JP2005233242A - Pneumatic switch-over type fluid-filled engine mount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid-filled engine mount of new structure capable of showing high-degree vibration control performance in relation to any of four kinds of vibration of low-frequency large-amplitude vibration, low-frequency small-amplitude vibration, high-frequency fine-amplitude vibration and middle-frequency middle-amplitude vibration. <P>SOLUTION: A second orifice passage 102 is controlled to open/close by a pneumatic actuator 106, and on the other hand, a central movable plate 92 as a movable plate is arranged in a central part of a movable partition member 64, and a peripheral movable rubber film part 84 as a movable film is arranged in the peripheral part. The central movable plate 92 and the peripheral movable rubber film part 84 can be sucked to be constrained by external negative pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine mount for supporting a power unit on a vehicle body in a vibration-proof manner in an automobile, and in particular, using a flow action of an incompressible fluid sealed inside, a plurality of or shakes such as an engine shake and idling vibration. The present invention relates to a fluid-filled engine mount that can exhibit an effective vibration-proofing effect against vibrations in a wide frequency range.

  Conventionally, as a kind of automobile engine mount, a first attachment member and a second attachment member attached to one of a power unit and a vehicle body are connected by a main rubber elastic body, and the main rubber elastic body is used as a wall. Forming a pressure receiving chamber in which a part of the part is configured, and an equilibrium chamber in which a part of the wall is configured by a flexible membrane, enclosing the incompressible fluid in the pressure receiving chamber and the equilibrium chamber, and receiving the pressure 2. Description of the Related Art A fluid-filled engine mount having an orifice passage that communicates a chamber and an equilibrium chamber with each other is known.

  By the way, in the engine mount for automobiles, the frequency of vibrations to be vibrated differs depending on the running state of the automobile. However, the anti-vibration effect exhibited based on the resonance action of the fluid flowing through the orifice passage is limited to a relatively narrow frequency range in which the orifice passage is tuned in advance. Therefore, the applicant previously provided a first and second orifice passages tuned to different frequency ranges in Patent Document 1 (Japanese Patent Application Laid-Open No. 8-270718) and tuned to a higher frequency range. An engine that has an on-off valve that switches the second and second orifice passages between the communication state and the shut-off state, and selectively operates the two orifice passages according to the vibration to be vibration-isolated to switch the mount vibration-isolation characteristics. Proposed mount.

  However, in recent years, since a higher level of anti-vibration performance has been demanded, even the engine mount described in Patent Document 1 may not yet achieve the required anti-vibration performance. One of the required characteristics is anti-vibration performance against high-frequency vibrations such as traveling booming noise, which is a problem during traveling. Another required characteristic is anti-vibration performance against low-frequency vibration such as engine shake, which becomes a problem during running. Furthermore, the latter low-frequency vibrations are required to have anti-vibration performance against two types of vibrations: low-frequency large-amplitude vibrations that are problematic when climbing over steps, and low-frequency small-amplitude vibrations that are problematic during normal driving. .

  First, in order to deal with the required characteristics of the former (anti-vibration performance against high-frequency vibration), attention is paid to the fact that the vibration which is a problem in the high frequency range is generally a small amplitude. As described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2001-200884), a movable film made of a thin rubber film is arranged in a partition wall partitioning the pressure receiving chamber and the equilibrium chamber to tune two orifice passages. It is conceivable to reduce the dynamic spring by absorbing the pressure fluctuation in the pressure receiving chamber at the time of vibration input in a high frequency range exceeding the frequency by elastic deformation of the movable film.

  However, when such a movable film is used, there is a risk that the pressure fluctuation in the pressure receiving chamber may be absorbed by the movable film until the input of small amplitude vibrations in the low frequency range, thereby tuning to the low frequency range. There is a problem that it is difficult to ensure a sufficient amount of fluid flow through the first orifice passage, and it is difficult to exhibit a sufficient damping action against low-frequency small-amplitude vibration. In addition, since it is difficult to limit the amount of elastic deformation of a movable film made of a thin rubber film, the pressure variation in the pressure receiving chamber is caused by the elastic deformation of the movable film even when idling vibration of medium amplitude is input. As a result, the fluid flow amount through the second orifice passage tuned to the middle frequency range is difficult to be secured, and the anti-vibration performance against idling vibration is reduced.

  Instead of a movable film made of a rubber film, for example, as described in Patent Document 3 (Japanese Utility Model Laid-Open No. 2-25749), a hard movable plate is displaced by a minute distance in a partition wall partitioning the pressure receiving chamber and the equilibrium chamber. Although it may be possible to dispose the hard movable plate, it is necessary to provide a small gap on the outer peripheral side in order to allow the minute displacement, and pressure leaks from the pressure receiving chamber to the equilibrium chamber through this minute gap. Is likely to occur. For this reason, as with the rubber film, the pressure fluctuation in the pressure receiving chamber at the time of vibration input of low frequency small amplitude vibration and medium frequency medium amplitude leaks, and the amount of fluid flow through the first and second orifice passages is sufficient. There is a problem that it is difficult to ensure, and the anti-vibration performance against low amplitude components of engine shake and idling vibration is deteriorated.

JP-A-8-270718 Japanese Patent Laid-Open No. 2001-2000884 Japanese Utility Model Publication No. 2-025749

Here, the present invention has been made in the background as described above, and the problem to be solved is that for any of the following four types of vibration required in an engine mount of an automobile, It is an object of the present invention to provide a fluid-filled engine mount having a novel structure that can realize high vibration-proof performance.
(1) Excellent anti-vibration performance based on high damping characteristics against low-frequency large-amplitude vibration corresponding to engine shake, etc. generated when stepping over steps (2) Low-frequency small-amplitude vibration corresponding to engine shake, etc., generated during normal driving Excellent anti-vibration performance based on high damping characteristics (3) Excellent anti-vibration performance based on low dynamic spring characteristics against high-frequency micro-amplitude vibration equivalent to running-over noise generated during traveling (4) Idling vibration generated when stopped Anti-vibration performance based on low dynamic spring characteristics against medium-frequency medium-amplitude vibration equivalent to

  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 features of the present invention are: (a) a first attachment member attached to one of the power unit side member and the vehicle body side member; and (b) the other of the power unit side member and the vehicle body side member. A second mounting member to be mounted; (c) a main rubber elastic body that elastically connects the first mounting member and the second mounting member; and (d) one of the wall portions by the main rubber elastic body. A pressure receiving chamber in which an incompressible fluid is enclosed, (e) an equilibrium chamber in which a part of the wall portion is formed of a flexible film and volume change is allowed, and (f) the pressure receiving chamber And a first orifice passage tuned to a low frequency region substantially corresponding to an engine shake, and (g) a communication between the pressure receiving chamber and the equilibrium chamber, which is substantially free from idling vibration. In the corresponding middle frequency range A tuned second orifice passage; (h) valve means for communicating / blocking the second orifice passage; and (i) a pneumatic actuator that is actuated by air pressure exerted from outside to drive the valve means. And (j) the central portion is a rigid central movable plate portion, and the outer peripheral portion is an easily movable outer peripheral movable rubber film portion. A movable partition member arranged to allow a certain amount of displacement or deformation, and constituting another part of the wall portion of the pressure receiving chamber; (k) the pressure receiving chamber sandwiching the movable partition member; The air pressure switching type fluid-filled engine mount has a working air chamber formed on the opposite side and capable of adjusting air pressure from the outside.

In such a fluid-filled engine mount having a structure according to the present invention, the following vibration isolation characteristics will be exhibited according to the difference in the frequency and amplitude of vibration to be input that is to be isolated. Therefore, an effective anti-vibration effect can be exhibited against these various different vibrations.
(1) With respect to low-frequency large-amplitude vibration corresponding to engine shake or the like that occurs when stepping over a step, fluid pressure absorption due to displacement or deformation of the movable partition member composed of the central movable plate portion and the outer peripheral movable rubber film portion follows. However, effective pressure fluctuation can be caused in the pressure receiving chamber. Thereby, a relative pressure variation is effectively generated between the pressure receiving chamber and the equilibrium chamber. Therefore, if the second orifice passage is maintained in the shut-off state by the valve means, the amount of fluid flow through the first orifice passage can be advantageously ensured, and the resonance of the fluid flowing through the first orifice passage can be ensured. A high damping effect based on the action is exhibited, and an excellent anti-vibration performance can be realized.
(2) For low-frequency, small-amplitude vibration corresponding to engine shake or the like that occurs during normal running, there is concern about the pressure absorption of the pressure receiving chamber by the movable partition member, but the fluid tightness on the outer peripheral side of the central movable plate portion Is ensured by the outer peripheral movable rubber film part, and the central movable plate part is made hard so that the deformation amount of the movable partition member is suppressed, so that the pressure receiving chamber is still sufficiently effective pressure. Variation will be induced. Therefore, as in the case of the low-frequency large-amplitude vibration described above, if the second orifice passage is maintained in the shut-off state by the valve means, the amount of fluid flow through the first orifice passage can be advantageously ensured, A high damping effect based on the resonance action of the fluid flowing through the first orifice passage is exhibited, and an excellent vibration isolation performance can be realized.
(3) The pressure fluctuation in the pressure receiving chamber is very small with respect to the high-frequency minute amplitude vibration corresponding to the traveling noise generated during the running, and therefore the pressure fluctuation in the pressure receiving chamber is caused by the displacement or deformation of the movable partition member. It can be effectively absorbed or reduced. In particular, the central movable plate portion of the movable partition member is formed in the central portion to advantageously ensure an effective area, and the outer peripheral movable rubber film portion that supports the outer peripheral edge thereof in a fluid-tight manner is easily deformed. Therefore, it is possible to advantageously follow and displace the pressure fluctuation in the high frequency region in the pressure receiving chamber, and the pressure fluctuation in the pressure receiving chamber can be suppressed. Therefore, at the time of vibration input in a high frequency range, significant pressure fluctuations in the pressure receiving chamber can be avoided by the movable partition member even in a state where the first and second orifice passages are substantially closed. Excellent vibration isolation performance can be exhibited by an effective vibration insulation action based on the dynamic spring characteristics.
(4) For medium-frequency medium-amplitude vibration corresponding to idling vibration or the like generated when the vehicle is stopped, the pneumatic actuator is operated to bring the second orifice passage into communication, and air pressure ( A negative pressure or a positive pressure) is applied to exert a restraining force on the central movable plate portion and the outer peripheral movable rubber film portion. As a result, pressure absorption by the movable partition member is prevented, and effective pressure fluctuation is induced in the pressure receiving chamber, and the amount of fluid flow that is allowed to flow through the second orifice passage between the pressure receiving chamber and the equilibrium chamber is advantageous. It can be ensured, and excellent vibration isolation performance is exhibited based on the resonance action of the fluid. Although the first orifice passage is also in communication, it is substantially closed due to the anti-resonant action of the flowing fluid with respect to medium frequency input vibrations in the frequency range exceeding the tuning frequency. .

  In the present invention, it is preferable that an elastic abutting protrusion protrudes from the outer peripheral edge portion of the central movable plate portion of the movable partition member and is supported by the second attachment member or the second attachment member. Displacement amount limiting means for limiting the displacement amount of the central movable plate portion in a buffering manner is provided by bringing the elastic contact protrusion into contact with the displacement regulating member.

  By providing such a displacement amount limiting means, it is possible to more effectively suppress the pressure fluctuation in the pressure receiving chamber from being absorbed by the movable partition member at the time of inputting low frequency large amplitude vibration as well as low frequency large amplitude vibration. It becomes possible. Further, the amount of fluid flowing through the first orifice passage is increased to further improve the damping effect based on the resonance action of the fluid, and to further improve the anti-vibration performance against low-frequency vibration associated therewith. Can be illustrated. Further, since the support spring characteristic of the central movable plate part can be adjusted by the contact of the elastic contact protrusion with the displacement restricting member, the traveling vibration noise can be adjusted by adjusting the natural frequency of the central movable plate part. By adjusting to the vibration frequency range of the high frequency equivalent to, etc., it is possible to further improve the vibration isolation performance based on the pressure absorption of the pressure receiving chamber in the high frequency range by utilizing the resonance action of the central movable plate part. It becomes. The displacement restricting member with which the elastic contact protrusion is brought into contact can be advantageously configured, for example, by being fixedly supported by the second attachment member, specifically, by the second attachment member. The displacement regulating member can be advantageously configured by using a partition member that is fixedly supported and forms a partition that partitions the pressure receiving chamber and the equilibrium chamber.

  In the present invention, preferably, in the pneumatic actuator, the valve means is driven so that the second orifice passage is shut off when a substantially atmospheric pressure is applied from the outside, while the negative pressure is externally applied. The valve means is driven so that the second orifice passage is in communication with the pressure.

  By adopting such a configuration of the pneumatic actuator and the valve means, it becomes possible to skillfully use the negative pressure that can be easily obtained from the intake system of the internal combustion engine, particularly in an automobile. In particular, since the negative pressure increases toward the negative pressure side in the idling state, the valve means can be driven in the idling state by using the large negative pressure to bring the second orifice passage into the communication state.

  Further, in the present invention, preferably, the working air chamber and the pneumatic actuator exert a negative pressure when the automobile is stopped, while exerting a substantially atmospheric pressure when the automobile is in a running state. It is characterized in that air pressure control means for controlling the air pressure exerted on the air chamber and the pneumatic actuator in conjunction with each other is provided.

  By adopting such air pressure control means, it is possible to easily realize supply and discharge of air pressure to and from the working air chamber and the pneumatic actuator in a simple control mode. Further, as described above, the negative pressure generated in the internal combustion engine of the automobile can be used more skillfully.

  In the present invention, it is preferable that a hard restraint plate is disposed on the central movable plate portion of the movable partition member, and the outer peripheral movable rubber film portion is bonded to the outer peripheral edge portion of the restraint plate. Is adopted.

  By adopting such a restraint plate, absorption of pressure fluctuations in the pressure receiving chamber at the time of vibration input in the low to medium frequency range due to unnecessary deformation in the central movable plate portion can be more reliably suppressed, As a result, the target vibration isolation effect based on the resonance action of the fluid flowing through the first orifice passage and the second orifice passage can be more effectively and stably exhibited. In addition, as a restraint plate, the thin board | plate material which consists of hard synthetic resin material, a metal, etc. is employ | adopted suitably. Further, the central movable plate portion can be constituted by only the restraining plate, and can be constituted by adhering the outer peripheral movable rubber film portion to the outer peripheral edge portion thereof, or, for example, substantially the central movable plate portion. A restraint plate is bonded to the central portion of the rubber elastic film that extends over the entire surface to form a central movable plate portion at the central portion of the rubber elastic film, and the outer peripheral movable rubber film is formed by the outer peripheral edge of the rubber elastic film. A part may be formed.

  In the present invention, preferably, when the input vibration exerted between the first mounting member and the second mounting member is a minute amplitude vibration of ± 0.05 mm or less, the pressure receiving chamber is caused. Although the pressure fluctuation can be substantially absorbed, the input vibration exerted between the first mounting member and the second mounting member is small amplitude vibration around ± 0.1 mm or large amplitude over ± 1.0 mm. In the case of vibration, the displacement or deformation characteristics of the movable partition member are set so that pressure fluctuations induced in the pressure receiving chamber cannot be substantially absorbed.

  In this embodiment, although it differs depending on the vehicle type, etc., it is generally a problem in many automobiles. (1) In the low frequency range around 10 Hz, it is made to act as a large amplitude vibration around ± 1.0 mm. Low-frequency large-amplitude vibration such as engine shake caused by overstepping, etc., and (2) Engine-shaking that causes problems during normal driving, which is caused as small-amplitude vibration around ± 0.1 mm in a low-frequency range around 10 Hz. (3) In the high frequency range from 50Hz to several hundreds Hz, it can be operated as a small amplitude vibration of ± 0.05mm or less. In addition, all of the excellent vibration-proof performances due to the low dynamic spring action against high-frequency vibrations such as a booming noise that becomes a problem during traveling can be realized more effectively.

  As is apparent from the above description, in the pneumatic switching type fluid-filled engine mount having the structure according to the present invention, the first and second orifice passages and the movable partition member are separated from each other by the vibration frequency to be damped. Each of them functions efficiently according to the amplitude, (1) low-frequency large-amplitude vibration corresponding to an engine shake associated with stepping over a step, and (2) low-frequency small amplitude corresponding to an engine shake during normal driving. Effective vibration isolation for vibration, (3) high-frequency micro-amplitude vibration corresponding to a booming sound during driving, and (4) medium-frequency medium-amplitude vibration corresponding to idling vibration when stopped, etc. An effect can be obtained.

  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 a vibration isolating mount 10 for an automobile as an embodiment of the present invention. This anti-vibration mount 10 has a structure in which a first mounting member 12 as a first mounting member and a second mounting member 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 body side of the automobile via the bracket 18 to support the power unit against vibration against the body. It is like that. In the following description, the vertical direction basically means the vertical direction in FIG.

  More specifically, the first mounting bracket 12 has a substantially inverted truncated cone block shape. A mounting bolt 20 is integrally formed on the end surface on the large diameter side so as to protrude upward in the axial direction.

  On the other hand, the second mounting bracket 14 has a substantially cylindrical shape with a large diameter as a whole. In addition, the second mounting bracket 14 includes a constricted portion 22 at the upper end in the axial direction. The constricted portion 22 is recessed inward in the radial direction and extends to the entire circumference in the circumferential direction, and by the constricted portion 22, the axially upper opening portion of the second mounting bracket 14 gradually expands upward. Inverted taper shape.

  In the second mounting bracket 14 having such a structure, the first mounting bracket 12 is disposed on substantially the same central axis so as to be separated from the upper opening side. A main rubber elastic body 16 is disposed between the first mounting bracket 12 and the second mounting bracket 14, and the first mounting bracket 12 and the second mounting bracket are arranged by the main rubber elastic body 16. 14 are elastically connected.

  The main rubber elastic body 16 has a truncated cone shape as a whole, and is vulcanized and bonded to the main rubber elastic body 16 so that the first mounting member 12 is inserted from the end surface on the small diameter side. Further, the opening portion on the upper side in the axial direction of the second mounting bracket 14 is overlapped and vulcanized and bonded to the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16. As a result, the tapered outer peripheral surface of the first mounting bracket 12 and the reverse tapered inner peripheral surface of the constricted portion 22 of the second mounting bracket 14 are positioned to face each other, and the main rubber is interposed between the opposing surfaces. An elastic body 16 is interposed. In this embodiment, the main rubber elastic body 16 is an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14.

  Further, the opening of the second mounting bracket 14 is vulcanized and bonded to the outer peripheral surface of the main rubber elastic body 16 in this manner, so that the opening on the axial direction upper side of the second mounting metal 14 is the main rubber elastic body. 16 is closed fluid-tightly. A mortar-shaped large-diameter recess 24 is formed on the large-diameter side end surface of the main rubber elastic body 16 and is opened in the second mounting bracket 14.

  Furthermore, a seal rubber layer 26 is formed on the inner peripheral surface of the second mounting bracket 14. The seal rubber layer 26 is integrally formed with the main rubber elastic body 16, and the inner peripheral surface of the second mounting member 14 is covered with the seal rubber layer 26 over substantially the entire surface.

  Furthermore, a partition member 28 and a rubber diaphragm 30 as a flexible film are sequentially fitted into the second mounting bracket 14 from an opening portion below the axial direction thereof. And fixed. A cylindrical fixed tube fitting 32 is vulcanized and bonded to the outer peripheral edge of the rubber diaphragm 30, and the fixed tube fitting 32 is fitted and fixed to the lower end opening of the second mounting bracket 14. Thus, the lower end opening of the second mounting member 14 is covered fluid-tightly.

  Accordingly, a pressure receiving chamber 34 in which a part of the wall portion is configured by the main rubber elastic body 16 is formed on the upper side in the axial direction of the partition member 28, while the wall on the lower side in the axial direction of the partition member 28 is formed. An equilibrium chamber 36 is formed, part of which is made of a rubber diaphragm 30. The pressure receiving chamber 34 and the equilibrium chamber 36 are fluid-tightly partitioned with respect to the external space, and incompressible fluids such as water, alkylene glycol, polyalkylene glycol, and silicone oil are sealed therein, respectively.

  In the pressure receiving chamber 34, a positive pressure fluctuation is generated based on the elastic deformation of the main rubber elastic body 16 at the time of vibration input. On the other hand, in the equilibrium chamber 36, the deformation of the rubber diaphragm 30 is easily allowed and the volume is variable, so that the pressure fluctuation is quickly absorbed.

  Here, the partition member 28 includes a partition block 38 having a thick, substantially disk shape, as shown in FIGS. In the partition block 38, an upper central recess 40 and a lower central recess 42 are formed with a substantially circular concave shape at the respective center portions of the upper end surface and the lower end surface.

  In addition, the partition block 38 is formed with a circumferential groove 44 that opens to the outer peripheral surface and extends by bending in the circumferential direction, and both ends of the circumferential groove 44 are formed on one axial surface. Opened. Furthermore, the partition block 38 is formed with an axial groove 46 that opens to the outer peripheral surface and extends linearly at a predetermined length in the axial direction, and the upper end of the axial groove 46 is circumferentially recessed. One end of the groove 44 is used to open the upper surface of the partition member 28, and the lower end thereof is connected to the lower central recess 42 through a communication hole 48 that is tunnel-shaped and extends in the radial direction.

  Furthermore, the upper central recess 40 of the partition block 38 is provided with a stepped surface 50 at the intermediate portion in the depth direction, and a stepped circular recess comprising a small-diameter recess 52 on the bottom side and a large-diameter recess 54 on the opening side. Has been. Further, the step surface 50 is formed with a groove-like annular recess 56 continuously extending over the entire circumference in the intermediate direction in the width direction, and the annular recess 56 is formed on the inner peripheral wall portion. These are connected to the small-diameter recess 52 by communication grooves 58 formed at appropriate locations. Further, an air passage 60 extending through the partition block 38 in the radial direction is formed in the peripheral wall of the small diameter recess 52. The inner end of the air passage 60 is communicated with the small-diameter recess 52, while the outer end of the air passage 60 is opened to the outside at a port 62 projecting from the outer peripheral surface of the partition block 38. It has been.

  The movable partition member 64 is assembled to the large-diameter concave portion 54, and the lid plate metal fitting 66 is assembled on the upper surface of the partition block 38 from above the movable partition member 64.

  5 and 6, the movable partition member 64 has a circular rubber elastic plate 68 having a substantially thin plate shape, and is circular with respect to the outer peripheral surface of the rubber elastic plate 68. The fittings 70 are vulcanized and bonded. The fitting 70 is press-fitted into the large-diameter recess 54 of the partition block 38, so that the opening of the upper central recess 40 is fluid-tightly covered by the movable partition member 64, and is thus movable. While the pressure receiving chamber 34 is formed above the partition member 64, a sealed working air chamber 72 is formed below the movable partition member 64.

  The rubber elastic plate 68 is integrally formed with a ring-shaped elastic protrusion 74 extending continuously or discontinuously in the circumferential direction at a portion of the partition block 38 positioned on the substantially inner peripheral edge of the step surface 50. Yes. In addition, a substantially plate-shaped contact support portion 76 that protrudes larger on both the upper and lower surfaces is integrally formed at an appropriate number of locations (four locations in the present embodiment) on the circumference of the elastic projection 74. In the present embodiment, the size between the protruding front end surfaces of both the upper and lower elastic protrusions 74, 74 in the rubber elastic plate 68 is set slightly smaller than the axial dimension of the fitting 70, and The dimension between the projecting tip surfaces of both contact support portions 76 and 76 is set to be the same as or slightly larger than the axial dimension of the fitting 70.

  Furthermore, a hard restraint plate 78 made of metal or synthetic resin is fixed to the movable partition member 64 in an embedded state with respect to the central portion of the rubber elastic plate 68. In particular, in the present embodiment, as shown in FIG. 7, the restraint plate 78 has a substantially shallow dish shape with a slightly recessed central portion, so that the deformation rigidity is improved despite being thin. The restraint plate 78 has an outer dimension larger than the inner diameter dimension of the upper central recess 40 of the partition block 38, and the outer peripheral edge of the restraint plate 78 extends to the step surface 50.

  In addition, notches 80 are provided in a plurality of locations corresponding to the upper and lower contact support portions 76 and 76 on the outer peripheral edge portion of the restraint plate 78 so as to escape the formation portions of the contact support portions 76 and 76. The restraint plate 78 is attached to the rubber elastic plate 68. In addition, a circular hole 82 is provided in the center of the restraining plate 78 and filled with a rubber elastic plate 68 so that the fixing strength to the rubber elastic plate 68 is improved.

  Further, the outer peripheral portion of the rubber elastic plate 68 is thin at a portion located between the elastic protrusion 74 and the fitting 70. Thereby, the outer periphery movable rubber film part 84 is formed with an annular plate shape extending in the circumferential direction with a predetermined width. The outer peripheral movable rubber film portion 84 is positioned on the opening of the annular recess 56 formed in the step surface 50 of the partition block 38.

  On the other hand, as shown in FIG. 8, the cover plate metal fitting 66 has a thin and substantially disk shape as a whole, and a slight stepped portion 86 is formed in the radially intermediate portion, and the outer peripheral edge. A central portion protrudes downward from the portion. The lid plate metal 66 is overlapped on the upper surface of the partition block 38, and the stepped portion 86 is fitted into the opening of the upper central recess 40 of the partition block 38 so as to be positioned and assembled in the radial direction. Yes.

  In addition, a circular central through-hole 88 is provided in the center portion of the lid plate metal 66, and a plurality of outer peripheral through-holes 90 extending in the circumferential direction with a predetermined width are provided around the central through-hole 88. It is penetrating. When the cover plate metal fitting 66 is assembled to the partition block 38, the central movable plate portion 92 of the rubber elastic plate 68 reinforced by the restraining plate 78 faces the pressure receiving chamber 34 through the central through hole 88. At the same time, the outer peripheral movable rubber film portion 84 faces the pressure receiving chamber 34 through the outer peripheral through hole 90.

  Furthermore, a notch window 94 is provided at one place on the outer peripheral edge of the cover plate metal fitting 66, and the notch window 94 and the circumferential recess groove 44 provided in the partition block 38 and the axial recess are provided. The groove 46 is aligned with the common upper opening. In addition, in order to align the upper openings of the cutout window 94 and the concave grooves 44 and 46 with each other, a positioning projection 96 is provided on the upper end surface of the partition block 38 at an appropriate position on the circumference, and Positioning holes 98 are formed in corresponding portions of the cover plate metal fitting 66, and the positioning in the circumferential direction is realized by the engaging action of the positioning protrusions 96 and the positioning holes 98.

  Thus, under the assembled state of the rubber elastic plate 68 and the lid plate metal fitting 66 to the partition block 38 as described above, each contact support portion 76 of the rubber elastic plate 68 is as shown in FIG. Each front end surface is in contact with the stepped surface 50 of the partition block 38 or the lower surface of the cover plate metal piece 66 and is appropriately compressed as necessary. Further, as shown in FIG. 10, the elastic protrusion 74 is positioned with a slight gap with respect to the step surface 50 of the partition block 38 or the lower surface of the cover plate metal fitting 66. When the pressure variation of the pressure receiving chamber 34 is exerted on the rubber elastic plate 68, the rubber elasticity is based on the pressure difference between the pressure receiving chamber 34 and the working air chamber 72 exerted on the upper and lower surfaces of the rubber elastic plate 68. The plate 68 is displaced or deformed.

  Here, the deformation of the central movable plate portion 92 of the rubber elastic plate 68 is restricted by the restraining plate 78 that is embedded and fixed, and the displacement that is allowed mainly based on the elastic deformation of the contact support portions 76 and 76. Can be born. On the other hand, the outer peripheral movable rubber film portion 84 is made thin so that elastic deformation is easily allowed, and displacement due to the deformation is generated. The space behind the central movable plate portion 92 and the space behind the outer peripheral movable rubber film portion 84 are stably maintained in a communication state by the communication groove 58, and substantially function as a single air chamber. It is like that.

  The openings of the circumferential groove 44 and the axial groove 46 formed on the outer peripheral surface of the partition block 38 are both fluid-tightly covered with the second mounting bracket 14. By covering the circumferential concave groove 44, the first orifice passage 100 that allows the pressure receiving chamber 34 and the equilibrium chamber 36 to communicate with each other is formed in a state in which the pressure receiving chamber 34 and the equilibrium chamber 36 are always in communication with each other. Further, when the axial groove 46 is covered, it is opened from the communication hole 48 of the partition block 38 to the equilibrium chamber 36 through the lower central recess 42, and the equilibrium chamber 36 is communicated with the pressure receiving chamber 34. Two orifice passages 102 are formed.

  In particular, in the present embodiment, the second orifice passage 102 is formed with substantially the same passage cross-sectional area and a shorter passage length than the first orifice passage 100. As a result, the second orifice passage 102 is tuned to a higher frequency region than the first orifice passage 100. Specifically, it is tuned so as to exhibit high damping characteristics against vibrations in a low frequency region around 10 Hz, such as engine shake, based on the resonance action of the fluid flowing through the first orifice passage 100. At the same time, the low dynamic spring effect is tuned based on the resonance action of the fluid flowing through the second orifice passage 102 with respect to vibration in the middle frequency range of about 20 to 40 Hz such as idling vibration. .

  As described above, the mount configured by assembling the partition member 28 and the rubber diaphragm 30 to the integrally vulcanized molded product of the main rubber elastic body 16 having the first mounting bracket 12 and the second mounting bracket 14. A bracket 18 is further assembled to the main body. The bracket 18 has a substantially bottomed cylindrical shape with a large diameter and a deep bottom as a whole, and is externally fixed to the second mounting bracket 14. A plurality of outwardly extending legs 103 are welded to the outer peripheral surface of the lower portion of the bracket 18, and each of the legs 103 is bolted to the body of the automobile so that the second mounting bracket 14 is secured. However, it can be attached to the body of an automobile via the bracket 18.

  The bracket 18 is sufficiently deep with respect to the second mounting bracket 14, and the bracket 18 has a sufficient size at the bottom of the bracket 18 with the second mounting bracket 14 fitted and fixed. An internal space 104 is formed. The internal space 104 allows the rubber diaphragm 30 to bulge and deform sufficiently sufficiently.

  Further, a pneumatic actuator 106 is provided at the bottom of the bracket 18. The pneumatic actuator 106 uses the bottom portion of the bracket 18 for the base housing 108, and is assembled to the base housing 108 so that the output member 110 serving as valve means is located inside the bracket 18. Yes.

  The output member 110 includes a partition rubber 112 having a generally hat shape as a whole, and a central portion of the partition rubber 112 is an output portion 114 having an inverted cup shape, and an outer peripheral portion thereof is the output portion. A tapered flange-shaped elastic peripheral wall portion 116 that extends obliquely downward from the peripheral edge of the lower end opening 114 is formed. In addition, a hard reinforcing member 118 made of metal or synthetic resin is embedded and fixed to the output portion 114, while an annular press fitting 120 is vulcanized and bonded to the outer peripheral edge portion of the elastic peripheral wall portion 116. ing.

  The press fitting 120 is press-fitted and fixed to the bottom peripheral wall of the bracket 18 so that the outer peripheral edge of the partition rubber 112 is brought into fluid tight contact with the bottom surface of the base housing 108 formed by the bracket 18. Yes. As a result, the pneumatic actuator 106 is configured in which the opening of the output member 110 is covered with the bottom wall portion of the base housing 108 and the regulated air chamber 122 is formed therein.

  In particular, in the present embodiment, the compression coil spring 124 is housed and assembled, so that a biasing force in the separation direction is constantly applied between the output portion 114 and the base housing 124. An air port 126 is provided through the center of the bottom of the base housing 108. The pressure of the regulated air chamber 122 can be controlled from the outside through the air port 126.

  That is, an external pneumatic line 128 is connected to the air port 126 under the mounted state of the anti-vibration mount 10, and the switching valve 130 is connected through the pneumatic line 128. Then, in accordance with the switching operation of the switching valve 130, the atmospheric pressure and the negative pressure source 132 are selectively connected to the regulated air chamber 122.

  In a state where the regulated air chamber 122 is connected to the atmosphere, the elasticity of the elastic peripheral wall portion 116 and the elasticity of the compression coil spring 124 act on the output portion 114, so that the output portion 114 is elastically upward. The rubber diaphragm 30 is urged upward and held against the central lower surface of the partition member 28. Here, since the outer shape of the output portion 114 is larger than the opening diameter of the lower central recess 42 formed in the central lower surface of the partition member 28, the central portion of the rubber diaphragm 30 is the lower central portion. It will press against the opening of the recess 42 and cover it substantially fluid tightly, thereby blocking the second orifice passage 102 that opens into the balancing chamber 36 through the lower central recess 42. ing.

  On the other hand, under the state where the regulated air chamber 122 is connected to the negative pressure source 132, the negative pressure exerted on the working chamber and the external atmospheric pressure are resisted against the elasticity of the elastic peripheral wall 116 and the elasticity of the compression coil spring 124. Based on the pressure difference, the output unit 114 is sucked inward of the pressure-adjusting air chamber 122 and is displaced downward in the axial direction. Therefore, the rubber diaphragm 30 is separated from the opening of the lower central recess 42, and the second orifice passage 102 is opened and communicated.

  Further, by connecting the switching valve 130 constituting such an air pressure control system to the port portion 62 through the air pressure line 128, substantially the same pressure as the pressure exerted on the regulated air chamber 122 is applied to the working air. It is also applied to the chamber 72 at the same time.

  By applying atmospheric pressure to the working air chamber 72, the elastic displacement of the central movable plate portion 92 is easily permitted in the upper central recess 40, and the elastic deformation of the outer peripheral movable rubber film portion 84 is easily permitted. It has become so. On the other hand, when negative pressure is applied to the working air chamber 72, both the central movable plate portion 92 and the outer peripheral movable rubber film portion 84 are sucked into the working air chamber 72 and held in a restrained state by air pressure. It has become

  Here, in the present embodiment, the switching valve 130 is switched by the control device 134 according to the traveling state of the automobile and the stopped state. That is, under the traveling state, the working air chamber 72 and the regulated air chamber 122 are connected to the atmosphere. On the other hand, when the vehicle is stopped, the working air chamber 72 and the regulated air chamber 122 are connected to the negative pressure source 132. The control device 134 is advantageously configured by outputting a drive control signal to an electromagnetic solenoid that constitutes the switching valve 130 by, for example, a speed sensor or the like.

  Therefore, in the engine mount having the above-described structure, the movable partition made up of the central movable plate portion 92 and the outer peripheral movable rubber film portion 84 with respect to the low-frequency large-amplitude vibration that is input when climbing over the level difference during traveling. The fluid pressure absorption due to the displacement or deformation of the member 64 cannot follow, and effective pressure fluctuation can be induced in the pressure receiving chamber 34. Thereby, a relative pressure variation is effectively generated between the pressure receiving chamber 34 and the equilibrium chamber 36. Therefore, if the second orifice passage 102 is maintained in the shut-off state by the valve means, the amount of fluid flow through the first orifice passage 100 can be advantageously ensured, and the first orifice passage 100 can be caused to flow. A high damping effect based on the resonance action of the fluid is exhibited, and excellent vibration isolation performance can be realized.

  Further, for the low frequency small amplitude vibration input in the normal running state, the second orifice passage 102 is maintained in the shut-off state by the valve means as in the case of the above-described low frequency large amplitude vibration. The amount of fluid flow through the first orifice passage 100 can be advantageously ensured, and a high damping effect based on the resonance action of the fluid flowing through the first orifice passage 100 is exerted, resulting in excellent vibration isolation performance. Can be realized. Although there is a concern about the pressure absorption of the pressure receiving chamber 34 by the movable partition member 64, the fluid tightness on the outer peripheral side of the central movable plate portion 92 is ensured by the peripheral movable rubber film portion 84, and the central movable plate portion. Since 92 is hard and the deformation amount of the movable partition member 64 is suppressed, a sufficiently effective pressure fluctuation is still induced in the pressure receiving chamber 34.

  Further, since the pressure fluctuation in the pressure receiving chamber 34 is very small with respect to the high frequency fine amplitude vibration input during traveling, the pressure fluctuation in the pressure receiving chamber 34 is effectively absorbed or displaced by the displacement or deformation of the movable partition member 64. Can be reduced. In particular, the central movable plate portion 92 of the movable partition member 64 is formed in the central portion and can advantageously ensure an effective area, and the outer peripheral movable rubber film portion 84 that supports the outer peripheral edge thereof in a fluid-tight manner is deformed. Therefore, it is possible to advantageously follow and displace the pressure fluctuation in the high frequency region in the pressure receiving chamber 34, and the pressure fluctuation in the pressure receiving chamber 34 can be suppressed. Therefore, at the time of vibration input in the high frequency range, significant pressure fluctuations in the pressure receiving chamber 34 can be avoided by the movable partition member 64 even in a state where the first and second orifice passages 102 are substantially closed. Thus, an excellent vibration isolating performance can be exhibited by an effective vibration insulating action based on the low dynamic spring characteristics.

  Furthermore, with respect to medium-frequency medium-amplitude vibration corresponding to idling vibration or the like generated in a stopped state, negative pressure is applied to the working air chamber 72 through the pneumatic pipe 128, so that the second orifice passage 102 is communicated. At the same time, the movable partition member 64 is restrained by suction to suppress displacement or deformation. As a result, the pressure absorption by the movable partition member 64 is prevented, and the pressure fluctuation in the pressure receiving chamber 34 is effectively induced, and the amount of fluid flowing through the second orifice passage 102 can be advantageously ensured. Therefore, the vibration isolation effect based on the resonance action of the fluid is effectively exhibited. Although the first orifice passage 100 is also in communication, the input vibration having a frequency exceeding the tuning frequency is substantially closed due to the anti-resonant action of the flowing fluid.

  Further, in the present embodiment, the amount of displacement of the movable partition member 64 is limited by forming the elastic projection 74 and the contact support portion 76 as elastic contact projections on the movable partition member 64, thereby reducing the low frequency. Pressure absorption by the movable partition member 64 at the time of input of small amplitude vibration can be suppressed more effectively.

  Further, in the vibration proof mount of the present embodiment, the working air chamber 72 is urged by urging the output member 110 upward in the axial direction toward the opening of the lower central recess 42 connected to the second orifice passage 102. Since the output member 110 of the pneumatic actuator 106 holds the lower central recess 42 in the cut-off state via the rubber diaphragm 30 in a state where the pressure is substantially atmospheric pressure, the pneumatic actuator 106 is operated. The negative pressure that can be easily obtained in an automobile can be skillfully used.

  Further, in the vibration isolating mount of the present embodiment, the working air chamber 72 and the pneumatic actuator 106 are subjected to a negative pressure when the automobile is stopped, and a substantially atmospheric pressure is applied to the working air chamber 72 when the automobile is running. And a pneumatic control device for continuously controlling the air pressure exerted on the pneumatic actuator 106. This makes it possible to easily supply and discharge air pressure to / from the working air chamber 72 and the pneumatic actuator 106 with a simple control mode.

  Further, in the vibration isolating mount of the present embodiment, the restraint plate 78 is fixedly embedded in the central movable plate portion 92 of the movable partition member 64, so that it is caused by unnecessary deformation in the central movable plate portion 92. Absorption of pressure fluctuations in the pressure receiving chamber 34 at the time of vibration input in the low to medium frequency range can be suppressed more reliably, and the vibration isolation effect due to fluid flow in the first orifice passage 100 and the second orifice passage 102 is effective. Is demonstrated.

  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.

  Specifically, for example, in the present embodiment, the central movable plate portion 92 is reinforced by embedding a hard restraint plate 78, but the restraint plate 78 may be omitted. That is, by making the rubber elastic plate 68 thick, for example, if necessary, it can be made sufficiently hard so that the function as the central movable plate portion 92 is exhibited without being reinforced by the restraint plate 78 or the like. Is possible.

  In the above embodiment, the compression coil spring 124 is used as a biasing means for pressing the pneumatic actuator 106 against the opening of the lower central recess 42 when the working air chamber 72 is at substantially atmospheric pressure. Although used, the urging means is not limited to that of the above embodiment. Specifically, for example, it is possible to hold only the elasticity of the partition rubber elastic body 54 so as to hold it in contact, or it is possible to use a leaf spring or the like instead of the compression coil spring 124. is there.

  In addition, in the said embodiment, although the specific example of what applied this invention to the engine mount for motor vehicles was shown, other than this, this invention can be applied advantageously also to engine mount apparatuses other than a motor vehicle. Of course.

It is a longitudinal cross-sectional view which shows the vibration proof mount as one Embodiment of this invention, Comprising: It is a figure corresponded in the II cross section in FIG. It is a top view which shows the partition block which comprises the vibration proof mount shown by FIG. FIG. 3 is a bottom view of the partition block shown in FIG. 2. It is a perspective view which shows the partition block shown by FIG. It is a top view which shows the movable partition member which comprises the vibration proof mount shown by FIG. FIG. 6 is a bottom view of the movable partition member shown in FIG. 5. It is a top view which shows the restraint plate which comprises the vibration proof mount shown by FIG. It is a top view which shows the cover plate metal fitting which comprises the vibration proof mount shown by FIG. It is a longitudinal cross-sectional view which expands and shows the contact | abutting support part in the vibration proof mount shown by FIG. It is a longitudinal cross-sectional view which expands and shows the elastic protrusion in the vibration isolating mount shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Anti-vibration mount 12 1st mounting bracket 14 2nd mounting bracket 16 Main body rubber elastic body 30 Rubber diaphragm 34 Pressure receiving chamber 36 Equilibrium chamber 64 Movable partition member 72 Working air chamber 84 Outer peripheral movable rubber film part 92 Central movable plate part 100 First orifice passage 102 Second orifice passage 106 Pneumatic actuator 114 Output section

Claims (6)

A first attachment member attached to one of the power unit side member and the vehicle body side member;
A second attachment member attached to the other of the power unit side member and the vehicle body side member;
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 is constituted by the main rubber elastic body and in which an incompressible fluid is enclosed;
An equilibrium chamber in which a part of the wall is made of a flexible membrane and volume change is allowed;
A first orifice passage tuned to a low frequency region substantially corresponding to an engine shake, which allows the pressure receiving chamber and the equilibrium chamber to communicate with each other;
A second orifice passage tuned to an intermediate frequency range substantially corresponding to idling vibration, which allows the pressure receiving chamber and the equilibrium chamber to communicate with each other;
Valve means for communicating / blocking the second orifice passage;
A pneumatic actuator that is actuated by air pressure exerted from outside to drive the valve means;
The central part is a hard central movable plate part, and the outer peripheral part is an easily movable outer peripheral movable rubber film part, and displacement or deformation in the central movable plate part and the outer peripheral movable rubber film part is allowed. A movable partition member that is arranged to constitute another part of the wall portion of the pressure receiving chamber;
An air pressure switching type fluid-filled engine mount, comprising: a working air chamber formed on the opposite side of the pressure receiving chamber with the movable partition member interposed therebetween and capable of adjusting air pressure from the outside.   An elastic contact protrusion is formed to protrude from the outer peripheral edge portion of the central movable plate portion of the movable partition member, and is elastic with respect to the displacement regulating member supported by the second attachment member or the second attachment member. 2. The air pressure switching type fluid-filled engine mount according to claim 1, further comprising a displacement amount limiting means for bufferingly limiting a displacement amount of the central movable plate portion by contacting the contact protrusion.   In the pneumatic actuator, the valve means is driven so that the second orifice passage is shut off when a substantially atmospheric pressure is applied from the outside, while the negative pressure is applied from the outside. 3. The air pressure switching type fluid-filled engine mount according to claim 1 or 2, wherein the valve means is driven so that the orifice passage is in a communicating state.   While the negative pressure is exerted on the working air chamber and the pneumatic actuator when the automobile is stopped, the air pressure exerted on the working air chamber and the pneumatic actuator is exerted by applying a substantially atmospheric pressure when the automobile is running. The air pressure switching type fluid-filled engine mount according to any one of claims 1 to 3, further comprising air pressure control means for controlling the air pressure in conjunction with each other.   5. A hard restraint plate is disposed on the central movable plate portion of the movable partition member, and the outer peripheral movable rubber film portion is bonded to an outer peripheral edge portion of the restraint plate. Air pressure switching type fluid-filled engine mount. When the input vibration exerted between the first mounting member and the second mounting member is a minute amplitude vibration of ± 0.05 mm or less, pressure fluctuations induced in the pressure receiving chamber can be substantially absorbed. However, if the input vibration exerted between the first mounting member and the second mounting member is a small amplitude vibration of around ± 0.1 mm or a large amplitude vibration of ± 1.0 mm or more, the pressure receiving chamber 6. The air pressure switching type fluid-filled type according to claim 1, wherein a displacement or deformation characteristic of the movable partition member is set so as not to substantially absorb an induced pressure fluctuation. Engine mount.

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