Liquid-filled vibration isolation device

Abstract

To provide a liquid sealed type vibration control device which can inhibit abnormal noise occurring when a movable plate and gratings contact with each other.SOLUTION: Since a plurality of first protrusions 25 protrude from a plurality of first gratings 23b of a first partition plate 23 toward a movable plate 30, deformation or displacement of the movable plate 30 toward the first partition plate 23 can be restricted by the first protrusions 25. Further, compared to a case where protrusions for restricting the deformation or displacement are provided on the movable plate 30, the weight of the movable plate 30 can be reduced by providing the first protrusions 25 on the first grating 23b. Consequently, striking sound generating energy caused by contact between the first gratings 23b and the movable plate 30 can be reduced, and abnormal noise occurring due to the striking sound can be prevented.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a liquid-filled vibration isolator, and more particularly to a liquid-filled vibration isolator capable of suppressing abnormal noise when a movable plate contacts a lattice.

Background Art

[0002] As a vibration isolator for supporting a vibration source such as an engine on a vehicle body (support side), for example, a liquid-filled vibration isolator disclosed in Patent Document 1 is known. The liquid-filled vibration isolator disclosed in Patent Document 1 has a liquid chamber formed therein partitioned into a first liquid chamber and a second liquid chamber by a partition body. The partition body includes a first partition plate facing the first liquid chamber, a second partition plate facing the second liquid chamber, and a movable plate disposed between the first partition plate and the second partition plate and composed of a disk-shaped elastic body.

[0003] A plurality of through-holes penetrating in the plate thickness direction are formed side by side in the circumferential direction on the first partition plate and the second partition plate, and a lattice is formed between the plurality of through-holes. The liquid pressures in the first liquid chamber and the second liquid chamber are applied to the movable plate through the through-holes, and the vibration energy input to the liquid-filled vibration isolator is consumed by the deformation or displacement of the movable plate. Further, the deformation or displacement of the movable plate is restricted by bringing projections protruding from the movable plate into contact with the lattice of the first partition plate or the second partition plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, since the disc-shaped movable plate may rotate circumferentially when assembling the movable plate to the first and second partition plates or during use, it is necessary to form a ring-shaped projection for contact with the grid. In this way, since projections are also provided on the part that does not contact the grid but faces the through hole, the weight of the movable plate increases. As a result, the energy required to generate a tapping sound due to contact between the movable plate and the grid increases, which may worsen the noise reduction performance.

[0006] The present invention was made to solve the above-mentioned problems, and aims to provide a liquid-filled vibration isolation device that can suppress abnormal noise when the movable plate and the grid come into contact. [Means for solving the problem]

[0007] To achieve this objective, the liquid-filled vibration isolation device of the present invention comprises a first member and a cylindrical second member, an elastic vibration isolation base connecting the first member and the second member, an elastic diaphragm attached to the second member and forming a liquid chamber between it and the vibration isolation base in which liquid is sealed, a partition body dividing the liquid chamber into a first liquid chamber and a second liquid chamber, and an orifice connecting the first liquid chamber and the second liquid chamber, wherein the partition body comprises a first partition plate facing the first liquid chamber having a plurality of first through holes penetrating in the thickness direction and arranged in the circumferential direction, and a plurality of first grids formed between the plurality of first through holes, a second partition plate facing the second liquid chamber, and an elastic movable plate positioned between the first partition plate and the second partition plate so as to be opposite to the plurality of first through holes and the first grids, wherein a plurality of first protrusions project from the plurality of first grids toward the movable plate. [Effects of the Invention]

[0008] According to the liquid-filled vibration isolation device described in claim 1, since multiple first protrusions protrude from multiple first grids of the first partition plate toward the movable plate, the deformation or displacement of the movable plate toward the first partition plate can be restricted by the first protrusions. Furthermore, compared to the case where protrusions for restricting such deformation or displacement are provided on the movable plate, the movable plate can be made lighter by providing the first protrusions on the first grid. As a result, the energy generated by the impact sound caused by the contact between the first grid and the movable plate can be reduced, and abnormal noises based on that impact sound can be suppressed.

[0009] The The partition plate comprises a plurality of second through-holes that penetrate the plate thickness direction and are arranged circumferentially in the portion facing the movable plate, and a plurality of second grids formed between the plurality of second through-holes. Since a plurality of second protrusions protrude from this second grid toward the movable plate, the deformation or displacement of the movable plate toward the second partition plate can be restricted by the second protrusions. Furthermore, compared to the case in which protrusions for restricting such deformation or displacement are provided on the movable plate, the movable plate can be made lighter by providing the second protrusions on the second grid. Therefore, the energy generated by the impact sound caused by the contact between the first partition plate and the second partition plate and the movable plate can be reduced, and abnormal noises based on these impact sounds can be suppressed.

[0010] Claim 2 According to the liquid-filled vibration isolation device described, 1 In addition to the effects of the liquid-filled vibration isolation device described above, the following effects are also achieved. The multiple first grids and multiple second grids are arranged offset from each other in the circumferential direction. This prevents the strain that occurs when the first protrusions protruding from the first grids and the second protrusions protruding from the second grids contact the movable plate from concentrating on a part of the movable plate in the circumferential direction. As a result, the durability of the movable plate can be improved.

[0011] Claim 3 According to the liquid-filled vibration isolation device described, claim 1 or 2In addition to the effects of the liquid-filled vibration isolation device described above, the following effects are achieved: Multiple first protrusions have different heights. As a result, when the movable plate deforms or displaces toward the first partition plate, the number of first protrusions in contact with the movable plate gradually increases, and its deformation or displacement is restricted. This suppresses the noise generated when the first protrusions and the movable plate come into contact, compared to the case where all first protrusions contact the movable plate at approximately the same time.

[0012] Claim 4 According to the liquid-filled vibration isolation device described, claim 1 or 2 In addition to the effects of the liquid-filled vibration isolation device described above, the following effects are also achieved. Some of the multiple first protrusions have radially offset positions where they protrude from the first grid. As a result, depending on how the movable plate deforms or displaces toward the first partition plate, the number of first protrusions that come into contact with the movable plate gradually increases, and this deformation or displacement may be restricted. In this case, compared to the case where all of the first protrusions come into contact with the movable plate at approximately the same time, the noise generated when the first protrusions come into contact with the movable plate can be suppressed.

[0013] Claim 5 According to the liquid-filled vibration isolation device described, claim 1 or 2 In addition to the effects of the liquid-filled vibration isolation device described above, the following effects are achieved: The first partition plate has an annular portion that extends radially outward and inward from the first grid and is continuous in the circumferential direction. The movable plate has an annular projection that protrudes so as to be able to contact this annular portion. The first projection is lower than this annular projection. Therefore, even when the annular projection is in contact with the annular portion, the movable plate can be deflected toward the first projection, and damping performance can be ensured by this deflection.

[0014] Claim 6 According to the liquid-filled vibration isolation device described, claim 1 or 2In addition to the effects achieved by the liquid-filled vibration isolator described in [reference], the following effects are achieved. The movable plate formed in a disk shape or an annular disk shape floats in the liquid rotatably in the circumferential direction of the movable plate with respect to the first partition plate and the second partition plate. In response to the rotation of this movable plate, the contact position of the first protrusion with respect to the movable plate changes. Therefore, since it is possible to suppress the concentration of the strain at the time of contact with the first protrusion in a part of the circumferential direction of the movable plate, the durability of the movable plate can be improved.

Brief Description of the Drawings

[0015] [Figure 1] It is a cross-sectional view of the liquid-filled vibration isolator in the first embodiment. [Figure 2] It is a plan view of the partition body. [Figure 3] It is a cross-sectional view of the partition body on the III-III line in FIG. 2. [Figure 4] It is a cross-sectional view of the partition body in the second embodiment. [Figure 5] It is a plan view of the partition body in the third embodiment.

Modes for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of the liquid-filled vibration isolator 10 in the first embodiment. Note that FIG. 1 shows a no-load state in which no vibration (load) is input to the liquid-filled vibration isolator 10. Unless otherwise specified, each part of the liquid-filled vibration isolator 10 will be described in the no-load state. Also, in the following description, the upper side on the paper surface of FIG. 1 will be described as the upper side of the liquid-filled vibration isolator 10 and the like, but the up and down of this liquid-filled vibration isolator 10 does not necessarily coincide with the up and down of the vehicle to which the liquid-filled vibration isolator 10 is attached.

[0017] The liquid-filled vibration isolator 10 is an engine mount that elastically supports the engine of an automobile. The liquid-filled vibration isolator 10 mainly includes a first member 11 attached to the engine side which is the vibration source, a cylindrical second member 12 attached to the vehicle body on the support side, and a vibration isolation base 13 composed of an elastic body that connects the first member 11 and the second member 12. Note that the cross-sectional view of the liquid-filled vibration isolator 10 in FIG. 1 is an axial cross-sectional view including the axial center C of the cylindrical second member 12. The direction of the axial center C (axial direction) is the vertical direction of the liquid-filled vibration isolator 10.

[0018] The first member 11 is a boss fitting arranged on the axial center C so as to be located above the second member 12, and is formed of a metal such as steel or an aluminum alloy. Bolt holes are formed on the upper end surface of the first member 11. The first member 11 is attached to the engine side via bolts attached to the bolt holes.

[0019] The second member 12 is a cylindrical member centered on the axial center C, and is mainly formed of a metal such as steel. The second member 12 includes a large-diameter portion 12a on the upper end side, a reduced-diameter portion 12b that continues to the lower end of the large-diameter portion 12a and whose inner and outer diameters gradually decrease downward, and a small-diameter portion 12c that continues to the lower end of the reduced-diameter portion 12b and has inner and outer diameters smaller than those of the large-diameter portion 12a. For example, the second member 12 is attached to the vehicle body side by being inserted into a cylindrical bracket provided on the vehicle body side.

[0020] The vibration isolation base 13 is a member made of an elastic body such as rubber or thermoplastic elastomer formed in a substantially umbrella shape. The vibration isolation base 13 is vulcanization-bonded to the lower part of the first member 11 and the inner peripheral surfaces of the large-diameter portion 12a and the reduced-diameter portion 12b, respectively, to connect them. A rubber film-shaped film portion 14 that covers the inner peripheral surface of the small-diameter portion 12c continues to the lower end portion of the vibration isolation base 13. This film portion 14 is a part of the second member 12.

[0021] A diaphragm 15 is attached to the second member 12 via a mounting portion 16 so as to close the lower end opening of the small-diameter portion 12c. The diaphragm 15 is a membrane made of an elastic material such as rubber. The mounting portion 16 is an annular metal member made of steel or similar material. The outer circumference of the diaphragm 15 is vulcanized and bonded to the inner circumference of the mounting portion 16 over its entire circumference.

[0022] A liquid chamber is formed by a sealed space partitioned by the vibration-isolating base 13, the second member 12, and the diaphragm 15. An antifreeze liquid (not shown), such as ethylene glycol, is sealed in the liquid chamber. The liquid chamber is divided by a partition 20 into a first liquid chamber 17, in which the vibration-isolating base 13 forms part of the chamber wall, and a second liquid chamber 18, in which the diaphragm 15 forms part of the chamber wall.

[0023] To attach the diaphragm 15 and partition 20 to the second member 12, first, the partition 20 is inserted into the small-diameter portion 12c of the second member 12 until it hits the step 13a of the vibration-damping base 13, which protrudes radially inward from the upper end of the membrane portion 14. Next, the mounting portion 16, into which the diaphragm 15 is integrated, is inserted into the small-diameter portion 12c. Then, the small-diameter portion 12c (second member 12) is reduced in diameter by drawing, and the outer circumference of the partition 20 and mounting portion 16 is held by the membrane portion 14. In this way, the diaphragm 15 and partition 20 are attached to the second member 12.

[0024] The partition body 20 will be explained with reference to Figures 1, 2 and 3. Figure 2 is a plan view of the partition body 20. A cross-section of the partition body 20 along line II in Figure 2 is shown in Figure 1. In Figure 2, multiple first protrusions 25 are shown by dashed lines. Figure 3 is a cross-sectional view of the partition body 20 along line III-III in Figure 2. In Figure 3, the boundary line between the first grid 23b and the first protrusion 25, and the boundary line between the second grid 26b and the second protrusion 28 are shown by dashed lines.

[0025] As shown in Figures 1 and 2, the partition body 20 comprises a cylindrical member 21 held inside the membrane portion 14, flat first partition plate 23 and second partition plate 26 that partition the inner circumference of the cylindrical member 21 vertically, and a movable plate 30 positioned between the first partition plate 23 and the second partition plate 26. The first partition plate 23 facing the first liquid chamber 17 and the second partition plate 26 facing the second liquid chamber 18 are joined together by overlapping them vertically and welding, bonding, or press-fitting.

[0026] The cylindrical member 21 is a cylindrical part made of metal or synthetic resin. The outer surface of the cylindrical member 21 is pressed against the small diameter portion 12c of the second member 12 via the membrane portion 14 along its entire circumference. An outer circumferential groove 22 with a length of approximately two turns is formed on the outer surface of the cylindrical member 21. The first orifice 19 is formed between this outer circumferential groove 22 and the membrane portion 14.

[0027] One end of the outer circumferential groove 22 opens to the inner circumferential surface of the cylindrical member 21 above the first partition plate 23 or to the upper end of the cylindrical member 21, thereby connecting the first orifice 19 to the first liquid chamber 17. The other end of the outer circumferential groove 22 opens to the inner circumferential surface of the cylindrical member 21 below the second partition plate 26 or to the lower end of the cylindrical member 21, thereby connecting the first orifice 19 to the second liquid chamber 18.

[0028] Thus, the first orifice 19 is a flow path that connects the first liquid chamber 17 and the second liquid chamber 18. The first orifice 19 is configured such that, for example, to dampen shaking vibrations during vehicle operation, the damping coefficient becomes large in the frequency band corresponding to the shaking vibrations (for example, around 5 to 15 Hz) when large-amplitude shaking vibrations are input. The flow path cross-sectional area, length, and cross-sectional circumference of the first orifice 19 are set accordingly.

[0029] The first partition plate 23 is made of metal or synthetic resin and is formed in a disc shape perpendicular to the axis C. A cylindrical base portion 23a protrudes downward (towards the second partition plate 26) from the radial center of the first partition plate 23, with the axis C as the center.

[0030] Multiple first through holes 24 are formed in the first partition plate 23 radially outward from the base portion 23a, extending in the thickness direction (vertical direction). The multiple first through holes 24 are arranged in a circumferential direction. Multiple first grids 23b are formed between these multiple first through holes 24. The first grids 23b extend radially with a substantially constant width around the axis C.

[0031] Multiple first projections 25 protrude downward from the radial center of each of the multiple first lattices 23b. One first projection 25 is provided for each first lattice 23b. The first projections 25 are formed in the shape of a frustocone.

[0032] The first partition plate 23 comprises an inner annular portion 23c that extends radially inward from the first grid 23b and is continuous in the circumferential direction, and an outer annular portion 23d that extends radially outward from the first grid 23b and is continuous in the circumferential direction. The inner annular portion 23c is the part that connects the first grid 23b and the base portion 23a in the radial direction. The outer annular portion 23d extends to the inner circumferential surface of the cylindrical member 21.

[0033] A cylindrical portion 23e extends upward from the outer annular portion 23d, and a flange 23f extends radially outward from the upper end edge of the cylindrical portion 23e. The first partition plate 23 is attached to the cylindrical member 21 by fitting the cylindrical portion 23e to the inner circumference of the cylindrical member 21 until the flange 23f contacts the upper end of the cylindrical member 21. The flange 23f that has contacted the upper end of the cylindrical member 21 contacts the step 13a of the vibration-damping base 13. In addition, a portion of the cylindrical portion 23e and the flange 23f is omitted in the circumferential direction so as not to block the opening of the outer peripheral groove 22 on the first liquid chamber 17 side.

[0034] The second partition plate 26 is integrally molded with the cylindrical member 21 and is formed in a disc shape perpendicular to the axis C. The outer edge of the second partition plate 26 is connected to the inner surface of the cylindrical member 21 along its entire circumference, forming a storage space 29 between the first partition plate 23 attached to the cylindrical member 21 and the second partition plate 26.

[0035] A cylindrical base portion 26a, centered on axis C, protrudes upward (towards the first partition plate 23) from the radial center of the second partition plate 26, opposite the base portion 23a. The ends of this base portion 26a and the base portion 23a of the first partition plate 23 are joined together by welding or other means. The storage space 29 is provided around these base portions 23a and 26a and is formed in an annular shape.

[0036] Multiple second through holes 27 are formed in the thickness direction of the second partition plate 26, radially outward from the base portion 26a. The multiple second through holes 27 are arranged in a circumferential direction. Multiple second grids 26b are formed between these multiple second through holes 27. The second grids 26b extend radially with a substantially constant width around the axis C.

[0037] Multiple second projections 28 protrude upward from the radial center of each of the multiple second lattices 26b. One second projection 28 is provided for each second lattice 26b. The second projections 28 are formed in a frustoconical shape.

[0038] As shown in Figures 1 and 3, the second through-hole 27, the second grid 26b, and the second projection 28 are set in shape, position, and dimensions (height H1, etc.) symmetrically (mirror-like) to the first through-hole 24, the first grid 23b, and the first projection 25 of the first partition plate 23, respectively. Therefore, the bottom view of the partition body 20 is substantially the same as the plan view of the partition body 20 shown in Figure 2.

[0039] As shown in Figure 1, the second partition plate 26 comprises an inner annular portion 26c that extends radially inward from the second grid 26b and is continuous in the circumferential direction, and an outer annular portion 26d that extends radially outward from the second grid 26b and is continuous in the circumferential direction. The inner annular portion 26c is the part that connects the second grid 26b and the base portion 26a in the radial direction. The outer annular portion 26d extends to the inner circumferential surface of the cylindrical member 21.

[0040] The movable plate 30 is a component made of an elastic material such as rubber or thermoplastic elastomer, and is formed in the shape of an annular plate with its axis C. The movable plate 30 is placed in the storage space 29 between the first partition plate 23 and the second partition plate 26, and surrounds the base portions 23a and 26a.

[0041] Through the first through-holes 24 and 27 formed in the first partition plate 23 and the second partition plate 26, respectively, the hydraulic pressure from the first liquid chamber 17 and the second liquid chamber 18 is applied to the movable plate 30 in the containment space 29. As the movable plate 30 deforms or displaces due to this hydraulic pressure, the vibration energy input to the liquid-filled vibration isolation device 10 is consumed, and the vibration can be dampened by the liquid-filled vibration isolation device 10.

[0042] The movable plate 30 has portions facing the multiple first through holes 24, the first grid 23b, the second through hole 27, and the second grid 26b formed in a flat shape. Furthermore, the movable plate 30 includes an annular projection 31 projecting toward the inner annular portion 23c, an annular projection 32 projecting toward the outer annular portion 23d, an annular projection 33 projecting toward the inner annular portion 26c, and an annular projection 34 projecting toward the outer annular portion 26d.

[0043] The annular projections 31 to 34 are all continuous annular portions extending around the entire circumference, and two of each are arranged on concentric circles centered on axis C. Furthermore, annular projections 31 and 33 are arranged alternately on both the upper and lower surfaces. Similarly, annular projections 32 and 34 are arranged alternately on both the upper and lower surfaces. This reduces the difference in rigidity between the thick and thin parts of the movable plate 30 compared to when each projection is arranged in the same position on both the upper and lower surfaces. As a result, it is possible to suppress the likelihood of cracks starting from the thin parts of the movable plate 30, thereby improving the durability of the movable plate 30.

[0044] Furthermore, the heights H2 of the annular protrusions 31 to 34 are all the same, and the vertical dimension of the storage space 29 is greater than the overall thickness of the movable plate 30 (the vertical distance between the tips of the annular protrusions 31 to 34 on both the upper and lower sides). Moreover, the inner diameter of the storage space 29 (the outer diameter of the base portions 23a and 26a) is smaller than the inner diameter of the movable plate 30, and the outer diameter of the storage space 29 (the inner diameter of the cylindrical member 21) is larger than the outer diameter of the movable plate 30. Therefore, when the movable plate 30 is located in the center of the storage space 29 (not in contact with any of the walls of the storage space 29), a second orifice is formed connecting the first liquid chamber 17 and the second liquid chamber 18 by the gap between each wall of the storage space 29 and the movable plate 30, the first through hole 24, and the second through hole 27.

[0045] This second orifice is designed to reduce idle vibrations, for example, when the vehicle is idling (stopped). The flow path cross-sectional area, length, and perimeter of the second orifice are set so that the damping coefficient increases in the frequency band corresponding to the idle vibration (for example, around 15-50 Hz) when small amplitude idle vibrations are input.

[0046] When the movable plate 30 is displaced vertically due to the application of hydraulic pressure to the movable plate 30 through the first through-hole 24 and the second through-hole 27, the second orifice may be blocked. Specifically, the second orifice is blocked when the annular projections 31 and 32 are pressed against the inner annular portion 23c and the outer annular portion 23d of the first partition plate 23, respectively, over their entire circumference. Also, the second orifice is blocked when the annular projections 33 and 34 are pressed against the inner annular portion 26c and the outer annular portion 26d of the second partition plate 26, respectively, over their entire circumference. When the second orifice is blocked, the damping characteristics of the first orifice 19 are mainly exerted.

[0047] Even in this blocked state, the movable plate 30 between the annular protrusions 31 and 32 and between the annular protrusions 33 and 34 deforms (displaces) in the vertical direction due to the application of hydraulic pressure through the first through hole 24 and the second through hole 27. When this deformed movable plate 30 comes into contact with the first protrusion 25 of the first grid 23b or the second protrusion 28 of the second grid 26b, the deformation of the movable plate 30 is restricted.

[0048] Compared to the case where an annular projection is provided on the movable plate 30 to restrict its deformation, the movable plate 30 can be made lighter by providing the first projection 25 on the first grid 23b and the second projection 28 on the second grid 26b. As a result, the energy generated by the impact sound caused by the contact between the first partition plate 23 and the second partition plate 26 and the movable plate 30 can be reduced. Therefore, abnormal noises resulting from that impact sound can be suppressed.

[0049] Furthermore, the heights H1 of the first projection 25 and the second projection 28 are lower than the heights H2 of the annular projections 31-34. Therefore, even when the annular projections 31 and 32 are in contact with the inner annular portion 23c and the outer annular portion 23d, the movable plate 30 can be deflected toward the first projection 25, and damping performance can be ensured by this deflection. Similarly, even when the annular projections 33 and 34 are in contact with the inner annular portion 26c and the outer annular portion 26d, the movable plate 30 can be deflected toward the second projection 28, and damping performance can be ensured by this deflection.

[0050] The movable plate 30 floats in the liquid of the containment space 29 without being sandwiched between the first partition plate 23 and the second partition plate 26. Therefore, the movable plate 30 is circumferentially rotatable with respect to the first partition plate 23 and the second partition plate 26. As the movable plate 30 rotates, the contact positions of the first projection 25 and the second projection 28 with respect to the movable plate 30 change. Thus, the strain caused by contact with the first projection 25 and the second projection 28 can be suppressed from concentrating on a part of the circumferential direction of the movable plate 30, thereby improving the durability of the movable plate 30.

[0051] Next, a second embodiment will be described with reference to Figure 4. In the first embodiment, the case was described in which the first grid 23b and the second grid 26b face each other and the heights H1 of the first projection 25 and the second projection 28 are all the same. In contrast, the second embodiment will describe in which the multiple first grids 23b and multiple second grids 26b are offset from each other in the circumferential direction and the heights of the first projections 25, 25a, 25b and the second projections 28a, 28b are different. Note that parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted below.

[0052] Figure 4 is a cross-sectional view of the partition body 40 of the liquid-filled vibration isolation device in the second embodiment. Figure 4 shows a cross-section at the same position as in Figure 3. The first partition plate 41 and the second partition plate 42 of the partition body 40 are configured substantially the same as the first partition plate 23 and the second partition plate 26 in the first embodiment, so only the differences between them will be explained below.

[0053] Multiple first protrusions 25, 25a, and 25b protrude downward from multiple first grids 23b of the first partition plate 41. The height H3 of the first protrusion 25a is greater than the height H1 of the first protrusion 25, and the height H4 of the first protrusion 25b is less than the height H1 of the first protrusion 25.

[0054] As a result, when the movable plate 30 deforms or displaces toward the first partition plate 41, the first protrusions 25a, 25, and 25b come into contact with the movable plate 30 in that order, restricting its deformation or displacement. In this way, the number of first protrusions 25, 25a, and 25b that come into contact with the movable plate 30 gradually increases, which suppresses the noise generated when the first protrusions 25, 25a, and 25b come into contact with the movable plate 30, compared to the case where all of the first protrusions 25 come into contact with the movable plate 30 at approximately the same time, as in the first embodiment.

[0055] Multiple second protrusions 28a and 28b protrude upward from multiple second grids 26b of the second partition plate 42. Although not shown in the figure, a second protrusion 28 (see Figure 3) protrudes upward from the second grid 26b to the right of the second protrusion 28a in Figure 4. The height H3 of the second protrusion 28a is greater than the height H1 of the second protrusion 28, and the height H4 of the second protrusion 28b is less than the height H1 of the second protrusion 28. As a result, when the movable plate 30 deforms or displaces toward the second partition plate 42, the second protrusions 28a, 28, and 28b come into contact with the movable plate 30 in that order. Consequently, similar to the first protrusions 25, 25a, and 25b, abnormal noise when the second protrusions 28, 28a, and 28b come into contact with the movable plate 30 can be suppressed.

[0056] The first protrusions 25, 25a, and 25b are arranged periodically in the circumferential direction (as you move towards the right side of the paper in Figure 4) in the order of heights H3, H1, and H4. The same applies to the second protrusions 28, 28a, and 28b. As a result, it is possible to easily control how the movable plate 30 deforms when it comes into contact with the first protrusions 25, 25a, and 25b, and the second protrusions 28, 28a, and 28b, respectively, and to easily control the characteristics of the movable plate 30 at the time of contact.

[0057] The first grid 23b of the first partition plate 41 and the second grid 26b of the second partition plate 42 are offset from each other in the circumferential direction. This prevents the strain that occurs when the first protrusions 25, 25a, 25b protruding from the first grid 23b and the second protrusions 28, 28a, 28b protruding from the second grid 26b contact the movable plate 30 from concentrating on a part of the circumferential direction of the movable plate 30. As a result, the durability of the movable plate 30 can be improved.

[0058] Furthermore, the second lattice 26b is positioned midway between adjacent first lattices 23b, and the first lattice 23b is positioned midway between adjacent second lattices 26b. This makes it easier to distribute the distortion of the movable plate 30 more circumferentially when it comes into contact with the first protrusions 25, 25a, 25b and the second protrusions 28, 28a, 28b. As a result, the durability of the movable plate 30 can be further improved.

[0059] The alternating first protrusions 25, 25a, 25b and the second protrusions 28, 28a, 28b are periodically arranged in the circumferential direction (towards the right side of the paper in Figure 4) in the order of heights H4, H1, H3. That is, for example, the first protrusion 25, with a height of H1, is positioned between the second protrusion 28b, with a height of H4, and the second protrusion 28a, with a height of H3. This makes it easier to control how the movable plate 30 vibrates up and down between the first protrusions 25, 25a, 25b and the second protrusions 28, 28a, 28b, and to control the deformation of the movable plate 30 that contacts them, and makes it easier to control the characteristics of the movable plate 30 when it makes contact.

[0060] Next, a third embodiment will be described with reference to Figure 5. In the first embodiment, the case in which all first projections 25 are arranged in the radial center of the first grid 23b was described. In contrast, the third embodiment will describe the case in which multiple first projections 25, 51, 52 are arranged offset in the radial direction. Note that parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted below.

[0061] Figure 5 is a plan view of the partition body 50 of the liquid-filled vibration isolation device in the third embodiment. Multiple first protrusions 25, 51, and 52 project from multiple first grids 23b of the first partition plate 23 of the partition body 50 toward the movable plate 30 (see Figure 1). In Figure 5, these multiple first protrusions 25, 51, and 52 are shown by dashed lines.

[0062] The first projection 25 protrudes from the radial center of the first grid 23b. The first projection 51 protrudes from the radial outside of the first grid 23b. The first projection 52 protrudes from the radial inside of the first grid 23b. As a result, depending on how the movable plate 30 deforms or displaces toward the first partition plate 23, the number of first projections 25, 51, and 52 that contact the movable plate 30 gradually increases, and its deformation or displacement may be restricted.

[0063] Specifically, in this embodiment, annular protrusions 31 and 32 (see Figure 1) are provided on the radially inner and outer sides of the movable plate 30. When these protrusions come into contact with the first partition plate 23, the movable plate 30 deforms between the annular protrusions 31 and 32 toward the first protrusions 25, 51, and 52. This deformation increases as the movable plate moves away from the annular protrusions 31 and 32. As a result, compared to the case in the first embodiment where all of the first protrusions 25 come into contact with the movable plate 30 at approximately the same time, the noise generated when the first protrusions 25, 51, and 52 come into contact with the movable plate 30 can be suppressed.

[0064] The first projections 25, 51, and 52 are arranged periodically in a clockwise direction in the circumferential direction, in the order of the radial center, outer side, and inner side. This makes it easier to control how the movable plate 30 deforms when it comes into contact with the first projections 25, 51, and 52, and thus makes it easier to control the characteristics of the movable plate 30 at the time of contact.

[0065] Although the present invention has been described above based on embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention. For example, the first member 11 may be positioned at a location offset radially from the axis C. Also, the axis C of the second member 12 and the axis C of the movable plate 30 may be offset. Cavitation valves may be provided at the positions of the base portions 23a and 26a to move liquid from the second liquid chamber 18 to the first liquid chamber 17 when the first liquid chamber 17 becomes excessively negative pressure.

[0066] Furthermore, the position and length of the first orifice 19 may be changed as appropriate. Another liquid chamber may be formed inside the partition 20, separate from the first liquid chamber 17 and the second liquid chamber 18. The two liquid chambers may be connected by an orifice separate from the first orifice 19.

[0067] Alternatively, a cup-shaped cap fitting may be provided at the lower part of the diaphragm 15 (on the opposite side from the first liquid chamber 17 and the second liquid chamber 18), and an air chamber may be formed by the inner surface of the cap fitting and the diaphragm 15. This air chamber may be made into a sealed space to provide an air spring effect. A through hole may be provided in a part of the cap fitting to open the air chamber to the atmosphere, and a damping effect may be added by the air passing through the through hole.

[0068] In the above embodiment, an engine mount was given as an example of an application target for the liquid-filled vibration damping device 10, but the application target is arbitrary. Other examples of application targets include motor mounts, member mounts, and differential mounts. Furthermore, it is not limited to attaching the first member 11 to the vibration source side such as the engine and attaching the second member 12 to the vibration receiving side such as the vehicle body; the second member 12 may be attached to the vibration source side and the first member 11 may be attached to the vibration receiving side.

[0069] In the above embodiment, a case was described in which the vibration-damping base 13 constitutes a part of the chamber wall of the first liquid chamber 17 and the diaphragm 15 constitutes a part of the chamber wall of the second liquid chamber 18, but the invention is not limited to this. For example, the second liquid chamber 18 may be called the first liquid chamber, and the first liquid chamber 17 may be called the second liquid chamber. In this case, the names of the parts of the partitions 20, 40, and 50 in the above embodiment, namely "first" and "second," are basically reversed.

[0070] Some parts of the above embodiment may be omitted. For example, the cylindrical portion 23e and flange 23f of the first partition plate 23 may be omitted. The membrane portion 14 may be omitted and the partitions 20, 40, 50 and the diaphragm 15 may be attached to the inner circumferential surface of the second member 12. At least one of the annular protrusions 31 to 34 may be omitted. Also, the base portions 23a and 26a may be omitted and the movable plate 30 may be formed in a disc shape.

[0071] Parts of each of the above embodiments may be combined with parts of other embodiments. For example, the positions of the first protrusions 25, 25a, and 25b, which have different heights H1, H3, and H4 in the second embodiment, may be shifted radially, as in the third embodiment. Also, the positions of the multiple second protrusions 28, 28a, and 28b in the first and second embodiments may be shifted radially, as in the first protrusions 25, 51, and 52 in the third embodiment.

[0072] Furthermore, when the heights of multiple first and second protrusions are varied, it is not limited to three different heights H1, H3, and H4; two or four or more different heights may also be used. Moreover, it is not limited to arranging multiple first and second protrusions in circumferential order in height; they may also be arranged irregularly.

[0073] Furthermore, when offsetting multiple first and second protrusions radially, the positions may be not limited to three locations (outer, center, and inner) in the radial direction, but may also be two or four or more locations. When the position of multiple first and second protrusions is limited to one location, it does not have to be limited to the radial center. Moreover, the arrangement of multiple first and second protrusions circumferentially is not limited to the radial center, outer, and inner order, but may also be irregular.

[0074] In the above embodiment, the case where there is only one row of first through holes 24 and second through holes 27 arranged in the circumferential direction was described, but they may be arranged in two or more rows in the radial direction. In this case, the number, dimensions, and shape of the first through holes 24 and second through holes 27 on the radial inner side and the first through holes 24 and second through holes 27 on the radial outer side may be changed.

[0075] In the above embodiment, we have described a case where one first projection 25, 25a, 25b, 51, 52 is provided for each first grid 23b, and one second projection 28, 28a, 28b is provided for each second grid 26b, but we are not limited to this. For example, two or more first projections 25, 25a, 25b, 51, 52 may be provided for one first grid 23b, and two or more second projections 28, 28a, 28b may be provided for one second grid 26b. Furthermore, it is not necessary to provide first projections 25, 25a, 25b, 51, 52 or second projections 28, 28a, 28b for some of the multiple first grids 23b or second grids 26b.

[0076] In the above embodiment, the case in which the movable plate 30 floats in the liquid of the containment space 29 was described, but the embodiment is not limited to this. For example, the movable plate 30 may be sandwiched between the first partition plate 23 and the second partition plate 26. Alternatively, the movable plate 30 may divide the containment space 29 vertically, preventing the liquid from moving between the first liquid chamber 17 and the second liquid chamber 18 through the containment space 29.

[0077] In the above embodiment, the case in which the annular projections 31 to 34 are continuous in the circumferential direction was described, but it is not limited to this. For example, a slit may be provided in a part of the circumferential direction of the annular projections 31 to 34. Also, the multiple annular projections 31 to 34 may have different heights. The multiple annular projections 31 to 34 are not limited to being arranged on concentric circles, but their centers may be offset from each other. [Explanation of Symbols]

[0078] 10. Liquid-filled vibration isolation device 11. First Member 12 Second Member 13 Vibration Isolation Base 15 diaphragm 17 1st liquid chamber 18 2nd liquid chamber 19. First orifice (orifice) 20, 40, 50 partitions 23,41 First partition plate 23b 1st grid 23c, 26c Inner ring section (ring section) 23d, 26d Outer ring section (ring section) 24 First through hole 25,25a,25b,51,52 1st protrusion 26,42 Second partition plate 26b 2nd grid 27 Second through hole 28,28a,28b 2nd protrusion 30 Movable plate 31, 32, 33, 34 Annular projections

Claims

1. A first member and a cylindrical second member, An elastic vibration-damping base connecting the first member and the second member, An elastic diaphragm attached to the second member and forming a liquid chamber between it and the vibration-damping base, A partition body divides the aforementioned liquid chamber into a first liquid chamber and a second liquid chamber, It comprises an orifice connecting the first liquid chamber and the second liquid chamber, The partition body has a first partition plate facing the first liquid chamber, having a plurality of first through holes that penetrate in the thickness direction and are arranged in the circumferential direction, and a plurality of first grids formed between the plurality of first through holes, A second partition plate facing the second liquid chamber, The device comprises a plurality of first through holes and a movable elastic plate positioned between the first partition plate and the second partition plate so as to face the first grid, Multiple first protrusions project from the multiple first grids toward the movable plate, The second partition plate has a plurality of second through holes that penetrate the plate thickness direction and are arranged in the circumferential direction in the portion opposite to the movable plate, It comprises a plurality of second grids formed between a plurality of the second through holes, A liquid-filled vibration isolation device characterized in that a plurality of second protrusions project from a plurality of second grids toward the movable plate.

2. The liquid-filled vibration isolation device according to claim 1, characterized in that the plurality of first grids and the plurality of second grids are arranged offset from each other in the circumferential direction.

3. The liquid-filled vibration isolation device according to claim 1 or 2, characterized in that the multiple first protrusions are of different heights.

4. The liquid-filled vibration isolation device according to claim 1 or 2, characterized in that some of the multiple first protrusions have positions that protrude from the first grid that are shifted radially.

5. The first partition plate has an annular portion that extends radially outward and inward from the first grid and is continuous in the circumferential direction, The movable plate is provided with an annular projection that protrudes so as to be able to contact the annular portion, The liquid-filled vibration isolation device according to claim 1 or 2, characterized in that the first projection is lower than the annular projection.

6. The liquid-filled vibration isolation device according to claim 1 or 2, characterized in that the movable plate is formed in the shape of a disc or an annular plate and floats in the liquid so as to be rotatable in the circumferential direction of the movable plate relative to the first partition plate and the second partition plate.

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