Fluid-sealed vibration isolation device

Abstract

To provide a fluid-sealed vibration isolation device capable of suppressing striking sound generated when a movable part made of an elastic body collides with a first partition wall part and a second partition wall part, and abnormal sound generated due to cavitation with a simple configuration.SOLUTION: When a central movable part 10B of an engine mount 1 is held in a neutral position, no gap is formed between a valve protrusion part 13H and a valve hole part 10C, while, when negative pressure is generated in a pressure-receiving chamber 8, the central movable part 10B moves from the neutral position toward a first partition wall part 12 to deform a first protrusion 10a, thereby forming a gap between the valve protrusion part 13H and the valve hole part 10C, so that the pressure-receiving chamber 8 communicates with an equilibrium chamber 9 through a relief valve 17.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fluid-filled vibration damping device. [Background technology]

[0002] BACKGROUND ART Known fluid-filled vibration-damping devices used in vehicle engine mounts and the like utilize a fluid pressure transmission effect due to elastic deformation of a movable part (see Patent Document 1).

[0003] The fluid-filled vibration damping device described in Patent Document 1 has a pressure-receiving chamber and an equilibrium chamber, each filled with an incompressible fluid, formed on either side of a partition member, and a communication flow path formed in the partition member that connects the pressure-receiving chamber and the equilibrium chamber to each other.

[0004] A storage area is provided inside the partition member, and the communicating flow path is configured to include the storage area, and a movable part that can elastically deform in the direction of communication between the pressure-receiving chamber and the equilibrium chamber in the storage area is arranged in the storage area.

[0005] A compression coil spring is disposed between the wall of the accommodation area on the pressure chamber side and the movable part, and the movable part is pressed against the wall of the accommodation area on the equilibrium chamber side by the compression coil spring. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-71126 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in such a conventional fluid-filled vibration-damping device, when the movable part moves under the influence of fluid pressure and hits the partition member hard, there is a risk of generating a hitting sound.

[0008] Furthermore, if the pressure in the pressure-receiving chamber drops significantly and cavitation occurs in the pressure-receiving chamber, the movable part moves toward the pressure-receiving chamber against the spring force of the compression coil spring, causing fluid to flow through the connecting flow path from the equilibrium chamber to the pressure-receiving chamber, quickly alleviating the pressure drop in the pressure-receiving chamber; however, the need to use a compression coil spring complicates the structure of the fluid-filled vibration-damping device.

[0009] The present invention has been made in response to the above-mentioned problems, and aims to provide a fluid-filled vibration-damping device that can suppress, with a simple configuration, the impact noise that occurs when a movable part made of an elastic body collides with the first partition part and the second partition part, and the abnormal noise that occurs due to cavitation. [Means for solving the problem]

[0010] The present invention is a fluid-filled vibration damping device comprising: a partition member that divides a fluid chamber filled with a fluid into a pressure-receiving chamber and an equilibrium chamber, and that has a first partition wall portion arranged on the pressure-receiving chamber side and a second partition wall portion arranged on the equilibrium chamber side; an orifice passage that is provided in the partition member and that connects the pressure-receiving chamber and the equilibrium chamber; a movable portion that is made of an elastic member arranged between the first partition wall portion and the second partition wall portion and that deflects a central movable portion that is formed to be thinner than its outer periphery to absorb internal pressure fluctuations in the pressure-receiving chamber; and a relief valve that connects the pressure-receiving chamber to the equilibrium chamber when negative pressure is generated in the pressure-receiving chamber, wherein the central movable portion has a plurality of first protrusions that abut on the first partition wall portion and a second partition wall that abut on the second partition wall portion. and a plurality of second protrusions that abut against a portion of the central movable part, and are held in a neutral position when the first protrusions and the second protrusions are not deformed, and the relief valve is configured to include a valve hole provided in the central movable part and a valve protrusion provided in the second partition part and inserted into the valve hole, and when the central movable part is held in the neutral position, no gap is formed between the valve protrusions and the valve hole, while when negative pressure is generated in the pressure receiving chamber, the central movable part moves from the neutral position toward the first partition part and a gap is formed between the valve protrusions and the valve hole, so that the pressure receiving chamber communicates with the equilibrium chamber through the relief valve. [Effects of the Invention]

[0011] As described above, according to the present invention, the impact noise generated when the movable part made of an elastic body collides with the first partition part and the second partition part, and the abnormal noise generated by cavitation can be suppressed with a simple configuration. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a structural diagram of a fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a first partition wall portion, a central movable portion, and a second partition wall portion of a fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a top view of a partition member of a fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 4] FIG. 4 is an enlarged view of a valve projection and its surrounding area in a fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 5] FIG. 5 is a bottom view of the first partition wall of the fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 6] FIG. 6 is an enlarged view of the annular portion of the first partition wall and its surrounding area of ​​a fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 7] FIG. 7 is a top perspective view of the movable part of a fluid-filled type vibration damping device according to one embodiment of the present invention. [Figure 8] FIG. 8 is an enlarged view of the valve hole portion and its surrounding area of ​​the movable portion of a fluid-filled type vibration damping device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] A fluid-filled type vibration damping device according to one embodiment of the present invention is a fluid-filled type vibration damping device comprising: a partition member that separates a fluid chamber filled with fluid into a pressure-receiving chamber and an equilibrium chamber, and has a first partition wall portion arranged on the pressure-receiving chamber side and a second partition wall portion arranged on the equilibrium chamber side; an orifice passage that is provided in the partition member and connects the pressure-receiving chamber and the equilibrium chamber; a movable portion that is made of an elastic member arranged between the first partition wall portion and the second partition wall portion and that is thinner than the outer periphery of the movable portion, and that deflects the central movable portion to absorb internal pressure fluctuations in the pressure-receiving chamber; and a relief valve that connects the pressure-receiving chamber to the equilibrium chamber when negative pressure is generated in the pressure-receiving chamber, The relief valve has a plurality of first protrusions in contact with the first partition portion and a plurality of second protrusions in contact with the second partition portion, and is held in a neutral position when the first protrusions and the second protrusions are not deformed. The relief valve includes a valve hole portion provided in the central movable portion and a valve protrusion portion provided in the second partition portion that is inserted into the valve hole portion. When the central movable portion is held in the neutral position, no gap is formed between the valve protrusions and the valve hole portion, but when negative pressure is generated in the pressure receiving chamber, the central movable portion moves from the neutral position toward the first partition portion and a gap is formed between the valve protrusions and the valve hole portion, and the pressure receiving chamber is connected to the equilibrium chamber through the relief valve.

[0014] As a result, the fluid-filled vibration damping device according to one embodiment of the present invention can suppress, with a simple configuration, the impact noise that occurs when the movable part made of an elastic body collides with the first partition part and the second partition part, and the abnormal noise that occurs due to cavitation. [Example]

[0015] Hereinafter, an embodiment of a fluid-filled type vibration damping device according to the present invention will be described with reference to the drawings. 1 to 8 are diagrams showing a fluid-filled type vibration damping device according to one embodiment of the present invention.

[0016] In Figures 1 to 8, the up / down, front / rear, left / right directions are based on the fluid-filled type vibration damping device when placed in a vehicle, and the front / rear direction of the vehicle is defined as the front / rear direction, the left / right direction of the vehicle (vehicle width direction) is defined as the left / right direction, and the up / down direction of the vehicle (vehicle height direction) is defined as the up / down direction.

[0017] First, the configuration will be described. In Figure 1, an engine mount 1, which is a fluid-filled vibration-damping device installed in a vehicle, is equipped with an elastic vibration-damping rubber 2, and an engine-side mounting member 3 made of metal or the like is attached to the top of the vibration-damping rubber 2.

[0018] The engine-side mounting member 3 is formed in an overall cylindrical shape and has a flange portion 3A at its upper end. The engine-side mounting member 3 has a threaded hole 3B that extends linearly in the axial direction on the central axis and opens to the top surface.

[0019] The engine-side mounting member 3 is attached to an engine (not shown) by bolts (not shown).

[0020] A vehicle body side mounting member 4 made of metal or the like is attached to the vibration-damping rubber 2. The vibration-damping rubber 2 comprises a large diameter cylindrical portion 2A, a small diameter cylindrical portion 2B that is connected to the lower part of the large diameter cylindrical portion 2A via a step and has a smaller diameter and is thinner than the large diameter cylindrical portion 2A, and a truncated cone portion 2C that extends upward from the large diameter cylindrical portion 2A and to which the engine side mounting member 3 is attached.

[0021] The vehicle body side mounting member 4 is composed of the outer peripheries of the large diameter cylindrical portion 2A and the small diameter cylindrical portion 2B, and is attached to a vehicle body side bracket (not shown). The small diameter cylindrical portion 2B is attached to the vehicle body (not shown) via the vehicle body side bracket.

[0022] The engine mount 1 is interposed between the engine and the vehicle body, elastically supports the engine on the vehicle body, and absorbs vibrations transmitted from the engine to the vehicle body with the vibration-proof rubber 2.

[0023] The engine side mounting member 3 and the vehicle body side mounting member 4 are connected by vibration-isolating rubber 2, and the engine side mounting member 3 and the vehicle body side mounting member 4 are integrated with the vibration-isolating rubber 2 by vulcanization molding or the like.

[0024] A recess 2a is formed inside the vibration-proof rubber 2, and the recess 2a has an upper bottom wall portion formed in an upside-down bowl shape, with the diameter gradually decreasing upward.

[0025] A flexible membrane 5 is attached to the lower part of the small diameter cylindrical portion 2B. The flexible membrane 5 is a thin membrane made of rubber, and the outer periphery is formed to be thicker than the inner periphery, and the outer periphery is connected to the small diameter cylindrical portion 2B.

[0026] A fluid chamber 6 is formed between the vibration-proof rubber 2 and the flexible film 5, and the fluid chamber 6 is liquid-tightly isolated from the outside. An incompressible fluid (liquid) such as water, ethylene glycol, or silicone oil is sealed in the fluid chamber 6. Note that the fluid sealed in the fluid chamber 6 is not limited to the liquids exemplified above, and is not limited to any liquid.

[0027] A partition member 7 is provided in the fluid chamber 6, and the outer periphery of the partition member 7 is connected to the inner periphery of the small diameter cylindrical portion 2B.

[0028] The partition member 7 divides the fluid chamber 6 into a pressure-receiving chamber 8 and an equilibrium chamber 9. The pressure-receiving chamber 8 is formed of a space above the partition member 7 and surrounded by the recess 2a and the partition member 7.

[0029] The equilibrium chamber 9 is formed of a space below the partition member 7 and surrounded by the flexible membrane 5 and the partition member 7 .

[0030] The partition member 7 is composed of an approximately cylindrical partition member main body 11, a first partition wall portion 12, and a second partition wall portion 13, and the partition member main body 11, the first partition wall portion 12, and the second partition wall portion 13 are made of metal, synthetic resin, etc.

[0031] An accommodating recess 11A is formed inside the partition member main body 11, and the accommodating recess 11A is open at its upper end and recessed in an annular shape downward from the upper end.

[0032] The accommodation recess 11A accommodates a movable part 10 made of an elastic material such as rubber. The movable part 10 includes an annular part 10A having a thick outer periphery and a disk-shaped central movable part 10B formed inside the annular part 10A.

[0033] The central movable portion 10B is formed to be thinner than the annular portion 10A, and extends inward from the center of the annular portion 10A in the up-down direction.

[0034] The first partition wall portion 12 is formed in a disk shape, and is arranged on the pressure-receiving chamber 8 side of the partition member main body 11. In other words, the first partition wall portion 12 is arranged on the pressure-receiving chamber 8 side of the partition member 7.

[0035] As shown in FIGS. 5 and 6, four peripheral openings 12A are formed in the center of the first partition wall portion 12, and the peripheral openings 12A are partitioned in the circumferential direction by four partition portions 12B.

[0036] An annular portion 12C is connected to the radially inner end of the partition portion 12B, and a central opening 12D is formed in the central portion of the annular portion 12C.

[0037] An orifice inlet portion 12E opens radially outward from the peripheral opening portion 12A, and the orifice inlet portion 12E extends along the circumferential direction of the first partition wall portion 12.

[0038] 1, the second partition wall portion 13 is disposed on the equilibrium chamber 9 side of the partition member main body 11. In other words, the second partition wall portion 13 is disposed on the equilibrium chamber 9 side of the partition member 7.

[0039] As shown in Figures 1 and 3, the second partition portion 13 has an annular bottom wall portion 13A that forms the bottom surface of the accommodating recess 11A, and an annular protrusion portion 13B that is located radially inward from the bottom wall portion 13A and protrudes upward from the bottom wall portion 13A.

[0040] The second partition wall portion 13 has four central openings 13C located radially inward from the protruding portions 13B. The central openings 13C are partitioned in the circumferential direction by four partition portions 13D.

[0041] The second partition wall portion 13 has a disk portion 13E, which is located radially inward of the central opening 13C and is connected to the protrusion 13B by a partition portion 13D.

[0042] As shown in FIG. 3, an orifice inlet portion 11F is formed at the upper end of the partition member body 11, and the orifice inlet portion 11F is configured as a notch extending in the circumferential direction of the partition member body 11.

[0043] The orifice inlet portion 11F faces the orifice inlet portion 12E of the first partition wall portion 12 in the vertical direction.

[0044] A circumferential groove 11G is formed on the outer periphery of the partition member main body 11, and the circumferential groove 11G extends spirally from the orifice inlet portion 11F to the outer periphery of the partition member main body 11. An orifice outlet portion (not shown) consisting of a notch that communicates with the lower part of the circumferential groove 11G is formed on the bottom of the partition member main body 11.

[0045] That is, the upper end of the circumferential groove 11G communicates with the orifice inlet 11F, and the lower end of the circumferential groove 11G communicates with the orifice outlet.

[0046] An orifice passage 14 (see FIG. 1) is formed between the circumferential groove 11G and the small diameter cylindrical portion 2B, extending from the orifice inlet portion 11F to the orifice outlet portion, and the orifice passage 14 connects the pressure-receiving chamber 8 and the equilibrium chamber 9. In other words, the orifice passage 14 is formed in the partition member 7.

[0047] As a result, the fluid sealed in the fluid chamber 6 passes through the orifice passage 14 and travels back and forth between the pressure-receiving chamber 8 and the equilibrium chamber 9, causing liquid column resonance in the fluid flowing through the orifice passage 14.

[0048] When shake vibration, which is a large amplitude, low frequency vibration, is input to the engine mount 1, the vibration is damped by the liquid column resonance of the fluid moving back and forth within the orifice passage 14.

[0049] The equilibrium chamber 9 is provided with a flexible membrane 5, so that when fluid flows from the pressure-receiving chamber 8 to the equilibrium chamber 9 through the orifice passage 14, the flexible membrane 5 expands downward, allowing the equilibrium chamber 9 to receive the fluid flowing from the pressure-receiving chamber 8 to the equilibrium chamber 9.

[0050] 1 and 2, the movable part 10 is disposed between the first partition wall part 12 and the second partition wall part 13. The lower part of the annular part 10A of the movable part 10 is sandwiched between the protruding part 13B and the inner circumferential surface of the accommodating recess 11A, and is positioned in the partition member main body 11.

[0051] 2, a vertical gap 15 is formed between the upper end of the central movable portion 10B and the first partition wall portion 12, and the gap 15 between the upper end of the central movable portion 10B and the first partition wall portion 12 is in communication with the peripheral opening 12A and the central opening 12D. In other words, the pressure-receiving chamber 8 and the gap 15 are in communication with each other via the peripheral opening 12A and the central opening 12D.

[0052] A vertical gap 16 is formed between the lower end of the central movable part 10B and the second partition part 13, and the gap 16 between the lower end of the central movable part 10B and the second partition part 13 is in communication with each other through a central opening 13C. In other words, the equilibrium chamber 9 and the gap 16 are in communication with each other through the central opening 13C.

[0053] When minute amplitude (high frequency range) vibrations are input to the pressure receiving chamber 8, such as when the engine is idling, fluid does not flow between the pressure receiving chamber 8 and the equilibrium chamber 9 through the orifice passage 14, and the central movable part 10B bends under the pressure of the fluid in the pressure receiving chamber 8, causing the central movable part 10B to absorb the internal pressure fluctuations of the pressure receiving chamber 8. In this way, the central movable part 10B absorbs minute amplitude vibrations.

[0054] As shown in FIG. 2, a plurality of first protrusions 10a are provided on the upper surface of the central movable part 10B, and the first protrusions 10a protrude upward from the upper surface of the central movable part 10B (see FIGS. 7 and 8).

[0055] As shown in FIGS. 5 and 6, a plurality of first recesses 12a are formed on the lower surface of the annular portion 12C of the first partition portion 12, and the first recesses 12a are recessed upward from the lower surface of the annular portion 12C.

[0056] The first protrusions 10a and the first recesses 12a face each other in the vertical direction, and the upper ends (tips) of the first protrusions 10a are individually inserted into the first recesses 12a. In other words, the first protrusions 10a abut against the annular portion 12C of the first partition wall portion 12.

[0057] As shown in FIG. 2, a plurality of second protrusions 10b are provided on the lower surface of the central movable portion 10B, and the second protrusions 10b protrude downward from the lower surface of the central movable portion 10B.

[0058] As shown in FIGS. 3 and 4, a plurality of second recesses 13a are formed on the upper surface of the disk portion 13E of the second partition portion 13, and the second recesses 13a are recessed downward from the upper surface of the disk portion 13E.

[0059] The second protrusions 10b and the second recesses 13a face each other in the vertical direction, and the lower ends (tips) of the second protrusions 10b are individually inserted into the second recesses 13a. In other words, the second protrusions 10b abut against the disk portion 13E of the second partition wall portion 13.

[0060] The central movable part 10B of the movable part 10 is held in a neutral position when the first protrusion 10a and the second protrusion 10b are not deformed, and a gap 15 of a certain size is formed between the first partition part 12 and the central movable part 10B, and a gap 16 of a certain size is formed between the second partition part 13 and the central movable part 10B.

[0061] As shown in FIG. 2, the partition member 7 is provided with a relief valve 17, which has the function of connecting the pressure-receiving chamber 8 to the equilibrium chamber 9 when negative pressure occurs in the pressure-receiving chamber 8.

[0062] The relief valve 17 is configured to include a valve hole portion 10C provided in the center of the central movable portion 10B, and a valve protrusion portion 13H provided on the disc portion 13E of the second partition portion 13 so as to be inserted into the valve hole portion 10C.

[0063] Valve hole 10C penetrates central movable part 10B in the vertical direction, and the inner peripheral surface of valve hole 10C is formed as first conical surface 10c whose inner diameter increases from first partition wall 12 toward second partition wall 13. In other words, valve hole 10C is formed so that the diameter of the opening at the lower end is larger than the diameter of the opening at the upper end.

[0064] The multiple first protrusions 10a and the multiple second protrusions 10b are arranged concentrically with the central axis S of the valve hole portion 10C, and are arranged around the central axis S along the circumferential direction of the central movable portion 10B.

[0065] The valve protrusion 13H protrudes upward from the disk portion 13E of the second partition portion 13, and the outer surface of the valve protrusion 13H is formed into a second conical surface 13b similar in shape to the first conical surface 10c of the valve hole portion 10C.

[0066] In the neutral position of the central movable part 10B, the first conical surface 10c and the second conical surface 13b are in close contact with each other, and no gap is formed between the first conical surface 10c and the second conical surface 13b.

[0067] In other words, when the central movable part 10B is positioned in the neutral position, the pressure-receiving chamber 8 and the equilibrium chamber 9 are not in communication with each other via the relief valve 17, and no fluid flows between the pressure-receiving chamber 8 and the equilibrium chamber 9 through the gap between the valve hole part 10C and the valve protrusion part 13H.

[0068] On the other hand, when negative pressure is generated in the pressure-receiving chamber 8, the central movable part 10B moves from the neutral position toward the first partition wall part 12, the gap 15 between the first partition wall part 12 and the central movable part 10B becomes smaller, and the first protrusion part 10a is deformed. In other words, the first protrusion part 10a is crushed and compressed in the vertical direction.

[0069] In this state, the central movable part 10B moves upward away from the second partition wall part 13, increasing the gap 16 between the second partition wall part 13 and the central movable part 10B, and forming a gap between the valve protrusion 13H and the valve hole 10C. This allows fluid to flow between the pressure-receiving chamber 8 and the equilibrium chamber 9 through the gap between the valve hole 10C and the valve protrusion 13H.

[0070] When the pressure in the pressure-receiving chamber 8 increases, the central movable part 10B moves toward the second partition wall 13, the gap 16 between the second partition wall 13 and the central movable part 10B becomes smaller, and the second protrusion 10b is deformed. In other words, the second protrusion 10b is crushed and compressed in the vertical direction.

[0071] In this state, the central movable part 10B moves downward away from the first partition part 12, increasing the gap 15 between the first partition part 12 and the central movable part 10B, and the valve protrusion 13H and the valve hole part 10C come into close contact with each other, so that no gap is formed between the valve protrusion 13H and the valve hole part 10C.

[0072] As a result, fluid does not flow between the pressure-receiving chamber 8 and the equilibrium chamber 9 through the gap between the valve hole 10C and the valve projection 13H.

[0073] When a large vibration (impact load) with an amplitude larger than that of a shake vibration is input to the engine mount 1, a compressive force is applied to the vibration-damping rubber 2 that constitutes the fluid chamber 6, pressurizing the pressure-receiving chamber 8 and temporarily clogging the orifice passage 14.

[0074] Then, as a reaction, a force is applied to the vibration-damping rubber 2 in the tensile direction opposite to the compressive direction, reducing the pressure in the pressure-receiving chamber 8, creating an excessively negative pressure inside the pressure-receiving chamber 8 that falls below the saturated vapor pressure of the enclosed fluid, generating a large number of bubbles.

[0075] After that, a compressive force is again applied to the vibration-isolating rubber 2, and as the pressure in the pressure-receiving chamber 8 increases, the pressure exceeds the saturated vapor pressure, causing the bubbles to collapse. This phenomenon of the generation and collapse of bubbles is called cavitation.

[0076] When the bubbles generated by the cavitation phenomenon collapse, the resulting impact noise is transmitted from the engine mount 1 to the vehicle body, which may be perceived by passengers as an unpleasant noise.

[0077] Bubbles are thus generated by the cavitation phenomenon when the pressure inside the pressure-receiving chamber 8 is in a negative pressure state, that is, a reduced pressure state.

[0078] In the engine mount 1 of this embodiment, when the pressure inside the pressure-receiving chamber 8 is reduced, the central movable portion 10B moves from the neutral position toward the first partition wall portion 12. At this time, the first protrusion 10a is compressed, allowing the central movable portion 10B to move toward the first partition wall portion 12.

[0079] Furthermore, when the central movable portion 10B moves from the neutral position toward the first partition portion 12, a gap is formed between the valve protrusion 13H and the valve hole portion 10C, and the pressure-receiving chamber 8 and the equilibrium chamber 9 are connected through the gap between the valve protrusion 13H and the valve hole portion 10C.

[0080] Therefore, even if the orifice passage 14 becomes clogged, the fluid will flow from the equilibrium chamber 9 to the pressure-receiving chamber 8 through the gap between the valve protrusion 13H and the valve hole 10C without passing through the orifice passage 14, and the pressure drop in the pressure-receiving chamber 8 will be quickly resolved.

[0081] Therefore, even if the orifice passage 14 becomes clogged when the pressure inside the pressure-receiving chamber 8 is reduced due to the input of large vibrations, the occurrence of cavitation is prevented.

[0082] On the other hand, when pressure is applied inside the pressure-receiving chamber 8, the central movable part 10B moves from the first partition wall part 12 side to the second partition wall part 13 side. At this time, the second protrusion part 10b is compressed, allowing the central movable part 10B to move toward the second partition wall part 13 side.

[0083] When the central movable portion 10B moves toward the second partition wall portion 13, the valve projection 13H comes into close contact with the valve hole 10C, eliminating any gap between the valve projection 13H and the valve hole 10C.

[0084] As a result, communication between the pressure-receiving chamber 8 and the equilibrium chamber 9 is blocked, and fluid flows from the pressure-receiving chamber 8 to the equilibrium chamber 9 via the orifice passage 14. This maintains the liquid column resonance effect of the orifice passage 14, and effectively damps vibrations even when large vibrations are input.

[0085] As described above, the engine mount 1 of this embodiment comprises a partition member 7 that divides the fluid chamber 6 containing a fluid into a pressure-receiving chamber 8 and an equilibrium chamber 9, and has a first partition wall portion 12 arranged on the pressure-receiving chamber 8 side and a second partition wall portion 13 arranged on the equilibrium chamber 9 side, and an orifice passage 14 provided in the partition member 7 that connects the pressure-receiving chamber 8 and the equilibrium chamber 9.

[0086] The engine mount 1 also includes a movable portion 10 made of an elastic member arranged between the first partition portion 12 and the second partition portion 13, which absorbs internal pressure fluctuations in the pressure-receiving chamber 8 by deflecting the central movable portion 10B, which is formed to be thinner than its outer periphery (annular portion 10A), and a relief valve 17 that connects the pressure-receiving chamber 8 to the equilibrium chamber 9 when negative pressure occurs in the pressure-receiving chamber 8.

[0087] The central movable part 10B has a plurality of first protrusions 10a that abut against the first partition part 12 and a plurality of second protrusions 10b that abut against the second partition part 13, and is held in a neutral position when the first protrusions 10a and the second protrusions 10b are not deformed.

[0088] The relief valve 17 includes a valve hole 10C provided in the central movable portion 10B, and a valve projection 13H provided in the second partition wall portion 13 and inserted into the valve hole 10C.

[0089] When the central movable part 10B is held in the neutral position, no gap is formed between the valve protrusion 13H and the valve hole 10C. On the other hand, when negative pressure is generated in the pressure-receiving chamber 8, the central movable part 10B moves from the neutral position toward the first partition part 12, forming a gap between the valve protrusion 13H and the valve hole 10C, thereby connecting the pressure-receiving chamber 8 to the equilibrium chamber 9 through the relief valve 17.

[0090] As a result, when the central movable part 10B bends and collides with the first partition part 12 or the second partition part 13, the first protrusion 10a and the second protrusion 10b are elastically deformed, so that the first protrusion 10a and the second protrusion 10b can absorb the impact and suppress the impact noise.

[0091] Furthermore, when minute amplitude vibrations are input to the pressure receiving chamber 8, the central movable portion 10B can be deflected to absorb the internal pressure fluctuations in the pressure receiving chamber 8, thereby absorbing the minute amplitude vibrations.

[0092] In addition, when large amplitude vibrations are input, the central movable part 10B moves from the neutral position toward the second partition part 13, and the communication between the pressure receiving chamber 8 and the equilibrium chamber 9 is blocked by the relief valve 17, while the pressure receiving chamber 8 and the equilibrium chamber 9 are connected by the orifice passage 14, thereby damping the large amplitude vibrations.

[0093] Furthermore, when negative pressure occurs in the pressure-receiving chamber 8 due to the input of an impact load, the gap in the relief valve 17 connects the pressure-receiving chamber 8 to the equilibrium chamber 9, allowing fluid to flow from the equilibrium chamber 9 to the pressure-receiving chamber 8 through the relief valve 17, thereby suppressing the generation of abnormal noise due to cavitation.

[0094] Furthermore, the engine mount 1 of this embodiment can suppress cavitation using a relief valve 17 with a simple configuration, rather than using a compression coil spring as in the conventional case, so the structure of the engine mount 1 can be simplified.

[0095] In this way, the engine mount 1 of this embodiment can suppress, with a simple configuration, the impact noise generated when the movable part 10 made of an elastic body collides with the first partition part 12 and the second partition part 13, and the abnormal noise generated by cavitation.

[0096] Furthermore, according to the engine mount 1 of this embodiment, the inner surface of the valve hole portion 10C is formed into a first conical surface 10c whose inner diameter increases as it moves from the first partition portion 12 toward the second partition portion 13.

[0097] The outer peripheral surface of the valve protrusion 13H is formed into a second conical surface 13b similar in shape to the first conical surface 10c, and in the neutral position, no gap is formed between the first conical surface 10c and the second conical surface 13b.

[0098] This allows the first conical surface 10c and the second conical surface 13b to position the valve hole 10C and the valve protrusion 13H, and reliably eliminates any gap between the valve hole 10C and the valve protrusion 13H.

[0099] Furthermore, according to the engine mount 1 of this embodiment, the valve hole portion 10C is formed in the center of the central movable portion 10B, and the multiple first protrusions 10a and the multiple second protrusions 10b are arranged concentrically with the central axis S of the valve hole portion 10C.

[0100] This allows the pressure of the fluid acting on the central movable portion 10B to be evenly supported by the multiple first protrusions 10a and the multiple second protrusions 10b, preventing the valve hole 10C from deforming unevenly in the circumferential direction.

[0101] Furthermore, according to the engine mount 1 of this embodiment, the first partition portion 12 has a plurality of first recesses 12a into which the upper ends of the plurality of first protrusions 10a are individually inserted, and the second partition portion 13 has a plurality of second recesses 13a into which the lower ends of the plurality of second protrusions 10b are individually inserted.

[0102] As a result, the first recess 12a and the second recess 13a can prevent the central movable part 10B from being misaligned with the first partition part 12 and the second partition part 13, allowing the central movable part 10B to be smoothly elastically deformed.

[0103] While an embodiment of the present invention has been disclosed, it will be apparent to those skilled in the art that modifications may be made without departing from the scope of the invention, and all such modifications and equivalents are intended to be encompassed by the following claims. [Explanation of symbols]

[0104] 1 Engine mount (fluid-filled vibration isolation device) 7 Partition material 8. Pressure chamber 9 Equilibrium chamber 10 Moving parts 10a First protrusion 10B Central movable part 10b Second protrusion 10C Valve hole 10c First conical surface 12 first partition wall 12a First recess 13 Second partition 13a Second recess 13b Second conical surface 13H Valve protrusion 14 Orifice passage 17 Relief valve S Central axis of valve hole

Claims

1. a partition member that divides a fluid chamber in which a fluid is sealed into a pressure-receiving chamber and an equilibrium chamber, and that has a first partition wall portion disposed on the pressure-receiving chamber side and a second partition wall portion disposed on the equilibrium chamber side; an orifice passage provided in the partition member and communicating the pressure-receiving chamber with the equilibrium chamber; a movable portion made of an elastic member disposed between the first partition wall and the second partition wall, the movable portion flexing a central movable portion formed to be thinner than an outer periphery of the central movable portion to absorb internal pressure fluctuations in the pressure-receiving chamber; a relief valve that connects the pressure-receiving chamber to the equilibrium chamber when negative pressure occurs in the pressure-receiving chamber, the central movable portion has a plurality of first protrusions that contact the first partition wall portion and a plurality of second protrusions that contact the second partition wall portion, and is held in a neutral position when the first protrusions and the second protrusions are not deformed; the relief valve includes a valve hole provided in the central movable portion and a valve protrusion provided in the second partition wall portion and inserted into the valve hole, a fluid-filled vibration damping device characterized in that when the central movable part is held in the neutral position, no gap is formed between the valve protrusion and the valve hole, while when negative pressure is generated in the pressure-receiving chamber, the central movable part moves from the neutral position toward the first partition part, forming a gap between the valve protrusion and the valve hole, thereby connecting the pressure-receiving chamber to the equilibrium chamber through the relief valve.

2. an inner circumferential surface of the valve hole is formed into a first conical surface whose inner diameter increases from the first partition wall toward the second partition wall, an outer peripheral surface of the valve projection is formed into a second conical surface similar in shape to the first conical surface; 2. The fluid-filled vibration damping device according to claim 1, wherein, in the neutral position, the first conical surface and the second conical surface are in close contact with each other, and no gap is formed between the first conical surface and the second conical surface.

3. the valve hole is formed in the center of the central movable part, 3. The fluid-filled vibration damping device according to claim 1, wherein the plurality of first protrusions and the plurality of second protrusions are arranged on a circle concentric with the central axis of the valve hole.

4. the first partition wall has a plurality of first recesses into which the tips of the plurality of first protrusions are individually inserted, 3. The fluid-filled vibration-damping device according to claim 1, wherein the second partition wall has a plurality of second recesses into which the tips of the plurality of second protrusions are individually inserted.

5. the first partition wall has a plurality of first recesses into which the tips of the plurality of first protrusions are individually inserted, 4. The fluid-filled vibration-damping device according to claim 3, wherein the second partition wall has a plurality of second recesses into which the tips of the plurality of second protrusions are individually inserted.

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