JP2010048350A - Fluid-filled vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid-filled vibration isolator of a novel structure capable exercising a vibration isolating effect superior with respect to any vibration of a plurality of different frequency ranges without using an actuator needing supply of external energy. <P>SOLUTION: The fluid-filled vibration isolator is provided with a one-way valve 70 allowing only a fluid flow from a fluid chamber 134 to an intermediate chamber 138, and a hole 90 for static pressure recovery communicating the pressure chamber 134 and the intermediate chamber 138, allowing only a fluid flow amount insufficient for recovering capacity increase of the intermediate chamber 138 following the fluid flow through the one-way valve 70 in an input state of tuning vibration of an orifice passage 142 communicating the pressure chamber 134 with an equilibration chamber 136, and allowing a fluid flow sufficient for recovering the initial capacity of the intermediate chamber 138 in a non-input state of the tuning vibration of the orifice passage 142. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an anti-vibration device used as, for example, an automobile engine mount and the like, and in particular, a fluid-filled vibration-proof vibration device that obtains a vibration-proof effect by utilizing the flow action of an incompressible fluid sealed inside. It relates to the device.

  Conventionally, a fluid-filled vibration isolator has been known as a type of anti-vibration coupling body and anti-vibration support body mounted between members constituting a vibration transmission system. For example, application to an automobile engine mount is known. It is being considered. Such a fluid-filled vibration isolator is generally a pressure receiving chamber in which a first mounting member and a second mounting member are connected by a main rubber elastic body, and a part of the wall portion is configured by the main rubber elastic body. In addition, an equilibrium chamber in which a part of the wall portion is formed of a flexible film is provided, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber. The pressure receiving chamber and the equilibrium chamber are communicated with each other based on a relative pressure fluctuation caused between the pressure receiving chamber and the equilibrium chamber when vibration is input between the first mounting member and the second mounting member. The vibration isolating effect can be exhibited based on the resonance action of the fluid that can flow through the orifice passage formed as described above.

  By the way, in an automobile engine mount, a plurality of vibrations in different frequency ranges are input depending on the traveling state of the vehicle, such as low-frequency vibrations such as engine shake and high-frequency vibrations such as a humming sound during traveling. In some cases, anti-vibration performance is required for a plurality of vibrations in these different frequency ranges.

  However, in a fluid-filled vibration isolator having an orifice passage, with respect to vibrations having a frequency higher than the tuning frequency of the orifice passage, the orifice passage is substantially closed due to an anti-resonance action, resulting in significantly high vibration. As a result, the anti-vibration effect based on the resonance action of the fluid is caused to be springed, and there is a problem that it is difficult to effectively exhibit it only in a narrow frequency range in which the orifice passage is tuned.

  In order to cope with such a problem, for example, in Patent Document 1, a plurality of orifice passages tuned to different frequency ranges are provided, and the plurality of orifice passages are subjected to input vibration by an actuator such as a negative pressure type or an electromagnetic type. There has been proposed a structure in which the function is switched according to the frequency. However, since the structure described in Patent Document 1 requires a special actuator that requires supply of external energy such as negative pressure or electric power for operation, connection to a negative pressure source, a power source, or the like of the actuator is not possible. In addition to the necessity, a control device for controlling the operation is also required, resulting in a problem that the number of parts is extremely increased, the structure and control are complicated, and the manufacturing cost is increased.

  Therefore, as described in Patent Document 2 and the like, a hydraulic pressure absorption mechanism using a difference in amplitude of input vibration has also been proposed. By utilizing the difference in vibration amplitude, the pressure increase in the pressure receiving chamber is significantly increased by the hydraulic pressure absorption action based on the minute displacement of the movable plate and movable film in the high frequency range where the fluid flow resistance of the orifice passage is remarkably increased. This is to suppress the vibration-proof performance. However, in such a structure, the amount of fluid flow in the orifice passage is reduced by the amount corresponding to the hydraulic pressure absorption action by the movable plate or the movable membrane, even when vibration is input in the low frequency range, and the vibration isolation effect by the orifice passage There has been a problem in that there is a risk of reducing the amount of heat.

  Further, Patent Document 3 proposes a structure for opening / closing switching valves of a plurality of orifice passages by utilizing the difference in amplitude of input vibration. However, such a fluid-filled vibration isolator is also complicated in structure and difficult to manufacture. Moreover, even if the plunger is driven by the pressure accumulating mechanism at the time of large amplitude vibration input to operate the switching valve of the orifice passage, it is difficult to selectively express the complete open state and the complete closed state, and the input vibration The switching operation of the anti-vibration characteristic is likely to be unstable depending on the state or the like, and it is difficult to stably switch the target anti-vibration characteristic. In combination with the complicated structure, there is a problem in reliability and durability, and it is difficult to put it into practical use.

Japanese Patent Laid-Open No. 5-118375 JP 2006-97824 A International Publication No. 2004/081408 Pamphlet

  Here, the present invention has been made in the background as described above, and the problem to be solved is to use a simple actuator without using an actuator that requires supply of external energy such as air pressure or electric power. With a small number of parts in the configuration, it exhibits effective anti-vibration effects for vibrations in different frequency ranges, and in particular, prevents high-frequency small-amplitude vibrations while ensuring sufficient orifice effect for low-frequency large-amplitude vibrations. An object of the present invention is to provide a fluid-filled vibration isolator having a novel structure which can improve the vibration effect and can exhibit the vibration isolation effect with high operational reliability and has high practicality.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

  That is, the feature of the first aspect of the present invention is that (a) a first attachment member attached to one member to be vibration-proof connected, and (b) attached to the other member to be vibration-proof connected. A second mounting member, (c) a main rubber elastic body that elastically connects the first mounting member and the second mounting member, and (d) a part of the wall portion by the main rubber elastic body. And a pressure receiving chamber in which an incompressible fluid is enclosed, and (e) a part of the wall portion is made of a flexible film so that the volume is variable. And an equilibrium chamber in which an incompressible fluid is enclosed, (f) an intermediate chamber in which a part of the wall portion is formed of an elastic partition and in which the incompressible fluid is enclosed, and (g) sandwiching the elastic partition An air chamber formed on the opposite side of the intermediate chamber, and (h) an orifice passing through the pressure receiving chamber and the equilibrium chamber. And (i) a pressure fluctuation transmitting member that is disposed between the pressure receiving chamber and the intermediate chamber and transmits a pressure fluctuation of the pressure receiving chamber to the intermediate chamber by allowing a predetermined amount of displacement; j) a one-way valve that allows fluid flow from the pressure receiving chamber to the intermediate chamber but prevents fluid flow from the intermediate chamber to the pressure receiving chamber; and (k) communicates the pressure receiving chamber and the intermediate chamber; In the input state of tuning vibration of the orifice passage, only an insufficient fluid flow amount is allowed to recover the volume increase of the intermediate chamber due to the fluid flow from the pressure receiving chamber to the intermediate chamber through the one-way valve; Static pressure recovery in which the fluid flow resistance is set to allow a fluid flow amount sufficient to restore the initial volume of the intermediate chamber based on the elasticity of the elastic partition wall in the non-input state of the tuning vibration of the orifice passage Fluid-filled vibration isolation It is in the location.

  In the fluid filled type vibration isolator having the structure according to this aspect, for example, the tuning frequency of the orifice passage is set so as to exhibit an effective anti-vibration effect against low frequency large amplitude vibration such as engine shake. . When such low-frequency large-amplitude vibration is input, the displacement of the pressure fluctuation transmission member is limited, and the fluid in the pressure receiving chamber passes through the one-way valve due to the positive pressure generated in the pressure receiving chamber. It is allowed to flow into the intermediate chamber. As a result, the volume of the intermediate chamber is increased, and the elastic partition is brought closer to the opposing wall surface of the air chamber.

  The elastic partition attempts to recover to the initial state before vibration input by its own elasticity, but the fluid that has flowed from the pressure receiving chamber to the intermediate chamber through the one-way valve is transferred from the intermediate chamber to the pressure receiving chamber by the one-way valve. The flow rate of fluid through the static pressure recovery hole is the volume of the intermediate chamber accompanying the fluid flow from the pressure receiving chamber to the intermediate chamber through the one-way valve in the input state of the tuning vibration of the orifice passage. Only an insufficient amount of flow is allowed to recover the increase, and preferably exhibits a flow resistance that is so great that it becomes substantially occluded. Therefore, the rapid recovery of the intermediate chamber to the initial volume before the vibration input is limited, and before the elastic partition wall recovers to the initial state before the vibration input, further fluid is supplied to the intermediate chamber through the one-way valve by the vibration input. It is made to flow. As a result, the elastic partition is maintained in a restrained state in which recovery to the initial state is limited, and the wall spring rigidity is increased.

  As a result, the change in volume of the intermediate chamber is limited when low frequency large amplitude vibration is input. Therefore, a relative pressure fluctuation is effectively generated between the pressure receiving chamber and the equilibrium chamber, and the amount of fluid flowing through the orifice passage communicating with the pressure receiving chamber and the equilibrium chamber can be effectively ensured. As a result, for example, an anti-vibration effect (high damping effect) due to the flow action of the fluid that flows through the orifice passage against low-frequency large-amplitude vibration such as engine shake is effectively exhibited.

  The amount of fluid flowing through the static pressure recovery hole is allowed to be sufficient to recover the increase in the volume of the intermediate chamber based on the elasticity of the elastic partition wall in the non-input state of the tuning vibration of the orifice passage. ing. As a result, when the input of low-frequency large-amplitude vibration in which the orifice passage is tuned is eliminated, fluid flow through the static pressure recovery hole is allowed, and the static pressure between the pressure receiving chamber and the intermediate chamber gradually increases. Will be recovered.

  On the other hand, in a non-input state of vibration in the tuning frequency range where the vibration isolation effect is exerted by the fluid action of the fluid flowing through the orifice passage, for example, in the non-input state of the engine shake, high-frequency small-amplitude vibration such as traveling booming noise Is input, the displacement of the pressure fluctuation transmission member is allowed, and the pressure fluctuation of the pressure receiving chamber is transmitted to the intermediate chamber by the displacement of the pressure fluctuation transmission member. In this case, since the elastic partition wall is formed with an air chamber on one side thereof, elastic deformation is relatively easily permitted. Therefore, recovery based on the elasticity of the elastic partition wall, that is, volume change of the intermediate chamber is allowed. The pressure fluctuation in the pressure receiving chamber is transmitted to the intermediate chamber and released. Thus, in this aspect, the hydraulic pressure absorption mechanism is configured to include the pressure fluctuation transmission member and the elastic partition wall, and for example, vibration isolation by the hydraulic pressure absorption mechanism that is applied to high-frequency and small-amplitude vibrations such as traveling noise. The effect (vibration insulation effect based on the low dynamic spring) can be effectively exhibited.

  Here, the static pressure recovery hole allows a fluid flow amount sufficient to restore the initial volume of the intermediate chamber based on the elasticity of the elastic partition wall in the input state of high frequency small amplitude vibration such as traveling noise. It may be set to. According to this, even if the volume of the intermediate chamber is changed from the initial state by the inflow or outflow of the fluid after the input of the traveling boom noise is canceled, the intermediate chamber and the pressure receiving chamber are connected through the static pressure recovery hole. The initial volume of the intermediate chamber is restored by allowing fluid flow therebetween. More preferably, the static pressure recovery hole is substantially closed even in an input state of high-frequency small-amplitude vibration such as traveling noise, which is expected to reduce the pressure of the pressure receiving chamber by the pressure fluctuation transmission member. It may be one that exhibits a large flow resistance. According to this, as in the input state of low-frequency large-amplitude vibration such as the engine shake described above, the static pressure recovery hole is substantially closed in the input state of the traveling boom noise, and the pressure receiving chamber The hydraulic pressure absorbing action of the pressure fluctuation transmission member based on the internal pressure fluctuation is effectively exhibited. Moreover, even if the volume of the intermediate chamber is changed from the initial state by the inflow or outflow of the fluid after the input of the traveling boom noise is eliminated, the intermediate chamber is passed through the static pressure recovery hole based on the elasticity of the elastic partition wall. The fluid flow is allowed between the pressure chamber and the pressure receiving chamber, and the volume of the intermediate chamber is gradually restored to the initial state.

  Thereby, in the fluid filled type vibration isolator having the structure according to this aspect, a plurality of components with a simple configuration and a small number of parts can be provided without providing an actuator or the like that requires supply of external energy such as air pressure or electric power. The anti-vibration effect can be exhibited with respect to vibrations in different frequency regions.

  In particular, according to this aspect, since the configuration is simple, it is possible to realize the switching operation of the anti-vibration characteristic according to the input vibration in different frequency regions with high reliability and durability, and excellent practical use. It is possible to provide a fluid-filled vibration isolator having a property. In addition, particularly in this embodiment, a vibration-proof characteristic switching structure including a one-way valve and a static pressure recovery hole is provided in a liquid chamber cut off from the external space. Therefore, the influence of dust and the like can be avoided, and better operational stability and durability can be ensured.

  According to a second aspect of the present invention, in the fluid filled type vibration damping device according to the first aspect, an air opening hole is provided for communicating the air chamber with the atmosphere, and the elastic partition wall is provided in the air chamber. The inner surface of the intermediate wall is in contact with at least a part of the elastic partition wall due to the increase in volume of the intermediate chamber accompanying fluid flow from the pressure receiving chamber to the intermediate chamber through the one-way valve in the input state of tuning vibration of the orifice passage. It is characterized by the contact surface being in contact.

  According to this aspect, the restraint state of the elastic partition wall can be maintained more firmly by bringing the elastic partition wall into contact with the contact surface. As a result, the volume change of the intermediate chamber can be more firmly limited, and the amount of fluid flowing through the orifice passage can be secured more stably.

  According to a third aspect of the present invention, in the fluid-filled vibration isolator according to the second aspect, the elastic partition defining the air chamber is a curved convex shape that swells in a substantially dome shape toward the intermediate chamber. In addition, the inner surface of the air chamber facing the elastic partition wall has a curved concave shape that is recessed toward the opposite side of the elastic partition wall.

  According to this aspect, at the time of inputting a low-frequency large-amplitude vibration such as an engine shake, for example, the elastic partition wall can be clearly changed to a convex shape toward the opposed inner surface on the air chamber side. Then, by forming the facing surface of the air chamber into a curved concave shape substantially corresponding to the elastic partition wall, when the elastic partition wall is protruded toward the facing surface of the air chamber, the elastic partition wall becomes the facing surface of the air chamber. On the other hand, it becomes easy to make contact and restrain in a wide range. On the other hand, since the elastic partition wall is substantially dome-shaped, when the elastic partition wall is restored to the initial state, the elastic partition wall is projected into the intermediate chamber by positively using the restoring force of the elastic partition wall. It can be restored quickly. As a result, the switching operation between the operation state of the orifice passage when the air chamber disappears and the operation state of the hydraulic pressure absorption mechanism when the air chamber is present can be realized more reliably and with high reliability. .

  According to a fourth aspect of the present invention, in the fluid filled type vibration damping device according to any one of the first to third aspects, in the one-way valve, a relative positive pressure of the pressure receiving chamber with respect to the intermediate chamber. It is characterized in that a preload is set to keep the closed state until becomes a predetermined value.

  According to this aspect, for example, in a state in which the tuning vibration of the orifice passage is set to a low frequency large amplitude vibration such as an engine shake, a high frequency small amplitude vibration such as a traveling boom noise that deviates from the tuning vibration of the orifice passage is input. In this case, the fluid flow from the pressure receiving chamber to the intermediate chamber can be prevented by the preload of the one-way valve. Thereby, the volume of the air chamber is maintained by suppressing the increase in the volume of the intermediate chamber, and the hydraulic pressure absorption effect based on the elastic deformation of the elastic partition wall through the pressure fluctuation transmission member can be more stably exhibited.

  In addition, the setting of the preload in this aspect can be performed by, for example, a check valve, and a structure in which a valve body that opens in one direction is biased in a closing direction by a biasing means such as a coil spring or rubber is adopted Can be done.

  According to a fifth aspect of the present invention, in the fluid-filled vibration isolator according to any one of the first to fourth aspects, a fluid flow path in which a fluid flow is generated based on a displacement of the pressure fluctuation transmission member. And the fluid flow path is tuned to a higher frequency range than the orifice passage.

  According to this aspect, when a vibration that restricts the displacement of the pressure fluctuation transmission member is input, fluid flow through the orifice passage is expressed, while when a vibration that allows the displacement of the pressure fluctuation transmission member is input, the fluid flow Fluid flow through the channel is developed. Therefore, for example, the orifice passage is tuned to the frequency range of the engine shake, and the fluid passage is tuned to a higher frequency range of the traveling booming noise. While exhibiting an effect, the vibration isolation effect by a fluid flow path can be exhibited with respect to a traveling noise that is higher than that. Thereby, the orifice passage and the fluid flow path are switched in accordance with vibration inputs in a plurality of different frequency ranges, and an effective anti-vibration effect can be obtained for any of the vibrations in the plurality of frequency ranges.

  According to a sixth aspect of the present invention, in the fluid-filled vibration isolator according to any one of the first to fifth aspects, the second attachment member includes a cylindrical portion, and the cylindrical portion One opening portion side of the cylindrical portion is closed by the main rubber elastic body that is disposed on one opening portion side of the first body and that connects the first mounting member and the second mounting member. On the other hand, the other opening of the cylindrical portion is closed with the flexible membrane, and an incompressible fluid sealing region is provided between the opposing surfaces of the main rubber elastic body and the flexible membrane. And a partition member is disposed between the opposing surfaces of the main rubber elastic body and the flexible membrane and supported by the cylindrical portion, and between the partition member and the main rubber elastic body. The pressure receiving chamber is formed at the same time, and the equilibrium chamber is formed between the partition member and the flexible membrane. , Said said intermediate chamber inside the partition member air chamber is formed, characterized.

  According to this aspect, the pressure receiving chamber and the equilibrium chamber, and the air chamber and the intermediate chamber can be configured compactly in the cylindrical portion. In addition, in this aspect, the aspect by which the outer peripheral surface of the said partition member is exposed to external space more suitably may be employ | adopted. In this way, communication with the external space of the air chamber can be performed more easily.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows an automobile engine mount 10 as an embodiment of a fluid filled type vibration damping device according to the present invention. The engine mount 10 has a structure in which a first mounting bracket 12 as a first mounting member and a second mounting bracket 14 as a second mounting member are elastically connected by a main rubber elastic body 16. The first mounting bracket 12 is mounted on the power unit side, while the second mounting bracket 14 is mounted on the vehicle body side, so that the power unit is supported in an anti-vibration manner with respect to the body.

  FIG. 1 shows a state in which the engine mount 10 is not attached to the automobile. However, in this embodiment, the shared support load of the power unit is input in the mount axis direction (up and down in FIG. 1) in the attached state. Is done. Therefore, in the mounted state, the main vibration to be vibrated is input substantially in the mount axis direction, and the first mounting bracket 12 and the second mounting bracket 14 are pivoted based on the elastic deformation of the main rubber elastic body 16. It will be displaced in the direction which mutually approaches in a direction. In the following description, the vertical direction means the vertical direction in FIG. 1 unless otherwise specified.

  More specifically, the first mounting member 12 has a substantially circular block shape, and a disk-shaped portion 18 that extends radially outward is integrally formed at the upper end in the axial direction. Further, a bolt hole 20 opening upward is formed on the central axis of the first mounting bracket 12, and the first mounting bracket 12 is illustrated by a fixing bolt (not shown) screwed into the bolt hole 20. Not to be fixed to the power unit of the car.

  On the other hand, the second mounting bracket 14 has a large-diameter substantially stepped cylindrical shape, and the upper portion is a large-diameter cylindrical portion 24 across a step portion 22 formed in an axially intermediate portion. On the other hand, the lower portion is a small diameter cylindrical portion 26 having a smaller diameter than the large diameter cylindrical portion 24. The large diameter cylindrical portion 24 and the small diameter cylindrical portion 26 constitute a cylindrical portion of the second mounting bracket 14. Further, the first mounting bracket 12 is spaced apart from the opening side of one of the cylindrical portions of the second mounting bracket 14 (upward in FIG. 1), and the central axes of both the brackets 12 and 14 are substantially on the same line. The main rubber elastic body 16 is disposed between the first mounting bracket 12 and the second mounting bracket 14.

  The main rubber elastic body 16 has a large-diameter substantially truncated cone shape, and its small-diameter side end surface is vulcanized and bonded to the outer peripheral surface of the first mounting member 12. Further, the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16 is vulcanized and bonded to the inner peripheral surface of the large-diameter cylindrical portion 24 and the step portion 22 of the second mounting bracket 14. Thereby, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14. The first mounting bracket 12 and the second mounting bracket 14 are elastically connected to each other by the main rubber elastic body 16 and one side of the second mounting bracket 14 on the large-diameter cylindrical portion 24 side ( The upper opening in FIG. 1 is fluid-tightly closed by the main rubber elastic body 16. A large mortar-shaped recess 30 having a substantially mortar shape that opens downward is formed on the large-diameter side end face of the main rubber elastic body 16. Further, a thin seal rubber layer 32 integrally formed with the main rubber elastic body 16 is formed on the inner peripheral surface of the small diameter cylindrical portion 26 of the second mounting bracket 14 with a substantially constant thickness. It is formed. A positioning step 33 that slightly protrudes inward in the radial direction is formed at the upper end portion of the seal rubber layer 32.

  Further, in the integrally vulcanized molded product of the main rubber elastic body 16 provided with the first and second mounting brackets 12 and 14, from the other opening side of the second mounting bracket 14 (downward in FIG. 1). A partition member 34 is assembled. The partition member 34 is a divided structure formed by combining a plurality of members, and includes an upper partition member 36 and a lower partition member 38.

  The upper partition member 36 has a generally cup shape that opens downward as a whole, and the overall outer diameter dimension is smaller than the inner diameter dimension of the small diameter cylindrical portion 26 of the second mounting bracket 14. The upper partition member 36 is formed using a hard synthetic resin material or the like in the present embodiment. The upper partition member 36 is formed with a large-diameter central recess 40 that opens in the center of the lower surface as a recess. The inner peripheral surface of the peripheral wall portion of the central recess 40 has an axial direction (depth direction). ), An annular stepped portion 42 is formed extending outward in the direction perpendicular to the axis. As a result, the center recess 40 has an inner diameter dimension on the upper bottom side (upper side in FIG. 1) sandwiching the stepped portion 42, and an inner diameter dimension on the opening side (lower side in FIG. 1) sandwiching the stepped portion 42. Has been smaller than.

  In addition, a circumferential groove 44 is formed in the peripheral wall portion of the upper partition member 36 and is open to the outer peripheral surface and extends in the circumferential direction with a predetermined length (for example, less than one round in the present embodiment). The circumferential groove 44 has one end opened upward through a notched communication window 46 formed at the upper end of the upper partition member 36, and the other end is the lower end of the upper partition member 36. It is opened downward through a communication hole 48 penetrating in the part.

  Further, a groove-like communication groove 50 is formed at one place on the circumference of the peripheral wall of the upper partition member 36 and opens in the upper end surface of the peripheral wall and extends in the radial direction of the upper partition member 36. The communication groove 50 is opened above the peripheral wall, and the radially inner end of the upper partition member 36 is opened at the upper end portion of the inner peripheral surface of the central recess 40.

  A shallow upper recess 52 that opens upward is formed on the upper surface of the upper wall portion of the upper partition member 36. The inner diameter dimension of the upper recess 52 is slightly smaller than the inner diameter dimension on the upper bottom side (upper side in FIG. 1) than the step portion 42 in the central recess 40, and the peripheral wall portion of the upper recess 52 Is an annular projecting portion 54 that protrudes upward.

  A lid member 56 is superimposed from above the upper recess 52. The lid member 56 has an outer diameter dimension substantially equal to the outer diameter dimension of the upper partition member 36 and has a substantially cup shape that opens to one side, and is formed of a hard material such as a synthetic resin material. The lid member 56 is overlapped with the upper surface of the upper partition member 36 so that the openings thereof are aligned with each other, and the front end surfaces of the annular protrusion 54 of the upper partition member 36 and the outer peripheral wall portion of the lid member 56 are overlapped. Are overlapped with each other and fixed by welding or bonding. Thereby, the bottom surface of the upper recess 52 of the upper partition member 36 and the top bottom surface of the lid member 56 are opposed to each other in parallel with a predetermined distance in the vertical direction with a substantially circular flat surface. A hollow constraining area 58 is formed between the surfaces.

  Note that the bottom wall portion of the upper recess 52 and the upper bottom portion of the recess of the lid member 56 that constitute the upper and lower walls of the restraining arrangement region 58 are both transparent through a large number of small holes. The hole 60 is formed so as to penetrate in the thickness direction. Through these through holes 60, the constraining area 58 is communicated with the upper and lower external areas.

  Furthermore, a movable plate 62 as a pressure fluctuation transmission member is accommodated in the restraint arrangement region 58. The movable plate 62 has a thin and substantially disk shape formed using a rubber elastic material. The movable plate 62 has a thickness dimension smaller than the distance between the opposing surfaces of the upper and lower wall portions of the restraining arrangement region 58 and is restrained. The outer diameter is smaller than the inner diameter of the arrangement region 58. In particular, in the present embodiment, the upper and lower surfaces of the movable plate 62 are provided with a undulating surface large enough to be visually observed by providing a plurality of irregularities or a plurality of irregularities.

  Further, a pair of central shaft portions 64 projecting on both sides in the axial direction are integrally formed at the central portion of the movable plate 62. Each central shaft portion 64 is inserted so as to be displaceable with respect to an insertion hole penetrating on each central shaft of the upper partition member 36 and the lid member 56. As a result, the movable plate 62 is positioned substantially at the center of the restraint arrangement region 58, and the restraint placement is performed by a distance corresponding to the difference between the thickness dimension of the movable plate 62 and the height dimension of the restraint placement region 58. It can be displaced in the axial direction within the installation area 58. The amount of displacement of the movable plate 62 in the axial direction is limited by abutting against the upper and lower inner surfaces of the restraining arrangement region 58. At the time of such abutment, the amount of displacement is buffered based on the elasticity of the movable plate 62 itself. The function is demonstrated and the sound and impact are buffered.

  In addition, an outer opening 66 that opens toward the lower surface and the outer peripheral surface is formed at one location on the periphery of the outer peripheral wall portion of the lid member 56. A channel hole 68 that penetrates the lid member 56 in the axial direction is formed in the upper bottom 67 of the outer opening 66.

  A check valve 70 as a one-way valve is provided below the upper bottom 67 in the outer opening 66. As shown in FIG. 2, the check valve 70 includes a rubber valve body 72 as a valve body and a metal leaf spring 74 as an urging means. 1 corresponds to the II cross section in FIG.

  The rubber valve body 72 is integrally formed with a locking projection 78 having a substantially truncated truncated cone shape at the central portion of a main body 76 having a disk shape having a diameter larger than the diameter of the flow path hole 68. . A constricted portion 80 is formed between the main body portion 76 and the locking projection 78.

  On the other hand, the metal leaf spring 74 is formed from a thin stainless steel plate, a spring steel plate, or the like, and has a rectangular flat plate shape as a whole. Further, a locking hole 82 is provided through one end of the metal plate spring 74 in the longitudinal direction. In the present embodiment, a plurality of incisions extending radially outward are formed at equal intervals in the circumferential direction with respect to the inner peripheral edge portion of the locking hole 82. A plurality of rising pieces 86 are formed at the peripheral edge. Furthermore, a substantially circular mounting hole 84 is provided through the other end. The diameter of the mounting hole 84 is slightly larger than the diameter of the constricted portion 80 of the rubber valve body 72.

  Then, the locking protrusion 78 of the rubber valve body 72 is inserted into the mounting hole 84 from the small diameter end side, and the constricted portion 80 is positioned in the mounting hole 84, whereby the locking protrusion 78 and the main body portion. 76 is attached to the metal plate spring 74 at a position sandwiching the metal plate spring 74 in the thickness direction. In other words, the rubber valve body 72 is attached to the metal plate spring 74 in a state where the locking projection 78 is locked to the metal plate spring 74.

  In this way, the metal leaf spring 74 to which the rubber valve body 72 is attached has a locking projection 88 formed to protrude downward from the upper bottom 67 of the outer opening 66 in the lid member 56 with respect to the locking hole 82. The tip of each rising piece 86 overlaps the outer peripheral surface of the locking projection 88 in a state where the plurality of rising pieces 86 formed on the inner peripheral edge of the locking hole 82 are elastically deformed by being inserted. It has been. As a result, the locking projections 88 are locked to the locking holes 82 in the direction in which they are separated from each other in the overlapping direction of the upper bottom 67 and the metal leaf spring 74.

  In the state where the metal leaf spring 74 is mounted on the upper bottom portion 67, the main body portion 76 of the rubber valve body 72 is sandwiched between the upper bottom portion 67 and the metal leaf spring 74, and below the flow path hole 68 of the upper bottom portion 67. It is located in. There, the tip end portion of the metal leaf spring 74 to which the rubber valve body 72 is attached is elastically deformed into a state separated from the upper bottom portion 67 by the thickness of the main body portion 76 of the rubber valve body 72. As a result, a pressing force based on the elastic force of the metal leaf spring 74 is exerted on the main body 76 of the rubber valve body 72, the main body 76 is pressed against the opening peripheral edge of the flow path hole 68, and the flow path hole 68 is formed. It is designed to be kept closed.

  The upper partition member 36 is formed with a leak hole 90 as a static pressure recovery hole that penetrates the upper partition member 36 and the lid member 56 in the axial direction when the lid member 56 is overlapped. The leak hole 90 is a communication hole extending in the axial direction of the upper partition member 36 and the lid member 56, and one end portion is opened at the upper end surface of the lid member 56, and the other end portion is the upper partition member. 36 is opened on the inner peripheral surface of the central recess 40.

  Here, as will be described later, a pressure receiving chamber 134 in which an incompressible fluid is enclosed is formed on the upper surface of the lid member 56, while an incompressible fluid is enclosed in the central recess 40 of the upper partition member 36. An intermediate chamber 138 is formed, and the leak hole 90 communicates with the pressure receiving chamber 134 and the intermediate chamber 138. The check valve 70 is disposed on a flow path that connects the pressure receiving chamber 134 and the intermediate chamber 138. Furthermore, the pressure receiving chamber 134 and the equilibrium chamber 136 in which the incompressible fluid is sealed are communicated with each other by an orifice passage 142 that extends in the circumferential direction on the outer periphery of the partition member 34. It is tuned to exhibit an effective anti-vibration effect against low-frequency large-amplitude vibration such as engine shake.

  Here, the flow amount of the fluid allowed by the leak hole 90 is from the pressure receiving chamber 134 through the check valve 70 to the intermediate chamber at least in the input state of low-frequency large-amplitude vibration such as engine shake which is the tuning vibration of the orifice passage 142. In the non-input state of the low-frequency large-amplitude vibration, only an insufficient fluid flow is allowed to recover the volume increase of the intermediate chamber 138 due to the fluid flow introduced into the fluid 138, and based on the elasticity of the movable rubber film 112. Thus, the fluid flow resistance is set so as to allow a fluid flow amount sufficient to restore the initial volume of the intermediate chamber 138. More preferably, in the engine mount 10 having the hydraulic pressure absorbing mechanism including the movable plate 62 as in the present embodiment, the leak hole 90 has a vibration input state in the tuning frequency range of the orifice passage 142, A fluid flow resistance that allows only a fluid flow that is insufficient to recover the volume increase of the intermediate chamber 138 is set even in a vibration input state in a frequency range where the pressure reducing effect of the pressure receiving chamber 134 is expected by the hydraulic pressure absorbing mechanism. Is done. The fluid flow rate sufficient to restore the initial volume of the intermediate chamber 138 in the non-input state of the vibration in the tuning frequency region of the orifice passage 142 and the vibration in the frequency region where the vibration isolation effect by the hydraulic pressure absorption mechanism is expected. The fluid flow resistance that allows

  That is, the leak hole 90 has a flow resistance larger than the fluid flow resistance from the pressure receiving chamber 134 to the intermediate chamber 138 in at least the one-way valve, and has a low frequency large amplitude such as an engine shake in which the orifice passage 142 is tuned. When vibration is input, the amount of fluid discharged to the intermediate chamber 138 on the positive side relative to the intermediate chamber 138 of the pressure receiving chamber 134 flows into the intermediate chamber 138 on the negative side relative to the intermediate chamber 138 of the pressure receiving chamber 134 by the same amount. It is required to be large enough to be sufficient. Preferably, the pressure receiving chamber 134 is used at the time of vibration input in the frequency range where the pressure reduction effect of the pressure receiving chamber 134 by the hydraulic pressure absorbing mechanism configured including the movable plate 62 and the vibration input in the tuning frequency range of the orifice passage 142 is expected. And the intermediate chamber 138 exhibit a flow resistance that is so large that a substantial blockage occurs. On the other hand, when a static pressure exists between the pressure receiving chamber 134 and the intermediate chamber 138, the fluid resistance is such that the static pressure can be eliminated.

  In short, if the leak hole 90 is regarded as an orifice passage communicating with the pressure receiving chamber 134 and the intermediate chamber 138, the tuning frequency of the orifice passage constituted by the leak hole 90 is the orifice passage 142 formed on the outer periphery of the partition member 34. The tuning frequency of the orifice passage 142 is set to be sufficiently lower than the frequency at which the vibration damping effect by the hydraulic pressure absorbing mechanism constituted by the movable plate 62 is expected. For example, the tuning frequency of the orifice passage 142 corresponds to the engine shake. When the frequency at which the anti-vibration effect by the hydraulic pressure absorbing mechanism is expected to be about 10 Hz is about 130 Hz, which corresponds to traveling noise, it can be considered that the frequency is set to about 1 Hz, which is lower than that frequency. At the time of vibration input such as engine shake or traveling boom noise, the leak hole 90 is in a substantially closed state. On the other hand, the vibration input is canceled and the pressure receiving chamber 134 and the intermediate chamber 138 are not connected. When a static pressure due to a hydraulic pressure difference is generated, fluid flow through the leak hole 90 is allowed, so that the static pressure (hydraulic pressure difference) between the pressure receiving chamber 134 and the intermediate chamber 138 is gradually recovered. It is.

  Note that the fluid flow resistance of the leak hole 90 is appropriately adjusted by, for example, adjusting the cross-sectional area of the leak hole 90 or the size of the flow path length, or making the flow path shape a bent shape. In particular, in the present embodiment, the leak hole 90 has an axial direction of the upper partition member 36 having a substantially constant circular cross-sectional shape smaller than the communication groove 50 and the flow path hole 68 constituting the flow path in which the check valve 70 is disposed. The communication hole extends straight.

  And the lower partition member 38 is overlapped with the upper partition member 36 having such a structure from below in the axial direction. The lower partition member 38 has a thick, substantially disk shape having substantially the same outer dimensions as the upper partition member 36, and is formed using a hard synthetic resin material. The lower partition member 38 is formed with a lower recess 94 that opens to the center of the lower surface. In addition, a shallow dish-shaped central protrusion 96 is integrally formed at the center of the upper end portion of the lower partition member 38.

  On the outer peripheral surface on the base end side of the central protrusion 96, a fitting groove 98 extending in the circumferential direction over the entire circumference is formed. In addition, a communication passage 100 penetrating in the axial direction is formed in the outer peripheral portion of the lower partition member 38 at a position corresponding to the opening of the communication hole 48 of the upper partition member 36 when superimposed on the upper partition member 36. Has been. The communication passage 100 is opened on the upper end surface of the lower partition member 38 and the inner surface of the lower recess 94 on both sides in the axial direction.

  Furthermore, a concave groove-like upper fitting groove 102 extending continuously over substantially the entire circumference in the circumferential direction is formed at the upper end in the axial direction on the outer peripheral surface of the lower partition member 38. On the other hand, a lower fitting groove 104 having a concave groove shape extending continuously over the entire circumference in the circumferential direction is formed at the lower end in the axial direction on the outer peripheral surface of the lower partition member 38.

  In addition, a contact surface 106 having a curved surface shape that is concave toward the upper side in the axial direction of the lower partition member 38 is formed on the upper end surface of the central protrusion 96. The contact surface 106 has a substantially circular shape when viewed from above, and particularly in this embodiment, the contact surface 106 has a curved surface with a substantially constant curvature over the entire surface.

  An air passage 108 serving as an air release hole is opened at one place on the outer periphery of the contact surface 106. The air passage 108 is a substantially L-shaped passage that extends outward in the radial direction by being bent after being extended substantially downward in the axial direction at the outer peripheral portion of the contact surface 106. One end portion is opened on the contact surface 106, and the other end portion is opened on the outer peripheral surface of the lower partition member 38.

  A partition wall member 110 is disposed above the lower partition member 38 so as to cover the central protrusion 96. The partition member 110 is configured by vulcanizing and bonding a fitting ring 114 to an outer peripheral edge portion of a movable rubber film 112 as an elastic partition wall.

  The movable rubber film 112 has a substantially disk shape as a whole, and has a tapered shape which is slightly positioned so as to be gradually positioned upward in the radial direction toward the center in the radial direction. The outer peripheral edge of the movable rubber film 112 is attached to the inner peripheral surface of the fitting ring 114 having a substantially annular shape. As a specific shape of the movable rubber film 112, for example, the shape disclosed in Japanese Patent Application Laid-Open No. 2008-32055 can be suitably employed.

  The inner peripheral surface of the fitting ring 114 is attached to the outer peripheral edge of the movable rubber film 112 having such a shape. The fitting ring 114 has a thin, substantially cylindrical shape, and is formed of a metal material such as iron or an aluminum alloy. A locking projection 116 that extends radially inward over the entire circumference is integrally formed at one end (downward in this embodiment) of the fitting ring 114 in the axial direction.

  Further, a sealing lip 118 protruding upward in the axial direction is attached to the upper end of the fitting ring 114 in the axial direction. The seal lip 118 is formed integrally with the movable rubber film 112, and is continuously formed in the circumferential direction with a substantially constant chevron cross-sectional shape over the entire circumference.

  The axially lower end portion of the fitting ring 114 in the partition wall member 110 having such a structure is extrapolated to the central protrusion 96 of the lower partition member 38, and the lower portion of the fitting ring 114 from the axially intermediate portion. On the other hand, the locking protrusion 116 is locked and fixed to the fitting groove 98 of the central protrusion 96 by performing diameter reduction processing such as an eight-way drawing. Thereby, the upper part of the opening of the central protrusion 96 is fluid-tightly covered with the movable rubber film 112, and the entire contact surface 106 is opposed to the movable rubber film 112, which is the bottom of the central protrusion 96. An air chamber 120 is formed between the contact surface 106 and the movable rubber film 112. Here, since a part of the wall portion of the air chamber 120 is made of the movable rubber film 112, a predetermined volume is set by the elasticity of the movable rubber film 112. A predetermined volume is secured under static pressure by being held away from the contact surface 106 of the chamber 120.

  Further, the upper partition member 36 is superimposed on the upper surface of the lower partition member 38, so that the fitting ring 114 is fitted into the central recess 40 of the upper partition member 36. Further, the upper end portion of the fitting ring 114 presses the seal lip 118 against the step portion 42 of the central recess 40 in the axial direction. Thereby, the space between the fitting ring 114 and the upper partition member 36 is fluid-tightly sealed in the axial direction by the seal lip 118 over the entire circumference. Although not apparent from the drawings, the upper partition member 36 and the lower partition member 38 are assembled to each other by engaging the engagement pieces formed on the opposing surfaces with the engagement grooves. ing.

  Thus, the partition member 34 configured to include the upper partition member 36 and the lower partition member 38 overlapped in the axial direction in this way is inserted into the small diameter cylindrical portion 26 of the second mounting member 14 from below. It is done. Then, the upper end surface of the lid member 56 is superimposed on the positioning step portion 33 formed on the seal rubber layer 32, whereby the partition member 34 is positioned in the axial direction with respect to the second mounting bracket 14. In this positioning state, the lower partition member 38 is in a state in which only the upper portion from the central projection 96 is fitted into the second mounting member 14, and the opening of the air passage 108 is the second portion. It is positioned below the lower end of the mounting bracket 14 and exposed to the external space.

  Then, by reducing the diameter of the small-diameter cylindrical portion 26 of the second mounting bracket 14 such as eight-way drawing, the outer peripheral surfaces of the upper and lower partition members 36 and 38 are the inner peripheral surfaces of the small-diameter cylindrical portion 26. A fitting protrusion that is fluid-tightly superimposed on the inner peripheral surface of the small-diameter cylindrical portion 26 via a seal rubber layer 32 that is attached to the outer periphery of the small-diameter cylindrical portion 26 and extends radially inward at the lower end edge of the small-diameter cylindrical portion 26. 124 is fitted into the upper fitting groove 102 of the lower partitioning member 38 and is locked and fixed. As a result, the partition member 34 is supported by the small-diameter cylindrical portion 26 of the second mounting bracket 14 and is fitted and fixed to the second mounting bracket 14.

  On the other hand, a diaphragm 126 as a flexible film is assembled to the lower end portion of the lower partition member 38 exposed from the second mounting bracket 14. Diaphragm 126 is formed of a thin, substantially disk-shaped rubber elastic film that is easily deformed by having a sufficient slack in the central portion.

  A large-diameter cylindrical fixing fitting 128 is vulcanized and bonded to the outer peripheral edge portion (the outer peripheral surface in the present embodiment) of the diaphragm 126. A fitting protrusion 130 is integrally formed at the upper end opening of the fixing bracket 128 so as to extend radially inward in a flange shape over the entire circumference. In addition, a thin seal rubber layer integrally formed with the diaphragm 126 is formed on the inner peripheral surface of the fixing metal 128.

  Then, the fixing bracket 128 is extrapolated to the lower partition member 38 from below in the axial direction, and thereafter, the fixing bracket 128 is subjected to diameter reduction processing. As a result, the inner peripheral surface of the upper end portion of the fixing bracket 128 has the other axial end of the lower partitioning member 38 protruded axially outward from the second mounting bracket 14 via the seal rubber layer (in FIG. 1). , Downward) is fixedly fitted on the outer peripheral surface of the end portion. Then, the fitting protrusion 130 of the fixing metal 128 is fitted into the lower fitting groove 104 of the lower partition member 38 and locked.

  Thereby, the opening of the lower recess 94 of the lower partition member 38 is covered with the diaphragm 126 in a fluid-tight manner, and the other (downward in FIG. 1) of the second mounting bracket 14 on the small diameter cylindrical portion 26 side. The opening is fluid-tightly closed with a diaphragm 126. Further, the partition member 34 is disposed between the axially opposing surfaces of the main rubber elastic body 16 and the diaphragm 126.

  Here, a fluid chamber 132 is formed between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 126 as an incompressible fluid sealing region that is sealed with respect to the external space. Incompressible fluid is enclosed. As the incompressible fluid sealed in the fluid chamber 132, for example, water, alkylene glycol, polyalkylene glycol, silicone oil, or the like is adopted. However, the vibration damping effect based on the fluid action such as the resonance action of the fluid is particularly preferable. In order to obtain it effectively, it is desirable to employ a low viscosity fluid of 0.1 Pa · s or less.

  The incompressible fluid is sealed in the fluid chamber 132 by, for example, assembling the upper partition member 36 and the lower partition member 38 in the atmosphere and sealing the opening to the external space of the air passage 108 with a stopper. In this state, the integrally vulcanized molded product of the main rubber elastic body 16 having the first and second mounting brackets 12 and 14, the integrally vulcanized molded product of the diaphragm 126 and the partition member 34 are assembled in an incompressible fluid. After doing so, it is advantageously realized, for example, by removing the plug of the air passage 108 in the atmosphere.

  Furthermore, the fluid chamber 132 is vertically divided into two in the axial direction by disposing the partition member 34 so as to expand in the direction perpendicular to the axis. Between the partition member 34 and the main rubber elastic body 16, a part of the wall portion is constituted by the main rubber elastic body 16, and vibration between the first mounting bracket 12 and the second mounting bracket 14 is performed. A pressure receiving chamber 134 is formed in which a pressure fluctuation is generated based on elastic deformation of the main rubber elastic body 16 at the time of input. On the other hand, between the partition member 34 and the diaphragm 126, a part of the wall portion is constituted by the diaphragm 126, and an equilibrium chamber 136 in which a volume change is easily allowed based on elastic deformation of the diaphragm 126 is formed. . The pressure receiving chamber 134 and the equilibrium chamber 136 are filled with an incompressible fluid.

  Further, the internal space formed between the upper partition member 36 and the lower partition member 38 is partitioned inside the partition member 34 by the movable rubber film 112 to form two internal spaces. The internal space formed between the upper partition member 36 and the movable rubber film 112 is an intermediate chamber 138 in which a part of the wall is formed of the movable rubber film 112, while the lower partition member 38 An internal space formed between the movable rubber films 112 is an air chamber 120 in which a part of the wall is formed of the movable rubber film 112. Thereby, inside the partition member 34, an intermediate chamber 138 is formed above the movable rubber film 112, and an air chamber 120 is formed below.

  As described above, in the engine mount 10 according to the present embodiment, the equilibrium chamber 136 is formed on the opposite side of the pressure receiving chamber 134 with the intermediate chamber 138 interposed therebetween, and the air chamber 120 includes the intermediate chamber 138 and the equilibrium chamber 136. It is formed between. The intermediate chamber 138 is filled with an incompressible fluid, like the pressure receiving chamber 134 and the equilibrium chamber 136.

  Further, as described above, the restraining arrangement region 58 is formed on the upper bottom portion of the upper partition member 36 constituting the partition wall partitioning the pressure receiving chamber 134 and the intermediate chamber 138, and the movable plate 62 is moved in the plate thickness direction (in FIG. 1). , Up and down) so as to be displaceable by a predetermined amount. Thus, in the present embodiment, the pressure receiving chamber 134 and the intermediate chamber 138 are partitioned by the lid member 56 and the movable plate 62 that form the restraint arrangement region 58 in addition to the upper partition member 36. The pressure in the pressure receiving chamber 134 and the intermediate chamber 138 is applied to the upper surface and the lower surface of the movable plate 62 through each of the plurality of through holes 60. When the vibration is input, the pressure receiving chamber 134 and the intermediate chamber 138 are applied. The pressure fluctuation in the pressure receiving chamber 134 is released to the intermediate chamber 138 based on the relative pressure difference fluctuation. Note that the amount of displacement of the movable plate 62 and the magnitude of the pressure fluctuation that is released from the pressure receiving chamber 134 to the intermediate chamber 138 is limited by the contact with the upper partition member 36 and the lid member 56. It will be limited based on. As is apparent from the above description, in this embodiment, the means for limiting the amount of fluid flow through the fluid flow path including the restraining arrangement region 58 and the plurality of through holes 60 includes the movable plate 62. Has been.

  Further, the lower opening of the outer opening 66 in which the check valve 70 is disposed in the lid member 56 is covered with the upper partition member 36, and the radially outward opening is the second mounting member 14. The valve body accommodating region 140 is formed between the pressure receiving chamber 134 and the intermediate chamber 138 by fluid-tightly covering the small diameter cylindrical portion 26 with the seal rubber layer 32 attached to the inner peripheral surface of the small diameter cylindrical portion 26 interposed therebetween. Is formed. The valve body accommodation region 140 is communicated with the pressure receiving chamber 134 through the flow path hole 68, and is communicated with the intermediate chamber 138 through the communication groove 50. The rubber valve body 72 of the check valve 70 is overlapped with the flow path hole 68 from the side opposite to the pressure receiving chamber 134, so that the flow path hole 68 is maintained in a closed state. While fluid flow from the chamber 134 to the intermediate chamber 138 is allowed, fluid flow from the intermediate chamber 138 to the pressure receiving chamber 134 is prevented.

  Therefore, a preload is set in the check valve 70 according to the present embodiment by the urging force of the metal plate spring 74, and the flow path hole 68 is maintained until the relative pressure of the pressure receiving chamber 134 with respect to the intermediate chamber 138 reaches a predetermined value. The closed state is maintained. In particular, in the present embodiment, when a small amplitude vibration such as a traveling boom noise is inputted, the flow path hole 68 is not opened, and the fluid flow from the pressure receiving chamber 134 to the intermediate chamber 138 is prevented, and an engine shake is performed. The preload is set such that fluid flow from the pressure receiving chamber 134 to the intermediate chamber 138 is allowed when large amplitude vibration is input.

  Further, the circumferential groove 44 of the upper partition member 36 is fluid-tightly covered with the small-diameter cylindrical portion 26 with the seal rubber layer 32 attached to the inner peripheral surface of the small-diameter cylindrical portion 26 of the second mounting bracket 14 interposed therebetween. Thus, an orifice passage 142 is formed. One end of the orifice passage 142 is connected to the pressure receiving chamber 134 through the communication window 46 of the upper partition member 36 and the through hole 143 of the lid member 56. The other end of the orifice passage 142 is connected to the equilibrium chamber 136 through the communication hole 48 of the upper partition member 36 and the communication passage 100 of the lower partition member 38. Thereby, the pressure receiving chamber 134 and the equilibrium chamber 136 are connected to each other by the orifice passage 142, and fluid flow through the orifice passage 142 is allowed between the chambers 134 and 136.

  In this embodiment, the anti-vibration effect is effective against vibrations in a low frequency range of around 10 Hz corresponding to an engine shake or the like based on the resonance action of the fluid flowing through the orifice passage 142. It is tuned so that (high attenuation effect) is exhibited. The orifice passage 142 can be tuned by, for example, the rigidity of the wall springs of the pressure receiving chamber 134 and the equilibrium chamber 136, that is, the main rubber elastic body 16 corresponding to the amount of pressure change required to change the fluid chamber by a unit volume. In consideration of the characteristic value based on each elastic deformation amount of the diaphragm 126 and the diaphragm 126, it is possible to adjust the passage length and the passage cross-sectional area of the orifice passage 142. Generally, the pressure fluctuation transmitted through the orifice passage 142 is changed. Can be grasped as the tuning frequency of the orifice passage 142.

  The engine mount 10 having such a structure is fixed to the power unit-side mounting member using a fixing bolt (not shown) in which the first mounting bracket 12 is screwed into the bolt hole 20, and the second mounting bracket. The 14 large-diameter cylindrical portion 24 and the like are fixed to an outer bracket (not shown), and the outer bracket is fixed to a mounting member on the vehicle body side with a bolt or the like. As a result, the engine mount 10 is mounted between the power unit and the vehicle body so that the power unit is supported on the vehicle body in a vibration-proof manner.

  In the engine mount 10 having such a structure, when a low-frequency large-amplitude vibration such as an engine shake is input, a large-amplitude pressure fluctuation is induced in the pressure receiving chamber 134. The movable plate 62 is displaced during the pressure fluctuation, but the movable distance of the movable plate 62 is set so that the pressure fluctuation in the pressure receiving chamber 134 is not easily absorbed by the displacement of the movable distance range in which the movable plate 62 is allowed. . Accordingly, the pressure absorbing action of the movable plate 62 cannot be substantially functioned.

  As a result, the positive pressure generated in the pressure receiving chamber 134 is applied to the check valve 70, and fluid flow from the pressure receiving chamber 134 to the intermediate chamber 138 through the check valve 70 is allowed. Particularly in this embodiment, since the intermediate chamber 138 is connected only to the pressure receiving chamber 134, the pressure exerted from the pressure receiving chamber 134 to the intermediate chamber 138 is not released to the equilibrium chamber 136. As a result, the movable rubber film 112 bulges and deforms as the positive pressure in the intermediate chamber 138 increases, and the volume of the intermediate chamber 138 is increased. Further, the movable rubber film 112 is brought close to the contact surface 106 along with the bulging deformation from the intermediate chamber 138. Here, fluid flow from the intermediate chamber 138 to the pressure receiving chamber 134 is blocked by the check valve 70, and the leak hole 90 has a low-frequency large-amplitude vibration such as an engine shake that exhibits the vibration-proofing effect by the orifice passage 142. Under the input state, a substantially closed state is assumed.

  As a result, the increase in the volume of the intermediate chamber 138 cannot be quickly eliminated in the input state of the low-frequency large-amplitude vibration, and the movable rubber film 112 receives the vibration input before returning to the initial state separated from the contact surface 106. As a result, the fluid is caused to further flow into the intermediate chamber 138, thereby being restrained while being brought close to the contact surface 106. In particular, in the present embodiment, the air chamber 120 is communicated with the external space through the air passage 108, so that the air chamber 120 is finally substantially disappeared and the movable rubber film 112 is brought into contact with the contact surface. 106 is constrained in a contact state. Further, particularly in the present embodiment, the movable rubber film 112 is inverted into a curved shape that is convex toward the contact surface 106, and the contact surface 106 is recessed to the opposite side of the movable rubber film 112. Therefore, the inverted movable rubber film 112 can be easily adhered to the contact surface 106 in a wide range, and can be restrained more firmly.

  As a result, the volume change of the intermediate chamber 138 is limited by increasing the rigidity of the wall spring of the movable rubber film 112, and the pressure fluctuation of the pressure receiving chamber 134 is suppressed from being absorbed by the intermediate chamber 138. Relative pressure fluctuations between 134 and equilibrium chamber 136 are effectively produced. Thereby, the flow amount of the fluid flowing through the orifice passage 142 can be effectively ensured, and the vibration isolation effect by the fluid action of the fluid flowing through the orifice passage 142 against the low frequency large amplitude vibration such as engine shake ( High attenuation effect) is effectively exhibited.

  On the other hand, when a high-frequency small-amplitude vibration such as a running-over sound is input, a pressure fluctuation with a small amplitude is caused in the pressure receiving chamber 134. The movable plate 62 is effectively displaced within the movable distance range when the pressure in the pressure receiving chamber 134 fluctuates, and the pressure fluctuation in the pressure receiving chamber 134 is transmitted to the intermediate chamber 138 due to the displacement of the movable distance range of the movable plate 62. . In particular, in the present embodiment, the leak hole 90 is substantially closed in the input state of such high-frequency small-amplitude vibration, and the check valve 70 is kept closed by preload. The pressure fluctuation is transmitted to the intermediate chamber 138 through the movable plate 62 more effectively.

  Under the input state of such high-frequency small-amplitude vibration, the orifice passage 142 tuned to a lower frequency range is substantially closed. As a result, the pressure receiving chamber 134 and the intermediate chamber 138 are both disconnected from the equilibrium chamber 136, but the movable rubber film 112 constituting a part of the wall portion of the intermediate chamber 138 is formed behind it. The air chamber 120 allows the elastic deformation to be relatively easily allowed. In particular, the movable rubber film 112 is set to have a spring characteristic that is soft enough to sufficiently absorb pressure fluctuations in the intermediate chamber 138 caused by the input of high-frequency small-amplitude vibration such as running-over noise. ing. Therefore, the intermediate chamber 138 exhibits a hydraulic pressure absorption action based on the elastic deformation of the movable rubber film 112, and the pressure fluctuation in the pressure receiving chamber 134 is absorbed by the intermediate chamber 138. Therefore, a remarkable high dynamic spring due to the general blockage is avoided, and a good anti-vibration effect (vibration insulation effect based on low dynamic spring characteristics) against high frequency small amplitude vibration is exhibited. In particular, in this embodiment, since the air chamber 120 is opened to the atmosphere through the air passage 108, the elastic deformation of the movable rubber film 112 is more easily permitted, and a more excellent hydraulic pressure absorbing effect is exhibited. To be able to be.

  When the input of low-frequency large-amplitude vibration such as engine shake or high-frequency small-amplitude vibration such as running noise is eliminated, fluid flow between the pressure receiving chamber 134 and the intermediate chamber 138 through the leak hole 90 is allowed. Is done. Thereby, when a static pressure exists between the pressure receiving chamber 134 and the intermediate chamber 138, the static pressure is gradually recovered by the fluid flow through the leak hole 90.

  As described above, according to the present embodiment, all of the vibrations in a plurality of different frequency ranges are effective with a simple configuration without providing an actuator that requires supply of external energy such as air pressure or electric power. Can exhibit excellent anti-vibration effect.

  In particular, in the present embodiment, the vibration isolation switching structure including the check valve 70 and the leak hole 90 is provided in the fluid chamber 132 that is cut off from the external space. The influence of dust from the outside can also be avoided, and better operational stability and durability can be obtained.

  Furthermore, particularly in the present embodiment, since the movable rubber film 112 has a substantially dome shape that protrudes toward the intermediate chamber 138 under static pressure, the convex shape in the state where the air chamber 120 exists is The shape of the air chamber 120 can be clearly changed to the concave shape in a state where the air chamber 120 has disappeared, and the vibration isolation effect by the orifice passage 142 and the vibration isolation effect by the movable plate 62 are more reliably and highly reliable. Can be switched under certain conditions.

  As mentioned above, although one Embodiment of this invention was explained in full detail, this is an illustration to the last, Comprising: This invention is not limited at all by the specific description in this Embodiment. In the following description, members and parts that are substantially the same as those of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment, and detailed description thereof is omitted.

  For example, the leak hole 90 in the above embodiment is not necessarily required, and instead of the leak hole 90, the passage length, the cross-sectional area, the shape, etc. of the through hole 60 that communicates the pressure receiving chamber 134 and the intermediate chamber 138 in the partition member 34 are adjusted. By doing so, the through hole 60 may be used as a static pressure recovery hole.

  Further, by adjusting the passage length and the cross-sectional area of the through hole 60 in the above embodiment, the through hole 60 is tuned to a frequency range different from the tuning frequency range of the orifice passage 142 formed on the outer periphery of the partition member 34. A configured fluid flow path may be configured. For example, the passage length and the cross-sectional area of the through hole 60 in the above-described embodiment are determined with respect to the vibration in the high frequency range of about 130 Hz corresponding to the traveling boom noise in the high frequency range than the engine shake with the orifice passage 142 tuned. You may tune so that an effective anti-vibration effect (low dynamic spring effect) may be exhibited. In this way, at the time of vibration input in a high frequency range such as traveling noise, fluid flow through the through hole 60 is generated based on the displacement of the movable plate 62, and the resonance of the fluid that causes the through hole 60 to flow. An anti-vibration effect (low dynamic spring effect) based on the effect can be exhibited.

  Then, by adjusting the passage length and the cross-sectional area of the through hole 60, the fluid flow path constituted by the through hole 60 can be tuned. For example, as illustrated in FIG. Can be tuned to exhibit an effective anti-vibration effect (low dynamic spring effect) against vibration in the middle frequency range of 20 to 40 Hz corresponding to idling vibration, for example. .

  Further, the movable plate 62 in FIG. 3 has a substantially disc shape formed of a rubber elastic body, and is axially moved in the restraint arrangement region 58 formed in the partition member 34 (vertical direction in FIG. 3). It is arranged to be displaceable. Thus, the specific structure of the pressure fluctuation transmission member is not particularly limited. For example, as exemplified in FIG. 4, a movable film 144 may be used instead of the movable plate 62. The movable film 144 has a thin and substantially disk shape formed using a rubber elastic body, and an annular elastic protrusion protruding on both sides in the axial direction (vertical direction in FIG. 4) on the outer peripheral edge thereof. The part 146 is integrally formed. Then, the movable film 144 is disposed in the constraining region 58 of the partition member 34 such that the elastic protrusion 146 of the movable film 144 is sandwiched between the lid member 56 and the upper partition member 36.

  Even in this case, based on the elastic deformation of the movable film 144, it is possible to absorb minute pressure fluctuations in the pressure receiving chamber 134 when a high frequency small amplitude vibration is input. In FIG. 4, the cover member 56 and the upper partition member 36 are disposed on both sides of the movable film 144 in the axial direction, respectively, so that excessive deformation of the movable film 144 is limited. Of course, it is possible to remove the lid members 56 and the upper partition member 36 on both sides in the axial direction so as not to limit the deformation amount of the movable film 144.

  Various known structures can be appropriately employed as the one-way valve. For example, FIGS. 5 to 8 exemplarily illustrate check valves 150, 152, 154, and 155 as one-way valves of different modes. The check valve 150 exemplarily shown in FIG. 5 is formed of a metal ball or the like in a valve body accommodating region 140 formed between the upper bottom portion 67 of the lid member 56 and the upper end surface of the upper partition member 36. The spherical valve body 156 is disposed in the accommodated state, and a coil spring 158 is interposed in a compressed state between the spherical valve body 156 and the upper end surface of the upper partition member 36. Thereby, the spherical valve body 156 is urged toward the upper bottom portion 67 by the coil spring 158 and is pressed from below onto the flow passage hole 68 penetrating the upper bottom portion 67, thereby closing the flow passage hole 68. It is supposed to hold on. In the check valve 150, the preload is set by the biasing force of the coil spring 158.

  In addition, the check valve 152 exemplified in FIG. 6 includes a rubber valve body 160 instead of the spherical valve body 156 in the check valve 150. The rubber valve body 160 is made of a metal plate or the like on one surface in the axial direction (vertical direction in FIG. 6) of the rubber elastic plate 162 having a substantially disk shape having a larger outer diameter than the flow path hole 68. The shape holding plate 164 is provided. The coil spring 158 is interposed in a compressed state between the rubber valve body 160 and the upper end surface of the upper partition member 36 with the shape retaining plate 164 interposed between the rubber elastic plate 162 and the coil spring 158. It has been. As a result, the rubber elastic plate 162 of the rubber valve body 160 is pressed against the flow path hole 68 from below to hold the flow path hole 68 in a closed state, and the preload is set by the biasing force of the coil spring 158.

  In addition, the check valve 154 illustrated as a model in FIG. 7 has a disk-shaped rubber valve body 166 having an outer diameter larger than that of the flow path hole 68 overlapped from below the flow path hole 68 and a rubber valve body. A part of the outer peripheral portion of 166 is fixed to the lower surface of the upper bottom portion 67 by adhesion or the like. In the check valve 154, the flow path hole 68 is maintained in a closed state by the elastic force of the rubber valve body 166 itself, and the preload is set by the elastic force of the rubber valve body 166 itself.

  Further, the check valve 155 exemplarily illustrated in FIG. 8 is integrally formed with the movable film 144 illustrated in FIG. In FIG. 8, the partition member 34 is removed from the partition member 34 including the annular protrusion 54 that partitions the restraining arrangement region 58 and the valve element housing region 140, and the positioning protrusion that positions the elastic protrusion 146 of the movable film 144. 168 is formed projecting toward the other on the opposing surfaces of the upper partition member 36 and the lid member 56. Further, the elastic protrusion 146 is positioned by the positioning protrusion 168 and is sandwiched between the upper partition member 36 and the lid member 56 from both sides in the axial direction, whereby the restraining arrangement region 58 and the valve element housing region 140 are separated by the elastic protrusion 146. A compartment is formed.

  A rubber valve body 170 is integrally formed to protrude from an elastic protrusion 146 that constitutes a part of the wall portion of the valve body housing region 140. The rubber valve body 170 has a protruding piece shape that protrudes radially outward at the upper end of the elastic protrusion 146, and its thickness dimension increases from the elastic protrusion 146 toward the radially outward direction. Is gradually reduced.

  The rubber valve body 170 having such a shape is superimposed on the flow path hole 68 from below the flow path hole 68 in a state in which the movable membrane 144 is assembled to the upper partition member 36 and the lid member 56. Yes. Thereby, the flow path hole 68 is maintained in the closed state by the elastic force of the rubber valve body 170, and the preload is set by the elastic force of the rubber valve body 170 itself. In this way, the number of parts can be further reduced, and the pressure fluctuation transmission member and the one-way valve can be assembled at the same time, so that the number of manufacturing steps can be further reduced.

  In the above embodiment, a preload is set for the one-way valve, and fluid flow from the pressure-receiving chamber to the intermediate chamber through the one-way valve is prevented when high-frequency small-amplitude vibration such as traveling noise is input. The fluid flow through the one-way valve may be allowed when high-frequency small-amplitude vibration is input. In such a case, the fluid flow resistance of the static pressure recovery hole may allow a flow amount that can recover the volume increase of the intermediate chamber due to the fluid flow through the one-way valve when high-frequency small-amplitude vibration is input. It is preferable to set to.

  Furthermore, the air opening hole that communicates the air chamber with the external space is not always necessary, and the air chamber may be sealed from the external space. In such a case, at the time of vibration input in the tuning frequency range of the orifice passage, the amount of deformation of the elastic partition increases due to the increase in the volume of the intermediate chamber. This contributes to an increase in the rigidity of the wall spring of the chamber and suppresses the escape of pressure from the pressure receiving chamber to the intermediate chamber by the hydraulic pressure absorbing mechanism configured to include the pressure fluctuation transmitting member.

  Needless to say, the specific shapes of the first mounting member, the second mounting member, and the main rubber elastic body connecting them are not limited at all. For example, Japanese Patent Laid-Open No. 2005-23972 As described in the official gazette and the like, the contact fitting is axially spaced from the second attachment member, and the second attachment member and the contact fitting are connected by the main rubber elastic body. The first mounting member may be separated from the main rubber elastic body in the rebound direction by bringing the first mounting member into contact with the contact metal fitting. In this way, when the first mounting member and the second mounting member are excessively separated from each other, the first mounting member is separated from the main rubber elastic body. The possibility that pressure is generated can be reduced. Thereby, generation | occurrence | production of cavitation can be suppressed and generation | occurrence | production of the abnormal sound considered that it originates in cavitation and a vibration can be suppressed.

  Furthermore, in the above-described embodiments, specific examples of the present invention applied to an automobile engine mount have been described. However, the present invention is not limited to an automobile body mount, a differential mount, or the like, but is also an anti-vibration mount for various vibrating bodies other than an automobile. However, it goes without saying that both are applicable.

The longitudinal section explanatory view of the engine mount as one embodiment of the present invention. The longitudinal cross-sectional explanatory drawing for demonstrating the one way valve provided in the engine mount. The longitudinal cross-sectional explanatory drawing for demonstrating the aspect from which a fluid flow path differs. The longitudinal cross-sectional explanatory drawing for demonstrating the different aspect of a pressure fluctuation transmission member. The longitudinal cross-sectional explanatory drawing for demonstrating the different aspect of a one-way valve. The longitudinal cross-sectional explanatory drawing for demonstrating the further different aspect of a one-way valve. The longitudinal cross-sectional explanatory drawing for demonstrating the further different aspect of a one-way valve. The longitudinal cross-sectional explanatory drawing for demonstrating the further different aspect of a one-way valve.

Explanation of symbols

10: engine mount, 12: first mounting bracket, 14: second mounting bracket, 16: main rubber elastic body, 58: restraint arrangement region, 62: movable plate, 70: check valve, 90: leak hole, 112: movable rubber film, 120: air chamber, 126: diaphragm, 134: pressure receiving chamber, 136: equilibrium chamber, 138: intermediate chamber, 142: orifice passage

Claims (6)

A first attachment member attached to one member to be vibration-proof connected;
A second attachment member attached to the other member to be vibration-proof connected;
A main rubber elastic body for elastically connecting the first mounting member and the second mounting member;
A pressure receiving chamber in which a part of the wall portion is constituted by the main rubber elastic body so that pressure fluctuation is caused at the time of vibration input and in which an incompressible fluid is sealed;
An equilibrium chamber in which a part of the wall portion is made of a flexible film and has a variable volume, and an incompressible fluid is enclosed,
An intermediate chamber in which a part of the wall portion is composed of an elastic partition wall and in which an incompressible fluid is enclosed;
An air chamber formed on the opposite side of the intermediate chamber across the elastic partition;
An orifice passage communicating the pressure receiving chamber and the equilibrium chamber;
A pressure fluctuation transmitting member that is disposed between the pressure receiving chamber and the intermediate chamber and transmits a pressure fluctuation of the pressure receiving chamber to the intermediate chamber by allowing a predetermined amount of displacement;
A one-way valve that allows fluid flow from the pressure receiving chamber to the intermediate chamber but prevents fluid flow from the intermediate chamber to the pressure receiving chamber;
In order to recover the increase in volume of the intermediate chamber due to fluid flow from the pressure receiving chamber to the intermediate chamber through the one-way valve in the input state of tuning vibration of the orifice passage through the pressure receiving chamber and the intermediate chamber. Only an insufficient fluid flow amount is allowed, and in a non-input state of tuning vibration of the orifice passage, a fluid flow amount sufficient to restore the initial volume of the intermediate chamber is allowed based on the elasticity of the elastic partition. A fluid-filled vibration isolator comprising a static pressure recovery hole in which fluid flow resistance is set.   An air opening hole for communicating the air chamber with the atmosphere is provided, and an inner surface of the air chamber facing the elastic partition wall is input to the pressure passage through the one-way valve in an input state of tuning vibration of the orifice passage. 2. The fluid filled type vibration damping device according to claim 1, wherein at least a part of the elastic partition wall is brought into contact with an increase in volume of the intermediate chamber accompanying fluid flow from the intermediate chamber to the intermediate chamber.   The elastic partition that defines the air chamber has a curved convex shape that swells in a substantially dome shape toward the intermediate chamber, and an opposing inner surface of the air chamber that faces the elastic partition includes the elastic partition and The fluid-filled vibration isolator according to claim 2, wherein the fluid-filled vibration isolator has a curved concave shape that is recessed toward the opposite side.   The fluid according to any one of claims 1 to 3, wherein a preload is set in the one-way valve to maintain a closed state until a relative positive pressure of the pressure receiving chamber with respect to the intermediate chamber reaches a predetermined value. Enclosed vibration isolator.   5. The fluid flow path in which fluid flow is generated based on the displacement of the pressure fluctuation transmission member is formed, and the fluid flow path is tuned to a higher frequency range than the orifice passage. The fluid-filled vibration isolator according to claim 1.   The second mounting member includes a cylindrical portion, the first mounting member is disposed on one opening side of the cylindrical portion, and the first mounting member and the second mounting member are arranged. One side of the cylindrical portion is closed by the main rubber elastic body to be connected, while the other opening of the cylindrical portion is closed by the flexible film. An incompressible fluid sealing region is formed between the opposing surfaces of the flexible film and the flexible membrane, and a partition member is disposed between the opposing surfaces of the main rubber elastic body and the flexible membrane. The pressure receiving chamber is formed between the partition member and the main rubber elastic body, and the equilibrium chamber is formed between the partition member and the flexible membrane. Further, the intermediate chamber and the air chamber are formed inside the partition member. Fluid filled type vibration damping device.

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