Fluid-filled vibration isolation device

Abstract

This invention provides a novel fluid-sealed vibration damping device capable of effectively suppressing cavitation. The outer peripheral end of the movable membrane 68 includes: an abutment portion 70, which partially abuts against the inner wall surface 55 of the pressure chamber 84 side of the receiving space 66 in the circumferential direction; and a sealing portion 72, which abuts against the inner wall surface 65 of the balance chamber 86 side of the receiving space 66 in the entire circumferential range. The outer peripheral end of the movable membrane 68 is supported by a partition member 40. A gap 80 is provided between the opposing outer peripheral surface of the movable membrane 68 and the inner peripheral surface of the receiving space 66. Furthermore, at the outer peripheral end of the movable membrane 68, a connecting passage 82 communicating with the gap 80 is provided at a position away from the inner wall surface 55 of the receiving space 66. The outer peripheral end of the movable membrane 68 leaves the inner wall surface 65 of the receiving space 66 due to the pressure difference between the pressure chamber 84 and the balance chamber 86. Thus, the overflow passage 94 connecting the pressure chamber 84 and the balance chamber 86 is configured to include the gap 80 and the connecting passage 82.

Description

Technical Field

[0001] This invention relates to a fluid-sealed vibration damping device for use on engine mounts and the like in motor vehicles. Background Technology

[0002] Previously, vibration damping devices were known for use in vibration damping supports for motor vehicle power units, etc. Furthermore, with the aim of improving vibration damping performance, Japanese Patent Application Publication No. 2013-231480 (Patent Document 1) proposed a fluid-sealed vibration damping device. This fluid-sealed vibration damping device has a structure that divides a main fluid chamber and a secondary fluid chamber, which are sealed with fluid, by a partition member. In addition, Patent Document 1 provides an elastic membrane on the partition member, which, upon vibration input, provides a vibration damping effect through hydraulic absorption based on the deformation of the elastic membrane.

[0003] However, in fluid-sealed vibration damping devices, the generation of abnormal noises caused by cavitation can sometimes become a problem. Cavitation is caused by a sharp drop in the internal pressure of the main liquid chamber. Therefore, in Patent Document 1, an overflow valve for suppressing cavitation is located in the center of the elastic diaphragm. By opening the overflow valve when the internal pressure of the main liquid chamber drops significantly, fluid flowing from the auxiliary liquid chamber to the main liquid chamber flows in, easing the negative pressure in the main liquid chamber and suppressing cavitation.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-231480 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in the construction of Patent Document 1, where the overflow valve is located in the center of the elastic membrane, it is difficult to extend the circumference of the overflow valve and increase the cross-sectional area of ​​the overflow path that switches between connection and blockage through the overflow valve. As a result, Patent Document 1 identifies a new problem: even when the overflow valve is open, a sufficient amount of fluid cannot flow from the auxiliary liquid chamber to the main liquid chamber, thus sometimes failing to adequately alleviate the negative pressure in the main liquid chamber.

[0009] The problem solved by the present invention is to provide a fluid-sealed vibration damping device with a novel structure that can effectively suppress cavitation.

[0010] means for solving problems

[0011] The following describes preferred embodiments for understanding the present invention, but these embodiments are exemplary and can be appropriately combined with each other. Furthermore, the various constituent elements described in each embodiment can be identified and employed as independently as possible, and can also be appropriately combined with any constituent elements described in other embodiments. Therefore, the present invention is not limited to the embodiments described below, and various other embodiments can be implemented.

[0012] The first embodiment is a fluid-sealed vibration damping device, wherein a pressure chamber and a balance chamber are separated by a partition member. A movable membrane is housed within a receiving space formed in the partition member. The outer peripheral end of the movable membrane has: an abutment portion that partially abuts against the inner wall surface of the receiving space on the pressure chamber side in the circumferential direction; and a sealing portion that abuts against the inner wall surface of the receiving space on the balance chamber side in the entire circumference. The outer peripheral end of the movable membrane is supported by the partition member. A gap is provided between the opposing outer peripheral surface of the movable membrane and the inner peripheral surface of the receiving space. Furthermore, a communication path communicating with the gap is provided at the outer peripheral end of the movable membrane at a position offset from the abutment portion towards the inner wall surface of the receiving space on the pressure chamber side. The outer peripheral end of the movable membrane leaves the inner wall surface of the receiving space on the balance chamber side due to the pressure difference between the pressure chamber and the balance chamber. Thus, the overflow path communicating between the pressure chamber and the balance chamber is configured to include the gap and the communication path.

[0013] The fluid-sealed vibration damping device, constructed according to this method, opens when the internal pressure of the pressure chamber decreases, forming an overflow path that connects the pressure chamber and the balance chamber. As a result, the decrease in internal pressure of the pressure chamber is rapidly reduced by the inflow of fluid from the balance chamber through the overflow path into the pressure chamber, preventing cavitation caused by a large decrease in internal pressure of the pressure chamber and preventing abnormal noises associated with cavitation.

[0014] The overflow path comprises: a connecting passage extending between the outer peripheral end of the movable membrane and the inner wall surface of the pressure chamber side of the receiving space; and a gap formed between the outer peripheral surface of the movable membrane and the inner peripheral surface of the receiving space, with the overflow path located in the outer peripheral portion of the receiving space. Therefore, the overflow path does not require a large-scale fluid-sealed vibration damping device, allowing for a longer circumferential length and ensuring a larger cross-sectional area. Consequently, by rapidly eliminating the pressure drop in the pressure chamber through the fluid flow via the overflow path, cavitation can be effectively prevented.

[0015] Under normal vibration input conditions where cavitation is not a problem, the sealing part of the movable diaphragm abuts against the inner surface of the wall of the balancing chamber side of the containment space, thereby closing the overflow path and preventing short circuits between the pressure chamber and the balancing chamber through the overflow path. Therefore, under normal vibration input, it efficiently induces pressure changes in the pressure chamber, effectively utilizing the vibration damping effect brought about by fluid flow and the hydraulic absorption effect of the movable diaphragm.

[0016] The second method is based on the fluid-sealed vibration damping device described in the first method. At the outer peripheral end of the movable membrane, a plurality of elastic protrusions protruding toward the pressure chamber side are provided in the circumferential direction. The elastic protrusions abut against the inner wall surface of the pressure chamber side of the receiving space in the partition member to form an abutment portion, and the connecting passage is formed between the plurality of elastic protrusions in the circumferential direction.

[0017] According to the fluid-sealed vibration damping device constructed in accordance with this method, the contact portion is formed as an elastic protrusion. Therefore, by means of the elastic protrusion and the deformation rigidity of the movable diaphragm, displacement of the outer peripheral end of the movable diaphragm towards the pressure chamber side due to compression of the elastic protrusion is allowed. For example, the sealing portion separates from the inner wall surface of the balancing chamber side of the accommodating space over approximately the entire circumferential range, thereby forming an overflow path. Since multiple elastic protrusions are provided circumferentially on the movable diaphragm, the spring constant of the elastic protrusions can be adjusted by means of the circumferential width dimension and spacing of the elastic protrusions, thereby setting a threshold for the reduction of internal pressure in the pressure chamber where the overflow path is opened.

[0018] The third method, based on the fluid-sealed vibration damping device described in the second method, utilizes the pressure difference between the pressure chamber and the balance chamber to act on the movable membrane. The sealing portion at the outer peripheral end of the movable membrane separates from the inner wall surface of the balance chamber side of the receiving space in the circumferential direction of the elastic protrusion. Under the premise that the contact state between the inner wall surface of the pressure chamber side and the elastic protrusion, and between the inner wall surface of the balance chamber side and the sealing portion remains unchanged at the formation location of the elastic protrusion, the overflow path appears.

[0019] According to the fluid-sealed vibration damping device constructed in accordance with this method, for example, through the elastic protrusion and the deformable rigidity of the movable diaphragm, when the internal pressure of the pressure chamber decreases, the elastic protrusion at the outer peripheral end of the movable diaphragm maintains contact with the inner surfaces of the walls of the pressure chamber side and the balance chamber side of the accommodating space by means of the elastic protrusion and the sealing part. On the other hand, the sealing part separates from the inner surface of the wall of the balance chamber side in the circumferential direction between the elastic protrusions at the outer peripheral end of the movable diaphragm, thereby forming an overflow path. That is, according to the elastic protrusion and the deformable rigidity of the movable diaphragm, the sealing part can separate from the inner surface of the wall of the balance chamber side in a substantially circumferential range to form an overflow path as in the first embodiment described later, and the sealing part can also separate from the inner surface of the wall of the balance chamber side in the circumferential direction between the elastic protrusions to form an overflow path as in this method and the third embodiment described later. In summary, for example, in the fluid-sealed vibration damping device involved in the second method, the overflow path can be constructed in an appropriate manner according to the elastic protrusion, the deformability and rigidity of the movable membrane, etc., thereby improving the design freedom of the elastic protrusion, the movable membrane, and thus the fluid-sealed vibration damping device.

[0020] The fourth method is based on the fluid-sealed vibration damping device described in the second or third method, wherein the elastic protrusion is formed into a pointed shape that tapers toward the protruding front end.

[0021] According to the fluid-sealed vibration damping device constructed in accordance with this method, the change in the elastic constant caused by the compression of the elastic protrusion is nonlinear. Therefore, even when the internal pressure of the pressure chamber drops significantly, it can prevent the connection path from being blocked by completely flattening the elastic protrusion, and can prevent unintentional blockage of the overflow path.

[0022] The fifth method is based on the fluid-sealed vibration damping device described in any one of the second to fourth methods, wherein the protruding front end face of the elastic protrusion is formed into a spherical crown-shaped curved surface.

[0023] According to the fluid-sealed vibration damping device constructed in accordance with this method, when the contact portion is abutted against the inner surface of the pressure chamber side of the containing space, stress concentration on the surface of the contact portion is avoided, thereby improving the durability of the contact portion. Furthermore, for example, when a large positive pressure acts on the pressure chamber, after the contact portion of the movable diaphragm leaves the inner surface of the pressure chamber side of the containing space, and the contact portion abuts against the inner surface of the pressure chamber side of the containing space again due to the release of this positive pressure, noise is reduced.

[0024] The sixth embodiment is based on the fluid-sealed vibration damping device described in any one of the first to fifth embodiments, wherein the separating member has a plurality of grooves that open on the outer peripheral portion of the inner wall surface of the pressure chamber side in the receiving space, the outer peripheral end of the movable membrane and the inner wall surface of the pressure chamber side of the receiving space abut against each other at a portion offset circumferentially from the groove, and the communication route is formed by the groove.

[0025] According to the fluid-sealed vibration damping device constructed in accordance with this method, by forming a groove on the inner surface of the wall on the pressure chamber side of the receiving space, a communication path based on the groove can be formed at a position away from the contact portion without providing a protrusion or the like at the outer peripheral end of the movable diaphragm. When the internal pressure of the pressure chamber decreases, the contact portion of the movable diaphragm is pressed against the inner surface of the wall on the pressure chamber side of the receiving recess at a position away from the groove and is compressed, thereby allowing the outer peripheral end of the movable diaphragm to displace towards the pressure chamber side. Therefore, the sealing portion separates from the inner surface of the wall on the balance chamber side of the receiving space, forming an overflow path.

[0026] The seventh embodiment, based on the fluid-sealed vibration damping device described in any one of the first to sixth embodiments, includes a sealing portion having a sealing lip that protrudes toward the balance chamber side and is continuous throughout its circumference, the sealing lip abutting against the inner surface of the balance chamber side wall of the receiving space throughout its circumference. Alternatively, in this embodiment, the outer peripheral end of the movable membrane may have a sealing lip that protrudes toward the balance chamber side and is continuous throughout its circumference, the sealing lip abutting against the inner surface of the balance chamber side wall of the receiving space throughout its circumference.

[0027] According to the fluid-sealed vibration damping device constructed in accordance with this method, by providing a sealing lip to the sealing part, the sealing performance is improved by the sealing part abutting against the inner surface of the wall of the equilibration chamber side of the accommodating space, thereby improving the vibration damping performance against input of normal vibration.

[0028] Invention Effects

[0029] According to the present invention, cavitation can be effectively suppressed. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view showing the engine bracket as a first embodiment of the present invention, and is related to... Figure 3 The diagram corresponds to section II in the figure.

[0031] Figure 2 It constitutes Figure 1 A perspective view of the partition components of the engine mount shown.

[0032] Figure 3 yes Figure 2 The top view of the dividing member shown.

[0033] Figure 4 It constitutes Figure 1 A three-dimensional view of the movable membrane of the engine mount shown.

[0034] Figure 5 It is expressed from other perspectives Figure 4 A three-dimensional view of a movable membrane.

[0035] Figure 6 yes Figure 4 The cross-sectional view of the movable membrane shown.

[0036] Figure 7 yes Figure 1 The cross-sectional view of the engine bracket shown is a diagram illustrating the connection state of the overflow path.

[0037] Figure 8 This is a cross-sectional view showing the engine bracket as a second embodiment of the present invention.

[0038] Figure 9 The connection state of the overflow path is represented by the partition member in the engine bracket of the third embodiment of the present invention, which is related to... Figure 7 Corresponding to (the first embodiment) Figure 3 A cross-sectional view (equivalent to section II).

[0039] Figure 10 In order to explain Figure 9 The diagram shows a cross-sectional view of the movable membrane, which is arranged inside the partition member, in a deformable manner, with the partition member removed. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0041] exist Figure 1 The image shows an engine mount 10 for a motor vehicle as a first embodiment of a fluid-sealed vibration damping device constructed according to the present invention. The engine mount 10 has a structure in which a first mounting member 12 and a second mounting member 14 are elastically connected by a main body rubber elastomer 16. In the following description, as a general rule, the vertical direction refers to the direction along the axis of the mount. Figure 1 The up and down directions in the middle.

[0042] The first mounting member 12 integrally comprises: a rectangular cylindrical bracket assembly 18 extending in a direction perpendicular to the axis; and a cylindrical fixing portion 20 extending downward around a circular hole that passes through the lower wall of the bracket assembly 18. The first mounting member 12 can be obtained, for example, by stamping a sheet metal.

[0043] The second mounting member 14 is formed in a generally cylindrical shape with steps, with a large-diameter cylindrical portion 22 at the top and a small-diameter cylindrical portion 24 at the bottom that is smaller than the inner diameter of the large-diameter cylindrical portion 22. The second mounting member 14 is disposed below on a central axis that is approximately the same as that of the first mounting member 12, and a main rubber elastomer 16 is disposed between the first mounting member 12 and the second mounting member 14.

[0044] The main body rubber elastomer 16 is formed in a generally frustum-shaped manner. Its upper portion, on the smaller diameter side, is vulcanized and bonded to the fixing portion 20 of the first mounting member 12, and its outer peripheral surface, on the larger diameter side, is vulcanized and bonded to the larger diameter cylindrical portion 22 of the second mounting member 14. The main body rubber elastomer 16 has a recess 26 with an opening on its lower surface and a smaller diameter formed upwards. The recess 26 is located below the fixing portion 20 of the first mounting member 12 and within the inner periphery of the smaller diameter cylindrical portion 24 of the second mounting member 14.

[0045] The bracket assembly portion 18 of the first mounting member 12 has a stop rubber 28 integrally formed with the main rubber elastomer 16 fixed to its outer peripheral surface, and an insert rubber 30 integrally formed with the main rubber elastomer 16 fixed to its inner peripheral surface. The inner peripheral surface of the small-diameter cylindrical portion 24 of the second mounting member 14 is integrally formed with the main rubber elastomer 16 and is covered by a sealing rubber layer 32 extending downward from around the recess 26.

[0046] A flexible membrane 34 is installed in the small-diameter cylindrical portion 24 of the second mounting member 14. The flexible membrane 34 is a thin-walled rubber membrane with flexibility and vertical looseness. An annular fixing member 36 is fixed to the outer peripheral end of the flexible membrane 34, and the fixing member 36 is fixed to the lower end of the small-diameter cylindrical portion 24 of the second mounting member 14. Moreover, by fixing the fixing member 36 to the second mounting member 14, the flexible membrane 34 is configured to seal the opening on the lower side of the second mounting member 14. The fixing method for fixing the fixing member 36 to the second mounting member 14 is not particularly limited. For example, with the fixing member 36 inserted into the inner periphery of the second mounting member 14, the fixing member 36 can be fixed to the second mounting member 14 by applying a diameter reduction process. Furthermore, since the sealing rubber layer 32 is sandwiched between the small-diameter cylindrical portion 24 of the second mounting member 14 and the fixing member 36, the second mounting member 14 and the fixing member 36 are fluid-tightly sealed.

[0047] A flexible membrane 34 is mounted on a second mounting member 14 fixed to the main rubber elastomer 16, thereby sealing a fluid chamber 38 between the main rubber elastomer 16 and the flexible membrane 34, thus preventing external fluid from entering. The fluid chamber 38 is sealed with an incompressible fluid. While not particularly limited, the incompressible fluid can be, for example, water, ethylene glycol, alkylene glycols, polyalkylene glycols, silicone oil, or mixtures thereof.

[0048] A partition member 40 is disposed in the fluid chamber 38. For example... Figure 2 , Figure 3 As shown, the partition member 40 is formed in a generally circular plate shape and has a first partition plate 42 and a second partition plate 44.

[0049] The first partition plate 42 is integrally formed into a circular plate shape and is a rigid component made of metal, synthetic resin, or the like. A circumferential groove 46 is formed at the outer peripheral end of the first partition plate 42, opening on the outer peripheral surface and extending circumferentially. A circular central recess 48, opening on the upper surface, is formed in the central portion of the first partition plate 42, located closer to the inner periphery than the circumferential groove 46. A first central through-hole 50 with a circular cross-section penetrating the center in the vertical direction and a plurality of first peripheral through-holes 52 penetrating in the vertical direction, located closer to the outer periphery than the first central through-hole 50, are formed on the bottom wall of the central recess 48. A circular receiving recess 54, opening on the lower surface, is formed in the central portion of the first partition plate 42. The receiving recess 54 is larger in diameter than the inner diameter of the central recess 48 and has a shallow bottom; the outer peripheral end of the receiving recess 54 is located closer to the outer periphery than the central recess 48. The inner surface of the upper bottom wall of the receiving recess 54, i.e., the first inner wall surface 55, is formed as a first narrow portion 56 protruding downwards from the radially central portion. The first central through hole 50 and the first peripheral through hole 52 penetrate the common portion of the bottom wall of the central recess 48 and the receiving recess 54, thereby connecting the central recess 48 and the receiving recess 54.

[0050] The second partition plate 44, like the first partition plate 42, is a rigid component, formed into a generally circular plate shape with a thinner wall than the first partition plate 42. A second central through-hole 58 with a circular cross-section extending vertically is formed in the central portion of the second partition plate 44. A plurality of second peripheral through-holes 60 extending vertically are formed in the second partition plate 44 at a portion peripherally adjacent to the second central through-hole 58, arranged circumferentially. A second narrow portion 62 protruding upwards is provided between the second peripheral through-holes 60 in the second partition plate 44. A groove-shaped sealing abutment portion 64, opening on its upper surface and extending circumferentially, is provided in the second partition plate 44 at a portion peripherally adjacent to the second narrow portion 62. The sealing abutment portion 64 and the upper surface of the second partition plate 44, formed from the portion peripherally adjacent to the sealing abutment portion 64, are formed as a second inner wall surface 65 in the partition member 40, opposing the inner surface 55 of the first wall in the vertical direction.

[0051] The first partition plate 42 and the second partition plate 44 overlap each other in the vertical direction. By overlapping the lower surface of the second partition plate 44 with the lower surface of the first partition plate 42, the opening of the receiving recess 54 of the first partition plate 42 is covered by the second partition plate 44, forming a receiving space 66 between the first partition plate 42 and the second partition plate 44. The inner wall surface of the upper side of the receiving space 66, which becomes the pressure chamber 84 (described later), is formed by the first inner wall surface 55 of the first partition plate 42, and the inner wall surface of the lower side of the receiving space 66, which becomes the balance chamber 86 (described later), is formed by the second inner wall surface 65 of the second partition plate 44. In the partition member 40, the first central through hole 50 and the first peripheral through hole 52 penetrate the upper wall portion of the receiving space 66 and communicate with the receiving space 66, and the second central through hole 58 and the second peripheral through hole 60 penetrate the lower wall portion of the receiving space 66 and communicate with the receiving space 66. The first central through hole 50 and the second central through hole 58 are arranged in positions corresponding to each other in the vertical direction, and the first peripheral through hole 52 and the second peripheral through hole 60 are arranged in positions corresponding to each other in the vertical direction.

[0052] A movable membrane 68 is disposed in the receiving space 66 of the partition member 40. For example... Figure 4 , Figure 5 As shown, the movable membrane 68 is integrally formed into a circular plate shape. The movable membrane 68 is formed of a rubber elastomer, allowing elastic flexural deformation in the thickness direction. Furthermore, depending on the required vibration damping performance and the deformation rigidity of the elastic protrusion 70 (described later), rigid plates such as metal or resin can be partially or integrally embedded in the movable membrane 68, thereby adjusting the local or overall deformation characteristics.

[0053] An upwardly protruding elastic protrusion 70 is integrally formed at the outer peripheral end of the movable membrane 68. The elastic protrusion 70 protrudes upward from the outer peripheral end of the movable membrane 68 toward the side that becomes the pressure chamber 84, which will be described later. Multiple elastic protrusions 70 are provided, separated from each other in the circumferential direction. The elastic protrusion 70 has a generally circular cross-section. The elastic protrusion 70 is formed into a pointed shape that gradually tapers toward the protruding tip (becoming a small diameter). The protruding tip surface of the elastic protrusion 70 can be a flat surface, a pointed convex surface, etc., but in this embodiment, it is formed into a convex, crown-shaped curved surface toward the protruding tip. Although the number and arrangement of the elastic protrusions 70 are not particularly limited, in this embodiment, sixteen elastic protrusions 70 are arranged at approximately equal intervals in the circumferential direction.

[0054] A sealing portion 72 is provided at the outer peripheral end of the movable membrane 68. The sealing portion 72 is the lower portion of the outer peripheral end of the movable membrane 68, and in this embodiment, it includes an outer peripheral lip 74 and an inner peripheral lip 76 as sealing lips. The outer peripheral lip 74, as shown in the image... Figure 6As shown in the enlarged view, the movable membrane 68 protrudes downward toward the balance chamber 86 (described later) and is formed into a ring that extends continuously in the circumferential direction. The inner lip 76 protrudes downward at a position closer to the inner circumference than the outer lip 74 and is formed into a ring that extends circumferentially alongside the outer lip 74.

[0055] On the inner periphery of the movable membrane 68, a plurality of cushioning protrusions 78 are provided on both the upper and lower surfaces. The cushioning protrusions 78 are formed in a generally hemispherical shape. The height and width dimensions of the protrusions 78 are smaller than those of the elastic protrusions 70. Figures 4-6 As shown, the buffer protrusion 78 in this embodiment is formed as tiny protrusions, and multiple of them are arranged in a roughly cross shape.

[0056] like Figure 1 As shown, the movable membrane 68 is disposed in the receiving space 66 of the partition member 40. Regarding the movable membrane 68, its outer peripheral end, which includes an elastic protrusion 70 and a sealing portion 72, is located at a position further outward than the first outer peripheral through-hole 52 and the second outer peripheral through-hole 60, and is disposed between the opposing first partition plate 42 and the second partition plate 44. Furthermore, regarding the outer peripheral end of the movable membrane 68, the elastic protrusion 70 is pressed against the first inner wall surface 55 of the first partition plate 42, and the sealing portion 72 is pressed against the second inner wall surface 65 of the second partition plate 44 (sealing abutment portion 64), thus being held between the upper and lower parts of the first partition plate 42 and the second partition plate 44. Additionally, the vertical dimension of the inner peripheral portion of the receiving space 66 is formed to be larger than the vertical dimension of the inner peripheral portion of the movable membrane 68, allowing the inner peripheral portion of the movable membrane 68 to displace in the vertical direction accompanied by elastic deformation.

[0057] The outer diameter of the movable membrane 68 is smaller than the inner diameter of the receiving space 66. When the movable membrane 68 is positioned in the receiving space 66, the outer peripheral surface of the movable membrane 68 and the inner surface of the peripheral wall of the receiving space 66 are radially separated from each other. Therefore, an annular gap 80 extending circumferentially is provided between the outer peripheral surface of the movable membrane 68 and the inner surface of the peripheral wall of the receiving space 66 in the radial direction. In this embodiment, the gap 80 is provided throughout the entire circumference. However, if the internal pressure of the pressure chamber 84 decreases as described later, and cavitation is sufficiently prevented by configuring an overflow path including the gap, the gap between the outer peripheral surface of the movable membrane and the inner surface of the peripheral wall of the receiving space in the radial direction can be provided locally in the circumferential direction.

[0058] With the elastic protrusions 70 pressed against the inner surface of the upper wall of the receiving space 66, a gap is maintained between the circumferentially adjacent elastic protrusions 70, 70. Through the gap between the elastic protrusions 70, 70, a connecting path 82 is formed, extending between the movable membrane 68 and the partition member 40 and communicating with the gap 80. In this embodiment, the plurality of connecting paths 82 extend radially, but the connecting paths do not necessarily have to extend radially along the movable membrane 68; the number is not limited as long as there are multiple paths. The outer peripheral end of the movable membrane 68 abuts against the inner wall surface (first inner wall surface 55) of the receiving space 66 on the pressure chamber 84 side (described later) at the portion where the elastic protrusions 70 are formed, and separates from the first inner wall surface 55 at a position circumferentially offset from the elastic protrusions 70. Therefore, the abutting portion abutting against the inner wall surface 55 on the pressure chamber 84 side of the receiving space 66 is constituted by the elastic protrusions 70 and is partially provided in the circumferential direction. In summary, in this embodiment, a connecting passage 82 communicating with the gap 80 is provided at a position in the outer peripheral end of the movable membrane 68 that is offset from the elastic protrusion 70, which serves as the abutment portion, in the circumferential direction.

[0059] The sealing portion 72 is pressed against the sealing contact portion 64 of the second partition plate 44 all around its circumference, forming a sealing structure that prevents communication between the gap 80, the second central through hole 58, and the second peripheral through hole 60. In this embodiment, the sealing portion 72 has an outer peripheral lip 74 and an inner peripheral lip 76, and a double sealing structure is provided by pressing both the outer peripheral lip 74 and the inner peripheral lip 76 against the second partition plate 44. Of course, a sealing structure based on a single sealing lip, a sealing structure based on overlapping three or more sealing lips, etc., can also be used. Alternatively, a sealing lip may be omitted.

[0060] Thus, the outer peripheral end of the movable membrane 68, which has the elastic protrusion 70 and the sealing portion 72, is supported by the partition member 40 clamped in the vertical direction. The inner peripheral portion of the movable membrane 68 is allowed to undergo slight vertical displacement with flexural deformation within the receiving space 66.

[0061] like Figure 1As shown, a partition member 40 housing a movable membrane 68 is disposed in the fluid chamber 38. The partition member 40 disposed in the fluid chamber 38 extends in a direction perpendicular to the axis, and its outer peripheral surface is supported to overlap with the inner peripheral surface of the small-diameter cylindrical portion 24 of the second mounting member 14. The outer peripheral surface of the partition member 40 overlaps with the second mounting member 14 via a sealing rubber layer 32, thus the overlapping surfaces of the partition member 40 and the second mounting member 14 are fluid-tightly sealed. The method of fixing the second mounting member 14 and the partition member 40 is not particularly limited. For example, with the partition member 40 inserted into the inner periphery of the second mounting member 14, the second mounting member 14 is reduced in diameter, and fixed by pressing the inner peripheral surface of the second mounting member 14 and the outer peripheral surface of the partition member 40 via the sealing rubber layer 32. Furthermore, by reducing the diameter of the second mounting member 14, the pre-compression of the main rubber elastomer 16, the installation of the flexible membrane 34 onto the second mounting member 14, and the installation of the partition member 40 onto the second mounting member 14 can be performed in one step.

[0062] The fluid chamber 38 is divided into two parts by the partition member 40, forming a pressure chamber 84 and a balance chamber 86. Specifically, the portion of the fluid chamber 38 above the partition member 40 is formed as a pressure chamber 84, which is part of the wall formed by the main rubber elastomer 16. The portion of the fluid chamber 38 below the partition member 40 is formed as a balance chamber 86, which is part of the wall formed by a flexible membrane 34. Both the pressure chamber 84 and the balance chamber 86 are filled with an incompressible fluid. The pressure chamber 84 experiences internal pressure fluctuations upon vibration input, while the balance chamber 86 allows for volume changes. Furthermore, for example, by performing the installation of the flexible membrane 34 and the partition member 40 onto the second mounting member 14 within the incompressible fluid, it is possible to fill both the pressure chamber 84 and the balance chamber 86 with an incompressible fluid.

[0063] By mounting the partition member 40 onto the second mounting member 14, the opening of the circumferential groove 46 is fluid-tightly sealed by the second mounting member 14 covered by the sealing rubber layer 32, thereby forming a circumferentially extending flow path. One end of this flow path communicates with the pressure chamber 84 through a first connecting port 88 formed in the first partition plate 42, and the other end communicates with the balance chamber 86 through a second connecting port 90 formed in the second partition plate 44. Thus, a throttling flow path 92 connecting the pressure chamber 84 and the balance chamber 86 is formed using the circumferential groove 46. The throttling flow path 92 adjusts the ratio of the path length to the path cross-sectional area while taking into account the elasticity of the wall of the pressure chamber 84, thereby tuning the resonant frequency of the flowing fluid to the frequency of the vibration of the anti-vibration object. In this embodiment, the tuning frequency of the throttling flow path 92 is set to a low frequency of about 10 Hz, which is equivalent to engine vibration.

[0064] The receiving space 66 of the partition member 40 communicates with the pressure chamber 84 through the first central through-hole 50 and the first peripheral through-hole 52, and with the balance chamber 86 through the second central through-hole 58 and the second peripheral through-hole 60. Furthermore, the movable diaphragm 68 disposed in the receiving space 66 is subjected to hydraulic pressure from the pressure chamber 84 on its upper surface and hydraulic pressure from the balance chamber 86 on its lower surface. Therefore, if a relative internal pressure difference is generated between the pressure chamber 84 and the balance chamber 86, a force in the vertical direction acts on the movable diaphragm 68, causing it to deform or displace. The resonant frequency of the flexural deformation of the movable diaphragm 68 is set to a higher frequency than the tuning frequency of the throttling path 92, corresponding to the vibration frequency of the vibration-damping object, and it actively deforms in a resonant state based on the input of the vibration of the vibration-damping object.

[0065] The gap 80 located on the outer periphery of the movable membrane 68 is connected to the pressure chamber 84 through the connecting passage 82, the first central through hole 50, and the first peripheral through hole 52.

[0066] The gap 80 is not connected to the balancing chamber 86 by the sealing structure based on the contact between the sealing part 72 of the movable membrane 68 and the inner surface 65 of the second wall of the receiving space 66. The pressure chamber 84 and the balancing chamber 86 are not connected via the receiving space 66, but are blocked by the movable membrane 68. Furthermore, the sealing structure based on the contact between the sealing part 72 and the inner surface 65 of the second wall does not necessarily have to be limited to completely blocking the flow of fluid, as long as it prevents the flow of fluid that would reduce the vibration damping performance under normal vibration input.

[0067] The engine mount 10, configured as described above, is mounted to the power unit via an inner bracket (not shown) that inserts the first mounting member 12 into the bracket assembly 18, and the second mounting member 14 is mounted to the vehicle body via an outer bracket (not shown) that is externally mounted, thereby assembling the vehicle.

[0068] When the engine mount 10 is assembled in the vehicle, if a low-frequency, large-amplitude vibration, equivalent to engine vibration, is input in the vertical direction between the first mounting member 12 and the second mounting member 14, a change in internal pressure occurs in the pressure chamber 84, which is part of the wall formed by the main rubber elastomer 16. Furthermore, based on the relative pressure difference between the pressure chamber 84 and the balance chamber 86, fluid flow is actively generated between the pressure chamber 84 and the balance chamber 86 through the throttling passage 92 in a resonant state, thereby exerting a vibration damping effect (vibration attenuation effect) based on the fluid flow.

[0069] When a low-frequency, large-amplitude vibration is input, the deformation of the movable diaphragm 68 cannot follow the amplitude of the input vibration. The movable diaphragm 68 is essentially constrained and cannot fully absorb the hydraulic pressure in the pressure chamber 84 caused by its deformation. Therefore, the internal pressure difference between the pressure chamber 84 and the balance chamber 86 is ensured to be relatively large, efficiently generating fluid flow through the throttling path 92, thus advantageously obtaining the vibration damping effect provided by the throttling path 92. Furthermore, when the significantly deformed movable diaphragm 68 strikes the inner surfaces 55 and 65 of the receiving space 66 and is constrained, the small, cushioning protrusions 78 on both the outer and inner surfaces of the movable diaphragm 68 preferentially contact the inner surfaces 55 and 65 of the receiving space 66, thereby reducing the knocking sound during contact.

[0070] If the input is a mid-frequency or high-frequency small-amplitude vibration equivalent to idling vibration, which is higher than the tuning frequency of the throttling circuit 92, then the throttling circuit 92 is essentially blocked by anti-resonance. The movable diaphragm 68 actively flexes and deforms in a resonant state according to the input vibration, absorbing the internal pressure fluctuations of the pressure chamber 84 caused by the vibration input. This avoids the significant increase in stiffness caused by the substantial sealing of the pressure chamber 84, and achieves the vibration damping effect (vibration insulation effect) brought about by low dynamic stiffness.

[0071] When a vehicle experiences significant vibrations, such as when it traverses a step, causing a substantial decrease in the internal pressure of the pressure chamber 84, a force is applied to the upper side of the movable membrane 68, acting on the side that is the pressure chamber 84, based on the relative internal pressure difference between the pressure chamber 84 and the equilibrium chamber 86. For example... Figure 7As shown, under the action of this force, the elastic protrusion 70 of the movable membrane 68 is compressed and contracts in the vertical direction, and the lower surface of the outer peripheral end of the movable membrane 68 is displaced upward. The sealing portion 72 provided at the outer peripheral end of the movable membrane 68 separates upward from the sealing abutment portion 64 of the inner surface 65 of the second wall constituting the receiving space 66, for example, over a substantially circumferential range. In particular, in this embodiment, deformation other than the forming portion of the elastic protrusion 70 in the outer peripheral end of the movable membrane 68 is more suppressed, and the elastic protrusion 70 is efficiently compressed and deformed in the vertical direction. As a result, the sealing portion 72 in the outer peripheral end of the movable membrane 68, including the forming portion of the elastic protrusion 70, is displaced upward over a substantially circumferential range and separates from the sealing abutment portion 64. Thus, the gap 80 provided on the outer peripheral side of the movable membrane 68 communicates with the balance chamber 86 through the second outer peripheral through hole 60, and the overflow passage 94 that communicates the pressure chamber 84 and the balance chamber 86 is configured to include the gap 80 and the communication passage 82. Then, the sealing fluid flows from the balance chamber 86 to the pressure chamber 84 through the overflow passage 94, thereby rapidly reducing or eliminating the pressure drop in the pressure chamber 84 and preventing cavitation caused by the pressure drop. As a result, abnormal noises and vibrations caused by cavitation are prevented, improving the vehicle's quietness and ride comfort.

[0072] The overflow passage 94 is positioned at the outer peripheral end of the movable membrane 68, thus ensuring a larger circumferential length and a larger cross-sectional area compared to the case where it is located in the central portion of the movable membrane, as in existing structures. Consequently, the flow rate of the overflow passage 94 is larger, and the sealed fluid rapidly flows from the balance chamber 86 to the pressure chamber 84, rapidly reducing the negative pressure in the pressure chamber 84. Furthermore, the overflow passage 94 is shorter than the throttling passage 92, and its cross-sectional area is larger relative to its length. The overflow passage 94 has lower flow resistance than the throttling passage 92, ensuring a larger flow rate.

[0073] The elastic protrusion 70 is formed in a pointed shape, so the elastic force increases nonlinearly as the amount of compression deformation increases, making it difficult to generate further compression deformation. Therefore, when the internal pressure of the pressure chamber 84 decreases significantly, the overflow passage 94 is allowed to open rapidly due to the compression deformation of the elastic protrusion 70, while the connection passage 82 is blocked due to excessive deformation of the elastic protrusion 70, thus maintaining the continuity of the overflow passage 94.

[0074] Furthermore, if a significantly large vibration with a substantial amplitude is input, causing a substantial increase in the internal pressure of the pressure chamber 84, the sealing portion 72 is further compressed, and the outer peripheral end of the movable diaphragm 68 can be displaced downwards. In this case, even if the front end face of the elastic protrusion 70 separates from the inner surface 55 of the first wall of the receiving space 66, the protruding front end face of the elastic protrusion 70 is formed into a pointed spherical crown shape, thereby reducing the knocking sound when it abuts against the inner surface 55 of the first wall again.

[0075] exist Figure 8 In this paper, as a second embodiment of a fluid-sealed vibration damping device constructed according to the present invention, an engine mount 100 for a motor vehicle is shown. In the following description, components and parts that are substantially the same as those in the first embodiment are omitted from the description by using the same reference numerals in the drawings.

[0076] The engine mount 100 has a configuration in which a movable membrane 102 is disposed in the receiving space 66 of the partition member 104. The movable membrane 102 does not have the elastic protrusion 70 shown in the first embodiment at its outer peripheral end, and the upper surface of the outer peripheral end is formed as a flat surface.

[0077] The first partition plate 106 constituting the partition member 104 has a plurality of grooves 108 opening on the inner surface of the wall (first inner wall surface 55) on the side of the pressure chamber 84 of the receiving space 66. The grooves 108 extend radially in the outer peripheral portion of the receiving space 66 and open toward the first outer peripheral through hole 52 at their inner peripheral ends. In other words, it can also be understood that a plurality of radially extending and downwardly projecting ridges are provided on the inner surface of the wall (first inner wall surface 55) on the side of the pressure chamber 84 of the receiving space 66, and grooves 108 opening downwardly are formed between the circumferential of the plurality of ridges. That is, the ridges are integrally formed with the first partition plate 106 and are formed as rigid ridges. In addition, the ridges can be elastic ridges, or the plurality of grooves 108 can be formed, for example, by later fixing to elastic ridges separately formed from the first partition plate 106.

[0078] Regarding the inner surface 55 of the first wall of the accommodating space 66, the portion circumferentially offset from the groove 108 abuts against the upper surface of the outer peripheral end of the movable membrane 102. Thus, the outer peripheral end of the movable membrane 102, in the portion circumferentially offset from the groove 108, is clamped vertically by the partition member 104. Therefore, the portion of the outer peripheral end of the movable membrane 102 that abuts against the first partition plate 106, circumferentially offset from the groove 108, forms the abutting portion of this embodiment.

[0079] By arranging a movable membrane 102 in the receiving space 66, the lower opening of the groove 108 is covered by the movable membrane 102, and the radially extending communication passage 110 is formed by the groove 108. As for the passage 110, the inner peripheral end communicates with the pressure chamber 84 through the first outer peripheral through hole 52, and the outer peripheral end communicates with the gap 80 provided on the outer peripheral side of the movable membrane 102.

[0080] Similar to the first embodiment, when the internal pressure of the pressure chamber 84 of the engine bracket 100 constructed according to this embodiment decreases significantly due to vibration input, the pressure chamber 84 and the balance chamber 86 are connected by an overflow path (not shown) comprising a gap 80 and a connecting path 110. That is, if the internal pressure of the pressure chamber 84 decreases significantly, the force applied towards the pressure chamber 84 side by the relative pressure difference between the pressure chamber 84 and the balance chamber 86 acts on the movable diaphragm 102, and the abutment portion at the outer peripheral end of the movable diaphragm 102 is compressed in the vertical direction. As a result, the outer peripheral end of the movable diaphragm 102 is displaced towards the pressure chamber 84 side, and the sealing portion 72 of the movable diaphragm 102 separates from the sealing abutment portion 64 of the inner wall surface (second inner wall surface 65) on the balance chamber 86 side constituting the receiving space 66. As a result, the gap 80, which communicates with the pressure chamber 84 through the connecting passage 110, communicates with the balance chamber 86 through the sealing part 72 and the sealing abutment part 64 and the second peripheral through hole 60. The overflow passage connecting the pressure chamber 84 and the balance chamber 86 is configured to include the gap 80 and the connecting passage 110. Moreover, the sealed fluid flows from the balance chamber 86 to the pressure chamber 84 through the overflow passage, thereby suppressing the decrease in internal pressure of the pressure chamber 84 and preventing the formation of cavitation.

[0081] In the first embodiment, an elastic protrusion 70 is provided in the movable membrane 68, and a protrusion and a notch are provided in the overlapping portion of the outer peripheral portion of the movable membrane 68 toward the inner surface 55 of the first wall. Thus, a connecting passage 82 and an abutting portion are formed. However, as in this embodiment, a connecting passage 110 and an abutting portion can also be formed by providing a protrusion and a notch in the clamping portion of the movable membrane 102 in the separating member 104.

[0082] exist Figure 9The diagram shows a partition member 120 in an engine mount as a third embodiment of a fluid-sealed vibration damping device constructed according to the present invention. Furthermore, the structure of the fluid-sealed vibration damping device in this embodiment, except for the partition member 120, can be the same as in the first embodiment, and therefore is omitted from the diagram. However, the shape of the partition member 120 and the movable membrane 122 housed within it are the same as in the first embodiment as in the partition member 40 and the movable membrane 68, but the movable membrane 122 in this embodiment differs from the movable membrane 68 in the first embodiment in, for example, in terms of deformation rigidity in various parts. Therefore, in this embodiment, an overflow path 124 appears in a manner different from that in the first embodiment.

[0083] Specifically, for example, in the first embodiment, by changing the material, size, compression ratio of the assembly state of the movable membrane 68 and the elastic protrusion 70, the elastic protrusion 70 is easily compressed and deformed, and the outer peripheral end of the movable membrane 68 is raised from the sealing contact 64 throughout, thus creating an overflow passage 94. However, in this embodiment, the elastic deformation characteristics of the movable membrane 122, including the elastic protrusion 126, are different from those in the first embodiment.

[0084] In this embodiment, the elastic deformation when a relative pressure difference is applied to the movable membrane 122 on both sides tends to manifest as elastic deformation in the flexural direction of the movable membrane 122, rather than as compressive deformation in the protruding direction of the elastic protrusion 126. Therefore, when, for example, the internal pressure of the pressure chamber 84 decreases, the movable membrane 122 is subjected to an upward force due to the relative internal pressure difference between the pressure chamber 84 and the balance chamber 86, as... Figure 9 As shown, the portion of the movable membrane 122 at the outer peripheral end where the elastic protrusions 126 are not provided (the middle portion of adjacent elastic protrusions 126 in the circumferential direction, where it is difficult to apply the deformation binding force brought by the elastic protrusions 126) elastically flexes and deforms in an upward bulging manner. Figure 10 The movable membrane 122 is shown in the above-described deformed state. Furthermore, in... Figure 10 The diagram of the buffer conflict 78 is omitted.

[0085] That is, such as Figure 9 As shown, at the location where the elastic protrusion 126 is formed at the outer peripheral end of the movable membrane 122, the elastic protrusion 126 abuts against the inner wall surface (first inner wall surface 55) on the side of the pressure chamber 84 in the receiving space 66, and the sealing portion 72 abuts against the inner wall surface (second inner wall surface 65) on the side of the balance chamber 86 in the receiving space 66 (see reference). Figure 9 (On the right side). On the other hand, as well as Figure 10As shown, between the elastic protrusions 126, 126 at the outer peripheral end of the movable membrane 122, the sealing portion 72 deforms upward from the inner wall surface (second inner wall surface 65) on the side of the accommodating space 66. Thus, by providing an upwardly deformable portion 128 between the elastic protrusions 126, 126 at the outer peripheral end of the movable membrane 122, a raised portion 130 is provided in the sealing portion 72 at a circumferential position corresponding to the deformable portion 128, protruding from the second inner wall surface 65. Then, at the position where the raised portion 130 is formed, the contact between the sealing portion 72 and the sealing contact portion 64 is released, and the gap 80 and the accommodating chamber 86 are connected through the gap created by the raised portion 130.

[0086] Thus, in this embodiment, the gap connecting the gap 80 and the balance chamber 86 is provided at the same circumferential position as the elastic protrusions 126, 126, thereby providing a discontinuous arrangement over the entire circumferential range. Consequently, by configuring the overflow passage 124, which includes the gap 80 and the connecting passage 82, the pressure chamber 84 and the balance chamber 86 are connected, preventing cavitation.

[0087] In the engine bracket of this embodiment, which has the partition member 120 with the structure described above, the same effect as in the first embodiment can be achieved. In particular, unlike the first embodiment, even when the deformation rigidity of the elastic protrusion 126 is relatively large compared to the movable membrane 122, the elastic protrusions 126, 126 in the outer peripheral end of the movable membrane 122 deform circumferentially (deformation portion 128), which can generate a raised portion 130 in the sealing portion 72 and make the overflow passage 124 connected.

[0088] The embodiments of the present invention have been described in detail above, but the present invention is not limited to this specific description. For example, the elastic protrusion 70 may have a certain length in the circumferential direction and can be formed into a shape that extends continuously in the circumferential direction for a predetermined length. In addition, for example, by forming a plurality of grooves that are partially in the circumferential direction in the annular protrusion, it is also possible to make these grooves circumferentially form elastic protrusions.

[0089] The through-hole connecting the pressure chamber 84 and the receiving space 66 may not have a first central through-hole 50 and a first peripheral through-hole 52, for example, it may only have a first peripheral through-hole 52. The through-hole connecting the balancing chamber 86 and the receiving space 66 may not have a second central through-hole 58 and a second peripheral through-hole 60, for example, it may only have a second peripheral through-hole 60.

[0090] The specific sealing structure based on the pressing of the sealing part against the sealing contact is not particularly limited as long as it is a structure that fluid-tightly seals the space between the sealing part and the sealing contact. Specifically, for example, the contact surface of the sealing part against the sealing contact is formed as a flat surface, and a sealing protrusion that protrudes continuously from the sealing contact along the circumferential direction presses against the flat surface of the sealing part, thereby sealing the space between the sealing part and the sealing contact. Furthermore, as long as fluid tightness can be ensured, the contact surfaces of both the sealing part and the sealing contact can be flat surfaces.

[0091] Furthermore, the deformation portion and specific deformation method within the movable membrane are not limited. For example, the central portion of the movable membrane can deform, and by propagating this deformation to the outer periphery, the sealing portion at the outer periphery of the movable membrane separates from the sealing abutment portion in the second partition plate, thereby connecting the pressure chamber and the balance chamber through an overflow path. In the fluid-sealed vibration damping device according to this invention, the deformation rigidity of the movable membrane and the elastic protrusion is not limited to dimensions, shape, etc., nor is the deformation method of the movable membrane and the elastic protrusion limited when the internal pressure of the pressure chamber decreases. Therefore, the shape of the movable membrane can be arbitrarily designed according to the desired vibration damping characteristics, etc. In this invention, a fluid-sealed vibration damping device with a high degree of design freedom can be provided.

[0092] Furthermore, in the third embodiment described above, when the internal pressure of the pressure chamber 84 decreases and an upward force is applied to the movable membrane 68, not only the deformable portion 128, but also the elastic protrusion 126 is sufficiently compressed in the vertical direction by being pressed against the first partition plate 42. The gap between the sealing portion 72 and the sealing contact portion 64 has an annular portion that covers the entire circumference. It is also possible to adopt a configuration where the vertical dimension of the gap increases at the formation position of the raised portion 130 (approximately at the center between adjacent elastic protrusions 126, 126 in the circumferential direction), combining the manner of the first and third embodiments (the size of the gap varies in the circumferential direction).

[0093] Explanation of reference numerals in the attached figures

[0094] 10: Engine mount (first embodiment of fluid-sealed vibration damping device);

[0095] 12: First mounting component;

[0096] 14: Second mounting component;

[0097] 16: Main body rubber elastomer;

[0098] 18: Bracket assembly section;

[0099] 20: Fixed part;

[0100] 22: Large diameter cylinder;

[0101] 24: Small-diameter cylindrical section;

[0102] 26: Recessed area;

[0103] 28: Stop rubber;

[0104] 30: Interlocking rubber;

[0105] 32: Sealing rubber layer;

[0106] 34: Flexible membrane;

[0107] 36: Fixed components;

[0108] 38: Fluid chamber;

[0109] 40: Separating components;

[0110] 42: First partition plate;

[0111] 44: Second partition;

[0112] 46: Zhou Cao;

[0113] 48: Central fovea;

[0114] 50: First central through hole;

[0115] 52: First peripheral through hole;

[0116] 54: Accommodating recesses;

[0117] 55: Inner surface of the first wall;

[0118] 56: First narrow section;

[0119] 58: Second central through hole;

[0120] 60: Second peripheral through-hole;

[0121] 62: Second narrow section;

[0122] 64: Sealing contact part;

[0123] 65: Inner surface of the second wall;

[0124] 66: Accommodation space;

[0125] 68: Movable membrane;

[0126] 70: Elastic protrusion (abutment part);

[0127] 72: Sealing part;

[0128] 74: Peripheral lip (sealed lip);

[0129] 76: Inner lip (sealed lip);

[0130] 78: Conflicts arise gradually;

[0131] 80: Gap;

[0132] 82: Connecting path;

[0133] 84: Pressure chamber;

[0134] 86: Balance Chamber;

[0135] 88: First connection port;

[0136] 90: Second connecting port;

[0137] 92: Streamline traffic flow;

[0138] 94: Overflow path;

[0139] 100: Engine mount (second embodiment of fluid-sealed vibration damping device);

[0140] 102: Movable membrane;

[0141] 104: Separating components;

[0142] 106: First partition plate;

[0143] 108: Groove;

[0144] 110: Connecting route;

[0145] 120: Separating member (third embodiment);

[0146] 122: Movable membrane;

[0147] 124: Overflow path;

[0148] 126: Elastic protrusion;

[0149] 128: Deformed part;

[0150] 130: The raised part.

Claims

1. A fluid-sealed vibration damping device, wherein a pressure chamber (84) and a balance chamber (86) are separated by a partition member (40, 104, 120), and a movable membrane (68, 102, 122) is housed in a receiving space (66) formed in the partition member (40, 104, 120), wherein, The outer peripheral end of the movable membrane (68, 102, 122) includes: an abutment portion that partially abuts against the inner wall surface (55) of the pressure chamber (84) side of the receiving space (66) in the circumferential direction; and a sealing portion (72) that abuts against the inner wall surface (65) of the balance chamber (86) side of the receiving space (66) over the entire circumference. The outer periphery of the movable membrane (68, 102, 122) is supported by the separating member (40, 104, 120). A gap (80) is provided between the outer peripheral surface of the movable membrane (68, 102, 122) and the inner peripheral surface of the receiving space (66), and, At the outer periphery of the movable membrane (68, 102, 122), a connecting passage (82, 110) is provided on the inner wall surface (55) of the pressure chamber (84) facing the receiving space (66) at a position away from the abutment portion, communicating with the gap (80). The sealing portion (72) is separated from the inner wall surface (65) of the accommodating space (66) on the side of the balancing chamber (86) by the pressure difference between the pressure chamber (84) and the balancing chamber (86) in a substantially circumferential range, thereby constituting an overflow passage (94, 124) connecting the pressure chamber (84) and the balancing chamber (86) including the gap (80) and the connecting passage (82, 110).

2. The fluid-sealed vibration damping device according to claim 1, wherein, At the outer peripheral end of the movable membrane (68, 122), a plurality of elastic protrusions (70, 126) protruding toward the pressure chamber (84) are provided in the circumferential direction. The elastic protrusion (70, 126) abuts against the inner wall surface (55) of the pressure chamber (84) side of the receiving space (66) in the partition member (40, 120) to form an abutment portion. The connecting passage (82) is formed circumferentially between the plurality of elastic protrusions (70, 126).

3. The fluid-sealed vibration damping device according to claim 2, wherein, The pressure difference between the pressure chamber (84) and the balance chamber (86) affects the movable membrane (68, 122). The sealing part (72) at the outer peripheral end of the movable membrane (68, 122) moves away from the inner wall surface (65) of the balance chamber (86) side of the receiving space (66) in the circumferential direction of the elastic protrusion (70, 126). While maintaining the contact state between the inner wall surface (55) of the pressure chamber (84) side and the elastic protrusion (70, 126), and the inner wall surface (65) of the balance chamber (86) side and the sealing part (72), the overflow path (94, 124) appears at the formation location of the elastic protrusion (70, 126).

4. The fluid-sealed vibration damping device according to claim 2 or 3, wherein, The elastic protrusions (70, 126) are formed into a pointed shape that tapers toward the protruding front end.

5. The fluid-sealed vibration damping device according to claim 2 or 3, wherein, The protruding front end face of the elastic protrusion (70, 126) is formed as a spherical crown-shaped curved surface.

6. The fluid-sealed vibration damping device according to any one of claims 1 to 3, wherein, The partition member (104) has a plurality of grooves (108) that open on the outer periphery of the inner wall surface (55) on the side of the pressure chamber (84) in the receiving space (66). The outer peripheral end of the movable membrane (102) and the inner wall surface (55) of the pressure chamber (84) side of the receiving space (66) abut against each other at the portion circumferentially offset from the groove (108), and, The connecting path (110) is formed by the groove (108).

7. The fluid-sealed vibration damping device according to any one of claims 1 to 3, wherein, The outer peripheral end of the movable membrane (68, 102, 122) has a sealing lip (74, 76) that protrudes toward the balance chamber (86) and is continuous throughout the circumference. The sealing lip (74, 76) abuts against the inner wall surface (65) of the balancing chamber (86) side of the receiving space (66) over the entire circumference.

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