extending so as to protrude from the inner circumferential side hat member 16 b into the orifice passage 17. A gap through which the liquid flows is formed between the tip 21a and the outer peripheral side hat member 16a. On the other hand, the valve body 22 formed of an elastic material such as rubber is located in a portion of the orifice passage 17 that is separated from the contact portion 21 toward the equilibrium chamber side (left side in FIG. 3B) in the liquid flow direction. Is provided. The valve body 22 formed in a tongue-like shape so as to protrude into the orifice passage 17 has a base end 22b vulcanized and bonded to the outer peripheral side hat member 16a. A gap through which the liquid flows is formed between the tip 22a and the inner circumferential hat member 16b.

  As shown in FIG. 2A, the contact portion 21 and the valve body 22 are formed over substantially the entire width of the orifice passage 17, and the projection surface combining the contact portion 21 and the valve body 22 has an orifice. Most of the passage cross section of the passage 17 is covered.

  The operation of the valve 20 constituted by the contact portion 21 and the valve body 22 provided in the orifice passage 17 will be described with reference to FIG. FIG. 3 shows an operation mode of the valve 20 when a large load is instantaneously input to the mount body 10, that is, when the flow velocity of the liquid flowing in the orifice passage 17 with the volume change of the pressure receiving chamber 15a is equal to or higher than a predetermined flow velocity. FIG. 3A is a cross-sectional view showing a state in which the liquid flows from the equilibrium chamber 15b toward the pressure receiving chamber 15a, and FIG. 3B shows a state in which the liquid flows from the pressure receiving chamber 15a toward the equilibrium chamber 15b. It is sectional drawing which shows a mode.

  As the load is input, the pressure receiving chamber 15a is deformed so that its volume increases, and the liquid flows in the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a as indicated by an arrow in FIG. In this case, the valve body 22 is elastically deformed so that the portion on the tip 22a side comes into contact with the contact portion 21. As a result, the orifice passage 17 is substantially closed, and the liquid flow through the orifice passage 17 is substantially prohibited.

  Further, when the volume of the pressure receiving chamber 15a is reduced, and the liquid in the orifice passage 17 flows from the pressure receiving chamber 15a toward the equilibrium chamber 15b along with this, the valve element 22 is moved as shown in FIG. It is elastically deformed so as to be separated from the contact portion 21. Therefore, when the liquid flows through the gap between the contact portion 21 and the valve body 22 and is deformed in a direction in which the volume of the pressure receiving chamber 15a is reduced, the mount body 10 is prevented from being highly dynamic springs. The vibration isolation effect can be obtained by utilizing the flow path resistance of the orifice passage 17.

  On the other hand, when the load input to the mount body 10 is relatively small, in other words, when the flow rate of the liquid flowing from the equilibrium chamber 15b toward the pressure receiving chamber 15a is less than a predetermined flow rate, the rigidity of the valve body 22 causes the FIG. As shown in (b), the state where the contact portion 21 and the valve body 22 are separated is maintained. Therefore, as shown by the arrows and the broken line arrows, the flow of the liquid to both the pressure receiving chamber 15a side and the equilibrium chamber 15b side is allowed, and such a flow restriction is not performed.

  The predetermined flow velocity, that is, the flow velocity value that restricts the flow of the liquid is set based on the flow velocity value of the liquid when a sudden pressure fluctuation that causes cavitation occurs. In the present embodiment, the distance between the valve body 22 and the contact portion 21 is adjusted, and the thickness of the valve body 22 and the material are changed to adjust the rigidity thereof, thereby adjusting the orifice passage 17 from the equilibrium chamber 15b. When the flow rate of the liquid flowing toward the pressure receiving chamber 15a becomes equal to or higher than a predetermined flow rate, the valve body 22 comes into contact with the contact portion 21 so that the valve 20 is closed.

According to the first embodiment described above, the following effects can be obtained.
(1) When a large load is momentarily input to the mount body 10, the volume of the pressure receiving chamber 15a rapidly changes and its internal pressure fluctuates greatly. Therefore, the liquid flowing through the orifice passage 17 in accordance with the fluctuation of the internal pressure The flow rate of is very fast. Therefore, in the first embodiment, the valve that restricts the flow of the liquid through the orifice passage 17 when the flow velocity of the liquid flowing through the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a exceeds a predetermined flow velocity. 20 is provided. As a result, when the volume of the pressure receiving chamber 15a rapidly increases as a large load is instantaneously input, the flow of liquid flowing from the equilibrium chamber 15b toward the pressure receiving chamber 15a is limited. Therefore, when an excessive negative pressure is generated in the pressure receiving chamber 15a, the flow rate of the liquid flowing into the pressure receiving chamber 15a through the orifice passage 17 becomes slow, and it is possible to suppress the bubble generated by cavitation from growing greatly. It becomes like this. As a result, it is possible to suppress abnormal noise caused by cavitation.

  On the other hand, when the liquid flows from the pressure receiving chamber 15a toward the equilibrium chamber 15b, or when the load input to the mount body 10 is relatively small, in other words, the flow velocity of the liquid flowing from the equilibrium chamber 15b toward the pressure receiving chamber 15a. Is not less than the predetermined flow rate, such a restriction is not performed, so that the vibration-proof function obtained by the flow path resistance of the orifice passage 17 is not extremely lowered.

  (2) In the first embodiment, when the flow velocity of the liquid flowing through the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a becomes equal to or higher than a predetermined flow velocity, the orifice passage 17 is closed to substantially prevent the liquid flow. Is prohibited. Therefore, the growth of bubbles generated by cavitation can be suitably suppressed by reducing the flow rate of the liquid flowing into the pressure receiving chamber 15a as much as possible.

The first embodiment can also be implemented in the following forms that are appropriately modified.
-Although the structure which provided the contact part 21 in the inner peripheral side hat member 16b and provided the valve body 22 in the outer peripheral side hat member 16a was shown, while providing the contact part 21 in the outer peripheral side hat member 16a, the inner peripheral side The structure which provides the valve body 22 in the hat member 16b is also employable.

  Further, although the plate-like contact portion 21 that protrudes from the inner circumferential side hat member 16b and forms a gap through which fluid flows between the tip 21a and the outer circumferential side hat member 16a is shown, the shape of the contact portion 21 Is not limited to such a configuration. When the valve body 22 is separated from the contact portion 21, the liquid flow is allowed, while when the valve body 22 and the contact portion 21 are in contact with each other, the orifice passage 17 is closed to prohibit the liquid flow. Any configuration can be used. For example, a partition plate that closes the orifice passage 17 is provided, a through hole that allows liquid flow is formed in the partition plate, and this partition plate is used as a contact portion, and the valve body 22 contacts the contact portion. It is also possible to employ a configuration in which liquid flow is prohibited by closing the through hole.

In the first embodiment, the configuration in which the flow of the liquid is substantially prohibited by closing the orifice passage 17 when the flow velocity of the liquid flowing in the orifice passage 17 becomes equal to or higher than a predetermined flow velocity. On the other hand, if the flow of the liquid flowing in the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a can be suppressed, the flow rate of the liquid flowing into the pressure receiving chamber 15a is reduced, and bubbles generated by cavitation are generated. It will be possible to suppress the growth of. Therefore, in addition to the one that completely blocks the flow of the liquid, a configuration that partially restricts the flow of the liquid can be employed. For example, even when the valve body is elastically deformed and abuts against the abutting portion, the valve body and the abutting portion smaller than the passage cross-sectional area of the orifice passage 17 are formed so as to generate a gap through which the liquid flows. A configuration can also be adopted.
(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to FIGS. 4 and 5. Since this embodiment is different from the first embodiment in the configuration of a valve for restricting the flow of liquid in the orifice passage 17, the same members are only given the same reference numerals and the description thereof is omitted. The description will focus on the configuration of the valve, which is the difference between the two.

  FIG. 4 shows a cross-sectional structure of an engine mount according to the second embodiment. As shown in FIG. 4, in the engine mount of this embodiment, a valve 120 is provided in the equilibrium chamber 15b instead of the valve 20 formed in the orifice passage 17 in the first embodiment. The valve 120 formed of an elastic material includes a valve body 121 formed in a plate shape near the equilibrium chamber side opening 16 d of the orifice passage 17, and a support portion formed in a column shape between the valve body 121 and the partition member 16. 122.

  Hereinafter, the configuration of the valve 120 will be described in more detail with reference to FIG. FIGS. 5A and 5B are enlarged perspective views showing the vicinity of the valve 120 in the equilibrium chamber 15b, and FIG. 5A shows the valve 120 in the opened state. These are enlarged views of the valves 120 in the closed state.

  As shown in FIG. 5A, the valve body 121 having the base end 121a vulcanized and bonded to the partition member 16 extends so as to face the equilibrium chamber side opening 16d formed in the partition member 16, and the equilibrium chamber It is formed in a bowl shape so as to cover the side opening 16d. The support portion 122 is formed in a pair of pillars so that the valve body 121 is separated from the partition member 16 by a predetermined distance, one end being the partition member 16 and the other end being the tip 121b of the valve body 121. Is vulcanized and bonded. For this reason, a gap through which the liquid flows is formed between the valve body 121 and the partition member 16.

  In the valve 120 formed in this way, the valve body 121, the partition member 16, and the valve member 15a as shown by an arrow in FIG. 5A as the pressure receiving chamber 15a is deformed so that the volume thereof increases. The liquid flows through the gap between them and flows into the orifice passage 17 from the equilibrium chamber side opening 16d.

  Here, when a large load is input to the mount body 10 and the volume of the pressure receiving chamber 15a is rapidly increased, that is, when the flow velocity of the liquid flowing into the orifice passage 17 through the equilibrium chamber side opening 16d becomes a predetermined flow velocity or more. 5 (b), the valve body 121 is attracted to the equilibrium chamber side opening 16d, and the valve body 121 and the support part 122 are elastically deformed, so that the valve body 121 is opened to the equilibrium chamber side of the partition member 16. It comes in close contact with the peripheral edge of 16d. As a result, the orifice passage 17 is blocked, and the flow of liquid in the orifice passage 17 is prohibited.

  Further, when the volume of the pressure receiving chamber 15a is reduced and the liquid in the orifice passage 17 flows from the pressure receiving chamber 15a toward the equilibrium chamber 15b along with this, the orifice passage 17 enters the equilibrium chamber 15b through the equilibrium chamber side opening 16d. The valve body 121 is deformed so as to be separated from the partition member 16 by the action of the flowing liquid. Therefore, the liquid flows through the gap between the valve body 121 and the partition member 16, and the liquid flow through the orifice passage 17 is allowed. Accordingly, when the pressure receiving chamber 15a is deformed in a direction in which the volume is reduced, it is possible to suppress the high dynamic spring of the mount body 10 and obtain a vibration isolation effect using the flow path resistance of the orifice passage 17. it can.

  On the other hand, when the load input to the mount body 10 is relatively small, in other words, the volume of the pressure receiving chamber 15a increases relatively slowly, and the flow rate of the liquid flowing into the orifice passage 17 through the equilibrium chamber side opening 16d is a predetermined flow rate. If it is less, the valve body 121 is maintained in a state of being separated from the partition member 16 by the rigidity of the valve body 121 and the support portion 122 as shown in FIG. Therefore, the flow of the liquid to both the equilibrium chamber 15b side and the pressure receiving chamber 15a side through the orifice passage 17 is allowed, and the flow restriction as described above is not performed.

  The predetermined flow velocity, that is, the flow velocity value that restricts the flow of the liquid is set based on the flow velocity value of the liquid when a sudden pressure fluctuation that causes cavitation occurs. In the present embodiment, the distance between the valve body 121 and the partition member 16 is adjusted, and the thickness and material of the valve body 121 and the support portion 122 are changed to adjust the rigidity thereof, thereby adjusting the orifice through the equilibrium chamber side opening 16d. When the flow rate of the liquid flowing into the passage 17 becomes equal to or higher than a predetermined flow rate, the equilibrium chamber side opening 16d is closed to prohibit the flow of the liquid in the orifice passage 17.

According to the second embodiment described above, the following effects can be obtained.
(3) A valve body 121 formed in a plate shape by an elastic material is provided near the equilibrium chamber side opening 16d in the equilibrium chamber 15b so as to face the equilibrium chamber side opening 16d. Therefore, as the flow velocity of the liquid flowing through the gap between the valve body 121 and the partition member 16 and flowing into the orifice passage 17 through the equilibrium chamber side opening 16d increases, the valve body 121 is attracted to the equilibrium chamber side opening 16d. It is elastically deformed. Accordingly, when the flow rate of the liquid flowing into the equilibrium chamber side opening 16d becomes equal to or higher than a predetermined flow rate, the flow of the liquid in the orifice passage 17 is restricted. As a result, when the flow rate of the liquid flowing through the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a becomes equal to or higher than a predetermined flow rate, the flow of the liquid in the orifice passage 17 can be restricted. Therefore, when an excessive negative pressure is generated in the pressure receiving chamber 15a, the flow rate of the liquid flowing in through the orifice passage 17 becomes slow, and it is possible to suppress the bubble generated by cavitation from growing greatly. As a result, it is possible to suppress abnormal noise caused by cavitation.

  (4) When the flow rate of the liquid flowing into the orifice passage 17 through the equilibrium chamber side opening 16d becomes equal to or higher than a predetermined flow rate, the orifice passage 17 is closed to inhibit the flow of the liquid. Therefore, when an excessive negative pressure is generated in the pressure receiving chamber 15a, the flow rate of the liquid flowing in through the orifice passage 17 can be made as slow as possible, and the bubble growth generated by cavitation can be suitably suppressed.

  (5) In the first embodiment, in order to provide the valve 20 in the orifice passage 17, it is necessary to separately provide the contact portion 21 in addition to the valve body 22, but in this embodiment, the balancing member side of the partition member 16 is provided. Since the valve body 121 is brought into contact with the peripheral edge of the opening 16d, it is not necessary to provide a separate contact portion. Therefore, the configuration of the valve can be simplified.

The second embodiment can also be carried out in the following forms that are appropriately modified.
In the second embodiment, when the flow velocity of the liquid flowing through the gap between the valve body 121 and the partition member 16 and flowing into the orifice passage 17 through the equilibrium chamber side opening 16d becomes equal to or higher than the predetermined flow velocity, the orifice passage A configuration in which the liquid 17 is closed to inhibit the flow of the liquid is shown. On the other hand, if the flow of the liquid flowing in the orifice passage 17 from the equilibrium chamber 15b toward the pressure receiving chamber 15a can be suppressed, the orifice passage 17 can be used when an excessive negative pressure is generated in the pressure receiving chamber 15a. It is possible to suppress the growth of bubbles generated by cavitation by slowing the flow rate of the liquid flowing in through the cavitation. Therefore, in addition to the one that completely blocks the flow of the liquid, a configuration that partially restricts the flow of the liquid can be employed. For example, even when the valve body 121 is elastically deformed and comes into contact with the peripheral edge of the equilibrium chamber side opening 16d of the partitioning member 16, the valve body 121 is made small so that a gap through which liquid flows is generated. A configuration in which at least a part of the opening 16d is covered, or a configuration in which a through hole serving as a restriction passage having a smaller opening area than the equilibrium chamber side opening 16d is provided in the valve body 121 may be employed. Further, a configuration in which a spacer is provided between the valve body 121 and the partition member 16 so that the valve body 121 does not completely contact the peripheral edge portion of the equilibrium chamber side opening 16d may be employed.

  -The rigidity of the valve body 121 can be adjusted and the support part 122 can also be abbreviate | omitted. That is, when the volume of the pressure receiving chamber 15a increases relatively slowly and the flow rate of the liquid flowing into the orifice passage 17 through the equilibrium chamber side opening 16d is less than a predetermined flow rate, the valve body 121 is divided only by its rigidity. It is also possible to adopt a configuration in which a state of being separated from the head is maintained.

Moreover, the said 1st and 2nd embodiment can also be implemented in the following embodiment which changed this suitably.
If the flow rate of the liquid flowing in the orifice passage from the equilibrium chamber 15b toward the pressure receiving chamber 15a becomes equal to or higher than a predetermined flow rate, the configuration of the valve is changed as appropriate. be able to. For example, a sensor that detects the flow rate of the liquid flowing in the orifice passage 17 and an electromagnetic valve that is electrically driven and closes the orifice passage 17 based on the fact that the flow rate detected by the sensor is equal to or higher than a predetermined flow rate. It is also possible to adopt a configuration such as providing.

  In the first and second embodiments, the example in which the liquid-filled vibration isolator according to the present invention is embodied in an engine mount for an automobile is shown. However, the present invention relates to a vibration isolator that connects a transmission to a vehicle body. It can also be applied to devices and the like. In addition, the present invention is not limited to a vibration isolator for automobiles, and can be widely applied to a liquid-filled vibration isolator in which a pressure receiving chamber and an equilibrium chamber partitioned by a partition member are connected by an orifice passage.

1 is a cross-sectional view of an engine mount according to a first embodiment of the present invention. (A) And (b) is sectional drawing of the orifice channel | path in the valve vicinity of the engine mount concerning 1st Embodiment. (A) And (b) is sectional drawing which shows the operation | movement aspect of the valve concerning the embodiment. Sectional drawing of the engine mount concerning 2nd Embodiment of this invention. (A) And (b) is a perspective view which expands and shows the valve vicinity of the engine mount concerning the embodiment. Sectional drawing of a general engine mount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mount main body, 11 ... Car body side attaching member, 12 ... Engine side attaching member, 13 ... Elastic member, 14 ... Flexible film, 15 ... Liquid chamber, 15a ... Pressure receiving chamber, 15b ... Equilibrium chamber, 16 ... Partition member 16c: pressure receiving chamber side opening, 16d: equilibrium chamber side opening, 17 ... orifice passage, 20 ... valve, 21 ... contact portion, 22 ... valve body, 120 ... valve, 121 ... valve body.

Claims (5)

An elastic member that couples a pair of attachment portions attached to the vibration source and the support, a liquid chamber that is partitioned by the elastic member and a flexible film, and in which a liquid is enclosed, and the liquid chamber is connected to the pair of attachment portions A partition member partitioned into a pressure receiving chamber in which an internal pressure changes with deformation of the elastic member caused by relative displacement of the elastic member, and an equilibrium chamber in which volume change is allowed by deformation of the flexible membrane, and the pressure receiving chamber; In a liquid-filled vibration isolator having an orifice passage communicating with the equilibrium chamber,
A valve for restricting the flow of the liquid through the orifice passage when the flow velocity of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber becomes a predetermined flow velocity or more as the internal pressure of the pressure receiving chamber decreases. A liquid-filled vibration isolator characterized by that. The liquid-filled vibration isolator according to claim 1,
The valve closes the orifice passage and inhibits the flow of the liquid when the flow velocity of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber becomes equal to or higher than a predetermined flow velocity. Liquid-filled vibration isolator. In the liquid-filled vibration isolator according to claim 1 or 2,
The valve protrudes into the orifice passage at a position spaced from the contact portion formed in the orifice passage and from the contact portion in the orifice passage toward the equilibrium chamber in the liquid flow direction. And a tongue-like valve body made of an elastic material, and elastically deformed when the flow rate of the liquid flowing through the orifice passage from the equilibrium chamber toward the pressure receiving chamber exceeds a predetermined flow rate. When the valve body abuts on the abutting portion, the flow cross-sectional area of the orifice passage is reduced to restrict the flow of the liquid. In the liquid-filled vibration isolator according to claim 1 or 2,
The valve is formed of a valve body formed in a plate shape by an elastic material so as to face the equilibrium chamber side opening in the vicinity of the equilibrium chamber side opening of the orifice passage in the equilibrium chamber, and as the internal pressure of the pressure receiving chamber decreases. When the flow velocity of the liquid flowing into the orifice passage through the equilibrium chamber side opening becomes equal to or higher than a predetermined flow velocity, the passage cross-sectional area of the orifice passage is reduced by elastically deforming so as to cover the equilibrium chamber side opening. A liquid-filled vibration isolator characterized by restricting the flow of liquid. The liquid-filled vibration isolator according to claim 1, which is applied as an engine mount for an automobile that supports an engine on a vehicle body.

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