Fluid-enclosed vibration isolator

Abstract

This invention provides a fluid-sealed vibration damping device with a novel vibration damping mechanism and a diverse structure that easily handles vibration damping characteristics. In the fluid-sealed vibration damping device (10), a switching valve (68) is disposed inside the fluid passage (92) that passes through the partition member (40) and communicates with the main liquid chamber (80) and the auxiliary liquid chamber (82). The valve protrudes from one wall surface (94) of the fluid passage (92) towards the other wall surface (96). A gap (98) is provided between the switching valve (68) and the other wall surface (96). The switching valve (68) extends along the length of the fluid passage (92). 8) The tilting displacement in a head-shaking manner causes the front end of the switching valve (68) to abut against the wall (96) on the other side of the fluid passage (92), thereby forming a switching mechanism for a closed gap (98). A fin-shaped protrusion (72) capable of elastic deformation is provided, which can protrude from the front end of the switching valve (68) to the wall (96) on the other side of the fluid passage (92). A leakage passage (100) is formed between the protruding front end of the fin-shaped protrusion (72) and the wall (96) on the other side.

Description

Technical Field

[0001] The present invention relates to a fluid-sealed vibration damping device, for example, used in engine mounts of motor vehicles. Background Technology

[0002] Previously, vibration damping devices used in motor vehicle engine mounts and other applications were known. Additionally, fluid-sealed vibration damping devices are known that improve vibration damping performance by utilizing the flow of fluid in a main fluid chamber and a secondary fluid chamber.

[0003] However, fluid-sealed vibration damping devices have the following problems: while they exhibit excellent vibration damping performance within a pre-set specific frequency band, they fail to provide the intended vibration damping performance for vibration inputs at frequencies deviating from the specific frequency band. In response, the applicant has proposed a fluid-sealed vibration damping device in Japanese Patent Application Publication No. 2012-241842 (Patent Document 1), which provides effective vibration damping for vibration inputs across a wider frequency band. Patent Document 1 describes a vibration damping effect achieved in three different frequency bands based on the flow of fluid through the first and second flow paths, and also on hydraulic absorption based on the slight displacement of the switching section.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-241842 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, recently, the requirements for vibration damping characteristics have become more diverse. For example, different vibration damping characteristics are required for vibrations in areas with similar amplitudes and frequencies. There are also situations where there is a need to further improve the vibration damping performance for high-frequency vibrations and vibrations with smaller amplitudes.

[0009] The present invention addresses the problem of providing a fluid-sealed vibration damping device with a novel vibration damping mechanism and a diverse range of vibration damping characteristics.

[0010] means for solving problems

[0011] Hereinafter, preferred embodiments for mastering the present invention will be described. However, the embodiments described below are merely illustrative and can be appropriately combined with each other. Furthermore, the various constituent elements described in each embodiment can be identified and used as independently as possible, and can also be appropriately combined with any constituent elements described in other embodiments. Therefore, the present invention is not limited to the embodiments described below, and various other embodiments can be implemented.

[0012] The first type is a fluid-sealed vibration damping device, which has a structure in which a main liquid chamber and a secondary liquid chamber, both containing fluid, are separated by a partition member. The fluid-sealed vibration damping device has a fluid passage that passes through the partition member and communicates with the main liquid chamber and the secondary liquid chamber. Inside the fluid passage, a switching valve is disposed that protrudes from one wall of the fluid passage toward the other wall. A gap is provided between the switching valve and the other wall. The switching valve is configured to tilt at its base end. The front end of the switching valve abuts against the other wall of the fluid passage through a tilting displacement in the length direction of the fluid passage, thereby forming a switching mechanism that closes the gap. The fluid-sealed vibration damping device is provided with an elastically deformable fin-shaped protrusion that protrudes from the front end of the switching valve toward the other wall of the fluid passage. A leakage passage is formed between the protruding front end of the fin-shaped protrusion and the other wall.

[0013] According to the fluid-sealed vibration damping device constructed in this manner, in addition to switching the vibration damping characteristics by switching the connection and disconnection of the fluid passage through a switching valve, a further switching of the vibration damping characteristics is achieved by providing finned protrusions, thereby exerting a vibration damping effect against a wider variety of input vibrations. That is, it exerts a vibration damping effect through the fluid flow through the leakage path formed between the finned protrusions and another wall of the fluid passage, and when vibration input occurs due to the leakage path being substantially blocked, it exerts a vibration damping effect based on the elastic deformation of the finned protrusions.

[0014] The second method is based on the fluid-sealed vibration damping device described in the first method, wherein a recess is provided on the wall of the other side of the fluid passage, and the fin-shaped protrusion enters into the recess.

[0015] The fluid-sealed vibration damping device constructed according to this method can increase the protrusion length of the fin-shaped protrusions by inserting and arranging them into a recess in the wall opening on the other side of the fluid passage. Therefore, the vibration damping effect based on the elastic deformation of the fin-shaped protrusions can be more effectively utilized, and a greater degree of tuning freedom of the characteristics of the fin-shaped protrusions can be obtained.

[0016] The third method is based on the fluid-sealed vibration damping device described in the first or second method, wherein the fluid-sealed vibration damping device is provided with a rubber diaphragm clamped by the separating member, and the switching valve protrudes from the clamping part of the rubber diaphragm toward the wall of the other side of the fluid passage and extends circumferentially.

[0017] The fluid-sealed vibration damping device constructed according to this method has a large cross-sectional area for the fluid passage because the switching valve protrudes outwards from the periphery, and the connecting portion of the fluid passage is located on the periphery when the switching valve is open. By extending the switching valve circumferentially, the circumferential length of the fluid passage opened and closed by the switching valve is ensured, further facilitating a large cross-sectional area for the fluid passage. Furthermore, because the fin-shaped protrusions outwards from the switching valve, a leakage passage is formed between the fin-shaped protrusion and the wall surface of the outer periphery of the fluid passage, making it easy to obtain a large cross-sectional area for the leakage passage.

[0018] The fourth method is based on the fluid-sealed vibration damping device described in the third method, wherein the switching valve is provided to protrude from the clamping portion of the rubber diaphragm to the outer periphery throughout the entire circumference, and the fin-shaped protrusions are provided to protrude from the outer periphery of the switching valve throughout the entire circumference.

[0019] The fluid-sealed vibration damping device constructed according to this method, by arranging switching valves throughout the entire circumference, allows for a large degree of freedom in setting the circumferential length of the fluid passage opened and closed by the switching valves, thus achieving a large degree of tuning freedom for the fluid passage. Furthermore, by providing fin-shaped protrusions protruding from the outer circumference of the switching valves throughout the entire circumference, the circumferential length of the leakage passage can be set with a large degree of freedom, further achieving a large degree of tuning freedom for the leakage passage. The size of the area of ​​hydraulic pressure acting on the fin-shaped protrusions can be set with a large degree of freedom, allowing for a large degree of tuning freedom for the vibration damping characteristics exerted by the fin-shaped protrusions.

[0020] The fifth method is based on the fluid-sealed vibration damping device described in any one of the first to fourth methods, wherein the front end of the fin-shaped protrusion has a thick-walled front end that is formed as thick-walled in the length direction of the fluid passage compared to the base end of the fin-shaped protrusion.

[0021] According to the fluid-sealed vibration damping device constructed in this way, since the fin-shaped protrusion has a thick-walled front end, the base end of the fin-shaped protrusion becomes thin-walled, the spring constant of the base end becomes smaller, and the front end of the fin-shaped protrusion becomes thick-walled, thereby stabilizing the shape of the front end that is prone to deviation during manufacturing.

[0022] The sixth method is based on the fluid-sealed vibration damping device described in any of the first to fifth methods, wherein the front end of the fin-shaped protrusion is formed as an approach portion that is circumferentially separated from the wall of the other side of the fluid passage, and the leakage passage is formed through this approach portion.

[0023] The fluid-sealed vibration damping device constructed according to this method has finned protrusions that are located away from the wall on the other side of the fluid passage at the point where the leakage passage is formed. Therefore, even if the finned protrusions are attached to the wall on the other side of the fluid passage, they will not obstruct the flow of fluid through the leakage passage. Thus, the vibration damping effect based on the leakage passage can be stably achieved.

[0024] The seventh method is based on the fluid-sealed vibration damping device described in any of the first to sixth methods, wherein the fin-shaped protrusions abut against the wall of the other side of the fluid passage all around the circumference, and the fin-shaped protrusions separate from the other wall due to elastic deformation to form the leakage passage.

[0025] The fluid-sealed vibration damping device constructed in this manner can vary its vibration damping characteristics more greatly by switching the connection and disconnection of leakage paths through the fin-shaped protrusions.

[0026] The eighth embodiment is based on the fluid-sealed vibration damping device described in any of the first to seventh embodiments, wherein the front end of the switching valve is formed to extend to both sides in the length direction of the fluid passage, and the fin-shaped protrusion protrudes from the middle portion of the front end of the switching valve in the length direction of the fluid passage.

[0027] According to this method, the fluid-sealed vibration damping device, through the tilting displacement of the switching valve in a swaying manner, causes the two sides of the fluid passage at the front end of the switching valve to abut against the inner surface of the wall on the other side of the fluid passage, thereby reliably cutting off the fluid passage. Because fin-shaped protrusions extend from the middle portion of the front end of the switching valve, the abutment of the switching valve against the inner surface of the wall on the other side of the fluid passage is not easily obstructed by the fin-shaped protrusions during the swaying displacement of the switching valve.

[0028] The ninth method is based on the fluid-sealed vibration damping device described in any of the first to eighth methods, wherein the fluid-sealed vibration damping device is provided with a throttling passage that connects the main liquid chamber and the auxiliary liquid chamber to each other, and the resonant frequency of the fluid flow through the throttling passage is set to a frequency lower than the resonant frequency of the fluid flow through the fluid passage.

[0029] The fluid-sealed vibration damping device constructed according to this method can utilize the vibration damping effect generated by the fluid flow through the throttling path. Furthermore, when vibrations are input at frequencies higher than the resonant frequency of the fluid flow through the throttling path, the vibration damping effect generated by the fluid flow through the fluid passage is utilized, thereby preventing high-dynamic springing caused by substantial blockage of the throttling path.

[0030] Invention Effects

[0031] According to the present invention, a diverse fluid-sealed vibration damping device with a novel vibration damping mechanism can be provided, which can easily cope with vibration damping characteristics. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of the engine bracket as a first embodiment of the present invention.

[0033] Figure 2 It constitutes Figure 1 An exploded perspective view of the partition components of the engine mount shown.

[0034] Figure 3 It constitutes Figure 1 A top view of the elastic movable part of the engine mount shown.

[0035] Figure 4 yes Figure 3 Sectional view IV-IV.

[0036] Figure 5 It is Figure 1 The enlarged cross-sectional view of a portion of the engine mount is a diagram showing the state of input vibration.

[0037] Figure 6 It is Figure 1 The enlarged cross-sectional view of a portion of the engine mount is a diagram showing the state of input idling vibration.

[0038] Figure 7 It is Figure 1 The enlarged cross-sectional view of a portion of the engine mount is a diagram showing the state of vibration intermediate between inputting shaking vibration and idling vibration. Detailed Implementation

[0039] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0040] exist Figure 1In this paper, as a first embodiment of a fluid-sealed vibration damping device according to the present invention, an engine mount 10 for a motor vehicle is shown. The engine mount 10 has a structure in which a first mounting member 12 and a second mounting member 14 are elastically connected by a main body rubber elastomer 16. In the following description, in principle, the vertical direction refers to the direction of the central axis of the mount. Figure 1 The up and down directions in the middle.

[0041] The first mounting member 12 is a rigid member made of metal or the like. The first mounting member 12 has a fixing member 18 in the shape of a generally circular plate. A through hole 20 extending vertically is provided in the radial center portion of the fixing member 18. A mounting bolt 22 is inserted into the through hole 20 from below and upwards, and the mounting bolt 22 is fixed to the fixing member 18.

[0042] The second mounting member 14 is a rigid member made of metal or the like, and is formed into a generally cylindrical shape with thin walls and a large diameter. The second mounting member 14 has an annular stepped portion 24 in the middle part along the axial direction. The upper side of the stepped portion 24 is a large-diameter cylindrical portion 26, and the lower side is a small-diameter cylindrical portion 28, thus forming an overall stepped cylindrical shape.

[0043] The first mounting member 12 is disposed on a central axis substantially the same as that of the second mounting member 14 on its upper side. The first mounting member 12 and the second mounting member 14 are elastically connected by a main rubber elastomer 16. The main rubber elastomer 16 has a generally frustum-shaped, thick-walled structure with a large diameter. The first mounting member 12 is vulcanized and bonded to the end with a small diameter, and the second mounting member 14 is overlapped and vulcanized and bonded to the outer peripheral surface of the end with a large diameter. The main rubber elastomer 16 is formed as an integral vulcanized molded part having the first mounting member 12 and the second mounting member 14.

[0044] The main rubber elastomer 16 has a large-diameter recess 30 that opens on the lower surface, which is the large-diameter side end face. The large-diameter recess 30 is generally formed in a reverse mortar shape, gradually becoming larger in diameter from the upper bottom surface toward the opening side, and extending vertically with a generally constant diameter near the opening.

[0045] A sealing rubber layer 32 is integrally formed on the main rubber elastomer 16. The sealing rubber layer 32 has a generally cylindrical shape with thin walls and a large diameter, extending downward from the outer periphery of the opening of the large-diameter recess 30. The sealing rubber layer 32 is fixed to the inner peripheral surface of the small-diameter cylindrical portion 28 of the second mounting member 14, and the inner peripheral surface of the second mounting member 14 is substantially entirely covered by the main rubber elastomer 16 and the sealing rubber layer 32.

[0046] A flexible membrane 34 is installed at the lower opening of the second mounting member 14. The flexible membrane 34 is a circular rubber membrane with a relaxed outer periphery and an upward-protruding dome-shaped inner periphery. The outer periphery of the flexible membrane 34 is fixed to an annular fixing member 36. With the fixing member 36 inserted into the lower opening of the second mounting member 14, the fixing member 36 is fixed to the second mounting member 14 by performing a diameter reduction process such as octagonal reduction. Thus, the flexible membrane 34 is installed on the second mounting member 14, and the lower opening of the second mounting member 14 is liquid-tightly sealed by the flexible membrane 34.

[0047] By mounting the flexible membrane 34 to the second mounting member 14, a fluid-sealing region 38 is formed between the main rubber elastomer 16 and the flexible membrane 34. The fluid-sealing region 38 is liquid-tightly sealed relative to the external space and contains an incompressible fluid. The incompressible fluid is preferably, for example, water, ethylene glycol, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof. To effectively utilize the vibration damping effect based on fluid flow, the incompressible fluid is preferably a low-viscosity fluid with a viscosity of 0.1 Pa·s or less.

[0048] A partition member 40 is disposed in the fluid inlet region 38. The partition member 40 is integrally formed in a generally circular plate shape. Figure 2 As shown, the partition member 40 has a first partition plate 42 and a second partition plate 44.

[0049] The first partition plate 42 is a rigid component made of synthetic resin, metal, etc., and is integrally formed into a generally circular plate shape. The first partition plate 42 has a fitting recess 45 with an opening on its lower surface at its radial center. The first partition plate 42 has a cut-out portion 46 with openings on both its lower and outer peripheral surfaces at its outer periphery. The first partition plate 42 has a receiving recess 48 with an opening on its lower surface at its radial center, located further outward than the fitting recess 45 and further inward than the cut-out portion 46. A first overflow hole 50 extending vertically is formed in the inner peripheral portion of the receiving recess 48. A first flow path forming hole 52 extending vertically is formed in the outer peripheral portion of the receiving recess 48.

[0050] The second partition plate 44 is a rigid component made of synthetic resin or metal, and is integrally formed into a generally circular plate shape. The second partition plate 44 has an upwardly protruding fitting protrusion 53 at its radial center. The second partition plate 44 has a second overflow hole 54 extending vertically and a second flow path forming hole 56 extending vertically and extending vertically beyond the outer periphery of the second overflow hole 54 at its radial center.

[0051] The first partition plate 42 and the second partition plate 44 overlap vertically. The fitting protrusion 53 of the second partition plate 44 is embedded in the fitting recess 45 of the first partition plate 42, and the inner peripheral wall of the cut-shaped portion 46 of the first partition plate 42 is externally fitted onto the upper outer peripheral surface of the second partition plate 44. The first partition plate 42 and the second partition plate 44 are positioned relative to each other.

[0052] By combining the first partition plate 42 and the second partition plate 44, the lower opening of the cut-shaped portion 46 of the first partition plate 42 is blocked by the second partition plate 44, forming a circumferential groove 58 extending in the circumferential direction on the outer peripheral surface. In this embodiment, the circumferential groove 58 extends for less than one revolution, but it may extend in a spiral shape or the like for more than one revolution in the circumferential direction.

[0053] Furthermore, the opening of the recess 48 is covered by the second partition plate 44, and a receiving space 60 is formed between the first partition plate 42 and the second partition plate 44. The receiving space 60 is an annular space extending around the peripheral wall of the fitting recess 45, with a first overflow hole 50 and a second overflow hole 54 connected in the inner peripheral portion, and a first flow path forming hole 52 and a second flow path forming hole 56 connected in the outer peripheral portion.

[0054] An elastic movable body 62, which serves as a rubber membrane, is disposed in the receiving space 60. For example... Figure 3 , Figure 4 As shown, the elastic movable body 62 is generally annular and is formed of a rubber elastomer. The elastic movable body 62 has a clamping portion 64 that is clamped between the first partition plate 42 and the second partition plate 44. The clamping portion 64 is formed as an annular shape that extends continuously in the circumferential direction with a substantially constant cross-sectional shape. It is clamped between the first partition plate 42 and the second partition plate 44 at a position that is closer to the outer periphery than the first overflow hole 50 and the second overflow hole 54 and closer to the inner periphery than the first flow path forming hole 52 and the second flow path forming hole 56, and is thus fixed to the partition member 40.

[0055] An overflow valve 66 is provided on the inner circumferential side of the clamping portion 64. The overflow valve 66 is integrally formed with the clamping portion 64 and protrudes from the clamping portion 64 toward the inner circumference. More specifically, the base portion of the overflow valve 66 protrudes from the clamping portion 64 toward the inner circumference in a substantially axially perpendicular direction, and the front end portion protrudes from the base portion toward the inner circumferential side. The cross-sectional shape of the top portion of the overflow valve 66 is an inclined shape in which the upper and lower surfaces slope toward the upper side of the first partition plate 42 toward the inner circumference. The thickness of the front end portion of the overflow valve 66 gradually decreases in the vertical direction toward the inner circumference. The overflow valve 66 is located on the extension line of the first overflow hole 50 and the second overflow hole 54 when the elastic movable body 62 is disposed in the receiving space 60. When the elastic movable body 62 is disposed in the receiving space 60, the front end portion of the overflow valve 66 is pressed against the inner circumferential wall of the receiving space 60.

[0056] The elastic movable body 62 has a switching valve 68 protruding from the clamping part 64 toward the outer periphery. The switching valve 68 is annular in shape extending circumferentially and symmetrical in the vertical direction. The inner and outer peripheral surfaces of the switching valve 68 are cylindrical surfaces, and the upper and lower end faces are conical surfaces inclined outward in the vertical direction. In other words, the switching valve 68 is a shape that protrudes outward in the vertical direction, and the thickness gradually decreases radially from the outer side of the front end protruding in the vertical direction. The protruding end faces of the switching valve 68 in the vertical direction are arc-shaped curved surfaces. The upper front end of the switching valve 68 is inserted into the first flow path forming hole 52, and the lower front end is inserted into the second flow path forming hole 56.

[0057] The inner circumferential side of the switching valve 68 is integrally connected to the clamping portion 64 via a thin-walled portion 70. The vertical thickness of the thin-walled portion 70 is thinner than the thickness of the inner circumferential end of the switching valve 68, preferably less than half the thickness relative to the inner circumferential end of the switching valve 68. The radial width of the thin-walled portion 70 is smaller than the radial width of the switching valve 68. The clamping portion 64 and the switching valve 68 are connected via the thin-walled portion 70, thereby allowing the switching valve 68 to tilt relative to the clamping portion 64 in a rocking motion relative to both the upper and lower sides by deformation of the thin-walled portion 70, enabling the switching valve 68 to tilt about its base end.

[0058] A fin-like protrusion 72 protrudes from the outer peripheral surface of the switching valve 68. For example... Figure 4 As shown, the fin-shaped protrusion 72 is formed as a thin-walled membrane that is continuous throughout the entire circumference and protrudes outward from the switching valve 68 throughout the entire circumference. The fin-shaped protrusion 72 is integrally formed with the switching valve 68 and is elastically deformable. The fin-shaped protrusion 72 protrudes from the middle portion of the front end of the switching valve 68 that is offset from both sides in the vertical direction, and more preferably from the central portion in the vertical direction. The outer peripheral end of the fin-shaped protrusion 72, which is the protruding front end, has a thick-walled front end 74 with a wall thickness thicker than the protruding base end. The thick-walled front end 74 is formed into a generally circular cross section in the longitudinal section. By providing the thick-walled front end 74, the spring constant of the thin-walled portion on the inner peripheral side of the thick-walled front end 74 can be reduced, and the prevention of poor forming and the assurance of deformation rigidity are achieved in the thick-walled front end 74.

[0059] A groove-shaped portion 76, which opens on the outer peripheral surface and extends vertically, is provided at the outer peripheral end of the fin-shaped protrusion 72. There may be only one groove-shaped portion 76, but it is preferable to have multiple groove-shaped portions 76 in the circumferential direction, for example, multiple groove-shaped portions 76 are provided at approximately equal intervals in the circumferential direction. The groove-shaped portion 76 is preferably provided at the thick-walled front end 74, thereby stabilizing the cross-sectional shape.

[0060] With the elastic movable body 62 disposed in the receiving space 60, the switching valve 68 is located on the extension line of the first flow path forming hole 52 and the second flow path forming hole 56. With the elastic movable body 62 disposed in the receiving space 60, the outer peripheral surface of the switching valve 68 is positioned in a close-proximity state with the outer peripheral walls of the first flow path forming hole 52 and the second flow path forming hole 56 in a completely separated manner.

[0061] A recess 78 is provided at a position on the outer periphery of the first flow path forming hole 52 and the second flow path forming hole 56. The recess 78 opens on another wall surface of the fluid passage 92, namely the outer peripheral wall surface 96, which will be described later, and the outer peripheral wall surface of the recess 78 constitutes part of the outer peripheral wall surface 96. The recess 78 is provided continuously throughout the entire circumference and opens towards the inner periphery. In this embodiment, the recess 78 is formed by utilizing the outer peripheral end of the first partition plate 42 that accommodates the recess 48, and is provided between the overlapping surfaces of the first partition plate 42 and the second partition plate 44.

[0062] With the elastic movable body 62 positioned in the receiving space 60, the fin-shaped protrusion 72 enters the recess 78. The upper and lower surfaces of the fin-shaped protrusion 72 separate from the upper and lower walls of the recess 78. The thick-walled front end 74 of the fin-shaped protrusion 72, serving as its outer peripheral end, contacts the outer peripheral wall of the recess 78. The portion of the fin-shaped protrusion 72 that forms a groove-shaped portion 76 opening towards the outer peripheral surface separates from the outer peripheral wall (outer peripheral wall 96) of the recess 78; the portion forming the groove-shaped portion 76 is the portion approaching the outer peripheral wall 96.

[0063] The partition member 40, configured in this way, is disposed in the fluid sealing region 38. The partition member 40 extends vertically along the axis within the fluid sealing region 38, and its outer peripheral surface is pressed against the small-diameter cylindrical portion 28 of the second mounting member 14 via the sealing rubber layer 32. The outer peripheral end is axially clamped and positioned between the main rubber elastomer 16 and the fixing member 36.

[0064] The fluid-sealing region 38 is divided into two parts by the dividing member 40. At the upper part of the dividing member 40, a portion of the wall is composed of a main rubber elastomer 16, forming a pressure chamber 80 that serves as the main liquid chamber, causing internal pressure variations upon vibration input. At the lower part of the dividing member 40, a portion of the wall is composed of a flexible membrane 34, forming a balance chamber 82 that allows for volume changes. Incompressible fluid is sealed in both the pressure chamber 80 and the balance chamber 82.

[0065] The opening of the circumferential groove 58 provided in the partition member 40 is covered by the second mounting member 14 to which the sealing rubber layer 32 is fixed, forming a tunnel-like flow path extending circumferentially. One end of this tunnel-like flow path communicates with the pressure chamber 80 through the first connecting port 84, and the other end communicates with the balance chamber 82 through the second connecting port 86. The throttling flow path 88, which connects the pressure chamber 80 and the balance chamber 82, is configured to include the circumferential groove 58. The throttling flow path 88 is tuned, for example, to low-frequency, large-amplitude vibrations such as engine vibration.

[0066] The first overflow hole 50, which penetrates the upper side wall of the receiving space 60 formed by the first partition plate 42, communicates with the pressure chamber 80 through its upper opening at one of its three circumferential openings. The second overflow hole 54, which penetrates the lower side wall of the receiving space 60 formed by the second partition plate 44, communicates with the balance chamber 82 through its lower opening at one of its three circumferential openings. Thus, the overflow passage 90, which penetrates the partition member 40 and connects the pressure chamber 80 and the balance chamber 82, is configured to include the first overflow hole 50 and the second overflow hole 54.

[0067] The overflow valve 66 of the elastic movable body 62 is positioned midway along the fluid flow direction (flow path length direction) of the overflow passage 90, and the overflow valve 66 is pressed against the inner circumferential wall of the overflow passage 90. As a result, the overflow passage 90 is shut off by the overflow valve 66.

[0068] A first flow path forming hole 52, penetrating the upper side wall of the receiving space 60 formed by the first partition plate 42, communicates with the pressure chamber 80 at the upper opening of its three circumferential openings. A second flow path forming hole 56, penetrating the lower side wall of the receiving space 60 formed by the second partition plate 44, communicates with the balance chamber 82 at the lower opening of its three circumferential openings. Thus, the fluid passage 92, which penetrates the partition member 40 and connects the pressure chamber 80 and the balance chamber 82, is configured to include the first flow path forming hole 52 and the second flow path forming hole 56. The fluid passage 92 is tuned, for example, for mid-frequency, mid-amplitude vibrations such as idling vibration. In the fluid passage 92, one wall surface orthogonal to the length direction of the flow path is the inner circumferential wall surface 94, and the other wall surface is the outer circumferential wall surface 96.

[0069] The switching valve 68 of the elastic movable body 62 is disposed inside the fluid passage 92. The switching valve 68 protrudes from the inner peripheral side wall 94 of the fluid passage 92 toward the outer peripheral side wall 96. Gap 98 is formed between the outer peripheral surface of the switching valve 68 and the outer peripheral side wall 96 of the fluid passage 92, and the switching valve 68 is disposed in a close-to-close configuration relative to the outer peripheral side wall 96 of the fluid passage 92. Moreover, a leakage passage 100 is formed by the opposition between the outer peripheral surface of the switching valve 68 and the outer peripheral side wall 96 of the fluid passage 92, the vertical opposition between the fin-shaped protrusion 72 and the recess 78, and the groove 76, which connects the upper and lower sides of the switching valve 68. The leakage passage 100 extends between the thick-walled front end 74 of the fin-shaped protrusion 72 and the outer peripheral side wall of the recess 78, which is part of the outer peripheral side wall 96 of the fluid passage 92, and communicates with the pressure chamber 80 and the balance chamber 82 via the fluid passage 92. The leakage path 100 is tuned, for example, to micro-amplitude vibrations equivalent to vibrations during driving.

[0070] The engine mount 10, configured in this way, is mounted on a vehicle, for example, by mounting a first mounting member 12 to a power unit (not shown) and a second mounting member 14 to a vehicle body (not shown). The first mounting member 12 may also be mounted to the power unit via an inner bracket (not shown). The second mounting member 14 may also be mounted to the vehicle body via an outer bracket (not shown).

[0071] When the vehicle is assembled, when a low-frequency, large-amplitude vibration equivalent to engine vibration is input, a relative pressure change is caused between the pressure chamber 80 and the balance chamber 82. The fluid flow through the throttling passage 88 is actively generated in a resonant state, exerting a vibration damping effect (vibration attenuation) based on the fluid flow.

[0072] When low-frequency, large-amplitude vibration is input, the fluid passage 92 and the leakage passage 100 are cut off by the switching valve 68 of the elastic movable body 62. That is, as Figure 5 As shown, the switching valve 68 tilts in a head-shaking motion around the thin-walled portion 70 as its pivot point. The upper and lower ends of the switching valve 68 abut against the outer peripheral wall 96 of the fluid passage 92, thereby cutting off the fluid passage 92 and the leakage passage 100. This prevents the relative pressure fluctuation between the pressure chamber 80 and the balance chamber 82 from being reduced due to fluid flow through the fluid passage 92 and the leakage passage 100, thus effectively generating fluid flow through the throttling path 88 and effectively achieving a vibration-damping effect based on the throttling path 88. In this way, the switching mechanism, by abutting the switching valve 68 against the outer peripheral wall 96 of the fluid passage 92 and closing the gap 98, cuts off the fluid passage 92 and the leakage passage 100.

[0073] Because the switching valve 68 protrudes outward from the clamping part 64, it is easy for the switching valve 68 to undergo elastic deformation. Since the upper and lower front ends of the switching valve 68, which abut against the outer peripheral sidewall 96 of the fluid passage 92, have a smaller radial thickness, impact noise is reduced when the switching valve 68 abuts against the outer peripheral sidewall 96 of the fluid passage 92 in a generally radial direction due to its swaying displacement. The front ends (upper and lower ends) of the switching valve 68 are shaped to extend upward and downward, and fin-shaped protrusions 72 protrude from the middle portion of the switching valve 68. Therefore, the switching valve 68 can abut against the outer peripheral sidewall 96 of the fluid passage 92 on both the upper and lower sides of the recess 78 while the fin-shaped protrusions 72 are inserted into the recess 78.

[0074] When an input vibration of medium frequency and medium amplitude, such as idling vibration, is received, a vibration damping effect with low dynamic spring characteristics can be achieved, for example, based on the fluid flow or liquid column resonance effect of the fluid passage 92, which is essentially maintained in a connected state. That is, when the input vibration is a medium amplitude vibration, the swaying displacement of the switching valve 68 occurs within a range that does not reach the contact of the outer peripheral sidewall 96, thus allowing fluid to pass through the fluid passage 92 along with the swaying displacement of the switching valve 68. Therefore, based on the tuning of this fluid passage 92, for example, low dynamic spring characteristics against idling vibration can be achieved.

[0075] On the other hand, when micro-amplitude vibrations are input in the low-frequency, mid-frequency, or high-frequency bands, such as vibrations during driving, the micro-amplitude vibrations deviate from the tuning frequency of the fluid passage 92 and / or make it difficult to ensure an effective fluid flow rate. Even if the fluid flow based on the swaying displacement of the switching valve 68 is suppressed, such as... Figure 6 As shown, the gaps 98, 98 between the opposing surfaces of the switching valve 68 and the outer peripheral sidewall 96 of the fluid passage 92 can also be maintained, making the leakage passage 100 including the groove 76 connected. Therefore, fluid flow through the leakage passage 100 including the groove 76 is allowed, thus preventing the pressure chamber 80 from becoming sealed. Pressure fluctuations in the pressure chamber 80 are reduced or eliminated by releasing them to the balance chamber 82, thereby achieving the vibration damping effect (vibration insulation effect) brought about by the low-frequency spring. Furthermore, the throttling passage 88 tuned to a low frequency is substantially cut off due to anti-resonance when a vibration input at a higher frequency than the tuning frequency is received.

[0076] Since the switching valve 68 protrudes outward from the clamping portion 64, and the leakage passage 100 is located on the outer periphery of the fluid passage 92, the circumferential length of the leakage passage 100 can be increased. Therefore, for example, it is possible to reduce the distance (radial width of gaps 98, 98) between the opposing surfaces of the switching valve 68 and the fluid passage 92 while ensuring the cross-sectional area of ​​the leakage passage 100. As a result, for example, it becomes easier to ensure low dynamic spring action characteristics when there is fluid flow through the leakage passage 100 or input of micro-amplitude vibrations, and to appropriately set the switching threshold of the switching valve 68 for the fluid passage 92.

[0077] In the formation of the groove 76, the fin-shaped protrusions 72 are separated from the outer peripheral wall of the recess 78 in a close proximity state. Therefore, the leakage passage 100 including the groove 76 will not be accidentally cut off, and the vibration damping effect based on the leakage passage 100 can be stably exerted.

[0078] The groove-shaped portion 76 constituting the leakage passage 100 is formed at the thick-walled front end portion 74 of the fin-shaped protrusion 72, which has relatively high deformation rigidity. As a result, changes in the cross-sectional shape of the groove-shaped portion 76 are suppressed, and the cross-sectional area of ​​the leakage passage 100 is stabilized.

[0079] Furthermore, on the other hand, when small-amplitude vibrations (larger than micro-amplitude) are input, such as as a rumbling sound during driving, in a predetermined frequency band in the low, mid, or high frequency band, the fluid flow based on the swaying displacement of the switching valve 68 is suppressed by deviating the tuning frequency of the fluid passage 92 and / or by using small amplitude vibrations that make it difficult to ensure an effective fluid flow rate. Moreover, by deviating the tuning frequency of the leakage passage 100 and / or by the fluid flow rate through the leakage passage 100 including the groove 76, the pressure fluctuations in the pressure chamber 80 are not eliminated. Therefore, as... Figure 7 As shown, the relative pressure variation between the pressure chamber 80 and the balance chamber 82 acts on both sides of the fin-shaped protrusion 72, causing elastic deformation. Accompanying the elastic deformation of the fin-shaped protrusion 72, fluid flows through the gaps 98, 98. Utilizing this fluid flow effect, such as the fluid flow effect of liquid column resonance, it is possible to achieve vibration damping characteristics such as high attenuation and low dynamic spring action when small amplitude vibrations of a predetermined frequency band are input.

[0080] In this embodiment, since the front end of the fin-shaped protrusion 72 (thick-walled front end 74) abuts against the outer peripheral wall of the recess 78, the fin-shaped protrusion 72 undergoes a deformation similar to that of a double-support beam, with the largest deformation in the radial middle portion (see reference). Figure 7However, the deformation mode of the fin-shaped protrusion 72 is not particularly limited. For example, when the front end of the fin-shaped protrusion 72 separates from the outer peripheral wall of the recess 78, the fin-shaped protrusion 72 will produce a cantilever beam-like deformation with the largest deformation at the front end.

[0081] Furthermore, when small-amplitude vibrations are input, the head-shaking displacement and vertical parallel displacement of the switching valve 68 caused by the deformation of the thin-walled portion 70 cannot keep up with the amplitude and / or frequency of the input vibration. This prevents the leakage of hydraulic pressure through the fluid passage 92 due to the minute displacement of the switching valve 68. Therefore, the hydraulic pressure fluctuation acting on the fin-shaped protrusion 72 increases, effectively utilizing the vibration damping effect based on the elastic deformation of the fin-shaped protrusion 72.

[0082] The fin-shaped protrusions 72 are arranged all around the circumference, and the circumferential length is increased. Therefore, it is not necessary to increase the diameter of the partition member 40, and the amount of fluid flow accompanying the deformation of the fin-shaped protrusions 72 can be ensured to obtain a greater vibration damping effect, and the tuning freedom of the natural vibration frequency of the fin-shaped protrusions 72 can be obtained to a greater extent.

[0083] Since the fin-shaped protrusion 72 is inserted into the recess 78 that opens in the outer peripheral sidewall 96 of the fluid passage 92, it is not necessary to increase the diameter of the separating member 40, and the protruding length dimension (radial width dimension) of the fin-shaped protrusion 72 can be increased. Therefore, the fluid flow rate associated with the deformation of the fin-shaped protrusion 72 can be ensured, the vibration damping effect based on the deformation of the fin-shaped protrusion 72 can be maximized, and the resonant frequency of the deformation of the fin-shaped protrusion 72 can be set with a large degree of freedom.

[0084] The fin-shaped protrusion 72 is disposed in the middle portion of the switching valve 68 in the vertical direction, and the middle portion of the switching valve 68 is formed to be thicker in the radial direction compared with the upper and lower end portions. Therefore, compared with the case where the fin-shaped protrusion 72 protrudes from the upper and lower end portions which are set to be thin-walled, the deformation of the switching valve 68 is less likely to occur when the fin-shaped protrusion 72 is deformed due to hydraulic pressure, and the deformation of the fin-shaped protrusion 72 is effectively generated.

[0085] Furthermore, in cases where the internal pressure of the pressure chamber 80 drops significantly due to input impact loads, the fluid flow via the overflow passage 90 prevents cavitation noise. Specifically, the overflow valve 66 deforms due to the pressure difference between the internal pressure of the pressure chamber 80 acting on the upper surface of the overflow valve 66 and the internal pressure of the balance chamber 82 acting on the lower surface of the overflow valve 66, causing the overflow valve 66 to separate from the inner circumferential wall of the overflow passage 90. The shut-off of the overflow valve 66 in the overflow passage 90 is released, and the overflow passage 90 becomes open. Fluid flows from the balance chamber 82 to the pressure chamber 80 through the overflow passage 90, thereby rapidly reducing or eliminating the negative pressure in the pressure chamber 80 and preventing cavitation caused by a sudden pressure drop.

[0086] In addition to the vibration damping characteristics for low-frequency large-amplitude vibrations achieved by the throttling flow path 88, the vibration damping characteristics for mid-frequency medium-amplitude vibrations achieved by the fluid passage 92, the vibration damping characteristics for micro-amplitude vibrations achieved by the leakage passage 100 including the groove-shaped portion 76, and the vibration damping characteristics for small-amplitude vibrations achieved by the elastic deformation of the fin-shaped protrusion 72, for micro-amplitude or small-amplitude vibrations in higher frequency bands such as high-speed roaring sounds, for example, by the action of the switching valve 68 itself like a movable diaphragm, it is also possible to avoid or reduce the significant high-dynamic springing caused by the anti-resonance effect of each passage such as the throttling flow path 88, the fluid passage 92, the leakage passage 100, etc., becoming a substantial cut-off state due to the anti-resonance effect of the fluid. That is, since the switching valve 68 has a thin-walled portion 70 at its base that is thin-walled and easily deformable, the switching valve 68 can be slightly displaced in the vertical direction (fluid flow direction) by utilizing the relative pressure change between the pressure chamber 80 and the balance chamber 82 that accompanies the up-and-down movement of the switching valve 68. This pressure change in the pressure chamber 80 can also reduce the high-dynamic springing effect. Generally, the vibrations of objects that cause problems, such as high-speed roaring sounds, are significantly higher in frequency than the vibrations described above, namely, the vibration damping characteristics for low-frequency large-amplitude vibrations achieved by the throttling path 88, the vibration damping characteristics for mid-frequency medium-amplitude vibrations achieved by the fluid passage 92, the vibration damping characteristics for micro-amplitude vibrations achieved by the leakage passage 100 including the groove-shaped portion 76, and the vibration damping characteristics for small-amplitude vibrations achieved by the elastic deformation of the fin-shaped protrusion 72. The amplitude is also usually much smaller. Therefore, the action of the movable diaphragm of the switching valve 68 can be used without causing significant adverse effects on the vibration damping characteristics achieved by these devices.

[0087] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific descriptions thereto. For example, the switching valve 68 may protrude from the clamping portion 64 toward the inner periphery, and the fin-shaped protrusion 72 may be provided in such a way that it further protrudes from the switching valve 68 toward the inner periphery. In addition, the overflow valve 66 is not necessary; for example, an elastic movable body composed of the clamping portion 64, the switching valve 68, and the fin-shaped protrusion 72 may be used. Furthermore, as a movable membrane capable of elastically deforming the inner periphery of the clamping portion 64 in the thickness direction, a new device may be constructed that functions as a low-motion spring based on the elastic deformation of the relative pressure variation between the pressure chamber 80 and the balance chamber 82 acting on the upper and lower surfaces of the movable membrane, thereby reducing pressure variation in the pressure chamber 80 during a predetermined vibration input.

[0088] Preferably, the front end of the fin-shaped protrusion 72 is thick-walled, but a thick-walled front end 74 is not necessary. Furthermore, the thickness of the fin-shaped protrusion 72 does not need to be constant outside the front end; thin-walled and thick-walled portions are permissible. Additionally, the switching valve 68 and the fin-shaped protrusion 72 do not need to be formed throughout the entire circumference of the elastic movable body 62; they can be formed locally in the circumferential direction. Alternatively, instead of an annular fluid passage 92, a fluid passage with a predetermined cross-sectional shape, such as a rectangular cross-section, can be used to penetrate vertically along the dividing member 40, and a switching valve protruding from one wall towards the other wall can be used within this fluid passage.

[0089] The groove-shaped portion 76 is not necessary, and the fin-shaped protrusions 72 can also abut against the wall on the other side of the fluid passage 92 throughout its entire circumference. In this case, for example, the fin-shaped protrusions 72 deform and move away from the wall on the other side of the fluid passage 92, thereby forming a leakage passage 100. The fin-shaped protrusions 72 can also be distributed around the wall on the other side of the fluid passage 92 away from its entire circumference.

[0090] For example, the protruding length of the fin-shaped protrusion 72 can be increased by forming an opening in the recess on the outer peripheral surface of the switching valve 68 and providing a structure in which the fin-shaped protrusion 72 protrudes from the bottom surface of the recess.

[0091] Furthermore, in this invention, throttling path 88, overflow path 90, etc., are not essential and do not necessarily need to be provided.

[0092] Explanation of reference numerals in the attached figures

[0093] 10: Engine mount (fluid-sealed vibration damping device);

[0094] 12: First mounting component;

[0095] 14: Second mounting component;

[0096] 16: Main body rubber elastomer;

[0097] 18: Fixed components;

[0098] 20: Through hole;

[0099] 22: Mounting bolts;

[0100] 24: Step section;

[0101] 26: Large diameter cylinder;

[0102] 28: Small-diameter cylindrical section;

[0103] 30: Large diameter recess;

[0104] 32: Sealing rubber layer;

[0105] 34: Flexible membrane;

[0106] 36: Fixed components;

[0107] 38: Fluid enclosed area;

[0108] 40: Separating components;

[0109] 42: First partition plate;

[0110] 44: Second partition;

[0111] 45: Fitting recess;

[0112] 46: Incision-like portion;

[0113] 48: To accommodate a recessed area;

[0114] 50: First overflow hole;

[0115] 52: First flow path forming hole;

[0116] 53: Fitting convex part;

[0117] 54: Second overflow hole;

[0118] 56: Second flow path forming hole;

[0119] 58: Zhou Cao;

[0120] 60: Accommodation space;

[0121] 62: Elastic movable body (rubber membrane);

[0122] 64: Clamping part;

[0123] 66: Overflow valve;

[0124] 68: Switching valve;

[0125] 70: Thin-walled portion;

[0126] 72: Wing-like projections;

[0127] 74: Thick-walled front end;

[0128] 76: Groove-shaped part;

[0129] 78: Recessed area;

[0130] 80: Pressure chamber (main liquid chamber);

[0131] 82: Balance chamber (auxiliary liquid chamber);

[0132] 84: First connecting port;

[0133] 86: Second connecting port;

[0134] 88: Streamline traffic flow;

[0135] 90: Overflow path;

[0136] 92: Fluid pathway;

[0137] 94: Inner peripheral side wall surface (wall surface of one side);

[0138] 96: Outer peripheral sidewall (the other side of the wall);

[0139] 98: Gap;

[0140] 100: Leakage path.

Claims

1. A fluid-sealed vibration damping device (10) having a structure in which a main liquid chamber (80) and a secondary liquid chamber (82) containing fluid are separated by a separating member (40), wherein, The fluid-sealed vibration damping device (10) has a fluid passage (92) that passes through the partition member (40) and communicates with the main liquid chamber (80) and the auxiliary liquid chamber (82). Inside the fluid passage (92), a switching valve (68) is disposed protruding from one wall surface (94) of the fluid passage (92) toward the other wall surface (96), and a gap (98) is provided between the switching valve (68) and the other wall surface (96). The switching valve (68) is configured to tilt at its base end. The tilting displacement of the switching valve (68) in the direction of the passage length of the fluid passage (92) causes the front end of the switching valve (68) to abut against the wall (96) on the other side of the fluid passage (92), thereby forming a switching mechanism that closes the gap (98). The fluid-sealed vibration damping device (10) is provided with an elastically deformable fin-shaped protrusion (72) that can protrude from the front end of the switching valve (68) to the other wall (96) of the fluid passage (92), and a leakage passage (100) is formed between the protruding front end of the fin-shaped protrusion (72) and the other wall (96). The front end of the fin-shaped protrusion (72) has a thick-walled front end (74) that is thicker than the base end of the fin-shaped protrusion (72) in the passage length direction of the fluid passage (92).

2. The fluid-sealed vibration damping device (10) according to claim 1, wherein, A recess (78) is provided on the other wall (96) of the fluid passage (92), into which the fin-shaped protrusion (72) enters.

3. The fluid-sealed vibration damping device (10) according to claim 1 or 2, wherein, The fluid-sealed vibration damping device (10) is provided with a rubber membrane (62) held by the separating member (40). The switching valve (68) protrudes from the clamping portion of the rubber diaphragm (62) toward the other wall (96) of the fluid passage (92) and extends circumferentially.

4. The fluid-sealed vibration damping device (10) according to claim 3, wherein, The switching valve (68) is provided protruding from the clamping portion of the rubber diaphragm (62) all around the circumference, and the fin-shaped protrusion (72) is provided protruding from the outer circumference of the switching valve (68).

5. The fluid-sealed vibration damping device (10) according to claim 1 or 2, wherein, The front end of the fin-shaped protrusion (72) is formed as a proximity portion that is at least a portion circumferentially separated from the wall (96) of the other side of the fluid passage (92), through which the leakage passage (100) is formed.

6. The fluid-sealed vibration damping device (10) according to claim 1 or 2, wherein, The fin-shaped protrusion (72) abuts against the other wall (96) of the fluid passage (92) all around the circumference, and the fin-shaped protrusion (72) separates from the other wall (96) due to elastic deformation to form the leakage passage (100).

7. The fluid-sealed vibration damping device (10) according to claim 1 or 2, wherein, The front end of the switching valve (68) is shaped to extend to both sides in the length direction of the fluid passage (92). The fin-shaped protrusion (72) protrudes from the middle portion of the front end of the switching valve (68) in the direction of the passage length of the fluid passage (92).

8. The fluid-sealed vibration damping device (10) according to claim 1 or 2, wherein, The fluid-sealed vibration damping device (10) is provided with a throttling passage (88) that connects the main liquid chamber (80) and the auxiliary liquid chamber (82) to each other. The resonant frequency of fluid flow through the sectional flow path (88) is set to a frequency lower than the resonant frequency of fluid flow through the fluid passage (92).

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