Liquid-sealed vibration isolation device

Abstract

To provide a liquid sealed cylinder vibration control device having a new structure which can achieve desired performance with a simple structure having a small number of components and a small number of manufacturing processes.SOLUTION: In a liquid-sealed cylinder vibration control device 10, an inner shaft member 16 and a cylinder part 40 of an intermediate sleeve 18 are connected by a main rubber elastic body 20. The cylinder part 40 is assembled to an outer cylinder member 14 in an insertion state. Further, liquid chambers 64, 64 formed at the main rubber elastic body 20 communicate with each other through an orifice passage 66. The intermediate sleeve 18 made of a synthetic resin is formed in a circumferential direction two piece structure comprising sleeve split bodies 22a, 22b. One axial end of the cylinder part 40 includes an outer flange 42. The cylinder part 40 of the intermediate sleeve 18 in which an outer periphery rubber 50 is fastened to an outer peripheral surface is assembled to the outer cylinder member 14 in a press-fitting manner. An orifice groove 52 formed at the outer periphery rubber 50 is covered with the outer cylinder member 14 to form the orifice passage 66.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a liquid-sealed cylindrical vibration isolator used for a power unit mount of an automobile, a sub-frame mount, etc.

Background Art

[0002] Conventionally, there are known cylindrical vibration isolators applied to a power unit mount that supports a power unit including an engine, a motor, etc. of an automobile, a sub-frame mount that vibrationally connects a sub-frame and a vehicle body, a suspension bushing that vibrationally connects a suspension arm and a vehicle body, etc. Further, as a kind of cylindrical vibration isolator, a liquid-sealed cylindrical vibration isolator that utilizes a vibration isolation action based on the flow action of a liquid enclosed inside, like the liquid-sealed bushing disclosed in Japanese Patent Application Laid-Open No. 2016-133181 (Patent Document 1), is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document Ⅰ

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, as shown in Patent Document 1, the liquid-sealed cylindrical vibration isolator has a structure in which an inner shaft member and an intermediate sleeve are connected by a main body rubber elastic body. In such a structure, in order to reduce or eliminate the tensile stress due to the thermal shrinkage of the main body rubber elastic body after vulcanization molding, it is necessary to reduce the diameter of the intermediate sleeve after molding the main body rubber elastic body to apply radial pre-compression to the main body rubber elastic body.

[0005] Furthermore, the liquid-sealed cylinder type vibration damping device is formed by inserting a separate orifice member into the window portion of the intermediate sleeve, and then fitting an outer cylinder member onto the intermediate sleeve. Since an orifice passage is formed between the overlapping surfaces of the outer cylinder member and the orifice member, it is necessary that the overlapping surfaces of the outer cylinder member and the orifice member be sealed liquid-tight. Therefore, a sealing rubber layer is formed on the inner circumferential surface of the outer cylinder member, and the outer cylinder member is reduced in diameter while it is externally fitted onto the intermediate sleeve and the orifice member, so that the outer cylinder member is overlapped with the outer circumferential surface of the orifice member in a tightly adhering state via the sealing rubber layer.

[0006] Thus, in conventional liquid-sealed cylinder-type vibration isolation devices, it was necessary to perform diameter reduction processing on both the intermediate sleeve and the outer cylinder member, resulting in a large number of manufacturing steps. Furthermore, it was necessary to assemble an orifice member between the intermediate sleeve and the outer cylinder member, which also increased the number of parts.

[0007] The problem to be solved by the present invention is to provide a novel liquid-sealed cylinder type vibration isolation device that can achieve the desired performance with a simple structure with a small number of parts and a small number of manufacturing steps. [Means for solving the problem]

[0008] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0009] The first embodiment is a liquid-sealed cylindrical vibration damping device in which an inner shaft member and a cylindrical portion of an intermediate sleeve are connected by a main rubber elastic body, the cylindrical portion of the intermediate sleeve is assembled in an inserted state to an outer cylindrical member, a pair of liquid chambers are formed in the main rubber elastic body, and an orifice passage is provided that connects the pair of liquid chambers to each other, wherein the intermediate sleeve, made of synthetic resin, is a divided structure that is divided into two in the circumferential direction, consisting of a pair of sleeve divided bodies, the intermediate sleeve has an outer flange at one end in the axial direction of the cylindrical portion, outer rubber is fixed to the outer circumferential surface of the cylindrical portion of the intermediate sleeve, the cylindrical portion to which the outer rubber is fixed is press-fitted into the outer cylindrical member and assembled, and an orifice groove formed in the outer rubber is covered by the outer cylindrical member to form the orifice passage.

[0010] According to this embodiment, the intermediate sleeve has a two-part structure composed of a pair of sleeve divisions. Therefore, if the main rubber elastic body is formed with a gap between the sleeve divisions, for example, the tensile stress acting on the main rubber elastic body is reduced or avoided due to the mutual approach displacement of the sleeve divisions during thermal contraction of the main rubber elastic body. Consequently, there is no need to perform diameter reduction processing on the intermediate sleeve after molding the main rubber elastic body, and the number of manufacturing steps can be reduced.

[0011] An orifice groove is formed in the outer rubber fixed to the outer surface of the cylindrical portion of the intermediate sleeve, and the opening of the orifice groove is covered by the outer cylindrical member, thereby forming an orifice passage. Therefore, a separate part (orifice forming member) for forming the orifice passage is not required, which reduces the number of parts and simplifies the assembly work of the outer cylindrical member to the intermediate sleeve. Note that the orifice groove only needs to be formed using the outer rubber and open on the surface of the outer rubber; for example, the bottom surface of the orifice groove may be formed by the intermediate sleeve.

[0012] By eliminating the need for a separate orifice-forming component, the intermediate sleeve can be press-fitted into the outer cylindrical member. Therefore, the intermediate sleeve and the outer cylindrical member can be fixed to each other without reducing the diameter of the outer cylindrical member. In addition, the outer rubber fixed to the outer surface of the intermediate sleeve is pressed against the inner surface of the outer cylindrical member, sealing the wall of the orifice passage, thus preventing performance degradation due to liquid leakage in the orifice passage.

[0013] The intermediate sleeve has a complex shape due to the irregularities on the outer surface to which the outer rubber is fixed, and the window portion for forming the liquid chamber, making it difficult to form the outer flange if it is made of metal as in the conventional method. In this embodiment, the intermediate sleeve is a molded product made of synthetic resin, so even if it has a complex shape with irregularities on the outer surface, the outer flange can be easily formed. Furthermore, since the intermediate sleeve has a two-part structure and does not require diameter reduction processing after molding of the main rubber elastic body, even if the intermediate sleeve is provided with an outer flange, the outer flange does not interfere with diameter reduction processing.

[0014] The second embodiment is a liquid-sealed cylinder-type vibration isolation device described in the first embodiment, wherein the outer cylinder member is composed of a single metal fitting to which rubber is not fixed.

[0015] According to this embodiment, compared to the conventional structure in which the outer cylindrical member was a rubber vulcanized molded body equipped with sealing rubber and stopper rubber, the structure of the outer cylindrical member is simplified and manufacturing is made easier by omitting the rubber vulcanization molding process.

[0016] The third embodiment is a liquid-sealed cylinder-type vibration damping device as described in the second embodiment, wherein a stopper rubber protruding in the axial direction toward the opposite side of the cylindrical portion is fixed to one axial surface of the outer flange, and a contact rubber interposed between the outer flange and the outer cylindrical member in the axial direction is fixed to the other axial surface of the outer flange.

[0017] According to this embodiment, since the outer flange to which the stopper rubber and the contact rubber are fixed is provided on the intermediate sleeve rather than the outer cylindrical member, it is possible to achieve an axial stopper including the stopper rubber, and cushioning contact between the intermediate sleeve and the outer cylindrical member via the contact rubber, while the outer cylindrical member is a metal fitting without rubber fixed to it.

[0018] The fourth embodiment is a liquid-sealed cylindrical vibration isolation device described in any one of the first to third embodiments, wherein the cylindrical portion of the intermediate sleeve has a thicker wall in the axial middle portion than in the portions at both ends.

[0019] According to this embodiment, when using an intermediate sleeve made of synthetic resin, which tends to have lower strength compared to metal, the strength (durability) of the intermediate sleeve can be improved by making the axial intermediate portion fixed to the main rubber elastic body in the cylindrical portion a thick-walled portion. Furthermore, it is possible to form grooves for forming orifice passages in the intermediate sleeve by utilizing the thick-walled portion. That is, in this embodiment, for example, an orifice passage and a window portion connecting the end of the orifice passage to the liquid chamber can be formed in the thick-walled portion of the intermediate sleeve.

[0020] The fifth embodiment is a liquid-sealed cylindrical vibration isolation device described in any one of the first to fourth embodiments, wherein a pair of window portions are provided that penetrate the cylindrical portion of the intermediate sleeve, and the pair of liquid chambers are configured to include the pair of window portions, and a circumferential extension portion is provided at at least one axial end of the window portion, extending inward from the circumferential edge of the window portion, and a part of the orifice groove is formed in the circumferential extension portion.

[0021] According to this embodiment, by providing a circumferential extension portion in the intermediate sleeve, the area formed solely by the outer rubber on the wall of the orifice passage is narrowed, thereby reducing pressure loss due to deformation of the wall of the orifice passage, and thus enabling efficient fluid flow through the orifice passage.

[0022] The sixth aspect is the liquid-sealed cylindrical vibration isolator described in the fifth aspect, in which the circumferential extension portions are provided on both axial sides of the window portion, respectively.

[0023] According to this aspect, for example, when forming an orifice passage extending on both axial sides of the window portion, the deformation rigidity of the wall portion of the orifice passage is increased in a longer range, and the vibration isolation effect by the orifice passage is improved.

[0024] The seventh aspect is the liquid-sealed cylindrical vibration isolator described in any one of the first to sixth aspects, in which the gap between the circumferential end faces of the pair of sleeve split bodies in the intermediate sleeve is reduced by the compression of the main body rubber elastic body accompanying the press-fitting assembly of the intermediate sleeve to the outer cylinder member.

[0025] According to this aspect, when the pair of sleeve split bodies are press-fitted and assembled to the outer cylinder member, the pair of sleeve split bodies approach and displace relative to each other, so that pre-compression is exerted on the main body rubber elastic body. Therefore, when the main body rubber elastic body is deformed during vibration input, the tensile stress acting on the main body rubber elastic body is reduced, and the durability of the main body rubber elastic body is improved.

[0026] <00000九3>The eighth aspect is the liquid-sealed cylindrical vibration isolator described in any one of the first to seventh aspects, in which a positioning projection protruding to the outer periphery and axially facing the outer flange is provided at the other axial end of the cylindrical portion of the intermediate sleeve, and the outer cylinder member is assembled to the intermediate sleeve between the outer flange and the positioning projection in the axial direction, and the outer cylinder member is axially positioned with respect to the intermediate sleeve.

[0027] According to this aspect, the outer cylinder member is positioned and assembled at an appropriate axial position with respect to the intermediate sleeve. For example, the orifice groove of the outer rubber is surely covered by the outer cylinder member, and short-circuit leakage of the liquid in the orifice passage is prevented.

Advantages of the Invention

[0028] According to the present invention, the desired performance can be achieved in a liquid-sealed cylinder type vibration isolation device through a simple structure with a small number of parts and a small number of manufacturing steps. [Brief explanation of the drawing]

[0029] [Figure 1] This is a cross-sectional view showing a member mount as a first embodiment of the present invention, corresponding to cross-section II in Figure 2. [Figure 2] Section II-II in Figure 1 [Figure 3] Front view of the integrally vulcanized molded part constituting the member mount shown in Figure 1. [Figure 4] Plan view of the integrally vulcanized product shown in Figure 3. [Figure 5] Bottom view of the integrally vulcanized product shown in Figure 3. [Figure 6] Left side view of the integrally vulcanized product shown in Figure 3. [Figure 7] Left side view of the integrally vulcanized product shown in Figure 3. [Figure 8] Figure 3, section VIII-VIII [Figure 9] Figure 3, section IX-IX [Figure 10] Cross-sectional view of XX in Figure 3 [Figure 11] Figure 8, section XI-XI [Figure 12] Figure 7 shows the cross-sectional view between XII and XII. [Figure 13] Perspective view of the sleeve segment that constitutes the integrally vulcanized product shown in Figure 3. [Figure 14] A perspective view showing the sleeve division shown in Figure 13 from a different angle. [Figure 15] Front view of the sleeve division shown in Figure 13. [Figure 16] Plan view of the sleeve division shown in Figure 13. [Figure 17] Figure 13 shows the bottom view of the sleeve division. [Figure 18] Right side view of the sleeve division shown in Figure 13. [Figure 19] Figure 15: Cross-sectional view between XIX-XIX [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described below with reference to the drawings.

[0031] Figures 1 and 2 show a member mount 10 for an automobile as a first embodiment of a liquid-sealed cylinder type vibration damping device with a structure according to the present invention. The member mount 10 has a structure in which an outer cylindrical member 14 is attached to an integrally vulcanized molded product 12. As shown in Figures 3 to 12, the integrally vulcanized molded product 12 has a structure in which an inner shaft member 16 and an intermediate sleeve 18 are elastically connected by a main rubber elastic body 20. In the following description, as a general rule, the vertical direction refers to the vertical direction in Figure 1, the front-rear direction refers to the left-right direction in Figure 1, and the left-right direction refers to the left-right direction in Figure 2.

[0032] As shown in Figures 1, 2, 8 to 12, the inner shaft member 16 is a small-diameter cylindrical member that extends linearly in the front-rear direction with a substantially constant cross-sectional shape. The inner shaft member 16 is a rigid member made of metal, synthetic resin, or the like. As shown in Figure 3, both the inner and outer circumferential surfaces of the inner shaft member 16 have an oval cross-section, and the long axis direction of the inner circumferential surface and the long axis direction of the outer circumferential surface are mutually perpendicular. However, for example, at least one of the inner and outer circumferential surfaces of the inner shaft member may be circular, or it may be a non-circular shape such as a polygon.

[0033] An intermediate sleeve 18 is positioned on the outer circumference of the inner shaft member 16, as shown in Figures 8 to 12. The intermediate sleeve 18 is a molded product made of a synthetic resin such as polyamide. The intermediate sleeve 18 has a divided structure composed of a pair of sleeve divisions 22a and 22b. The sleeve division 22 is generally semi-cylindrical in shape, as shown in Figures 13 to 19, and a flange-like portion 26 projecting outward is integrally formed at one axial end of the semi-cylindrical portion 24. Although Figures 13 to 19 show the upper sleeve division 22a, the lower sleeve division 22b has a common structure obtained by rotating the upper sleeve division 22a by 180°, so the explanation of the upper sleeve division 22a will be explained, and the explanation of the lower sleeve division 22b will be omitted.

[0034] A window portion 28 is formed in the semi-cylindrical portion 24, penetrating radially. The window portion 28 is approximately rectangular in shape when viewed in the vertical direction. The window portion 28 is formed in the central part of the semi-cylindrical portion 24 in both the circumferential and axial directions. In the circumferential direction, the window portion 28 extends over a length of approximately one-third of the circumference of the semi-cylindrical portion 24.

[0035] The axial middle portion of the semi-cylindrical section 24 is a thick-walled section 30 with a larger radial thickness. The thick-walled section 30 is provided on both outer sides in the circumferential direction relative to the window section 28, and is thicker inward than the axial ends. A circumferential groove 32 is formed in the thick-walled section 30 of the semi-cylindrical section 24, opening to the outer surface and extending in the circumferential direction. The circumferential groove 32 is formed at both axial ends of the thick-walled section 30. The circumferential groove 32 is formed in the thick-walled sections 30a and 30b on both sides in the circumferential direction relative to the window section 28. One end of the circumferential groove 32 opens to the circumferential end face of the semi-cylindrical section 24, and the other end opens circumferentially toward the window section 28.

[0036] Circumferential extensions 34 are provided at the four corners of the window portion 28, extending inward from the circumferential edge of the window portion 28. The circumferential extensions 34 extend circumferentially with a roughly L-shaped cross-section, as shown in Figures 16 and 19. Due to the provision of the circumferential extensions 34, as shown in Figure 16, the circumferential groove 32 extends circumferentially inward beyond both circumferential ends of the window portion 28, thus extending the circumferential groove 32. The curvature of the inner circumference of the circumferential extension 34 differs from the curvature of the inner circumference of the thickened portion 30, as shown in Figure 15. The inward projection dimensions of the circumferential extensions 34 are smaller than the inward projection dimensions of the thickened portion 30, thereby adjusting the vertical and horizontal spring ratios of the main rubber elastic body 20, which will be described later. In this embodiment, the circumferential extensions 34 are provided on both sides of the window portion 28 in the axial direction, but they may also be provided on only one side in the axial direction. Furthermore, although the circumferential extensions 34 are provided on both sides of the window portion 28 in the circumferential direction in this embodiment, they may also be provided on only one side in the circumferential direction. As can be seen from these points, the number of circumferential extensions 34 is not particularly limited, and it is not necessarily required that four circumferential extensions 34 be provided.

[0037] As shown in Figures 16 and 19, the thickened portions 30a and 30b provided on both sides of the window portion 28 in the circumferential direction have a longitudinal groove 36 formed in only one of the thickened portions 30b, and the circumferential grooves 32, 32 on both sides in the axial direction are interconnected by the longitudinal groove 36. The longitudinal groove 36 is provided in the thickened portion 30 at a position close to the window portion 28 in the circumferential direction and extends linearly in the axial direction.

[0038] In this way, by forming circumferential grooves 32, 32 and longitudinal grooves 36 in the thickened portion 30 located in the axial middle of the semi-cylindrical portion 24, it is possible to prevent the semi-cylindrical portion 24 from becoming excessively thin in the portion where the circumferential grooves 32, 32 and longitudinal grooves 36 are formed, thereby ensuring the strength of the semi-cylindrical portion 24.

[0039] A flange-like portion 26 is integrally formed at one axial end (front end) of the semi-cylindrical portion 24 and protrudes outward. The flange-like portion 26 has a semicircular plate shape that extends approximately halfway around the circumference. The circumferential length of the flange-like portion 26 is approximately the same as the circumferential length of the semi-cylindrical portion 24.

[0040] A positioning projection 38 is integrally formed on the other axial end (rear end) of the semi-cylindrical portion 24. The positioning projection 38 protrudes outward from the rear end of the semi-cylindrical portion 24 and faces the flange-like portion 26 in the axial direction. The positioning projection 38 has a smaller circumferential length than the flange-like portion 26 and is provided in the central circumferential portion of the semi-cylindrical portion 24, away from both circumferential ends. In this embodiment, the circumferential length of the axial rear end of the semi-cylindrical portion 24 on which the positioning projection 38 is provided is also shortened, thus shortening the axial length of the semi-cylindrical portion 24 at both circumferential ends.

[0041] A cylindrical intermediate sleeve 18 is formed by combining a pair of sleeve divisions 22a and 22b facing each other. In the intermediate sleeve 18, the circumferential end faces of the sleeve divisions 22a and 22b face each other in the circumferential direction, and the overall cylindrical tubular portion 40 is composed of semi-cylindrical portions 24 and 24, while the overall annular plate-shaped outer flange 42 is composed of flange-like portions 26 and 26. The intermediate sleeve 18 has a pair of window portions 28 and 28 formed in the vertically opposing portions.

[0042] The circumferential grooves 32 on the axial front side of the sleeve divisions 22a and 22b are interconnected in the circumferential direction, and the window portions 28, 28 of the sleeve divisions 22a and 22b are interconnected on both sides in the circumferential direction. Similarly, the circumferential grooves 32 on the axial rear side of the sleeve divisions 22a and 22b are interconnected in the circumferential direction, and the window portions 28, 28 of the sleeve divisions 22a and 22b are interconnected on both sides in the circumferential direction.

[0043] As shown in Figures 8 to 12, the intermediate sleeve 18 is externally mounted on the inner shaft member 16, spaced apart on the outer circumference, and the inner shaft member 16 and the intermediate sleeve 18 are interconnected by the main rubber elastic body 20. The main rubber elastic body 20 is substantially cylindrical in shape overall, with its inner circumferential surface vulcanized and bonded to the inner shaft member 16, and its outer circumferential surface vulcanized and bonded to the intermediate sleeve 18. The main rubber elastic body 20 is formed as an integrally vulcanized molded product 12 comprising the inner shaft member 16 and the intermediate sleeve 18.

[0044] Because the intermediate sleeve 18 has a segmented structure consisting of a pair of sleeve segments 22a and 22b, even if the main rubber elastic body 20 shrinks in the direction perpendicular to the axis due to cooling after molding (thermal shrinkage), the sleeve segments 22a and 22b move toward each other, thereby reducing the tensile strain of the main rubber elastic body 20. Therefore, there is no need to perform diameter reduction processing on the intermediate sleeve 18 after molding the main rubber elastic body 20, which simplifies manufacturing, shortens manufacturing time, and reduces manufacturing costs by omitting the diameter reduction processing step. When setting the sleeve segments 22a and 22b in the molding die for the main rubber elastic body 20, it is desirable to set a predetermined gap between the sleeve segments 22a and 22b, taking into account the displacement of the sleeve segments 22a and 22b moving toward each other due to the thermal shrinkage of the main rubber elastic body 20. As a result, a part of the main rubber elastic body 20 is interposed between the sleeve segments 22a and 22b. Furthermore, it is desirable that a predetermined gap be provided between the sleeve segments 22a and 22b after the main rubber elastic body 20 has undergone thermal shrinkage.

[0045] As shown in Figures 8 to 10, the main rubber elastic body 20 is provided with a first groove 44 opening on one axial end face (front end face) and a second groove 46 opening on the other axial end face (rear end face). The size, including the cross-sectional shape and depth of each groove 44, 46, is not particularly limited and can be set appropriately according to the required characteristics.

[0046] The main rubber elastic body 20 is provided with a pair of recesses 48, 48. As shown in Figures 8 and 11, the recesses 48, 48 are provided on both the upper and lower sides of the inner shaft member 16 and open to the upper and lower sides on the outer circumferential surface of the main rubber elastic body 20. The recesses 48, 48 are aligned with the windows 28, 28 of the intermediate sleeve 18 and are open to the outer circumferential side through the windows 28, 28.

[0047] An outer periphery rubber 50 is fixed to the outer circumferential surface of the cylindrical portion 40 in the intermediate sleeve 18. The outer periphery rubber 50 is integrally formed with the main rubber elastic body 20. The outer periphery rubber 50 is positioned in front of the positioning projection 38 in the axial direction, so that the positioning projection 38 is exposed and not covered by the outer periphery rubber 50.

[0048] As shown in Figures 4 to 7, the outer circumferential rubber 50 is fixed to the outer circumferential surface of the cylindrical portion 40 of the intermediate sleeve 18, so that the circumferential groove 32 and the longitudinal groove 36 are appropriately filled with the outer circumferential rubber 50, and an orifice groove 52 is formed that extends in the circumferential direction for a length exceeding one full turn and connects a pair of recesses 48, 48 to each other. As shown in Figures 4 and 5, both ends of the orifice groove 52 extend inward in the axial direction and are connected to the circumferential central portion of the recesses 48, 48. A part of the orifice groove 52 is formed in the circumferential extension portion 34 which constitutes a part of the circumferential groove 32.

[0049] In the outer circumference rubber 50, a seal lip 54 protruding outward is continuously formed along the entire circumference in the portion located axially outward from the circumferential groove 32. The seal lip 54 has a tapered cross-sectional shape and protrudes outward. In this embodiment, two seal lips 54, 54 are provided in parallel and spaced apart from each other in front of the front circumferential grooves 32, 32, and two seal lips 54, 54 are provided in parallel and spaced apart from each other behind the rear circumferential grooves 32, 32.

[0050] The outer flange 42 is covered by a covering rubber 56 that is integrally formed with the main rubber elastic body 20 and the outer peripheral rubber 50. As shown in Figures 3 to 8, the outer flange 42 is partially exposed from the covering rubber 56 at multiple locations in the circumferential direction.

[0051] The covering rubber 56 includes a contact rubber 58 that covers the rear surface of the outer flange 42. In addition, the portion of the covering rubber 56 that covers the front surface of the outer flange 42 is provided with a plurality of stopper rubbers 60 that protrude forward. The stopper rubbers 60 are fixed to the front surface of the outer flange 42, are roughly square block-shaped, and have a tapered shape that narrows towards the protruding tip. In this embodiment, eight stopper rubbers 60 are provided spaced apart from each other in the circumferential direction. The stopper rubbers 60 include stopper rubbers 60a with a large axial projection area and a small protruding height, and stopper rubbers 60b with a small axial projection area and a large protruding height, and these stopper rubbers 60a and stopper rubbers 60b are arranged alternately in the circumferential direction.

[0052] As shown in Figures 1 and 2, an outer cylindrical member 14 is attached to the intermediate sleeve 18 of the integrally vulcanized molded product 12. The outer cylindrical member 14 is cylindrical in shape overall and has a flange portion 62 that protrudes outward at its front end. In this embodiment, the outer cylindrical member 14 is made of metal, but it may also be made of synthetic resin, for example. The outer cylindrical member 14 is not made of rubber and is a single component made of metal or synthetic resin, and in this embodiment it is a single metal fitting.

[0053] An intermediate sleeve 18, covered with an outer rubber 50, is assembled to the outer cylindrical member 14 in an inserted state. By assembling the outer cylindrical member 14 to the intermediate sleeve 18, the inner shaft member 16 and the outer cylindrical member 14 are connected by the main rubber elastic body 20.

[0054] The cylindrical portion 40 of the intermediate sleeve 18 is press-fitted into the inner circumference of the outer cylindrical member 14 via an outer rubber 50, and the outer rubber 50 is compressed radially between the cylindrical portion 40 and the outer cylindrical member 14. The outer cylindrical member 14 is positioned axially relative to the intermediate sleeve 18 by having its flange portion 62 overlap the outer flange 42 of the intermediate sleeve 18 via a contact rubber 58. The presence of the contact rubber 58 between the outer flange 42 of the intermediate sleeve 18 and the flange portion 62 of the outer cylindrical member 14 absorbs tolerances and other errors in the dimensions of the parts by the deformation of the contact rubber 58, allowing the intermediate sleeve 18 and the outer cylindrical member 14 to be assembled in the appropriate relative position in the axial direction, and preventing damage caused by direct contact between the outer flange 42 and the flange portion 62.

[0055] In this embodiment, in the integrally vulcanized molded product 12, the opposing surfaces of the circumferential end faces of the sleeve divisions 22a and 22b are separated from each other, and the distance between the opposing surfaces of the circumferential end faces of the sleeve divisions 22a and 22b is reduced by press-fitting the intermediate sleeve 18 into the outer cylindrical member 14. Therefore, the main rubber elastic body 20 is compressed in the direction perpendicular to the axis by press-fitting the intermediate sleeve 18 into the outer cylindrical member 14, further reducing the tensile strain of the main rubber elastic body 20 when vibration is input, thereby improving durability. Furthermore, since the opposing direction of the circumferential end faces of the sleeve divisions 22a and 22b is the vertical direction, which is the main vibration input direction, the main rubber elastic body 20 is pre-compressed in the vertical direction, improving durability against the main vibration input.

[0056] When the intermediate sleeve 18 and the outer cylindrical member 14 are positioned by overlapping the outer flange 42 and the flange portion 62, the outer cylindrical member 14 is prevented from coming off the intermediate sleeve 18 backward by the locking of the rear surface of the outer cylindrical member 14 with the positioning projection 38. In other words, the outer cylindrical member 14 is assembled to the cylindrical portion 40 of the intermediate sleeve 18 between the axially opposing surfaces of the outer flange 42 and the positioning projection 38, and is positioned axially relative to the intermediate sleeve 18. As a result, the outer cylindrical member 14 is held in an externally fitted state relative to the intermediate sleeve 18, and axial misalignment between the intermediate sleeve 18 and the outer cylindrical member 14 is limited.

[0057] A pair of liquid chambers 64, 64 are formed by covering the openings of the recesses 48, 48 in the main rubber elastic body 20 with the outer cylindrical member 14. The liquid chambers 64 are provided in the window portions 28, 28 and are composed of the main rubber elastic body 20, with the wall portion including the portion that covers the inner circumferential surface of the window portions 28, 28. Internal pressure fluctuations are induced by the deformation of the main rubber elastic body 20. Liquids such as water, ethylene glycol, silicone oil, or mixtures thereof are sealed in the liquid chambers 64. The sealed fluid is not limited to those exemplified, but is preferably an incompressible liquid. Furthermore, it is desirable that the sealed fluid be a low-viscosity liquid.

[0058] The outer periphery opening of the orifice groove 52 formed in the outer rubber 50 is covered by the outer cylindrical member 14, thereby forming an orifice passage 66 that connects the two liquid chambers 64, 64 to each other. When vibration is input, the relative internal pressure fluctuations of the liquid chambers 64, 64 cause liquid to flow between the liquid chambers 64, 64 through the orifice passage 66, and a vibration isolation effect based on the action of liquid flow is exhibited. Preferably, the resonance frequency (tuning frequency) of the flowing liquid in the orifice passage 66 is adjusted to the frequency of the vibration to be isolated.

[0059] In this embodiment, the orifice groove 52 is formed using the circumferential groove 32 formed in the intermediate sleeve 18, and no separate orifice-forming member is provided from the intermediate sleeve 18. Therefore, the intermediate sleeve 18 can be assembled to the outer cylindrical member 14 by rubber press-fitting, and there is no need to reduce the diameter of the outer cylindrical member 14 while it is externally fitted to the intermediate sleeve 18 and then fit and fix it in place. Therefore, the process of reducing the diameter of the outer cylindrical member 14 is omitted, leading to easier manufacturing, reduced manufacturing costs, and a simplified structure.

[0060] The circumferential groove 32 provided in the intermediate sleeve 18 has a long circumferential length due to the circumferential extension portion 34, and the area formed solely of rubber outside the circumferential groove 32 at the wall portion of the orifice groove 52 (orifice passage 66) is narrowed. As a result, deformation of the wall portion of the orifice passage 66 due to the action of hydraulic pressure is suppressed, and the vibration damping effect due to fluid flow through the orifice passage 66 is stably exerted.

[0061] Furthermore, the opening edges of the recesses 48, 48 and the opening edge of the orifice groove 52 are all made of outer rubber 50, and the inner surface of the outer cylindrical member 14 is pressed against the outer rubber 50, so that the openings of the recesses 48, 48 and the opening of the orifice groove 52 are liquid-tightly covered by the outer cylindrical member 14.In this embodiment, the liquid-filled region is set in the axial central part, and seal lips 54 are provided on both axial outer sides of the liquid-filled region.As a result, when the intermediate sleeve 18 is press-fitted into the outer cylindrical member 14, the seal lips 54 are pressed against the inner surface of the outer cylindrical member 14 to form a seal structure, thereby more reliably preventing liquid leakage outward in the axial direction from the liquid-filled region.

[0062] The member mount 10, for example, has an inner shaft member 16 attached to the vehicle body and an outer cylindrical member 14 attached to the suspension member, thereby providing vibration-damping connectivity between the vehicle body and the suspension member. When vertical vibrations are input to the member mount 10 in this mounted state on the vehicle, a relative pressure difference is generated between the pair of liquid chambers 64, 64, causing fluid flow through the orifice passage 66, and a vibration-damping effect based on the fluid flow action is exerted.

[0063] Furthermore, a vehicle body-side member (not shown) attached to the inner shaft member 16 is provided with a stopper receiving portion that faces axially forward relative to the outer flange 42 of the intermediate sleeve 18. The stopper receiving portion and the outer flange 42 come into contact via the stopper rubber 60, thereby limiting the amount of axial forward displacement of the inner shaft member 16 relative to the outer cylindrical member 14, and improving durability by limiting the amount of deformation of the main rubber elastic body 20.

[0064] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the pair of sleeve divisions constituting the intermediate sleeve are not necessarily limited to having the same shape as each other, and can be combined if they have different shapes.

[0065] The cross-sectional area, cross-sectional shape, and path of the orifice passage are not particularly limited and can be appropriately changed and set according to, for example, the frequency of the vibration to be isolated. Furthermore, multiple orifice passages may be provided. When multiple orifice passages are formed, the tuning frequencies of these orifice passages may be the same or different. [Explanation of symbols]

[0066] 10. Member mount (Liquid-sealed cylinder type vibration isolation device, first embodiment) 12 One-piece vulcanized molded product 14 Outer cylindrical member 16 Inner shaft member 18 intermediate sleeves 20 Main body rubber elastic body 22(22a,22b) Sleeve division 24 Semi-cylindrical section 26 Flange-shaped part 28 Window section 30(30a,30b) Thick wall part 32 Circumferential groove 34 Circumferential extension part 36 vertical grooves 38 Positioning protrusions 40 Cylindrical part 42 Outer flange 44 First Straight Groove 46. ​​The second spur groove 48. Recess 50 Outer circumference rubber 52 Orifice groove 54 Seal Lip 56 Covered rubber 58 Contact rubber 60 (60a, 60b) Stopper rubber 62 Flange section 64 Liquid chamber 66 Orifice Passage

Claims

1. A liquid-sealed cylindrical vibration damping device is provided in which an inner shaft member and a cylindrical portion of an intermediate sleeve are connected by a main rubber elastic body, the cylindrical portion of the intermediate sleeve is assembled in an inserted state to an outer cylindrical member, a pair of liquid chambers are formed in the main rubber elastic body, and an orifice passage is provided that connects the pair of liquid chambers to each other, The aforementioned intermediate sleeve, made of synthetic resin, has a circumferentially divided structure consisting of a pair of sleeve divisions. The intermediate sleeve is provided with an outer flange at one end of the cylindrical portion in the axial direction. The outer surface of the cylindrical portion of the intermediate sleeve is fixed with outer rubber, and the cylindrical portion to which the outer rubber is fixed is press-fitted into the outer cylindrical member and assembled. The orifice groove formed in the outer rubber is covered by the outer cylindrical member, thereby forming the orifice passage. The outer cylindrical member is composed of a single metal fitting to which rubber is not fixed. A stopper rubber protruding axially toward the opposite side of the cylindrical portion is fixed to one axial surface of the outer flange. A liquid-sealed cylinder-type vibration damping device in which a contact rubber interposed between the outer flange and the outer cylindrical member in the axial direction is fixed to the other axial surface of the outer flange.

2. A liquid-sealed cylindrical vibration damping device in which an inner shaft member and a cylindrical portion of an intermediate sleeve are connected by a main rubber elastic body, the cylindrical portion of the intermediate sleeve is assembled in an inserted state to an outer cylindrical member, a pair of liquid chambers are formed in the main rubber elastic body, and an orifice passage is provided that connects the pair of liquid chambers to each other, The aforementioned intermediate sleeve, made of synthetic resin, has a circumferentially divided structure consisting of a pair of sleeve divisions. The intermediate sleeve is provided with an outer flange at one end of the cylindrical portion in the axial direction. The outer surface of the cylindrical portion of the intermediate sleeve is fixed with outer rubber, and the cylindrical portion to which the outer rubber is fixed is press-fitted into the outer cylindrical member and assembled. The orifice groove formed in the outer rubber is covered by the outer cylindrical member, thereby forming the orifice passage. A liquid-sealed cylindrical vibration damping device in which the cylindrical portion of the intermediate sleeve has a thicker wall in the axial middle section than in the end sections.

3. A liquid-sealed cylindrical vibration damping device in which an inner shaft member and a cylindrical portion of an intermediate sleeve are connected by a main rubber elastic body, the cylindrical portion of the intermediate sleeve is assembled in an inserted state to an outer cylindrical member, a pair of liquid chambers are formed in the main rubber elastic body, and an orifice passage is provided that connects the pair of liquid chambers to each other, The aforementioned intermediate sleeve, made of synthetic resin, has a circumferentially divided structure consisting of a pair of sleeve divisions. The intermediate sleeve is provided with an outer flange at one end of the cylindrical portion in the axial direction. The outer surface of the cylindrical portion of the intermediate sleeve is fixed with outer rubber, and the cylindrical portion to which the outer rubber is fixed is press-fitted into the outer cylindrical member and assembled. The orifice groove formed in the outer rubber is covered by the outer cylindrical member, thereby forming the orifice passage. The intermediate sleeve is provided with a pair of windows that penetrate the cylindrical portion, and the pair of liquid chambers are configured to include the pair of windows. At least one axial end of the window portion, a circumferential extension is provided that extends inward from the circumferential edge of the window portion. A liquid-sealed cylinder-type vibration isolation device in which a portion of the orifice groove is formed in the circumferential extension portion.

4. The liquid envelope type vibration isolation device according to claim 3, wherein the circumferential extension portion is provided on both sides of the axial direction of the window portion.

5. A liquid-sealed cylindrical vibration damping device in which an inner shaft member and a cylindrical portion of an intermediate sleeve are connected by a main rubber elastic body, the cylindrical portion of the intermediate sleeve is assembled in an inserted state to an outer cylindrical member, a pair of liquid chambers are formed in the main rubber elastic body, and an orifice passage is provided that connects the pair of liquid chambers to each other, The aforementioned intermediate sleeve, made of synthetic resin, has a circumferentially divided structure consisting of a pair of sleeve divisions. The intermediate sleeve is provided with an outer flange at one end of the cylindrical portion in the axial direction. The outer surface of the cylindrical portion of the intermediate sleeve is fixed with outer rubber, and the cylindrical portion to which the outer rubber is fixed is press-fitted into the outer cylindrical member and assembled. The orifice groove formed in the outer rubber is covered by the outer cylindrical member, thereby forming the orifice passage. A liquid-sealed cylindrical vibration damping device wherein the distance between the circumferential end faces of the pair of sleeve divisions in the intermediate sleeve is reduced by the compression of the main body rubber elastic material accompanying the press-fit assembly of the intermediate sleeve into the outer cylindrical member.

6. A liquid-sealed cylindrical vibration damping device in which an inner shaft member and a cylindrical portion of an intermediate sleeve are connected by a main rubber elastic body, the cylindrical portion of the intermediate sleeve is assembled in an inserted state to an outer cylindrical member, a pair of liquid chambers are formed in the main rubber elastic body, and an orifice passage is provided that connects the pair of liquid chambers to each other, The aforementioned intermediate sleeve, made of synthetic resin, has a circumferentially divided structure consisting of a pair of sleeve divisions. The intermediate sleeve is provided with an outer flange at one end of the cylindrical portion in the axial direction. The outer surface of the cylindrical portion of the intermediate sleeve is fixed with outer rubber, and the cylindrical portion to which the outer rubber is fixed is press-fitted into the outer cylindrical member and assembled. The orifice groove formed in the outer rubber is covered by the outer cylindrical member, thereby forming the orifice passage. The other axial end of the cylindrical portion of the intermediate sleeve is provided with a positioning projection that protrudes outward and faces the outer flange in the axial direction. A liquid-sealed cylindrical vibration damping device in which the outer cylindrical member is assembled to the intermediate sleeve between the outer flange and the positioning projection in the axial direction, and the outer cylindrical member is positioned in the axial direction with respect to the intermediate sleeve.

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