JP2007177975A - Vibration damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a leakage of a noise due to a knocking noise and a vibration to be generated by the collision of a passage control plate with the inside wall surface of a storage chamber when the vibration is transmitted. <P>SOLUTION: In the vibration damper 10, the core portion 102 of a plate shape lid fitting 50, which is fitted on the inner peripheral side of an outer cylinder fitting 14, and forms the storage chamber 80 between the inner peripheral side and a partition member 48 so as to be partitioned from a main liquid chamber 56 and a sub liquid chamber 58, is made of vibration absorbing alloy. As a result, even if the passage control plate 94 collides with the top portion 78 of the lid fitting 50 composing a part of the inner wall surface of the storage chamber 80 when the vibration is transmitted to the outer cylindrical fitting 14 or an inner cylindrical fitting 12, the vibration to be generated in the lid fitting 50 by the knocking noise to be generated between the passage control plate 94 and the lid fitting 50 and the impact force from the passage control plate 94 can be damped by means of the lid fitting 50. Therefore, the knocking noise and vibration can be effectively prevented from being transmitted to the members arranged around the lid fitting 50, such as the partition member 48, the outer cylinder fitting 14, and from leaking outside an apparatus via these peripheral members. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vibration isolator that is applied to, for example, an automobile, a general industrial machine, and the like and attenuates and absorbs vibration transmitted from a vibration generating unit such as an engine to a vibration receiving unit such as a vehicle body.

  In an automobile, an engine mount is disposed as an anti-vibration device between the engine and the vehicle body (frame). As an example of an anti-vibration device applied as such an engine mount, a liquid-sealed device shown in Patent Document 1 is known. In the vibration isolator shown in Patent Document 1, a liquid chamber space sealed from the outside is formed by an outer cylinder, a rubber elastic body, and a diaphragm, and the liquid chamber space is made of a rubber elastic body by a partition body. The main liquid chamber which is a part of the partition wall and the sub liquid chamber which is a diaphragm which is a part of the partition wall are partitioned, and the main liquid chamber and the sub liquid chamber are connected by an orifice which is a restriction passage.

  Here, the main liquid chamber, the sub liquid chamber, and the orifice are filled with a liquid such as water or polyalkylene glycol. The partition body is provided with an orifice which is a restricting passage for communicating the main liquid chamber and the sub liquid chamber on the outer peripheral side. In addition, a storage chamber which is a cylindrical space is provided inside the partition wall on the inner peripheral side of the orifice, and the storage chamber is connected to the main liquid chamber and the auxiliary chamber through first and second openings formed in the partition wall. Each communicates with the liquid chamber. In this vibration isolator, a movable plate formed in a disc shape with rubber or the like is accommodated as a flow control plate in the storage chamber, and this movable plate can vibrate along the amplitude direction of input vibration in the storage chamber. Has been.

  In the vibration isolator configured as described above, when the frequency of the input vibration is higher than a predetermined value, the orifice is clogged, but the movable plate vibrates in synchronization with the input vibration in the storage chamber. Since the liquid flows between the main liquid chamber and the sub liquid chamber through the storage chamber by alternately opening and closing the first and second openings, the rubber accompanying an increase in the liquid pressure in the main liquid chamber The rise of the dynamic spring constant of the elastic body can be suppressed, and the dynamic spring constant of the rubber elastic body is kept low even when such high frequency vibration is input, and the high frequency vibration is effectively prevented by elastic deformation of the rubber elastic body. Can absorb.

As the partition body used in the vibration isolator as described above, for example, a partition member formed in a disk shape with an aluminum alloy, a steel plate, etc., and a circular recess formed in the center of the upper surface, and a steel plate, etc. Some have a lid metal fitting formed into a thin disk shape. When assembling this partition wall body, a movable plate is inserted into the recess, and the outer peripheral portion (flange portion) of the partition member and the outer peripheral portion (flange portion) of the lid fitting are brought into contact with each other. Is inserted into the inner peripheral side of the outer cylinder member of the vibration isolator, and a part of the outer cylinder member is caulked to the inner peripheral side so that the outer peripheral edge of the partition member and the cover bracket is clamped. Are fixed to each other and fixed to a predetermined position in the outer cylinder member.
JP-A-1-193425

  However, in the vibration isolator as described above, the movable plate vibrates along the amplitude direction of the input vibration at the time of vibration input, and repeatedly collides with the inner wall surface of the storage chamber at a period corresponding to the frequency of the input vibration. For this reason, the impact force generated when the movable plate collides with the inner wall of the storage room generates a hitting sound and vibration in the lid fitting, and the hitting sound and vibration are transmitted from the lid fitting to surrounding parts such as the partition member and the outer cylinder fitting. May become abnormal noise and leak outside the device. In particular, if the vibration frequency of the movable plate matches the natural frequency of the vibration transmission system including the lid, the vibration of the movable plate is amplified by the resonance phenomenon and transmitted to the outside of the device. The level becomes higher.

  The object of the present invention is to take into account the above facts and effectively prevent the sound and vibration generated by collision of the flow control plate against the inner wall surface of the storage room when vibration is input and leak out of the apparatus as abnormal noise. An object of the present invention is to provide a vibration isolator that can be prevented.

  In order to solve the above-mentioned problem, a vibration isolator according to claim 1 of the present invention is formed in a cylindrical shape, and is connected to one of a vibration generating unit and a vibration receiving unit, and the first mounting member A second mounting member disposed on the inner peripheral side of the mounting member and connected to the other of the vibration generating unit and the vibration receiving unit, and disposed between the first mounting member and the second mounting member. A rubber elastic body, a liquid is sealed, a main liquid chamber whose internal volume changes as the rubber elastic body is deformed with the rubber elastic body as a part of a partition wall, a liquid is sealed, and the content is changed according to a change in liquid pressure A sub liquid chamber whose product can be expanded and contracted, a partition member that is fitted and inserted into an inner peripheral side of the first mounting member, and divides the main liquid chamber and the sub liquid chamber; A storage chamber partitioned from the main liquid chamber and the sub liquid chamber is formed between the mounting member and the inner peripheral side of the mounting member. Both are formed in the plate-shaped lid fitting formed from a damping alloy material, a restriction passage communicating the main liquid chamber and the secondary liquid chamber, the partition member and the lid fitting, respectively, and the storage chamber First and second openings communicating with the main liquid chamber and the sub liquid chamber, and disposed in the storage chamber, and vibrates in synchronization with the input vibration when the vibration is input, and the first opening And a flow control plate that alternately opens and closes the second opening.

  In the vibration isolator according to the first aspect, the plate is inserted into the inner peripheral side of the first mounting member and forms a storage chamber partitioned from the main liquid chamber and the sub liquid chamber between the partition member and the first mounting member. Flow control plate that has received pressure waves generated in the liquid in the main liquid chamber when vibration is input to the first mounting member or the second mounting member, since the shaped lid fitting is formed of a damping alloy material Even if the flow control plate vibrates along the amplitude direction of the input vibration and the flow control plate collides with the cover metal fitting that forms part of the inner wall surface of the storage chamber, Since vibration generated in the lid fitting due to the impact force from the flow control plate can be damped by the lid fitting made of a damping alloy having a high damping rate, such hitting sound and vibration are caused by the partition member, the first mounting member, etc. Is transmitted to the members arranged around the lid metal fittings, and through these peripheral members The leaking to 置外 portion can be effectively prevented.

  A vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein a thin-film damping layer having viscoelasticity is provided at least in a region in contact with the flow control plate in the lid fitting. It is formed.

  A vibration isolator according to claim 3 of the present invention is formed in a cylindrical shape and is connected to one of the vibration generating portion and the vibration receiving portion, and the inner peripheral side of the first mounting member. A second mounting member that is connected to the other of the vibration generating unit and the vibration receiving unit, a rubber elastic body that is disposed between the first mounting member and the second mounting member, and a liquid A main liquid chamber in which the internal volume changes as the rubber elastic body is deformed with the rubber elastic body as a part of the partition wall, and the liquid is enclosed, and the internal volume can be expanded and contracted according to a change in hydraulic pressure. A secondary liquid chamber, a partition member that is fitted on the inner peripheral side of the first mounting member and divides the main liquid chamber and the secondary liquid chamber, and an inner periphery of the first mounting member And a storage chamber partitioned from the main liquid chamber and the sub liquid chamber between the partition member and the damping steel plate. A plate-shaped lid fitting formed as above, a restriction passage communicating the main liquid chamber and the secondary liquid chamber, the partition member and the lid fitting, respectively, and the storage chamber as the main liquid chamber and the First and second openings communicated with the auxiliary liquid chamber, and disposed in the storage chamber, and vibrates in synchronization with the input vibration when vibration is input, and the first opening and the second opening. And a flow control plate that opens and closes alternately.

  In the vibration isolator according to the third aspect, the plate is inserted into the inner peripheral side of the first mounting member and forms a storage chamber partitioned from the main liquid chamber and the sub liquid chamber between the partition member and the first mounting member. The flow-control board which received the pressure wave which arises in the liquid in the main liquid chamber at the time of the vibration input to the 1st attachment member or the 2nd attachment member is formed by shape-like lid metal fittings using a damping steel plate as a raw material Even if the flow control plate oscillates along the amplitude direction of the input vibration and the flow control plate collides with the cover metal fitting that forms a part of the inner wall surface of the storage chamber, Since vibration can be damped by a lid made of a damping steel plate having a high attenuation rate, such a sound and vibration are arranged from the lid to the periphery of the lid, such as a partition member and a first mounting member. Effective to leak out of the device through these peripheral members. It can be prevented.

  The vibration isolator according to claim 4 of the present invention is the vibration isolator according to claim 3, wherein the lid metal fitting is provided with a vibration damping layer having viscoelasticity between two steel plates. It is characterized by being molded as a material.

  As described above, according to the vibration isolator of the present invention, when the vibration is input, the flow control plate collides with the inner wall surface of the storage chamber, and the sound and vibration generated by the noise are leaked out of the apparatus. It can be effectively prevented.

  Hereinafter, a vibration isolator according to an embodiment of the present invention will be described with reference to the drawings.

(Configuration of the embodiment)
FIG. 1 shows a vibration isolator according to an embodiment of the present invention. The vibration isolator 10 is applied as an engine mount that supports an engine that is a vibration generating unit in a vehicle such as an automobile to a vehicle body that is a vibration receiving unit. 1 indicates the axis of the apparatus, and the following description will be given with the direction along the axis S as the axial direction of the apparatus.

  As shown in FIG. 1, the vibration isolator 10 is disposed substantially coaxially on the inner cylinder fitting 12 formed in a substantially thick cylindrical shape connected to the engine side and on the outer peripheral side of the inner cylinder fitting 12. And a substantially thin cylindrical outer cylinder fitting 14 connected to the vehicle body side, and a rubber elastic body 16 made of rubber and disposed between the inner cylinder fitting 12 and the outer cylinder fitting 14 and serving as a main vibration absorber. . The inner cylinder fitting 12 has an upper end inserted into the outer cylinder fitting 14 and a lower end protruding through the opening on the lower end side of the outer cylinder fitting 14 to the lower side of the outer cylinder fitting 14. The outer tube fitting 14 is formed with an enlarged diameter portion 20 having a diameter larger than that of the lower end portion at the upper end portion with respect to the step portion 18 provided at the axially intermediate portion thereof. In addition, the outer tubular metal fitting 14 is formed with a tapered portion 22 whose diameter decreases in a tapered manner downward at the lower end portion thereof, and is bent at the upper end portion of the enlarged diameter portion 20 toward the inner peripheral side when the apparatus is assembled. A caulking portion 24 is formed.

  The vibration isolator 10 includes a substantially cup-shaped connecting tube 26 in which the lower end side of the outer tube fitting 14 is fitted and fixed, and a substantially bottomed cylindrical holder fitting 28 in which the lower end side of the connecting tube 26 is fitted and fixed. Is provided. The outer cylinder fitting 14 is inserted into the connecting cylinder 26 until the lower end thereof is in contact with the bottom plate portion of the connecting cylinder 26. A plurality of leg portions 30 and 32 are fixed to the outer peripheral surface of the holder metal fitting 28 by welding or the like, and bolts (not shown) are inserted through the connecting holes 33 formed on the distal ends of the leg portions 30 and 32. ), The holder fitting 28 is fastened and fixed to the vehicle body side. As a result, the outer cylinder fitting 14 is connected and fixed to the vehicle body via the connection cylinder 26 and the holder fitting 28.

  The lower end side of the inner cylinder fitting 12 protrudes to the lower side of the connection cylinder 26 through an opening 27 formed in the bottom plate portion of the connection cylinder 26, and an engine 34 is connected to the lower end portion of the inner cylinder fitting 12 by a bolt 34. The base end portion of the connecting bracket 36 is fastened and fixed. The bracket 36 extends to the outer peripheral side through an opening (not shown) formed in the side surface portion of the holder fitting 28, and the front end side of the bracket 36 is fastened and fixed to the engine (not shown) side by a bolt or the like. Is done. The base end portion of the bracket 36 is covered with a stopper rubber 38 formed in a tube shape, and the upper surface portion of the stopper rubber 38 is in pressure contact with the bottom plate portion of the connecting cylinder 26. Thereby, an excessive displacement along the axial direction of the bracket 36 is prevented, and the occurrence of a collision sound is also prevented when the bracket 36 collides with the connecting cylinder 26 or the holder fitting 28 due to an input of a large load.

  A bottom plate portion of an extension fitting 40 formed in a substantially cup shape that opens upward is fixed to the upper end surface of the inner cylinder fitting 12 by welding or the like. The extension fitting 40 has a tapered shape whose side plate portion has a diameter increasing from the bottom plate side toward the upper end side, and a ring-shaped flange member 42 is fixed to the upper end portion of the side plate portion by welding or the like. The extension fitting 40 extends from the upper end portion to the inner peripheral side. A plurality of runner holes 44 for filling the extension metal fitting 40 with vulcanized rubber, which is a molding material of the rubber elastic body 16, are formed in the side plate portion of the extension metal fitting 40.

  The rubber elastic body 16 is vulcanized and bonded to the upper end side of the inner cylinder fitting 12 inserted into the outer cylinder fitting 14 and the extension fitting 40, and is vulcanized and bonded to the lower end side of the outer cylinder fitting 14, respectively. The inner cylinder fitting 12 and the outer cylinder fitting 14 are connected elastically. Here, the rubber elastic body 16 is vulcanized and bonded to the outer peripheral surface of the inner cylindrical metal member 12 and the outer peripheral surface of the extension metal member 40, and is filled on the inner peripheral side of the extension metal member 40 through the runner hole 44. The inner peripheral surface and bottom surface of the extension fitting 40 and the lower surface of the flange member 42 are also vulcanized and bonded. Further, the rubber elastic body 16 is integrally formed with a thin covering portion 46 extending upward from the upper end portion on the outer peripheral side, and this covering portion 46 is formed on the upper end side on the inner peripheral surface of the outer cylinder fitting 14. The upper end side of the inner peripheral surface of the outer cylinder fitting 14 is covered.

  As shown in FIG. 1, a partition body 100 (see FIG. 3) formed in a generally thick disk shape is inserted on the upper side of the stepped portion 18 on the inner peripheral side of the outer cylindrical metal member 14. In addition, the outer peripheral edge portion on the lower surface of the partition body 100 is in contact with the step portion 18 through the covering portion 46. A cylindrical support cylinder 52 is fitted into the outer cylinder fitting 14 on the upper side of the partition wall body 100, and the lower end portion of the support cylinder 52 is in contact with the outer periphery of the upper surface of the partition wall body 100. In the outer cylinder fitting 14 into which the partition wall 100 and the support cylinder 52 are inserted, the caulking portion 24 having a constant inner and outer diameter is bent in a tapered shape toward the inner peripheral side. As a result, the partition wall 100 and the support cylinder 52 are fixed between the stepped portion 18 and the caulking portion 24 in the outer cylinder fitting 14.

  Here, an outer peripheral portion of a rubber diaphragm 54 formed in the shape of a convex ridge facing upward on the inner peripheral surface of the support cylinder 52 is vulcanized and bonded over the entire periphery. As shown in FIG. 2, the partition body 100 includes a partition member 48 formed in a substantially thick disk shape, and a substantially hat-shaped lid fitting 50 that is in close contact with the upper surface portion of the partition member 48. . The partition member 48 is formed by a method such as casting using a metal material such as an aluminum alloy as a raw material. The lid 50 is provided with a core portion 102 formed of a damping alloy plate as a raw material, and a damping layer 104 that covers the entire surface of the core portion 102.

  The damping alloy, which is a molding material of the core portion 102, has a sufficiently high attenuation rate compared to general metal materials such as carbon steel, stainless steel, and aluminum alloy that are used as the molding material of the lid fitting in the conventional vibration isolator. Specifically, for example, Mg alloy, Sirenalloy, Nitinol, Gentalloy, Mn—Cu alloy, Al—Zn alloy, flake graphite cast iron, high carbon piece having a logarithmic attenuation rate higher than 0.01 A graphite cast iron is used.

  In addition, as a molding material for the damping layer 104, a rubber material or a resin material having viscoelasticity is used. A rubber material such as NBR or NR can be used as the rubber material, but foamed rubber such as NBR-based foamed rubber having a larger loss factor for vibration than a general non-foamed rubber material is a molding material for the damping layer 104. Particularly suitable as. The resin material is not particularly limited, and examples of the resin material that can obtain a high loss factor include polyolefin resins such as polyethylene and polypropylene, polyester resins, polyurethane resins, and polyvinyl chloride resins. And ethylene acrylic copolymer resin. The thickness of the damping layer 104 is appropriately set in a range of about 0.5 mm to 1.0 mm according to the magnitude of the load input from the flow control plate 94, for example.

  In the vibration isolator 10, a liquid chamber space sealed from the outside is formed by the outer cylindrical metal member 14, the rubber elastic body 16, and the diaphragm 54, and the liquid chamber space is formed by separating the rubber elastic body 16 by the partition body 100. It is divided into a main liquid chamber 56 that is a part of the partition wall and a sub liquid chamber 58 that has the diaphragm 54 as a part of the partition wall. In the vibration isolator 10, the outside of the diaphragm 54 that forms a part of the partition wall of the sub liquid chamber 58 is an atmospheric space, so that the diaphragm 54 responds to changes in the liquid pressure in the sub liquid chamber 58. The liquid chamber 58 can be deformed so as to expand and contract the internal volume. Further, the main liquid chamber 56 expands and contracts with the elastic deformation of the rubber elastic body 16.

  The partition member 48 is provided with a concave groove 60 extending in the circumferential direction on the outer peripheral surface thereof. As shown in FIG. 2B, the groove portion 60 extends in a C shape along the circumferential direction with the axis S as the center, and the partition member 48 extends downward from one end portion of the groove portion 60. The lower side of the groove portion 60 is cut away to form the communication port 62, and the upper side of the groove portion 60 is cut upward from the other end portion of the groove portion 60 to form the communication port 64. Here, as shown in FIG. 1, the outer peripheral side of the groove portion 60 is closed by the inner peripheral surface of the outer cylindrical metal member 14 via the covering portion 46, so that the main liquid chamber 56 and the sub liquid chamber 58 are separated. An orifice 66 is formed as an elongated restricting passage for communication.

  The main liquid chamber 56, the sub liquid chamber 58 and the orifice 66 are filled with a liquid such as water or ethylene glycol, and this liquid can flow between the main liquid chamber 56 and the sub liquid chamber 58 through the orifice 66. It is said that. Here, the orifice 66 is set (tuned) so that its path length and cross-sectional area match the amplitude and frequency of the shake vibration.

  As shown in FIG. 2A, the partition member 48 is formed with a circular convex thick portion 68 at the central portion of the upper surface, and a circular concave portion 70 at the central portion of the thick portion 68. Is formed. In addition, the partition member 48 is formed with a circular concave relief portion 72 having a diameter larger than that of the concave portion 70 at the center of the lower surface, and a thickness between the top surface of the relief portion 72 and the bottom surface of the concave portion 70 is increased. A bottom plate portion 90 having a substantially constant length is provided. In the escape portion 72, the upper end portion of the extension fitting 40 and the rubber elastic body 16 is inserted while leaving a gap between the bottom plate portion 90 along the axial direction. Here, the gap between the bottom plate 90 and the extension fitting 40 and the rubber elastic body 16 is shown in FIG. 1 in a state where the engine is connected to the bracket 36 and a load resulting from the weight of the engine is input to the bracket 36. Since it is enlarged more than the state shown and has a sufficient width, the extension fitting 40 and the rubber elastic body 16 do not come into contact with the bottom plate portion 90 even if vibration is input.

  As shown in FIG. 2, the partition member 48 has a flat flange surface 84 on the outer peripheral side of the recess 70 on the upper surface thereof. The lid fitting 50 is formed with a circular convex partition 74 having an inner diameter substantially equal to the recess 70 of the partition member 48 at the center thereof, and extends from the lower end of the partition 74 to the outer peripheral side. An annular flange portion 76 is integrally formed. The outer diameter of the flange portion 76 is substantially equal to the outer diameter of the flange surface 84.

  In the case of using a vibration damping alloy other than cast iron as a raw material, the lid fitting 50 as described above is formed by forming the core portion 102 by press working and using cast iron such as flake graphite cast iron or high carbon flake graphite cast iron as a raw material. In this case, after the core portion 102 is formed by casting such as a precision casting method, a thin film-like resin material or rubber material is attached to the surface of the core portion 102 by a method such as welding or adhesion. Layer 104 is formed.

  The damping layer 104 may be formed by applying and spraying an irregular resin material or rubber material to the surface of the core portion 102 and then curing the irregular resin material or rubber material. The core portion 102 is inserted into the mold as an insert core, and the rubber layer is injected into the mold so that the damping layer 104 is vulcanized and bonded to the core portion 102 by vulcanization. good.

  When assembling the partition body 100 including the partition member 48 and the lid member 50, first, after the flow control plate 94 is inserted into the recess 70 of the partition member 48, the lid member 50 is placed on the partition member 48, The flange portion 76 of the lid fitting 50 is abutted against the flange surface 84 of the partition member 48. As a result, the assembly of the partition body 100 as a component in the apparatus is completed, and the support cylinder 52 to which the partition body 100 and the diaphragm 54 are vulcanized and bonded is fitted and inserted into the inner peripheral side of the outer cylinder fitting 14. The caulking portion 24 of the metal fitting 14 is caulked toward the inner peripheral side.

  As shown in FIG. 3A, in the partition wall 100, a thick disc having a substantially constant thickness along the axial direction between the recess 70 of the partition member 48 and the compartment 74 of the lid fitting 50. A space is formed, and this space serves as a storage chamber 80 partitioned from the main liquid chamber 56 and the sub liquid chamber 58. Further, as shown in FIG. 2B, the flange portion 76 of the lid fitting 50 is formed with a notch 82 that is cut out in a substantially rectangular shape from the outer peripheral end toward the inner peripheral side. The communication port 64 of the orifice 66 communicates with the auxiliary liquid chamber 58 through the notch 82.

  As shown in FIG. 2 (B), the lid 50 has a plurality of fan-shaped openings 88 on its top plate portion 78 whose dimensions extend in the circumferential direction from the inner periphery toward the outer periphery (this embodiment). In the form, 4 pieces are drilled. The storage chamber 80 communicates with the auxiliary liquid chamber 58 through the opening 88. The bottom plate portion 90 of the partition member 48 is also provided with a plurality of openings (four in this embodiment) having the same shape and opening area as the opening 88 of the lid fitting 50. The storage chamber 80 communicates with the main liquid chamber 56 through the opening 92.

  As shown in FIG. 3A, a distribution control plate 94 formed in a disc shape using rubber, resin or the like as a material is disposed in the storage chamber 80. The flow control plate 94 is formed in a thin disk shape having a substantially constant thickness as a whole, and its outer diameter is slightly smaller than the inner diameter of the storage chamber 80.

  The flow control plate 94 has a thickness PT (see FIG. 3A) shorter than a dimension ST (see FIG. 3A) along the axial direction of the storage chamber 80 by a predetermined dimension. Specifically, for example, the difference between the thickness PT of the flow control plate 94 and the thickness ST of the storage chamber 80 is shorter than the amplitude of the shake vibration that is a relatively low frequency vibration of the input vibration, And it is set so as to be longer than the amplitude of idle vibration which is relatively high frequency vibration. Accordingly, in the storage chamber 80, a gap having a width corresponding to the amplitude difference between the vibration in the low frequency region and the vibration in the high frequency region along the axial direction between the bottom plate portion 90 and the top plate portion 78 of the flow control plate 94. Is formed. Thereby, the flow control plate 94 stored in the storage chamber 80 can reciprocate (vibrate) along the axial direction with an amplitude corresponding to the amplitude difference between the low-frequency vibration and the high-frequency vibration.

(Operation of the embodiment)
Next, the operation and action of the vibration isolator 10 according to the embodiment of the present invention configured as described above will be described. In the vibration isolator 10, when the vibration is input from the engine or the vehicle body side, the rubber elastic body 16 which is the main vibration absorber is elastically deformed by the vibration. Thereby, the input vibration is attenuated and absorbed by the internal friction of the rubber elastic body 16 or the like.

  In the vibration isolator 10, when the rubber elastic body 16 is elastically deformed in synchronization with the vibration input at the time of vibration input from the engine or the vehicle body side, the internal volume of the main liquid chamber 56 is expanded and contracted and the hydraulic pressure is changed. Along with this change in liquid pressure, the liquid flows between the main liquid chamber 56 and the sub liquid chamber 58 through the orifice 66, and the flow control plate stored in the storage chamber 80 communicating with the main liquid chamber 56. 94, a hydraulic pressure (pressure wave) that periodically changes in synchronization with the input vibration acts, and the flow control plate 94 that has received this pressure wave vibrates along the axial direction in the storage chamber 80, The operation of abutting and separating the upper surface portion and the lower surface portion with respect to the top plate portion 78 of the lid fitting 50 and the bottom plate portion 90 of the partition member 48 is repeated.

  In the vibration isolator 10, when the flow control plate 94 moves downward and comes into contact with the bottom plate portion 90, the opening 92 that opens to the bottom plate portion 74 is closed by the lower surface portion of the flow control plate 94, and the flow control plate 94 is When spaced apart upward from the bottom plate portion 74, the opening 92 is opened. Further, when the flow control plate 94 moves upward and comes into contact with the top plate portion 78, the opening 88 opened to the top plate portion 78 is closed by the upper surface portion of the flow control plate 94.

  In the vibration isolator 10, when the frequency of the input vibration is low and the amplitude thereof is equal to or greater than a predetermined value, the liquid pressure in the main liquid chamber 56 substantially changes (increases and increases) with respect to the liquid pressure in the sub liquid chamber 58. The flow control plate 94 is in close contact with one of the bottom plate portion 90 and the top plate portion 78, and one of the openings 88 and 92 is closed and passes through the storage chamber 80. The liquid does not substantially flow between the main liquid chamber 56 and the sub liquid chamber 58, and the liquid flows between the main liquid chamber 56 and the sub liquid chamber 58 through only the orifice 66.

  Specifically, in the vibration isolator 10, when the frequency of the input vibration is equal to or lower than the frequency of the shake vibration (for example, 8 to 12 Hz), the liquid pressure in the main liquid chamber 56 becomes the liquid pressure in the sub liquid chamber 58. On the other hand, during the period of change (rise and fall), one of the openings 88 and 92 is closed by the flow control plate 94. Thus, when shake vibration is input, the liquid does not substantially flow between the main liquid chamber 56 and the sub liquid chamber 58 through the storage chamber 80, and the main liquid chamber 56 and the sub liquid chamber 56 are connected only through the orifice 66. Liquid flows between the liquid chamber 58 and each other.

  As a result, according to the vibration isolator 10, when the input vibration is a shake vibration, a resonance phenomenon (liquid column resonance) occurs in the liquid flowing through the orifice 66, and the input vibration is particularly reduced by the action of the liquid column resonance. It can attenuate effectively.

  Further, in the vibration isolator 10, when the frequency of the input vibration is higher than the frequency of the shake vibration and the amplitude thereof is small, for example, when the input vibration is an idle vibration (for example, 20 to 30 Hz), the vibration isolator 10 is suitable for the shake vibration. The orifice 66 tuned so as to become clogged, and it becomes difficult for the liquid to flow through the orifice 66. However, the flow control plate 94 vibrates in the storage chamber 80 in synchronization with the input vibration, so that the main liquid chamber 56. A gap is formed between the flow control plate 94 and one of the bottom plate portion 90 and the top plate portion 78 during a period in which the hydraulic pressure in the sub liquid chamber 58 substantially changes with respect to the hydraulic pressure. Since the portions 88 and 92 are substantially opened, the liquid flows through the storage chamber 80 between the main liquid chamber 56 and the sub liquid chamber 58.

  As a result, according to the vibration isolator 10, when the high frequency vibration having a frequency higher than the shake vibration is input, the orifice 66 becomes clogged and the liquid hardly flows through the orifice 66. Since the liquid in the main liquid chamber 56 flows out to the sub liquid chamber 58 through the storage chamber 80 so that the increase in the liquid pressure is suppressed, the dynamic spring of the device caused by the increase in the liquid pressure in the main liquid chamber 56 An increase in the constant can be suppressed, and the dynamic spring constant of the rubber elastic body 16 is kept low even when such high-frequency vibration (idle vibration or booming noise) is input, and high-frequency vibration is also generated by the elastic deformation of the rubber elastic body 16. Can absorb effectively.

  Further, in the vibration isolator 10, a plate-like shape that is fitted and inserted into the inner peripheral side of the outer cylindrical metal member 14 and forms a storage chamber 80 that is partitioned from the main liquid chamber 56 and the sub liquid chamber 58 with the partition member 48. Since the core portion 102 of the lid fitting 50 is formed using a damping alloy as a material, the pressure wave generated in the liquid in the main liquid chamber 56 is received when vibration is input to the outer cylinder fitting 14 or the inner cylinder fitting 12. Even if the flow control plate 94 vibrates along the amplitude direction (axial direction) of the input vibration and the flow control plate 94 collides with the top plate portion 78 of the lid fitting 50 constituting a part of the inner wall surface of the storage chamber 80, The core of the lid 50 made of a damping alloy having a high damping rate is used for the sound generated between the flow control plate 94 and the lid 50 and the vibration generated in the lid 50 due to the impact force from the flow control plate 94. Since it can be attenuated by the part 102, such a hitting sound and vibration are produced. Member 48, is transmitted to the members disposed around the cap member 50 such as outer tubular member 14, it can be effectively prevented from leaking outside the apparatus through these peripheral members.

  Further, in the vibration isolator 10, the thin vibration damping layer 104 having viscoelasticity is formed on the entire surface of the lid fitting 50 (core portion 102), so that the flow control plate 94 collides with the lid fitting 50. In addition, when the lid 50 receives an impact load from the flow control plate 94, the damping layer 104 is elastically deformed and the impact load is buffered, so that the impact generated when the flow control plate 94 collides with the lid 50 is applied. The sound pressure and volume of the sound can be reduced, and even if the lid fitting 50 vibrates due to the impact load from the flow control plate 94, the transmission of this vibration to the peripheral members can be blocked by the damping layer 104 having a high loss factor. Therefore, in addition to the vibration damping effect of the core portion 102, the vibration blocking effect by the damping layer 104 can also be effectively prevented from leaking to the outside of the apparatus through the peripheral member.

  In the vibration isolator 10 according to the present embodiment, the core portion 102 of the lid fitting 50 is formed of a vibration damping alloy, and the vibration damping layer 104 that covers the surface of the core portion 102 is a resin material having a large loss factor for vibration. Alternatively, when the level of noise that leaks out of the apparatus is low, the lid fitting 50 may be entirely made of a damping alloy and the damping layer 104 may be omitted. The core portion 102 of the metal fitting 50 is formed of a general metal material such as carbon steel, stainless steel, aluminum alloy or the like used as a molding material for the lid metal fitting in the conventional vibration isolator, and the core made of such a metal material. The damping layer 104 may be formed on the surface of the part.

  In addition, although the vibration damping layer 104 is formed on the entire surface of the lid 50, it is hardly a problem that the vibration sound leaks out of the apparatus, and it is only necessary to suppress the generation of the hitting sound. For example, if the damping layer 104 is formed only on the lower surface portion of the top plate portion 78 of the cover metal 50 facing the inside of the storage chamber 80, the sound generated when the flow control plate 94 collides with the top plate portion 78 is effectively prevented. Can be prevented.

(Modification of the embodiment)
FIG. 4 shows a modification of the partition body in the vibration isolator according to the embodiment of the present invention.

  Instead of the partition member 48 provided with the core portion 102 and the damping layer 104, the partition body 120 is provided with a lid fitting 122 formed (pressed) using a damping steel plate as a material. The lid fitting 122 is basically the same in shape and dimensions as the partition member 48, and similarly to the partition member 48, a compartment portion 124 is provided on the center side. An annular flange 126 is formed on the outer peripheral side.

  A known resin composite type is used as the damping steel plate 128 that is a molding material of the lid fitting 122, and the damping resin layer 128 is sandwiched between the two steel plates 130 along the thickness direction. 3 layer structure. The material of the steel plate 130 may be an alloy containing a metal other than iron, such as Ni or Ti, as a main component, in addition to those containing Fe as a main component, such as carbon steel and stainless steel.

  The resin material that is a molding material of the vibration damping resin layer 128 is not particularly limited, but a resin material that can obtain a high loss factor against vibration is suitable, for example, a polyolefin-based material such as polyethylene or polypropylene Resins, polyester resins, polyurethane resins, polyvinyl chloride resins, ethylene acrylic copolymer resins, and the like are preferably used.

  In the lid fitting 122 formed of the damping steel plate 128, when vibration and impact load are input, the damping resin layer 128 is deformed along with bending deformation caused by the vibration and impact load, so that vibration is caused by the damping resin layer 128. And the impact load is converted into thermal energy, and the vibration and impact load are attenuated and absorbed.

  When the lid fitting 122 shown in FIG. 4 is applied to the vibration isolator 10, in the vibration isolator 10, the main liquid chamber 56 and the partition member 48 are inserted into the inner peripheral side of the outer cylinder fitting 14. The plate-shaped lid fitting 122 forming the storage chamber 80 partitioned from the sub-liquid chamber 58 is formed using the damping steel plate 128 as a material, so that when vibration is input to the outer cylinder fitting 14 or the inner cylinder fitting 12, The flow control plate 94 that has received a pressure wave generated in the liquid in the main liquid chamber 56 vibrates along the amplitude direction (axial direction) of the input vibration, and the flow control plate 94 constitutes a part of the inner wall surface of the storage chamber 80. Even when it collides with the top plate portion 125 of the lid fitting 122, the sound and vibration generated in the lid fitting 122 due to the impact force from the flow control plate 94 are caused by the lid fitting 122 made of the damping steel plate 128 having a high attenuation rate. Because it can be effectively attenuated, Vibrations are transmitted from the cap member 122 partitioning member 48, the member disposed on the periphery of the cap member 122, such as the outer tubular member 14, it can be effectively prevented from leaking outside the apparatus through these peripheral members.

It is side surface sectional drawing which shows the structure of the vibration isolator which concerns on embodiment of this invention. It is the side sectional view and perspective view which show the state which decomposed | disassembled the partition body in the vibration isolator shown by FIG. It is side surface sectional drawing and a perspective view which show the structure of the partition body in the vibration isolator shown by FIG. It is side surface sectional drawing and a perspective view which show the modification of the partition body applicable to the vibration isolator shown by FIG.

Explanation of symbols

10 Antivibration device 12 Inner cylinder fitting (second mounting member)
14 Outer cylinder fitting (first mounting member)
16 Rubber elastic body 48 Partition member 50 Lid fitting 56 Main liquid chamber 58 Sub liquid chamber 66 Orifice 78 Top plate (lid fitting)
80 storage room 88 opening (second opening)
90 Bottom plate (partition member)
92 opening (first opening)
94 Distribution control plate 100 Partition body 102 Core part (damping alloy)
104 Damping layer 120 Partition body 122 Lid fitting 128 Damping steel plate 130 Steel plate 132 Damping layer

Claims (4)

A first mounting member formed in a cylindrical shape and connected to one of the vibration generating portion and the vibration receiving portion;
A second mounting member disposed on the inner peripheral side of the first mounting member and connected to the other of the vibration generating unit and the vibration receiving unit;
A rubber elastic body disposed between the first mounting member and the second mounting member;
A main liquid chamber in which a liquid is enclosed, and the internal volume of the rubber elastic body changes as the rubber elastic body is deformed with the rubber elastic body as a part of a partition;
A sub-liquid chamber in which liquid is enclosed and the internal volume can be expanded and contracted in accordance with a change in hydraulic pressure;
A partition member that is fitted on the inner peripheral side of the first mounting member and divides the main liquid chamber and the sub liquid chamber;
Inserted into the inner peripheral side of the first mounting member to form a storage chamber partitioned from the main liquid chamber and the sub liquid chamber between the partition member and formed from a damping alloy as a material Plate-shaped lid fittings,
A restricting passage communicating the main liquid chamber and the sub liquid chamber;
A first opening and a second opening formed in the partition member and the lid fitting, respectively, for communicating the storage chamber with the main liquid chamber and the sub liquid chamber;
A flow control plate that is arranged in the storage chamber and vibrates in synchronization with the input vibration when vibration is input, and alternately opens and closes the first opening and the second opening;
An anti-vibration device comprising:   2. The vibration isolator according to claim 1, wherein a thin-film damping layer having viscoelasticity is formed at least in a region in contact with the flow control plate in the lid fitting. A first mounting member formed in a cylindrical shape and connected to one of the vibration generating portion and the vibration receiving portion;
A second mounting member disposed on the inner peripheral side of the first mounting member and connected to the other of the vibration generating unit and the vibration receiving unit;
A rubber elastic body disposed between the first mounting member and the second mounting member;
A main liquid chamber in which a liquid is enclosed, and the internal volume of the rubber elastic body changes as the rubber elastic body is deformed with the rubber elastic body as a part of a partition;
A sub-liquid chamber in which liquid is enclosed and the internal volume can be expanded and contracted in accordance with a change in hydraulic pressure;
A partition member that is fitted on the inner peripheral side of the first mounting member and divides the main liquid chamber and the sub liquid chamber;
Inserted into the inner peripheral side of the first mounting member to form a storage chamber partitioned from the main liquid chamber and the sub liquid chamber between the partition member and formed from a damping steel plate Plate-shaped lid fittings,
A restricting passage communicating the main liquid chamber and the sub liquid chamber;
A first opening and a second opening formed in the partition member and the lid fitting, respectively, for communicating the storage chamber with the main liquid chamber and the sub liquid chamber;
A flow control plate that is disposed in the storage chamber and vibrates in synchronization with the input vibration when vibration is input, and alternately opens and closes the first opening and the second opening. Anti-vibration device.   4. The vibration isolator according to claim 3, wherein the lid metal fitting is formed from a vibration-damping steel plate in which a damping layer having viscoelasticity is interposed between two steel plates.

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