Fluid-filled vibration isolation device

Abstract

To provide a fluid-sealed vibration isolator having a novel structure that can prevent leak of liquid between opposite end parts of an orifice passage with a simple structure.SOLUTION: In a partitioning member 58, an accommodation region 66 for a membrane 64 and an orifice passage 96 are formed between mating surfaces of a first member 60 and a second member 62. On the membrane 64, an erroneous assembly prevention protrusion 108 protruding an external periphery is formed at a circumferentially asymmetric position. Te erroneous assembly prevention protrusion 108 is accommodated in a compressed state within a protrusion accommodation region 82 formed between opposite end parts of the orifice passage 96, the membrane 64 is thereby assembled to a partitioning member 58 in a front / rear distinguishing state, and leak of liquid between the opposite end parts of the orifice passage 96 is prevented. The first member 60 and the second member 62 are fixed between the accommodation region 66 and the orifice passage 96 by pins at a plurality of points in the circumferential direction. The protrusion accommodation region 82 is closer to a one pin fixing position of pin fixing positions that neighbor each other in the circumferential direction than to a circumferential center between the neighboring pin fixing positions.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a fluid-filled vibration isolator used for a power unit mount of an automobile or the like.

Background Art

[0002] Conventionally, a fluid-filled vibration isolator that utilizes a vibration isolation effect based on the flow action of a fluid enclosed therein has been used for a power unit mount of an automobile or the like. As disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-241930 (Patent Document 1), two liquid chambers in which relative pressure fluctuations occur upon vibration input are formed inside the fluid-filled vibration isolator, and a partition member that partitions the liquid chambers from each other is disposed between the two liquid chambers. Further, a membrane that is deformed by the pressure difference between one of the liquid chambers acting on both surfaces is disposed on the partition member, and an orifice passage that extends in the circumferential direction and communicates the two liquid chambers with each other is provided on the outer peripheral side of the membrane in the partition member. Then, when vibration is input to the fluid-filled vibration isolator, a vibration isolation effect is exhibited by liquid pressure transmission between the liquid chambers due to deformation of the membrane and by the flow of the liquid between the liquid chambers through the orifice passage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the partition member of Patent Document 1 has a structure in which an upper frame member is overlapped on the upper surface of a lower frame member, and the openings of recesses and grooves formed in the lower frame member are covered by the upper frame member, so that an accommodation region for a membrane (elastic partition member) and an orifice passage are formed between the overlapping surfaces of the lower frame member and the upper frame member.

[0005] However, in partition members with such a superimposed structure of two members, liquid leakage can be a problem between the superimposed surfaces of the two members. Specifically, if a short-circuit leak of liquid occurs between the superimposed surfaces of the lower and upper frame members at both ends of orifice passages located adjacent to each other in the circumferential direction of the partition member, it can lead to a decrease in the fluid flow rate in the orifice passage and a drop in liquid chamber pressure, potentially adversely affecting vibration isolation performance.

[0006] To address this problem, one could consider, for example, providing a sealing rubber between the overlapping surfaces of the two partition members to improve the liquid-tightness of the orifice passage. However, this would require a new sealing rubber component, complicating the assembly process and making it difficult to adopt. Another option is to simplify the assembly process by vulcanizing the sealing rubber onto the partition member. However, this would require a new vulcanization molding process for the sealing rubber, inevitably increasing manufacturing costs.

[0007] The problem to be solved by the present invention is to provide a novel fluid-filled vibration isolation device with a simple structure that can prevent short-circuit leakage of liquid between both ends of an orifice passage. [Means for solving the problem]

[0008] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0009] The first embodiment is a partition member placed between two liquid chambers where relative pressure fluctuations occur when vibration is input, and which is applied to both sides. These twoIn a fluid-sealed vibration isolation device, a membrane is provided that deforms due to the pressure difference between two liquid chambers, and an orifice passage is provided on the outer circumference of the membrane, connecting the two liquid chambers, wherein the partition member has an overlapping structure of a first member and a second member, and a membrane housing area and the orifice passage are formed between the overlapping surfaces of the first member and the second member, the membrane has a front and back shape and a projection for preventing misassembly is integrally formed on the outer circumference at an asymmetrical position in the circumferential direction, and the projection for preventing misassembly is housed and positioned in a projection housing area formed between the circumferential ends of the orifice passage between the overlapping surfaces of the first member and the second member, thereby ensuring that the front and back of the membrane are identified and assembled to the partition member, and the membrane The membrane is provided with a thick support portion that extends circumferentially along its outer edge and is supported in contact with the opposing inner surfaces of the first and second members in the membrane's containment area. A projection for preventing misassembly is formed on the outer surface of the support portion and is compressed within the projection containment area, thereby preventing short-circuit leakage of liquid through the overlapping surfaces of the first and second members between the circumferential ends of the orifice passage. The first and second members are directly overlapped and pin-fixed at multiple circumferential points in the region between the membrane's containment area and the orifice passage, and the projection containment area in the partition member is formed closer to either pin fixing position than to the circumferential center of adjacent pin fixing positions in the circumferential direction.

[0010] According to this embodiment, since the anti-misassembly projections protruding from the outer circumference of the membrane are formed in circumferentially asymmetric positions, the anti-misassembly projections are housed and positioned within the projection housing area, allowing the membrane to be easily assembled to the partition member with its front and back sides clearly identified. Therefore, it is possible to prevent the membrane, which has a different shape on its front and back sides, from being mistakenly assembled to the partition member with its front and back sides reversed.

[0011] The projections for preventing misassembly, which identify the front and back sides of the membrane, are housed in projection-receiving areas located circumferentially between both ends of the orifice passage and are compressed between the first and second members. As a result, the projections for preventing misassembly provide a sealing function between the overlapping surfaces of the first and second members, preventing short-circuit leakage of liquid through the overlapping surfaces of the first and second members at both circumferential ends of the orifice passage. In this way, by providing a sealing structure using projections for preventing misassembly, which are integrally formed on the membrane to assemble the membrane to the partition member in a state where the front and back sides are identified, leakage of liquid between both ends of the orifice passage can be prevented with a simple structure with a small number of parts.

[0012] Furthermore, since the fixing force between the first and second members by pin fixation acts close to the projection housing area, the compressive force due to the contact between the opposing inner surfaces of the first and second members can be effectively applied to the misassembly prevention projection housed in the projection housing area. Therefore, the leak prevention effect by the misassembly prevention projection can be effectively obtained between both circumferential ends of the orifice passage.

[0013] The second embodiment is a fluid-filled vibration isolation device as described in the first embodiment, wherein the membrane has a longitudinal membrane shape with a substantially rectangular planar shape having lengths in two orthogonal directions, the first member and the second member are fixed with pins at positions corresponding to the four corners of the membrane, and the projections for preventing misassembly are provided at the longitudinal portion of the membrane.

[0014] According to this embodiment, since the first and second members are pin-fixed on both diagonal sides where the free length of the membrane in a plan view is maximized, the reaction force against the force acting on the partition member due to the membrane striking is efficiently exerted.

[0015] A third embodiment is a fluid-filled vibration isolation device described in the first or second embodiment, wherein the first member and the second member are fixed to the pin only on the inner circumference side of the orifice passage.

[0016] According to this embodiment, since the clamping force can be applied by pin fixing at a closer position to the outer circumferential portion of the membrane, including the misassembly prevention projection, the clamping force is efficiently applied to the support portion of the membrane and the misassembly prevention projection, thereby effectively achieving stable support of the membrane and prevention of liquid leakage between both ends of the orifice passage.

[0017] The fourth embodiment is a fluid-filled vibration isolation device described in any one of the first to third embodiments, wherein the thickness dimension of the misassembly prevention projection is greater than or equal to the thickness dimension of the support portion provided on the outer peripheral edge of the membrane.

[0018] According to this embodiment, since the anti-misassembly projection is compressed between the first member and the second member to the same extent as or greater than the support portion of the membrane, the anti-misassembly projection can effectively prevent liquid leakage through the overlapping surfaces of the first member and the second member.

[0019] The fifth embodiment is a fluid-filled vibration isolation device described in any one of the first to fourth embodiments, wherein the boundary between the membrane housing area and the projection housing area in which the misassembly prevention projection is housed is a continuous surface without any steps on the opposing inner surfaces of the first member and the second member.

[0020] According to this embodiment, at the boundary between the membrane housing area and the projection housing area, the opposing inner surfaces of the first member and the second member are continuous surfaces without steps. As a result, the projections for preventing misassembly can be easily pressed against the opposing inner surfaces of the first member and the second member without any gaps at the boundary between the membrane housing area and the projection housing area, making it difficult for liquid leakage to occur.

[0021] The sixth aspect is the fluid-filled vibration isolator according to any one of the first to fifth aspects, wherein an insertion hole is formed in the central portion of the membrane, and the first member and the second member are directly overlapped and pinned at the central portion through the insertion hole.

[0022] According to this aspect, since the deformation or displacement of the central portion of the membrane is restricted by the pin fixing of the first member and the second member through the insertion hole, the hitting sound or the like caused by the hitting of the membrane against the partition member is suppressed.

[0023] In addition, since the first member and the second member are pinned at the central portion and the periphery of the membrane, respectively, a reaction force against the hitting of the membrane can be efficiently obtained.

[0024] The seventh aspect is the fluid-filled vibration isolator according to any one of the first to sixth aspects, wherein the circumferential width dimension of the misassembly prevention projection is smaller than the circumferential width dimension in the projection accommodation region, and alignment contact projections that contact the circumferential inner surface of the projection accommodation region are provided on both circumferential side surfaces of the misassembly prevention projection.

[0025] According to this aspect, since the circumferential width dimension of the misassembly prevention projection is smaller than the circumferential width dimension in the projection accommodation region, it is possible to prevent the misassembly prevention projection from being strongly compressed in the circumferential direction by being accommodated in the projection accommodation region, and to prevent the sealing performance from deteriorating due to the distorted deformation of the misassembly prevention projection. In addition, since the alignment contact projections provided on both circumferential side surfaces of the misassembly prevention projection contact the circumferential inner surface of the projection accommodation region, the misassembly prevention projection is arranged in a stable accommodation mode in the projection accommodation region, so that the sealing function of the misassembly prevention projection is stably exhibited.

[0026] The eighth aspect is the fluid-filled vibration isolator according to any one of the first to seventh aspects, wherein a seal lip extending in the protruding direction is formed on the surface in the thickness direction of the misassembly prevention protrusion.

[0027] According to this aspect, by pressing the seal lip provided on the misassembly prevention protrusion against the first member and the second member, the sealing performance by the misassembly prevention protrusion compressed between the first member and the second member can be improved.

[0028] The ninth aspect is the fluid-filled vibration isolator according to any one of the first to eighth aspects, wherein the misassembly prevention protrusion is provided with an inclined portion on the end face in the thickness direction by being gradually thickened toward the tip side in the protruding direction.

[0029] According to this aspect, while applying a sufficient compressive force to the misassembly prevention protrusion to achieve the effect of preventing leakage, it is possible to prevent the compressive stress from being unnecessarily applied to the membrane due to the compressive deformation of the misassembly prevention protrusion, and to prevent or reduce the destabilization of the membrane characteristics and the like.

[0030] The tenth aspect is the fluid-filled vibration isolator according to any one of the first to ninth aspects, wherein the membrane is provided with a relief portion that allows a short-circuit communication between the two liquid chambers by separating the outer peripheral edge portion from both the first member and the second member, and the relief portion is provided partially in the circumferential direction.

[0031] According to this aspect, by the short-circuit communication allowed between the two liquid chambers by the relief portion, it is possible to prevent, for example, abnormal noises caused by cavitation resulting from a rapid pressure drop in the liquid chamber.

[0032] The eleventh aspect is the fluid-filled vibration isolator according to any one of the first to tenth aspects, wherein the first member is a partition base member of a molded product, and the second member is a partition plate member of a press-formed product.

[0033] According to this embodiment, since the first member is a partition base member of a molded product, a great degree of freedom in the shape of recesses that constitute the membrane housing area and projection housing area, and grooves that constitute the orifice passages formed in the first member can be obtained. Furthermore, the second member that covers the openings such as recesses that constitute the membrane housing area and projection housing area, and grooves that constitute the orifice passages, is a partition plate member of a press-formed product, so it can be easily formed.

[0034] The twelfth embodiment is a fluid-filled vibration isolation device described in any one of the first to eleventh embodiments, wherein the circumferential separation distance from the misassembly prevention projection is smaller for the communication port to one of the two liquid chambers in the orifice passage compared to the communication port to the other liquid chamber.

[0035] According to this embodiment, the timing of pressure propagation from the communication opening of the orifice passage to the projection for preventing misassembly is slightly staggered between the two sides, which is expected to improve the leak prevention effect of the projection for preventing misassembly. [Effects of the Invention]

[0036] According to the present invention, in a fluid-filled vibration isolation device, short-circuit leakage of liquid between both ends of the orifice passage can be prevented with a simple structure. [Brief explanation of the drawing]

[0037] [Figure 1] Perspective view showing a power unit mount as the first embodiment of the present invention. [Figure 2] Plan view of the power unit mount shown in Figure 1. [Figure 3] Section III-III in Figure 2 [Figure 4] Figure 1 shows an exploded perspective view of the partition member constituting the power unit mount. [Figure 5] Plan view of the partition base member that constitutes the partition member shown in Figure 4. [Figure 6] Bottom view of the partition base member shown in Figure 5. [Figure 7] Figure 5, section VII-VII [Figure 8] Plan view of the partition plate member constituting the partition member shown in Figure 4. [Figure 9] Figure 8: Cross-sectional view of section IX-IX [Figure 10] Plan view of the membrane constituting the partition member shown in Figure 4. [Figure 11] Figure 10: Cross-sectional view between XI and XI [Figure 12] Figure 10 shows the cross-sectional view between XII and XII. [Figure 13] A plan view showing the membrane shown in Figure 10 set on the partition base member shown in Figure 5. [Figure 14] Figure 4 is a longitudinal cross-sectional view of the partition member, corresponding to the XIV-XIV section in Figure 15. [Figure 15] Figure 14: Cross-sectional view between XV and XV [Modes for carrying out the invention]

[0038] Embodiments of the present invention will be described below with reference to the drawings.

[0039] Figures 1 to 3 show a power unit mount 10 for an automobile as a first embodiment of a fluid-sealed vibration damping device with a structure according to the present invention. The power unit mount 10 vibration-damping connects a power unit, including a drive source such as an engine or motor, to the vehicle body, and as shown in Figure 3, has a structure in which a first mounting member 12 and a second mounting member 14 are connected by a main rubber elastic body 16. In the following description, as a general rule, the vertical direction refers to the vertical direction in Figure 3, which is the axis direction of the mount's center; the front-rear direction refers to the vertical direction in Figure 2, which is the direction of the shorter side of the partition member 58, which will be described later; and the left-right direction refers to the left-right direction in Figure 2, which is the direction of the longer side of the partition member 58, which will be described later.

[0040] The first mounting member 12 is made of metal or the like and integrally includes a roughly rectangular cylindrical portion 18 extending in the front-rear direction and a projection 20 projecting downward from the lower wall of the cylindrical portion 18. In this embodiment, the projection 20 has a solid structure, but it may also have a hollow structure with a concave opening that faces upward, for example.

[0041] The second mounting member 14 is a flattened, roughly rounded rectangular tube shape in which the front-to-back dimension is smaller than the left-to-right dimension. The upper part of the second mounting member 14 is composed of a fixing member 22. The fixing member 22 is a flattened, roughly rounded rectangular ring shape, with the upper part being thicker and protruding inward from the lower part. The lower part of the fixing member 22 is thinner than the fixing portion 24 which is the upper part of the fixing member 22, and is a fitting portion 26 that protrudes downward from the outer peripheral end of the fixing portion 24.

[0042] The fixing member 22 of the second mounting member 14 is positioned below and separated from the first mounting member 12, and the first mounting member 12 and the fixing member 22 are connected by the main rubber elastic body 16. The main rubber elastic body 16 has a roughly truncated square pyramidal shape that contracts upward, with its upper end vulcanized and bonded to the protruding portion 20 of the first mounting member 12, and its lower outer peripheral end vulcanized and bonded to the fixing member 22 of the second mounting member 14. The main rubber elastic body 16 is formed as an integrally vulcanized molded product comprising the first mounting member 12 and the fixing member 22 of the second mounting member 14.

[0043] The main rubber elastic body 16 is provided with a recess 28 that opens on its lower surface. The recess 28 is a curved surface whose bottom surface is concave downwards. The recess 28 is formed on the inner circumference of the fixing member 22 of the second mounting member 14 and opens downwards on the inner circumference of the fixing portion 24 of the fixing member 22.

[0044] The cylindrical portion 18 of the first mounting member 12 is covered by a covering rubber 30 integrally formed with the main body rubber elastic body 16. The covering rubber 30 includes a pair of stopper rubbers 32, 32 that protrude outward from the cylindrical portion 18 on both the left and right sides.

[0045] The outer circumferential surface of the fastening member 22 of the second mounting member 14 is covered by a connecting rubber layer 34 integrally formed with the main rubber elastic body 16. The connecting rubber layer 34 is attached to the outer circumferential surface of the fastening member 22 with a substantially constant thickness.

[0046] A sealing projection 36, integrally formed with the main rubber elastic body 16, is fixed to the lower surface of the fitting portion 26 of the fixing member 22. The sealing projection 36 has a tapered shape that narrows radially downwards and protrudes downward from the lower end of the fitting portion 26. It is desirable that the dimension of the sealing projection 36 protruding downward from the fitting portion 26 is greater than the thickness dimension of the connecting rubber layer 34.

[0047] The lower inner circumferential surface of the fitting portion 26 of the fixing member 22 is covered by a fitting rubber layer 38 integrally formed with the main rubber elastic body 16. The upper inner circumferential surface of the fitting portion 26 of the fixing member 22 is covered by a contact rubber 40 integrally formed with the main rubber elastic body 16 and is radially thicker than the fitting rubber layer 38. The contact rubber 40 protrudes inward from the fitting rubber layer 38 and is also fixed to the lower surface of the fixing portion 24. The contact rubber 40 constitutes the outer circumferential wall portion of the opening of the recess 28 in the main rubber elastic body 16.

[0048] A support member 42 is attached to a fastening member 22 fixed to the main rubber elastic body 16. The support member 42 is generally flat and has a roughly rounded rectangular frame shape, and has a connecting portion 44 at its upper end that fits onto the fastening member 22. The connecting portion 44 is fitted and fixed to the outer circumferential surface of a fitting portion 26 covered with a connecting rubber layer 34, thereby connecting the fastening member 22 and the support member 42 to each other, and the fastening member 22 and the support member 42 together constitute a second mounting member 14.

[0049] A seal receiving portion 46 is provided below the connecting portion 44 of the support member 42. The seal receiving portion 46 is radially thicker than the connecting portion 44. The connecting portion 44 protrudes upward from the outer peripheral end of the seal receiving portion 46, and the seal receiving portion 46 and the connecting portion 44 have a continuous surface without any steps on their outer peripheral surfaces. The seal receiving portion 46 is superimposed axially on the fitting portion 26 of the fixing member 22. A seal projection 36 is interposed between the overlapping surfaces of the fitting portion 26 of the fixing member 22 and the seal receiving portion 46 of the support member 42, and the overlapping surfaces of the fixing member 22 and the seal receiving portion 46 are liquid-tightly sealed by the seal projection 36.

[0050] The support member 42 is equipped with a pressing portion 48 that protrudes inward from the lower side of the seal receiving portion 46. The pressing portion 48 is a flat, roughly rounded rectangular ring plate. The protrusion of the pressing portion 48 inward from the support member 42 is larger on the left and right sides, which are the shorter sides of the support member 42, than on the front and rear sides, which are the longer sides of the support member 42.

[0051] A flexible membrane 52 is attached to the support member 42. The flexible membrane 52 is a thin rubber membrane that is flattened in an axial view and has a roughly rounded rectangular shape, and is easily deformable in the thickness direction, at least in its inner circumference. The inner circumference of the flexible membrane 52 is dome-shaped with the central part convex upward, and the surrounding area is groove-shaped with the outer part concave upward. The outer circumference end of the flexible membrane 52 is a clamping portion 54 that is thicker than the inner circumference.

[0052] The flexible membrane 52 is supported by the clamping portion 54 being superimposed from above on the pressing portion 48 of the support member 42 of the second mounting member 14, with the clamping portion 54 being sandwiched and supported between the overlapping surfaces of the pressing portion 48 and the partition member 58, which will be described later. As a result, the flexible membrane 52 is liquid-tightly attached to the support member 42 of the second mounting member 14.

[0053] A liquid-filled region 56, which is liquid-tightly separated from the outside, is defined between the axially opposing surfaces of the main rubber elastic body 16 and the flexible membrane 52. A liquid such as water, ethylene glycol, alkylene glycol, silicone oil, or a mixture thereof is sealed in the liquid-filled region 56. It is desirable that the liquid sealed in the liquid-filled region 56 be incompressible and low viscosity.

[0054] A partition member 58 is provided in the liquid-filled region 56. As shown in Figure 4, the partition member 58 is composed of a partition base member 60 as a first member, a partition plate member 62 as a second member, and a membrane 64 provided between the partition base member 60 and the partition plate member 62.

[0055] As shown in Figures 5 to 7, the partition base member 60 is a thick, roughly rounded rectangular plate with a narrower width in the front-to-back direction than in the left-to-right direction. The partition base member 60 is formed from synthetic resin or metal, and it is desirable that it be a molded product from the viewpoint of obtaining greater design freedom for the membrane housing area 66 and orifice groove 76, which will be described later.

[0056] As shown in Figures 5 and 7, a recessed membrane housing area 66 opening upward is formed on the inner circumference of the partition base member 60. The membrane housing area 66 is roughly rectangular in shape with rounded corners when viewed in the axial direction. Four through-holes 68 are formed in the bottom wall of the membrane housing area 66, penetrating in the thickness direction (vertical direction). The through-holes 68 have a roughly rectangular cross-section and are arranged in two rows each in the front-to-back and left-to-right directions.

[0057] A central fixing pin 70 is provided in the central part of the membrane housing area 66, protruding upward from the bottom wall of the membrane housing area 66. The central fixing pin 70 is integrally formed with the partition base member 60 and has a large-diameter base portion 72 and a small-diameter tip portion 74.

[0058] The partition base member 60 has an orifice groove 76 that extends circumferentially on the outer side of the membrane housing area 66. The orifice groove 76 extends circumferentially for a length of less than one full turn in the portion that is separated from the membrane housing area 66 on the outer side and opens to the upper surface of the partition base member 60. The circumferential ends of the orifice groove 76 are located close together in the circumferential direction of the partition base member 60, and in this embodiment, both are located on one of the long sides of the partition base member 60. The orifice groove 76 is partially widened at two locations in the longitudinal direction, and a lower communication opening 78 is provided at one of the widened portions, penetrating the bottom wall of the orifice groove 76. The outer wall portion of the orifice groove 76 protrudes upward more than the inner wall portion, and the depth dimension of the orifice groove 76 differs between the inner and outer ends.

[0059] Four outer peripheral fixing pins 80a to 80d are provided between the membrane housing area 66 and the orifice groove 76 (on the inner circumferential wall of the orifice groove 76). The outer peripheral fixing pins 80 are small-diameter cylindrical pins extending with a substantially constant circular cross-section. The outer peripheral fixing pins 80 are integrally formed with the partition base member 60 and are provided protruding upward from the outer circumferential wall of the membrane housing area 66. The outer peripheral fixing pins 80 are provided at each corner of the membrane housing area 66, which is a flattened, substantially rounded rectangle in an axial view. All fixing pins provided on the partition base member 60 (the central fixing pin 70 and the four outer peripheral fixing pins 80a to 80d) are located on the inner circumferential side of the orifice groove 76. The four outer peripheral fixing pins 80a to 80d are identical in shape and size except for their formation positions, but they may be different in shape and size from each other.

[0060] A projection-receiving area 82 is formed between the circumferential ends of the orifice groove 76 in the partition base member 60. The projection-receiving area 82 is formed to extend outward (rearward) from the membrane-receiving area 66, and its bottom surface is a continuous surface without steps with respect to the bottom surface of the membrane-receiving area 66, and in this embodiment, it is composed of a single plane. Thus, the projection-receiving area 82 is a recess that is integrally continuous with the membrane-receiving area 66. Therefore, it can also be considered that the membrane-receiving area 66 is widened outward in a part of the circumferential direction, and this widened portion is the projection-receiving area 82 that opens to the upper surface of the partition base member 60. The outer peripheral end of the projection-receiving area 82 is located radially at approximately the same distance as or slightly outward from the outer peripheral ends of both circumferential ends of the orifice groove 76. The outer peripheral end of the projection-receiving area 82 is narrower in the circumferential direction toward the outer circumference. The upper surfaces of the circumferential walls of the projection-receiving area 82 are tapered in the intermediate portion, and the upper surface on the outer circumferential side of the tapered portion is located above the upper surface on the inner circumferential side.

[0061] As shown in Figures 4, 8, and 9, the partition plate member 62 is a plate-shaped member that is flattened in an axial view and has a roughly rounded rectangular shape, and is made of metal, for example, an aluminum alloy or stainless steel press-formed product (pressed fitting). The outer circumference of the partition plate member 62 is located above the inner circumference, and a tapered portion 84 is provided around the entire circumference, connecting the outer circumference and the inner circumference. The lower surface of the partition plate member 62, including the covering portion at the boundary between the membrane housing area 66 and the projection housing area 82, is a continuous surface without any steps.

[0062] The partition plate member 62 has four upper through-holes 86 formed through it in the thickness direction (vertical direction). The upper through-holes 86 are holes with a substantially rectangular cross-section that correspond to the lower through-holes 68 of the partition base member 60, and are arranged in two rows each in the front-to-back and left-to-right directions, similar to the lower through-holes 68.

[0063] A circular central pin insertion hole 88 is formed in the central part of the partition plate member 62, penetrating vertically. The central pin insertion hole 88 is a hole through which the tip 74 of the central fixing pin 70 of the partition base member 60 can be inserted. In addition, four circular outer peripheral pin insertion holes 90a to 90d are formed at the corners of the roughly rectangular partition plate member 62, each penetrating vertically. The outer peripheral pin insertion holes 90 are holes through which the outer peripheral fixing pin 80 of the partition base member 60 can be inserted. In this embodiment, the central pin insertion hole 88 and the outer peripheral pin insertion holes 90 are circular holes of approximately the same diameter, but they may be holes of different diameters or shapes. Both the central pin insertion hole 88 and the outer peripheral pin insertion holes 90 are formed on the inner circumference side of the tapered portion 84 of the partition plate member 62.

[0064] The partition plate member 62 has an upper communication opening 92 that penetrates vertically in a portion of its outer periphery. The upper communication opening 92 has a roughly rectangular cross-section when viewed vertically and is formed in the front-to-back central portion on the short side of the partition plate member 62.

[0065] A pair of relief holes 94, 94 are formed in the partition plate member 62. The relief holes 94 have a roughly rounded rectangular cross-section and penetrate the partition plate member 62 in the vertical direction. The relief holes 94 are positioned in a location corresponding to the relief portions 106, 106 of the membrane 64, which will be described later, and are located on the inner circumference side of the tapered portion 84 and on both outer sides in the long-side direction relative to the upper through-hole 86.

[0066] The partition plate member 62 is fixed to the partition base member 60 by being superimposed on the upper surface of the partition base member 60. Specifically, the partition plate member 62 is superimposed on the partition base member 60 with the tip 74 of the central fixing pin 70 inserted through the central pin insertion hole 88 and the outer peripheral fixing pin 80 inserted through the outer peripheral pin insertion hole 90. The tips of the central fixing pin 70 and the outer peripheral fixing pin 80 that protrude above the partition plate member 62 are then expanded in diameter by means of melting or crimping using laser irradiation, etc., and are axially locked to the periphery of the central pin insertion hole 88 and the outer peripheral pin insertion hole 90, thereby fixing the partition base member 60 and the partition plate member 62 to each other. The lower surface of the partition plate member 62 is in direct contact with the upper surface of the partition base member 60 at multiple points in the circumferential direction by outer peripheral fixing pins 80, at the wall portion separating the membrane housing area 66 and the orifice groove 76 (the inner circumferential wall portion of the orifice groove 76) and the outer circumferential wall portion of the orifice groove 76. The pin fixing positions by the outer peripheral fixing pins 80 are set at the four corners of the membrane housing area 66, which is roughly rectangular in shape with rounded corners in an axial view. Both the central fixing pin 70 and the outer peripheral fixing pins 80 are located on the inner circumferential side of the orifice groove 76, and the pin fixing positions between the partition base member 60 and the partition plate member 62 are set only on the inner circumferential side of the orifice passage 96, which will be described later.

[0067] The partition plate member 62 is superimposed on the upper surface of the partition base member 60, so that the upper opening of the orifice groove 76 is covered by the partition plate member 62, and an orifice passage 96 is formed between the overlapping surfaces of the partition base member 60 and the partition plate member 62. The orifice passage 96 is formed on the outer circumference of the partition member 58, extending circumferentially between the overlapping surfaces of the partition base member 60 and the partition plate member 62, with one end opening upward through the upper communication opening 92 of the partition plate member 62 and the other end opening downward through the lower communication opening 78 of the partition base member 60. The orifice passage 96 extends circumferentially beyond the outer circumference of the membrane housing area 66.

[0068] Furthermore, by superimposing the partition plate member 62 onto the upper surface of the partition base member 60, the upper opening of the membrane housing area 66 is covered by the partition plate member 62. The membrane 64 is then housed in the membrane housing area 66 formed between the overlapping surfaces of the partition base member 60 and the partition plate member 62.

[0069] As shown in Figures 4, 10 to 12, the membrane 64 is a plate-shaped or film-shaped elastic body made of rubber or resin elastomer, and is approximately rectangular in shape with rounded corners when viewed in the axial direction. The membrane 64 has lengths that differ in two orthogonal directions (front-to-back direction and left-to-right direction), and is longitudinally membrane-shaped with the left-to-right direction being longer than the front-to-back direction. At the outer circumferential end of the membrane 64, a thick outer circumferential support portion 98 is formed, extending circumferentially and projecting upward. In addition, a through hole 100 with an approximately circular cross-section that penetrates vertically is formed in the central part of the membrane 64, and an inner circumferential support portion 102 projecting upward is provided around the through hole 100. Between the outer circumferential support portion 98 and the inner circumferential support portion 102 of the membrane 64 is a thin-walled hydraulic pressure absorption portion 104, and deformation in the thickness direction is permitted in the hydraulic pressure absorption portion 104. The membrane 64 has an outer peripheral support portion 98 and an inner peripheral support portion 102 that are approximately the same thickness, while the hydraulic pressure absorption portion 104 is thinner than the outer peripheral support portion 98 and the inner peripheral support portion 102. The membrane 64 has an outer peripheral support portion 98 and an inner peripheral support portion 102 that are formed only on the upper surface, and the lower surface is a substantially flat surface that extends perpendicular to the axis, so the front and back shapes are different from each other.

[0070] As shown in Figures 4 and 10, the outer peripheral support portion 98 of the membrane 64 is not continuous around its entire circumference, but is divided in the circumferential direction at both short sides of the membrane 64. As a result, the membrane 64 has outer peripheral support portions 98a located at one long side and the corners at both ends of that side, and outer peripheral support portions 98b located at the other long side and the corners at both ends of that side, on both sides in the short-side direction relative to the divided portion.

[0071] A relief portion 106 is provided between the outer peripheral support portion 98a and the outer peripheral support portion 98b of the membrane 64 in the circumferential direction. The relief portion 106 is provided in the divided portion of the outer peripheral support portion 98, separate from the outer peripheral support portions 98a and 98b, and is thin-walled like the hydraulic pressure absorption portion 104, allowing deformation in the thickness direction. The relief portion 106 is integrally formed with the hydraulic pressure absorption portion 104 and is continuous with the lower ends of the outer peripheral support portions 98a and 98b. In this embodiment, the relief portion 106 is provided in the front and rear central portions on each short side of the membrane 64.

[0072] The membrane 64 is provided with an anti-misassembly projection 108 that protrudes outward. The anti-misassembly projection 108 protrudes rearward from the long side portion of the membrane 64, and in this embodiment, it protrudes further outward (rearward) from the outer peripheral support portion 98a. The anti-misassembly projection 108 is provided in a circumferentially asymmetrical position, offset to the left with respect to the left-right center of the long side portion of the membrane 64. The membrane 64 has a different shape on its front and back due to the anti-misassembly projection 108 being provided in a circumferentially asymmetrical position and protruding outward. The anti-misassembly projection 108 protrudes from the long side portion of the membrane 64 and is located in the middle of the long side portion, away from the curved corner. Preferably, the anti-misassembly projection 108 is provided at the end of the straight portion of the long side portion of the membrane 64. The misassembly prevention projection 108 has a minimum thickness dimension (the thickness dimension of the part that is not attached to the seal lip 112, described later) that is approximately the same as that of the outer peripheral support parts 98a and 98b. The misassembly prevention projection 108 has a corresponding shape that allows it to be inserted into the projection housing area 82 of the partition base member 60. The circumferential width dimension w2 of the misassembly prevention projection 108 in the part that is not attached to the alignment contact projection 114, described later, is smaller than the circumferential width dimension w1 of the projection housing area 82 of the partition base member 60.

[0073] The upper surface of the misassembly prevention projection 108 includes a tapered surface 110 as an inclined portion. As shown in Figure 12, the tapered surface 110 is an inclined surface that slopes upward toward the protruding tip of the misassembly prevention projection 108 and is provided in the middle portion of the protruding direction of the misassembly prevention projection 108. The misassembly prevention projection 108 gradually becomes thicker toward the protruding tip in the portion where the tapered surface 110 is formed. The inclination angle of the tapered surface 110 may be substantially constant toward the protruding direction of the misassembly prevention projection 108, or it may become larger or smaller toward the protruding tip of the misassembly prevention projection 108. In this embodiment, the tapered surface 110 is located toward the tip side of the center of the protruding direction of the misassembly prevention projection 108.

[0074] The misassembly prevention projection 108 is provided with a seal lip 112 that protrudes from its upper surface. As shown in Figures 10 to 12, the seal lip 112 is located in the widthwise central portion of the misassembly prevention projection 108, extends linearly in the protruding direction (front-to-back direction) of the misassembly prevention projection 108, and is formed continuously over substantially the entire length of the misassembly prevention projection 108. The seal lip 112 has a tapered shape, becoming narrower in the left-to-right direction towards the protruding tip. The protruding tip surface of the seal lip 112 is composed of a plane having a predetermined width in the circumferential direction. The thickness dimension H of the misassembly prevention projection 108 in the portion where the seal lip 112 is formed is greater than the depth dimension of the projection housing area 82 in the partition base member 60. The thickness dimension of the misassembly prevention projection 108 is set to be greater than or equal to the thickness dimension of the membrane 64 in the formed portions of the outer peripheral support parts 98a and 98b, and the thickness dimension H of the misassembly prevention projection 108 in the formed portion of the seal lip 112 is set to be greater than the thickness dimension h of the membrane 64 in the formed portions of the outer peripheral support parts 98a and 98b. The upward projection height dimension of the seal lip 112 is set to be approximately constant in the projection direction of the misassembly prevention projection 108.

[0075] The misassembly prevention projection 108 is provided with alignment contact projections 114 that protrude from its side. As shown in Figure 10, the alignment contact projections 114 protrude from the misassembly prevention projection 108 on both sides in the circumferential direction (left-right direction) and extend linearly in the vertical direction. In this embodiment, the alignment contact projections 114 are provided at only one location in the direction of protrusion of the misassembly prevention projection 108, but for example, they may be provided at multiple locations that are separated from each other in the direction of protrusion of the misassembly prevention projection 108. The alignment contact projections 114 are provided at approximately the same position in the front-rear direction on both the left and right sides of the misassembly prevention projection 108. The distance w3 between the protruding tips of the alignment contact projections 114 is greater than the circumferential width dimension w1 of the projection housing area 82 in the partition base member 60. The alignment contact projection 114 is preferably tapered, becoming narrower in the front-to-back direction towards its protruding tip. In this embodiment, it has a roughly semicircular cross-sectional shape and extends in the vertical direction.

[0076] As shown in Figure 13, the membrane 64 is housed in the membrane housing area 66 of the partition base member 60. The membrane 64 is positioned perpendicular to the axis of the partition base member 60 by inserting the base 72 of the central fixing pin 70 into the insertion hole 100.

[0077] With the membrane 64 housed in the membrane housing area 66 of the partition base member 60, the partition plate member 62 is fixed to the partition base member 60, so that, as shown in Figures 14 and 15, the membrane 64 is positioned between the overlapping surfaces of the partition base member 60 and the partition plate member 62. The membrane 64 abuts against the opposing inner surfaces of the partition base member 60 and the partition plate member 62 at the outer peripheral support portions 98a, 98b and the inner peripheral support portion 102, and is compressed and sandwiched axially between the partition base member 60 and the partition plate member 62. The hydraulic pressure absorbing portion 104 of the membrane 64 is in contact with the partition base member 60 and overlapping with it, while being separated downward from the partition plate member 62, allowing upward deformation. The partition plate member 62 abuts from above against the base 72 of the central fixing pin 70, which is inserted into the insertion hole 100 of the membrane 64, and the partition base member 60 and the partition plate member 62 are directly superimposed on each other through the insertion hole 100 and fixed with a pin.

[0078] When the membrane 64 is housed in the membrane housing area 66, the projection 108 for preventing misassembly of the membrane 64 is housed in a projection housing area 82 formed between the overlapping surfaces of the partition base member 60 and the partition plate member 62.

[0079] Since the circumferential width dimension of the misassembly prevention projection 108 is smaller than that of the projection housing area 82, a gap is formed between the misassembly prevention projection 108 and the inner surface of the circumferential wall of the projection housing area 82, as shown in an enlarged view in Figure 13. In addition, the alignment contact projections 114 that protrude from the side of the misassembly prevention projection 108 in the circumferential direction are in contact with the inner surface of the circumferential wall of the projection housing area 82, and the misassembly prevention projection 108 is positioned in the circumferential direction within the projection housing area 82 by the alignment contact projections 114. In this way, because the misassembly prevention projection 108 does not directly contact the inner surface of the wall of the projection housing area 82 but contacts it via the alignment contact projections 114, a strong circumferential compressive force does not act on the misassembly prevention projection 108, and distorted deformation of the misassembly prevention projection 108 is prevented. Therefore, the sealing performance achieved by sandwiching the misassembly prevention projection 108 vertically between the partition base member 60 and the partition plate member 62 is stabilized, and deformation of the misassembly prevention projection 108 is prevented from affecting the deformation characteristics of the membrane 64.

[0080] Since the membrane 64 has different shapes on its front and back sides, incorrect assembly with the partition base member 60 in the wrong orientation is prevented. Specifically, the membrane 64 has an assembly prevention projection 108 integrally formed at an asymmetrical position in the circumferential direction. As the assembly prevention projection 108 is accommodated in the projection-accommodating area 82 of the partition base member 60, the membrane 64 is assembled to the partition base member 60 with the correct orientation and front and back sides identified. In other words, even if one attempts to assemble the membrane 64 to the partition base member 60 in the wrong orientation, the assembly prevention projection 108 cannot be accommodated in the projection-accommodating area 82, thus preventing the membrane 64 from being assembled to the partition base member 60 in the wrong orientation.

[0081] In this embodiment, when the membrane 64 is assembled to the partition member 58 housed in the membrane housing area 66, the lower surface of the membrane 64 abuts against the bottom surface of the membrane housing area 66, and the upper surface of the membrane 64 is separated downward from the partition plate member 62. Therefore, if the membrane 64 is assembled to the partition member 58 in the wrong orientation, it may affect the deformation of the hydraulic pressure absorption section 104 during vibration input, potentially preventing the desired characteristics (vibration damping performance, spring characteristics, etc.) from being fully exhibited. In this regard, the power unit mount 10 ensures that the orientation of the membrane 64 is determined by housing the misassembly prevention projection 108 in the projection housing area 82, thereby enabling the desired characteristics to be obtained with high reliability.

[0082] The misassembly prevention projection 108 abuts against the opposing inner surfaces of the partition base member 60 and the partition plate member 62 and is housed in the projection housing area 82 in a compressed state in the vertical direction, ensuring a liquid-tight seal between the misassembly prevention projection 108 and the contact surfaces of the partition base member 60 and the partition plate member 62. In particular, the misassembly prevention projection 108 is pressed against the partition base member 60 and the partition plate member 62 at the portion where the seal lip 112 is formed, ensuring a higher level of liquid tightness at the contact portion between the seal lip 112 and the partition base member 60 and the partition plate member 62.

[0083] Since the projection-receiving area 82 is formed between both ends of the orifice groove 76 in the partition base member 60, a sealing mechanism by the misassembly prevention projection 108 is provided between the orifice groove 76 in the circumferential direction. This prevents short-circuit leakage of liquid through the overlapping surfaces of the partition base member 60 and the partition plate member 62 between both ends of the orifice passage 96.

[0084] The tapered portion 84 of the partition plate member 62 is pressed against the tapered surface 110 provided on the upper surface of the misassembly prevention projection 108. As a result, the misassembly prevention projection 108 is more likely to deform toward the tip at least in the portion where the tapered surface 110 is formed and further toward the tip (outer circumference), while deformation toward the base (inner circumference) is less likely. Therefore, even if the misassembly prevention projection 108 deforms by bulging in a direction perpendicular to the vertical due to vertical compression, the deformation of the misassembly prevention projection 108 is less likely to affect the deformation characteristics of the membrane 64 (hydraulic pressure absorption portion 104).

[0085] The pin fixing position of the partition base member 60 by the outer peripheral fixing pin 80a is set closer to the projection housing area 82 than the pin fixing position of the outer peripheral fixing pin 80d adjacent to the outer peripheral fixing pin 80a in the circumferential direction. In other words, the projection housing area 82 is formed closer to the pin fixing position of the outer peripheral fixing pin 80a than to the circumferential center between the pin fixing position of the outer peripheral fixing pin 80a and the pin fixing position of the outer peripheral fixing pin 80d adjacent to the projection housing area 82 in the circumferential direction. As a result, the fixing force between the partition base member 60 and the partition plate member 62 by pin fixing using the outer peripheral fixing pin 80a is efficiently exerted as a vertical compressive force on the misassembly prevention projection 108 housed in the projection housing area 82. Preferably, the distance d1 between the left and right centers of the projection housing area 82 (projection 108 for preventing incorrect assembly) and the left and right centers of the outer peripheral fixing pin 80a is smaller than 1 / 3 of the distance d2 between the left and right centers of adjacent outer peripheral fixing pins 80a and 80d in the circumferential direction.

[0086] The protruding tip surface of the misassembly prevention projection 108 may be in contact with the inner surface of the outer peripheral wall of the projection housing area 82, but in this embodiment, there is a gap between them in the front-rear direction. This prevents the misassembly prevention projection 108 from being pressed inward, which would affect the deformation characteristics of the membrane 64.

[0087] The partition member 58, having the structure described above, is arranged in the liquid-filled region 56 as shown in Figure 3. Specifically, the partition member 58 is fixed to the second mounting member 14 by being sandwiched between the fixing portion 24 of the fixing member 22 and the pressing portion 48 of the support member 42 in the axial direction, and is positioned in the axial direction between the main rubber elastic body 16 and the flexible membrane 52.

[0088] The upper surface of the outer periphery of the partition member 58 is in contact with the fixing portion 24 of the fixing member 22 via the contact rubber 40, thereby sealing the overlapping surface between the upper surface of the partition member 58 and the fixing portion 24 in a liquid-tight manner. The clamping portion 54 of the flexible membrane 52 is sandwiched between the lower surface of the outer periphery of the partition member 58 and the pressing portion 48 of the support member 42, thereby sealing the overlapping surface between the lower surface of the partition member 58 and the pressing portion 48 in a liquid-tight manner. As a result, the liquid-filled region 56 is divided into upper and lower parts of the partition member 58, and two liquid chambers are formed on both the upper and lower sides of the partition member 58. Specifically, on the upper side of the partition member 58, a pressure-receiving chamber 116 is formed as one of the liquid chambers, where a portion of the wall is composed of the main body rubber elastic body 16, and internal pressure fluctuations occur when vibration is input. Furthermore, below the partition member 58, a balance chamber 118 is formed as the other liquid chamber, where a portion of the wall is composed of a flexible membrane 52, and volume changes are easily permitted by the deformation of the flexible membrane 52. As can be understood from the fact that the pressure-receiving chamber 116 and the balance chamber 118 constitute a liquid-filled region 56, liquid is sealed inside them. Relative pressure fluctuations are generated in the pressure-receiving chamber 116 and the balance chamber 118 when vibration is input.

[0089] The orifice passage 96 has one end, formed by an upper communication port 92, which communicates with the pressure-receiving chamber 116, and the other end, formed by a lower communication port 78, which communicates with the balancing chamber 118, thus connecting the pressure-receiving chamber 116 and the balancing chamber 118 to each other. When vibration input between the first mounting member 12 and the second mounting member 14 causes a relative pressure fluctuation between the pressure-receiving chamber 116 and the balancing chamber 118, liquid flow occurs through the orifice passage 96 between the pressure-receiving chamber 116 and the balancing chamber 118, and a vibration isolation effect (vibration damping effect) based on the action of liquid flow is exerted. The resonance frequency (tuning frequency) of the flowing liquid in the orifice passage 96 is set to the frequency of the vibration to be isolated, so that when the vibration to be isolated is input, liquid flow through the orifice passage 96 actively occurs in a resonant state.

[0090] When liquid flows through the orifice passage 96, a sealing mechanism using misassembly prevention projections 108 is provided between both ends of the orifice passage 96, thereby preventing short-circuit leakage of liquid through the overlapping surfaces of the partition base member 60 and the partition plate member 62. This ensures a large amount of liquid flow through the orifice passage 96 between the pressure-receiving chamber 116 and the equilibrium chamber 118, allowing the vibration damping effect based on the liquid flow action to be efficiently exerted. By using misassembly prevention projections 108 for sealing between both ends of the orifice passage 96, the performance of the orifice passage 96 can be improved with a simple structure.

[0091] The upper communication port 92 of the orifice passage 96 to the pressure-receiving chamber 116 is located at a smaller circumferential distance from the misassembly prevention projection 108 compared to the lower communication port 78 of the orifice passage 96 to the equilibrium chamber 118. In this way, the circumferential distances from the misassembly prevention projection 108 to the upper and lower communication ports 92 and 78 are different, which can cause the timing of pressure propagation from each communication port 92 and 78 of the orifice passage 96 to the misassembly prevention projection 108 to be staggered. This can be expected to improve the leak prevention effect compared to when the timing of pressure propagation is the same.

[0092] The hydraulic pressure absorbing section 104 of the membrane 64 is subjected to the hydraulic pressure of the pressure-receiving chamber 116 through the upper through-hole 86 on its upper surface, and to the hydraulic pressure of the equilibrium chamber 118 through the lower through-hole 68 on its lower surface. When a relative pressure difference is created between the pressure-receiving chamber 116 and the equilibrium chamber 118 due to vibration input, the hydraulic pressure absorbing section 104 elastically deforms in the thickness direction, and the pressure difference between the pressure-receiving chamber 116 and the equilibrium chamber 118 is reduced by the deformation of the hydraulic pressure absorbing section 104. The hydraulic pressure absorbing section 104 is designed to actively deform in a resonant state when vibration input is at a frequency higher than the tuning frequency of the orifice passage 96, thereby exhibiting a hydraulic pressure absorbing effect. Therefore, when the orifice passage 96 is substantially blocked by anti-resonance, the elastic deformation of the hydraulic pressure absorbing section 104 prevents the pressure-receiving chamber 116 from being substantially sealed, and a vibration isolation effect is exhibited by reducing the dynamic spring.

[0093] The relief portion 106 of the membrane 64 is subjected to the hydraulic pressure of the pressure-receiving chamber 116 through the relief holes 94 of the partition plate member 62. When a rapid and significant drop in hydraulic pressure occurs in the pressure-receiving chamber 116, which can cause cavitation, the relief portion 106 is drawn towards the pressure-receiving chamber 116 by the negative pressure of the pressure-receiving chamber 116, separating it from the bottom surface of the membrane housing area 66. As a result, short-circuit liquid flow from the equilibrium chamber 118 to the pressure-receiving chamber 116 is permitted through the outer circumference of the relief portion 106, which is separated from both the partition base member 60 and the partition plate member 62, and through the relief holes 94, and the drop in hydraulic pressure in the pressure-receiving chamber 116 is quickly reduced or eliminated. Therefore, gas phase separation (cavitation) due to the drop in hydraulic pressure in the pressure-receiving chamber 116 is prevented, and the generation of abnormal noise caused by cavitation is prevented. Furthermore, when the internal pressure of the pressure-receiving chamber 116 becomes positive, the relief portion 106 comes into contact with the bottom surface of the membrane housing area 66, thereby preventing short-circuit liquid flow through the outer circumference of the relief portion 106 and preventing a drop in the liquid pressure of the pressure-receiving chamber 116.

[0094] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the relief portion 106 of the membrane 64 and the relief hole 94 of the partition plate member 62 are not essential and can be omitted when abnormal noise due to cavitation is not a problem.

[0095] The alignment contact protrusions 114 may be provided in multiple locations separated from each other in the direction of protrusion of the misassembly prevention protrusion 108. Specifically, for example, if alignment contact protrusions 114 are provided at the tip and base portions of the misassembly prevention protrusion 108, the misassembly prevention protrusion 108 can be positioned more stably in the circumferential direction.

[0096] The upper and lower communication ports 92 and 78 of the orifice passage 96 to the pressure-receiving chamber 116 and the equilibrium chamber 118 may both be located at the ends of the orifice groove 76, or they may both be located in the middle of the orifice groove 76.

[0097] The outer peripheral support portions 98 (98a, 98b) of the membrane 64 may protrude downward in the thickness direction toward the equilibrium chamber 118, or they may protrude on both the upper and lower sides in the thickness direction. The same applies to the inner peripheral support portion 102.

[0098] The specific structures of the first mounting member 12 and the second mounting member 14 are merely illustrative examples, and for example, structures such as those described in International Publication No. 2020 / 208689 can be used as the first and second mounting members. Furthermore, the fluid-filled vibration isolation device may be substantially circular in axial view, as described in Japanese Patent Application Publication No. 2014-219035. [Explanation of symbols]

[0099] 10 Power unit mount (fluid-filled vibration isolation device) 12 First mounting member 14 Second mounting member 16 Main body rubber elastic body 18. Cylindrical part 20 Protrusion 22 Fixing member 24 Fixing part 26 Fitting part 28 recess 30 Coated rubber 32 Stopper rubber 34 Interlocking rubber layer 36 Seal projection 38. Fitting rubber layer 40 Contact rubber 42 Support member 44 Connecting part 46 Seal receiving part 48 Pressing part 52 Flexible membrane 54 Clamping part 56 Liquid-filled area 58 Partition Member 60 Partition base component (first component) 62 Partition plate component (second component) 64 Membrane 66 Membrane Containment Area 68 Inferior perforations 70 Center fixing pin 72 Base 74 Tip 76 Orifice groove 78 Lower communication port 80 (80a~80d) Outer edge fixing pin 82 Protrusion accommodating area 84 Tapered section 86 Superior perforations 88 Center pin insertion hole 90 (90a~90d) Outer circumference pin insertion holes 92 Upper communication port 94 Relief holes 96 Orifice Passage 98(98a,98b) Outer periphery support part (support part) 100 Through hole 102 Inner Circumference Support Section 104 Hydraulic pressure absorption section 106 Relief Pitchers 108 Protrusions to prevent incorrect assembly 110 Tapered surface (inclined section) 112 Seal Lip 114 Alignment contact projection 116 Pressure-receiving chamber (one of the liquid chambers) 118 Equilibrium chamber (the other liquid chamber)

Claims

1. In a fluid-filled vibration isolation device, a partition member is provided between two liquid chambers where relative pressure fluctuations occur during vibration input. The partition member is equipped with a membrane that deforms due to the pressure difference between the two liquid chambers acting on both sides, and an orifice passage is provided on the outer circumference of the membrane, extending circumferentially to connect the two liquid chambers. The partition member has an overlapping structure of a first member and a second member, and the membrane housing area and the orifice passage are formed between the overlapping surfaces of the first member and the second member. The membrane has different shapes on its front and back sides, and a projection for preventing incorrect assembly is integrally formed on the outer circumference at an asymmetrical position in the circumferential direction. The anti-misassembly projection is housed and positioned in a projection-receiving area formed between the circumferential ends of the orifice passage in the overlapping surfaces of the first member and the second member, thereby ensuring that the membrane is assembled to the partition member with its front and back sides identified. The membrane is provided with a thick support portion that extends circumferentially along its outer edge and is supported in contact with the opposing inner surfaces of the first and second members within the membrane's containment area. A projection for preventing misassembly is formed on the outer surface of the support portion and is compressed within the projection containment area, thereby preventing short-circuit leakage of liquid through the overlapping surfaces of the first and second members at both circumferential ends of the orifice passage. The first member and the second member are directly superimposed on each other at multiple points in the circumferential direction in the region between the membrane's housing area and the orifice passage, and are pinned together. A fluid-filled vibration isolation device in which the projection-receiving area of ​​the partition member is formed to be closer to either pin fixing position than to the circumferential center of adjacent pin fixing positions in the circumferential direction.

2. The membrane has a longitudinal membrane shape with a roughly rectangular planar shape having lengths that differ in two orthogonal directions. The first member and the second member are fixed with the pins at positions corresponding to the four corners of the membrane, The fluid-filled vibration isolation device according to claim 1, wherein the projection for preventing incorrect assembly is provided on the long side portion of the membrane.

3. The fluid-filled vibration isolation device according to claim 1 or 2, wherein the first member and the second member are fixed to the pin only on the inner circumference side of the orifice passage.

4. The fluid-filled vibration isolation device according to claim 1 or 2, wherein the thickness dimension of the projection for preventing incorrect assembly is greater than or equal to the thickness dimension of the support portion provided on the outer peripheral edge of the membrane.

5. The fluid-sealed vibration isolation device according to claim 1 or 2, wherein the boundary between the membrane housing area and the projection housing area in which the misassembly prevention projection is housed is a continuous surface without any steps on the opposing inner surfaces of the first member and the second member.

6. A through hole is formed in the central part of the membrane. The fluid-filled vibration isolation device according to claim 1 or 2, wherein the first member and the second member are directly superimposed at their central portions through the insertion hole and fixed with pins.

7. The circumferential width dimension of the projection for preventing incorrect assembly is smaller than the circumferential width dimension of the projection housing area, The fluid-filled vibration isolation device according to claim 1 or 2, wherein alignment contact protrusions are provided on both circumferential sides of the projection for preventing misassembly, and contact the circumferential inner surface of the projection housing area.

8. The fluid-filled vibration isolation device according to claim 1 or 2, wherein the projection for preventing incorrect assembly has a seal lip that extends in the protruding direction on the surface in the thickness direction.

9. The fluid-filled vibration damping device according to claim 1 or 2, wherein the projection for preventing incorrect assembly is provided with an inclined portion at the end face in the thickness direction, by gradually increasing the thickness toward the tip in the protruding direction.

10. The fluid-filled vibration isolation device according to claim 1 or 2, wherein the membrane is partially provided with a relief portion in the circumferential direction, the outer peripheral edge of which separates from both the first member and the second member, thereby allowing short-circuit communication between the two liquid chambers.

11. The fluid-filled vibration damping device according to claim 1 or 2, wherein the first member is a partition base member of a molded product, and the second member is a partition plate member of a press-formed product.

12. The fluid-filled vibration isolation device according to claim 1 or 2, wherein the circumferential separation distance from the misassembly prevention projection is smaller for the communication port to one of the two liquid chambers in the orifice passage compared to the communication port to the other liquid chamber.

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