JP3692919B2 - Liquid filled vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid-filled vibration isolator formed so as to cut off vibrations in a specific frequency range, and in particular, for the purpose of cutting off vibrations in two frequency ranges such as an engine idling vibration and an engine shake. The present invention relates to a liquid-filled vibration isolator in which the diaphragm and the orifice are provided at a partition member that partitions the main chamber and the sub chamber.
[0002]
[Prior art]
Among anti-vibration devices, especially in the case of engine mounts for automobiles, the engine as the power source is used under various conditions from idling to the maximum rotational speed. Therefore, it must be able to handle a wide range of frequencies. For this purpose, an anti-vibration mechanism comprising a diaphragm, a working chamber, etc. formed so as to provide two liquid chambers inside and connect between them with an orifice and to freely vibrate against fluctuations in the liquid pressure in the liquid chamber. A switchable liquid-filled vibration isolator having a switch has been devised, and is already known, for example, from Japanese Utility Model Laid-Open No. 4-77041.
[0003]
[Problems to be solved by the invention]
By the way, the above-mentioned conventional one, for example, for the input of engine idling vibration, introduces an atmospheric pressure into the working chamber, opens the working chamber to the atmosphere, and partitions the working chamber. Is maintained in a free vibration state. Thus, the hydraulic pressure fluctuation in the main chamber is absorbed by the free vibration of the second diaphragm with respect to the input of the engine idling vibration, and the engine idling vibration is absorbed and cut off. In addition, for engine shake that is in a lower frequency range than engine idling vibration, negative pressure is introduced into the working chamber to suck the second diaphragm so that the second diaphragm is not operated. Is. As a result, with respect to the fluid pressure fluctuation in the main chamber related to the engine shake, the liquid in the main chamber is actively flowed into the orifice so as to obtain a high attenuation characteristic. Thus, in the above-mentioned conventional one, the orifice is made to function only as a damping force exerting mechanism for engine shake damping. In addition, if the second diaphragm is provided separately from the first diaphragm separating the sub chamber and the air chamber, the entire manufacturing cost including assembly workability and parts management is increased. There is a problem that it must be. In order to solve such problems, the orifice contributes to the damping action of engine idling vibration, and the first diaphragm and the second diaphragm are integrated to reduce the overall manufacturing cost. An object (problem) of the present invention is to provide a liquid-filled vibration isolator that can be realized.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the following measures are taken in the present invention. That is, in the first aspect of the invention, the first connecting member attached to the vibrating body, the second connecting member attached to the vehicle body side member, the first connecting member and the second connecting member, A rubber-like insulator that absorbs and blocks vibrations from the vibrating body, a main chamber in which a chamber wall is formed by a part of the insulator and in which a liquid is enclosed, and the main chamber A sub-chamber connected to the first chamber through a first orifice and partly formed by a first diaphragm, a partition member separating the main chamber and the sub-chamber, and negative pressure or atmospheric pressure Oite but the second diaphragm and the liquid-filled vibration damping device comprising a partitioning forming between the working chamber and the main chamber to be introduced as appropriate, introduces a negative pressure into the working chamber to the engine idling vibrations And the engine eye The engine shake having a lower frequency than the ring vibration is provided with control means for controlling the atmospheric pressure to be introduced into the working chamber, and the first orifice has a negative pressure introduced into the working chamber. The first diaphragm in which the liquid in the first orifice is set to resonate with respect to the engine idling vibration in the state, and the second diaphragm that defines the working chamber defines the sub chamber. Rather, a configuration is adopted in which the flexural deformation rigidity has a high value.
[0005]
By adopting such a configuration, in the present invention, the damping function for the engine shake is exhibited by one orifice, and the liquid in the orifice is caused to resonate with respect to engine idling vibration. As a result, the dynamic spring constant in the frequency range can be reduced. As a result, in one orifice, called absorption and blocking of the damping and engine idling vibration of d Njinsheku, it is possible to perform the damping action of the two vibrating.
[0006]
Next, the invention described in claim 2 will be described. The basic point of this is the same as that of the first aspect. That is, in the present invention, the liquid-filled vibration isolator according to claim 1 is provided with a third liquid chamber between the second diaphragm and the main chamber, and the third liquid chamber and the main chamber. A configuration was adopted in which a second orifice through which a liquid flows was provided. By adopting such a configuration, in the present invention, the second orifice is adjusted mainly for the purpose of blocking engine idling vibration, and the first orifice is adjusted for the purpose of absorbing and blocking engine shake. Thus, both vibrations of the engine shake and engine idling can be efficiently absorbed and cut off.
[0007]
Next, an invention according to claim 3 will be described. The basic point of this is the same as that of the second aspect. That is, according to the present invention, in the liquid-filled vibration isolator according to claim 2, the liquid existing in the first orifice and the liquid existing in the second orifice have a higher frequency than normal engine idling vibration. Is set so as to be coupled to the vibration at the time of engine idling up , and the control means controls the atmospheric pressure to be introduced into the working chamber against the vibration at the time of engine idling up. It was decided to adopt such a configuration.
[0008]
By adopting such a configuration, in the present invention, the dynamic spring constant in the liquid-sealed vibration isolator is reduced overall in the entire frequency range, and at two locations in the engine idling frequency range. A reduction range (bottom) of the dynamic spring constant can be obtained in the specific frequency range. As a result, in addition to the normal idling vibration, the dynamic spring constant can be reduced also in the frequency range at the time of idling up by the operation of the auxiliary devices. In other words, it is possible to cope with vibration isolation in two cases of normal idling vibration and vibration at idling up.
[0009]
Next, an invention according to claim 4 will be described. The basic point of this is the same as that of the first to third aspects. That is, in the present invention, the liquid filled type vibration isolator according to claims 1 to 3 has a configuration in which the first diaphragm and the second diaphragm are integrally formed. By adopting such a configuration, in the present invention, it becomes possible to reduce the manufacturing cost of the above two diaphragms, and thus the manufacturing cost of the entire liquid-sealed vibration isolator as a whole. Can be reduced. That is, for example, the two diaphragms can be molded together by an appropriate integral molding means, and the overall manufacturing cost including part management can be reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. As for the first embodiment, the configuration includes a first connecting member 91 attached to the vibrating body side, a second connecting member 95 attached to a vehicle body side member, etc., as shown in FIG. A rubber-like insulator 8 that is between the first connecting member 91 and the second connecting member 95 and blocks vibrations from the vibrator, and is provided in series with the insulator 8 and is incompressible. A main chamber 6 and a sub chamber 7 in which a liquid, which is a fluid, is sealed, a first orifice 5 through which liquid flows between the main chamber 6 and the sub chamber 7, and a space between the main chamber 6 and the sub chamber 7 Is formed at the partition member 3 that partitions the air chamber 4 and forms a part of the chamber wall of the sub chamber 7 and the air chamber 4. The first diaphragm 41 and the partition member A second diaphragm 2 that is provided at a communication passage 31 formed in the main chamber 6 and vibrates in accordance with a fluid pressure fluctuation of the liquid in the main chamber 6 and partitions the working chamber described below, A part of the chamber wall is formed by the second diaphragm 2, and a working chamber 1 into which negative pressure or atmospheric pressure is appropriately introduced, and atmospheric pressure or a constant negative pressure into the working chamber 1 are applied. It is basically composed of switching means 11 that appropriately performs switching operation so as to be introduced.
[0011]
In such a configuration, the dimension of the first orifice 5 is when the second diaphragm 2 is in a negative pressure suction state, and in such a state, the main chamber When the engine idling vibration is propagated to the liquid in the liquid 6, the liquid existing in the first orifice 5 is set to resonate. That is, the first orifice 5 generally has a frequency (frequency) at the time of engine idling under a predetermined expansion dynamic spring constant mainly determined by an insulator 8 that forms a part of the chamber wall of the main chamber 6. The diameter or length is set so that the liquid in the first orifice 5 resonates at a specific frequency of 15 Hz to 18 Hz. On the other hand, the bending deformation rigidity of the second diaphragm 2 when the working chamber 1 is in the open air state is higher than that of the first diaphragm 41, and the input of the engine shake. Sometimes, the liquid in the main chamber 6 has a rigidity value sufficient to flow toward the sub chamber 7 via the first orifice 5. Thus, the flexural deformation rigidity value of the second diaphragm 2 is an insulator that forms a part of the chamber wall of the main chamber 6 in consideration of the flow of liquid into the first orifice 5 at the time of engine shake input. The value is appropriately set in consideration of the deformation rigidity value of 8.
[0012]
Therefore, when the working chamber 1 is open to the atmosphere, the second diaphragm 2 is placed in a state where it is less likely to bend and deform than the first diaphragm 41. As a result, vibration input to the liquid in the main chamber 6 (main (Engine shake), the liquid pressure in the main chamber 6 is likely to increase, and the liquid in the main chamber 6 flows to the sub chamber 7 side through the first orifice 5. Further, the first diaphragm 41 and the second diaphragm 2 having such a configuration have a disc-shaped second diaphragm 2 in the center as shown in FIG. 1, and an annular shape (ring shape) around the second diaphragm 2. The first diaphragm 41 is provided. And these are integrally formed by a predetermined integral molding means. Accordingly, the number of parts for the diaphragm assembly including the first diaphragm 41 and the second diaphragm 2 is reduced, and the overall manufacturing cost including the parts management cost and the assembly man-hour is reduced.
[0013]
The switching means 11 for switching operation so as to appropriately introduce the atmospheric pressure or the negative pressure into the working chamber 1 defined by the second diaphragm 2 having such a configuration is formed mainly by a three-way valve. In addition, a solenoid mechanism or the like for performing the switching operation of the three-way valve is further added. The switching operation of the switching means 11 composed of such a three-way valve is controlled by a predetermined control means 12 composed of a microcomputer or the like.
[0014]
Next, an operation mode and the like for the present embodiment having such a configuration will be described. First, the damping action of engine idling vibration will be described. In this case, the switching means 11 is actuated by a command (signal) from the control means 12, and the working chamber 1 is held in the negative pressure suction state. As a result, the second diaphragm 2 is adsorbed on the bottom wall 111 of the working chamber 1. In such a state, when vibration is input to the liquid in the main chamber 6 via the insulator 8, the fluid pressure fluctuation generated in the liquid in the main chamber 6 does not act as a escape field. Therefore, the dynamic spring constant generally increases. However, in the present embodiment, the specifications (dimensions) of the first orifice 5 are such that the resonance frequency of the liquid in the first orifice 5 matches the input frequency of the engine idling vibration. Since it is set, the liquid in the first orifice 5 resonates with respect to the input of the vibration (engine idling vibration) of the specific frequency. As a result, the dynamic spring constant of the entire liquid-sealed vibration isolator is reduced as shown in FIG. 4 with respect to the vibration input of the specific frequency. That is, in FIG. 4, the bottom value of the dynamic spring constant can be obtained in a specific frequency range (engine idling vibration) of 15 Hz to 18 Hz. As a result, engine idling vibration can be effectively blocked or absorbed.
[0015]
On the other hand, with respect to damping of the engine shake, which is a vibration having a lower frequency than the engine idling vibration, the switching means 11 is switched to the atmospheric pressure introduction side in FIG. Then, the working chamber 1 is opened to the atmosphere, and the second diaphragm 2 that partitions the working chamber 1 and the main chamber 6 and the first diaphragm 41 that partitions the sub chamber 7 and the air chamber 4 are both used. Set free vibration. In such a state, when vibration relating to the engine shake is input into the main chamber 6, both the first diaphragm 41 and the second diaphragm 2 are free from fluid pressure fluctuations that occur in the liquid in the main chamber 6. Since both are in the vibration state, both 41 and 2 are bent and deformed. By the way, in this case, in the present embodiment, the second diaphragm 2 is set to have a higher rigidity value against the bending deformation than the first diaphragm 41, so that the liquid in the main chamber 6 is It flows preferentially toward the first orifice 5 side. That is, the liquid in the main chamber 6 flows toward the first orifice 5 with respect to the vibration input related to the engine shake, thereby obtaining a high damping force (shown by a thin broken line in FIG. 4). As a result, the engine shake is suppressed. As described above, in the present embodiment, the single orifice (first orifice) 5 exhibits a damping force generation function for engine shake vibration suppression, and the engine idling vibration has an orifice. The function of reducing the dynamic spring constant is exhibited by the resonance action of the inner liquid. That is, by using one orifice and making a difference in the flexural deformation rigidity of the diaphragm, a vibration control action of two vibrations such as an engine shake and an engine idling vibration is performed.
[0016]
Next, 2nd embodiment is described based on FIG.2 and FIG.5. The basic point of this is the same as that of the first embodiment. The difference is that a second orifice 32 and a third liquid chamber 33 connected to the second orifice 32 are provided between the second diaphragm 2 and the main chamber 6. That is, a third liquid chamber 33 having a predetermined volume is provided in contact with the second diaphragm 2 defining the working chamber 1, and a predetermined diameter and length are provided between the third liquid chamber 33 and the main chamber 6. The configuration is such that the second orifice 32 having a thickness is connected. Then, in the first orifice 5 and the second orifice 32 having such a configuration, each dimension (dimension) is set so that the liquid existing in each orifice is coupled to the vibration input of a specific frequency. ) Is set. Specifically, in FIG. 5, when the working chamber 1 is open to the atmosphere and the second diaphragm 2 is in a free vibration state, the second orifice 32 is about 25 Hz that is the frequency at the time of engine idling up. The dimensions (each dimension such as the diameter or length) of the second orifice 32 are set so that the vibration of the liquid inside and the vibration of the liquid inside the first orifice 5 are coupled to each other. As a result, the bottom value (reduction area) of the dynamic spring constant of the entire liquid-sealed vibration isolator can be obtained even in the vicinity of about 25 Hz (the thin solid line shown in FIG. 5).
[0017]
The operation mode of the embodiment having such a configuration will be described. First, absorption and blocking of engine idling vibration will be described. Of these, in order to absorb and cut off a normal frequency of 15 Hz to 18 Hz, the switching means 11 is operated based on a command (signal) from the control means 12 in FIG. Set to negative pressure state. Then, the second diaphragm 2 is held in a state of being adsorbed to the bottom wall 111 of the working chamber 1. In such a state, for the input of engine idling vibration having a frequency of 15 Hz to 18 Hz, the dynamic spring constant is caused by the resonance action of the liquid in the first orifice 5 as described in the first embodiment. Thus, a reduced area (bottom value) is obtained (thick solid line shown in FIG. 5). On the other hand, when the engine idling frequency increases due to the operation of the engine auxiliary equipment, that is, at the time of engine idling up, the switching means 11 in FIG. 2 is controlled based on a command (signal) from the control means 12. The operation chamber 1 is operated to open the atmosphere, and the second diaphragm 2 is held in a free vibration state. In this state, when vibration of a specific frequency is input to the liquid in the main chamber 6, the second diaphragm 2 freely vibrates due to the vibration action of the liquid via the second orifice 32. At this time, the dynamic spring constant is reduced in the specific frequency range by the resonance action of the liquid in the second orifice 32. At this time, the liquid in the first orifice 5 also exhibits some vibration action due to the free vibration of the first diaphragm 41. At this time, the vibration action of the liquid in the first orifice 5 and the resonance action of the liquid in the second orifice 32 are coupled to each other, and the liquid pressure fluctuation in the main chamber 6 is Will be absorbed more. As a result, the dynamic spring constant of the entire liquid-sealed vibration isolator is reduced. That is, as shown by the thin solid line in FIG. 5, a dynamic spring constant reduction region (bottom value) is obtained in the vicinity of 25 Hz. As a result, vibration is absorbed and cut off when the engine is idling up.
[0018]
The vibration of the engine shake is the same as that described in the first embodiment. That is, the second diaphragm 2 is brought into a free vibration state by bringing the working chamber 1 into an open air state. At this time, the first diaphragm 41 is also in a free vibration state. In such a state, the bending deformation rigidity of the second diaphragm 2 is set to be higher than the bending deformation rigidity of the first diaphragm 41, so that the liquid in the main chamber 6 flows into the first orifice 5. It will flow preferentially to the side. As a result, a predetermined damping force (peak value) is obtained by the flow of the liquid to the first orifice 5 (shown by a thin broken line in FIG. 5). This damping force causes the vibration control action of the engine shake.
[0019]
Next, a third embodiment of the present invention will be described with reference to FIG. The basic point of this is the same as that of the second embodiment. The difference is in the arrangement of the diaphragm. That is, as shown in FIG. 3, each diaphragm is provided with a first diaphragm 41 for partitioning between the air chamber 4 and the sub chamber 7 in a disc shape at the center, and a ring around the disc-shaped first diaphragm 41. The second diaphragm 2 is provided in a shape. Both the diaphragms 41 and 2 are integrally formed by a predetermined integral molding means. In addition, as described above, the diaphragms 41 and 2 are similar to those in the first embodiment and the second embodiment in that the second diaphragm 2 is more flexible and deformable than the first diaphragm 41. It is designed to have a high value.
[0020]
【The invention's effect】
According to the present invention, the first connecting member attached to the vibrating body, the second connecting member attached to the vehicle body side member, and the vibrating body between the first connecting member and the second connecting member. A rubber-like insulator that absorbs and blocks vibrations from the chamber, a chamber wall of which is formed by a portion of the insulator, in which liquid is sealed, and a first orifice in the chamber. And a sub-chamber in which a part of the chamber wall is partitioned by the first diaphragm, a partition member that partitions the main chamber and the sub-chamber, and an operation in which negative pressure or atmospheric pressure is appropriately introduced A liquid-filled vibration isolator comprising a second diaphragm that partitions between a chamber and the main chamber, and a second diaphragm that partitions the working chamber defines a first sub-chamber. More flexure than diaphragm Since to have a high value in the form rigid, at one orifice, called absorption and blocking of the damping and engine idling vibration of d Njinsheku, so it is possible to perform the damping action of the two kinds of vibration became.
[0021]
Further, a third liquid chamber is provided between the second diaphragm and the main chamber, and a second orifice through which a liquid flows is provided between the third liquid chamber and the main chamber, and the first orifice In the configuration in which the liquid existing in the inside and the liquid existing in the second orifice are coupled to the vibration input of a specific frequency, two locations in the engine idling frequency range are used. In addition to normal idling vibration, the dynamic spring constant can also be obtained in the frequency range when idling up due to the operation of auxiliary devices. Can be reduced. As a result, it is possible to cope with vibration isolation in two cases of normal idling vibration and vibration at idling up, and efficiently absorb and block both engine idling vibration and engine shake vibration. I can do it now.
[0022]
In the present invention, since the first diaphragm and the second diaphragm are integrally formed, the manufacturing cost for the two diaphragms can be reduced. became. That is, for example, the above two diaphragms can be molded together by an appropriate integral molding means, and the manufacturing cost of the entire liquid-sealed vibration isolator can be reduced, including parts management. I was able to plan.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an overall configuration of a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing the overall configuration of the second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing the overall configuration of the third embodiment of the present invention.
FIG. 4 is a diagram (graph) showing functional characteristics related to the first embodiment of the present invention.
FIG. 5 is a diagram (graph) showing functional characteristics of the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Working chamber 11 Switching means 111 Bottom wall 12 Control means 2 Second diaphragm 3 Partition plate 31 Communication path 32 Second orifice 33 Third liquid chamber 4 Air chamber 41 First diaphragm 5 First orifice 6 Main chamber 7 Sub chamber 8 Insulator 91 1st connection member 95 2nd connection member

Claims (4)

A first connecting member attached to the vibrating body, a second connecting member attached to the vehicle body side member, and a vibration between the first connecting member and the second connecting member between the first connecting member and the second connecting member. And a rubber-like insulator to be cut off, a main chamber in which a chamber wall is formed in a part of the insulator and in which a liquid is sealed, and connected to the main chamber via a first orifice A sub chamber in which a part of the chamber wall is defined by the first diaphragm, a partition member that partitions the main chamber and the sub chamber, a working chamber into which negative pressure or atmospheric pressure is appropriately introduced, and the main chamber In a liquid-filled vibration isolator comprising a second diaphragm that forms a partition between
Control means for introducing a negative pressure into the working chamber for engine idling vibration and for introducing an atmospheric pressure into the working chamber for an engine shake having a lower frequency than the engine idling vibration. With
The first orifice is set so that the liquid in the first orifice resonates with respect to the engine idling vibration in a state where negative pressure is introduced into the working chamber.
The liquid-filled vibration isolator characterized in that the second diaphragm that defines the working chamber has a higher value in flexural deformation rigidity than the first diaphragm that defines the sub chamber. .   2. The liquid filled type vibration damping device according to claim 1, wherein a third liquid chamber is provided between the second diaphragm and the main chamber, and a liquid flows between the third liquid chamber and the main chamber. A liquid-filled vibration isolator having two orifices. 3. The liquid filled vibration isolator according to claim 2, wherein the liquid existing in the first orifice and the liquid existing in the second orifice are vibrations having a higher frequency than normal engine idling vibrations. The liquid sealing is characterized in that it is set so as to be coupled to the vibration at the time, and the control means controls the atmospheric pressure to be introduced into the working chamber against the vibration at the time of engine idling up. Type vibration isolator.   4. The liquid-filled vibration isolator according to claim 1, wherein the first diaphragm and the second diaphragm are integrally formed.

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