JP2021071126A - Fluid sealed-type vibration isolator - Google Patents

Abstract

To provide a fluid sealed-type vibration isolator having a novel structure which can obtain vibration isolation performance by a movable film structure, and also can prevent cavitation noise by a compact structure.SOLUTION: In a fluid sealed-type vibration isolator 10 in which a pressure receiving chamber 74 and a balance chamber 76 which are sealed with decompressive fluids are formed at both sides of a partitioning member 32, and a communication flow passage 80 for making the pressure receiving member 74 and the balance chamber 76 communicate with each other is formed, an accommodation region 54 is arranged in the partitioning member 32, and the communication flow passage 80 includes the accommodation region 54. A movable film 56 which is elastically deformable in a communication direction of the pressure receiving chamber 74 and the balance chamber 76 in the accommodation region 54 is arranged in the accommodation region 54, a compression coil spring 70 is arranged between a wall part of the accommodation region 54 at the pressure receiving chamfer 74 side and the movable film 56, and the movable film 56 is pressed to a wall part of the accommodation region 54 at the balance chamber 76 side by the compression coil spring 70.SELECTED DRAWING: Figure 1

Description

本発明は、自動車用のエンジンマウントなどに用いられる流体封入式防振装置に関するものである。 The present invention relates to a fluid-filled anti-vibration device used for an engine mount or the like for an automobile.

従来から、自動車のエンジンマウントなどに用いられる流体封入式防振装置において、防振効果を発揮する種々の構造が提案されており、１つとして可動膜の弾性変形による液圧伝達作用を利用する可動膜構造が知られている。例えば、特開２０１６−２１１５９０号公報（特許文献１）に示された液封防振装置は、主液室と副液室を相互に連通する貫通孔が、弾性仕切部材によって覆われた構造を有しており、主液室の液圧が弾性仕切部材の弾性変形によって副液室に伝達されて、主液室の高動ばね化が防止されることで、目的とする防振性能が発揮される。 Conventionally, various structures that exhibit anti-vibration effects have been proposed in fluid-filled anti-vibration devices used for automobile engine mounts, etc., and one of them utilizes the hydraulic pressure transmission action due to elastic deformation of the movable membrane. The movable membrane structure is known. For example, the liquid-sealed anti-vibration device shown in Japanese Patent Application Laid-Open No. 2016-21159 (Patent Document 1) has a structure in which a through hole communicating the main liquid chamber and the sub-liquid chamber with each other is covered with an elastic partition member. It has, and the hydraulic pressure of the main liquid chamber is transmitted to the auxiliary liquid chamber by the elastic deformation of the elastic partition member, and the high dynamic spring of the main liquid chamber is prevented, so that the desired vibration isolation performance is exhibited. Will be done.

ところで、流体封入式防振装置は、受圧室の内圧が大幅に低下する際に、キャビテーションによる異音が問題となる場合がある。そこで、特開２０１８−１５５３３２号公報（特許文献２）では、異音を低減する１つの方法として、受圧室の内圧が大幅に低下する場合に、受圧室と平衡室を連通させて、受圧室の負圧を低減乃至は解消するリリーフ機構が提案されている。特許文献２のリリーフ機構は、ゴムなどで形成された弁体が圧縮コイルスプリングによって仕切部材に押し付けられることで、仕切部材に設けられたリーク通路を受圧室側から塞ぐ構造とされている。そして、受圧室の内圧が低下すると、弁体が作用する負圧によって圧縮コイルスプリングの付勢力に抗して受圧室側へ移動して、リーク通路が解放されることから、リーク通路を通じた流体流動によって受圧室の負圧が速やかに低減される。 By the way, in the fluid-filled vibration isolator, when the internal pressure of the pressure receiving chamber drops significantly, abnormal noise due to cavitation may become a problem. Therefore, in Japanese Patent Application Laid-Open No. 2018-155332 (Patent Document 2), as one method of reducing abnormal noise, when the internal pressure of the pressure receiving chamber is significantly reduced, the pressure receiving chamber and the equilibrium chamber are communicated with each other to communicate with the pressure receiving chamber. A relief mechanism has been proposed that reduces or eliminates the negative pressure of. The relief mechanism of Patent Document 2 has a structure in which a valve body made of rubber or the like is pressed against a partition member by a compression coil spring to close a leak passage provided in the partition member from the pressure receiving chamber side. Then, when the internal pressure of the pressure receiving chamber decreases, the negative pressure acting on the valve body moves to the pressure receiving chamber side against the urging force of the compression coil spring, and the leak passage is released. Therefore, the fluid passing through the leak passage. The flow quickly reduces the negative pressure in the pressure receiving chamber.

特開２０１６−２１１５９０号公報Japanese Unexamined Patent Publication No. 2016-21159 特開２０１８−１５５３３２号公報JP-A-2018-155332

しかし、特許文献１に示されているような可動膜構造と、特許文献２に示されているようなリリーフ機構との両方を仕切部材に設けると、それら可動膜構造とリリーフ機構の配設スペースを確保するために、仕切部材ひいては流体封入式防振装置が大きくなり易い。また、昨今の車両におけるコンパクト化への要求によって流体封入式防振装置の外形寸法が厳しく制限される中で、それら可動膜構造とリリーフ機構の両方を設けようとすると、例えば可動膜の面積やリーク通路の通路断面積が十分に確保されず、目的とする性能を得ることが難しかった。 However, if both the movable membrane structure as shown in Patent Document 1 and the relief mechanism as shown in Patent Document 2 are provided in the partition member, the space for arranging the movable membrane structure and the relief mechanism is provided. In order to secure the above, the partition member and thus the fluid-filled vibration isolator tend to be large. In addition, while the external dimensions of fluid-filled anti-vibration devices are severely restricted by the recent demand for compactness in vehicles, if both the movable membrane structure and the relief mechanism are to be provided, for example, the area of the movable membrane and the area of the movable membrane It was difficult to obtain the desired performance because the passage cross-sectional area of the leak passage was not sufficiently secured.

本発明の解決課題は、可動膜構造による防振性能とキャビテーション異音の防止とを、コンパクトな構造で何れも実現することができる、新規な構造の流体封入式防振装置を提供することにある。 An object of the present invention is to provide a fluid-filled anti-vibration device having a novel structure capable of achieving both anti-vibration performance by a movable membrane structure and prevention of cavitation noise with a compact structure. is there.

以下、本発明を把握するための好ましい態様について記載するが、以下に記載の各態様は、例示的に記載したものであって、適宜に互いに組み合わせて採用され得るだけでなく、各態様に記載の複数の構成要素についても、可能な限り独立して認識及び採用することができ、適宜に別の態様に記載の何れかの構成要素と組み合わせて採用することもできる。それによって、本発明では、以下に記載の態様に限定されることなく、種々の別態様が実現され得る。 Hereinafter, preferred embodiments for grasping the present invention will be described, but each of the embodiments described below is described as an example, and not only can be appropriately combined with each other and adopted, but also described in each embodiment. The plurality of components of the above can also be recognized and adopted independently as much as possible, and can be appropriately adopted in combination with any of the components described in another embodiment. Thereby, in the present invention, various other aspects can be realized without being limited to the aspects described below.

第一の態様は、仕切部材の両側にそれぞれ非圧縮性流体が封入された受圧室と平衡室が形成されており、それら受圧室と平衡室を相互に連通する連通流路が形成されている流体封入式防振装置において、前記仕切部材の内部に収容領域が設けられて、前記連通流路が該収容領域を含んで構成されていると共に、該収容領域における該受圧室と該平衡室の連通方向で弾性変形可能とされた可動膜が該収容領域に配されており、該収容領域の該受圧室側の壁部と該可動膜との間に圧縮コイルスプリングが配されて、該可動膜が該圧縮コイルスプリングによって該収容領域の該平衡室側の壁部に押し当てられているものである。 In the first aspect, a pressure receiving chamber and an equilibrium chamber in which an incompressible fluid is sealed are formed on both sides of the partition member, and a communication flow path for communicating the pressure receiving chamber and the equilibrium chamber with each other is formed. In the fluid-filled vibration isolator, an accommodating region is provided inside the partition member, the communication flow path includes the accommodating region, and the pressure receiving chamber and the equilibrium chamber in the accommodating region are formed. A movable membrane that is elastically deformable in the communication direction is arranged in the accommodating area, and a compression coil spring is arranged between the wall portion of the accommodating area on the pressure receiving chamber side and the movable membrane, and the movable membrane is arranged. The membrane is pressed against the wall portion of the accommodating region on the equilibrium chamber side by the compression coil spring.

本態様に従う構造とされた流体封入式防振装置によれば、可動膜の微小変形によって連通流路における実質的な流体流動が許容されることから、流体の流動作用に基づく低動ばね化によって、振動絶縁による防振効果が発揮される。 According to the fluid-filled vibration isolator having a structure according to this embodiment, since the substantial fluid flow in the communication flow path is allowed due to the minute deformation of the movable membrane, the low dynamic spring based on the fluid flow action is used. , The anti-vibration effect due to vibration insulation is exhibited.

キャビテーションの発生が問題になるほどの圧力低下が受圧室において生じると、可動膜は、圧縮コイルスプリングの付勢力に抗して受圧室側へ移動し、収容領域の平衡室側の壁部から離れる。これにより、可動膜で覆われていた連通流路の平衡室側の開口が開放されて、連通流路を通じた流体流動がより大きな流量で許容される。その結果、平衡室から受圧室への連通流路を通じた流体流動が生じて、受圧室の圧力低下が速やかに緩和され、キャビテーションによる異音が低減乃至は回避される。 When a pressure drop that causes cavitation to occur becomes a problem in the pressure receiving chamber, the movable membrane moves toward the pressure receiving chamber side against the urging force of the compression coil spring and separates from the wall portion on the equilibrium chamber side of the accommodating region. As a result, the opening on the equilibrium chamber side of the communication flow path covered with the movable membrane is opened, and the fluid flow through the communication flow path is allowed at a larger flow rate. As a result, fluid flow is generated through the communication flow path from the equilibrium chamber to the pressure receiving chamber, the pressure drop in the pressure receiving chamber is quickly alleviated, and abnormal noise due to cavitation is reduced or avoided.

このように、振動入力時に弾性変形によって防振効果を発揮する可動膜が、連通流路の開口面積を制御して受圧室の圧力低下を抑制するリリーフ弁としても機能するようになっている。それ故、可動膜構造とリリーフ弁構造を各別に設ける必要がなく、仕切部材ひいては流体封入式防振装置のコンパクト化が図られる。 In this way, the movable membrane that exerts a vibration-proof effect by elastic deformation at the time of vibration input also functions as a relief valve that controls the opening area of the communication flow path and suppresses the pressure drop in the pressure receiving chamber. Therefore, it is not necessary to separately provide a movable membrane structure and a relief valve structure, and the partition member and thus the fluid-filled vibration isolator can be made compact.

第二の態様は、第一の態様に記載された流体封入式防振装置において、前記可動膜の外周部分に拘束部材が埋設状態で配されており、該拘束部材が、前記圧縮コイルスプリングの軸方向端面に重ね合わされる受け部と、該圧縮コイルスプリングの内周と外周の少なくとも一方に差し入れられる位置決め部とを、備えているものである。 In the second aspect, in the fluid-filled anti-vibration device described in the first aspect, a restraint member is embedded in an outer peripheral portion of the movable membrane, and the restraint member is a compression coil spring. It is provided with a receiving portion that is overlapped with the end face in the axial direction and a positioning portion that is inserted into at least one of the inner circumference and the outer circumference of the compression coil spring.

本態様に従う構造とされた流体封入式防振装置によれば、可動膜の外周部分に拘束部材が設けられていることにより、可動膜の外周部分において形状安定性の向上が図られる。それ故、圧縮コイルスプリングによって付勢された可動膜が、外周部分において収容領域の平衡室側の壁部へ安定して押し当てられて、連通流路の平衡室側の開口が可動膜によって有効に覆われる。 According to the fluid-filled vibration isolator having a structure according to this aspect, the shape stability is improved in the outer peripheral portion of the movable membrane by providing the restraining member on the outer peripheral portion of the movable membrane. Therefore, the movable membrane urged by the compression coil spring is stably pressed against the wall portion on the equilibrium chamber side of the accommodation region at the outer peripheral portion, and the opening on the equilibrium chamber side of the communication flow path is effective by the movable membrane. Covered in.

拘束部材が受け部を備えていることにより、圧縮コイルスプリングから可動膜へ及ぼされる力が効率よく伝達される。拘束部材が位置決め部を備えていることにより、圧縮コイルスプリングが可動膜に対して軸直角方向で位置決めされて、圧縮コイルスプリングによる付勢力が可動膜に対して適切に及ぼされる。更に、圧縮コイルスプリングが可動膜に対して軸直角方向で位置決めされることにより、可動膜が液圧の作用で受圧室側へ移動する際には、可動膜から圧縮コイルスプリングへ及ぼされる力によって圧縮コイルスプリングが軸方向に安定して圧縮変形される。 Since the restraining member includes the receiving portion, the force exerted from the compression coil spring to the movable membrane is efficiently transmitted. Since the restraining member includes the positioning portion, the compression coil spring is positioned in the direction perpendicular to the axis of the movable membrane, and the urging force of the compression coil spring is appropriately applied to the movable membrane. Further, since the compression coil spring is positioned in the direction perpendicular to the axis with respect to the movable film, when the movable film moves to the pressure receiving chamber side by the action of hydraulic pressure, the force applied from the movable film to the compression coil spring causes the movable film. The compression coil spring is stably compressed and deformed in the axial direction.

第三の態様は、第一又は第二の態様に記載された流体封入式防振装置において、前記可動膜において厚さ方向の弾性変形を許容される変形許容部が設けられており、該変形許容部の厚さ寸法に対して、該変形許容部の厚さ方向と直交する方向の外寸が６倍以上とされているものである。 In the third aspect, in the fluid-filled vibration isolator described in the first or second aspect, the movable membrane is provided with a deformation allowable portion that allows elastic deformation in the thickness direction, and the deformation is provided. The outer dimension in the direction orthogonal to the thickness direction of the deformation allowable portion is 6 times or more the thickness dimension of the allowable portion.

本態様に従う構造とされた流体封入式防振装置によれば、可動膜の変形許容部における厚さ寸法が厚さ直交方向の外寸よりも十分に小さくされて、変形許容部が薄肉とされていることから、変形許容部の厚さ方向の変形による液圧の伝達作用が有効に発揮される。また、変形許容部によって覆われる連通流路の平衡室側の開口を大きな面積で設けることができて、可動膜が収容領域の平衡室側の壁部から離れた状態において、連通流路を通じた流体の流動量を大きく得ることで、キャビテーションの発生がより効果的に防止される。 According to the fluid-filled anti-vibration device having a structure according to this embodiment, the thickness dimension of the deformation allowable portion of the movable membrane is sufficiently smaller than the outer dimension in the thickness orthogonal direction, and the deformation allowable portion is made thin. Therefore, the hydraulic pressure transmission action due to the deformation of the deformation allowable portion in the thickness direction is effectively exhibited. Further, an opening on the equilibrium chamber side of the communication flow path covered by the deformation allowable portion can be provided in a large area, and the movable membrane is passed through the communication flow path in a state of being separated from the wall portion on the equilibrium chamber side of the accommodation region. By obtaining a large amount of fluid flow, the occurrence of cavitation is more effectively prevented.

第四の態様は、第一〜第三の何れか１つの態様に記載された流体封入式防振装置において、前記可動膜の変形量を制限する変形制限部が、該可動膜に対して前記平衡室側に離れて設けられているものである。 In the fourth aspect, in the fluid-filled anti-vibration device according to any one of the first to third aspects, the deformation limiting portion that limits the amount of deformation of the movable film is the same with respect to the movable film. It is provided separately on the equilibrium chamber side.

本態様に従う構造とされた流体封入式防振装置によれば、受圧室の内圧が平衡室の内圧に対して高くなる場合に、可動膜の平衡室側への過大な変形が変形制限部によって防止されて、可動膜の耐久性の向上が図られる。また、変形制限部が可動膜から離れて配されることにより、可動膜の弾性変形による防振効果は有効に発揮される。 According to the fluid-filled vibration isolator having a structure according to this aspect, when the internal pressure of the pressure receiving chamber becomes higher than the internal pressure of the equilibrium chamber, excessive deformation of the movable membrane toward the equilibrium chamber is caused by the deformation limiting portion. This is prevented and the durability of the movable membrane is improved. Further, by arranging the deformation limiting portion away from the movable film, the anti-vibration effect due to the elastic deformation of the movable film is effectively exhibited.

本発明によれば、可動膜構造による防振性能とキャビテーション異音の防止とを、コンパクトな構造で何れも実現することができる。 According to the present invention, both anti-vibration performance and prevention of cavitation noise due to the movable membrane structure can be realized with a compact structure.

本発明の第一の実施形態としてのエンジンマウントを示す縦断面図Longitudinal section showing an engine mount as the first embodiment of the present invention. 図１に示すエンジンマウントを構成する仕切部材の斜視図Perspective view of the partition member constituting the engine mount shown in FIG. 図２に示す仕切部材の縦断面図Longitudinal sectional view of the partition member shown in FIG. 図１に示すエンジンマウントを構成する可動膜の斜視図Perspective view of the movable membrane constituting the engine mount shown in FIG. 図４に示す可動膜の縦断面図Longitudinal sectional view of the movable membrane shown in FIG. 図１に示すエンジンマウントにおいて受圧室に負圧が作用した状態を示す縦断面図A vertical sectional view showing a state in which a negative pressure is applied to a pressure receiving chamber in the engine mount shown in FIG.

以下、本発明の実施形態について、図面を参照しつつ説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１には、本発明に従う構造とされた流体封入式防振装置の第一の実施形態として、自動車用のエンジンマウント１０が示されている。エンジンマウント１０は、第一の取付部材１２と第二の取付部材１４が、本体ゴム弾性体１６によって弾性連結された構造を有している。以下の説明において、上下方向とは、原則として、マウント中心軸が延びる方向である図１中の上下方向を言う。 FIG. 1 shows an engine mount 10 for an automobile as a first embodiment of a fluid-filled vibration isolator having a structure according to the present invention. The engine mount 10 has a structure in which the first mounting member 12 and the second mounting member 14 are elastically connected by a main body rubber elastic body 16. In the following description, the vertical direction means, in principle, the vertical direction in FIG. 1, which is the direction in which the central axis of the mount extends.

第一の取付部材１２は、金属などで形成された部材とされている。第一の取付部材１２は、全体として略円柱形状とされていると共に、上端部には外周へ向けて突出するフランジ状部１８が設けられている。第一の取付部材１２は、中心軸上を軸方向に直線的に延びて、上面に開口するねじ穴２０を備えている。 The first mounting member 12 is a member made of metal or the like. The first mounting member 12 has a substantially cylindrical shape as a whole, and a flange-shaped portion 18 projecting toward the outer periphery is provided at the upper end portion. The first mounting member 12 includes a screw hole 20 that extends linearly in the axial direction on the central axis and opens on the upper surface.

第二の取付部材１４は、第一の取付部材１２と同様に金属などで形成された部材であって、薄肉大径の略円筒形状を有している。第二の取付部材１４は、軸方向の中間部分に段差が設けられており、段差よりも上側が下側よりも大径とされた段付き円筒形状とされている。 The second mounting member 14 is a member made of metal or the like like the first mounting member 12, and has a thin-walled large-diameter substantially cylindrical shape. The second mounting member 14 is provided with a step in the middle portion in the axial direction, and has a stepped cylindrical shape in which the upper side of the step has a larger diameter than the lower side.

第一の取付部材１２と第二の取付部材１４は、略同一中心軸上で軸方向にずれた位置に配されて、本体ゴム弾性体１６によって相互に弾性連結されている。本体ゴム弾性体１６は、全体として略円錐台形状を有しており、小径側の端部に第一の取付部材１２が固着されていると共に、大径側の端部の外周面に第二の取付部材１４の上部が固着されている。本体ゴム弾性体１６は、例えば、第一の取付部材１２と第二の取付部材１４を備える一体加硫成形品として形成される。 The first mounting member 12 and the second mounting member 14 are arranged at positions displaced in the axial direction on substantially the same central axis, and are elastically connected to each other by the main body rubber elastic body 16. The main body rubber elastic body 16 has a substantially truncated cone shape as a whole, the first mounting member 12 is fixed to the end portion on the small diameter side, and the second attachment member 12 is fixed to the outer peripheral surface of the end portion on the large diameter side. The upper part of the mounting member 14 of the above is fixed. The main body rubber elastic body 16 is formed as, for example, an integrally vulcanized molded product including a first mounting member 12 and a second mounting member 14.

本体ゴム弾性体１６は、大径側の軸方向端面に開口する凹所２２を備えている。凹所２２は、上底壁部が上下逆向きのすり鉢形状とされており、上方に向かって次第に小径となっている。また、本体ゴム弾性体１６は、凹所２２の外周側から下向きに延びるシールゴム層２４を備えている。シールゴム層２４は、本体ゴム弾性体１６に一体形成されており、第二の取付部材１４の下部の内周面に固着されている。なお、シールゴム層２４は、本体ゴム弾性体１６における凹所２２の開口部分の周壁よりも薄肉とされている。これにより、凹所２２の開口がシールゴム層２４の内周面よりも内周側に位置しており、シールゴム層２４の基端において本体ゴム弾性体１６に段差が形成されている。 The main body rubber elastic body 16 includes a recess 22 that opens on the axial end surface on the large diameter side. The recess 22 has a mortar shape in which the upper bottom wall portion is turned upside down, and the diameter gradually decreases upward. Further, the main body rubber elastic body 16 includes a seal rubber layer 24 extending downward from the outer peripheral side of the recess 22. The seal rubber layer 24 is integrally formed with the main body rubber elastic body 16 and is fixed to the inner peripheral surface of the lower portion of the second mounting member 14. The seal rubber layer 24 is thinner than the peripheral wall of the opening portion of the recess 22 in the main body rubber elastic body 16. As a result, the opening of the recess 22 is located on the inner peripheral side of the inner peripheral surface of the seal rubber layer 24, and a step is formed in the main body rubber elastic body 16 at the base end of the seal rubber layer 24.

第二の取付部材１４の下部には、可撓性膜２６が取り付けられている。可撓性膜２６は、薄肉のゴム膜であって、外周端部に金属等で形成された環状の固定部材２８が固着されている。そして、例えば固定部材２８が第二の取付部材１４の内周へ挿入された状態で、第二の取付部材１４に縮径加工が施されることにより、固定部材２８が第二の取付部材１４に取り付けられる。第二の取付部材１４と固定部材２８の間には、シールゴム層２４が介在しており、固定部材２８の外周面がシールゴム層２４を介して第二の取付部材１４の内周面に押し付けられることで、第二の取付部材１４と固定部材２８の間が流体密に封止されている。 A flexible film 26 is attached to the lower portion of the second attachment member 14. The flexible film 26 is a thin rubber film, and an annular fixing member 28 made of metal or the like is fixed to the outer peripheral end portion. Then, for example, in a state where the fixing member 28 is inserted into the inner circumference of the second mounting member 14, the second mounting member 14 is subjected to diameter reduction processing, so that the fixing member 28 becomes the second mounting member 14. Attached to. A seal rubber layer 24 is interposed between the second mounting member 14 and the fixing member 28, and the outer peripheral surface of the fixing member 28 is pressed against the inner peripheral surface of the second mounting member 14 via the seal rubber layer 24. As a result, the space between the second mounting member 14 and the fixing member 28 is fluid-tightly sealed.

可撓性膜２６が第二の取付部材１４に取り付けられることによって、本体ゴム弾性体１６と可撓性膜２６の間には、外部から流体密に隔てられた流体室３０が画成される。流体室３０には、水、エチレングリコール、シリコーン油などの非圧縮性流体が封入されている。流体室３０に封入される流体は、例示のものに限定されないが、例えば０．１Ｐａ・ｓ以下の低粘性流体であることが望ましい。 By attaching the flexible film 26 to the second attachment member 14, a fluid chamber 30 is defined between the main body rubber elastic body 16 and the flexible film 26 so as to be fluid-tightly separated from the outside. .. The fluid chamber 30 is filled with an incompressible fluid such as water, ethylene glycol, or silicone oil. The fluid enclosed in the fluid chamber 30 is not limited to the examples, but is preferably a low-viscosity fluid of, for example, 0.1 Pa · s or less.

流体室３０には、仕切部材３２が配されている。仕切部材３２は、図２，３に示すように、全体として略円板形状とされており、仕切部材本体３４と蓋部材３６を有している。 A partition member 32 is arranged in the fluid chamber 30. As shown in FIGS. 2 and 3, the partition member 32 has a substantially disk shape as a whole, and has a partition member main body 34 and a lid member 36.

仕切部材本体３４は、金属や合成樹脂などで形成された硬質の部材であって、全体として略有底円筒形状とされている。仕切部材本体３４の径方向の中央部分には、上面に開口する収容凹所３８が形成されている。収容凹所３８は、略円形断面で軸方向に延びていると共に、開口部分が段差状に大径とされている。収容凹所３８の底壁部には、軸方向に貫通する円形の下透孔４０が形成されている。収容凹所３８の周壁内面には、内周側へ向かって突出する位置決め突起４２が周方向の複数箇所に部分的に設けられている。位置決め突起４２は、収容凹所３８の下端から軸方向の途中まで軸方向に延びている。 The partition member main body 34 is a hard member made of metal, synthetic resin, or the like, and has a substantially bottomed cylindrical shape as a whole. A storage recess 38 that opens on the upper surface is formed in the central portion of the partition member main body 34 in the radial direction. The storage recess 38 has a substantially circular cross section and extends in the axial direction, and the opening portion has a large diameter in a stepped shape. A circular lower through hole 40 penetrating in the axial direction is formed in the bottom wall portion of the storage recess 38. On the inner surface of the peripheral wall of the accommodating recess 38, positioning protrusions 42 projecting toward the inner peripheral side are partially provided at a plurality of locations in the circumferential direction. The positioning protrusion 42 extends axially from the lower end of the accommodating recess 38 to the middle of the axial direction.

仕切部材本体３４の外周端部には、外周面に開口しながら周方向へ螺旋状に延びる周溝４４が形成されている。本実施形態の周溝４４は、２周に満たない長さで周方向に延びているが、周溝４４の周方向長さは、１周に満たなくても良いし、２周以上であっても良い。 A peripheral groove 44 is formed at the outer peripheral end of the partition member main body 34 so as to spirally extend in the circumferential direction while opening on the outer peripheral surface. The peripheral groove 44 of the present embodiment extends in the circumferential direction with a length of less than two laps, but the circumferential length of the peripheral groove 44 does not have to be less than one lap, and is two or more laps. You may.

仕切部材本体３４は、周溝４４の一方の端部において上端部の外周部分が切り欠かれており、この切欠きによって後述する第一のオリフィス通路７８の一方の端部を構成する第一の連通口４６が形成されている。また、仕切部材本体３４は、周溝４４の他方の端部において下端部の外周部分が切り欠かれており、この切欠きによって後述する第一のオリフィス通路７８の他方の端部を構成する第二の連通口４８が形成されている。 The partition member main body 34 has a notch at the outer peripheral portion of the upper end portion at one end of the peripheral groove 44, and the first notch constitutes one end of the first orifice passage 78 described later. A communication port 46 is formed. Further, the partition member main body 34 has a notch at the outer peripheral portion of the lower end portion at the other end portion of the peripheral groove 44, and this notch constitutes the other end portion of the first orifice passage 78 described later. Two communication ports 48 are formed.

蓋部材３６は、略円環板形状とされており、径方向の中央部分を軸方向に貫通する円形の上透孔５０が形成されている。蓋部材３６は、下面に突出する環状の嵌合突部５２を備えている。嵌合突部５２の内周面は、上透孔５０の内周面よりも大径とされており、上透孔５０の開口周縁部と嵌合突部５２とによって、後述する圧縮コイルスプリング７０の上端部が位置決めされる。 The lid member 36 has a substantially annular plate shape, and a circular upper through hole 50 that penetrates the central portion in the radial direction in the axial direction is formed. The lid member 36 includes an annular fitting protrusion 52 that projects to the lower surface. The inner peripheral surface of the fitting protrusion 52 has a larger diameter than the inner peripheral surface of the upper through hole 50, and the compression coil spring described later is provided by the opening peripheral edge of the upper through hole 50 and the fitting protrusion 52. The upper end of 70 is positioned.

蓋部材３６が仕切部材本体３４の収容凹所３８の開口部分に取り付けられることにより、仕切部材３２が構成されている。本実施形態では、嵌合突部５２を含む蓋部材３６の外周面が収容凹所３８の開口部分に嵌め合わされて固定されている。仕切部材３２の内部には、仕切部材本体３４における収容凹所３８の底壁部と蓋部材３６との間に収容領域５４が形成されており、上透孔５０と下透孔４０が収容領域５４に連通されている。 The partition member 32 is formed by attaching the lid member 36 to the opening portion of the accommodating recess 38 of the partition member main body 34. In the present embodiment, the outer peripheral surface of the lid member 36 including the fitting protrusion 52 is fitted and fixed to the opening portion of the accommodating recess 38. Inside the partition member 32, a storage area 54 is formed between the bottom wall portion of the storage recess 38 in the partition member main body 34 and the lid member 36, and the upper through hole 50 and the lower through hole 40 are the storage areas. It is communicated with 54.

収容領域５４には、可動膜５６が配されている。可動膜５６は、図４，５に示すように、浅底の略有底円筒形状とされており、外周端部が上側へ突出する突出部５８とされている。可動膜５６の下面は、内周部分が浅底の凹状面５９とされていると共に、外周端部において下方へ向けて突出する環状のリップ６０が設けられている。 A movable membrane 56 is arranged in the accommodating area 54. As shown in FIGS. 4 and 5, the movable film 56 has a shallow-bottomed substantially bottomed cylindrical shape, and has a protruding portion 58 whose outer peripheral end portion projects upward. The lower surface of the movable film 56 is provided with a concave surface 59 having a shallow inner peripheral portion and an annular lip 60 projecting downward at the outer peripheral end portion.

可動膜５６の外周部分には、図５に示すように、拘束部材６２が埋設状態で設けられている。拘束部材６２は、金属や合成樹脂で形成された硬質の部材とされている。拘束部材６２は、略円環板形状の受け部６４と、受け部６４の外周端部から上側へ突出する略円筒形状の位置決め部６６とを、備えている。本実施形態の拘束部材６２は、プレス金具で構成されており、受け部６４と位置決め部６６が金属素板のプレス加工によって一体形成されている。そして、可動膜５６の外周部分は、拘束部材６２によって弾性変形量を制限されて、形状安定性の向上が図られている。可動膜５６における拘束部材６２を外れた内周部分は、厚さ方向の変形を比較的自由に許容される薄肉膜状の変形許容部６８とされている。 As shown in FIG. 5, a restraining member 62 is provided in an embedded state on the outer peripheral portion of the movable film 56. The restraint member 62 is a hard member made of metal or synthetic resin. The restraint member 62 includes a substantially annular plate-shaped receiving portion 64 and a substantially cylindrical positioning portion 66 projecting upward from the outer peripheral end portion of the receiving portion 64. The restraint member 62 of the present embodiment is composed of a press fitting, and the receiving portion 64 and the positioning portion 66 are integrally formed by pressing a metal base plate. The outer peripheral portion of the movable film 56 is limited in the amount of elastic deformation by the restraining member 62 to improve the shape stability. The inner peripheral portion of the movable film 56 that is detached from the restraint member 62 is a thin-walled film-like deformation permitting portion 68 that allows deformation in the thickness direction relatively freely.

可動膜５６における変形許容部６８の外寸Ｒは、変形許容部６８の厚さ寸法Ｔに対して６倍以上とされている。このように、可動膜５６の変形許容部６８は十分に薄肉とされており、変形許容部６８の厚さ方向の弾性変形が十分に許容されている。なお、本実施形態において、可動膜５６における変形許容部６８の外寸は、拘束部材６２における受け部６４の内径寸法と略同じとされている。 The outer dimension R of the deformation allowable portion 68 of the movable film 56 is set to be 6 times or more the thickness dimension T of the deformation allowable portion 68. As described above, the deformation allowable portion 68 of the movable film 56 is sufficiently thin, and the elastic deformation of the deformation allowable portion 68 in the thickness direction is sufficiently allowed. In the present embodiment, the outer dimension of the deformation allowable portion 68 of the movable film 56 is substantially the same as the inner diameter dimension of the receiving portion 64 of the restraining member 62.

可動膜５６は、図３に示すように、仕切部材３２の収容領域５４に配されている。可動膜５６は、収容領域５４と略同一中心軸上に配されている。可動膜５６の軸方向寸法は、収容領域５４の軸方向の内法よりも小さくされている。可動膜５６は、収容領域５４の上壁部である蓋部材３６に対して、下方に離れて配されている。可動膜５６の突出部５８の上面と蓋部材３６の嵌合突部５２の下面との対向面間には、所定のスペースが設けられている。可動膜５６の外径寸法は、収容領域５４の軸直角方向の内法よりも小さくされており、可動膜５６の外周面と収容領域５４の外周面との間には、隙間６９が設けられている。本実施形態の隙間６９は全周に亘って設けられているが、周方向で部分的に隙間６９が設けられていても良い。収容領域５４の周壁内面における位置決め突起４２の形成部分では、隙間６９が小さくなっており、可動膜５６の軸直角方向に移動可能な距離が制限されている。 As shown in FIG. 3, the movable film 56 is arranged in the accommodating area 54 of the partition member 32. The movable film 56 is arranged on a central axis substantially the same as the accommodation area 54. The axial dimension of the movable film 56 is smaller than the axial inner method of the accommodating area 54. The movable film 56 is arranged downward with respect to the lid member 36 which is the upper wall portion of the accommodating area 54. A predetermined space is provided between the upper surface of the protruding portion 58 of the movable film 56 and the lower surface of the fitting protrusion 52 of the lid member 36. The outer diameter of the movable film 56 is smaller than the inner diameter of the accommodation area 54 in the direction perpendicular to the axis, and a gap 69 is provided between the outer peripheral surface of the movable film 56 and the outer peripheral surface of the accommodation area 54. ing. Although the gap 69 of the present embodiment is provided over the entire circumference, the gap 69 may be partially provided in the circumferential direction. In the portion where the positioning projection 42 is formed on the inner surface of the peripheral wall of the accommodating region 54, the gap 69 is small, and the distance that the movable film 56 can move in the direction perpendicular to the axis is limited.

収容領域５４に収容された可動膜５６の上側には、圧縮コイルスプリング７０が配されている。圧縮コイルスプリング７０は、収容領域５４の上壁部を構成する蓋部材３６と可動膜５６との対向面間に圧縮された状態で配されている。これにより、可動膜５６には、圧縮コイルスプリング７０の弾性に基づいた下向きの付勢力が及ぼされており、可動膜５６が下透孔４０の周壁を構成する収容領域５４の下壁部に押し当てられている。可動膜５６と圧縮コイルスプリング７０が同一中心軸上に配されて、可動膜５６が圧縮コイルスプリング７０の弾性によって下向きに付勢されていることから、可動膜５６が全周に亘って収容領域５４の下壁部に安定して押し当てられる。また、圧縮コイルスプリング７０の伸縮変形を伴う可動膜５６の軸方向の移動がスムーズに且つ安定して生じる。圧縮コイルスプリング７０の下面は、可動膜５６における拘束部材６２の受け部６４が固着された部分に重ね合わされており、圧縮コイルスプリング７０の弾性による下向きの力が、可動膜５６へ効率的に伝達される。 A compression coil spring 70 is arranged on the upper side of the movable film 56 housed in the storage area 54. The compression coil spring 70 is arranged in a compressed state between the facing surfaces of the lid member 36 forming the upper wall portion of the accommodating area 54 and the movable film 56. As a result, a downward urging force based on the elasticity of the compression coil spring 70 is applied to the movable film 56, and the movable film 56 pushes the movable film 56 against the lower wall portion of the accommodating area 54 forming the peripheral wall of the lower through hole 40. It is guessed. Since the movable film 56 and the compression coil spring 70 are arranged on the same central axis and the movable film 56 is urged downward by the elasticity of the compression coil spring 70, the movable film 56 covers the entire circumference of the accommodation area. It is stably pressed against the lower wall portion of 54. Further, the axial movement of the movable film 56 accompanied by the expansion and contraction deformation of the compression coil spring 70 occurs smoothly and stably. The lower surface of the compression coil spring 70 is superposed on the portion of the movable film 56 to which the receiving portion 64 of the restraining member 62 is fixed, and the downward force due to the elasticity of the compression coil spring 70 is efficiently transmitted to the movable film 56. Will be done.

可動膜５６は、下方に突出するリップ６０が収容領域５４の下壁部に押し当てられており、リップ６０において収容領域５４の下壁部に強く当接している。可動膜５６の外周部分は、下透孔４０よりも外周側において、収容領域５４の下壁部に全周に亘って押し当てられており、下透孔４０の上側（収容領域５４側）が可動膜５６の変形許容部６８によって覆蓋されている。 In the movable film 56, the lip 60 projecting downward is pressed against the lower wall portion of the accommodating area 54, and is strongly in contact with the lower wall portion of the accommodating area 54 at the lip 60. The outer peripheral portion of the movable film 56 is pressed against the lower wall portion of the accommodating area 54 on the outer peripheral side of the lower through hole 40 over the entire circumference, and the upper side of the lower through hole 40 (accommodation area 54 side) is pressed. It is covered with a deformation allowable portion 68 of the movable film 56.

下透孔４０の周囲において、収容領域５４の下壁部は、拘束部材６２を外れた可動膜５６の変形許容部６８に対して、下側に離れた位置で対向して配されている。これにより、可動膜５６の下側への弾性変形量が、可動膜５６と下透孔４０の周囲との当接によって制限される。このように、可動膜５６の下側への弾性変形量を制限する変形制限部７２が、収容領域５４の下壁部における下透孔４０の周囲に設けられている。変形許容部６８の下面が凹状面５９によって凹んだ形状とされていることにより、拘束部材６２を備えた可動膜５６の外周部分が収容領域５４の下壁部に押し当てられると共に、可動膜５６の変形許容部６８が収容領域５４の下壁部で構成された変形制限部７２から上方に離れている。尤も、例えば、収容領域５４の下壁部の内周部分に上向きに開口する凹所を設けるなどして、可動膜５６の外周部分と収容領域５４の下壁部を当接させつつ、収容領域５４の下壁部を可動膜５６の内周部分（変形許容部６８）に対して下方に離れて位置させることもできる。この場合には、可動膜５６の下面が凹状とされていなくても、変形制限部７２を可動膜５６の下面に対して下方に離隔位置させることができる。 Around the lower through hole 40, the lower wall portion of the accommodating region 54 is arranged so as to face the deformation allowable portion 68 of the movable film 56 that has come off the restraining member 62 at a position distant from the lower side. As a result, the amount of elastic deformation of the movable film 56 downward is limited by the contact between the movable film 56 and the periphery of the lower through hole 40. As described above, the deformation limiting portion 72 that limits the amount of elastic deformation downward of the movable film 56 is provided around the lower through hole 40 in the lower wall portion of the accommodating area 54. Since the lower surface of the deformation allowable portion 68 is recessed by the concave surface 59, the outer peripheral portion of the movable film 56 provided with the restraining member 62 is pressed against the lower wall portion of the accommodating area 54, and the movable film 56 is pressed. The deformation permitting portion 68 of the above is separated upward from the deformation limiting portion 72 formed by the lower wall portion of the accommodating area 54. However, for example, by providing a recess that opens upward in the inner peripheral portion of the lower wall portion of the accommodating region 54, the accommodating region is brought into contact with the outer peripheral portion of the movable membrane 56 and the lower wall portion of the accommodating region 54. The lower wall portion of the 54 may be positioned downwardly apart from the inner peripheral portion (deformation allowable portion 68) of the movable film 56. In this case, even if the lower surface of the movable film 56 is not concave, the deformation limiting portion 72 can be positioned downward with respect to the lower surface of the movable film 56.

圧縮コイルスプリング７０の上端部は、蓋部材３６の嵌合突部５２の内周に差し入れられており、蓋部材３６に対して位置決めされている。圧縮コイルスプリング７０の下端部は、拘束部材６２の位置決め部６６に固着された可動膜５６の突出部５８の内周に差し入れられており、可動膜５６に対して位置決めされている。 The upper end of the compression coil spring 70 is inserted into the inner circumference of the fitting protrusion 52 of the lid member 36, and is positioned with respect to the lid member 36. The lower end of the compression coil spring 70 is inserted into the inner circumference of the protruding portion 58 of the movable film 56 fixed to the positioning portion 66 of the restraint member 62, and is positioned with respect to the movable film 56.

このような可動膜５６と圧縮コイルスプリング７０を収容した仕切部材３２は、図１に示すように、流体室３０に配されている。即ち、仕切部材３２は、流体室３０において軸直角方向で広がっており、仕切部材３２の外周面がシールゴム層２４を介して第二の取付部材１４の内周面に押し付けられる。なお、仕切部材３２は、例えば、シールゴム層２４で覆われた第二の取付部材１４の内周に挿入された状態で、第二の取付部材１４に縮径加工が施されることによって、第二の取付部材１４に取り付けられる。 As shown in FIG. 1, the partition member 32 accommodating the movable film 56 and the compression coil spring 70 is arranged in the fluid chamber 30. That is, the partition member 32 extends in the direction perpendicular to the axis in the fluid chamber 30, and the outer peripheral surface of the partition member 32 is pressed against the inner peripheral surface of the second mounting member 14 via the seal rubber layer 24. The partition member 32 is, for example, inserted into the inner circumference of the second mounting member 14 covered with the seal rubber layer 24, and the second mounting member 14 is subjected to diameter reduction processing. It is attached to the second attachment member 14.

第二の取付部材１４と仕切部材３２の間にシールゴム層２４が介在することによって、仕切部材３２が第二の取付部材１４に流体密に組み付けられており、流体室３０が仕切部材３２を挟んだ上下両側に二分されている。即ち、仕切部材３２の上側には、壁部の一部が本体ゴム弾性体１６によって構成されて、振動入力時に内圧変動が惹起される受圧室７４が設けられる。仕切部材３２の下側には、壁部の一部が可撓性膜２６によって構成されて、容積変化が許容される平衡室７６が設けられる。受圧室７４と平衡室７６は、何れも流体室３０の一部であることから、それぞれ非圧縮性流体が封入されている。 By interposing the seal rubber layer 24 between the second mounting member 14 and the partition member 32, the partition member 32 is fluidly assembled to the second mounting member 14, and the fluid chamber 30 sandwiches the partition member 32. However, it is divided into upper and lower sides. That is, on the upper side of the partition member 32, a pressure receiving chamber 74 is provided in which a part of the wall portion is composed of the main body rubber elastic body 16 and the internal pressure fluctuation is caused at the time of vibration input. On the lower side of the partition member 32, an equilibrium chamber 76 is provided in which a part of the wall portion is formed of a flexible film 26 and a volume change is allowed. Since both the pressure receiving chamber 74 and the equilibrium chamber 76 are a part of the fluid chamber 30, incompressible fluid is sealed therein.

仕切部材３２の外周面がシールゴム層２４で覆われた第二の取付部材１４によって流体密に覆われることにより、仕切部材３２に設けられた周溝４４の外周側の開口部が流体密に閉塞されている。また、周溝４４の両端部は、第一の連通口４６によって受圧室７４に連通されていると共に、第二の連通口４８によって平衡室７６に連通されている。これにより、受圧室７４と平衡室７６を相互に連通する第一のオリフィス通路７８が、周溝４４と第一，第二の連通口４６，４８とを利用して設けられている。第一のオリフィス通路７８は、通路断面積の通路長さに対する比などによって、流動流体の共振周波数であるチューニング周波数が調節されている。第一のオリフィス通路７８の具体的なチューニング周波数は、特に限定されるものではないが、例えば、エンジンシェイクに相当する数Ｈｚ程度の低周波に設定される。 The outer peripheral surface of the partition member 32 is fluid-tightly covered by the second mounting member 14 covered with the seal rubber layer 24, so that the opening on the outer peripheral side of the peripheral groove 44 provided in the partition member 32 is fluid-tightly closed. Has been done. Further, both ends of the peripheral groove 44 are communicated with the pressure receiving chamber 74 by the first communication port 46, and are communicated with the equilibrium chamber 76 by the second communication port 48. As a result, the first orifice passage 78 that communicates the pressure receiving chamber 74 and the equilibrium chamber 76 with each other is provided by utilizing the peripheral groove 44 and the first and second communication ports 46 and 48. In the first orifice passage 78, the tuning frequency, which is the resonance frequency of the flowing fluid, is adjusted by the ratio of the passage cross-sectional area to the passage length. The specific tuning frequency of the first orifice passage 78 is not particularly limited, but is set to, for example, a low frequency of about several Hz corresponding to an engine shake.

仕切部材３２の上透孔５０が受圧室７４に開口していると共に、下透孔４０が平衡室７６に開口しており、収容領域５４が上下の透孔５０，４０を通じて受圧室７４と平衡室７６に連通されている。これにより、上下の透孔５０，４０と収容領域５４によって、受圧室７４と平衡室７６を相互に連通する連通流路としての第二のオリフィス通路８０が形成されている。第二のオリフィス通路８０は、第一のオリフィス通路７８と同様に、通路断面積の通路長さに対する比などによって、チューニング周波数が設定されている。第二のオリフィス通路８０の具体的なチューニング周波数は、第一のオリフィス通路７８と同様に特に限定されないが、例えば、アイドリング振動に相当する十数Ｈｚ程度、或いは走行こもり音に相当する数十Ｈｚ程度の中乃至高周波に設定される。なお、第二のオリフィス通路８０のチューニング周波数は、第一のオリフィス通路７８よりも高周波に設定されている。それ故、第一のオリフィス通路７８が***振によって実質的に遮断された状態において、第二のオリフィス通路８０を通じた流体流動が生じ得る。 The upper through hole 50 of the partition member 32 is open to the pressure receiving chamber 74, the lower through hole 40 is opened to the equilibrium chamber 76, and the accommodating area 54 is in equilibrium with the pressure receiving chamber 74 through the upper and lower through holes 50 and 40. It is connected to room 76. As a result, the upper and lower through holes 50 and 40 and the accommodating area 54 form a second orifice passage 80 as a communication flow path that communicates the pressure receiving chamber 74 and the equilibrium chamber 76 with each other. Similar to the first orifice passage 78, the tuning frequency of the second orifice passage 80 is set by the ratio of the passage cross-sectional area to the passage length or the like. The specific tuning frequency of the second orifice passage 80 is not particularly limited as in the first orifice passage 78, but is, for example, about a dozen Hz corresponding to idling vibration or several tens Hz corresponding to a running muffled sound. It is set to medium to high frequency. The tuning frequency of the second orifice passage 80 is set to be higher than that of the first orifice passage 78. Therefore, fluid flow through the second orifice passage 80 can occur while the first orifice passage 78 is substantially blocked by antiresonance.

第二のオリフィス通路８０の流路上には、流路長さ方向である軸方向に対して交差方向に広がる可動膜５６が配されている。可動膜５６は、収容領域５４の受圧室７４と平衡室７６への連通方向である第二のオリフィス通路８０の流路長さ方向において、厚さ方向の弾性変形が許容されている。従って、第二のオリフィス通路８０は可動膜５６によって遮断されているが、第二のオリフィス通路８０の防振対象振動の入力時には、可動膜５６の変形による液圧の伝達作用によって、第二のオリフィス通路８０が実質的な連通状態となる。 On the flow path of the second orifice passage 80, a movable membrane 56 extending in an intersecting direction with respect to the axial direction which is the flow path length direction is arranged. The movable membrane 56 is allowed to be elastically deformed in the thickness direction in the flow path length direction of the second orifice passage 80, which is the communication direction between the pressure receiving chamber 74 and the equilibrium chamber 76 in the accommodating region 54. Therefore, the second orifice passage 80 is blocked by the movable membrane 56, but when the vibration-proof target vibration of the second orifice passage 80 is input, the second orifice passage 80 is subjected to the hydraulic pressure transmission action due to the deformation of the movable membrane 56. The orifice passage 80 is in a substantially communicative state.

このような構造とされたエンジンマウント１０は、例えば、第一の取付部材１２がインナブラケットを介してパワーユニットに取り付けられると共に、第二の取付部材１４がアウタブラケットを介して車両ボデーに取り付けられる。これにより、パワーユニットが車両ボデーに対してエンジンマウント１０を介して防振支持される。そして、エンジンマウント１０の車両への装着状態において、軸方向の振動が第一の取付部材１２と第二の取付部材１４の間へ入力される。 In the engine mount 10 having such a structure, for example, the first mounting member 12 is mounted on the power unit via the inner bracket, and the second mounting member 14 is mounted on the vehicle body via the outer bracket. As a result, the power unit is vibration-proof supported with respect to the vehicle body via the engine mount 10. Then, when the engine mount 10 is mounted on the vehicle, axial vibration is input between the first mounting member 12 and the second mounting member 14.

入力振動が第一のオリフィス通路７８のチューニング周波数に相当する低周波大振幅振動の場合には、受圧室７４と平衡室７６の間において、第一のオリフィス通路７８を通じた流体流動が共振状態で積極的に生じる。その結果、流体の流動作用に基づいた防振効果が発揮されて、振動の減衰作用を有効に得ることができる。 When the input vibration is a low-frequency large-amplitude vibration corresponding to the tuning frequency of the first orifice passage 78, the fluid flow through the first orifice passage 78 resonates between the pressure receiving chamber 74 and the equilibrium chamber 76. It occurs positively. As a result, the anti-vibration effect based on the flow action of the fluid is exhibited, and the damping action of the vibration can be effectively obtained.

低周波大振幅振動の入力に対して、第二のオリフィス通路８０の流路上に配された可動膜５６の変形は追従しきれず、可動膜５６の変形による液圧の伝達作用は有効に発揮されない。それ故、第二のオリフィス通路８０が遮断状態とされて、第二のオリフィス通路８０を通じた実質的な流体流動が阻止される。その結果、受圧室７４の内圧変動が効率的に生じて、第一のオリフィス通路７８を通じた流体流動による防振効果が有利に発揮される。なお、第一のオリフィス通路７８の防振対象の振動入力時には、可動膜５６は、圧縮コイルスプリング７０によって収容領域５４の下壁部に押し当てられた状態に保持されることが望ましい。 The deformation of the movable membrane 56 arranged on the flow path of the second orifice passage 80 cannot follow the input of the low-frequency large-amplitude vibration, and the hydraulic pressure transmission action due to the deformation of the movable membrane 56 is not effectively exhibited. .. Therefore, the second orifice passage 80 is shut off to prevent substantial fluid flow through the second orifice passage 80. As a result, the internal pressure fluctuation of the pressure receiving chamber 74 is efficiently generated, and the vibration isolating effect due to the fluid flow through the first orifice passage 78 is advantageously exhibited. At the time of vibration input of the vibration isolation target of the first orifice passage 78, it is desirable that the movable film 56 is held in a state of being pressed against the lower wall portion of the accommodating region 54 by the compression coil spring 70.

入力振動が第二のオリフィス通路８０のチューニング周波数に相当する中乃至高周波の小振幅振動である場合には、入力振動の周波数よりも低周波にチューニングされた第一のオリフィス通路７８は、***振による実質的な遮断状態とされる。 When the input vibration is a medium to high frequency small amplitude vibration corresponding to the tuning frequency of the second orifice passage 80, the first orifice passage 78 tuned to a frequency lower than the frequency of the input vibration is antiresonant. It is considered to be in a substantially blocked state due to.

第二のオリフィス通路８０の流路上に配された可動膜５６が共振状態で変形することから、可動膜５６による液圧の伝達作用が有効に発揮されて、第二のオリフィス通路８０を通じた実質的な流体流動が、受圧室７４と平衡室７６の間で積極的に生じる。その結果、第一のオリフィス通路７８の実質的な遮断による受圧室７４の密閉化が、第二のオリフィス通路８０を通じた実質的な流体流動によって回避されて、エンジンマウント１０の低動ばね化による防振効果（振動絶縁作用）が発揮される。 Since the movable film 56 arranged on the flow path of the second orifice passage 80 is deformed in a resonance state, the hydraulic pressure transmission action of the movable film 56 is effectively exerted, and the substance is substantially passed through the second orifice passage 80. Fluid flow is positively generated between the pressure receiving chamber 74 and the equilibrium chamber 76. As a result, the sealing of the pressure receiving chamber 74 by substantially shutting off the first orifice passage 78 is avoided by the substantial fluid flow through the second orifice passage 80, resulting in a lower dynamic spring of the engine mount 10. Anti-vibration effect (vibration insulation action) is exhibited.

大荷重の入力によって受圧室７４の内圧が平衡室７６の内圧に比して大幅に低下すると、可動膜５６の上面に作用する液圧と、可動膜５６の下面に作用する液圧との差によって、可動膜５６に対して上向きの力が作用する。そして、可動膜５６は、図６に示すように、圧縮コイルスプリング７０を圧縮変形させながら、圧縮コイルスプリング７０の弾性力に抗して上方へ移動する。可動膜５６が収容領域５４の下壁部から離れて上側へ移動することにより、下透孔４０の可動膜５６による覆蓋が解除されて、下透孔４０が開放される。これにより、第二のオリフィス通路８０を通じた流体流動が、可動膜５６によって制限されることなく許容されて、第二のオリフィス通路８０を通じた平衡室７６から受圧室７４への流体の流入によって受圧室７４の圧力低下が可及的速やかに解消される。その結果、受圧室７４の急激な圧力低下によるキャビテーションの発生が防止されて、キャビテーションに起因する異音を回避することができる。 When the internal pressure of the pressure receiving chamber 74 drops significantly compared to the internal pressure of the equilibrium chamber 76 due to the input of a large load, the difference between the hydraulic pressure acting on the upper surface of the movable membrane 56 and the hydraulic pressure acting on the lower surface of the movable membrane 56. As a result, an upward force acts on the movable membrane 56. Then, as shown in FIG. 6, the movable film 56 moves upward against the elastic force of the compression coil spring 70 while compressing and deforming the compression coil spring 70. When the movable film 56 moves upward away from the lower wall portion of the accommodating area 54, the cover of the lower through hole 40 by the movable film 56 is released, and the lower through hole 40 is opened. Thereby, the fluid flow through the second orifice passage 80 is allowed without being restricted by the movable membrane 56, and the pressure is received by the inflow of the fluid from the equilibrium chamber 76 to the pressure receiving chamber 74 through the second orifice passage 80. The pressure drop in the chamber 74 is eliminated as soon as possible. As a result, the occurrence of cavitation due to a sudden drop in pressure in the pressure receiving chamber 74 can be prevented, and abnormal noise caused by cavitation can be avoided.

このように、エンジンマウント１０は、第一のオリフィス通路７８の防振効果と第二のオリフィス通路８０の防振効果とをそれぞれ有効に発揮させる可動膜５６を利用して、受圧室７４の急激な圧力低下を防止するリリーフ機構が構成されている。それ故、通常の振動入力に対する優れた防振性能と、キャビテーションに起因する異音の防止とを、コンパクトな構造によって何れも実現することができる。しかも、コンパクトな構造であっても、可動膜５６の受圧面積を大きく確保できることから、第二のオリフィス通路８０のチューニングを大きな自由度で調節することができる。更に、下透孔４０の開放時における第二のオリフィス通路８０の流量を大きく設定することもできて、キャビテーション異音を効果的に防止することができる。 As described above, the engine mount 10 suddenly uses the movable film 56 that effectively exerts the anti-vibration effect of the first orifice passage 78 and the anti-vibration effect of the second orifice passage 80, respectively. A relief mechanism is configured to prevent a significant pressure drop. Therefore, both excellent vibration isolation performance against normal vibration input and prevention of abnormal noise due to cavitation can be realized by a compact structure. Moreover, even with a compact structure, the pressure receiving area of the movable membrane 56 can be secured to be large, so that the tuning of the second orifice passage 80 can be adjusted with a large degree of freedom. Further, the flow rate of the second orifice passage 80 when the lower through hole 40 is opened can be set to be large, and cavitation abnormal noise can be effectively prevented.

収容領域５４の周壁内面に突出する位置決め突起４２は、可動膜５６が上端位置まで移動した状態において、可動膜５６の外周面と軸直角方向で対向する位置まで軸方向に延びている。これにより、可動膜５６は、圧縮コイルスプリング７０の伸縮変形を伴って軸方向に移動する際に、位置決め突起４２によって位置決めされながら安定して移動する。なお、可動膜５６の上端位置は、例えば、圧縮コイルスプリング７０の最小長さ寸法（最大圧縮変形時の長さ寸法）や可動膜５６の突出部５８と蓋部材３６の嵌合突部５２との当接などによって設定される。 The positioning projection 42 protruding from the inner surface of the peripheral wall of the accommodating region 54 extends axially to a position perpendicular to the outer peripheral surface of the movable film 56 in a state where the movable film 56 has moved to the upper end position. As a result, when the movable film 56 moves in the axial direction with the expansion and contraction deformation of the compression coil spring 70, the movable film 56 moves stably while being positioned by the positioning projection 42. The upper end position of the movable film 56 is, for example, the minimum length dimension of the compression coil spring 70 (the length dimension at the time of maximum compression deformation), the protruding portion 58 of the movable film 56, and the fitting protrusion 52 of the lid member 36. It is set by the contact of.

大荷重の入力によって受圧室７４の内圧が平衡室７６の内圧に比して大幅に上昇すると、可動膜５６の上面に作用する受圧室７４の液圧と、可動膜５６の下面に作用する平衡室７６の液圧との差によって、可動膜５６が平衡室７６である下側へ弾性変形しようとする。その際に、可動膜５６が仕切部材３２の変形制限部７２に当接することにより、可動膜５６の変形量が制限されて、可動膜５６の過大な変形による損傷などが回避される。仕切部材３２の変形制限部７２は、振動が入力されない初期状態において、可動膜５６の下面から離れていることから、小振幅振動の入力時には可動膜５６の変形を阻害しない。 When the internal pressure of the pressure receiving chamber 74 rises significantly compared to the internal pressure of the equilibrium chamber 76 due to the input of a large load, the hydraulic pressure of the pressure receiving chamber 74 acting on the upper surface of the movable membrane 56 and the equilibrium acting on the lower surface of the movable membrane 56. Due to the difference from the hydraulic pressure of the chamber 76, the movable membrane 56 tends to elastically deform downward, which is the equilibrium chamber 76. At that time, the movable film 56 comes into contact with the deformation limiting portion 72 of the partition member 32, so that the amount of deformation of the movable film 56 is limited, and damage due to excessive deformation of the movable film 56 is avoided. Since the deformation limiting portion 72 of the partition member 32 is separated from the lower surface of the movable film 56 in the initial state where vibration is not input, the deformation of the movable film 56 is not hindered when small amplitude vibration is input.

以上、本発明の実施形態について詳述してきたが、本発明はその具体的な記載によって限定されない。例えば、可動膜５６の突出部５８及び拘束部材６２は、圧縮コイルスプリング７０の内周へ差し入れられていても良い。また、可動膜５６は、圧縮コイルスプリング７０の内周へ差し入れられる部分と外周へ差し入れられる部分との両方を備えていても良い。可動膜５６の突出部５８及び拘束部材６２は、必須ではなく、適宜に省略され得る。 Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the specific description thereof. For example, the protruding portion 58 and the restraining member 62 of the movable film 56 may be inserted into the inner circumference of the compression coil spring 70. Further, the movable film 56 may include both a portion inserted into the inner circumference and a portion inserted into the outer circumference of the compression coil spring 70. The protrusion 58 and the restraint member 62 of the movable film 56 are not essential and may be omitted as appropriate.

変形制限部７２は、例えば、下透孔４０の開口を複数に分割するように下透孔４０の内周を軸直角方向に延びる桟状などであっても良い。これによれば、変形制限部７２がより中央に近い位置で可動膜５６に当接することから、特に変形量が大きくなり易い可動膜５６の中央部分の弾性変形が規制されて、耐久性の向上がより有利に図られる。変形制限部７２は、例えば可動膜５６の耐久性が十分に確保される場合などには、必ずしも設けられなくても良い。 The deformation limiting portion 72 may have, for example, a cross-shaped shape extending the inner circumference of the lower through hole 40 in a direction perpendicular to the axis so as to divide the opening of the lower through hole 40 into a plurality of portions. According to this, since the deformation limiting portion 72 comes into contact with the movable film 56 at a position closer to the center, elastic deformation of the central portion of the movable film 56, in which the amount of deformation tends to be particularly large, is restricted, and durability is improved. Is more advantageous. The deformation limiting portion 72 may not necessarily be provided, for example, when the durability of the movable film 56 is sufficiently ensured.

前記実施形態では、入力のない初期状態において、第二のオリフィス通路８０が可動膜５６によって流体密に閉塞されているが、収容領域５４と平衡室７６を常時連通状態とする短絡通路を設けても良い。具体的には、例えば、可動膜５６の下面と収容領域５４の下壁部の上面との間に径方向に延びる短絡通路を設けて、短絡通路によって収容領域５４と平衡室７６を常時連通状態とすることができる。これによれば、例えば、可動膜５６の共振周波数とは異なる周波数域で短絡通路を通じた流体流動による防振効果を得ることもできて、防振特性のブロード化などが実現される。 In the above embodiment, in the initial state where there is no input, the second orifice passage 80 is fluidly closed by the movable membrane 56, but a short-circuit passage is provided so that the accommodating region 54 and the equilibrium chamber 76 are always in communication with each other. Is also good. Specifically, for example, a short-circuit passage extending in the radial direction is provided between the lower surface of the movable membrane 56 and the upper surface of the lower wall portion of the accommodation region 54, and the accommodation region 54 and the equilibrium chamber 76 are always in communication with each other by the short-circuit passage. Can be. According to this, for example, it is possible to obtain an anti-vibration effect due to the fluid flow through the short-circuit passage in a frequency range different from the resonance frequency of the movable membrane 56, and it is possible to broaden the anti-vibration characteristics.

前記実施形態では、特定周波数の振動入力に対して防振効果を発揮する第二のオリフィス通路８０が、収容領域５４を含む連通流路の全体によって構成されていたが、連通流路の全体がオリフィス通路を構成する必要はない。例えば、収容領域がオリフィス通路の延長上に直列的に設けられて、それら収容領域とオリフィス通路によって連通流路を構成することもできる。この場合には、連通流路の一部が流体の流動作用に基づく防振効果を発揮するオリフィス通路とされると共に、連通流路の他の一部である収容領域は、流体の流動作用に基づく防振効果を発揮しなくても良い。また、連通流路は、必ずしも収容領域の全体を含む必要はなく、例えば収容領域の一部を含んでいても良い。 In the above embodiment, the second orifice passage 80 that exerts a vibration isolating effect against the vibration input of a specific frequency is composed of the entire communication flow path including the accommodation area 54, but the entire communication flow path is formed. It is not necessary to construct an orifice passage. For example, accommodating areas may be provided in series on an extension of the orifice passage, and the accommodating area and the orifice passage may form a communication flow path. In this case, a part of the communication flow path is an orifice passage that exerts a vibration isolation effect based on the fluid flow action, and the accommodating area that is another part of the communication flow path has a fluid flow action. It is not necessary to exert the anti-vibration effect based on this. Further, the communication flow path does not necessarily include the entire accommodating area, and may include, for example, a part of the accommodating area.

１０ エンジンマウント（流体封入式防振装置）
１２ 第一の取付部材
１４ 第二の取付部材
１６ 本体ゴム弾性体
１８ フランジ状部
２０ ねじ穴
２２ 凹所
２４ シールゴム層
２６ 可撓性膜
２８ 固定部材
３０ 流体室
３２ 仕切部材
３４ 仕切部材本体
３６ 蓋部材
３８ 収容凹所
４０ 下透孔
４２ 位置決め突起
４４ 周溝
４６ 第一の連通口
４８ 第二の連通口
５０ 上透孔
５２ 嵌合突部
５４ 収容領域
５６ 可動膜
５８ 突出部
５９ 凹状面
６０ リップ
６２ 拘束部材
６４ 受け部
６６ 位置決め部
６８ 変形許容部
６９ 隙間
７０ 圧縮コイルスプリング
７２ 変形制限部
７４ 受圧室
７６ 平衡室
７８ 第一のオリフィス通路
８０ 第二のオリフィス通路（連通流路） 10 Engine mount (fluid-filled anti-vibration device)
12 First mounting member 14 Second mounting member 16 Body rubber elastic body 18 Flange-shaped part 20 Screw hole 22 Recess 24 Seal rubber layer 26 Flexible film 28 Fixing member 30 Fluid chamber 32 Partition member 34 Partition member body 36 Lid Member 38 Storage recess 40 Lower through hole 42 Positioning protrusion 44 Circumferential groove 46 First communication port 48 Second communication port 50 Upper through hole 52 Fitting protrusion 54 Storage area 56 Movable membrane 58 Protruding part 59 Concave surface 60 Lip 62 Restraint member 64 Receiving part 66 Positioning part 68 Deformation allowable part 69 Gap 70 Compression coil spring 72 Deformation limiting part 74 Pressure receiving chamber 76 Balance chamber 78 First orifice passage 80 Second orifice passage (communication flow path)

Claims (4)

仕切部材の両側にそれぞれ非圧縮性流体が封入された受圧室と平衡室が形成されており、それら受圧室と平衡室を相互に連通する連通流路が形成されている流体封入式防振装置において、
前記仕切部材の内部に収容領域が設けられて、前記連通流路が該収容領域を含んで構成されていると共に、該収容領域における該受圧室と該平衡室の連通方向で弾性変形可能とされた可動膜が該収容領域に配されており、該収容領域の該受圧室側の壁部と該可動膜との間に圧縮コイルスプリングが配されて、該可動膜が該圧縮コイルスプリングによって該収容領域の該平衡室側の壁部に押し当てられている流体封入式防振装置。 A fluid-filled anti-vibration device in which a pressure receiving chamber and an equilibrium chamber in which an incompressible fluid is sealed are formed on both sides of the partition member, and a communication flow path for communicating the pressure receiving chamber and the equilibrium chamber with each other is formed. In
An accommodating region is provided inside the partition member, the communication flow path includes the accommodating region, and elastically deformable in the communicating direction between the pressure receiving chamber and the equilibrium chamber in the accommodating region. A movable membrane is arranged in the accommodating area, a compression coil spring is arranged between the wall portion of the accommodating area on the pressure receiving chamber side and the movable membrane, and the movable membrane is formed by the compression coil spring. A fluid-filled anti-vibration device pressed against the wall of the accommodation area on the equilibrium chamber side. 前記可動膜の外周部分に拘束部材が埋設状態で配されており、
該拘束部材が、前記圧縮コイルスプリングの軸方向端面に重ね合わされる受け部と、該圧縮コイルスプリングの内周と外周の少なくとも一方に差し入れられる位置決め部とを、備えている請求項１に記載の流体封入式防振装置。 A restraint member is embedded in the outer peripheral portion of the movable film.
The first aspect of the present invention, wherein the restraining member includes a receiving portion that is superposed on the axial end surface of the compression coil spring, and a positioning portion that is inserted into at least one of the inner circumference and the outer circumference of the compression coil spring. Fluid-filled anti-vibration device. 前記可動膜において厚さ方向の弾性変形を許容される変形許容部が設けられており、該変形許容部の厚さ寸法に対して、該変形許容部の厚さと直交する方向の外寸が６倍以上とされている請求項１又は２に記載の流体封入式防振装置。 The movable film is provided with a deformation permissible portion that allows elastic deformation in the thickness direction, and the outer dimension in the direction orthogonal to the thickness of the deformation permissible portion is 6 with respect to the thickness dimension of the deformation permissible portion. The fluid-filled anti-vibration device according to claim 1 or 2, which is more than doubled. 前記可動膜の変形量を制限する変形制限部が、該可動膜に対して前記平衡室側に離れて設けられている請求項１〜３の何れか一項に記載の流体封入式防振装置。 The fluid-filled anti-vibration device according to any one of claims 1 to 3, wherein a deformation limiting portion that limits the amount of deformation of the movable film is provided on the equilibrium chamber side of the movable film. ..

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