JP4494988B2 - Liquid filled anti-vibration mount device - Google Patents

Description

  The present invention relates to a liquid-filled vibration-proof mount device in which vibration is damped by a flow resistance of a liquid flowing through a communication path (orifice path) between a plurality of liquid chambers formed inside, and in particular, a plurality of orifices. It belongs to the technical field of the structure of a switching type that obtains an effective anti-vibration action over a wide frequency band by switching the passage.

  Conventionally, an engine mount for automobiles is known as this type of vibration-proof mount device. The basic structure is that a rubber elastic body is interposed between the mounting member on the engine side and the support member on the vehicle body side, and the volume of the liquid chamber is changed between the two members so that the volume changes with the deformation of the rubber elastic body. In addition, the liquid chamber is partitioned into a pressure receiving chamber and an equilibrium chamber, and an orifice passage that communicates the pressure receiving chamber and the equilibrium chamber is provided. The liquid flows between the pressure receiving chamber and the equilibrium chamber via the orifice passage, so that vibration from the engine is absorbed and attenuated.

  By the way, since an automobile engine is generally used in a very wide driving state, an engine mount is required to have an anti-vibration effect for a plurality of types of vibration inputs having different frequencies and amplitudes. As described above, the frequency of vibration absorbed and damped by the flow of liquid in the orifice passage is largely determined by the cross-sectional area and length of the orifice passage. A sufficient anti-vibration effect cannot be obtained.

  In this regard, for example, in Patent Documents 1 to 3, a plurality of passages having different cross-sectional areas and lengths are provided so as to communicate with the pressure receiving chamber and the equilibrium chamber, respectively, and these passages are set according to the operating state of the engine. What is switched is disclosed. In other words, the liquid-filled mount disclosed in Patent Document 1 has a vibration at the time of engine start and a backlash at the time of shifting with respect to the partition plate that partitions the first liquid chamber (pressure receiving chamber) and the second liquid chamber (equilibrium chamber). An orifice passage with a large flow resistance tuned to a large amplitude vibration at a low frequency (about 5 to 15 Hz) such as vibration or shake is provided in a spiral shape, and a through hole with a smaller flow resistance than this is formed. The through hole is opened and closed by a valve portion formed integrally with the diaphragm of the equilibrium chamber.

  More specifically, for example, during idling of the engine, the valve portion is opened to open the through hole, and the liquid is circulated between the pressure receiving chamber and the equilibrium chamber through the through hole, thereby reducing the dynamic spring of the mount. Thus, vibration with a relatively low frequency (about 20 to 40 Hz) and small amplitude such as idle vibration is effectively absorbed. On the other hand, except during idle operation, the through hole is closed by the valve portion. When the vibration of the low frequency and large amplitude is input in this state, the through hole is closed, so that the liquid receives pressure through the orifice passage. The fluid flows between the chamber and the equilibrium chamber, and effective vibration damping is achieved by the flow resistance.

  Furthermore, in the thing of the said patent document 1, the inner peripheral side of the said valve part functions as a sub-diaphragm, and with a through-hole closed as mentioned above by this valve part, it is a minute amplitude from an engine. When high-frequency vibration is input, a change in the hydraulic pressure in the pressure receiving chamber due to this is absorbed by repetitive elastic deformation of the sub-diaphragm, which can reduce a booming noise in the vehicle interior of the automobile.

  Similarly, the liquid seal vibration isolator disclosed in each of Patent Documents 2 and 3 is tuned to engine idling vibration in a partition member that partitions the main liquid chamber (pressure receiving chamber) and the sub liquid chamber (equilibrium chamber). An idle orifice passage (second orifice passage) and a damping orifice passage (second orifice passage) tuned to a vibration having a lower frequency and a larger amplitude are provided, and an opening on the side of the secondary liquid chamber of the idle orifice passage is provided. The auxiliary liquid chamber is opened and closed by a thick seat formed at the center of the diaphragm that partitions the sub liquid chamber.

In particular, in the one described in Patent Document 2, the seat portion is formed thick, and both the upper and lower surfaces thereof are recessed to form a thin portion in the center, and the internal pressure fluctuation of the main liquid chamber is caused by the deformation of the thin portion. On the other hand, in the device described in Patent Document 2, the outer peripheral portion of the partition member is floatingly supported via an elastic member, and the movement of the partition member as a whole absorbs fluctuations in the internal pressure of the main liquid chamber. Like to do. By absorbing the internal pressure fluctuation in the main liquid chamber in this way, it is possible to prevent the generation of abnormal noise due to the internal pressure fluctuation in the main liquid chamber when the engine is started.
JP-A-8-277879 JP 2003-4086 A Japanese Patent Laid-Open No. 2003-4091

  However, the conventional anti-vibration mount device as described above is quite effective for relatively low-frequency vibrations such as engine shake and idle vibration, but it is relatively high-frequency vibrations that cause a booming noise. It was not very effective. That is, the engine mount of the former conventional example (Patent Document 1) closes the through hole by a part of the diaphragm that partitions the equilibrium chamber, and uses that part as an elastic film for absorbing the fluid pressure fluctuation due to the high frequency vibration. However, since the surface opposite to the through hole is in contact with the atmosphere, this elastic membrane is likely to be excessively deformed when a large fluid pressure fluctuation of the pressure receiving chamber due to vibration input of low frequency and large amplitude acts. While the durability is significantly reduced, there is a risk of premature breakage.

  Therefore, it is assumed that the elastic membrane is relatively thick and soft and capable of large elastic deformation in order to maintain durability even when subjected to large fluid pressure fluctuations. Since the natural frequency of such an elastic membrane does not increase so much, even if it is possible to reduce the vibration corresponding to the so-called low and medium speed booming noise up to about 100 Hz in terms of automobile interior noise, The vibration in the high frequency range cannot be effectively reduced.

  In addition, if the elastic film is greatly deformed when low-frequency large-amplitude vibration is input as described above, the fluid pressure fluctuation in the pressure receiving chamber is absorbed thereby, and accordingly, the amount of liquid flow in the orifice passage Decreases, and the vibration absorption and damping effect due to the flow resistance is adversely affected.

  On the other hand, the latter conventional examples (Patent Documents 2 and 3) do not disclose any specific structure for absorbing or attenuating high-frequency vibrations from the engine. In general, it is known to arrange a so-called high-frequency device in the pressure receiving chamber in order to absorb high-frequency vibrations. This high-frequency device is composed of an umbrella member arranged in the pressure receiving chamber and a rubber elastic body surrounding the umbrella member. The gap between the inner surface of the wall is regarded as an orifice passage, and the size of this gap inherently includes a large error due to the size of the rubber elastic body and the assembly error of the umbrella member. It includes the drawback that tuning to the frequency range is very difficult.

  The present invention has been made in view of such various points, and an object of the present invention is to provide a liquid-filled vibration-proof mount device suitable for an engine mount of an automobile, in a vibration, shake, idle vibration at the time of shifting. While absorbing and attenuating relatively low-frequency vibrations as in the past, it is also possible to effectively absorb and attenuate high-frequency vibrations that cause humming noise, etc. to a higher frequency range than before. There is.

In order to achieve the above object, in the present invention, a lid member made of an elastic film is disposed in the equilibrium chamber of the vibration-proof mount device, thereby opening and closing the opening on the equilibrium chamber side of the orifice passage, Then, even when the opening portion is closed, both the surfaces of the lid member are in contact with the liquid, and the liquid that forms a sub liquid chamber in the equilibrium chamber integrally with the lid member A chamber forming member is provided, and the liquid chamber forming member is formed with a communication path that communicates the inside of the sub liquid chamber with an external equilibrium chamber .

Specifically, the invention of claim 1 is characterized in that the mounting member attached to the supported body, the supporting member that supports the mounting member via the rubber elastic body, and the volume change with the deformation of the rubber elastic body. A liquid-filled vibration-proofing device comprising: a liquid chamber formed between the two members; a partition member that divides the liquid chamber into a pressure receiving chamber and an equilibrium chamber; and a first orifice passage that communicates the pressure receiving chamber and the equilibrium chamber. Targeting the mount device .

Its to the with the partition member through providing the second orifice passage communicating the pressure receiving chamber and the equilibrium chamber, said equilibrium chamber, capable of opening and closing the opening of the equilibrium chamber side of the second orifice passage A lid member made of an elastic film and a liquid chamber forming member that forms a sub liquid chamber in the equilibrium chamber integrally with the lid member are disposed, and the lid member is opposed to the opening of the second orifice passage communicating passage opposite surface to the surface to have the while placed in a state in contact with the liquid faces the auxiliary liquid chamber, the liquid chamber forming member, which communicates with the internal external equilibrium chamber of the auxiliary fluid chamber Formed .

  According to the above configuration, first, when the opening on the equilibrium chamber side of the second orifice passage is closed by the lid member, a vibration having a low frequency and a large amplitude is input to the vibration isolation mount device, and the mounting member and the support member When the relative displacement is relatively large, the volume of the pressure receiving chamber changes with the deformation of the rubber elastic body, and the liquid flows through the first orifice passage between the equilibrium chamber and the liquid due to the fluctuation of the hydraulic pressure. Vibration is absorbed and damped by the flow resistance.

At that time, the fluid pressure fluctuation in the pressure receiving chamber also acts on the lid member via the second orifice passage, but the surface of the lid member opposite to the surface facing the opening of the second orifice passage is , because it is arranged in a state in contact with the liquid faces the auxiliary liquid chamber, even when a large liquid pressure fluctuations due to vibrations of low frequency, large amplitude acts as described above, the liquid of the secondary liquid chamber becomes buffer Thus, the lid member is not excessively deformed. Therefore, it is possible to prevent the durability from being deteriorated and the early breakage due to the excessive deformation of the lid member made of the elastic film, and the deformation does not have a great adverse effect on the vibration absorption and damping action by the first orifice passage.

In addition, when the volume of the pressure receiving chamber changes minutely in a short cycle due to the input of high frequency vibration in the state where the opening on the equilibrium chamber side of the second orifice passage is closed by the lid member as described above, the hydraulic pressure fluctuation due to this changes. In response to the elastic deformation of the lid member, the volume of the secondary liquid chamber changes minutely, and a small amount of liquid flows through the communication path to the equilibrium chamber, and vibrates due to the flow resistance of the liquid. Will be absorbed and attenuated.

That is, that both sides of the lid member as described above is placed in contact with the liquid body, because it can suppress the deformation, the spring characteristics of the cover member can be set relatively freely, for example, conventional Even if it is thin, the durability is not lowered and premature breakage is not caused. Therefore, after tuning the spring characteristics of the lid member to a higher frequency range than before , the communication path between the auxiliary liquid chamber and the equilibrium chamber is considered as the third orifice path, and for example, the interior noise of an automobile In other words, by tuning to a frequency range corresponding to a so-called high-speed booming sound of about 300 to 500 Hz, such high-frequency vibrations can be absorbed and attenuated more effectively.

  On the other hand, when the second orifice passage is open, liquid flows between the pressure receiving chamber and the equilibrium chamber through the second orifice passage. If it is tuned to a frequency range intermediate between the low-frequency large-amplitude vibration that is effectively absorbed and damped by the first orifice passage and the high-frequency vibration that is absorbed by the elastic deformation of the lid member as described above, The vibration in the frequency range can be effectively absorbed and attenuated.

That is, according to the vibration-proof mount device having the above-described structure, vibrations of relatively low frequency can be absorbed and attenuated by the flow of liquid in the first and second orifice passages, and the elastic deformation of the lid member made of the elastic film and the third Due to the flow of the liquid in the communication path, which is the orifice, it is possible to effectively absorb vibrations of relatively high frequency up to a higher frequency range than before .

As a more specific configuration of such an anti-vibration mount device, it is preferable that a cylindrical portion having a bottom extending in the equilibrium chamber toward the partition member is integrally formed on a diaphragm that partitions the equilibrium chamber, and this cylindrical shape is formed. The secondary liquid chamber is partitioned by closing the tip opening of the part with a lid member, a communication path is formed so as to penetrate the peripheral wall part of the cylindrical part, and further, the bottom part or the peripheral wall part of the cylindrical part is formed. The reinforcing member is embedded in at least a part (the invention of claim 2 ).

  In this configuration, the cylindrical portion (liquid chamber forming member) that partitions the auxiliary liquid chamber in the equilibrium chamber together with the lid member is integrally formed in the diaphragm, thereby reducing costs and, as a result, formed by an elastic body. When the volume of the sub liquid chamber changes minutely by reinforcing the peripheral wall and bottom of the cylindrical portion with a reinforcing member and suppressing deformation due to hydraulic pressure, the flow of liquid in the communication passage between the sub chamber and the equilibrium chamber Can be ensured stably, and the vibration absorption and damping action due to the flow resistance can be obtained more reliably.

Further, when the anti-vibration mount device having the above-described configuration is used as an engine mount of an automobile, that is, when the supported body is an automobile engine, it is preferable that the anti-vibration mount apparatus is opposite to the cylindrical portion of the diaphragm of the anti-vibration mount apparatus On the side, a hook-like member made of an elastic body and bulging toward the diaphragm is disposed in a pre-compressed state, and the tubular portion is pressed and urged toward the partition member by its restoring force. A negative pressure chamber into which intake negative pressure of the engine is guided is defined on the inner peripheral side of the member (invention of claim 3 ).

  In this way, when the intake negative pressure is high, such as during idling of the engine, the large negative pressure is guided to the negative pressure chamber, so that the saddle-shaped member contracts and the cylindrical portion of the diaphragm moves away from the partition member. Moving, the second orifice passage is opened. As a result, as described above, idle vibration with low frequency and relatively small amplitude is effectively absorbed and attenuated.

  On the other hand, since the intake negative pressure of the engine is not so large except during idling, the tubular portion of the diaphragm is pressed and urged toward the partition member by the restoring force of the arm member in the precompressed state. The second orifice passage is closed by the lid member at the tip of the cylindrical portion. This effectively absorbs and attenuates low-frequency large-amplitude vibrations such as vibrations during shakes and shakes as described above, and also effectively absorbs high-frequency vibrations. The frequency is effectively reduced from the high range to the high range.

In addition, in the anti-vibration mount device having the above-described configuration, it is preferable that the diaphragm and the hook-shaped elastic body are respectively formed with engaging portions so as to engage with each other (invention of claim 4 ). By preventing the positional deviation between the two, the action of the above-described invention can be obtained more reliably.

  As described above, according to the liquid-filled vibration-proof mount device of the present invention, the opening on the equilibrium chamber side of the orifice passage that penetrates the partition member between the pressure receiving chamber and the equilibrium chamber is formed in the equilibrium chamber. When the opening is closed, both sides of the lid member come into contact with the liquid when the opening is closed. Even when large-amplitude vibration is input at a relatively low frequency, such as vibration at the time, shake or idle vibration, the lid member is not excessively deformed, and such low-frequency large-amplitude vibration is effective. The high-frequency vibration from the engine can be effectively absorbed to a higher frequency range than before by the elastic deformation of the lid member. Forest sound also can made sufficiently reduced.

In particular, by a liquid chamber forming member and the lid member which is disposed in the equilibrium chamber, said equilibrium auxiliary liquid chamber is partitioned and formed in the room, the communicating passage in communication with the sub-liquid chamber outside the equilibrium chamber third orifice By using it as a passage, it is possible to more effectively absorb and attenuate high-frequency vibrations that cause so-called high-speed booming noise.

According to the invention of claim 2 , the liquid chamber forming member is integrally formed in the diaphragm as a tubular portion, and the tubular portion is appropriately reinforced while reducing the cost. The effect of the invention of 2 can be obtained more reliably.

Furthermore, according to the third aspect of the present invention, it is possible to appropriately switch the characteristics of the vibration-proof mount device during idle operation and other times by using the intake negative pressure of the engine.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  FIG. 1 shows an embodiment in which a liquid-filled vibration-proof mount device of the present invention is applied to an automobile engine mount A. The engine mount A is interposed between an automobile power plant (not shown) and a vehicle body, While supporting the load of the power plant, the vibration from the power plant is absorbed or attenuated to suppress vibration transmission to the vehicle body.

  The engine mount A of this embodiment has a substantially cylindrical metal attachment member 1 attached to a power plant via a bracket or the like (not shown), and a cylindrical shape that supports this from the lower outer peripheral side via a rubber elastic body 2. A metal casing 3 (support member) is provided, and is fixed to the vehicle body frame by legs 33, 33,... Welded to the lower outer periphery of the casing 3.

  The attachment member 1 has a flange portion 11 projecting outward at an intermediate portion in the vertical direction, and has a tapered shape in which the lower side is recessed downward. On the other hand, a bracket on the power plant side is attached to the upper part of the attachment member 1, and a bolt hole 12 into which a fastening bolt for that purpose is screwed opens at the upper end surface. The collar portion 11 is covered with stopper rubbers 13 and 14 for regulating excessive displacement of the power plant in cooperation with a stopper fitting 8 and the like which will be described later.

  The rubber elastic body 2 is vulcanized and bonded at its upper portion to cover the lower tapered portion of the mounting member 1, and a thick-walled umbrella-shaped portion 21 extending obliquely downward while expanding radially therefrom. The cylindrical portion 22 includes a cylindrical portion 22 extending continuously downward from the lower end of the umbrella-shaped portion 21, and the cylindrical portion 22 is fixed to the inner periphery of the casing 3. That is, the casing 3 has a double structure comprising an inner cylinder member 31 on the inner circumference side and an outer cylinder member 32 on the outer circumference side, and the inner cylinder member 31 is embedded in the cylindrical portion 22 of the rubber elastic body 2. The cylindrical portion 22 is fitted on the inner peripheral side of the outer cylinder member 32.

  The cylindrical portion 22 of the rubber elastic body 2 has a lower inner diameter larger than that of the upper side, and an annular step portion 23 is formed at the boundary between them. Then, as the stepped portion 23, the resin-made partition member 4 is pushed into the inner periphery of the cylindrical portion 22 of the rubber elastic body 2 from below and accommodated, and further, the partition member 4 is covered from below, A rubber diaphragm 5 is provided. An annular metal reinforcing plate is embedded in the outer peripheral portion of the diaphragm 5, and the reinforced portion is caulked from below by a flange formed inwardly at the lower end edge of the inner cylindrical member 31 of the casing 3. And fixed.

  Then, the lower end opening of the rubber elastic body 2 is liquid-tightly closed by the diaphragm 5, and a cavity is formed inside. The cavity is filled with a liquid such as ethylene glycol, and the rubber elasticity It is a liquid chamber F for absorbing and mitigating vibrations of the power plant input to the body 2. The interior of the liquid chamber F is partitioned vertically by the partition member 4, and the upper side thereof is a pressure receiving chamber f1 in which the volume changes due to deformation of the rubber elastic body 2 due to vibration input and the fluid pressure fluctuates. In addition, the lower side of the liquid chamber F is expanded or reduced in volume by the deformation of the diaphragm 5, and becomes an equilibrium chamber f2 that absorbs the volume variation of the pressure receiving chamber f1.

  While the diaphragm 5 is fixed to the lower end portion of the inner cylinder member 31 of the casing 3 as described above, the outer cylinder member 32 of the casing 3 extends further downward so that the opening at the lower end is closed. A flat hollow truncated cone-shaped rubber bowl member 6 and a resin disk member 7 are attached in this order. That is, the bowl-like member 6 is disposed in a state where the bowl is faced down on the lower side of the diaphragm 5, and the lower opening thereof is closed by the disk member 7.

  More specifically, the bowl-shaped member 6 has a disk-like ceiling portion 61 in contact with the upper diaphragm 5, and a peripheral wall portion 62 extending obliquely outwardly from the outer peripheral end of the ceiling portion 61 downward. At the lower end, that is, at the outer peripheral end of the bowl-shaped member 6, the outer peripheral end of the disk member 7 is fixed to the metal bracket 34 at the lower end of the casing 3. The bracket 34 has a cylindrical shape formed by drawing a steel pipe, for example, and the upper portion thereof is press-fitted into the casing outer cylinder member 32.

  The bracket 34 has a lower portion having a diameter larger than that of the upper portion, and an annular step portion is formed at the boundary between the brackets 34. The disc members 7 are sequentially accommodated from below, and the outer peripheral end portion of the bowl-like member 6 is bent downward and sandwiches the outer peripheral end portion of the disc member 7 so that the disc member 7 faces inward toward the lower end edge of the bracket 34. It is caulked from below by a flange formed on the surface.

  On the other hand, a stopper fitting 8 having a cylindrical shape slightly smaller than the outer cylinder member 32 is attached to the upper end portion of the casing 3. A flange projecting outward is formed at the peripheral edge of the opening at the lower end of the stopper fitting 8, and this flange is placed on the upper end of the cylindrical portion 22 of the rubber elastic body 2, and is placed on the upper end edge of the outer cylinder member 32. It is caulked from above by a flange formed inward.

  An annular wall portion 81 extending inwardly in a substantially horizontal direction so as to surround the attachment member 1 is formed at the opening peripheral edge portion of the upper end of the stopper fitting 8, and the lower surface of the annular wall portion 81 is the attachment member 1. By abutting against the stopper rubber 13 on the upper surface of the flange portion 11, the upward movement of the mounting member 1 is restricted. An annular stopper rubber 15 is vulcanized and bonded to the upper surface of the annular wall 81 so as to abut on a power plant side mounting bracket (not shown).

  1 shows a state where a static load of the power plant is not applied to the engine mount A, and the stopper rubber 13 on the upper surface of the flange portion 11 of the mounting member 1 is the lower surface of the annular wall portion 81 of the stopper fitting 8. In the 1G state where the engine mount A is attached to the car body of the automobile to support the power plant and the static load is applied, the rubber elastic body 2 is bent and the mounting member 1 is moved downward. Due to the displacement, a predetermined gap is formed between the stopper rubber 13 and the stopper fitting 8.

(Detailed structure of liquid chamber F)
Next, in the engine mount A, the structure of the liquid chamber F for absorbing and damping the vibration from the power plant by the flow of the liquid will be described in detail. In this embodiment, as described above, the partition member 4 that partitions the liquid chamber F into the pressure receiving chamber f1 and the equilibrium chamber f2 is formed in a disk shape having a large thickness as shown in FIG. It comprises a disc-shaped partition plate portion 41 for partitioning f1 and f2, and an annular passage forming portion 42 for forming an orifice passage in the lower outer peripheral side portion as follows.

  That is, an opening groove 43 extending in the circumferential direction is provided on the outer periphery of the passage forming portion 42, and the cylindrical portion 22 is accommodated in the cylindrical portion 22 of the rubber elastic body 2 as shown in FIG. An annular passage P <b> 1 (hereinafter referred to as a first orifice) is formed by the inner peripheral surface and the opening groove 43. One end of the first orifice passage P1 communicates with the pressure receiving chamber f1 through an opening 41a opened on the upper surface of the partition plate portion 41, while the other end is not shown in the drawing of the passage forming portion 42. It opens to the inner peripheral surface and faces the equilibrium chamber f2.

  The dimension (cross-sectional area and length) of the first orifice passage P1 is lower in frequency (for example, 5 to 5) than idle vibration such as vibration at engine start, rattling vibration generated at the time of shifting, or shake during running. 15 Hz), and is tuned according to the vibration having a large amplitude, and the liquid column resonance is generated by the vibration having the low frequency and the large amplitude.

  Further, a cylindrical projecting portion 44 is formed so as to extend from a substantially central portion of the upper surface of the partition plate portion 41 of the partition member 4 toward the upper pressure receiving chamber f1, and the passage in the projecting portion 44 is divided into partitions. The lower end opening of the plate portion 41 faces the equilibrium chamber f2. The passage forms a second orifice passage P2 that penetrates the partition plate portion 41 and communicates with the pressure receiving chamber f1 and the equilibrium chamber f2. The second orifice passage P2 is tuned to idle vibration of the engine. The liquid column resonance is caused by the input of vibration with a relatively low frequency (for example, 20 to 40 Hz) and not so large amplitude.

  Then, the bottomed cylindrical shape projecting upward is formed in the central portion of the lower diaphragm 5 so as to face the lower end opening portion of the second orifice passage P2 that opens to the lower surface of the partition plate portion 41. A portion 51 is formed, and a cap 9 made of a rubber elastic body is externally provided so as to cover substantially the whole from the distal end side of the cylindrical portion 51. The cap 9 and the cylindrical portion 51 of the diaphragm 5 move integrally up and down, and the ceiling 91 of the cap 9 opens and closes the lower end opening (the opening on the equilibrium chamber f2 side) of the second orifice passage P2. It is supposed to be.

  That is, the cap 9 is formed in a bottomed cylindrical shape whose inner diameter is slightly smaller than the outer diameter of the cylindrical portion 51 of the diaphragm 5, and is inverted so that the bottom portion becomes the ceiling portion 91. The outer surface is covered with the shape portion 51. An enlarged diameter portion is provided on the distal end side of the outer periphery of the cylindrical portion 51, while an enlarged diameter portion of a size corresponding to the inner circumference of the cap 9 is provided, and these are fitted. By doing so, the cap 9 and the cylindrical part 51 are assembled | attached integrally.

  Normally, as shown in FIG. 1, the lower end opening of the second orifice passage P <b> 2 is closed by the ceiling portion 91 of the cap 9, and the cap 9 moves downward together with the cylindrical portion 51 as described later. (See FIG. 3), the opening is opened. In other words, the ceiling portion 91 of the cap 9 is a lid member made of an elastic film disposed in the equilibrium chamber f2 so that the opening of the second orifice passage P2 on the equilibrium chamber f2 side can be opened and closed (hereinafter referred to as the cap 9). Of the ceiling part is referred to as the lid part 91). In the example shown in the figure, an annular rib is provided so as to surround the periphery of the opening of the second orifice passage P2, but this rib may not be provided.

  In the state where the cap 9 is externally mounted on the cylindrical portion 51 of the diaphragm 5 as described above, the lid portion 91 of the cap 9 is closed at the tip opening of the cylindrical portion 51, and a hollow portion is formed inside them. In addition, rectangular cutouts 92 and 52 are formed in the respective peripheral wall portions of the cap 9 and the cylindrical portion 51 that are overlapped with each other, so that the hollow portion communicates with the external equilibrium chamber f2. It has become so. Thus, the cap 9 and the cylindrical portion 51 of the diaphragm 5 are integrated to form a sub liquid chamber f3 in the equilibrium chamber f1, and the lower surface of the lid portion 91 of the cap 9 is formed in the sub liquid chamber f3. In contact with the liquid.

  Further, as described above, the rectangular cross-section passage that connects the auxiliary liquid chamber f3 to the external equilibrium chamber f2 functions as a third orifice passage P3 for absorbing and damping high-frequency vibrations from the engine. Become. In other words, the dimensions (cross-sectional area and length) of the third orifice passage P3 are tuned in accordance with minute vibrations in a high-frequency region (for example, 300 to 500 Hz) that generate a so-called high-speed booming noise in the vehicle cabin. In addition, such high-frequency minute vibrations can be effectively absorbed and attenuated by the flow resistance of the liquid.

  Further, in order to effectively function the passage between the auxiliary liquid chamber f3 and the external equilibrium chamber f2 as the third orifice passage P3, the cylindrical portion excluding the formation site of the third orifice passage P3 is used. A metal reinforcing plate 53 (shown only in FIG. 1) is embedded from the peripheral wall portion 51 to the bottom portion so as to surround the sub liquid chamber f3. In this way, by increasing the rigidity of the peripheral wall portion and the bottom portion of the cylindrical portion 51 surrounding the secondary liquid chamber f3, the lid portion 91 of the cap 9 is elastically deformed in accordance with the input of the high frequency vibration as described above, and the volume of the secondary liquid chamber f3. Can be stably ensured in the third orifice passage P3.

  On the other hand, the ceiling portion 61 of the bowl-shaped member 6 is in contact with the lower surface of the central portion of the diaphragm 5 on the side opposite to the cylindrical portion 51 as described above. A convex portion 63 protruding upward from the portion is formed, and this is engaged with a concave portion 54 formed at the center of the lower surface of the diaphragm 5. An enlarged diameter portion is provided at the tip of the convex portion 63, and an enlarged diameter portion having a corresponding size is also provided on the inner side of the concave portion 54. It comes to match.

  In addition, a metal reinforcing plate is embedded in the ceiling portion 61 of the bowl-shaped member 6 so as to restrict its elastic deformation, and the circumferential wall section 62 of the bowl-shaped member 6 expands in the radial direction. The ceiling 61 can be displaced relatively easily in the vertical direction by being squeezed. As shown in FIG. 1, the saddle-shaped member 6 is sandwiched between the upper diaphragm 5 and the lower disk member 7 in a state of being disposed adjacent to the lower side of the diaphragm 5, and is preliminarily moved in the vertical direction. The diaphragm 5 is compressed, and the diaphragm 5 is pressed and urged toward the partition member 4 by its own restoring force (elasticity of rubber).

  The disk member 7 that closes the lower opening of the bowl-shaped member 6 is manufactured by, for example, injection molding, and the upper surface thereof has an annular shape at a portion corresponding to the outer periphery of the ceiling portion of the bowl-shaped member 6 facing upward. And a circular boss portion 72 is provided on the inner peripheral side of the rib 71. The boss portion 72 functions as a stopper for receiving the boss portion 72 when the ceiling portion of the bowl-shaped member 6 is displaced downward as described below.

  A cylindrical portion 73 is formed in the central portion of the disc member 7 so as to extend downward on the back side of the boss portion 72, and a passage in the cylindrical portion 73 is a substantially central portion of the disc member 7. Is opened on the upper surface of the boss portion 72. The space surrounded by the flange-like member 6 and the disk member 7 is defined by a passage in a vacuum hose (shown by an imaginary line) connected to the lower end side of the cylindrical portion 72. It is communicated to. In other words, a negative pressure chamber V into which the intake negative pressure of the engine is guided is defined by the disc member 7 on the inner peripheral side of the bowl-shaped member 6.

  Thus, when the intake negative pressure is high, such as during idling of the engine, this acts on the negative pressure chamber V via the vacuum hose, so that the hook-like member 6 resists its own elastic force. Shrink. That is, the flange-shaped member 6 is elastically deformed so that the entire peripheral wall portion 62 expands in the radial direction, and the ceiling portion 61 is displaced downward, and the tubular portion 51 of the diaphragm 5 engaged therewith. Is displaced downward. As a result, as shown in FIG. 3, the cylindrical portion 51 of the diaphragm 5 and the cap 9 sheathed at the tip thereof move downward, and the lid portion 91 of the cap 9 becomes the opening portion of the second orifice passage P2. Will be released.

(Function and effect)
Next, in the engine mount A configured as described above, the action of the liquid chamber F that absorbs and attenuates vibrations from the engine will be described separately for the idle operation and other states.

  First, when the engine is in an operating state other than idling and the intake negative pressure is not so large, as shown in FIG. 1, the cylindrical portion 51 of the diaphragm 5 receives a pressing force from the flange-like member 6 and receives the partition member 4. The lid portion 91 of the cap 9 located at the tip of the cylindrical portion 51 covers the opening on the side of the equilibrium chamber f2 of the second orifice passage P2 formed in the partition member 4. It comes to close. When a vibration with a low frequency and a large amplitude such as a shaking vibration at the time of shifting or a running shake is input to the engine mount A and the mounting member 1 and the casing 3 are relatively displaced relatively, a rubber elastic body With the deformation of 2, the volume of the pressure receiving chamber f1 changes relatively greatly, and due to the fluctuation of the hydraulic pressure caused thereby, the liquid flows through the first orifice passage P1 between the pressure receiving chamber f1 and the equilibrium chamber f2.

  Here, as described above, the first orifice passage P1 is tuned in accordance with the vibration or shake at the time of the shift, and generates a liquid column resonance corresponding to those vibration inputs. Therefore, as shown in FIG. 4 as an example, the engine mount A has a low dynamic spring constant Kd with a peak around 10 Hz in the example shown in the figure for a vibration input having a relatively large amplitude of about ± 0.5 mm, for example. In addition, vibration characteristics having a large loss coefficient tan δ are exhibited, whereby vibrations with relatively large amplitudes such as vibrations during shifting and shakes are well absorbed and damped, thereby improving riding comfort.

  At this time, the hydraulic pressure fluctuation in the pressure receiving chamber f1 also acts on the lid portion 91 of the cap 9 that closes the second orifice passage P2, and this lid portion 91 is in the equilibrium chamber. Since the liquid is disposed in f2 and both surfaces thereof are in contact with the liquid, the liquid on the equilibrium chamber f2 side is buffered even if a large fluid pressure fluctuation due to vibration input with a low frequency and large amplitude acts as described above. Thus, the lid 91 is not excessively deformed. Therefore, there is no deterioration in the durability of the cap 9 due to excessive deformation of the lid portion 91 made of an elastic film and early breakage, and the deformation of the lid portion 91 absorbs vibration by the first orifice passage P1, There is no significant adverse effect on the damping effect.

  Further, as described above, in a state where the opening portion on the equilibrium chamber f2 side of the second orifice passage P2 is closed by the lid portion 91 of the cap 9, for example, high-frequency minute vibrations caused by high-speed operation of the engine or the like are input. When the volume of the pressure receiving chamber f1 changes minutely in a very short cycle, this minute volume change, that is, high-frequency vibration is effectively absorbed by the minute elastic deformation of the lid portion 91 made of an elastic film.

  Here, in this embodiment, the lid portion 91 of the cap 9 is arranged so that both surfaces thereof are in contact with the liquid as described above, so that the deformation can be suppressed and the durability can be prevented from being lowered or early damaged. The spring characteristic of the lid portion 91 can be set relatively freely. Therefore, by tuning the spring characteristics of the lid member 91 to a higher frequency range than before, it is possible to absorb relatively high-frequency vibrations that cause a booming noise in the vehicle interior to a higher frequency range.

  Furthermore, in this embodiment, the cap 9 is put on the cylindrical portion 51 of the diaphragm 5 to form a sub liquid chamber f3 therein, and the sub liquid chamber f3 communicates with the external equilibrium chamber f2. A third orifice passage P3 is provided so that high-frequency vibrations can be absorbed and attenuated more effectively. That is, when the second orifice passage P2 is closed by the lid portion 91 of the cap 9 as described above and the volume of the pressure receiving chamber f1 changes minutely in a short cycle due to the input of high-frequency vibration, the fluid pressure fluctuation due to this changes. In response, the cover 91 is elastically deformed to change the volume of the auxiliary liquid chamber f3, and a small amount of liquid flows through the third orifice passage P3 between the equilibrium chamber f2 and vibration is absorbed by the flow resistance. It becomes attenuated.

  FIG. 5 shows that the dynamic spring constant Kd of the engine mount A with respect to a vibration input with a minute amplitude of, for example, about ± 0.05 mm is compared with the conventional one (for example, a configuration similar to that of Patent Document 1: indicated by a virtual line). It is an image figure which shows a mode that it is low. In this embodiment, as described above, the spring characteristic of the lid portion 91 is tuned in accordance with a higher frequency range than in the prior art, so that the dynamic spring is lowered in a high frequency range of about 80 Hz or more, and the third orifice In a specific frequency range (about 400 to 600 Hz in the example in the figure) that causes liquid resonance in the passage P3, the dynamic spring is significantly reduced. By setting the bottom of this dynamic spring to the optimal range experimentally according to the vibration characteristics of the engine, it is possible to absorb high-frequency vibrations very effectively as intended. Can be effectively reduced.

  On the other hand, when the engine is idling, the intake negative pressure increases, and when this acts on the negative pressure chamber V in the saddle member 6 via the vacuum hose, the saddle member 6 contracts as shown in FIG. The ceiling portion 61 is displaced downward, so that the cylindrical portion 51 of the diaphragm 5 moves downward integrally with the cap 9. Thereby, the cover part 91 of the cap 9 located at the tip of the cylindrical part 51 opens the opening part on the equilibrium chamber f2 side of the second orifice passage P2.

  As described above, when the idling vibration of the engine is input in a state where the pressure receiving chamber f1 and the equilibrium chamber f2 are communicated with each other by the second orifice passage P2, the volume and the hydraulic pressure of the pressure receiving chamber f1 fluctuate in a predetermined cycle. Due to the fluctuation of the fluid pressure, the fluid flows between the equilibrium chamber f2 via the second orifice passage P1, and thereby the idle vibration is effectively damped.

  That is, the second orifice passage P2 is tuned so as to generate liquid column resonance in response to engine idling vibration. Thus, as shown in FIG. 6, for example, the amplitude is ± 0.1 mm. For such idle vibration input, the engine mount A has a vibration damping characteristic having a low dynamic spring constant Kd with a peak around 30 Hz and a large loss coefficient tanδ. From this, it can be seen that the idle vibration is well absorbed and damped.

  Therefore, according to the engine mount A (liquid-filled vibration-proof mount device) according to this embodiment, for example, vibration at the start of the engine, rattling vibration at the time of shifting, vibration with low frequency and large amplitude such as a shake during traveling, It is possible to improve the ride comfort of the car by absorbing and attenuating both idle vibrations with a slightly higher frequency and smaller amplitude as before, as well as high-frequency vibrations generated by the engine. Can be effectively absorbed up to a higher frequency range than before, so that the muffled noise in the vehicle compartment can be sufficiently reduced to not only the so-called medium-low muffled noise but also the high-speed muffled noise.

(Other embodiments)
The configuration of the present invention is not limited to the above-described embodiment, but includes other various aspects. That is, in the above-described embodiment, for example, the flange member 6 and the disk member 7 are caulked and fixed to the bracket 34 and then press-fitted into the lower end portion of the outer cylinder member 31 of the casing 3, but this is not limitative. For example, as shown in FIG. 7, the bracket 34 is press-fitted into the lower end portion of the outer cylinder member 31, and the flange-like member 6 and the disc are interposed between the lower end portion of the outer cylinder member 31 and the flange at the lower end of the bracket 34. The member 7 may be sandwiched and fixed.

  Moreover, in the said embodiment, in order to make the 3rd orifice channel | path P3 function effectively, although the metal reinforcement board 53 is embed | buried from the surrounding wall part of the cylindrical part 51 of the diaphragm 5 to the bottom part, it is like this. For example, as shown in FIG. 7, only the peripheral wall portion may be used as the reinforcing portion, or only the bottom portion may be reinforced although not shown.

  Furthermore, in the above-described embodiment, the cap 9 is sheathed so as to cover substantially the entire peripheral wall portion of the tubular portion 51 of the diaphragm 5, thereby making it easy to ensure the length of the third orifice passage P3. However, the present invention is not limited to this. For example, as shown in FIG. 8, a cap 9 having a short length can be used so as to cover only the tip end side of the protruding portion 51 excluding the portion that becomes the third orifice passage P3. .

In the above embodiment, the protrusion 51 is integrally formed with the diaphragm 5 as a liquid chamber forming member for partitioning and forming the sub liquid chamber F3 in the equilibrium chamber f2, thereby reducing the cost. However, the present invention is not limited to this, and the liquid chamber forming member may be formed separately from the diaphragm 5 using, for example, a resin or the like and disposed in the equilibrium chamber f2 .

  In addition, in the above-described embodiment, the vibration-proof mount device of the present invention is applied to the vertical engine mount A that receives a compressive load from above, but is not limited to this, for example, pulling downward Of course, the present invention can be applied to a horizontally mounted engine mount that receives a load, and it is needless to say that the present invention can also be applied to various anti-vibration mount devices other than the engine mount.

It is a longitudinal section showing the structure of the engine mount concerning an embodiment. It is a perspective view which decomposes | disassembles and shows the assembly | attachment states, such as a diaphragm with respect to the partition member of a liquid chamber, a bowl-shaped member, and a disk member. It is sectional drawing which shows the state of a liquid chamber when the 2nd orifice channel | path is open. It is a graph which shows the anti-vibration characteristic of the mount with respect to the low frequency large amplitude vibration input. FIG. 5 is a diagram corresponding to FIG. 4 corresponding to vibration input of high frequency and minute amplitude. FIG. 5 is a diagram corresponding to FIG. 4 corresponding to an input of idle vibration. FIG. 3 is a view corresponding to FIG. 1 according to another embodiment in which a hook-like member and a disk member are sandwiched and fixed between a lower end portion of an outer cylinder member and a bracket. FIG. 3 is a view corresponding to FIG. 2 according to another embodiment using a cap having a short length.

A Engine mount (liquid filled anti-vibration mount device)
F Liquid chamber f1 Pressure receiving chamber f2 Equilibrium chamber f3 Sub liquid chamber P1 First orifice passage P2 Second orifice passage P3 Third orifice passage (communication passage)
V Negative pressure chamber 1 Mounting member 2 Rubber elastic body 3 Casing (supporting member)
4 Partition member 5 Diaphragm 51 Cylindrical part (liquid chamber forming member)
52 recess 53 metal reinforcing plate (reinforcing member)
6 bowl-shaped member 7 disc member 9 cap 91 lid part (lid member)

Claims (4)

An attachment member attached to the supported body, a support member for supporting the attachment member via a rubber elastic body, and a liquid chamber formed between the two members so that the volume changes with deformation of the rubber elastic body; A liquid-filled vibration-proof mount device comprising: a partition member that partitions the liquid chamber into a pressure-receiving chamber and an equilibrium chamber; and a first orifice passage that communicates the pressure-receiving chamber and the equilibrium chamber.
A second orifice passage penetrating the partition member and communicating with the pressure receiving chamber and the equilibrium chamber is provided;
The equilibration chamber includes a lid member made of an elastic film capable of opening and closing an opening on the equilibration chamber side of the second orifice passage, and a liquid chamber that forms a sub liquid chamber in the equilibration chamber integrally with the lid member. Forming member is arranged ,
The lid member, the surface opposite the opening and the opposing surfaces of the second orifice passage, are placed in a state in contact with the liquid facing the the auxiliary liquid chamber,
The liquid-sealed anti-vibration mount device, wherein the liquid chamber forming member is formed with a communication path that communicates the inside of the sub liquid chamber with an external equilibrium chamber . The vibration-proof mount device according to claim 1,
The liquid chamber forming member is integrally formed with a diaphragm partitioning the equilibrium chamber, and includes a bottomed tubular portion extending from the diaphragm toward the partition member and extending through the equilibrium chamber.
The front end opening of the cylindrical portion is closed by a lid member, and a communication path is formed through the peripheral wall portion of the cylindrical portion,
Furthermore, a liquid-filled vibration-proof mount device , wherein a reinforcing member is embedded in at least a part of the bottom part or the peripheral wall part of the cylindrical part . The anti-vibration mount device according to claim 2,
The supported body is an automobile engine,
On the side of the diaphragm opposite to the cylindrical portion, a hook-like member made of an elastic body and bulging toward the diaphragm is preliminarily pressed and biased toward the partition member by its restoring force. Arranged in a compressed state,
A liquid-filled vibration proof mount device , wherein a negative pressure chamber into which intake negative pressure of the engine is guided is defined on an inner peripheral side of the bowl-shaped member . The anti-vibration mount device according to claim 3,
An engagement portion is formed on the diaphragm and the bowl-shaped member so as to engage with each other .

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