Liquid-filled anti-vibration device

Abstract

Provided is a liquid-filled anti-vibration device capable of improving the durability of a valve part. The plate portion (41) of the switching film (40) is sandwiched between the first partition plate (23) and the second partition plate (26). A pair of cylindrical valve sections (42, 43) protrude from the entire periphery of the outer peripheral edge (41c) of the plate section (41) toward both sides of the plate section (41) in the plate thickness direction. On the outer peripheral surface of the switching film (40), inclined surfaces (42a, 43a) inclined radially inward toward the center of the plate part (41) in the plate thickness direction are formed at positions including the outer peripheral edge (41c) of the plate part (41). Through the inclined surfaces (42a) and (43a), one of the pair of valve parts (42) and (43) can easily incline outwards in the radial direction independently from the other valve part. Therefore, when one of the valve parts (42, 43) cuts off the orifice, deformation of the other of the valve parts (42, 43) can be suppressed, and durability of the valve parts (42, 43) can be improved.

Description

Technical Field

[0001] The present invention relates to a liquid-filled vibration isolation device, and more particularly to a liquid-filled vibration isolation device capable of improving the durability of a valve portion. Background Art

[0002] As a vibration isolation device for supporting a vibration source such as an engine on a vehicle body (support side), for example, a liquid-filled vibration isolation device disclosed in Patent Document 1 is known. In the liquid-filled vibration isolation device disclosed in Patent Document 1, a liquid chamber formed inside is partitioned into a first liquid chamber and a second liquid chamber by a partition, and the first liquid chamber and the second liquid chamber communicate with each other through a throttle hole. The partition includes: a first partition plate facing the first liquid chamber; a second partition plate facing the second liquid chamber; and a switching valve that switches the communication state and the cut-off state of the throttle hole.

[0003] The switching valve of Patent Document 1 includes an annular support portion sandwiched between the first partition plate and the second partition plate, and a pair of annular (tubular) valve portions protruding from the support portion toward both sides in the axial direction. The communication state separated from the inner wall of the throttle hole is switched to the cut-off state by the liquid flow in the throttle hole causing the entire valve portion to tilt and contact the inner wall of the throttle hole.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-102168 Summary of the Invention

[0007] (I) Technical Problems to be Solved

[0008] However, in the above Patent Document 1, when switching the throttle hole from the communication state to the cut-off state, one of the pair of valve portions contacts the inner wall of the throttle hole, but the other deforms away from the inner wall and does not contribute to the cut-off of the throttle hole. Due to the deformation of the other valve portion, the durability of the valve portion may be reduced.

[0009] The present invention has been made to solve the above problems, and an object thereof is to provide a liquid-filled vibration isolation device capable of improving the durability of a valve portion.

[0010] (II) Technical Solutions

[0011] To achieve this object, a liquid-filled vibration isolator according to a first aspect of the present invention includes: a first member and a cylindrical second member; a vibration isolation base body made of an elastic body that connects the first member and the second member; a diaphragm made of an elastic body that is attached to the second member and forms a liquid chamber filled with a liquid between the diaphragm and the vibration isolation base body; a partition that divides the liquid chamber into a first liquid chamber and a second liquid chamber; a throttle hole that is formed in the partition and connects the first liquid chamber and the second liquid chamber; and a switching film made of an elastic body that switches the connection state and the cut-off state of the throttle hole. The partition includes a first partition plate facing the first liquid chamber and a second partition plate facing the second liquid chamber. The throttle hole is formed by an annular accommodation space formed between the first partition plate and the second partition plate, a plurality of first through holes formed through the first partition plate to connect the first liquid chamber and the accommodation space, and a plurality of second through holes formed through the second partition plate to connect the second liquid chamber and the accommodation space. The switching film includes: a plate portion having an outer peripheral edge that is radially opposed to the outer peripheral wall surface of the accommodation space over the entire circumference and is sandwiched between the first partition plate and the second partition plate so that the outer peripheral edge protrudes into the accommodation space; and a pair of cylindrical valve portions that protrude from the entire circumference of the outer peripheral edge of the plate portion toward both sides in the plate thickness direction of the plate portion. In the connected state, a gap is formed between the valve portion and the outer peripheral wall surface. In the cut-off state, the throttle hole is cut off by the valve portion that deforms radially outward and contacts the outer peripheral wall surface. On the outer peripheral surface of the switching film including the outer peripheral edge and the outer peripheral surface of the valve portion, an inclined surface that inclines radially inward toward the center in the plate thickness direction of the plate portion is formed at least at a position including the outer peripheral edge.

[0012] In addition, the liquid-filled vibration isolator according to the eighth aspect of the present invention includes: a first member and a cylindrical second member; a vibration isolation base body made of an elastic body, which connects the first member and the second member; a diaphragm made of an elastic body, which is installed on the second member and forms a liquid chamber filled with liquid between the vibration isolation base body; a partition body, which divides the liquid chamber into a first liquid chamber and a second liquid chamber; a throttle hole, which is formed in the partition body and communicates the first liquid chamber and the second liquid chamber; and a switching film made of an elastic body, which switches the communication state and the cut-off state of the throttle hole. The partition body includes a first partition plate facing the first liquid chamber and a second partition plate facing the second liquid chamber. The throttle hole is formed by an annular accommodation space formed between the first partition plate and the second partition plate, a plurality of first through holes formed through the first partition plate and communicating the first liquid chamber and the accommodation space, and a plurality of second through holes formed through the second partition plate and communicating the second liquid chamber and the accommodation space. The switching film includes: an annular plate portion, which has an inner peripheral edge that is radially opposed to the inner peripheral wall surface of the accommodation space throughout the entire circumference, and is sandwiched between the first partition plate and the second partition plate in such a manner that the inner peripheral edge projects into the accommodation space; and a pair of cylindrical valve portions, which project from the entire circumference of the inner peripheral edge of the plate portion toward both sides in the plate thickness direction of the plate portion. In the communication state, a space is formed between the valve portion and the inner peripheral wall surface. In the cut-off state, the throttle hole is cut off by the valve portion deformed radially inward and contacting the inner peripheral wall surface. On the inner peripheral surface of the switching film including the inner peripheral edge and the inner peripheral surface of the valve portion, an inclined surface that inclines radially outward toward the center in the plate thickness direction of the plate portion is formed at least at a position including the inner peripheral edge.

[0013] (III) Beneficial effects

[0014] In the liquid-filled vibration isolator according to the first aspect, the plate portion of the switching film is sandwiched between the first partition plate and the second partition plate in such a manner that it projects into a part of the accommodation space forming the throttle hole. The outer peripheral edge of the plate portion is radially opposed to the outer peripheral wall surface of the accommodation space throughout the entire circumference. A pair of cylindrical valve portions project from the entire circumference of the outer peripheral edge of the plate portion toward both sides in the plate thickness direction of the plate portion. The switching film is a component that switches between a communication state in which a space is formed between the valve portion and the outer peripheral wall surface, and a cut-off state in which the throttle hole is cut off by the valve portion deformed radially outward (tilted) and contacting the outer peripheral wall surface. The deformation radially outward is generated by the flow of liquid in the throttle hole.

[0015] On the outer peripheral surface of a switching film including the outer peripheral edge of a plate portion and the outer peripheral surface of a valve portion, an inclined surface that inclines radially inward toward the center in the plate thickness direction of the plate portion is formed at least at a position including the outer peripheral edge. By this inclined surface, it is possible to easily cause one of a pair of valve portions to fall radially outward independently of the other. Therefore, when one of the valve portions cuts off a throttle hole, deformation of the other valve portion can be suppressed, and thus the durability of the valve portion can be improved.

[0016] The liquid-filled vibration isolator according to the second aspect, in addition to the effects achieved by the liquid-filled vibration isolator according to the first aspect, achieves the following effects. The outer peripheral surface of the valve portion is formed by an inclined surface, and the inner peripheral surface of the valve portion inclines along the inclined surface. Thereby, the thickness of the valve portion can be made to approach substantially constant, and thus, when the valve portion falls, deformation concentration in a thin portion of the valve portion can be suppressed. As a result, the durability of the valve portion can be further improved.

[0017] The liquid-filled vibration isolator according to the third aspect, in addition to the effects achieved by the liquid-filled vibration isolator according to the second aspect, achieves the following effects. A concave portion that is recessed radially inward is formed on the outer peripheral edge side of the inclined surface. Since the valve portion becomes easy to fall with this concave portion as a fulcrum, it becomes difficult for a pair of valve portions to deform integrally. As a result, the durability of the valve portion can be further improved.

[0018] The liquid-filled vibration isolator according to the fourth aspect, in addition to the effects achieved by the liquid-filled vibration isolator according to the third aspect, achieves the following effects. A convex portion that bulges radially inward toward the radially opposite side of the concave portion is provided on the inner peripheral surface of the valve portion. Thereby, even when the concave portion is provided, the thickness of the valve portion can be made to approach substantially constant by the convex portion. As a result, when the valve portion deforms, deformation concentration near the concave portion can be suppressed and the durability of the valve portion can be prevented from decreasing.

[0019] The liquid-filled vibration isolator according to the fifth aspect, in addition to the effects achieved by the liquid-filled vibration isolator according to the third aspect, achieves the following effects. The concave portion extends across the outer peripheral surface of the valve portion and the outer peripheral edge of the plate portion. Thereby, the valve portion becomes easy to fall from the root, and thus, compared with the case where the valve portion is bent halfway, the time from the start of falling of the valve portion to contact with the outer peripheral wall surface can be shortened. As a result, the switching sensitivity of the throttle hole from the communication state to the cut-off state can be improved.

[0020] The liquid-filled vibration isolator according to the sixth aspect, in addition to the effects achieved by the liquid-filled vibration isolator of the second aspect, achieves the following effects. The first through-hole and the second through-hole open into the accommodation space at positions radially opposed to the inner peripheral surface of the valve portion, respectively. The wall surfaces on the plate portion side of the first through-hole and the second through-hole are inclined toward the plate portion side as they face radially outward. As a result, the flow of the liquid flowing out from the first through-hole and the second through-hole into the accommodation space acts substantially perpendicularly on the inner peripheral surface of the valve portion, and thus the valve portion can be brought into contact with the outer peripheral wall surface quickly. As a result, the switching sensitivity of the throttle hole from the communication state to the cut-off state can be improved.

[0021] The liquid-filled vibration isolator according to the seventh aspect, in addition to the effects achieved by any one of the liquid-filled vibration isolators of the first to sixth aspects, achieves the following effects. The shortest distance from the portion of the plate portion sandwiched between the first partition plate and the second partition plate to the valve portion is half or less of the length in the protruding direction of the valve portion. As a result, the displacement of the switching film in the accommodation space in the plate thickness direction as a whole can be suppressed by the liquid flow through the throttle hole, and only the valve portion can be easily tilted.

[0022] The liquid-filled vibration isolator of the eighth aspect is a device in which the configuration and shape of each part are reversed between the inner side and the outer side in the radial direction with respect to the liquid-filled vibration isolator of the first aspect, and thus achieves the same effects as the liquid-filled vibration isolator of the first aspect. Similarly, the liquid-filled vibration isolators of the ninth to fourteenth aspects are devices in which the configuration and shape of each part are reversed between the inner side and the outer side in the radial direction with respect to the liquid-filled vibration isolators of the second to seventh aspects, respectively. Hereinafter, they will be specifically described.

[0023] Regarding the liquid-filled vibration isolator of the ninth aspect, in the liquid-filled vibration isolator of the eighth aspect, the inner peripheral surface of the valve portion is formed by an inclined surface, and the outer peripheral surface of the valve portion is inclined along the inclined surface, and thus achieves the same effects as the liquid-filled vibration isolator of the second aspect.

[0024] Regarding the liquid-filled vibration isolator of the tenth aspect, in the liquid-filled vibration isolator of the ninth aspect, a concave portion recessed radially outward is formed on the inner peripheral edge side of the inclined surface, and thus achieves the same effects as the liquid-filled vibration isolator of the third aspect.

[0025] Regarding the liquid-filled vibration isolator of the eleventh aspect, in the liquid-filled vibration isolator of the tenth aspect, a convex portion that bulges radially outward on the radially opposite side to the concave portion is provided on the outer peripheral surface of the valve portion, and thus achieves the same effects as the liquid-filled vibration isolator of the fourth aspect.

[0026] Regarding the liquid-filled vibration isolator of the twelfth aspect, in the liquid-filled vibration isolator of the tenth aspect, the concave portion is formed across the inner peripheral surface of the valve portion and the inner peripheral edge of the plate portion. Therefore, it has the same effect as the liquid-filled vibration isolator of the fifth aspect.

[0027] Regarding the liquid-filled vibration isolator of the thirteenth aspect, in the liquid-filled vibration isolator of the ninth aspect, the first through-hole and the second through-hole open to the accommodation space at positions radially opposed to the outer peripheral surface of the valve portion, respectively. The wall surfaces on the plate portion side of the first through-hole and the second through-hole are inclined toward the plate portion side as they face radially inward. Therefore, it has the same effect as the liquid-filled vibration isolator of the sixth aspect.

[0028] Regarding the liquid-filled vibration isolator of the fourteenth aspect, in any one of the liquid-filled vibration isolators of the eighth to thirteenth aspects, the shortest distance from the portion of the plate portion sandwiched between the first partition plate and the second partition plate to the valve portion is half or less of the length in the protruding direction of the valve portion. Therefore, it has the same effect as the liquid-filled vibration isolator of the seventh aspect. Description of the Drawings

[0029] Figure 1 is a cross-sectional view of the liquid-filled vibration isolator in the first embodiment.

[0030] Figure 2 is a top view of the separator.

[0031] Figure 3 is a top view of the separator with the first partition plate removed.

[0032] Figure 4 is an enlarged view showing Figure 1 a partial enlarged cross-sectional view of the liquid-filled vibration isolator of the IV portion.

[0033] Figure 5 is a partial enlarged cross-sectional view of the liquid-filled vibration isolator in the second embodiment.

[0034] Figure 6 is a partial enlarged cross-sectional view of the liquid-filled vibration isolator in the third embodiment.

[0035] Figure 7 is a partial enlarged cross-sectional view of the separator of the liquid-filled vibration isolator in the fourth embodiment.

[0036] Description of Reference Numerals:

[0037] 10, 50, 60: Liquid-filled vibration isolator; 11: First component; 12: Second component; 13: Vibration isolation base; 15: Diaphragm; 17: First liquid chamber; 18: Second liquid chamber; 20, 70: Partition; 23, 71: First partition plate; 24c, 71d: First through hole (part of the throttle hole); 26, 73: Second partition plate; 27c, 73f: Second through hole (part of the throttle hole); 29c, 77: Accommodation space (part of the throttle hole); 29d: Outer peripheral wall surface; 40, 61, 80: Switching membrane; 41, 81: Plate part; 41c: Outer periphery; 42, 43, 62, 63, 82, 83: Valve part; 42a, 43a, 64, 65, 82a, 83a: Inclined surface; 42b, 43b, 62b, 63b: Inner peripheral surface of the valve part; 42c, 43c: Concave part; 42d, 43d: Convex part; 51, 52: Wall surface; 62a, 63a, 82b, 83b: Outer peripheral surface of the valve part; 78: Inner peripheral wall surface; 81c: Inner periphery. Detailed implementation mode

[0038] Hereinafter, for the preferred implementation mode, it will be described with reference to the accompanying drawings. Figure 1 It is a cross-sectional view of the liquid-filled vibration isolator 10 in the first implementation mode. In addition, in Figure 1 the no-load state in which no vibration (load) is input to the liquid-filled vibration isolator 10 is shown. Unless otherwise specified, the no-load state will be described for each part of the liquid-filled vibration isolator 10. In addition, in the following description, the upper side of the paper surface of Figure 1 will be described as the upper side of the liquid-filled vibration isolator 10, etc., but the up and down of this liquid-filled vibration isolator 10 do not necessarily coincide with the up and down of the vehicle on which the liquid-filled vibration isolator 10 is installed.

[0039] The liquid-filled vibration isolator 10 is an engine mount that elastically supports the engine of a motor vehicle. The liquid-filled vibration isolator 10 mainly includes: a first component 11 installed on the engine side, which is the vibration source; a cylindrical second component 12 installed on the body side of the support side; and a vibration isolation base 13 composed of an elastic body connecting the first component 11 and the second component 12. In addition, Figure 1 the cross-sectional view of the liquid-filled vibration isolator 10 is an axial cross-sectional view including the axis C of the cylindrical second component 12. The axis C direction is the up and down direction of the liquid-filled vibration isolator 10. Hereinafter, the direction perpendicular to the axis C will be simply referred to as the radial direction, and the direction around the axis C will be simply referred to as the circumferential direction for description.

[0040] The first component 11 is a boss fitting arranged on the axis C in a manner located above the second component 12, and is formed of a metal such as steel or aluminum alloy. A bolt hole is formed on the upper end surface of the first component 11. The first component 11 is installed on the engine side via a bolt installed in the bolt hole.

[0041] The second component 12 is a cylindrical component centered on the axis C, and is mainly formed of metal such as steel. The second component 12 includes: a large diameter portion 12a on the upper end side; a reduced diameter portion 12b connected to the lower end of the large diameter portion 12a and having gradually reduced inner and outer diameters toward the bottom; and a small diameter portion 12c connected to the lower end of the reduced diameter portion 12b and having smaller inner and outer diameters than the large diameter portion 12a. For example, the second component 12 is installed on the vehicle body side by inserting it into a cylindrical bracket provided on the vehicle body side.

[0042] The vibration-proof base 13 is a member made of an elastic material such as rubber or thermoplastic elastomer formed in a roughly umbrella shape. The vibration-proof base 13 is vulcanized and bonded to the lower portion of the first member 11 and the inner peripheral surfaces of the large-diameter portion 12a and the reduced-diameter portion 12b, respectively, and connects them. A rubber film-like membrane portion 14 covering the inner peripheral surface of the small-diameter portion 12c is connected to the lower end of the vibration-proof base 13. The membrane portion 14 is a part of the second member 12.

[0043] The diaphragm 15 is mounted on the second member 12 via the mounting portion 16 so as to close the lower end opening of the small diameter portion 12c. The diaphragm 15 is a membrane made of an elastic material such as rubber. The mounting portion 16 is an annular member made of a metal such as steel. The outer peripheral portion of the diaphragm 15 is vulcanized and bonded to the inner peripheral portion of the mounting portion 16 over the entire circumference.

[0044] The liquid chamber is formed by a closed space divided by the vibration-proof base 13, the second member 12, and the diaphragm 15. An antifreezing liquid such as ethylene glycol (not shown) is sealed in the liquid chamber. The liquid chamber is divided by the partition 20 into a first liquid chamber 17 in which the vibration-proof base 13 constitutes a part of the chamber wall, and a second liquid chamber 18 in which the diaphragm 15 constitutes a part of the chamber wall.

[0045] Furthermore, in order to attach the diaphragm 15 and the separator 20 to the second member 12, first, the separator 20 is inserted into the small diameter portion 12c of the second member 12 until it contacts the step 13a of the vibration-isolating base 13 extending in a stepped manner radially inward from the upper end of the membrane portion 14. Next, after the mounting portion 16 integrated with the diaphragm 15 is inserted into the small diameter portion 12c, the diameter of the small diameter portion 12c (second member 12) is reduced by drawing, and the outer periphery of the separator 20 and the mounting portion 16 is held by the membrane portion 14. Thus, the diaphragm 15 and the separator 20 are attached to the second member 12.

[0046] Apart from Figure 1 In addition, refer to Figures 2 to 4 The separator 20 will be described. Figure 2 is a top view of the separator 20 . Figure 2 The cross section of the separator 20 at line II is shown in Figure 1 middle. Figure 3It is a top view of the separator 20 after removing the first separator plate 23. Figure 4 It is an enlarged view showing Figure 1 a partial enlarged cross-sectional view of the fluid-filled vibration isolator 10 of the IV portion.

[0047] As Figure 1 and Figure 2 shown, the separator 20 includes: a cylindrical member 21 held inside the film portion 14; a flat first separator plate 23 and a second separator plate 26 that vertically divide the inner peripheral side of the cylindrical member 21; and a valve 30 and a switching film 40 disposed between the first separator plate 23 and the second separator plate 26. The first separator plate 23 faces the first liquid chamber 17, and the second separator plate 26 faces the second liquid chamber 18.

[0048] The cylindrical member 21 is a cylindrical part made of metal or synthetic resin. The outer peripheral surface of the cylindrical member 21 is pressed against the small-diameter portion 12c of the second member 12 via the film portion 14 throughout the entire circumference. An outer peripheral groove 22 having a length of approximately two turns is formed on the outer peripheral surface of the cylindrical member 21. A first throttle hole 19 is formed between the outer peripheral groove 22 and the film portion 14.

[0049] One end of the outer peripheral groove 22 opens on the inner peripheral surface of the cylindrical member 21 above the first separator plate 23 or at the upper end of the cylindrical member 21, whereby the first throttle hole 19 communicates with the first liquid chamber 17. The other end of the outer peripheral groove 22 opens on the inner peripheral surface of the cylindrical member 21 below the second separator plate 26 or at the lower end of the cylindrical member 21, whereby the first throttle hole 19 communicates with the second liquid chamber 18.

[0050] In this way, the first throttle hole 19 is a flow path that connects the first liquid chamber 17 and the second liquid chamber 18. For example, in order to attenuate the jitter vibration during vehicle driving, the flow path cross-sectional area, length, cross-sectional perimeter, etc. of the first throttle hole 19 are set so that the attenuation coefficient becomes larger in the frequency band corresponding to the jitter vibration (for example, around 5 to 15 Hz) when a large-amplitude jitter vibration is input.

[0051] The first separator plate 23 is a part made of metal or synthetic resin and is formed in a substantially circular plate shape perpendicular to the axis C. A cylindrical first wall 23a centered on the axis C projects downward (toward the second separator plate 26) from the lower surface of the first separator plate 23.

[0052] In the first separator plate 23, a plurality of holes are formed through in the plate thickness direction (vertical direction) on the radially inner side of the first wall 23a. Among the plurality of holes, there is a central hole 24a provided on the axis C and a plurality of (four in this embodiment) first valve holes 24b provided around the central hole 24a. The plurality of first valve holes 24b are arranged and configured in the circumferential direction.

[0053] The first partition plate 23 includes: a ring-shaped first clamping portion 23b that extends radially outward from the first cylindrical wall 23a; a plurality of (eight in this embodiment) connecting portions 23c that extend radially outward and upward from the outer peripheral edge of the first clamping portion 23b; and an annular outer peripheral portion 23d that is connected to the inner peripheral edge of the connecting portion 23c. An annular protrusion 25 centered on the axis C protrudes from the lower surface of the first clamping portion 23b. The protrusion 25 is disposed at the radial center of the first clamping portion 23b and is located at a position radially separated from the first cylindrical wall 23a and the connecting portion 23c.

[0054] The plurality of connecting portions 23c are arranged circumferentially. A first through hole 24c that penetrates the first partition plate 23 is formed by a portion surrounded by the outer peripheral edge of the first clamping portion 23b, the connecting portions 23c adjacent in the circumferential direction, and the inner peripheral edge of the outer peripheral portion 23d. A plurality of (eight in this embodiment) of the first through holes 24c are also arranged circumferentially.

[0055] A cylindrical portion 23e extends upward from the outer peripheral portion 23d, and a flange 23f extends radially outward from the upper end edge of the cylindrical portion 23e. The cylindrical portion 23e is inserted into the inner peripheral side of the cylindrical member 21 until the flange 23f contacts the upper end of the cylindrical member 21. The flange 23f and the upper end of the cylindrical member 21 are joined by a fastening connection member such as a bolt, welding, bonding, etc., so that the first partition plate 23 is fixed to the cylindrical member 21.

[0056] The second partition plate 26 is a portion integrally formed with the cylindrical member 21 and is formed in a substantially circular plate shape perpendicular to the axis C. A cylindrical second cylindrical wall 26a centered on the axis C protrudes upward (toward the first partition plate 23 side) from the upper surface of the second partition plate 26, which is the position facing the first cylindrical wall 23a. The second cylindrical wall 26a has the same inner and outer diameters as the first cylindrical wall 23a. On the second partition plate 26, a second valve hole 27a is formed through in the plate thickness direction (vertical direction) at a position radially inside the second cylindrical wall 26a and on the axis C.

[0057] The second partition plate 26 includes: a ring-shaped second clamping portion 26b that extends radially outward from the second cylindrical wall 26a; a plurality of connecting portions 26c that extend radially outward and downward from the outer peripheral edge of the second clamping portion 26b; and an annular outer peripheral portion 26d that is connected to the inner peripheral edge of the connecting portion 26c. An annular protrusion 28 centered on the axis C protrudes from the upper surface of the second clamping portion 26b. The protrusion 28 is disposed at the radial center of the second clamping portion 26b and is located at a position radially separated from the second cylindrical wall 26a and the connecting portion 26c. The protrusion 28 and the protrusion 25 are opposed to each other in the axial direction.

[0058] A plurality of connecting portions 26c are arranged in the circumferential direction such that they are axially opposed to the plurality of connecting portions 23c of the first partition plate 23 respectively. A second through-hole 27c penetrating the second partition plate 26 is formed by a portion surrounded by the outer peripheral edge of the second clamping portion 26b, the connecting portions 26c adjacent in the circumferential direction, and the inner peripheral edge of the outer peripheral portion 26d. A plurality of the second through-holes 27c are also arranged in the circumferential direction such that they are axially opposed to the first through-holes 24c.

[0059] As Figure 1 and Figure 4 shown, the outer peripheral edge of the outer peripheral portion 26d is connected to the inner peripheral surface of the cylindrical member 21 over the entire circumference. Thereby, a predetermined space is formed between the first partition plate 23 and the second partition plate 26. Specifically, this space includes: a cylindrical inner space 29a provided inside the first cylindrical wall 23a and the second cylindrical wall 26a; an annular clamping space 29b between the first clamping portion 23b and the second clamping portion 26b; and a housing space 29c connected to the outer peripheral side of the clamping space 29b.

[0060] Through the central hole 24a and the first valve hole 24b, the inner space 29a communicates with the first liquid chamber 17. Through the second valve hole 27a, the inner space 29a communicates with the second liquid chamber 18. The housing space 29c is a space extending upward and downward with respect to the clamping space 29b, and an outer peripheral wall surface 29d is formed by the inner peripheral surface of the cylindrical member 21. Through the first through-hole 24c, the housing space 29c communicates with the first liquid chamber 17. Through the second through-hole 27c, the housing space 29c communicates with the second liquid chamber 18.

[0061] As Figure 1 and Figure 3 shown, the valve 30 is a member made of an elastic body such as rubber or thermoplastic elastomer, and is formed in a disc shape centered on the axis C. The valve 30 is housed in the inner space 29a between the first partition plate 23 and the second partition plate 26. The outer peripheral portion of the valve 30 is sandwiched between the first cylindrical wall 23a and the second cylindrical wall 26a over the entire circumference. The sandwiched outer peripheral portion is connected to the switching film 40.

[0062] The valve 30 includes: a cylindrical valve portion 31 protruding upward from the upper surface toward the first partition plate 23; a cylindrical valve portion 32 protruding downward from the lower surface toward the second partition plate 26; and a plurality of ribs 33 reinforcing the cylindrical valve portions 31, 32. A plurality of valve hole portions 34 penetrating the valve 30 in the plate thickness direction are formed at a position radially outside the cylindrical valve portions 31, 32 and radially inside the first cylindrical wall 23a and the second cylindrical wall 26a. The plurality of valve hole portions 34 are arranged in the circumferential direction so as to be respectively opposed to the plurality of first valve holes 24b.

[0063] The cylinder valve parts 31 and 32 are formed in a cylindrical shape centered on the axis C. The outer peripheral surfaces of the cylinder valve parts 31 and 32 are formed in a conical shape that tapers towards the front end. The cylinder valve part 31 and the cylinder valve part 32 are arranged symmetrically above and below.

[0064] In the no-load state of the liquid-filled vibration isolator 10, the cylinder valve part 31 contacts the first partition plate 23 over the entire circumference, radially outside the central hole 24a and radially inside the plurality of first valve holes 24b. In addition, in the no-load state, the cylinder valve part 32 contacts the second partition plate 26 over the entire circumference, radially outside the second valve hole 27a. Thus, in the no-load state, the valve 30 cuts off the movement of the liquid between the first liquid chamber 17 and the second liquid chamber 18 via the inner space 29a.

[0065] On the other hand, when a large load (vibration with a large amplitude) is input to the liquid-filled vibration isolator 10 and the first liquid chamber 17 is excessively negative pressured as the vibration isolation base 13 deforms, the valve 30 displaces towards the first partition plate 23 side, and the cylinder valve part 31 is flattened. As a result, the cylinder valve part 32 separates from the second partition plate 26. As a result, the liquid flows from the second liquid chamber 18 into the first liquid chamber 17 through the second valve hole 27a, the inner space 29a, the valve hole part 34, and the first valve hole 24b. Therefore, the excessive negative pressure in the first liquid chamber 17 can be eliminated, and the cavitation accompanying this negative pressure can be suppressed. The part that functions in this way is called a cavitation valve.

[0066] In addition, when the first liquid chamber 17 is under positive pressure, only the force pressing the cylinder valve part 32 against the second partition plate 26 becomes stronger. Therefore, the movement of the liquid via the inner space 29a is cut off by the valve 30 in the same way as in the no-load state. In addition, the hydraulic pressure from the first liquid chamber 17 is applied to the center of the valve 30 via the central hole 24a, so that it is difficult for the liquid to leak through the gap between the cylinder valve part 32 and the second partition plate 26.

[0067] The ribs 33 project from the upper and lower surfaces of the valve 30 radially inside the cylinder valve parts 31 and 32. In addition, the ribs 33 extend radially from the axis C and are connected to the inner peripheral surfaces of the cylinder valve parts 31 and 32. By means of these ribs 33, it is difficult for the cylinder valve parts 31 and 32 to tilt radially. As a result, it is possible to suppress the leakage of the liquid through the gap between the cylinder valve part 32 and the second partition plate 26 due to the tilting of the cylinder valve parts 31 and 32.

[0068] As Figure 1 and Figure 4 shown, the switching film 40 is an annular member made of an elastomer such as rubber or thermoplastic elastomer. The valve 30 is connected to the inner peripheral edge of the switching film 40 over the entire circumference. The switching film 40 and the valve 30 are integrally formed. Therefore, compared with the case where they are formed separately and then integrated, the productivity of the switching film 40 and the valve 30 can be improved.

[0069] The switching film 40 includes: a plate portion 41 in the shape of an annular plate centered on the axis C; and a pair of cylindrical valve portions 42, 43 respectively protruding from both sides of the plate portion 41 in the vertical direction (plate thickness direction). The inner peripheral edge of the plate portion 41 is connected to the valve 30. In addition, Figure 4 the boundaries between the plate portion 41 and the valve portions 42, 43 are indicated by dashed lines in

[0070] The plate portion 41 is disposed throughout the entire circumference within the clamping space 29b, and a part of the outer peripheral edge 41c side extends into the accommodation space 29c. The outer peripheral edge 41c of the plate portion 41 is disposed opposite to the outer peripheral wall surface 29d of the accommodation space 29c with a radial gap therebetween throughout the entire circumference.

[0071] The plate portion 41 is formed of an annular thick wall portion 41a from the inner peripheral edge to approximately the center in the radial direction. The thick wall portion 41a is formed to be thicker in the vertical direction than the portion on the outer peripheral edge 41c side (outside the thick wall portion 41a) of the plate portion 41. The thick wall portion 41a is axially sandwiched between the first clamping portion 23b and the second clamping portion 26b. In addition, the thick wall portion 41a is respectively accommodated between the first cylindrical wall 23a and the protrusion 25, and between the second cylindrical wall 26a and the protrusion 28. Thereby, the switching film 40 is positioned in the vertical direction and the radial direction with respect to the first partition plate 23 and the second partition plate 26.

[0072] A plurality of clamping protrusions 41b respectively protrude in the vertical direction from the upper and lower surfaces of the plate portion 41. The clamping protrusions 41b are located at positions radially outward from the thick wall portion 41a. The front ends of the clamping protrusions 41b come into contact with the vicinity of the outer peripheral edges of the first clamping portion 23b and the second clamping portion 26b. Through the clamping protrusions 41b, the plate portion 41 is clamped between the first partition plate 23 and the second partition plate 26 near the outer peripheral edge of the clamping space 29b.

[0073] A plurality of (16 in this embodiment) clamping protrusions 41b are arranged in the circumferential direction centered on the axis C (refer to Figure 3 ). Thereby, via the first through hole 24c or the second through hole 27c, the clamping space 29b, and between the plurality of clamping protrusions 41b, a change in the hydraulic pressure in the first liquid chamber 17 or the second liquid chamber 18 is applied to the plate portion 41 between the thick wall portion 41a and the clamping protrusions 41b. The plate portion 41 at this portion deforms according to the change in the hydraulic pressure, whereby the vibration energy input to the liquid-filled vibration isolator 10 is consumed, and the dynamic spring constant of the liquid-filled vibration isolator 10 can be reduced.

[0074] The valve part 42 is a conical cylindrical part that protrudes upward and radially outward from the entire circumference of the outer peripheral edge 41c of the plate part 41. Except for the front end part, the outer peripheral surface of the valve part 42 is formed by an inclined surface 42a that is inclined radially inward toward the center in the vertical direction of the plate part 41. Similarly, the valve part 43 is a conical cylindrical part that protrudes downward and radially outward from the entire circumference of the outer peripheral edge 41c of the plate part 41. Except for the front end part, the outer peripheral surface of the valve part 43 is formed by an inclined surface 43a that is inclined radially inward toward the center in the vertical direction of the plate part 41.

[0075] The outer peripheral surface of the switching film 40 is formed by the inclined surfaces 42a, 43a and the outer peripheral edge 41c of the plate part 41. In the no-load state, a gap is provided throughout the entire circumference between the outer peripheral surface of the switching film 40 and the outer peripheral wall surface 29d of the accommodation space 29c. In addition, in the no-load state, a gap is also provided throughout the entire circumference between the front end parts of the valve parts 42, 43 and the upper and lower wall surfaces (outer peripheral parts 23d, 26d) of the accommodation space 29c.

[0076] Through these gaps, the first through hole 24c, and the second through hole 27c in the accommodation space 29c, a second throttle hole that communicates the first liquid chamber 17 and the second liquid chamber 18 is formed. For example, in order to reduce the idle vibration during idling (when the vehicle is stopped), the flow path cross-sectional area, length, cross-sectional perimeter, etc. of the second throttle hole are set so that the spring constant becomes lower in the frequency band corresponding to the idle vibration (for example, around 15 to 50 Hz) when small-amplitude idle vibration is input.

[0077] When a hydraulic pressure difference is generated between the first liquid chamber 17 and the second liquid chamber 18 due to the application of a load to the liquid-filled vibration isolator 10, a liquid flow is generated in the second throttle hole. For example, when a liquid flow is generated in the second throttle hole from the first liquid chamber 17 toward the second liquid chamber 18, the valve part 42 on the first liquid chamber 17 side deforms in a manner of tilting radially outward. When the hydraulic pressure applied to the valve part 42 becomes large, as Figure 4 indicated by the double-dot dash line in, the valve part 42 contacts the outer peripheral wall surface 29d, and the second throttle hole is cut off. Similarly, when a liquid flow is generated in the second throttle hole from the second liquid chamber 18 toward the first liquid chamber 17, when the valve part 43 deforms in a manner of tilting radially outward and contacts the outer peripheral wall surface 29d, the second throttle hole is cut off.

[0078] The state in which the second throttle hole is cut off is referred to as the cut-off state. On the other hand, the state in which both the valve parts 42 and 43 are separated from the outer peripheral wall surface 29d and the second throttle hole is in communication is referred to as the communication state. In the cut-off state of the second throttle hole, the attenuation characteristic based on the first throttle hole 19 is mainly exhibited. In the communication state of the second throttle hole, the attenuation characteristics of both the first throttle hole 19 and the second throttle hole are exhibited. That is, by switching the communication state and the cut-off state of the second throttle hole, the attenuation characteristic of the liquid-filled vibration isolator 10 is switched.

[0079] Here, when the second throttle hole is cut off by one of the pair of valve parts 42 and 43, the other of the valve parts 42 and 43 does not contribute to this cut-off. If the other of the valve parts 42 and 43 that does not function is greatly deformed due to liquid flow, the durability of the valve parts 42 and 43 may be reduced.

[0080] In response to this, in the present embodiment, the outer peripheral surfaces of the valve parts 42 and 43 are respectively formed by inclined surfaces 42a and 43a that are inclined radially inward toward the center in the plate thickness direction of the plate part 41. In addition, each of the inclined surfaces 42a and 43a extends in such a manner as to include not only the outer peripheral surfaces of the valve parts 42 and 43 but also a part of the outer peripheral edge 41c of the plate part 41. The outer peripheral surface of the switching film 40 including such inclined surfaces 42a and 43a is reduced in diameter radially inward in the vicinity of the plate part 41.

[0081] Thereby, it is possible to easily cause one of the pair of valve parts 42 and 43 located on both sides of the diameter reduction to fall radially outward independently of the other. Therefore, when the second throttle hole is cut off by one of the valve parts 42 and 43, deformation of the other of the valve parts 42 and 43 can be suppressed, and thus the durability of the valve parts 42 and 43 can be improved.

[0082] The inner peripheral surface 42b of the valve part 42 is formed substantially parallel to the inclined surface 42a as a whole except for the front end portion. That is, the inner peripheral surface 42b is inclined radially inward toward the plate part 41. Similarly, the inner peripheral surface 43b of the valve part 43 is formed substantially parallel to the inclined surface 43a as a whole except for the front end portion. That is, the inner peripheral surface 43b is inclined radially inward toward the plate part 41.

[0083] Thereby, it is possible to make the thicknesses (dimensions in the direction perpendicular to the inclined surfaces 42a and 43a) of the valve parts 42 and 43 substantially constant. Therefore, when the valve parts 42 and 43 fall, deformation can be suppressed from concentrating on the thin portions of the valve parts 42 and 43. As a result, the durability of the valve parts 42 and 43 can be further improved.

[0084] The valve portions 42 and 43 with a substantially constant thickness extend obliquely outward in the radial direction from the plate portion 41. Therefore, the circumferential free length of the valve portions 42 and 43 becomes longer toward the front end portions of the valve portions 42 and 43. In addition, when the valve portions 42 and 43 are tilted outward in the radial direction, they are greatly elongated and deformed in the circumferential direction toward the front end portions of the valve portions 42 and 43. Thus, the more the portion is greatly elongated and deformed in the circumferential direction, the longer the original free length is. Therefore, deformation can be suppressed from concentrating on a part of the valve portions 42 and 43, and the durability of the valve portions 42 and 43 can be further improved.

[0085] A concave portion 42c that is recessed inward in the radial direction is formed on the outer peripheral edge 41c side of the inclined surface 42a. Similarly, a concave portion 43c that is recessed inward in the radial direction is formed on the outer peripheral edge 41c side of the inclined surface 43a. The valve portion 42 is likely to tilt with the concave portion 42c as a fulcrum, and the valve portion 43 is likely to tilt with the concave portion 43c as a fulcrum. Therefore, the pair of valve portions 42 and 43 are less likely to deform integrally, and the durability of the valve portions 42 and 43 can be further improved.

[0086] In addition, the concave portions 42c and 43c are respectively formed across the outer peripheral surfaces of the valve portions 42 and 43 and the outer peripheral edge 41c of the plate portion 41. As a result, the valve portions 42 and 43 are likely to tilt from the root (the boundary with the plate portion 41). Therefore, compared with the case where the valve portions 42 and 43 are bent midway, the time from the start of tilting of the valve portions 42 and 43 to the contact with the outer peripheral wall surface 29d can be shortened. As a result, the switching sensitivity of the second throttle hole from the communication state to the cut-off state can be improved.

[0087] A convex portion 42d that bulges inward in the radial direction on the side opposite to the radial direction of the concave portion 42c is provided on the inner peripheral surface 42b of the valve portion 42. A convex portion 43d that bulges inward in the radial direction on the side opposite to the radial direction of the concave portion 43c is provided on the inner peripheral surface 43b of the valve portion 43. As a result, even when the concave portions 42c and 43c are provided, the thickness of the valve portions 42 and 43 can be made to approach substantially constant by the convex portions 42d and 43d. As a result, when the valve portions 42 and 43 are deformed, deformation can be suppressed from concentrating near the concave portions 42c and 43c and reducing the durability of the valve portions 42 and 43.

[0088] In particular, the convex portions 42d and 43d extend toward the front end portions of the valve portions 42 and 43 and are provided up to the boundary with the plate portion 41 compared with the positions where the concave portions 42c and 43c are projected in the width direction of the valve portions 42 and 43. As a result, when the valve portions 42 and 43 tilt with the concave portions 42c and 43c as fulcrums, the free length near the convex portions 42d and 43d where the main elongation deformation occurs can be ensured. Therefore, concentration of deformation near them can be suppressed. Therefore, the durability of the valve portions 42 and 43 can be further improved.

[0089] The shortest distance L1 from the portion of the plate portion 41 sandwiched between the first partition plate 23 and the second partition plate 26 to the valve portions 42 and 43 is shortened by the contact of the clamping protrusion 41b with the first partition plate 23 and the second partition plate 26. This shortest distance L1 is less than or equal to half of the length L2 in the protruding direction (the direction perpendicular to the width direction) of the valve portions 42 and 43. The length L2 is the dimension from the plate portion 41 to the front end portions of the valve portions 42 and 43 at the center in the width direction of the valve portions 42 and 43.

[0090] According to such dimensional relationships, it is possible to suppress the plate portion 41 from flexing up and down between the portion of the plate portion 41 sandwiched between the first partition plate 23 and the second partition plate 26 and the valve portions 42 and 43 due to the liquid flow in the second throttle hole. That is, by this liquid flow, it is possible to suppress the switching film 40 from being displaced in the up and down direction as a whole within the accommodation space 29c, and it is possible to make only the valve portions 42 and 43 prone to tipping over.

[0091] The first through hole 24c and the second through hole 27c open into the accommodation space 29c at positions radially opposed to the inner peripheral surfaces 42b and 43b of the valve portions 42 and 43. Therefore, it is possible to make the valve portions 42 and 43 tip over in the same direction as the flow of the liquid flowing out from the first through hole 24c and the second through hole 27c into the accommodation space 29c. Thereby, it is possible to make the valve portions 42 and 43 quickly contact the outer peripheral wall surface 29d, and thus it is possible to improve the switching sensitivity of the second throttle hole from the communication state to the cut-off state.

[0092] In addition, the first through hole 24c and the second through hole 27c open into the accommodation space 29c at positions radially opposed to the front end portions of the valve portions 42 and 43. Therefore, the hydraulic pressure from the first through hole 24c and the second through hole 27c is easily applied to the front end portions of the valve portions 42 and 43, and thus it is possible to make the valve portions 42 and 43 prone to tipping over from the root by the lever principle. As a result, it is possible to make the valve portions 42 and 43 contact the outer peripheral wall surface 29d more quickly, and thus it is possible to further improve the switching sensitivity of the second throttle hole from the communication state to the cut-off state.

[0093] Next, refer to Figure 5 The second embodiment will be described. In the first embodiment, the case where the wall surfaces on the plate portion 41 side of the first through hole 24c and the second through hole 27c are substantially parallel to the radial direction was described. In contrast, in the second embodiment, the case where the wall surfaces 51 and 52 on the plate portion 41 side of the first through hole 24c and the second through hole 27c are inclined with respect to the radial direction will be described. In addition, the same reference numerals are given to the same parts as in the first embodiment, and the following description is omitted.

[0094] Figure 5 is a partial enlarged cross-sectional view of the liquid-filled vibration isolator 50 in the second embodiment.Figure 5 The cross-sectional view is Figure 4 The liquid-filled vibration isolating device 50 is configured substantially the same as the liquid-filled vibration isolating device 10 of the first embodiment, except for the wall surfaces 51 and 52 on the plate portion 41 side of the first through hole 24 c and the second through hole 27 c.

[0095] The wall surface 51 of the first through hole 24c is the outer edge portion of the upper surface of the first clamping portion 23b, and is inclined toward the plate portion 41 side (lower side) as it moves toward the radial outer side. The wall surface 52 of the second through hole 27c is the outer edge portion of the lower surface of the second clamping portion 26b, and is inclined toward the plate portion 41 side (upper side) as it moves toward the radial outer side. As a result, the flow of the liquid flowing out from the first through hole 24c and the second through hole 27c to the accommodating space 29c acts roughly perpendicularly on the inner peripheral surfaces 42b and 43b of the valve portions 42 and 43, so that the valve portions 42 and 43 can quickly contact the outer peripheral wall surface 29d. As a result, the switching sensitivity of the second throttle hole from the connected state to the cut-off state can be improved.

[0096] Furthermore, if the angle formed by the inner peripheral surface 42b and the wall surface 51, and the angle formed by the inner peripheral surface 43b and the wall surface 52 are within the range of 70 to 110 degrees, the direction of the flow of the liquid from the first through hole 24c and the second through hole 27c is closer to perpendicular to the inner peripheral surfaces 42b and 43b. Therefore, the valve portions 42 and 43 can be brought into contact with the outer peripheral wall surface 29d more quickly, and the switching sensitivity of the second throttle hole from the connected state to the cut-off state can be further improved.

[0097] Next, refer to Figure 6 The third embodiment is described. In the first embodiment, the case where the valve portions 42 and 43 extend obliquely from the plate portion 41 toward the radially outer side is described. In contrast, in the third embodiment, the case where the valve portions 62 and 63 stand up approximately vertically from the plate portion 41 is described. In addition, the same reference numerals are given to the same parts as those in the first embodiment, and the following description is omitted.

[0098] Figure 6 It is a partially enlarged cross-sectional view of a liquid-filled anti-vibration device 60 in the third embodiment. Figure 6 The cross-sectional view is Figure 4 The liquid-filled vibration isolation device 60 is configured substantially the same as the liquid-filled vibration isolation device 10 of the first embodiment except for the switching membrane 61 .

[0099] The switching membrane 61 includes: a circular plate-shaped plate portion 41; and a pair of cylindrical valve portions 62 and 63 protruding from the plate portion 41 on both sides in the plate thickness direction (vertical direction). Figure 6 In the figure, the boundary between the plate portion 41 and the valve portions 62 and 63 is indicated by a dotted line.

[0100] The valve part 62 is a cylindrical part that protrudes substantially vertically upward from the entire circumference of the outer peripheral edge 41c of the plate part 41. The outer peripheral surface 62a and the inner peripheral surface 62b of the valve part 62 are parallel to each other and parallel to the vertical direction, and the thickness (radial dimension) of the valve part 62 is substantially constant. The valve part 63 is a cylindrical part that protrudes substantially vertically downward from the entire circumference of the outer peripheral edge 41c of the plate part 41. The outer peripheral surface 63a and the inner peripheral surface 63b of the valve part 63 are parallel to each other and parallel to the vertical direction, and the thickness (radial dimension) of the valve part 63 is substantially constant.

[0101] On the outer peripheral surface of the switching film 61 including these outer peripheral surfaces 62a, 63a and the outer peripheral edge 41c of the plate part 41, inclined surfaces 64, 65 that are inclined radially inward toward the center in the plate thickness direction of the plate part 41 are respectively formed at positions including the outer peripheral edge 41c. The inclined surface 64 is formed from a part on the root side of the outer peripheral surface 62a to the center in the plate thickness direction of the outer peripheral edge 41c. The inclined surface 65 is formed from a part on the root side of the outer peripheral surface 63a to the center in the plate thickness direction of the outer peripheral edge 41c. That is, the outer peripheral surface of the switching film 61 is reduced in diameter radially inward in the vicinity of the plate part 41 by the inclined surfaces 64, 65.

[0102] Accordingly, also in the third embodiment, it is possible to easily incline one of the pair of valve parts 62, 63 radially outward independently of the other in the same manner as in the first embodiment. Therefore, when one of the valve parts 62, 63 cuts off the second throttle hole, it is possible to suppress the deformation of the other of the valve parts 62, 63, and thus the durability of the valve parts 62, 63 can be improved.

[0103] In addition, the inclined surfaces 64, 65 may be formed at least on the outer peripheral edge 41c, and may not be formed on the outer peripheral surfaces 62a, 63a of the valve parts 62, 63. Even in this case, it is possible to easily incline one of the pair of valve parts 62, 63 radially outward independently of the other, and the durability of the valve parts 62, 63 can be improved.

[0104] However, by forming the inclined surfaces 64, 65 up to the outer peripheral surfaces 62a, 63a, it is possible to easily make the deformation of one of the pair of valve parts 62, 63 independent of the deformation of the other. As a result, the durability of the valve parts 62, 63 can be further improved.

[0105] In addition, when the inclined surfaces 64 and 65 are formed up to the outer peripheral surfaces 62a and 63a, although not shown, convex portions 42d and 43d as in the first embodiment may be provided so as to bulge the inner peripheral surfaces 62b and 63b on the opposite side in the radial direction with respect to the inclined surfaces 64 and 65. Thus, even when the inclined surfaces 64 and 65 are provided on the valve portions 62 and 63 having a substantially constant thickness, the thickness of the valve portions 62 and 63 can be kept substantially constant. As a result, when the valve portions 62 and 63 are deformed, it is possible to suppress deformation from concentrating near the inclined surfaces 64 and 65 and reduce the durability of the valve portions 62 and 63.

[0106] The shortest distance L3 from the portion where the plate portion 41 is sandwiched between the first partition plate 23 and the second partition plate 26 (the clamping projection 41b) to the valve portions 62 and 63 is equal to or less than the length L4 in the protruding direction (the vertical direction) of the valve portions 62 and 63. Thus, similar to the first embodiment, it is possible to suppress the switching film 61 from being displaced in the vertical direction as a whole in the accommodation space 29c by the liquid flow in the second throttle hole, and it is only possible to easily tilt the valve portions 62 and 63.

[0107] Next, Figure 7 a description will be given of the fourth embodiment. In the first embodiment, the case where the inner peripheral side of the annular switching film 40 is sandwiched between the first partition plate 23 and the second partition plate 26 has been described. In contrast, in the fourth embodiment, the case where the outer peripheral side of the annular switching film 80 is sandwiched between the first partition plate 71 and the second partition plate 73 will be described. In addition, the same reference numerals are given to the same parts as in the first embodiment, and the following description will be omitted.

[0108] Figure 7 is a cross-sectional view of the partition body 70 of the liquid-filled vibration isolator in the fourth embodiment. Figure 7 The cross-sectional view is a cross-sectional view including the axis C. The partition body 70 is a component assembled to the liquid-filled vibration isolator 10 in place of the partition body 20 in the first embodiment.

[0109] The partition body 70 includes: a cylindrical member 21; flat first and second partition plates 71 and 73 that vertically partition the inner peripheral side of the cylindrical member 21; and a switching film 80 disposed between the first partition plate 71 and the second partition plate 73. The first partition plate 71 faces the first liquid chamber 17, and the second partition plate 73 faces the second liquid chamber 18.

[0110] The first partition plate 71 is a part made of metal or synthetic resin, and is formed in a substantially disc shape perpendicular to the axis C. The first partition plate 71 includes: a first clamping portion 71a in the shape of an annular plate forming the outer peripheral side of the first partition plate 71; a plurality of connecting portions 71b extending radially inward and upward from the inner peripheral edge of the first clamping portion 71a; and a disc-shaped inner peripheral portion 71c connecting the connecting portions 71b to its outer peripheral edge.

[0111] The cylindrical portion 23e extends upward from the outer peripheral edge of the first clamping portion 71a, and the flange 23f extends radially outward from the upper end edge of the cylindrical portion 23e. An annular protrusion 74 centered on the axis C protrudes from the lower surface of the first clamping portion 71a. The protrusion 74 is provided from the radial center of the first clamping portion 71a to the inner peripheral edge.

[0112] The plurality of connecting portions 71b are arranged in the circumferential direction. A first through hole 71d penetrating the first partition plate 71 is formed by a portion surrounded by the inner peripheral edge of the first clamping portion 71a, the connecting portions 71b adjacent in the circumferential direction, and the outer peripheral edge of the inner peripheral portion 71c. A plurality of the first through holes 71d are also arranged in the circumferential direction.

[0113] The second partition plate 73 is a part integrally formed with the cylindrical member 21, and is formed in a disc shape perpendicular to the axis C. The second partition plate 73 includes: a second clamping portion 73a in the shape of an annular plate extending radially inward from the inner peripheral surface of the cylindrical member 21; a plurality of connecting portions 73b extending radially inward and downward from the inner peripheral edge of the second clamping portion 73a; an annular inner peripheral portion 73c whose outer peripheral edge is connected to the connecting portions 73b; a cylindrical portion 73d extending upward from the inner peripheral edge of the inner peripheral portion 73c; and a disc-shaped disc portion 73e closing the upper end of the cylindrical portion 73d. An annular protrusion 75 centered on the axis C protrudes from the lower surface of the second clamping portion 73a. The protrusion 75 is provided from the radial center of the second clamping portion 73a to the inner peripheral edge.

[0114] The plurality of connecting portions 73b are arranged in the circumferential direction so as to be axially opposed to the connecting portions 71b of the first partition plate 71. A second through hole 73f penetrating the second partition plate 73 is formed by a portion surrounded by the inner peripheral edge of the second clamping portion 73a, the connecting portions 73b adjacent in the circumferential direction, and the outer peripheral edge of the inner peripheral portion 73c. A plurality of the second through holes 73f are also arranged in the circumferential direction so as to be axially opposed to the first through holes 71d.

[0115] The first partition plate 71 is joined to the second partition plate 73 by overlapping the inner peripheral portion 71c of the first partition plate 71 on the upper surface of the circular plate portion 73e and welding and bonding them. In this joined state, a predetermined space is formed between the first partition plate 71 and the second partition plate 73. Specifically, this space includes: an annular clamping space 76 between the first clamping portion 71a and the second clamping portion 73a; and a housing space 77 connected to the inner peripheral side of the clamping space 76.

[0116] The housing space 77 is a space that extends upward and downward with respect to the clamping space 76, and the inner peripheral wall surface 78 is formed by the outer peripheral surface of the cylindrical portion 73d. Through the first through-hole 71d, the housing space 77 communicates with the first liquid chamber 17 (see Figure 1 ). Through the second through-hole 73f, the housing space 77 communicates with the second liquid chamber 18 (see Figure 1 ).

[0117] The switching film 80 is an annular member made of an elastomer such as rubber or thermoplastic elastomer. The switching film 80 includes: a circular plate-like plate portion 81 centered on the axis C; and a pair of cylindrical valve portions 82 and 83 protruding from both sides of the plate portion 81 in the up-and-down direction (plate thickness direction).

[0118] The plate portion 81 is disposed throughout the entire circumference within the clamping space 76, and a part of the inner peripheral edge 81c side extends into the housing space 77. The inner peripheral edge 81c of the plate portion 81 is disposed opposite to the inner peripheral wall surface 78 of the housing space 77 at a radial interval throughout the entire circumference.

[0119] The plate portion 81 is formed by an annular thick-walled portion 81a from the outer peripheral edge to the substantially center in the radial direction. The thick-walled portion 81a is formed thicker up and down with respect to the portion of the plate portion 81 on the inner peripheral edge 81c side (outside the thick-walled portion 81a). The thick-walled portion 81a is axially sandwiched between the first clamping portion 71a and the second clamping portion 73a. In addition, the thick-walled portion 81a is housed between the inner peripheral surface of the cylindrical member 21 and the protrusions 74 and 75, and the plate portion 81 outside the thick-walled portion 81a is also axially sandwiched between the protrusions 74 and 75. Thus, the switching film 80 fills substantially the entire clamping space 76 and is positioned in the up-and-down direction and the radial direction with respect to the first partition plate 71 and the second partition plate 73.

[0120] The valve portion 82 is a conical cylindrical portion that protrudes upward and radially inward from the entire circumference of the inner peripheral edge 81c of the plate portion 81. The valve portion 82 is a member obtained by inverting the inner and outer sides in the radial direction with respect to the valve portion 42 of the first embodiment. That is, the inclined surface 82a, the outer peripheral surface 82b, the concave portion 82c, and the convex portion 82d of the valve portion 82 are obtained by inverting the inclined surface 42a, the inner peripheral surface 42b, the concave portion 42c, and the convex portion 42d of the valve portion 42, respectively.

[0121] Similarly, the valve portion 83 is a conical cylindrical portion that protrudes downward and radially inward from the entire circumference of the inner peripheral edge 81c of the plate portion 81. The valve portion 83 is a component obtained by reversing the inner and outer sides in the radial direction with respect to the valve portion 43 of the first embodiment. That is, the inclined surface 83a, outer peripheral surface 83b, concave portion 83c, and convex portion 83d of the valve portion 83 are components obtained by reversing the inner and outer sides of the inclined surface 43a, inner peripheral surface 43b, concave portion 43c, and convex portion 43d of the valve portion 43, respectively.

[0122] In addition, the accommodation space 77, inner peripheral wall surface 78, first through hole 71d, second through hole 73f, and second throttle hole are also components obtained by reversing the inner and outer sides in the radial direction with respect to the accommodation space 29c, outer peripheral wall surface 29d, first through hole 24c, second through hole 27c, and second throttle hole of the first embodiment, respectively.

[0123] Therefore, the liquid-filled vibration isolator according to the fourth embodiment exhibits the same effects as the liquid-filled vibration isolator 10 of the first embodiment. For example, specifically, the inner peripheral surfaces of the valve portions 82 and 83 are formed by inclined surfaces 82a and 83a that are inclined radially outward toward the center in the plate thickness direction of the plate portion 81. In addition, the respective inclined surfaces 82a and 83a are extended and provided in such a manner as to include not only the inner peripheral surfaces of the valve portions 82 and 83 but also a part of the inner peripheral edge 81c of the plate portion 81. The inner peripheral surface of the switching film 80 including such inclined surfaces 82a and 83a is reduced in diameter radially inward in the vicinity of the plate portion 81.

[0124] Thereby, it is possible to easily tilt one of the pair of valve portions 82 and 83 located on both sides of the diameter reduction independently of the other. Therefore, when one of the valve portions 82 and 83 cuts off the second throttle hole, it is possible to suppress the deformation of the other of the valve portions 82 and 83, and thus the durability of the valve portions 82 and 83 can be improved.

[0125] As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above embodiments, and it is easily inferred that various improvements and modifications can be made without departing from the gist of the present invention. For example, the number of the first through hole 24c, the second through hole 27c, the clamping protrusion 41b, etc. can be appropriately changed.

[0126] The first component 11 may also be arranged at a position offset radially from the axis C. In addition, the axis C of the second component 12 and the axis C of the valve 30, switching films 40, 61, 80, accommodation spaces 29c, 77, etc. may also be offset.

[0127] The formation position, length, etc. of the first throttle hole 19 can also be appropriately changed. A liquid chamber different from the first liquid chamber 17 and the second liquid chamber 18 can also be formed within the partition bodies 20, 70, etc. The two liquid chambers can also be communicated through a throttle hole different from the first throttle hole 19. The first throttle hole 19 can also be omitted.

[0128] A cup-shaped cover fitting can also be provided below the diaphragm 15 (on the side opposite to the first liquid chamber 17 and the second liquid chamber 18), and an air chamber is formed by the inner surface of the cover fitting and the diaphragm 15. The air chamber can also have an air spring effect as a closed space. A through hole can also be provided in a part of the cover fitting to open the air chamber to the atmosphere, and the damping effect generated by the air passing through the through hole is applied to the liquid-filled vibration isolators 10, 50, 60.

[0129] In the above-described embodiment, engine mounts are exemplified as the application objects of the liquid-filled vibration isolators 10, 50, 60, but the application objects are arbitrary. As other application objects, for example, motor mounts, component mounts, and differential mounts can be exemplified. In addition, it is not limited to the case where the first component 11 is installed on the vibration source side such as an engine and the second component 12 is installed on the vibration receiving side such as a vehicle body. The second component 12 can also be installed on the vibration source side and the first component 11 can be installed on the vibration receiving side.

[0130] In the above-described embodiment, the case where the vibration isolation base 13 constitutes a part of the chamber wall of the first liquid chamber 17 and the diaphragm 15 constitutes a part of the chamber wall of the second liquid chamber 18 has been described, but it is not necessarily limited thereto. For example, the second liquid chamber 18 can also be referred to as the first liquid chamber, and the first liquid chamber 17 can also be referred to as the second liquid chamber.

[0131] A part of the above-described embodiment can also be omitted. For example, the film portion 14 can also be omitted, and the partition bodies 20, 70, and the diaphragm 15 can be installed on the inner peripheral surface of the second component 12. The connecting portion between the valve 30 and the switching film 40 can also be omitted to make them independent. The valve 30 and the inner space 29a can also be omitted. In this case, the inner edge side of the switching film 40 can also be closed, and the switching film 40 is formed in a disc shape.

[0132] A part of each of the above-described embodiments can also be combined with a part of other embodiments. For example, the valve 30, the inner space 29a, etc. in the first embodiment can also be provided on the inner peripheral side of the cylindrical portion 73d in the fourth embodiment. The wall surfaces 51, 52 of the second embodiment obtained by inverting the inner and outer sides in the radial direction can also be provided in the fourth embodiment. The valve portions 82, 83 in the fourth embodiment can also protrude substantially perpendicularly from the plate portion 81 as in the third embodiment.

[0133] Alternatively, like the protruding portions 74 and 75 in the fourth embodiment, the protruding portions 25 and 28 in the first embodiment or the like may be provided up to the outer peripheral edges of the first clamping portion 23b and the second clamping portion 26b, and the clamping protrusion 41b may be omitted. Additionally, the protruding portions 25, 28, 74, 75, and the clamping protrusion 41b may be omitted, and the thick-walled portion 41a may be provided up to the outer peripheral edge of the clamping space 29b, or the thick-walled portion 81a may be provided up to the inner peripheral edge of the clamping space 76.

[0134] In the above-described embodiment, the case where a plurality of clamping protrusions 41b are arranged in the circumferential direction has been described, but it is not necessarily limited thereto. The clamping protrusion 41b may also be an annular member that is continuous throughout the entire circumference around the axis C. The clamping protrusion 41b may also be omitted.

[0135] In the above-described embodiment, the cases where the valve portions 42, 43, 62, 63, 82, and 83 are conical cylindrical or cylindrical have been described, but it is not necessarily limited thereto. The valve portions 42, 43, 62, 63, 82, and 83 only need to be cylindrical (ring-shaped in a cross-section perpendicular to the axis C). For example, in a cross-section perpendicular to the axis C, the valve portions 42, 43, 62, 63, 82, and 83 may also be ring-shaped such as a polygon, an ellipse, or an oblong.

Claims

1. A liquid-filled anti-vibration device, characterized in that: have: A first component and a second cylindrical component; an anti-vibration base made of an elastic material, connecting the first component and the second component; an elastic diaphragm mounted on the second member and forming a liquid chamber filled with liquid between the diaphragm and the vibration-proof base; a separator that separates the liquid chamber into a first liquid chamber and a second liquid chamber; a throttle hole formed in the partition body and communicating the first liquid chamber with the second liquid chamber; as well as A switching membrane made of an elastic system switches the connection state and the cut-off state of the throttle hole, The separator includes a first partition plate facing the first liquid chamber and a second partition plate facing the second liquid chamber. The throttle hole is formed by an annular receiving space formed between the first partition plate and the second partition plate, a plurality of first through holes formed through the first partition plate and communicating with the first liquid chamber and the receiving space, and a plurality of second through holes formed through the second partition plate and communicating with the second liquid chamber and the receiving space. The switching membrane includes: a plate portion having an outer peripheral edge that is radially opposed to the outer peripheral wall surface of the housing space over the entire circumference, and sandwiched between the first partition plate and the second partition plate in a manner that the outer peripheral edge side protrudes into the housing space; and a pair of cylindrical valve portions, which protrude from the entire circumference of the outer peripheral edge of the plate portion toward both sides in the plate thickness direction of the plate portion, respectively; In the communicating state, the valve portion is separated from the outer peripheral wall surface. In the cut-off state, the valve portion deformed radially outward contacts the outer peripheral wall surface to cut off the throttle hole. On the outer peripheral surface of the switching membrane including the outer peripheral edge and the outer peripheral surface of the valve portion, an inclined surface inclined radially inward toward the center of the plate portion in the plate thickness direction is formed at least at a position including the outer peripheral edge.

2. The liquid-filled anti-vibration device according to claim 1, characterized in that: The outer peripheral surface of the valve portion is formed by the inclined surface, and the inner peripheral surface of the valve portion is inclined along the inclined surface.

3. The liquid-filled anti-vibration device according to claim 2, characterized in that: A recessed portion recessed radially inward is formed on the outer peripheral edge side of the inclined surface.

4. The liquid-filled anti-vibration device according to claim 3, characterized in that: A convex portion is provided on the inner peripheral surface of the valve portion so that the radially opposite side to the concave portion bulges radially inward.

5. The liquid-filled anti-vibration device according to claim 3, characterized in that: The recessed portion is formed across the outer peripheral surface of the valve portion and the outer peripheral edge of the plate portion.

6. The liquid-filled anti-vibration device according to claim 2, characterized in that: The first through hole and the second through hole are respectively opened to the accommodation space at positions facing the inner peripheral surface of the valve portion in the radial direction. The wall surfaces of the first through hole and the second through hole on the plate portion side are each inclined toward the plate portion side as they go radially outward.

7. The liquid-filled anti-vibration device according to any one of claims 1 to 6, characterized in that: The shortest distance from a portion of the plate portion sandwiched between the first partition plate and the second partition plate to the valve portion is less than or equal to half of a length of the valve portion in a protruding direction.

8. A liquid-filled anti-vibration device, characterized in that: have: A first component and a second cylindrical component; an anti-vibration base made of an elastic material, connecting the first component and the second component; an elastic diaphragm mounted on the second member and forming a liquid chamber filled with liquid between the diaphragm and the vibration-proof base; a separator that separates the liquid chamber into a first liquid chamber and a second liquid chamber; a throttle hole formed in the partition body and communicating the first liquid chamber with the second liquid chamber; as well as A switching membrane made of an elastic system switches the connection state and the cut-off state of the throttle hole, The separator includes a first partition plate facing the first liquid chamber and a second partition plate facing the second liquid chamber. The throttle hole is formed by an annular receiving space formed between the first partition plate and the second partition plate, a plurality of first through holes formed through the first partition plate and communicating with the first liquid chamber and the receiving space, and a plurality of second through holes formed through the second partition plate and communicating with the second liquid chamber and the receiving space. The switching membrane comprises: an annular plate portion having an inner peripheral edge radially opposed to the inner peripheral wall surface of the accommodation space over the entire circumference, and sandwiched between the first partition plate and the second partition plate in a manner that the inner peripheral edge side protrudes into the accommodation space; and a pair of cylindrical valve portions, which protrude from the entire circumference of the inner peripheral edge of the plate portion toward both sides in the plate thickness direction of the plate portion, respectively; In the communicating state, the valve portion is separated from the inner peripheral wall surface. In the cut-off state, the valve portion deformed radially inward contacts the inner peripheral wall surface to cut off the throttle hole. On the inner peripheral surface of the switching membrane including the inner peripheral edge and the inner peripheral surface of the valve portion, an inclined surface inclined radially outward toward the center of the plate portion in the plate thickness direction is formed at least at a position including the inner peripheral edge.

9. The liquid-filled anti-vibration device according to claim 8, characterized in that: The inner peripheral surface of the valve portion is formed by the inclined surface, and the outer peripheral surface of the valve portion is inclined along the inclined surface.

10. The liquid-filled anti-vibration device according to claim 9, characterized in that: A recessed portion recessed radially outward is formed on the inner peripheral edge side of the inclined surface.

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