JP6240482B2 - Fluid filled vibration isolator - Google Patents

Description

  The present invention relates to a fluid-filled vibration isolator used for an engine mount for automobiles.

  Conventionally, an anti-vibration device is known as a type of anti-vibration support body or anti-vibration coupling body that is interposed between members constituting a vibration transmission system and that anti-vibrates and connects these members. Further, as disclosed in Japanese Patent Application Laid-Open No. 2012-241842 (Patent Document 1) and the like, there is also a fluid-filled vibration damping device in which an incompressible fluid is sealed for the main purpose of improving vibration damping performance. It has been proposed and applied to automobile engine mounts. In this fluid-filled vibration isolator, the first mounting member and the second mounting member are elastically connected by the main rubber elastic body, and on both sides of the partition member supported by the second mounting member In addition, a pressure receiving chamber and an equilibrium chamber in which an incompressible fluid is sealed are formed, and the pressure receiving chamber and the equilibrium chamber are connected to each other by an orifice passage.

  By the way, in the fluid-filled vibration isolator, an excellent vibration isolating effect is exerted against the input vibration of the resonance frequency (tuning frequency) of the fluid flowing through the orifice passage, while the input vibration having a frequency outside the tuning frequency is exhibited. In contrast, it is difficult to obtain an effective anti-vibration effect. Therefore, in Patent Document 1, a first orifice passage and a second orifice passage tuned to a higher frequency than that are provided, and a switching valve disposed in the passage of the second orifice passage is used. The communication and blocking of the second orifice passage can be switched according to the amplitude of the input vibration. As a result, when a low-frequency large-amplitude vibration corresponding to an engine shake or the like is input, the second orifice passage is blocked, and the vibration isolation effect by the first orifice passage is exhibited and a high-frequency equivalent to idling vibration or the like. When small amplitude vibration is input, the second orifice passage is held in communication and the vibration prevention effect of the second orifice passage is exhibited. Can be obtained.

  However, when an amplitude-dependent switching type switching valve is arranged in the passage of the second orifice passage as in Patent Document 1, for example, the degree of freedom of tuning of the second orifice passage is limited, and the switching valve The deformation may cause problems such as changes in the cross-sectional area of the second orifice passage, resulting in unstable characteristics, and difficulty in securing a space for arranging the switching valve in the second orifice passage. there were. Therefore, depending on the required characteristics, there may be a case where a vibration isolation effect based on the fluid flow action cannot be sufficiently obtained.

JP 2012-241842 A

  The present invention has been made in the background of the above-described circumstances, and the problem to be solved is to selectively reduce the vibration isolation effect of the first orifice passage and the second orifice passage according to the amplitude of the input vibration. An object of the present invention is to provide a fluid-filled vibration isolator having a novel structure that can be obtained efficiently.

  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.

That is, according to the first aspect of the present invention, the first mounting member and the second mounting member are elastically connected by the main rubber elastic body, and on both sides of the partition member supported by the second mounting member. Each of the pressure receiving chambers, in which a part of the wall portion is configured by the main rubber elastic body, and an equilibrium chamber in which a part of the wall portion is configured by a flexible film is formed, An incompressible fluid is sealed in the equilibrium chamber, and a first orifice passage and a second orifice passage are formed to communicate the pressure receiving chamber and the equilibrium chamber with each other, and a tuning frequency of the second orifice passage is formed. In the fluid-filled vibration isolator set at a frequency higher than the tuning frequency of the first orifice passage, a switching passage connected in series with the second orifice passage is formed, and the switching passage The switching valve is The switching passage is arranged in a communication state, and the switching passage is switched between communication and blocking according to the amplitude of the input vibration, and the switching valve is provided. The resonance frequency of the switching passage is set to be higher than the tuning frequency of the second orifice passage, while the switching valve is supported by the partition member and the valve disposed in the switching passage The fluid flow in the switching passage is blocked in both directions by the valve portion that is elastically deformed when large amplitude vibration is input .

  According to the fluid-filled vibration isolator having the structure according to the first aspect as described above, the switching valve is switched between communicating and blocking according to the amplitude of the input vibration, so that a large valve like an engine shake can be obtained. When the amplitude vibration is input, the switching passage is blocked by the switching valve, and when the small amplitude vibration such as idling vibration is input, the switching passage is maintained in a communication state. As a result, communication and blocking of the second orifice passage connected in series with the switching passage are switched by the switching valve, and the vibration isolation effect by the first orifice passage and the vibration isolation effect by the second orifice passage are It is exhibited selectively according to the amplitude of the input vibration.

  In addition, since the switching valve is disposed outside the second orifice passage and disposed in the switching passage, the passage of the switching passage provided with the switching valve is not interrupted without adversely affecting the vibration isolation performance of the second orifice passage. The area and the like can be set as appropriate, and for example, improvement in vibration isolation performance can be achieved by promptly switching between communication and blocking of the switching passage.

  Further, the switching valve is disposed in the switching passage out of the second orifice passage so that the second orifice passage is not constricted by the switching valve. Therefore, a large degree of freedom in setting the cross-sectional area of the second orifice passage is secured, and the passage length of the second orifice passage can be set large while maintaining tuning of the second orifice passage to a specific frequency. . As a result, a large equivalent mass of liquid column resonance in the second orifice passage is ensured, and a vibration isolation effect based on the fluid action of the fluid flowing through the second orifice passage is advantageously exhibited.

  Further, the resonance frequency of the fluid flowing through the switching passage provided with the switching valve is set to be higher than the tuning frequency of the second orifice passage. Therefore, at the time of vibration input at a frequency corresponding to the tuning frequency of the second orifice passage, the switching passage is held in communication, and fluid flow through the second orifice passage is effectively generated. In addition, since the resonance frequency of the switching passage is higher than the tuning frequency of the second orifice passage, even if the resonance frequency of the switching passage changes due to deformation of the switching valve, the tuning frequency of the second orifice passage In this case, the switching passage is hardly blocked due to anti-resonance, and the intended vibration isolation effect can be obtained effectively.

In addition, the switching valve has a structure that keeps the switching passage in communication at all times except when large-amplitude vibration is input. Etc. are avoided.
Furthermore, according to this aspect, since the switching valve is supported by the partition member in the support portion, the switching passage is stably maintained in a continuous communication state when the switching valve is opened. Moreover, since the valve portion for switching between communication and blocking of the switching passage is formed integrally with the support portion, the number of parts of the switching valve can be reduced. In addition, when the large amplitude vibration is input, the valve portion of the switching valve blocks the fluid flow to both sides of the switching passage in the length direction of the passage, so that the vibration isolation effect by the first orifice passage is more efficient. Demonstrated.

  According to a second aspect of the present invention, in the fluid-filled vibration isolator described in the first aspect, the switching passage is formed on the pressure receiving chamber side of the second orifice passage.

  According to the second aspect, the flexible membrane that can be easily deformed blocks the opening of the switching passage or interferes with the switching valve to hinder the opening and closing operation. The vibration-proof performance can be obtained stably.

  According to a third aspect of the present invention, in the fluid-filled vibration isolator described in the first or second aspect, a cross-sectional area of the switching passage in which the switching valve is disposed is the second orifice passage. It is made larger than the passage cross-sectional area.

  According to the third aspect, the fluid flow through the second orifice passage is efficiently generated, and the vibration isolation effect based on the fluid flow action is advantageously exhibited.

  According to a fourth aspect of the present invention, in the fluid-filled vibration isolator described in any one of the first to third aspects, the switching passage in which the switching valve is disposed passes the partition member in the circumferential direction. Is formed in an annular shape.

  According to the fourth aspect, it is possible to reduce the operation stroke of the switching valve by narrowing the switching passage in the switching valve installation region while securing the passage sectional area by making the switching passage annular. As a result, the communication between the switching passage and the switching between the passages can be realized promptly and with high reliability.

  According to a fifth aspect of the present invention, in the fluid-filled vibration isolator described in any one of the first to fourth aspects, the first orifice passage extends in an outer circumferential portion of the partition member in the circumferential direction. And the switching passage is communicated with an intermediate portion of the first orifice passage, and the second orifice passage is formed by partially using the first orifice passage. .

  According to the fifth aspect, a large passage length of the first orifice passage can be ensured, and the vibration isolation effect by the first orifice passage is advantageously exhibited. Further, since the second orifice passage is formed by partially using the first orifice passage, the structure can be simplified and the length of the second orifice passage can be sufficiently secured. The vibration-proofing effect by the second orifice passage is also advantageously exhibited.

  According to the present invention, the switching passage in which the switching valve is disposed is connected in series with the second orifice passage, and the resonance frequency of the switching passage is set higher than the tuning frequency of the second orifice passage. Has been. Therefore, both the vibration isolation effect by the first orifice passage and the vibration isolation effect by the second orifice passage are effectively exhibited. In particular, since the switching valve is arranged at a position off the second orifice passage, the passage sectional area of the second orifice passage can be set large while effectively opening and closing the switching passage by the switching valve. As a result, it is possible to advantageously obtain an anti-vibration effect by the second orifice passage.

It is a longitudinal cross-sectional view of the engine mount as 1st embodiment of this invention, Comprising: II sectional drawing of FIG. II-II sectional drawing of FIG. The perspective view of the partition member which comprises the engine mount of FIG. The graph which shows the damping characteristic at the time of the large amplitude vibration input in the engine mount of FIG. The graph which shows the spring characteristic at the time of the small amplitude vibration input in the engine mount of FIG. It is a longitudinal cross-sectional view of the engine mount as 2nd embodiment of this invention, Comprising: VI-VI sectional drawing of FIG. VII-VII sectional drawing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show an engine mount 10 for an automobile as a first embodiment of a fluid filled type vibration damping device having a structure according to the present invention. The engine mount 10 has a structure in which a first mounting member 12 and a second mounting member 14 are elastically connected by a main rubber elastic body 16. In the following description, the vertical direction means, in principle, the vertical direction in FIG. 1, which is the mount central axis direction.

  More specifically, the first mounting member 12 is a high-rigidity member formed of iron, aluminum alloy, or the like, and has a small-diameter, generally cylindrical shape, and a flange portion 18 that protrudes from the upper end to the outer peripheral side. Is integrated. Further, the first mounting member 12 is formed with a screw hole 20 extending vertically on the central axis and opening on the upper surface, and a thread is formed on the inner peripheral surface.

  The second mounting member 14 is a highly rigid member similar to the first mounting member 12 and has a thin cylindrical shape with a large diameter. In the present embodiment, the upper part has a stepped cylindrical shape with a larger diameter than the lower part.

  The first mounting member 12 is arranged above the second mounting member 14 on the same central axis, and the first mounting member 12 and the second mounting member 14 are elasticized by the main rubber elastic body 16. It is connected. The main rubber elastic body 16 has a thick, large-diameter, generally frustoconical shape. The first attachment member 12 is vulcanized and bonded to the small-diameter end, and the outer periphery of the large-diameter end. A second mounting member 14 is vulcanized and bonded to the surface. In the present embodiment, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting member 12 and the second mounting member 14.

  Furthermore, a large-diameter recess 22 is formed in the main rubber elastic body 16. The large-diameter recess 22 is a recess that opens to the large-diameter side end face of the main rubber elastic body 16 and has a reverse mortar-shaped tapered shape in which the upper bottom wall portion gradually decreases in diameter upward. Yes.

  Furthermore, a seal rubber layer 24 extends downward from the outer peripheral end of the main rubber elastic body 16. The seal rubber layer 24 is a rubber elastic body having a thin-walled and large-diameter substantially cylindrical shape integrally formed with the main rubber elastic body 16, and covers the entire inner peripheral surface of the lower portion of the second mounting member 14. Thus, the second mounting member 14 is vulcanized and bonded.

  A flexible film 26 is attached to the lower end portion of the second attachment member 14. The flexible film 26 has a thin and substantially disk shape and is loosened up and down so that it can be easily deformed. Further, an annular fixing member 28 is fixed to the outer peripheral surface of the flexible film 26, and the second mounting member 14 having the fixing member 28 inserted into the lower end thereof is subjected to diameter reduction processing such as an eight-way drawing. As a result, the flexible film 26 is attached to the second attachment member 14.

  With the attachment of the flexible membrane 26, a fluid chamber 30 is formed between the main rubber elastic body 16 and the flexible membrane 26 in a fluid-tight manner from the external space, and is not compressed inside. Sex fluid is enclosed. The incompressible fluid sealed in the fluid chamber 30 is not particularly limited. For example, water, ethylene glycol, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof is preferably used. Used. Furthermore, a low-viscosity fluid having a viscosity of 0.1 Pa · s or less is desirable in order to advantageously obtain a vibration isolation effect based on the fluid flow action described later.

  The fluid chamber 30 is provided with a partition member 32 shown in FIG. As shown in FIGS. 1 to 3, the partition member 32 has a thick and large-diameter substantially disk shape, and a switching valve 76 described later between the upper partition member 34 and the lower partition member 36 that are stacked one above the other. It is set as the structure which arranged.

  The upper partition member 34 is a hard member made of metal or synthetic resin, and has a substantially bottomed cylindrical shape in the reverse direction. Further, a circumferential groove 40 is formed at the outer peripheral end portion of the upper partition member 34 and extends in a predetermined length that is less than two in the circumferential direction while opening in the outer peripheral surface. The circumferential groove 40 of the present embodiment has a structure in which an upper stage 42 and a lower stage 44 are communicated with each other, and extends in two upper and lower stages.

  Further, three short-circuit holes 46, 46, 46 penetrating vertically are formed in the inner peripheral portion of the upper bottom wall portion of the upper partition member 34. The three short-circuit holes 46, 46, 46 each extend with a predetermined length in the circumferential direction, and are arranged on the same circumference. In addition, between the circumferential directions of the three short-circuit holes 46, 46, 46 in the upper bottom wall portion of the upper partition member 34, an inner circumferential groove 48 that opens to the lower surface is formed. A substantially cylindrical abutting protrusion 50 protruding downward is formed on the inner peripheral side of the groove 48.

  Furthermore, three communication holes 52, 52, 52 penetrating vertically are formed at the outer peripheral end of the upper bottom wall portion of the upper partition member 34. The three communication holes 52, 52, 52 each extend with a predetermined length in the circumferential direction, and are arranged on the same circumference between the radial direction of the circumferential groove 40 and the short-circuit hole 46. An outer circumferential groove 54 opened on the lower surface is formed between the three communication holes 52, 52, 52 in the upper bottom wall portion of the upper partition member 34 in the circumferential direction, and the short-circuit hole 46 and the inner circumferential groove An annular upper clamping protrusion 56 that protrudes downward is formed between 48, the communication hole 52, and the outer circumferential groove 54.

  The lower partition member 36 has a thin-walled, large-diameter, generally annular plate shape, and a substantially cylindrical lower clamping protrusion 58 that protrudes upward at the inner peripheral end portion. Note that the outer diameter dimension of the lower clamping projection 58 is smaller than the inner dimension of the upper partition member 34.

  Then, the upper partition member 34 and the lower partition member 36 are vertically overlapped on the same center axis, and the lower surface of the outer peripheral portion of the upper partition member 34 having a substantially cylindrical shape is formed into a substantially annular plate shape. It is brought into contact with the upper surface of the member 36.

  The partition member 32 having such a structure is disposed in the fluid chamber 30 so as to spread in the direction perpendicular to the axis, and the outer peripheral surface is pressed against the inner peripheral surface of the second mounting member 14 via the seal rubber layer 24. In addition, the outer peripheral end portion is sandwiched between the axial direction of the large-diameter side end surface of the main rubber elastic body 16 and the fixing member 28. As a result, the fluid chamber 30 is divided into two parts up and down across the partition member 32, and a part of the wall portion is formed of the main rubber elastic body 16 above the partition member 32, and internal pressure fluctuations are generated when vibration is input. A pressure receiving chamber 60 is formed, and below the partition member 32, a part of the wall portion is formed of the flexible film 26, and an equilibrium chamber 62 in which volume change is easily allowed is formed. Has been. The pressure receiving chamber 60 and the equilibrium chamber 62 are filled with the incompressible fluid of the fluid chamber 30.

Further, the outer peripheral surface of the partition member 32 is fluid-tightly covered by the second mounting member 14, so that the opening on the outer peripheral side of the circumferential groove 40 is fluid-tightly closed and extends in the circumferential direction. Is formed, one end of the tunnel-shaped flow path is communicated with the pressure receiving chamber 60, and the other end is communicated with the equilibrium chamber 62. Thus, a first orifice passage 64 that connects the pressure receiving chamber 60 and the equilibrium chamber 62 to each other is formed using the circumferential groove 40. The first orifice passage 64 of the present embodiment is tuned to adjust the ratio (A ₁ / L ₁ ) between the passage cross-sectional area (A ₁ ) and the passage length (L ₁ ), which is the resonance frequency of the flowing fluid. The frequency (f ₁ ) is set to a low frequency of about 10 Hz corresponding to engine shake.

  Further, the short-circuit hole 46 has a lower opening located on the inner peripheral side of the lower partition member 36, and both openings communicate with one of the pressure receiving chamber 60 and the equilibrium chamber 62. Thus, a short-circuit passage 66 that connects the pressure-receiving chamber 60 and the equilibrium chamber 62 to each other is formed using the short-circuit hole 46. In the short-circuit passage 66, the ratio of the passage cross-sectional area to the passage length is set to be larger than that of the switching passage 72 described later, and the fluid can flow efficiently with a small flow resistance.

The communication hole 52 has an upper end communicating with the pressure receiving chamber 60 and a lower end communicating with a radial gap 68 between the outer peripheral portion of the upper partition member 34 and the lower clamping protrusion 58 of the lower partition member 36. ing. Further, the lower stage 44 of the circumferential groove 40 communicates with the gap 68 by a connection hole 70 that penetrates the inner peripheral wall portion of the lower stage 44 of the circumferential groove 40. As a result, the switching passage 72 formed by the communication hole 52, the outer circumferential concave groove 54, and the gap 68 is communicated with an intermediate portion of the first orifice passage 64, and constitutes a part of the first orifice passage 64. A second orifice passage 74 is formed by the lower stage 44 of the circumferential groove 40 and the connection hole 70.

  Further, in the present embodiment, the switching passage 72 is formed in series on the pressure receiving chamber 60 side of the second orifice passage 74, and the switching passage 72 communicating with the pressure receiving chamber 60 and the second communicating with the equilibrium chamber 62. Are connected to each other. Accordingly, the pressure receiving chamber 60 and the equilibrium chamber 62 are communicated with each other through the second orifice passage 74 and the switching passage 72. The second orifice passage 74 is formed by using a part of the first orifice passage 64 formed by the lower stage 44 of the circumferential groove 40.

The tuning frequency (f ₂ ) of the second orifice passage 74 is adjusted by adjusting the ratio (A ₂ / L ₂ ) between the passage cross-sectional area (A ₂ ) and the passage length (L ₂ ). Higher than 64 (f ₁ <f ₂ ). In the present embodiment, the tuning frequency of the second orifice passage 74 is set to a medium frequency of about 20 to 40 Hz corresponding to idling vibration.

  A switching valve 76 is disposed between the upper clamping protrusion 56 of the upper partition member 34 and the lower clamping protrusion 58 of the lower partition member 36. The switching valve 76 is formed of a rubber elastic body, and includes an annular support portion 78 sandwiched between the upper and lower partition members 34, 36, a valve portion 80 provided on the outer peripheral side of the support portion 78, and the support portion 78. A relief portion 82 provided on the inner peripheral side is integrally provided.

  The valve portion 80 has an annular shape that extends continuously over the entire circumference, and gradually protrudes to both sides in the axial direction gradually toward the outer circumference side. Further, the inner peripheral end portion of the valve portion 80 and the outer peripheral end portion of the support portion 78 are connected to each other by a thin deformation allowing portion 84 formed integrally. The valve portion 80 can be displaced up and down with respect to the support portion 78 by elastic deformation of the deformation allowing portion 84.

  The relief part 82 protrudes from the support part 78 to the inner peripheral side, and becomes thin while gradually tilting upward as it goes to the inner peripheral side. The relief portion 82 is gradually inclined upward as the entire upper surface goes to the inner peripheral side, while the lower end is gradually inclined upward toward the inner peripheral side, and the base end portion of the lower surface Is a plane extending in a direction substantially perpendicular to the axis.

  The switching valve 76 having such a structure is disposed between the upper partition member 34 and the lower partition member 36. Specifically, the support portion 78 constituting the radial intermediate portion of the switching valve 76 is sandwiched between the upper sandwiching projection 56 of the upper partition member 34 and the lower sandwiching projection 58 of the lower partition member 36. .

  Further, the relief portion 82 of the switching valve 76 is inserted into the short-circuit hole 46 and the inner circumferential concave groove 48, and the projecting tip portion of the relief portion 82 is pressed against the outer circumferential surface of the contact projection 50 of the upper partition member 34. Yes. The pressure of the pressure receiving chamber 60 is exerted on the upper surface of the relief portion 82 through the short-circuit hole 46, and the fluid pressure of the equilibrium chamber 62 is exerted on the lower surface. In the present embodiment, the contact protrusion 50 is gradually reduced in diameter toward the lower side, so that the hydraulic pressure in the equilibrium chamber 62 is exerted on a wider range of the lower surface of the relief portion 82.

  Furthermore, the valve portion 80 of the switching valve 76 is inserted into the communication hole 52 and the outer circumferential groove 54 and disposed in the switching passage 72, and the liquid in the pressure receiving chamber 60 is formed on the upper surface of the valve portion 80 through the communication hole 52. A pressure is exerted, and a fluid pressure in the equilibrium chamber 62 is exerted on the lower surface through the second orifice passage 74 and the gap 68. Further, the outer peripheral surface of the valve portion 80 is disposed opposite to the inner peripheral surface of the upper partition member 34 at a predetermined distance, and the switching passage 72 is kept in a communicating state in a stationary state where no vibration load is input. Has been. In the switching passage 72 of the present embodiment, the communication hole 52 that is an opening on the pressure receiving chamber 60 side extends in a circumferential direction with a predetermined length, and the outer circumferential groove 54 that constitutes the intermediate portion extends over the entire circumference. Extend continuously. As a result, the valve portion 80 of the switching valve 76 is disposed in the switching passage 72 over the entire circumference, and the switching passage 72 narrowed by the arrangement of the valve portion 80 extends the partition member 32 in the circumferential direction. It is formed in an annular shape.

Here, in the switching passage 72 provided with the switching valve 76, the resonance frequency (f ₃ ) of the flowing fluid has a ratio (A ₃ / L ₃ ) between the passage sectional area (A ₃ ) and the passage length (L ₃ ). ) Is set to a higher frequency (f ₂ <f ₃ ) than the second orifice passage 74. Further, the passage sectional area of the switching passage 72 provided with the switching valve 76 is larger than the passage sectional area of the second orifice passage 74 (A ₃ > A ₂ ). The switching passage 72 is partially narrowed in the region where the switching valve 76 (valve portion 80) is disposed, and the passage cross-sectional area in the region where the switching valve 76 is disposed is substantially equal to the switching passage 72. It is a passage cross-sectional area.

  The engine mount 10 having the structure according to the present embodiment is configured such that the first mounting member 12 is mounted on a power unit (not shown) and the second mounting member 14 is also mounted on a vehicle body (not shown). It is attached to.

  In such a vehicle mounting state, when a low-frequency large-amplitude vibration corresponding to an engine shake is input between the first mounting member 12 and the second mounting member 14, the first mounting is performed between the pressure receiving chamber 60 and the equilibrium chamber 62. The fluid flow is generated through the orifice passage 64, and the vibration isolation effect (high damping effect) based on the fluid flow action is exhibited.

  In addition, when a large amplitude vibration is input, the deformation permitting portion 84 is deformed by the relative pressure fluctuation between the pressure receiving chamber 60 and the equilibrium chamber 62, and the valve portion 80 of the switching valve 76 is swung in a swinging manner. The upper and lower end portions of the outer peripheral surface of the valve portion 80 are pressed against the outer peripheral wall surface of the switching passage 72. Accordingly, the switching passage 72 is blocked by the valve portion 80 of the switching valve 76, and the second orifice passage 74 communicated in series with the switching passage 72 is substantially blocked. Therefore, the amount of fluid flowing through the first orifice passage 64 is efficiently ensured, and the vibration isolation effect by the first orifice passage 64 is advantageously exhibited.

  In particular, in this embodiment, regardless of whether positive pressure or negative pressure is applied to the pressure receiving chamber 60, the switching passage 72 is blocked by the valve portion 80 of the switching valve 76, and the fluid flow in the switching passage 72 is made more efficient. By being limited, the vibration isolation effect by the first orifice passage 64 is advantageously exhibited. In addition, the valve portion 80 of the present embodiment has upper and lower end portions that come into contact with the wall surface on the outer peripheral side of the switching passage 72 gradually becoming thinner toward the upper and lower outer sides, and there is a shear spring that affects the elasticity at the time of contact. Since it is made small as it goes to the upper and lower outer sides, the contact sound is reduced.

  In addition, since the valve portion 80 of the switching valve 76 is disposed not in the second orifice passage 74 but in the switching passage 72, the outer peripheral surface of the valve portion 80 and the inner wall surface on the outer peripheral side of the switching passage 72 Even if the distance is set to be small, the influence on the vibration isolation characteristics by the second orifice passage 74 is reduced or avoided. As a result, the communication and blocking of the switching passage 72 can be switched more accurately and promptly by the valve portion 80, and as shown in FIG. 4 as an embodiment, compared to an engine mount having a conventional structure (comparative example). Thus, the vibration isolation effect by the first orifice passage 64 can be advantageously obtained.

  In particular, in this embodiment, the constriction portion by the valve portion 80 in the switching passage 72 is provided in an annular shape continuously in the circumferential direction, and while securing the passage cross-sectional area of the switching passage 72, The distance between the opposed surfaces of the switching passage 72 and the inner surface of the outer peripheral wall can be set small, and the switching operation of the switching passage 72 by the valve portion 80 is realized quickly and with high reliability. The passage cross-sectional area of the switching passage 72 is partially reduced in the region where the valve portion 80 of the switching valve 76 is disposed, so that the gap between the outer peripheral surface of the valve portion 80 and the outer peripheral wall inner surface of the switching passage 72 is reduced. The flow velocity of the fluid flowing through the flow path is faster than other areas in the switching passage 72.

  On the other hand, when medium-frequency small-amplitude vibration corresponding to idling vibration or the like is input between the first mounting member 12 and the second mounting member 14, the displacement amount of the valve portion 80 is small and the switching passage 72 is in a communication state. As a result, the fluid flow is generated between the pressure receiving chamber 60 and the equilibrium chamber 62 through the second orifice passage 74. Thereby, the anti-vibration effect (low dynamic spring effect) based on the fluid flow action is exhibited. Since the first orifice passage 64 tuned to a low frequency is substantially cut off by anti-resonance when the medium frequency vibration is input, a large amount of fluid flowing through the second orifice passage 74 is ensured. .

  Here, in the engine mount 10, the valve portion 80 of the switching valve 76 is disposed in the switching passage 72 and is disposed at a position away from the second orifice passage 74. A large passage cross-sectional area is secured without being constricted by the valve portion 80. Therefore, a large equivalent mass is ensured in the liquid column resonance of the second orifice passage 74, and as shown in the embodiment in FIG. It is possible to obtain more advantageous than the example).

Furthermore, since the resonance frequency (f ₃ ) of the switching passage 72 in which the valve portion 80 is disposed is set higher than the tuning frequency (f ₂ ) of the second orifice passage 74, the second At the time of vibration input corresponding to the tuning frequency of the orifice passage 74, the switching passage 72 is maintained in a communicating state. In particular, when f ₂ <f ₃ , even if the resonance frequency slightly varies due to deformation or displacement of the valve portion 80 formed of an elastic body, the switching path is at the time of vibration input at a frequency corresponding to f _2. The blocking due to the anti-resonance 72 is avoided, and the intended vibration-proofing effect is effectively exhibited.

  Furthermore, in the present embodiment, since the substantial passage sectional area of the switching passage 72 provided with the valve portion 80 is larger than the passage sectional area of the second orifice passage 74, the second orifice The fluid flow in the passage is efficiently induced, and the vibration isolation effect by the second orifice passage 74 is advantageously exhibited.

  Further, since the switching passage 72 in which the valve portion 80 is disposed is formed on the pressure receiving chamber 60 side with respect to the second orifice passage 74, the operation of the valve portion 80 is caused by the contact of the flexible membrane 26. Problems such as obstruction are avoided. Moreover, since the opening of the second orifice passage 74 to the equilibrium chamber 62 is located on the outer peripheral side of the opening of the switching passage 72 to the pressure receiving chamber 60, the opening of the second orifice passage 74 is possible. The flexible film 26 is not blocked.

  In the engine mount 10 of the present embodiment, when a large negative pressure is applied to the pressure receiving chamber 60, the relief portion 82 of the switching valve 76 is sucked toward the pressure receiving chamber 60 and elastically deforms, whereby the upper partition member 34. It is separated from the contact protrusion 50. As a result, the short-circuit passage 66 is communicated, and the negative pressure in the pressure receiving chamber 60 is reduced or eliminated as soon as possible by the fluid flow through the short-circuit passage 66. As a result, cavitation due to pressure drop in the pressure receiving chamber 60 is prevented, and generation of abnormal noise is avoided.

  6 and 7 show an engine mount 90 as a second embodiment of the present invention. The engine mount 90 has a partition member 92. In addition, about the member and site | part substantially the same as the engine mount 10 of 1st embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol in a figure.

  More specifically, the partition member 92 has a structure in which a lid member 96 is overlaid on an upper surface of a thick, substantially disc-shaped partition member body 94 and a bottom member 98 is overlaid on the lower surface. In addition, a switching valve 126 (described later) is disposed between the partition member main body 94 and the lid member 96, and a relief means 144 (also described later) is disposed between the lid member 96 and the bottom member 98. ing.

  The partition member main body 94 is a hard member formed of metal, synthetic resin, or the like, and includes a peripheral groove 40 at the outer peripheral end. Furthermore, an accommodation recess 104 that is open to the upper surface with a substantially rectangular cross section is formed in the inner peripheral portion of the partition member main body 94, and is provided below the accommodation recess 104 and is larger than the accommodation recess 104. A communication recess 106 having an approximately rectangular cross section and opening on the lower surface is formed, and the accommodation recess 104 and the communication recess 106 are communicated with each other through the lower communication hole 108. Furthermore, an accommodation hole 110 penetrating up and down with a substantially constant circular cross section is formed in an inner peripheral portion of the partition member body 94 that is out of the accommodation recess 104 and the communication recess 106.

  The lid member 96 is hard like the partition member main body 94 and has a substantially disk shape, and is formed with an upper communication hole 112 and an upper short-circuit hole 114 penetrating in the thickness direction. On the other hand, the bottom member 98 is a hard, substantially disk-shaped member similar to the lid member 96, and has a substantially circular cross section that can be inserted into the accommodation hole 110 of the partition member main body 94, and a fitting protrusion that protrudes upward. 116 is formed, and a lower short-circuit hole 118 penetrating the fitting protrusion 116 in the axial direction is formed.

  A lid member 96 is overlaid on the upper surface of the partition member main body 94, and a bottom member 98 is overlaid on the lower surface. Thereby, the opening of the accommodation recess 104 is covered with the lid member 96, and the switching passage 120 that connects the pressure receiving chamber 60 and the communication recess 106 to each other is formed by the accommodation recess 104 and the upper and lower communication holes 112 and 108. Is formed.

  Further, a connection hole 122 is formed in a part of the peripheral wall of the communication recess 106, and the communication recess 106 is connected to the lower stage 44 of the circumferential groove 40 through the connection hole 122. A second orifice passage 124 is formed using the equilibrium chamber 62 side rather than the portion. As a result, the second orifice passage 124 and the switching passage 120 are connected in series via the communication recess 106, and the pressure receiving chamber 60 and the equilibrium chamber 62 communicate with the second orifice passage 124 and the switching passage 120. The recesses 106 communicate with each other.

  A switching valve 126 is disposed in the accommodation recess 104. The switching valve 126 is a rubber elastic body having a substantially long rectangular plate shape, and a slit 128 penetrating in the thickness direction is formed at a central portion.

  Further, the upper valve portion 130 is formed at one opening edge in the width direction and the upper buffer protrusion 132 is formed at the other opening edge in the width direction in the opening portion above the slit 128 in the switching valve 126. Has been. The upper valve portion 130 is a ridge that protrudes upward, and is gradually inclined toward the slit 128 toward the protruding tip, and gradually narrows toward the protruding tip. The upper shock-absorbing protrusion 132 is a protrusion that protrudes upward with a size smaller than that of the upper valve part 130, and is narrower toward the protruding tip. Furthermore, on the side opposite to the slit 128 with respect to the upper valve portion 130, an upper groove portion 134 that opens on the upper surface of the switching valve 126 is formed so as to extend along the base end of the upper valve portion 130.

  On the other hand, the lower opening of the slit 128 in the switching valve 126 is formed with a lower cushioning protrusion 136 that protrudes downward from one opening edge in the width direction and downward from the other opening edge in the width direction. A lower valve portion 138 is formed so as to protrude from the bottom. Further, on the opposite side of the lower valve portion 138 from the slit 128, a lower groove portion 140 opening on the lower surface of the switching valve 126 is formed so as to extend along the base end of the lower valve portion 138. The lower valve portion 138 has substantially the same structure as the upper valve portion 130, the lower buffer protrusion 136 has substantially the same structure as the upper buffer protrusion 132, and the lower groove portion 140 has substantially the same structure as the upper groove portion 134. Therefore, detailed description thereof is omitted here.

  The switching valve 126 is inserted into the housing recess 104, and a plate-like outer peripheral portion is sandwiched between the partition member main body 94 and the lid member 96. Further, the central portion of the switching valve 126 is disposed on the switching passage 120, and the upper valve portion 130 and the upper buffer projection 132 are inserted into the upper communication hole 112, and the lower valve portion 138 and the lower buffer projection 136 is inserted into the lower communication hole 108. As a result, the pressure receiving chamber 60 and the communication recess 106 are communicated with each other through the slit 128, and the switching passage 120 is substantially constituted by the slit 128 due to the arrangement of the switching valve 126, and is maintained in the communication state. . In the present embodiment, the support portion is constituted by a plate-shaped outer peripheral portion of the switching valve 126, and the valve portion is constituted by the upper valve portion 130 and the lower valve portion 138.

  Further, the resonance frequency of the switching passage 120 provided with the switching valve 126 is set to be higher than the tuning frequency of the second orifice passage 124. In addition, the passage sectional area of the switching passage 120 in the state in which the switching valve 126 is disposed is smaller than the passage sectional area of the second orifice passage 124.

  On the other hand, the upper opening of the accommodation hole 110 is covered with a lid member 96, communicated with the pressure receiving chamber 60 through the upper short-circuit hole 114, and the fitting protrusion of the bottom member 98 into which the lower opening of the accommodation hole 110 is inserted. The lid 116 is covered and communicated with the equilibrium chamber 62 through the lower short-circuit hole 118. Thus, a short-circuit passage 142 that connects the pressure receiving chamber 60 and the equilibrium chamber 62 to each other is formed by the accommodation hole 110 and the upper and lower short-circuit holes 114 and 118.

  A relief means 144 is provided on the short-circuit path 142. The relief means 144 has a structure in which a relief valve 146 made of a rubber elastic body is pressed against the projecting tip surface of the fitting projection 116 by a coil spring 148. The relief valve 146 has a circular block shape with a smaller diameter than the accommodation hole 110, and the lower part has a larger diameter than the upper part. The relief valve 146 is disposed in the accommodation hole 110, and the lower surface is the protruding tip of the fitting protrusion 116. It is superimposed on the surface in a non-fixed manner. Further, a coil spring 148 is disposed in the accommodation hole 110 and is interposed between the relief valve 146 and the lid member 96 in a compressed state, and the relief valve 146 is biased downward by the elasticity of the coil spring 148. ing. Accordingly, the lower short-circuit hole 118 penetrating the fitting protrusion 116 is covered by the relief valve 146, and the short-circuit passage 142 is blocked.

  The engine mount 90 including the partition member 92 having such a structure is a fluid that flows through the first orifice passage 64 when a low-frequency large-amplitude vibration corresponding to an engine shake is input in a mounted state on the vehicle. The anti-vibration effect based on the fluid action is exhibited.

  Furthermore, when a large amplitude vibration is input, due to the relative pressure difference between the pressure receiving chamber 60 and the equilibrium chamber 62, the valve portions 130 and 138 of the switching valve 126 are elastically deformed so as to contact the buffer protrusions 132 and 136, By closing the slit 128, the switching passage 120 is blocked. Thereby, the second orifice passage 124 is substantially blocked, and a large amount of fluid flowing through the first orifice passage 64 is secured. Since the upper and lower valve portions 130 and 138 are provided, the switching passage 120 is shut off regardless of whether positive pressure or negative pressure is applied to the pressure receiving chamber 60 by the input of large amplitude vibration. The vibration isolation effect by the orifice passage 64 is efficiently exhibited.

  Also in the engine mount 90 of the present embodiment, the switching passage 120 that is opened and closed by the switching valve 126 is provided in series outside the second orifice passage 124, so that the vibration damping effect by the second orifice passage 124 is achieved. The substantial cross-sectional area of the switching passage 120 can be set small without adversely affecting the switching passage 120. Therefore, the switching passage 120 can be quickly opened and closed by the valve portions 130 and 138 of the switching valve 126, and the vibration isolation effect by the first orifice passage 64 can be advantageously obtained.

  On the other hand, when the medium frequency small amplitude vibration corresponding to the idling vibration is input, the switching passage 120 constituted by the slit 128 is held in a communication state, so that it is based on the flow action of the fluid flowing through the second orifice passage 124. Anti-vibration effect is demonstrated. The first orifice passage 64 is substantially blocked by anti-resonance.

Further, since the switching valve 126 is disposed in the switching passage 120 outside the second orifice passage 124, the passage of the second orifice passage 124 is cut off as in the engine mount 10 of the first embodiment. A large area can be ensured, and an anti-vibration effect due to fluid flow can be advantageously obtained.

  In the switching valve 126 of the present embodiment, the valve portions 130 and 138 protrude from the partition member 92 through the communication holes 112 and 108, but the switching passage 120 in which the switching valve 126 is arranged is more than the second orifice passage 124. Further, by being connected to the pressure receiving chamber 60 side, interference of the flexible membrane 26 with the valve portions 130 and 138 is avoided.

  When a large negative pressure is applied to the pressure receiving chamber 60 due to the input of a large load, the relief valve 146 is suctioned and displaced toward the pressure receiving chamber 60 against the urging force of the coil spring 148. As a result, the lower surface of the relief valve 146 is separated from the protruding front end surface of the fitting protrusion 116 and the lower short-circuit hole 118 is communicated, so that the short-circuit passage 142 is switched to the communication state and the negative pressure of the pressure receiving chamber 60 is reduced. The pressure is reduced or eliminated by fluid flow through the short circuit passage 142.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, in the said embodiment, although the structure in which the short circuit path was formed was illustrated for the purpose of prevention of cavitation, the short circuit path is not essential and may be omitted. Furthermore, the relief part 82 of the switching valve 76 in the first embodiment for opening and closing the short circuit passage and the relief means 144 in the second embodiment can be omitted together with the short circuit passage.

  Moreover, in the said embodiment, although the structure where the 2nd orifice channel | path was formed using a part of 1st orifice channel | path was illustrated, a 1st orifice channel | path and a 2nd orifice channel | path are mutually independent. May be formed.

  Further, the switching passage in which the switching valve is disposed may be formed on the equilibrium chamber side of the second orifice passage and connected in series to the second orifice passage.

  In the above embodiment, the passage sectional area of the switching passage 72 in which the valve portion 80 of the switching valve 76 is disposed is larger than the passage sectional area of the second orifice passage 74. The passage sectional area of the disposed switching passage 72 may be smaller than the passage sectional area of the second orifice passage 74. According to this, the formation space of the switching passage 72 is reduced and the size of the switching passage 72 is reduced, and the switching passage 72 is blocked with high accuracy by elastic deformation of the switching valve 76 with respect to the input of the large amplitude vibration. The vibration isolation effect by the first orifice passage 64 is efficiently exhibited.

  Further, the valve portion may be configured to block the switching passage only when either positive pressure or negative pressure is applied to the pressure receiving chamber. As a result, it is possible to more effectively prevent cavitation noise and broaden the vibration isolation characteristics.

  The present invention can be suitably applied not only to a fluid-filled vibration isolator for automobiles but also to a fluid-filled vibration isolator used for motorcycles, railway vehicles, industrial vehicles, and the like. Furthermore, the scope of application of the present invention is not limited to engine mounts, but includes subframe mounts, body mounts, differential mounts, and the like.

10, 90: engine mount (fluid-filled vibration isolator), 12: first mounting member, 14: second mounting member, 16: rubber elastic body of the main body, 26: flexible membrane, 32, 92: partition 60, pressure receiving chamber, 62: equilibrium chamber, 64: first orifice passage, 72, 120: switching passage, 74, 124: second orifice passage, 76, 126: switching valve, 78: support, 80 : Valve part, 130: Upper valve part (valve part), 138: Lower valve part (valve part)

Claims (5)

The first mounting member and the second mounting member are elastically connected by the main rubber elastic body, and part of the wall portion is provided on both sides of the partition member supported by the second mounting member. Each of a pressure receiving chamber made of an elastic body and an equilibrium chamber made of a flexible membrane at a part of the wall is formed, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber. In addition, a first orifice passage and a second orifice passage communicating with the pressure receiving chamber and the equilibrium chamber are formed, and the tuning frequency of the second orifice passage is greater than the tuning frequency of the first orifice passage. In the fluid-filled vibration isolator that is also set to high frequency,
A switching passage connected in series with the second orifice passage is formed, and a switching valve is disposed in the switching passage in a manner to keep the switching passage in a communication state. The switching valve is switched according to the amplitude of the input vibration, and the resonance frequency of the switching passage provided with the switching valve is higher than the tuning frequency of the second orifice passage. while it is set to,
The switching valve is an elastic body integrally including a support portion supported by the partition member and a valve portion disposed in the switching passage, and is elastically deformed when a large amplitude vibration is input. A fluid-filled type vibration damping device characterized in that the fluid flow in the switching passage is blocked in both directions .   The fluid filled type vibration damping device according to claim 1, wherein the switching passage is formed on the pressure receiving chamber side of the second orifice passage.   The fluid-filled vibration isolator according to claim 1 or 2, wherein a passage sectional area of the switching passage provided with the switching valve is larger than a passage sectional area of the second orifice passage.   The fluid filled type vibration damping device according to any one of claims 1 to 3, wherein the switching passage provided with the switching valve is formed in an annular shape by extending the partition member in a circumferential direction.   The first orifice passage is formed by extending an outer peripheral portion of the partition member in the circumferential direction, the switching passage is communicated with an intermediate portion of the first orifice passage, and the second orifice passage is The fluid-filled type vibration damping device according to claim 1, wherein the fluid-filled type vibration damping device is formed by partially using the first orifice passage.

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