JP2024114177A - Fluid-filled cylindrical vibration isolation device - Google Patents

Abstract

To provide a fluid-sealed cylindrical vibration isolator having a novel structure which can arrange an outer flange-shaped part of an intermediate cylinder metal fixture by exposing it to the outside of an axial direction while easily assembling an outer cylinder metal fixture to the other member, and a manufacturing method of the vibration isolator.SOLUTION: In a fluid-sealed cylindrical vibration isolator 10 in which an outer cylinder metal fixture 14 is externally fit and fixed to a vulcanized molding 12 integrated with a main body rubber elastic body 20 having an inner shaft metal fixture 16 and an intermediate cylinder metal fixture 18, and a fluid chamber 68 is formed, an axial-direction end part of the intermediate cylinder metal fixture 18 is integrally formed with an outer flange-shaped part 22 which protrudes from the outer cylinder metal fixture 14 in an axial direction, and is expanded to an external peripheral side, the outer cylinder metal fixture 14 comprises an attachment cylindrical part 60 attached to the other member 72 having a large-diameter cylindrical external peripheral face larger than an outside diameter of the outer flange-shaped part 22, and the outer cylinder metal fixture 14 has a fitment cylindrical part 62a having a small diameter smaller than an outside diameter of the outer flange-shaped part 22 at the axial-direction end part of the outer flange-shaped part 22, and externally fit and fixed to the axial-direction end part of the intermediate cylinder metal fixture 18.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fluid-filled cylindrical vibration isolation device that is used, for example, in engine mounts, motor mounts, and subframe mounts of automobiles.

Fluid-filled cylindrical vibration-damping devices that are used in engine mounts, motor mounts, subframe mounts, and the like for automobiles have been known for some time. As disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 6-54941 (Patent Document 1), a fluid-filled cylindrical vibration-damping device has a structure in which an outer cylindrical metal fitting is fitted and fixed to an integrally vulcanized molded product in which an inner shaft fitting and an intermediate cylindrical metal fitting are elastically connected by a main rubber elastic body, and a pocket portion that opens onto the outer peripheral surface of the integrally vulcanized molded product is covered by the outer cylindrical metal fitting to form a fluid chamber. With a fluid-filled cylindrical vibration-damping device, a vibration-damping effect is exerted based on the flow action of the fluid sealed in the fluid chamber when vibration is input.

Japanese Utility Model Application Publication No. 6-54941

In the fluid-filled cylindrical vibration-damping device of Patent Document 1, an outer flange-shaped portion that extends outwardly is provided at the axial end of the intermediate cylindrical fitting. In Patent Document 1, the outer cylindrical fitting is fitted over the entire intermediate cylindrical fitting, including the outer flange-shaped portion, and the axial end of the outer cylindrical fitting is bent inwardly and overlapped with the outer flange-shaped portion of the intermediate cylindrical fitting from the axial outside, thereby positioning the intermediate cylindrical fitting and the outer cylindrical fitting in the axial direction.

However, if the axial outer surface of the outer flange portion of the intermediate tubular fitting is covered by the outer tubular fitting, it becomes difficult to, for example, form an axial stopper using the outer flange portion. It is also possible to form a stopper using the axial end portion of the inner flange-shaped outer tubular fitting that is overlaid on the outer flange portion, but in that case, it becomes necessary to vulcanize-mold rubber (stopper rubber) not only on the intermediate tubular fitting but also on the outer tubular fitting, which leads to problems such as an increase in the number of manufacturing steps and an increase in manufacturing costs.

In addition, for example, if the outer tubular fitting is fitted and fixed to the axially middle part of the intermediate tubular fitting so that the outer flange-shaped portion of the intermediate tubular fitting is exposed axially outward, it may be difficult to press-fit the outer tubular fitting into an assembly hole or the like of the other member to which the outer tubular fitting is attached, due to the presence of the outer flange-shaped portion. Also, for example, if the other member is inserted from the outer flange-shaped portion side onto the outer tubular fitting and then reduced in diameter to be fitted and fixed, the other member before being reduced in diameter must be made larger than the outer flange-shaped portion, and the amount of deformation of the other member by reduction in diameter required for fitting and fixing becomes large.

The problem to be solved by the present invention is to provide a fluid-filled cylindrical vibration-damping device with a new structure that allows the outer tubular metal fitting to be easily assembled to other members while exposing the outer flange-like portion of the axial end of the intermediate tubular metal fitting to the axial outside.

Another object of the present invention is to provide a method for manufacturing a novel fluid-filled cylindrical vibration-damping device in which the outer flange-shaped portion of the axial end of the intermediate cylindrical fitting is exposed axially outward while allowing the outer cylindrical fitting to be easily assembled to other members.

The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is merely an example, and may be combined with one another as appropriate. The multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various alternative embodiments may be realized.

The first aspect is a fluid-filled cylindrical vibration-proof device in which an outer tubular metal fitting is fitted and fixed to an integrally vulcanized molded product in which an inner shaft fitting and an intermediate tubular metal fitting are elastically connected by a main rubber elastic body, and a pocket portion opening on the outer circumferential surface of the integrally vulcanized molded product is covered by the outer tubular metal fitting to form a fluid chamber. The axial end of the intermediate tubular metal fitting is integrally formed with an outer flange-shaped portion that protrudes axially from the outer tubular metal fitting and spreads outward, while the outer tubular metal fitting has, in the axial middle portion, a tubular portion for mounting to another member with a tubular outer circumferential surface having a larger diameter than the outer diameter of the outer flange-shaped portion of the intermediate tubular metal fitting, and the outer tubular metal fitting has, at the axial end of the intermediate tubular metal fitting on the outer flange-shaped portion side, a fitting tubular portion with a smaller diameter than the outer diameter of the outer flange-shaped portion that is fitted and fixed to the intermediate tubular metal fitting.

In a fluid-filled cylindrical vibration-damping device constructed according to this embodiment, since an outer flange-shaped portion is provided on the intermediate cylindrical metal fitting, for example, an axial stopper that limits the amount of relative axial displacement between the inner shaft fitting and the outer cylindrical metal fitting can be constructed using the outer flange-shaped portion.

The mounting tubular portion of the outer tubular fitting has a tubular outer peripheral surface with a larger diameter than the outer diameter of the outer flange portion of the intermediate tubular fitting, so even if the intermediate tubular fitting has an outer flange portion, the outer tubular fitting can be easily fixed to another member.

The fitting tubular portion provided at the axial end of the outer flange portion of the outer tubular fitting is made smaller in diameter than the outer diameter of the outer flange portion, which prevents the outer tubular fitting from slipping out of the intermediate tubular fitting toward the outer flange portion, allowing the outer tubular fitting and the intermediate tubular fitting to be stably fixed together.

The second aspect is a fluid-filled cylindrical vibration-damping device as described in the first aspect, in which the outer cylindrical metal fitting is a single metal fitting with no rubber elastic body attached.

A fluid-filled cylindrical vibration-damping device constructed in accordance with this embodiment can reduce the number of molding steps for the rubber elastic body, making manufacturing easier.

The third aspect is a fluid-filled cylindrical vibration-proof device according to the first or second aspect, in which the outer cylindrical metal fitting has an outer flange-shaped outer flange portion that extends outwardly and is integrally formed at the axial end of the intermediate cylindrical metal fitting opposite the outer flange-shaped portion.

With a fluid-filled cylindrical vibration-damping device constructed according to this embodiment, for example, an axial stopper on the opposite side of the outer flange portion can be formed using the outer flange portion, and the outer cylindrical fitting and the intermediate cylindrical fitting can be positioned in the axial direction by abutting the outer flange portion against the intermediate cylindrical fitting.

The fourth aspect is a fluid-filled cylindrical vibration-damping device as described in the third aspect, in which the intermediate cylindrical metal fitting is provided with an outer flange-shaped protruding piece that spreads outwardly at the axial end opposite the outer flange-shaped portion, and the protruding piece overlaps with the outer flange portion of the outer cylindrical metal fitting in the axial direction.

In a fluid-filled cylindrical vibration-damping device constructed according to this embodiment, the protruding piece of the intermediate cylindrical fitting and the outer flange portion of the outer cylindrical fitting are overlapped in the axial direction, so that the intermediate cylindrical fitting and the outer cylindrical fitting are positioned in the axial direction, and the outer cylindrical fitting can be easily attached to the intermediate cylindrical fitting at an appropriate axial position.

For example, the axial stopper on the opposite side to the outer flange portion can be constructed using a protruding piece. In this case, since the axial stoppers on both sides of the axial direction are constructed from the intermediate tubular metal fitting, it is possible to vulcanize the stopper rubber on both sides of the axial direction integrally with the main rubber elastic body, thereby reducing the number of vulcanization molding steps for the rubber.

The fifth aspect is a fluid-filled cylindrical vibration-proof device according to any one of the first to fourth aspects, in which the outer cylindrical metal fitting has, at the axial end opposite the outer flange portion of the intermediate cylindrical metal fitting, another fitted cylindrical portion that is fixed to the outside of the intermediate cylindrical metal fitting and has a smaller diameter than the outer diameter of the outer flange portion.

With a fluid-filled cylindrical vibration-damping device constructed according to this embodiment, the outer cylindrical metal fitting is fixed to the intermediate cylindrical metal fitting at the fitting cylindrical portions provided at both axial ends, making it easier to ensure the fixing strength of the outer cylindrical metal fitting to the intermediate cylindrical metal fitting. Furthermore, since the fixing positions of the outer cylindrical metal fitting to the intermediate cylindrical metal fitting are set on both axial sides of the mounting cylindrical portion, it is possible to effectively prevent the outer cylindrical metal fitting from shifting or deforming due to the assembly reaction force acting on the mounting cylindrical portion when it is assembled to another component.

The sixth aspect is a fluid-filled cylindrical vibration-damping device according to any one of the first to fifth aspects, in which a stopper rubber is fixed to the axial outer surface of the outer flange portion of the intermediate cylindrical metal fitting.

In a fluid-filled cylindrical vibration isolation device constructed according to this embodiment, the outer flange portion is used to form an axial stopper. The stopper rubber attached to the intermediate cylindrical metal fitting can also be formed integrally with the main rubber elastic body.

The seventh aspect is a fluid-filled cylindrical vibration-damping device according to any one of the first to sixth aspects, in which a coating rubber layer is fixed to the outer circumferential surface of the intermediate cylindrical metal fitting, and the portion of the coating rubber layer that covers the outer flange portion protrudes outward beyond the outer flange portion.

With a fluid-filled cylindrical vibration-damping device constructed according to this embodiment, for example, when the other member to which the mounting cylindrical portion of the outer cylindrical fitting is fixed extends to the outer periphery of the outer flange portion of the intermediate cylindrical fitting, the covering rubber layer is pressed against the other member, thereby sealing the gap between the other member and the fluid-filled cylindrical vibration-damping device with the covering rubber layer. This makes it possible to prevent foreign matter such as water or dust from entering between the other member and the fluid-filled cylindrical vibration-damping device.

The eighth aspect is a fluid-filled cylindrical vibration-damping device according to any one of the first to seventh aspects, in which the intermediate cylindrical metal fitting has a mating surface of the mating cylindrical portion of the outer cylindrical metal fitting covered with a seal rubber.

With a fluid-filled cylindrical vibration-damping device constructed according to this embodiment, the gap between the intermediate tubular metal fitting and the mating tubular portion of the outer tubular metal fitting is sealed with a seal rubber, so that leakage of fluid from the fluid chamber can be more reliably prevented. Furthermore, by providing the seal rubber on the mating surface on the intermediate tubular metal fitting side rather than on the outer tubular metal fitting side, it is possible to form the seal rubber integrally with the main rubber elastic body, for example, and to make the outer tubular metal fitting into a single metal fitting.

In the ninth aspect, an outer tubular metal fitting is fitted and fixed to an integrally vulcanized molded product in which an inner shaft fitting and an intermediate tubular metal fitting are elastically connected by a main rubber elastic body, and a pocket portion opening on the outer circumferential surface of the integrally vulcanized molded product is covered by the outer tubular metal fitting to form a fluid chamber. In this case, the intermediate tubular metal fitting is used, which is integrally formed with an outer flange-like portion that protrudes in the axial direction from the outer tubular metal fitting at the axial end and spreads outward toward the outer circumferential side, and the outer flange-like portion is fixed to the intermediate tubular metal fitting of the integrally vulcanized molded product. This is a method of manufacturing a fluid-filled cylindrical vibration-proof device in which the outer cylindrical fitting, whose inner diameter is larger than the outer diameter, is inserted from the outer flange side, and the outer cylindrical fitting is subjected to a diameter reduction process to form a cylindrical portion for mounting to another member in the axially middle portion of the outer cylindrical fitting, which has a cylindrical outer circumferential surface with a diameter larger than the outer diameter of the outer flange portion of the intermediate cylindrical fitting, and fitting cylindrical portions with a diameter smaller than the outer diameter of the outer flange portion of the intermediate cylindrical fitting and fixed to the outer surface of the intermediate cylindrical fitting are formed on both axial sides of the mounting cylindrical portion of the outer cylindrical fitting.

According to the manufacturing method of the fluid-filled cylindrical vibration-damping device according to this embodiment, even if an outer flange-shaped portion is provided at the axial end of the intermediate cylindrical fitting, the outer cylindrical fitting can be fixed to the intermediate cylindrical fitting by inserting the outer cylindrical fitting from the outer flange-shaped portion side onto the intermediate cylindrical fitting and forming a fitting cylindrical portion on the outer cylindrical fitting by diameter reduction processing. Furthermore, by forming a mounting cylindrical portion on the outer cylindrical fitting that is larger in diameter than the outer flange-shaped portion by diameter reduction processing, the outer cylindrical fitting can be easily fixed to another member from the outer flange-shaped portion side.

According to the present invention, the outer tubular fitting can be easily assembled to other members, while the outer flange-shaped portion at the axial end of the intermediate tubular fitting can be exposed axially outward.

FIG. 4 is a cross-sectional view showing a fluid-filled cylindrical vibration-damping device according to a first embodiment of the present invention, which corresponds to the II cross section of FIG. FIG. 2 is a cross-sectional view of the fluid-filled cylindrical vibration-damping device shown in FIG. 1, which corresponds to the cross-section II-II of FIG. 3 is a cross-sectional view taken along line III-III of FIG. 4 is a cross-sectional view of the vibration-damping device body constituting the fluid-filled cylindrical vibration-damping device shown in FIG. 1, and corresponds to the cross section IV-IV in FIG. 6. 5 is a cross-sectional view of the vibration isolation device main body shown in FIG. 4, which corresponds to the V-V cross section of FIG. 6. VI-VI cross-sectional view of FIG. FIG. 7 is an enlarged view of part VII in FIG. 2 . FIG. 3 is an enlarged view of part VIII in FIG. 2 . FIG. 6 is a diagram illustrating a process of attaching an outer tubular metal fitting to the integrally vulcanization molded product shown in FIG.

The following describes an embodiment of the present invention with reference to the drawings.

Figures 1 to 3 show a fluid-filled cylindrical vibration-damping device 10 according to a first embodiment of the present invention, which is suitable for use in, for example, engine mounts, motor mounts, and subframe mounts for automobiles. The fluid-filled cylindrical vibration-damping device 10 has a structure in which an outer cylindrical metal fitting 14 is fitted and fixed to the vibration-damping device main body 12, which is an integrally vulcanized molded product. The vibration-damping device main body 12 also has a structure in which an inner shaft metal fitting 16 and an intermediate sleeve 18, which serves as an intermediate cylindrical metal fitting, are connected by a main rubber elastic body 20. In the following description, in principle, the up-down direction refers to the up-down direction in Figures 1 and 3, the front-rear direction refers to the left-right direction in Figure 1, which is the central axis direction, and the left-right direction refers to the left-right direction in Figures 2 and 3.

The inner shaft fitting 16 is a thick-walled, small-diameter cylinder that extends linearly in the front-to-rear direction with a substantially constant cross section. The inner shaft fitting 16 is a highly rigid member, and is made of, for example, metal or fiber-reinforced synthetic resin.

The intermediate sleeve 18 is a thin-walled, large-diameter cylinder compared to the inner shaft fitting 16. The intermediate sleeve 18 has a first flange-shaped portion 22 integrally formed as an outer flange-shaped portion at one axial end (front end) and a second flange-shaped portion 24 integrally formed as a protruding piece at the other axial end (rear end). The first flange-shaped portion 22 protrudes toward the outer periphery at one axial end of the intermediate sleeve 18 and has a generally annular plate shape that is continuously provided around the entire circumference. The second flange-shaped portion 24 is an outer flange-shaped portion that protrudes toward the outer periphery at the axial end opposite the first flange-shaped portion 22 in the intermediate sleeve 18 and has a generally annular plate shape that is continuously provided around the entire circumference. In this embodiment, the protruding height h2 of the second flange-shaped portion 24 toward the outer periphery is greater than the protruding height h1 of the first flange-shaped portion 22 toward the outer periphery.

As shown in Figs. 1 and 3, the intermediate sleeve 18 is formed with a pair of windows 26, 26 that penetrate in the radial direction (up and down direction). The window 26 is formed in the axial center of the intermediate sleeve 18 and extends in the circumferential direction for a length that is less than halfway around. In this embodiment, the pair of windows 26, 26 have the same shape and size, but for example, the pair of windows 26, 26 may have different shapes and/or sizes.

As shown in FIG. 2, a groove-shaped portion 28, 28 extending in the circumferential direction is formed between the pair of window portions 26, 26 in the intermediate sleeve 18. The groove-shaped portion 28 extends in the circumferential direction with a concave cross section that opens on the outer circumferential surface of the intermediate sleeve 18, and both circumferential ends are connected to each of the pair of window portions 26, 26. In this embodiment, the intermediate sleeve 18 has a substantially constant thickness dimension throughout, and the axial center portion of the intermediate sleeve 18 is pressed to be concave toward the outer periphery and convex toward the inner periphery, for example, to form the groove-shaped portion 28.

The intermediate sleeve 18 is fitted onto the inner shaft fitting 16 in a state spaced apart toward the outer periphery. The inner shaft fitting 16 and the intermediate sleeve 18 are elastically connected to each other by a main rubber elastic body 20 arranged between them in the radial direction. The main rubber elastic body 20 is generally cylindrical in shape, and as shown in Figures 4 to 6, its inner circumferential surface is vulcanization bonded to the outer circumferential surface of the inner shaft fitting 16, and its outer circumferential surface is vulcanization bonded to the inner circumferential surface of the intermediate sleeve 18, forming an integral vulcanization molded product comprising the inner shaft fitting 16 and the intermediate sleeve 18.

As shown in FIG. 4, a pair of upper and lower recesses 30, 30 are formed on both sides of the main rubber elastic body 20 in the axial direction. The recesses 30 are recessed and open to the axial end face of the main rubber elastic body 20, and extend a length less than halfway around the circumference. The maximum depth of the recesses 30 is less than half the axial length of the main rubber elastic body 20.

As shown in Figures 4 and 6, the main rubber elastic body 20 has concave pockets 32, 32 that open to the outer circumferential surface on both vertical sides. The pockets 32 open to the outer periphery through the windows 26, 26 of the intermediate sleeve 18. The pockets 32 are located axially between the recesses 30, 30 on both axial sides, and the portions that form both axial walls of the pockets 32 in the main rubber elastic body 20 are thin-walled.

A stopper protrusion 34 is integrally formed with the main rubber elastic body 20. The stopper protrusion 34 is integrally formed with the inner peripheral end of the main rubber elastic body 20 fixed to the inner shaft fitting 16, and protrudes radially from the inner peripheral wall of the pocket portion 32 toward the opening. In this embodiment, a pair of stopper protrusions 34, 34 is provided on both sides in the up-down direction. The pair of stopper protrusions 34, 34 may have the same shape and size as each other, or may have different shapes and sizes as each other.

The outer peripheral surface of the intermediate sleeve 18 is covered with a coating rubber layer 36 that is integrally formed with the main rubber elastic body 20. The coating rubber layer 36 is provided continuously from the front end of the intermediate sleeve 18 to the axial middle, not reaching the second flange-shaped portion 24, and wraps around the outer periphery and front of the first flange-shaped portion 22 to be integrally connected with the main rubber elastic body 20. Therefore, the coating rubber layer 36 has a portion that protrudes outward from the first flange-shaped portion 22.

The coating rubber layer 36 has a pair of filled rubbers 38, 38 fixed in the grooved portions 28, 28 of the intermediate sleeve 18. One filled rubber 38 fills the grooved portion 28 and protrudes outward from the grooved portion 28, while the other filled rubber 38 has a support groove 40 that opens onto the outer circumferential surface, and both axially outer sides of the support groove 40 protrude outward from the grooved portion 28. The maximum outer diameter d1 of the filled rubber 38 is smaller than the outer diameter d2 of the portion of the coating rubber layer 36 that covers the outer circumferential surface of the first flange portion 22.

The coating rubber layer 36 is provided with annular seal rubbers 42, 42 on both axially outer sides of the filling rubbers 38, 38. The seal rubber 42 is continuous with a substantially constant cross-sectional shape around the entire circumference, and two seal lips 44, 44 that protrude to the outer periphery and extend in the circumferential direction are formed in parallel. The seal rubber 42 is provided at an axial position corresponding to the fitting tubular parts 62a, 62b (described later) of the outer tubular fitting 14 that is fitted and fixed to the outer periphery of the intermediate sleeve 18, and is formed to cover the fitting surface on the outer periphery of the intermediate sleeve 18 where the fitting tubular parts 62a, 62b are fitted. The outer diameter dimension d3 of the seal rubber 42 is smaller than the maximum outer diameter dimension d1 of the filling rubber 38. The outer periphery of the filling rubber 38 has tapered surfaces 46 at both axial ends that are inclined inward toward both axially outer sides, and is smoothly continuous with the outer periphery of the seal rubber 42.

A first stopper rubber 48 is fixed to the axial outer surface (front surface) of the first flange-shaped portion 22 as a stopper rubber. The first stopper rubber 48 is integrally formed with the main rubber elastic body 20 and the coating rubber layer 36. The first stopper rubber 48 has a tapered cross-sectional shape that narrows radially toward the protruding tip. The protruding height of the first stopper rubber 48 is partially reduced at multiple points in the circumferential direction, and a groove-like portion extending radially is provided, so that the protruding tip portion is divided into multiple parts in the circumferential direction. The spring constant of the first stopper rubber 48 is adjusted by the circumferential division structure of the protruding tip portion.

A second stopper rubber 50 is fixed to the axial outer surface (rear surface) of the second flange-shaped portion 24. The second stopper rubber 50 is integrally formed with the main rubber elastic body 20. The second stopper rubber 50 has a tapered cross-sectional shape that narrows radially toward the protruding tip. The protruding height of the second stopper rubber 50 is partially reduced at multiple circumferential locations, and a groove-like portion extending radially is provided, so that the protruding tip portion is divided into multiple parts circumferentially. The spring constant of the second stopper rubber 50 is adjusted by the circumferential division structure of the protruding tip portion. The second stopper rubber 50 has a larger radial width dimension than the first stopper rubber 48.

A pair of orifice members 52, 52 are attached to the vibration isolation device main body 12 constructed in this manner. As shown in Figures 1 to 3, the orifice member 52 is an approximately semi-annular body that extends a length less than halfway around the circumference, and has a groove 54 that opens onto its outer circumferential surface. One end of the groove 54 opens onto one circumferential end face of the orifice member 52, and the other end is located approximately in the center of the circumference and opens onto the axial end face of the orifice member 52.

The pair of orifice members 52, 52 are arranged so as to straddle the opening of one of the pocket portions 32 in the circumferential direction, and are fitted into the grooved portions 28, 28 of the intermediate sleeve 18, both circumferential ends of which are covered with the rubber coating layer 36. In this embodiment, the pair of orifice members 52, 52 are common parts, and are assembled in an inverted upside-down orientation, so that the grooves 54, 54 of the pair of orifice members 52, 52 are connected so as to extend continuously in the circumferential direction over approximately half the circumference. The circumferential groove formed by the interconnected grooves 54, 54 opens into one of the pocket portions 32, 32 at its end.

The outer tubular metal fitting 14 is attached to the vibration isolation device main body 12 to which the orifice members 52, 52 are assembled. The outer tubular metal fitting 14 is made of a metal such as iron, and as shown in Figs. 1 to 3, has a thin-walled, large-diameter cylindrical shape overall. In this embodiment, the outer tubular metal fitting 14 is a single metal fitting with no rubber elastic body attached. The outer tubular metal fitting 14 is integrally provided with an outer flange-shaped outer flange portion 58 that protrudes to the outer periphery at the rear end of the cylindrical portion 56. The cylindrical portion 56 of the outer tubular metal fitting 14 has an axial middle portion that is a large-diameter mounting cylindrical portion 60, and both axial end portions (front end portion and rear end portion) are fitting cylindrical portions 62a, 62b that are smaller in diameter than the mounting cylindrical portion 60. The mounting cylindrical portion 60 and the fitting cylindrical portions 62a, 62b are integrally continuous with each other through tapered portions 64, 64 that become smaller in diameter toward the axial outward direction. The mounting tubular portion 60 has a tubular outer peripheral surface 66 with a substantially constant diameter dimension in the axial direction. The front end of the cylindrical portion 56 of the outer tubular fitting 14 is provided with an inward protrusion 67 that is bent inward and protrudes. In this embodiment, one fitting tubular portion 62a is provided at the front end portion of the outer tubular fitting 14, and the other fitting tubular portion 62b is provided at the rear end portion of the outer tubular fitting 14.

As shown in Figures 7 and 8, the fitting tubular parts 62a, 62b of the outer tubular fitting 14 are fitted and fixed to the intermediate sleeve 18 via the seal rubbers 42, 42 of the coating rubber layer 36. The seal rubbers 42, 42 of the coating rubber layer 36 are compressed radially between the fitting tubular parts 62a, 62b of the outer tubular fitting 14 and the intermediate sleeve 18, so that the fitting surfaces of the fitting tubular parts 62a, 62b of the outer tubular fitting 14 and the intermediate sleeve 18 are liquid-tightly sealed. This prevents leakage of the non-compressible fluid (liquid) sealed in the fluid chambers 68, 68 and the orifice passage 70 described below.

The outer flange portion 58 of the outer tubular fitting 14 is overlapped in the axial direction on the second flange-shaped portion 24 of the intermediate sleeve 18. This positions the outer tubular fitting 14 in the axial direction relative to the intermediate sleeve 18. In this embodiment, the second flange-shaped portion 24 and the outer flange portion 58 are overlapped in a state of direct contact without the intervention of rubber, making it possible to position the outer tubular fitting 14 and the intermediate sleeve 18 with high precision in the axial direction.

The second flange-like portion 24, which is superimposed on the axial outer surface (rear surface) of the outer flange portion 58, abuts against a second stopper receiving portion (not shown) arranged axially outwardly and facing the first stopper rubber 50, thereby forming a second axial stopper that limits the amount of relative axial displacement between the inner shaft fitting 16 and the outer tubular fitting 14.

The front end of the intermediate sleeve 18 on which the first flange-shaped portion 22 is provided protrudes forward from the outer tubular fitting 14. The first flange-shaped portion 22 protrudes toward the outer periphery forward from the outer tubular fitting 14, and overlaps with the fitting tubular portions 62a, 62b when projected in the axial direction. The first flange-shaped portion 22 exposed forward from the outer tubular fitting 14 abuts against a first stopper receiving portion (not shown) arranged oppositely in the axial direction outward via the first stopper rubber 48, thereby forming a first axial stopper that limits the amount of relative axial displacement between the inner shaft fitting 16 and the outer tubular fitting 14.

The window portions 26, 26 of the intermediate sleeve 18 are covered by the mounting tubular portion 60 and tapered portions 64, 64 of the outer tubular metal fitting 14. As a result, the openings of the pocket portions 32, 32 are covered by the outer tubular metal fitting 14, forming a pair of fluid chambers 68, 68 isolated from the outside. The fluid chamber 68 is filled with a non-compressible fluid such as water or ethylene glycol, and more preferably a low-viscosity liquid. At least a portion of the wall of the fluid chamber 68 is formed by the main rubber elastic body 20, and the fluid chamber 68 is a pressure-receiving chamber in which internal pressure fluctuations are induced by deformation of the main rubber elastic body 20.

The mounting tubular portion 60 of the outer tubular metal fitting 14 is superimposed on the outer peripheral surface of the orifice member 52, 52. As a result, the outer peripheral opening of the groove 54, 54 is covered by the outer tubular metal fitting 14, forming an orifice passage 70 extending in the circumferential direction. The orifice passage 70 has both ends opening into one of the fluid chambers 68, 68, and these fluid chambers 68, 68 are in communication with each other. The resonant frequency of the liquid flowing through the orifice passage 70 is set to the frequency of the vibration to be damped by the ratio of the passage cross-sectional area to the passage length. In addition, on both axial outsides of the orifice member 52, 52, the filling rubber 38, 38 is pressed against the tapered portion 64, 64 of the outer tubular metal fitting 14, and both axial outsides of the orifice member 52, 52 are liquid-tightly sealed.

When the fluid-filled cylindrical vibration-damping device 10 constructed in this manner is mounted on a collar member 72 (described later) as an additional member and installed in a vehicle, it exerts a vibration-damping effect based on the flow action of the liquid flowing between the fluid chambers 68, 68 through the orifice passage 70 against vertical vibrations input between the inner shaft fitting 16 and the outer cylindrical fitting 14. The inner shaft fitting 16 is fixed, for example, to the vehicle body (not shown).

As shown in FIG. 9, the outer tubular metal fitting 14 is formed as an outer tubular metal fitting 14' in which the cylindrical portion 56 has a substantially constant diameter dimension over the entire axial length, and when the outer tubular metal fitting 14' is fitted and fixed to the vibration-proof device main body 12, both axial end portions of the outer tubular metal fitting 14' are reduced in diameter to form the mounting tubular portion 60, the tapered portions 64, 64, and the fitting tubular portions 62a, 62b.

9, the outer tubular fitting 14' before the diameter reduction process has a minimum inner diameter dimension D1 that is larger than the outer diameter dimension d4 of the first flange-shaped portion 22 of the intermediate sleeve 18. The outer tubular fitting 14' is then axially inserted from the first flange-shaped portion 22 side (front side) onto the intermediate sleeve 18, so that the front end portion of the intermediate sleeve 18 on which the first flange-shaped portion 22 is provided protrudes forward from the outer tubular fitting 14'. The outer tubular fitting 14' inserted onto the intermediate sleeve 18 in this manner is subjected to diameter reduction process to form the outer tubular fitting 14 having the mounting tubular portion 60, the tapered portions 64, 64, and the fitting tubular portions 62a, 62b, and the outer tubular fitting 14 is fitted and fixed to the intermediate sleeve 18. In the process of fitting the outer tubular fitting 14' to the intermediate sleeve 18 by reducing the diameter, the outer tubular fitting 14' may be entirely reduced in diameter so that the amount of deformation due to reduction is particularly large in the areas where the fitting tubular parts 62a and 62b are formed, or only the areas where the fitting tubular parts 62a and 62b are formed may be reduced in diameter.

In this embodiment, the outer diameter d2 of the coating rubber layer 36 that covers the outer periphery of the first flange-shaped portion 22 is made larger than the inner diameter D2 of the outer tubular metal fitting 14', and when the outer tubular metal fitting 14' is inserted into the vibration isolation device main body 12, the inner peripheral surface of the outer tubular metal fitting 14' is guided by sliding contact with the coating rubber layer 36, improving workability.

As shown in Figures 2 and 7, the inner diameter D3 of the fitting tubular portions 62a, 62b of the outer tubular fitting 14 after diameter reduction is smaller than the outer diameter d4 of the first flange portion 22 of the intermediate sleeve 18, preventing the outer tubular fitting 14 from coming loose in the axial direction from the intermediate sleeve 18.

On the other hand, the outer diameter dimension D4 of the mounting tubular portion 60 of the outer tubular fitting 14 after the diameter reduction process is made larger than the outer diameter dimension d4 of the first flange-shaped portion 22 of the intermediate sleeve 18, and the cylindrical outer peripheral surface 66 of the mounting tubular portion 60 protrudes outward from the first flange-shaped portion 22 when projected in the axial direction. The mounting tubular portion 60 may be located on the inner peripheral side of the coating rubber layer 36 that covers the outer peripheral surface of the first flange-shaped portion 22, or may protrude outward.

The fluid-filled cylindrical vibration-damping device 10 is then, as shown in Figs. 1 and 2, pressed into an assembly hole 74 of a cylindrical collar member 72 provided on a subframe, for example. That is, the outer cylindrical metal fitting 14 is fixed to the collar member 72 by pressing the mounting cylindrical portion 60 of the outer cylindrical metal fitting 14 into the inner peripheral surface of the collar member 72. Since the mounting cylindrical portion 60 of the outer cylindrical metal fitting 14 protrudes outward from the first flange portion 22 of the intermediate sleeve 18, the mounting cylindrical portion 60 can be pressed into the collar member 72 while allowing the first flange portion 22 to pass through the assembly hole 74 of the collar member 72. In this way, the fluid-filled cylindrical vibration-damping device 10 can be easily fixed to the collar member 72 by pressing the outer cylindrical metal fitting 14 into the collar member 72 while forming an axial stopper using the first flange portion 22 by forming the first flange portion 22 on the intermediate sleeve 18.

The outer peripheral surface of the first flange-shaped portion 22 is covered by a coating rubber layer 36 fixed to the outer peripheral surface of the intermediate sleeve 18, and the radial space between the first flange-shaped portion 22 and the collar member 72 is sealed by the coating rubber layer 36 arranged in a compressed state. This makes it possible to prevent foreign matter such as rainwater and dust from entering between the fluid-filled cylindrical vibration-damping device 10 and the collar member 72.

The first flange-shaped portion 22 of the intermediate sleeve 18 constitutes a stopper on one side of the axial direction, and the first stopper rubber 48 is fixed to the first flange-shaped portion 22, so that the first stopper rubber 48 can be integrally formed with the main rubber elastic body 20, and there is no need to form a stopper rubber on the outer tubular metal fitting 14. In this embodiment, the other axial stopper is constituted by the second flange-shaped portion 24, and the second stopper rubber 50 is integrally formed with the main rubber elastic body 20 and fixed to the second flange-shaped portion 24, so that the outer tubular metal fitting 14 is a single metal fitting to which no rubber is fixed. Therefore, the rubber vulcanization molding process is not required except for the vibration-proof device main body 12, and the fluid-filled cylindrical vibration-proof device 10 can be easily manufactured. In this embodiment, the main rubber elastic body 20, the coating rubber layer 36, and the first and second stopper rubbers 48, 50 are all integral, and these rubbers can be vulcanized and molded at the same time.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the specific description. For example, the coating rubber layer 36 fixed to the inner peripheral surface of the intermediate sleeve 18 is desirably formed integrally with the main rubber elastic body 20 provided on the inner peripheral side of the intermediate sleeve 18, but may be formed independently of the main rubber elastic body 20. Also, the first and second stopper rubbers 48, 50 may be formed independently of the main rubber elastic body 20. Note that the coating rubber layer 36 and the first and second stopper rubbers 48, 50 are not essential.

In the above embodiment, the seal rubber 42, 42 interposed between the intermediate sleeve 18 and the fitting tubular portions 62a, 62b of the outer tubular metal fitting 14 was fixed to the outer peripheral surface of the intermediate sleeve 18, but the seal rubber 42, 42 may be fixed to the inner peripheral surface of the fitting tubular portions 62a, 62b of the outer tubular metal fitting 14. Note that while it is preferable that the outer tubular metal fitting 14 is a single metal fitting, it may be a vulcanization molded product with rubber fixed thereto.

The second flange portion 24 of the intermediate sleeve 18 is not essential. In addition, if the second flange portion 24 is omitted, for example, a stopper rubber can be formed on the axial outer surface (rear surface) of the outer flange portion 58 of the outer tubular metal fitting 14, and the axial stopper can be formed by the outer flange portion 58.

The fitting tubular portion of the outer tubular fitting 14 does not necessarily have to be provided on both axially outer sides of the mounting tubular portion 60. Only the fitting tubular portion 62a on the first flange portion 22 side (front side) may be provided, and the fitting tubular portion 62b on the second flange portion 24 side (rear side) may be omitted. Also, instead of the fitting tubular portion 62b, a press-fit tubular portion with the same diameter as the mounting tubular portion 60 may be used, or the second flange portion 24 side may be sealed with a separate seal member.

The collar member 72 does not have to reach the outer periphery of the first flange-shaped portion 22, and the gap between the collar member 72 and the first flange-shaped portion 22 does not have to be sealed by the coating rubber layer 36 that covers the first flange-shaped portion 22.

In the above embodiment, an example was shown in which a pair of fluid chambers 68, 68 having the same structure were formed, but the pair of fluid chambers may have different structures, for example, one being a pressure-receiving chamber and the other being an equilibrium chamber. The number of fluid chambers is not limited to two, and may be three or more.

The orifice member that forms the orifice passage 70 may be, for example, a single C-shaped annular part. It is also possible to form the orifice passage by the groove portion 28 of the intermediate sleeve 18 and the filling rubber 38 fixed to the groove portion 28 without providing an orifice member. However, the specific structure of the orifice passage is not limited in the present invention, and for example, the orifice passage may be formed on the inner shaft member side, or it may be formed by penetrating the main rubber elastic body, and an orifice passage that does not require a special orifice member may be adopted.

10 Fluid-filled cylindrical vibration-damping device (first embodiment)
12 Anti-vibration device body (integral vulcanization molded product)
14 Outer tubular metal fitting 14' Outer tubular metal fitting 16 Inner shaft metal fitting 18 Intermediate sleeve (intermediate tubular metal fitting)
20 Main rubber elastic body 22 First flange-shaped portion (outer flange-shaped portion)
24 Second flange-like portion (projecting piece)
26 Window portion 28 Groove-shaped portion 30 Hollow recess 32 Pocket portion 34 Stopper protrusion 36 Covering rubber layer 38 Filling rubber 40 Support groove 42 Seal rubber 44 Seal lip 46 Tapered surface 48 First stopper rubber (stopper rubber)
50: second stopper rubber 52: orifice member 54: groove 56: cylindrical portion 58: outer flange portion 60: mounting tubular portion 62a: fitting tubular portion 62b: fitting tubular portion (the other fitting tubular portion)
64 Tapered portion 66 Cylindrical outer peripheral surface 67 Inward protrusion 68 Fluid chamber 70 Orifice passage 72 Collar member (other member)
74 Assembly hole

Claims (9)

a fluid-filled cylindrical vibration-damping device in which an outer tubular metal fitting is fitted and fixed to an integrally vulcanization-molded product in which an inner shaft fitting and an intermediate tubular metal fitting are elastically connected by a main rubber elastic body, and a pocket portion opening onto an outer circumferential surface of the integrally vulcanization-molded product is covered by the outer tubular metal fitting to form a fluid chamber,
An outer flange-shaped portion that projects in the axial direction from the outer tubular member and spreads outwardly toward the outer periphery is integrally formed at an axial end of the intermediate tubular member,
the outer tubular fitting has, at an axially intermediate portion, a tubular portion for attachment to another member, the tubular portion having a tubular outer peripheral surface with a diameter larger than an outer diameter of the outer flange portion of the intermediate tubular fitting,
The outer tubular fitting is a fluid-filled cylindrical vibration-damping device that has a fitting tubular portion at the axial end of the intermediate tubular fitting on the outer flange-shaped portion side, the fitting tubular portion having a smaller diameter than the outer diameter of the outer flange-shaped portion and is fixed to the outside of the intermediate tubular fitting. The fluid-filled cylindrical vibration-damping device according to claim 1, wherein the outer cylindrical metal fitting is a single metal fitting with no rubber elastic body attached. The fluid-filled cylindrical vibration-proof device according to claim 1 or 2, in which the outer tubular metal fitting has an outer flange-shaped outer flange portion that extends outwardly and is integrally formed at the axial end of the intermediate tubular metal fitting opposite the outer flange-shaped portion. the intermediate tubular fitting is provided with an outer flange-shaped protruding piece that spreads outwardly at an axial end portion opposite the outer flange-shaped portion,
4. A fluid-filled cylindrical vibration-damping device according to claim 3, wherein said protruding piece overlaps with said outer flange portion of said outer tubular metal fitting in the axial direction. The fluid-filled cylindrical vibration-proof device according to claim 1 or 2, wherein the outer tubular metal fitting has, at the axial end opposite the outer flange portion of the intermediate tubular metal fitting, another fitted tubular portion having a smaller diameter than the outer diameter of the outer flange portion and fixed to the intermediate tubular metal fitting. A fluid-filled cylindrical vibration-proof device according to claim 1 or 2, in which a stopper rubber is fixed to the axial outer surface of the outer flange-shaped portion of the intermediate cylindrical fitting. A fluid-filled cylindrical vibration-damping device according to claim 1 or 2, in which a coating rubber layer is fixed to the outer peripheral surface of the intermediate cylindrical metal fitting, and the portion of the coating rubber layer that covers the outer flange-shaped portion protrudes outward from the outer flange-shaped portion. The fluid-filled cylindrical vibration-proof device according to claim 1 or 2, wherein the fitting surface of the fitting tubular portion of the outer cylindrical metal fitting of the intermediate cylindrical metal fitting is covered with a sealing rubber. In manufacturing a fluid-filled cylindrical vibration-damping device in which an outer tubular metal fitting is fitted and fixed to an integrally vulcanization-molded product in which an inner shaft fitting and an intermediate tubular metal fitting are elastically connected by a main rubber elastic body, and a pocket portion opening onto the outer circumferential surface of the integrally vulcanization-molded product is covered by the outer tubular metal fitting to form a fluid chamber,
the intermediate tubular member is provided with an outer flange-shaped portion that projects axially from the outer tubular member at an axial end portion thereof and that extends radially outward;
the outer tubular metal fitting having an inner diameter dimension larger than an outer diameter dimension of the outer flange-like portion is fitted onto the intermediate tubular metal fitting of the integrally vulcanization molded product from the outer flange-like portion side;
A method for manufacturing a fluid-filled cylindrical vibration-damping device comprising the steps of: applying diameter reduction processing to the outer tubular fitting to form a tubular portion for attachment to another member in an axially middle portion of the outer tubular fitting, the tubular portion having a tubular outer peripheral surface with a diameter larger than the outer diameter of the outer flange-like portion of the intermediate tubular fitting; and forming fitting tubular portions on both axial sides of the mounting tubular portion of the outer tubular fitting, the fitting tubular portions having a diameter smaller than the outer diameter of the outer flange-like portion of the intermediate tubular fitting and being externally fitted and fixed to the intermediate tubular fitting.

Images