Vibration isolation device

Abstract

The partition member (17) has a first hole passage (25) extending from the main liquid chamber (15) toward the sub liquid chamber (16) side, and a second hole passage (26) extending from the sub liquid chamber toward the main liquid chamber side and connected to the first hole passage, the first hole passage extending from the main liquid chamber toward one side in the circumferential direction, the second hole passage extending from a connection portion connected to the first hole passage toward the other side in the circumferential direction, and a short-cut passage (20) directly linking the sub liquid chamber and the connection portion of the first and second hole passages is formed in the partition member.

Description

TECHNICAL FIELD

[0001] The present application relates to a vibration isolation device.

[0002] This application is based on Japanese Priority Application No. 2020-170269 filed on October 8, 2020, the content of which is incorporated herein by reference. BACKGROUND

[0003] As a vibration isolation device, there is known a device as shown in Patent Document 1, which includes a first mounting member in the shape of a cylinder coupled to either one of a vibration generating portion and a vibration receiving portion, a second mounting member coupled to the other one of the vibration generating portion and the vibration receiving portion, an elastic body linking the first mounting member and the second mounting member, and a partition member partitioning a liquid chamber in the first mounting member into a main liquid chamber and a sub liquid chamber, the main liquid chamber having the elastic body in a portion of a partition wall, and an orifice passage is formed in the partition member to communicate the main liquid chamber and the sub liquid chamber.

[0004] Further, when a vibration is input to the vibration isolation device, the first mounting member and the second mounting member elastically deform the elastic body and relatively displace, and as the internal pressure of the main liquid chamber varies, the liquid flows through the orifice passage, thereby attenuating and absorbing the vibration.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: International Publication No. 2018 / 051627 SUMMARY

[0008] PROBLEMS ADDRESSED BY THE INVENTION

[0009] However, in the vibration isolation device of the above-described structure, in the case where the frequency is identical but the amplitude varies, there is a problem that it is difficult to attenuate and absorb the input vibration.

[0010] The present application has been made in view of such a situation, and aims to provide a vibration isolation device which can attenuate and absorb an input vibration even if the amplitude increases or decreases, as long as the frequency is identical.

[0011] SOLUTIONS FOR ADDRESSING THE PROBLEMS

[0012] To solve the above problems, a vibration isolation device according to one aspect of the present application includes: a first mounting member of a cylindrical shape coupled to either one of a vibration generating portion and a vibration receiving portion, and a second mounting member coupled to the other one; an elastic body coupling the first mounting member and the second mounting member; and a partition member partitioning a liquid chamber in the first mounting member into a main liquid chamber and a sub liquid chamber having the elastic body as a part of a partition wall, the partition member including: a first hole passage extending from the main liquid chamber toward the sub liquid chamber side; and a second hole passage extending from the sub liquid chamber toward the main liquid chamber side and connected to the first hole passage, the first hole passage extending from the main liquid chamber toward one side in a circumferential direction around a central axis of the first mounting member, the second hole passage extending from a connection portion connected to the first hole passage toward the other side in the circumferential direction, the partition member having a shortcut passage directly linking the sub liquid chamber and the first hole passage with the connection portion of the second hole passage.

[0013] EFFECTS OF THE INVENTION

[0014] According to the present application, input vibrations can be attenuated and absorbed even if the amplitude is increased or decreased, as long as the frequencies are equivalent. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 Fig. 1 is a longitudinal sectional view of a vibration isolation device according to one embodiment.

[0016] Figure 2 Fig. 2 is a II-II line cross-sectional view of the vibration isolation device of Fig. 1. Figure 1 DETAILED DESCRIPTION

[0017] Hereinafter, a vibration isolation device according to one embodiment will be described with reference to Figure 1 and Figure 2 Fig. 1 is a longitudinal sectional view of a vibration isolation device according to one embodiment.

[0018] The vibration isolation device 1 includes: a first mounting member 11 of a cylindrical shape coupled to either one of a vibration generating portion and a vibration receiving portion, and a second mounting member 12 coupled to the other one; an elastic body 13 coupling the first mounting member 11 and the second mounting member 12; and a partition member 17 partitioning a liquid chamber 14 in the first mounting member 11 into a main liquid chamber 15 and a sub liquid chamber 16 having the elastic body 13 as a part of a partition wall.

[0019] In a case where the vibration isolation device 1 is used as, for example, an engine mount of an automobile, the first mounting member 11 is coupled to a vehicle body as the vibration receiving portion, and the second mounting member 12 is coupled to an engine as the vibration generating portion. Thus, transmission of vibrations of the engine to the vehicle body can be suppressed.

[0020] ​In the illustrated example, the partition member 17 divides the liquid chamber 14 into the main liquid chamber 15 and the sub liquid chamber 16 along an axial direction along the center axis O of the first mounting member 11. That is, the partition member 17 divides the liquid chamber 14 into the main liquid chamber 15 on one side along the axial direction and the sub liquid chamber 16 on the other side along the axial direction.

[0021] Hereinafter, the main liquid chamber 15 side along the axial direction will be referred to as the upper side with respect to the partition member 17, and the sub liquid chamber 16 side will be referred to as the lower side. When the vibration isolation device 1 is viewed from the axial direction, a direction intersecting the center axis O will be referred to as the radial direction, and a direction around the center axis O will be referred to as the circumferential direction.

[0022] The first mounting member 11 includes an upper cylindrical portion 11a on the upper side, a lower cylindrical portion 11b having an inner diameter and an outer diameter smaller than those of the upper cylindrical portion 11a and located on the lower side, and a necked portion 11c linking the upper cylindrical portion 11a and the lower cylindrical portion 11b and continuously extending in the entire circumferential range. The inner peripheral surface of the lower cylindrical portion 11b is covered with a covering rubber. The covering rubber is integrally formed with the elastic body 13.

[0023] The second mounting member 12 is formed in a bar shape and is disposed coaxially with the center axis O. The second mounting member 12 is disposed on the inner side in the radial direction of the first mounting member 11. A flange portion 12a protruding toward the outer side in the radial direction is formed in the intermediate portion in the axial direction of the second mounting member 12. An internally threaded portion 12b is formed in the upper end surface of the second mounting member 12. A tapered portion 12c that is reduced in diameter as it goes toward the lower side is formed in the portion of the second mounting member 12 located on the lower side than the flange portion 12a. The flange portion 12a is located on the upper side than the first mounting member 11. The lower end portion of the second mounting member 12 is located on the lower side than the upper end opening rim of the first mounting member 11.

[0024] The elastic body 13 is formed in a ring shape and is disposed coaxially with the center axis O. The elastic body 13 links the upper cylindrical portion 11a of the first mounting member 11 and the tapered portion 12c of the second mounting member 12. The outer peripheral side of the elastic body 13 is integrally vulcanized and bonded to the inner peripheral surfaces of the upper cylindrical portion 11a and the necked portion 11c of the first mounting member 11, respectively. The inner peripheral side of the elastic body 13 is vulcanized and bonded to the tapered portion 12c of the second mounting member 12. The elastic body 13 extends toward the upper side as it goes from the outer side in the radial direction toward the inner side. The upper end opening portion of the first mounting member 11 is closed by the elastic body 13.

[0025] The elastic body 13 is integrally formed with a limit rubber 32 that covers the upper surface, the lower surface, and the outer peripheral surface of the flange portion 12a of the second mounting member 12.

[0026] In the lower end portion of the first mounting member 11, a cylindrical diaphragm ring 18 is liquid-tightly fitted with the covering rubber interposed. An outer peripheral portion of a diaphragm 19 formed of a rubber material or the like so as to be elastically deformable is vulcanization-bonded to the inner peripheral surface of the diaphragm ring 18. The diaphragm ring 18 is fixed to the first mounting member 11 by bending the lower end portion of the first mounting member 11 toward the radially inner side. The diaphragm 19 seals the lower end opening portion of the first mounting member 11.

[0027] A liquid chamber 14 for enclosing a liquid is formed in the first mounting member 11 by the diaphragm 19 and the elastic body 13. As the liquid to be enclosed in the liquid chamber 14, for example, ethylene glycol, water, or silicone oil, or the like can be cited.

[0028] The partition member 17 is formed in a flat disc shape. The partition member 17 is disposed coaxially with the center axis O. The partition member 17 is fitted in the first mounting member 11. The partition member 17 is sandwiched in the axial direction by the necked portion 11c of the first mounting member 11 and the diaphragm ring 18. The liquid chamber 14 in the first mounting member 11 is divided by the partition member 17 into a main liquid chamber 15 formed by the elastic body 13 and the partition member 17 and a sub liquid chamber 16 formed by the diaphragm 19 and the partition member 17. The diaphragm 19 is elastically deformed by expansion and contraction in accordance with the inflow and outflow of the liquid into and from the sub liquid chamber 16.

[0029] The partition member 17 is provided with a partition plate 31 that constitutes a part of the partition wall of each of the main liquid chamber 15 and the sub liquid chamber 16 and is provided so as to be elastically deformable, a first hole passage 25 that extends from the main liquid chamber 15 toward the sub liquid chamber 16 side, a second hole passage 26 that extends from the sub liquid chamber 16 toward the main liquid chamber 15 side and is connected to the first hole passage 25, an upper side member 34 that surrounds the partition plate 31 from the radially outer side, a lower side member 33 that is fitted in the upper side member 34, and a ring-shaped fixing member 38 that fixes the partition plate 31 to the upper side member 34.

[0030] Further, the partition member 17 can not have at least one of the upper side member 34, the lower side member 33, and the fixing member 38, and the upper side member 34, the lower side member 33, and the fixing member 38 can be integrally formed.

[0031] The partition plate 31 is formed of a rubber material or the like so as to be elastically deformable. The partition plate 31 is formed in a plate shape. The partition plate 31 has, for example, a circular shape when viewed in the axial direction.

[0032] Further, the partition plate 31 can have, for example, a rectangular shape or the like when viewed in the axial direction. The partition plate 31 is disposed coaxially with the center axis O. The partition plate 31 is not formed with a through-hole that penetrates in the axial direction. The partition plate 31 is provided so as not to collide with other members provided in the liquid chamber 14 when elastically deformed in conjunction with the input of vibration.

[0033] The upper member 34 has a fixed cylinder portion 34a that surrounds the partition 31 from the radially outer side, an annular fixed flange 34b that protrudes toward the radially inner side from the lower end opening edge of the fixed cylinder portion 34a, an annular upper flange 34c that protrudes toward the radially outer side from the lower end opening edge of the fixed cylinder portion 34a, an outer cylinder portion 34d that protrudes toward the lower side from the fixed cylinder portion 34a, and a lower flange 34e that protrudes toward the radially outer side from the lower end opening edge of the outer cylinder portion 34d.

[0034] The fixed cylinder portion 34a, the fixed flange 34b, the upper flange 34c, the outer cylinder portion 34d, and the lower flange 34e are disposed coaxially with the center axis O.

[0035] The outer peripheral edges of the upper flange 34c and the lower flange 34e are fitted in the lower cylinder portion 1 lb with the covering rubber interposed therebetween. A fixing member 38 is placed on the upper end opening edge of the fixed cylinder portion 34a, and the fixing member 38 is fixed to the upper member 34 by bolts or the like not shown. The outer peripheral edge portion of the partition 31 is fixed with the fixing member 38 and the fixed flange 34b interposed therebetween in the axial direction. Thus, the partition 31 is elastically deformed in the axial direction with the outer peripheral edge portion as a fixed end in accordance with a change in the internal pressure of the main liquid chamber 15.

[0036] The lower member 33 is fitted in the outer cylinder portion 34d of the upper member 34. The lower member 33 has an annular bottom plate portion 33a, an inner cylinder portion 33b that protrudes toward the upper side from the inner peripheral edge of the bottom plate portion 33a, and an annular upper plate portion 33d that protrudes toward the radially outer side from the upper end opening edge of the inner cylinder portion 33b.

[0037] The bottom plate portion 33a, the inner cylinder portion 33b, and the upper plate portion 33d are disposed coaxially with the center axis O.

[0038] The outer peripheral edge of the bottom plate portion 33a is fitted in the lower cylinder portion 1 lb with the covering rubber interposed therebetween. The outer peripheral portion in the upper surface of the bottom plate portion 33a abuts against the lower surface of the lower flange 34e of the upper member 34, and the inner peripheral portion in the upper surface of the bottom plate portion 33a is positioned at a position that is radially inward of the lower flange 34e and the outer cylinder portion 34d. The inner cylinder portion 33b is disposed radially inward of the outer cylinder portion 34d. The outer peripheral edge of the upper plate portion 33d is fitted in the outer cylinder portion 34d. The upper surface of the upper plate portion 33d abuts against the lower surface of the fixed flange 34b.

[0039] An opening portion (hereinafter referred to as a first communication hole) 21 of the first hole passage 25 on the main liquid chamber 15 side is formed in the upper flange 34c of the upper member 34. The first communication hole 21 opens in the axial direction toward the main liquid chamber 15. Alternatively, the first communication hole 21 can open in the radial direction toward the main liquid chamber 15.

[0040] An opening portion (hereinafter referred to as a second communication hole) 22 of the second hole passage 26 on the sub liquid chamber 16 side is formed in the inner cylindrical portion 33b of the lower side member 33. The second communication hole 22 is located at a position that is radially inward of the first communication hole 21. The circumferential positions of the second communication hole 22 and the first communication hole 21 are identical to each other. As shown in FIG. 2, the first communication hole 21 and the second communication hole 22 are adjacent to each other in the radial direction when viewed in the axial direction with the outer cylindrical portion 34d of the upper side member 34 and the second hole passage 26 interposed therebetween. The second communication hole 22 opens in the radial direction toward the sub liquid chamber 16. Alternatively, the second communication hole 22 can open in the axial direction toward the sub liquid chamber 16. The second communication hole 22 opens toward a portion of the sub liquid chamber 16 that is surrounded from the radially outer side by the first hole passage 25 and the second hole passage 26 and that is opposite the lower surface of the partition 31 in the axial direction. Figure 2

[0041] The first hole passage 25 extends from the main liquid chamber 15 toward one side in the circumferential direction. The first hole passage 25 is formed by the covering rubber of the inner circumferential surface of the lower cylindrical portion lib and the upper flange 34c, the outer cylindrical portion 34d, and the lower flange 34e of the upper side member 34.

[0042] The first hole passage 25 is disposed in a range of an angle that is greater than 180° and less than 360° with the center axis O as the center. Alternatively, the range of the angle can be 180° or less, 360° or less, or greater than 360°.

[0043] The first hole passage 25 is located at a position that is lower than the partition 31. The first hole passage 25 is located at a position that is radially outward of the partition 31.

[0044] Here, the upper side member 34 is provided with an outer partition wall 34f that protrudes toward the radially outer side from the outer cylindrical portion 34d and that is engaged with the covering rubber of the inner circumferential surface of the lower cylindrical portion lib. The outer partition wall 34f divides both end portions in the circumferential direction of the first hole passage 25.

[0045] In the outer cylindrical portion 34d, a connection hole (connection portion) 27 that penetrates in the radial direction is formed in a portion that is located on the side opposite the side on which the first communication hole 21 is located when viewed in the axial direction with the outer partition wall 34f interposed therebetween in the circumferential direction. The connection hole 27 and the first communication hole 21 are adjacent to each other in the circumferential direction when viewed in the axial direction.

[0046] The connection hole 27 opens in the inner circumferential surface of an end portion (connection portion) of the first hole passage 25 that is divided in the circumferential direction and that is located radially inward toward the radially outer side. The connection hole 27 connects the end portion on one side in the circumferential direction in the first hole passage 25 and the second hole passage 26 in the radial direction.

[0047] ​The second passage 26 extends circumferentially from the connecting portion that connects to the first passage 25. The second passage 26 is located radially inward compared to the first passage 25. The radial positions of the second passage 26 and the outer periphery of the partition 31 are equal. The second passage 26 is formed by the outer cylinder portion 34d of the upper member 34 and the inner periphery, inner cylinder portion 33b, and upper plate portion 33d of the bottom plate portion 33a of the lower member 33. The second passage 26 is located below the partition 31.

[0048] The second aperture passage 26 is positioned with respect to the central axis O within an angle range greater than 180° and less than 360°. Alternatively, this angle range can be less than 180°, less than 360°, or greater than 360°. The angle ranges of the second aperture passage 26 and the first aperture passage 25 are identical to each other. Alternatively, the angle ranges of the second aperture passage 26 and the first aperture passage 25 can be different.

[0049] Here, as Figure 2 As shown, the lower member 33 has an inner partition wall 33f, which protrudes radially outward from the inner cylinder portion 33b and its outer periphery fits into the outer cylinder portion 34d of the upper member 34. The inner partition wall 33f divides the two circumferential ends forming the second passageway 26. The circumferential positions of the inner partition wall 33f and the outer partition wall 34f are identical to each other. The inner partition wall 33f and the outer partition wall 34f are arranged to be connected radially. The circumferential positions of the second passageway 26 and the first passageway 25 are identical to each other along their entire circumferential length. Alternatively, the circumferential positions of the second passageway 26 and the first passageway 25 may be different.

[0050] The connecting hole 27 opens into the inner surface of the end (connecting portion) of the second passage 26, which is located on the radially outer side and faces the radially inner side. The end of the second passage 26 on the circumferential side communicates with the end of the first passage 25 on the circumferential side via the connecting hole 27.

[0051] The second connecting hole 22 opens into the inner circumferential surface of the end of the second passage 26 that forms the other side of the circumferential division, located radially inward and facing radially outward. The other side of the second passage 26 is connected to the auxiliary liquid chamber 16 via the second connecting hole 22.

[0052] The partition member 17 has a shortcut passage 20 that directly connects the auxiliary liquid chamber 16 and the connection portion of the first orifice passage 25 and the second orifice passage 26. In this embodiment, the shortcut passage 20 opens at one end toward the circumferential side of the second orifice passage 26.

[0053] Further, the shortcut passage 20 can also open toward the end portion of the one side in the circumferential direction in the first hole passage 25 or the connection hole 27.

[0054] The shortcut passage 20 opens in the inner circumferential surface in the radially inner side of the inner surface of the second hole passage 26 toward the radially outer side. The shortcut passage 20 is formed in the inner cylinder portion 33b at the portion opposite to the connection hole 27 in the radial direction and dividing the end portion of the one side in the circumferential direction in the second hole passage 26. The shortcut passage 20 penetrates the inner cylinder portion 33b in the radial direction. The shortcut passage 20 is provided on the side opposite to the side where the second communication hole 22 is located, through the inner side partition wall 33f in the circumferential direction.

[0055] The shortcut passage 20 and the second communication hole 22 are adjacent to the inner side partition wall 33f in the circumferential direction.

[0056] The shortcut passage 20 opens in the radial direction toward the portion in the sub liquid chamber 16 surrounded by the first hole passage 25 and the second hole passage 26 from the radially outer side and opposite to the lower surface of the partition plate 31 in the axial direction. Further, the shortcut passage 20 can also open in the axial direction toward the sub liquid chamber 16. The flow path length of the shortcut passage 20 is shorter than the flow path lengths of the first hole passage 25 and the second hole passage 26 respectively.

[0057] The axial positions of at least a portion of the shortcut passage 20 and the second communication hole 22 respectively are identical to each other. The axial size of the shortcut passage 20 is smaller than the axial size of the second communication hole 22, and the axial position where the shortcut passage 20 is located is included in the axial position where the second communication hole 22 is located.

[0058] The flow path cross-sectional area of the shortcut passage 20 is set to be, for example, 1.7 mm 2 In the above, the flow path cross-sectional area of the shortcut passage 20 is smaller than the flow path cross-sectional areas of the end portions of the one side in the circumferential direction of the first hole passage 25 and the second hole passage 26 respectively, and the flow path cross-sectional area of the connection hole 27. The flow path cross-sectional area of the shortcut passage 20 is smaller than the flow path cross-sectional areas of the first communication hole 21 and the second communication hole 22 respectively.

[0059] The flow path length of the first hole passage 25 is longer than the flow path length of the second hole passage 26, and the flow path cross-sectional area of the first hole passage 25 is larger than the flow path cross-sectional area of the second hole passage 26. The flow resistances of the first hole passage 25 and the second hole passage 26 respectively are tuned so that the resonance frequencies of the passages 25, 26 respectively become the frequency of, for example, the torsional vibration or the like.

[0060] Further, the flow resistances of the first hole passage 25 and the second hole passage 26 respectively can be different from each other, or can be identical to each other.

[0061] Next, the effects of the vibration isolation device 1 configured as above will be described.

[0062] When the vibration is input to the vibration isolation device 1 and the first mounting member 11 and the second mounting member 12 relatively displace, the elastic body 13 that links the first mounting member 11 and the second mounting member 12 to each other elastically deforms. At this time, the internal pressure of the main liquid chamber 15 varies, the liquid passes between the main liquid chamber 15 and the sub liquid chamber 16 via the first hole passage 25 and the second hole passage 26 and performs resonance, thereby attenuating the vibration, absorbing the vibration. In addition, when the internal pressure of the main liquid chamber 15 varies, the partition 31 elastically deforms in the axial direction with the outer peripheral edge portion as a fixed end, thereby being able to suppress dynamic stiffness (Japanese: dynamic spring).

[0063] As explained above, according to the vibration isolation device 1 of the present embodiment, the first hole passage 25 extends from the main liquid chamber 15 toward one side in the circumferential direction, and the second hole passage 26 extends from the connection portion connected to the first hole passage 25 toward the other side in the circumferential direction, and thus, when the liquid flows in the first hole passage 25 and the second hole passage 26 from either one of the main liquid chamber 15 and the sub liquid chamber 16 toward the other, the flow direction in the first hole passage 25 and the flow direction in the second hole passage 26 become opposite directions. Thus, for example, compared with a case where the first hole passage 25 and the second hole passage 26 are directly linked in the circumferential direction so that each of the flow directions becomes the same direction, it is easy to increase or decrease the flow resistance of the liquid in response to an increase or decrease in the amplitude of the input vibration, that is, an increase or decrease in the flow rate of the liquid flowing in the first hole passage 25 and the second hole passage 26. Thereby, as long as the frequencies are the same, it is possible to generate liquid column resonance in the first hole passage 25 and the second hole passage 26 even if the amplitude increases or decreases, and to attenuate and absorb the input vibration.

[0064] The bypass passage 20 is formed in the partition member 17 so as to directly link the sub liquid chamber 16 and the connection portion of the first hole passage 25 and the second hole passage 26, and thus, when the vibration is input, a part of the liquid that has reached the connection portion of the first hole passage 25 and the second hole passage 26 can be discharged to the sub liquid chamber 16 via the bypass passage 20, it is possible to suppress the stagnation of the liquid at the connection portion, to smoothly flow the liquid in the first hole passage 25 and the second hole passage 26, and to suppress the dynamic stiffness.

[0065] The first hole passage 25 and the second hole passage 26 are arranged so as to be connected to each other in the radial direction, and thus, it is possible to suppress an increase in the volume in the axial direction of the vibration isolation device 1.

[0066] The flow path cross-sectional area of the bypass passage 20 is smaller than the flow path cross-sectional area of the connection portion of the first hole passage 25 and the second hole passage 26, and thus, it is possible to easily tune the resonance frequency and the like of the first hole passage 25 and the second hole passage 26.

[0067] The partition member 17 has a partition 31 that constitutes a part of the partition wall of each of the main liquid chamber 15 and the sub liquid chamber 16 and is provided so as to be elastically deformable, and thus, at the time of input of vibration, the partition 31 can be elastically deformed, and the dynamic stiffness can be suppressed to be low.

[0068] In particular, at the time of input of vibration of a micro amplitude (for example, 0.05 mm to 0.2 mm), the partition 31 can be elastically deformed so as to suppress the dynamic stiffness to be low, and at the time of input of vibration of an amplitude larger than the amplitude (for example, 0.2 mm to 1.0 mm), as long as the frequency is equivalent, even if the amplitude is increased or decreased, the liquid can be circulated in the first hole passage 25 and the second hole passage 26 so as to attenuate the input vibration and absorb the input vibration.

[0069] The partition 31 is provided so as to be elastically deformable in a manner of constituting a part of the partition wall of each of the main liquid chamber 15 and the sub liquid chamber 16, and for example, is not a so-called movable partition (Japanese: gata menburen) that is housed in a housing chamber that communicates with both the main liquid chamber 15 and the sub liquid chamber 16 in a movable manner, and thus, it is possible to suppress the generation of a knocking sound due to a collision of the partition 31 with other members at the time of input of vibration.

[0070] The short-circuit passage 20 is opened in the radial direction toward a portion in the sub liquid chamber 16 that is surrounded from the outside in the radial direction by the first hole passage 25 and the second hole passage 26 and that is opposite to the partition 31, and thus, it is possible to make the short-circuit passage 20 not easily blocked by a member such as a diaphragm 19 that constitutes a part of the partition wall of the sub liquid chamber 16, and it is possible to smoothly flow the liquid from the short-circuit passage 20 to the sub liquid chamber 16.

[0071] Furthermore, the scope of the present application is not limited to the described embodiments, and various modifications can be applied within the scope of the gist of the present application.

[0072] The relative positions of the first hole passage 25 and the second hole passage 26 can be appropriately changed, for example, such that the second hole passage 26 is provided at a position that is radially outside the first hole passage 25, or such that the first hole passage 25 and the second hole passage 26 are connected to each other in the axial direction.

[0073] The positions of the first hole passage 25 and the second hole passage 26 with respect to the partition 31 can be appropriately changed, for example, such that the axial positions are equivalent to each other.

[0074] The connection hole 27 can be opened toward a middle portion of the circumference of at least one of the first hole passage 25 and the second hole passage 26.

[0075] In the embodiment, the compression type vibration isolation device 1 in which positive pressure is applied to the main liquid chamber 15 by the support load is described, but the application is also possible to a suspension type vibration isolation device in which the main liquid chamber 15 is installed on the lower side in the vertical direction and the sub liquid chamber 16 is installed on the upper side in the vertical direction, and in which negative pressure is applied to the main liquid chamber 15 by the support load.

[0076] The vibration isolation device 1 of the present application is not limited to the engine mount of the vehicle, and is also applicable to a place other than the engine mount. For example, it is also applicable to a cabin support or a bushing for a vehicle, or to a mount for a generator mounted on a construction machine, or to a mount for a machine installed in a factory or the like.

[0077] Further, in a range not departing from the gist of the present application, the components in the above-described embodiments can be appropriately replaced with well-known components, and the above-described embodiments and modified examples can be appropriately combined.

[0078] According to the vibration isolation device of the present application, the first hole passage (25) extends from the main liquid chamber (15) toward one side in the circumferential direction, and the second hole passage (26) extends from the connection portion connected to the first hole passage toward the other side in the circumferential direction, so that the flow direction in the first hole passage and the flow direction in the second hole passage become opposite directions when the liquid flows in the first hole passage and the second hole passage from either one of the main liquid chamber and the sub liquid chamber toward the other. Thus, for example, compared with a case in which the first hole passage and the second hole passage are directly connected in the circumferential direction so that the flow directions are the same, the flow resistance of the liquid can be easily increased or decreased in response to an increase or decrease in the amplitude of the input vibration, that is, an increase or decrease in the flow rate of the liquid flowing in the first hole passage and the second hole passage. Thus, as long as the frequency is the same, the liquid column resonance can be generated in the first hole passage and the second hole passage even if the amplitude increases or decreases, so that the input vibration is attenuated and absorbed.

[0079] The shortcut passage (20) directly connecting the sub liquid chamber and the connection portion of the first hole passage and the second hole passage is formed in the partition member, so that when the vibration is input, a part of the liquid that has reached the connection portion of the first hole passage and the second hole passage can be discharged to the sub liquid chamber via the shortcut passage, the stagnation of the liquid at the connection portion can be suppressed, the liquid can smoothly flow in the first hole passage and the second hole passage, and the dynamic stiffness can be suppressed.

[0080] In a case where the first hole passage and the second hole passage are arranged to be connected to each other in the radial direction, the volume in the axial direction of the vibration isolation device can be suppressed from becoming large.

[0081] In the configuration, the flow path cross-sectional area of the short path can be smaller than the flow path cross-sectional area of the connection portion of the first hole path and the second hole path.

[0082] In this case, the flow path cross-sectional area of the short path is smaller than the flow path cross-sectional area of the connection portion of the first hole path and the second hole path, and thus the resonance frequency or the like of the first hole path and the second hole path can be easily tuned.

[0083] In the configuration, the partition member can include a partition plate that constitutes a part of the partition wall of each of the main liquid chamber and the sub liquid chamber and is provided to be elastically deformable.

[0084] In this case, the partition member includes a partition plate that constitutes a part of the partition wall of each of the main liquid chamber and the sub liquid chamber and is provided to be elastically deformable, and thus the partition plate can be elastically deformed at the time of vibration input, and the dynamic stiffness can be suppressed to be low.

[0085] The partition plate is provided to be elastically deformable in a manner of constituting a part of the partition wall of each of the main liquid chamber and the sub liquid chamber, for example, is not a so-called movable partition plate that is housed in a housing chamber that communicates with both the main liquid chamber and the sub liquid chamber in a movable manner, and thus the partition plate colliding with other members at the time of vibration input to generate a knocking sound can be suppressed.

[0086] In the configuration, the short path can be opened in the radial direction toward a portion in the sub liquid chamber that is surrounded from the outside in the radial direction by the first hole path and the second hole path and is opposite to the partition plate.

[0087] In this case, the short path is opened in the radial direction toward a portion in the sub liquid chamber that is surrounded from the outside in the radial direction by the first hole path and the second hole path and is opposite to the partition plate, and thus the short path can not be easily blocked by a member such as a diaphragm that constitutes a part of the partition wall of the sub liquid chamber, and liquid can smoothly flow from the short path to the sub liquid chamber.

[0088] INDUSTRIAL APPLICABILITY

[0089] The present application can be applied to a vibration isolation device having a main liquid chamber and a sub liquid chamber in which liquid is enclosed.

[0090] REFERENCE NUMERALS

[0091] 1. A vibration isolation device; 11. A first mounting member; 12. A second mounting member; 13. An elastic body; 14. A liquid chamber; 15. A main liquid chamber; 16. A sub liquid chamber; 17. A partition member; 20. A short path; 25. A first hole path; 26. A second hole path; 27. A connection hole; 31. A partition plate; O. A center axis.

Claims

1. A vibration isolation device, wherein, This vibration isolation device has the following features: A cylindrical first mounting member connected to either the vibration generating part or the vibration receiving part, and a second mounting member connected to the other; An elastomer that connects the first mounting member and the second mounting member; as well as A partition member that divides the liquid chamber within the first mounting member into a main liquid chamber and a secondary liquid chamber, each having the elastomer in a portion of the partition wall. The separating member includes: The first passageway extends from the main liquid chamber toward the auxiliary liquid chamber; The second passage extends from the auxiliary liquid chamber toward the main liquid chamber and connects to the first passage; as well as The partition, which is plate-shaped, forms part of the partition wall between the main liquid chamber and the auxiliary liquid chamber, and its outer peripheral edge is fixed at one end, allowing it to elastically deform in the axial direction. The first passageway extends from the main liquid chamber toward one side in the circumferential direction around the central axis of the first mounting member. The second passage extends from the connection portion connected to the first passage toward the other side in the circumferential direction. The flow direction of the liquid in the first orifice passage is opposite to the flow direction in the second orifice passage. The partition member has a shortcut passage that directly connects the auxiliary liquid chamber and the first orifice passage to the connection portion of the second orifice passage. The shortcut passage is radially oriented toward the portion of the auxiliary liquid chamber that is radially surrounded from the outside by the first and second orifice passages and opposite to the partition.

2. The vibration isolation device according to claim 1, wherein, The flow path cross-sectional area of ​​the shortcut path is smaller than the flow path cross-sectional area of ​​the connecting portion of the first hole path and the second hole path.

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