JP6722570B2 - Fluid-filled cylindrical anti-vibration device - Google Patents

Description

The present invention relates to a fluid-filled tubular vibration damping device used in a suspension bush of an automobile.

BACKGROUND ART Conventionally, as a kind of a vibration-proof coupling body or a vibration-proof support body that is interposed between members constituting a vibration transmission system and mutually couples the components of the vibration transmission system with each other in a vibration-proof manner, a cylindrical vibration-damping device is provided. It has been known. This cylindrical vibration isolator has a structure in which an inner shaft member and an outer cylinder member are elastically connected to each other by a rubber elastic body, and the inner shaft member and the outer cylinder member are each one of the constituent members of the vibration transmission system. It can be attached to. Further, as one type of the cylindrical vibration damping device, as shown in Japanese Patent No. 5026999 (Patent Document 1), a fluid-filled cylinder that utilizes the flow action of an incompressible fluid sealed inside. Shape-damping devices have also been proposed. This fluid-filled tubular vibration damping device has a pair of fluid chambers in which an incompressible fluid is filled, and an orifice passage that connects the pair of fluid chambers to each other. At the time of vibration input, the relative pressure fluctuation of the pair of fluid chambers causes the fluid flow through the orifice passage, and the vibration damping effect based on the fluid flow action is exhibited.

By the way, the fluid-filled tubular vibration-damping device described in Patent Document 1 is provided with a fixing metal fitting which is superposed on the inner peripheral surface of the orifice half forming the orifice passage, and between the orifice half and the fixing metal fitting. A movable member is disposed in the. In Patent Document 1, for example, the fixing fitting is press-fitted into the press-fitting recess of the orifice half body, so that the orifice half body and the fixing fitting are connected with the movable member accommodated therebetween.

However, if the fixing metal fitting is simply press-fitted to the orifice half body, and if the fixing metal fitting comes out of the orifice half body, the fixing metal fitting is immediately separated from the orifice half body, and the protection that should be realized by the movable member should be realized. It was also considered that the vibration performance could not be obtained.

Japanese Patent No. 5026999

The present invention has been made in view of the above circumstances, and a problem to be solved is to more effectively prevent separation of an orifice member and an inner peripheral lid member and realize excellent reliability. (EN) Provided is a fluid-filled tubular vibration damping device having a novel structure that can be used.

Hereinafter, embodiments of the present invention made to solve such problems will be described. The constituent elements used in each of the following aspects can be used in any combination as much as possible.

That is, according to the first aspect of the present invention, the inner shaft member and the outer tubular member are elastically connected to each other by the main rubber elastic body to form a fluid chamber in which an incompressible fluid is sealed, and In the fluid filled cylindrical vibration damping device, an orifice member is provided which extends in an inner circumference of the outer tubular member in a circumferential direction, and an orifice passage formed in the orifice member is connected to the fluid chamber. An inner peripheral cover member is provided so as to be superposed on the inner peripheral surface of the member, and a storage region in which an incompressible fluid is sealed is formed between the orifice member and the inner peripheral cover member. The accommodation area is partitioned by the movable member disposed in the area into the orifice member side and the inner peripheral lid member side, and the orifice member side of the accommodation area communicates with the orifice passage and the accommodation area. The inner peripheral lid member side is communicated with the fluid chamber through a communication hole penetrating the inner peripheral lid member, while the main body rubber elastic body is in contact with the inner peripheral surface of the inner peripheral lid member to cause the orifice. The member and the inner peripheral lid member are positioned in the stacking direction.

According to the fluid filled tubular vibration damping device having the structure according to the first aspect, the orifice member and the inner peripheral lid member are arranged at predetermined positions with respect to the main rubber elastic body and the outer tubular member. The positioning of the orifice member and the inner peripheral lid member in the overlapping direction is easily realized by the contact of the main rubber elastic body with the inner peripheral lid member. As a result, the orifice member and the inner peripheral lid member are easily prevented from being separated from each other, and the desired vibration damping performance can be stably obtained with excellent reliability.

A second aspect of the present invention is the fluid-filled tubular vibration damping device according to the first aspect, wherein the orifice member is formed with a protrusion protruding toward the inner peripheral side, and A hole corresponding to the protrusion is formed in the lid member, and the protrusion is inserted into the hole to position the orifice member and the inner peripheral lid member relative to each other. ..

According to the second aspect, by inserting the protrusion into the hole, at least in the direction perpendicular to the axis of the protrusion, the outer peripheral surface of the protrusion abuts the inner wall surface of the hole, and the orifice member and the inner periphery are contacted. The relative displacement amount of the lid member is limited, and the orifice member and the inner peripheral lid member are positioned relative to each other. Therefore, in addition to the positioning of the main rubber elastic body by the contact with the inner peripheral lid member, the positioning by inserting the projection into the hole portion further stabilizes the orifice member and the inner peripheral lid member at a predetermined relative position. Can be held.

A third aspect of the present invention is the fluid-filled tubular vibration damping device according to the second aspect, wherein the projecting tip of the protrusion of the orifice member inserted into the hole of the inner peripheral lid member. The orifice member and the inner peripheral lid member are connected by locking the portion to the inner peripheral lid member by caulking.

According to the third aspect, the protruding tip end of the protrusion inserted into the hole is crushed, and the protruding tip end of the enlarged diameter protrusion is locked to the opening peripheral edge of the hole in the inner peripheral lid member. As a result, the orifice member and the inner peripheral lid member are more firmly connected. In addition, even if the connection between the orifice member and the inner peripheral lid member is released by caulking the projection portion due to damage to the projection portion, the orifice member and the inner peripheral lid member are the inner peripheral lid member of the main rubber elastic body. Is held in a relatively positioned state by abutting against.

A fourth aspect of the present invention is the fluid-filled tubular vibration damping device according to the second or third aspect, wherein the holes are formed at both ends in the circumferential direction of the inner peripheral lid member. The main rubber elastic body is in contact with the inner peripheral surfaces of both end portions in the circumferential direction of the inner peripheral lid member.

According to the fourth aspect, the positioning structure by abutting the main rubber elastic body on the inner peripheral lid member and the positioning structure by inserting the protrusion into the hole are both end portions in the circumferential direction of the inner peripheral lid member. With this configuration, it is possible to form a hole or the like for transmitting the hydraulic pressure of the fluid chamber to the movable member in the central portion in the circumferential direction of the inner peripheral lid member. Further, since the orifice member and the inner peripheral lid member are positioned at positions separated from each other in the circumferential direction, the orifice member and the inner peripheral lid member are more stably held in the positioned state.

A fifth aspect of the present invention is the fluid filled tubular vibration damping device according to any one of the first to fourth aspects, wherein the contact surface of the main rubber elastic body in the inner peripheral lid member is The plane is a plane that extends orthogonal to the direction in which the orifice member and the inner peripheral lid member are overlapped.

According to the fifth aspect, the contact direction of the main body rubber elastic body with respect to the inner peripheral cover member is substantially orthogonal to the contact surface of the main body rubber elastic body in the inner peripheral cover member. It is possible to efficiently obtain the positioning action by the contact of the rubber elastic body with the inner peripheral lid member.

According to the present invention, since the main body rubber elastic body is brought into contact with the inner peripheral surface of the inner peripheral cover member, the orifice member and the inner peripheral cover member are positioned in the overlapping direction. Is located at a predetermined position with respect to the main body rubber elastic body and the outer tubular member, the positioning of the orifice member and the inner peripheral lid member in the stacking direction can be easily realized, and the desired vibration damping performance is excellent. It can be obtained reliably and stably.

It is sectional drawing which shows the suspension bush as 1st embodiment of this invention, Comprising: It is a figure corresponded to the II cross section of FIG. II-II sectional drawing of FIG. The top view which shows the integrally vulcanization molded article of the main body rubber elastic body which comprises the suspension bush of FIG. FIG. 4 is a right side view of the integrally vulcanized molded product shown in FIG. 3. FIG. 4 is a left side view of the integrally vulcanized molded product shown in FIG. 3. The top view which shows the orifice assembly which comprises the suspension bush of FIG. FIG. 7 is a bottom view of the orifice assembly shown in FIG. 6. VIII-VIII sectional drawing of FIG. IX-IX sectional drawing of FIG. The perspective view which decomposes|disassembles and shows the orifice assembly shown in FIG. FIG. 7 is a bottom view of a movable member forming the orifice assembly of FIG. 6. XII-XII sectional drawing of FIG. Sectional drawing which shows the state in which the up-down large load was input into the suspension bush of FIG.

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

1 and 2 show a suspension bush 10 for an automobile as a first embodiment of a fluid filled tubular vibration damping device having a structure according to the present invention. The suspension bush 10 has a structure in which an inner shaft member 12 and an outer cylinder member 14 are elastically connected by a main rubber elastic body 16. In the suspension bush 10, for example, the inner shaft member 12 is attached to a vehicle body (not shown), and the outer cylinder member 14 is attached to a suspension arm (not shown) that is a member on the wheel side. The vehicle body and the suspension arm are interposed between the vehicle body and the suspension arm for vibration-proof connection with each other. In the following description, in principle, the up-down direction refers to the up-down direction in FIG. 1, and the left-right direction refers to the left-right direction in FIG.

More specifically, the inner shaft member 12 is a high-rigidity member formed of metal or the like, has a rod shape extending in a substantially constant cross-sectional shape, and has a circular cross-section through which a bolt is inserted. The hole 18 is formed so as to penetrate therethrough in the axial direction. Further, a stopper member 20 is attached to a central portion of the inner shaft member 12 in the axial direction. The stopper member 20 is made of synthetic resin or the like and is fixed to the outer peripheral surface of the inner shaft member 12, and has a substantially rectangular cross-sectional shape in the present embodiment, and extends from the inner shaft member 12 to the outer peripheral side. The protrusion size of is larger in the horizontal direction than in the vertical direction. In the stopper member 20 of the present embodiment, the upper and lower outer surfaces are substantially flat surfaces, and the left and right outer surfaces are curved surfaces that are curved in the circumferential direction and the axial direction. The shape of the inner shaft member 12 is not particularly limited, and may be, for example, a cylindrical shape.

An intermediate cylinder member 22 is arranged on the outer peripheral side of the inner shaft member 12. The intermediate tubular member 22 is a high-rigidity member made of metal or the like, and has a thin-walled and large-diameter substantially cylindrical shape as compared with the inner shaft member 12. Further, as shown in FIGS. 1 to 5, a pair of windows 24, 24 are formed in the axially intermediate portion of the intermediate tubular member 22. The window portion 24 penetrates the intermediate tubular member 22 in the radial direction, has a length of a little less than half the circumference of the intermediate tubular member 22 in the circumferential direction, and is provided on both sides in one radial direction. Furthermore, as shown in FIGS. 4 and 5, a pair of groove portions 26, 26 are formed between the pair of window portions 24, 24 in the intermediate tubular member 22 in the circumferential direction. The groove-like portion 26 extends in the circumferential direction at an intermediate portion in the axial direction (left-right direction in FIG. 4) of the intermediate tubular member 22 with a groove width dimension smaller than that of the window portion 24, and has a pair of circumferential end portions. It is connected to each one of the windows 24, 24.

Such an intermediate cylinder member 22 is externally inserted to the inner shaft member 12 on substantially the same central axis, and the main rubber elastic body 16 is disposed between the inner shaft member 12 and the intermediate cylinder member 22. There is. The main rubber elastic body 16 has a thick-walled, substantially cylindrical shape, and has an inner peripheral surface fixed to the outer peripheral surface of the inner shaft member 12 and an outer peripheral surface fixed to the inner peripheral surface of the intermediate cylindrical member 22. The inner shaft member 12 and the intermediate tubular member 22 are elastically connected by the main rubber elastic body 16. In this embodiment, the main rubber elastic body 16 is formed as an integral vulcanization molded product 28 including the inner shaft member 12 and the intermediate tubular member 22. Further, after the main rubber elastic body 16 is vulcanized and molded, the intermediate cylindrical member 22 is subjected to a diameter reduction process such as an eight-sided drawing to reduce the tensile stress due to the cooling contraction of the main rubber elastic body 16 and the durability. It is desirable to improve the property.

Further, the inner surfaces of the grooves of the pair of groove-shaped portions 26, 26 of the intermediate tubular member 22 are covered with a thin rubber layer integrally formed with the main rubber elastic body 16, and are axially provided at two locations in the circumferential direction. An extending seal lip 30 is formed integrally with the rubber layer. Further, as shown in FIG. 4, the rubber layer covering one of the groove portions 26 is integrally formed with an abutting protrusion 32 that protrudes in the radial direction at the central portion in the circumferential direction and the axial direction.

Furthermore, the main rubber elastic body 16 is formed with a pair of pocket portions 34, 34. The pocket portion 34 has a recessed shape that opens to the outer peripheral surface at the axially intermediate portion of the main rubber elastic body 16, and is formed on both radial sides of the inner shaft member 12. Further, a stopper rubber 36 projecting to the outer peripheral side is integrally formed with the main rubber elastic body 16 on the inner peripheral bottom surface of the pocket portion 34. In the present embodiment, the stopper rubber 36 is provided with three mountain-shaped protrusions arranged in the left-right direction in FIG. 1, and the center of the left and right sides has a larger protruding dimension than the left and right sides. Further, on the protruding tip end surface of the stopper rubber 36, concave grooves and ridges continuous in the circumferential direction are alternately provided in the axial direction, and the contact of the stopper rubber 36 described later with the inner peripheral lid member 62 is buffered. Are being realized.

Further, the pocket portion 34 has an opening shape corresponding to the window portion 24 of the intermediate tubular member 22, and the opening portion of the pocket portion 34 is aligned with the window portion 24, so that the pocket in the main rubber elastic body 16 is formed. The opening peripheral edge portion of the portion 34 is fixed to the opening edge portion of the window portion 24, and the pocket portion 34 is opened to the outer peripheral side through the window portion 24. In particular, contact portions 38 integrally formed with the main rubber elastic body 16 are fixed to the opening edge portions on both sides in the circumferential direction of the window portion 24, and the contact portions 38 are disposed on both sides in the axial direction of the window portion 24. It is thicker than the rubber elastic body fixed to the opening edge. Further, the abutting portion 38 is provided in the axially central portion of the window portion 24, and the axially opposite side portions of the abutting portion 38 in the main rubber elastic body 16 are made thinner than the abutting portion 38. Recessed recesses 39 are formed on both axial sides of the contact portion 38.

Further, as shown in FIGS. 1 and 2, the outer tubular member 14 is attached to the integrally vulcanized molded product 28 of the main rubber elastic body 16. The outer tubular member 14 is a high-rigidity member made of metal or the like, has a thin, large-diameter, generally cylindrical shape, and has an inner peripheral surface covered with a seal rubber layer 40. The outer tubular member 14 is reduced in diameter in a state where it is externally inserted into the integrally vulcanized molded product 28 of the main rubber elastic body 16, so that the outer tubular member 14 is processed with respect to the intermediate tubular member 22 constituting the integrally vulcanized molded product 28. It is installed by external fitting. The outer tubular member 14 is fitted to the intermediate tubular member 22 at a portion outside the pair of window portions 24, 24 and the pair of groove portions 26, 26 of the intermediate tubular member 22. Further, the seal rubber layer 40 is interposed in a compressed state between the fitting portions of the intermediate tubular member 22 and the outer tubular member 14, and the fitting surfaces of the intermediate tubular member 22 and the outer tubular member 14 are fluid-tightly sealed. Has been done.

A pair of orifice assemblies 42, 42 are arranged between the intermediate cylinder member 22 and the outer cylinder member 14. As shown in FIGS. 6 to 10, the orifice assembly 42 is a substantially semi-cylindrical member that extends in the circumferential direction along the inner peripheral surface of the outer tubular member 14, and is arranged so as to face each other in the radial direction. It has a pair of orifice members 44, 44.

The orifice member 44 is a hard mold product formed of metal, synthetic resin, or the like, and has a substantially semi-cylindrical shape as a whole, and the outer peripheral surface is a semi-cylindrical surface along the inner peripheral surface of the outer tubular member 14. It is a curved surface. Further, in the orifice member 44, the central portion in the circumferential direction is made thicker than both end portions, and in the thick central portion, a first recess 46 opening to the inner peripheral surface of the orifice member 44, A second recess 48 that opens to the bottom surface of the first recess 46 is formed. Furthermore, a stepped surface 50 as a flat surface is formed at the boundary between the thick central portion and the thin end portions on the inner peripheral surface of the orifice member 44. The step surface 50 is a flat surface that extends substantially orthogonal to the radial direction (the vertical direction in FIG. 8) in which the pair of orifice members 44, 44 oppose each other, and the diameter in which the pair of orifice members 44, 44 oppose each other. A protrusion 52 that protrudes toward the inner peripheral side in the direction is formed integrally with the orifice member 44 so as to protrude at the step surface 50. The circumferential end portions of the orifice member 44 are smaller in axial dimension than the circumferential central portion.

Further, the orifice member 44 is formed with a first circumferential groove 54 and a second circumferential groove 56 that open in the outer peripheral surface and extend in the circumferential direction. The first circumferential groove 54 is formed continuously over the entire length of the orifice member 44 in the circumferential direction, opens at both circumferential end surfaces of the orifice member 44, and has a central portion in the circumferential direction of the orifice member 44. An intermediate communication hole 58 as a communication hole penetrating in the radial direction is formed, and the intermediate communication hole 58 is connected to the second recess 48. On the other hand, the second circumferential groove 56 is formed at one end portion in the circumferential direction of the orifice member 44 with a length shorter than the half circumference in the circumferential direction of the orifice member 44, and one end portion in the circumferential direction of the orifice member 44. While opening on the end face, the other end is communicated with the inner peripheral side of the orifice member 44 through an end communication hole 60 penetrating the orifice member 44. The central portion of the first circumferential groove 54 in the circumferential direction is inclined in the axial direction and extends in the circumferential direction, and one end portion of the first circumferential groove 54 in the circumferential direction is located in the central portion of the orifice member 44 in the axial direction. On the other hand, the second circumferential grooves 56 are arranged side by side in the axial direction with respect to the circumferential end portions of the first circumferential grooves 54 that are biased outward in the axial direction and are biased in the axial direction. It is arranged.

An inner peripheral lid member 62 is superposed on the inner peripheral surface of the orifice member 44. The inner peripheral lid member 62 is a plate-shaped member formed of metal or the like, and has a flat plate shape at both ends in the circumferential direction, and the contact portion 38 of the main rubber elastic body 16 is pressed against the inner peripheral cover member 62. The contact flat surface 63 as a contact surface is provided on the inner peripheral side, and the center portion in the circumferential direction is a curved plate shape convex toward the outer peripheral side. The inner peripheral cover member 62 of the present embodiment is provided with a notch 64 at one end portion in the circumferential direction, and one end portion in the circumferential direction has a smaller axial dimension than the other end portion.

Further, in the central portion of the inner peripheral lid member 62 in the circumferential direction, two through holes 66, 66 penetrating in the thickness direction are formed apart from each other in the circumferential direction. Furthermore, holes 68 penetrating in the thickness direction are formed at both ends in the circumferential direction of the inner peripheral lid member 62 in a sectional shape corresponding to the protrusions 52 of the orifice member 44. In the present embodiment, in the inner peripheral lid member 62, one hole 68 is formed at one end in the circumferential direction in which the notch 64 is provided, and at the other end in the circumferential direction without the notch 64. Has two hole portions 68 formed at positions separated from each other in the axial direction (vertical direction in FIG. 7). In addition, the inner peripheral lid member 62 is preferably a press fitting, and bends the central portion in the long side direction of the blank punched into a rectangle in the thickness direction, and cuts out the notches 64 and the through holes 66, It can be obtained by punching out the hole 68.

The inner peripheral lid member 62 is radially overlapped with the inner peripheral surface of the orifice member 44. That is, the inner peripheral lid member 62 in the shape of a curved plate is overlapped with the central portion in the peripheral direction of the orifice member 44 having a thick wall, and the inner peripheral lid member 62 is in the shape of a flat plate. Both end portions in the circumferential direction of are overlapped with the step surface 50 of the orifice member 44.

Further, the protrusion 52 of the orifice member 44 is inserted into the hole 68 of the inner peripheral cover member 62, and the orifice member 44 and the inner peripheral cover member 62 are locked by the engagement between the protrusion 52 and the inner surface of the wall of the hole 68. Are relatively positioned in the circumferential and axial directions. Furthermore, the projecting tip of the projection 52, which is inserted into the hole 68 and projects further toward the inner circumference side than the inner circumference cover member 62, is crushed in the axial direction and expanded in diameter, whereby the inner circumference cover member is expanded. It is locked to the peripheral edge of the opening of the hole 68 in 62. By such caulking of the protrusion portion 52, the orifice member 44 and the inner peripheral lid member 62 are connected to each other, and the protrusion portion 52 and the inner peripheral lid member 62 are locked by the opening peripheral edge portion of the hole 68. The orifice member 44 and the inner peripheral lid member 62 are relatively positioned.

Further, the opening of the first recess 46 provided in the orifice member 44 is covered with the inner peripheral lid member 62 by the connection of the orifice member 44 and the inner peripheral lid member 62. A storage region 70 is formed by the first recess 46 between the members 62 in the radial direction.

A movable member 72 is arranged in the accommodation area 70. As shown in FIGS. 10 to 12, the movable member 72 is a plate-shaped rubber elastic body and is provided so as to surround the pressure receiving portion 74 having a substantially disc shape and the pressure receiving portion 74. An annular holding portion 76 having a larger thickness than that and a protruding piece 78 protruding from the holding portion 76 to the outer peripheral side are integrally provided.

The movable member 72 is inserted and arranged in the first recess 46 of the orifice member 44, and when the inner peripheral lid member 62 is attached to the orifice member 44, the sandwiching portion 76 of the movable member 72 is moved to the orifice member 44. And the inner peripheral cover member 62 is sandwiched between the inner peripheral cover member 62 and the inner peripheral cover member 62. Further, the pressure receiving portion 74 of the movable member 72 is arranged so as to cover the opening of the second recess 48, and the through holes 66, 66 of the inner peripheral lid member 62 are opened toward the pressure receiving portion 74. It is located in. As described above, the movable member 72 is arranged between the orifice member 44 and the inner peripheral lid member 62 in the radial direction, so that the accommodation area 70 is partitioned by the movable member 72. Also, through holes 66, 66 are connected to the inner peripheral lid member 62 side, and an intermediate communication hole 58 is connected to the orifice member 44 side with respect to the movable member 72.

As shown in FIGS. 1 and 2, the orifice assembly 42 having such a structure is arranged so as to extend in the circumferential direction on the inner circumference of the outer tubular member 14, and the intermediate tubular member 22 and the outer tubular member 14 are provided. It is supported radially. That is, the orifice assembly 42 is arranged so as to straddle the window portion 24 of the intermediate tubular member 22 in the circumferential direction, and both ends in the circumferential direction are one of the pair of groove-like portions 26, 26 of the intermediate tubular member 22. And both ends in the circumferential direction are sandwiched between the intermediate tubular member 22 and the outer tubular member 14 in the radial direction.

Here, the abutting portions 38 of the main rubber elastic body 16 fixed to the opening edge portion of the window portion 24 of the intermediate tubular member 22 are vertically arranged at both ends in the circumferential direction of the inner peripheral lid member 62 in the orifice assembly 42. Contact from the inner peripheral side in the direction. In the present embodiment, the abutting portion 38 of the main rubber elastic body 16 is pressed against the abutting flat surfaces 63 provided on the inner circumferential surfaces of both circumferential end portions of the inner circumferential lid member 62. The contact plane 63 extends substantially orthogonal to the direction in which the orifice member 44 and the inner peripheral cover member 62 are overlapped, in other words, the direction in which the contact portion 38 contacts the inner peripheral cover member 62. ..

As described above, since the contact portion 38 of the main rubber elastic body 16 is in contact with the contact plane 63 of the inner peripheral lid member 62, even if the locking and fixing by the protrusion 52 is released, the orifice member Separation of the inner peripheral cover member 62 and the inner peripheral cover member 62 is prevented by the contact portion 38 of the main rubber elastic body 16, and the orifice member 44 and the inner peripheral cover member 62 contact the contact portion 38 of the main rubber elastic body 16. Is positioned by.

In the present embodiment, the contact portion 38 of the main rubber elastic body 16 is pressed against both circumferential end portions of the inner peripheral lid member 62, and the inner peripheral lid member 62 contacts the contact portion 38. The elasticity of 38 urges the orifice member 44 toward the side. The contact portion 38 of the main rubber elastic body 16 is in contact with the inner peripheral lid member 62 at a position outside the protruding portion 52, and is also in contact with the tip end surface of the protruding portion 52.

Further, since the orifice assembly 42 covers the opening of the window portion 24, a fluid chamber 80 is formed between the orifice assembly 42 and the inner wall surface of the pocket portion 34 of the main rubber elastic body 16. The fluid chamber 80 is filled with an incompressible fluid, and part of the wall portion is formed by the main rubber elastic body 16. When vibration is input between the inner shaft member 12 and the outer tubular member 14, Internal pressure fluctuation is caused. The incompressible fluid sealed in the fluid chamber 80 is not particularly limited, but water, ethylene glycol, alkylene glycol, polyalkylene glycol, silicone oil, or a mixed solution thereof is preferably adopted. In order to advantageously obtain the vibration damping effect based on the flow action of the fluid, which will be described later, it is desirable that the fluid has a low viscosity of 0.1 Pa·s or less.

Further, since the fluid chamber 80 is connected to the inner peripheral lid member 62 side of the accommodation area 70 with respect to the movable member 72 in the accommodation area 70 by the through holes 66, 66, the inner peripheral lid member 62 of the accommodation area 70 is closer to the inner peripheral lid member 62. The same incompressible fluid as the fluid chamber 80 is sealed on the side.

Further, a pair of orifice assemblies 42, 42 are attached to the intermediate tubular member 22 from both sides in the radial direction, and the pair of orifice assemblies 42, 42 straddle each one of the pair of window portions 24, 24 in the circumferential direction. It is arranged as follows. Further, the first circumferential groove 54 of the one orifice assembly 42 has one end portion in the circumferential direction connected to the second circumferential groove 56 of the other orifice assembly 42 in the circumferential direction, and the other circumferential direction. Is connected to the first circumferential groove 54 of the other orifice assembly 42 in the circumferential direction. Furthermore, the second circumferential groove 56 of the one orifice assembly 42 is circumferentially connected to the first circumferential groove 54 of the other orifice assembly 42 at the circumferential end. As a result, each of the first circumferential groove 54 and the second circumferential groove 56 of the pair of orifice assemblies 42, 42 is continuous in the circumferential direction, and extends as a whole about one round. Each of the orifice members 44 of the pair of orifice assemblies 42, 42 is provided in the groove-like portion 26 between the openings of the first circumferential groove 54 and the second circumferential groove 56 on the circumferential end face in the axial direction. The contact projection 32 is pressed in a fluid-tight manner. Further, in the present embodiment, the pair of orifice assemblies 42, 42 have a common structure, and the manufacturing cost is reduced by facilitating the design and reducing the types of molds.

Further, each of the orifice members 44 of the pair of orifice assemblies 42, 42 extends in the circumferential direction along the outer tubular member 14, and the outer peripheral surfaces of the orifice members 44, 44 are covered by the outer tubular member 14. The outer peripheral opening of each of the first peripheral groove 54 and the second peripheral groove 56 is closed by the outer tubular member 14. As a result, a tunnel-shaped flow passage extending in the circumferential direction between the orifice members 44, 44 and the outer tubular member 14 is formed, and the flow passage forms the orifice passage 82 of the present embodiment. The orifice passage 82 is filled with an incompressible fluid, as is apparent from the fact that it is connected to the fluid chamber 80 as described later. Further, as can be seen from the fact that the incompressible fluid is connected to the orifice passage 82, the incompressible fluid is also sealed in the accommodation area 70 on the outer peripheral side of the movable member 72.

As the orifice passage 82, three passages having different tuning frequencies are set. That is, since both ends of the orifice passage 82 are communicated with one of the pair of fluid chambers 80, 80 through the end communication holes 60, 60, the low frequency that communicates the pair of fluid chambers 80, 80 with each other. It has a passage. Further, since the orifice passage 82 is connected to the orifice member 44 side of the accommodation area 70 through the intermediate communication hole 58 in the circumferential direction, the fluid chamber 80 and the accommodation area 70 are communicated with each other. In addition to providing a high frequency passage, a high frequency passage that connects the accommodation regions 70, 70 to each other is provided. In short, the orifice passage 82 is connected to the accommodating regions 70, 70 of the pair of fluid chambers 80, 80 and the pair of orifice assemblies 42, 42, respectively, and is provided in each of the low frequency passage, the medium frequency passage, and the high frequency passage. The fluid flow is appropriately generated according to the frequency of the input vibration.

The three passages set in the orifice passage 82 are adjusted by adjusting the ratio of the passage cross-sectional area (A) to the passage length (L) in consideration of the wall spring rigidity, thereby tuning the resonance frequency of the fluid flowing inside. The frequency is set, and in the present embodiment, the low-frequency passage, the medium-frequency passage, and the high-frequency passage having different tuning frequencies are set due to the difference in passage length. However, by adjusting the wall spring rigidity of the fluid chamber 80 and the housing region 70, for example, the tuning frequencies of the three passages set in the orifice passage 82 are all set to be the same, or the tuning frequencies of the two passages are set to the same. It is possible to set the same and to set the tuning frequency of the other passage to a frequency different from them.

In the suspension bush 10 having the structure according to the present embodiment as described above, when vibration is input in the radial direction in which the pair of fluid chambers 80, 80 are installed in the vehicle, when the vibration is input, the orifice passage is changed according to the frequency of the input vibration. A fluid flow is generated at 82, and a vibration damping effect based on a fluid action such as a resonance action of the fluid is exhibited. The area on the inner peripheral cover member 62 side of the accommodation area 70 that is in communication with the fluid chamber 80 through the through hole 66 is a movable member relative to the area on the orifice member 44 side of the accommodation area 70 that is connected to the orifice passage 82. Since it is partitioned by 72, the pressure receiving portion 74 of the movable member 72 is slightly deformed in the thickness direction when a small-amplitude vibration of medium to high frequencies is input, so that the fluid chamber 80 and the orifice member 44 of the accommodation region 70 are deformed. The hydraulic pressure is transmitted to and from the side. On the other hand, when the low-frequency large-amplitude vibration is input, the deformation of the pressure receiving portion 74 of the movable member 72 cannot be completely followed up, and the hydraulic pressure of the fluid chamber 80 is not transmitted to the accommodating region 70, and passes through the low-frequency passage in the orifice passage 82. The fluid flow is efficiently induced.

When a vibration having a remarkably large amplitude is input in the radial direction in which the pair of fluid chambers 80, 80 are arranged, the stopper rubber 36 of the main rubber elastic body 16 moves to the inner peripheral lid member 62 as shown in FIG. It abuts and is compressed. As a result, the amount of relative displacement between the inner shaft member 12 and the outer tubular member 14 is limited, and damage or the like due to excessive deformation of the main rubber elastic body 16 is prevented.

Further, in a state where the stopper rubber 36 is in contact with the inner peripheral cover member 62, as shown in FIG. Even if the protrusion 52 is destroyed by the shearing force acting on the protrusion 52 connecting the inner peripheral cover member 62, the inner peripheral lid member 62 is urged toward the orifice member 44 by the contact portion 38 of the main rubber elastic body 16. As a result, the orifice member 44 and the inner peripheral lid member 62 are held in a state of being superposed on each other. As a result, the orifice member 44 and the inner peripheral lid member 62 are prevented from being separated from each other, so that the movable member 72 is held in a state of being supported between the orifice member 44 and the inner peripheral lid member 62, and the desired protection is achieved. Vibration performance is maintained. In this way, even if the protrusion 52 that connects the orifice member 44 and the inner peripheral lid member 62 by caulking is damaged, the orifice member 44 and the inner peripheral portion due to the contact between the main rubber elastic body 16 and the inner peripheral lid member 62. Since the positioning of the lid member 62 functions as a fail safe, excellent reliability is realized.

Moreover, since the contact portion 38 of the main rubber elastic body 16 is in contact with the inner peripheral lid member 62, the force exerted from the stopper rubber 36 to the inner peripheral lid member 62 is not limited to the protrusion 52 but the contact portion. Since it is also shared and supported by 38, the force acting on the protrusion 52 is reduced, and the protrusion 52 is less likely to be damaged.

In addition, the contact portion 38 of the main body rubber elastic body 16 is brought into contact with the inner peripheral lid member 62, and the effect such as the above-described improvement in reliability is obtained by setting the orifice assembly 42 to the main body rubber elastic body 16. Since it is exhibited by assembling to the integrally vulcanization molded article 28 of No. 1 and no special work such as caulking is required, the reliability is improved without increasing the number of manufacturing steps or the manufacturing cost. Etc. can be easily realized.

Further, in the present embodiment, since the protrusion 52 of the orifice member 44 is inserted into the hole 68 of the inner peripheral lid member 62, the protrusion 52 and the hole 52 are inserted in the direction orthogonal to the insertion direction of the protrusion 52. A positioning action is exhibited by the engagement with the inner wall surface of 68. As a result, the orifice member 44 and the inner peripheral lid member 62 are positioned even in the direction orthogonal to the stacking direction, and the desired vibration damping performance and the like can be obtained more stably.

Further, the projecting tip end of the projection 52 of the orifice member 44, which is inserted into the hole 68 of the inner peripheral cover member 62, is crushed and expanded in diameter, whereby the opening peripheral edge of the hole 68 of the inner peripheral cover member 62 is expanded. It is locked to the part. In this way, the projection 52 is locked to the inner peripheral cover member 62 by caulking, so that the connection state between the orifice member 44 and the inner peripheral cover member 62 is more advantageously maintained. In addition, even if the protrusion 52 is damaged and the connection between the orifice member 44 and the inner peripheral lid member 62 is released due to the caulking of the protrusion 52, the orifice member 44 and the inner peripheral lid member 62 are made of rubber elastic material. By contacting the inner peripheral lid member 62 of the body 16, the body 16 is held in a relatively positioned state.

Further, the protrusions 52 are inserted into the holes 68 formed at both ends in the circumferential direction of the inner peripheral cover member 62, and the abutting portions 38 of the main rubber elastic body 16 are disposed at both ends in the circumferential direction of the inner peripheral cover member 62. The portion abuts on the inner peripheral surface of the inner peripheral lid member 62. As a result, the positioning structure by abutting the main rubber elastic body 16 on the inner peripheral lid member 62 and the positioning structure by inserting the protrusion 52 into the hole 68 are both end portions in the circumferential direction of the inner peripheral lid member 62. Therefore, in the central portion in the circumferential direction of the inner peripheral lid member 62, a large degree of freedom in design is realized by forming the through holes 66, 66 that connect the fluid chamber 80 and the accommodation region 70.

Further, since the orifice member 44 and the inner peripheral lid member 62 are positioned at positions that are separated from each other in the circumferential direction, the orifice member 44 and the inner peripheral lid member 62 are held more stably in the positioned state.

Further, the contact planes 63, which are the portions of the inner peripheral surface of the inner peripheral cover member 62 with which the contact sections 38 of the main rubber elastic body 16 contact, are provided at both ends in the circumferential direction of the flat inner peripheral cover member 62. It is set and spreads in a direction substantially orthogonal to the contact direction (the vertical direction in FIG. 1) between the main rubber elastic body 16 and the inner peripheral lid member 62. As a result, even when the main body rubber elastic body 16 is pressed against the inner peripheral lid member 62, the main body rubber elastic body 16 is unlikely to move in the surface direction along the inner peripheral surface of the inner peripheral lid member 62, and the main body rubber elastic body 16 is prevented. It is possible to efficiently obtain the positioning action by the contact of the elastic body 16 with the inner peripheral lid member 62.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the specific description. For example, it is desirable that the contact portion of the main rubber elastic body 16 with respect to the inner peripheral cover member 62 is provided so as to contact both end portions in the circumferential direction of the inner peripheral cover member 62. You may make it contact|abut to the circumferential direction intermediate part or center part.

In the above-described embodiment, the structure in which the orifice member 44 and the inner peripheral lid member 62 are connected by caulking the protrusion 52 is illustrated, but the connecting structure between the orifice member 44 and the inner peripheral lid member 62 is not necessarily limited to caulking. For example, the protrusion 52 may be press-fitted into the hole 68 to be connected, or the orifice member 44 and the inner peripheral lid member 62 may be connected by welding or adhesion. Further, for example, in the orifice assembly 42, the orifice member 44 and the inner peripheral lid member 62 are not connected or are temporarily connected to each other by an adhesive or the like until the assembly is completed. The three-dimensional body 42 is attached to the integrally vulcanized molded product 28 and the outer tubular member 14, and the contact portion 38 of the main rubber elastic body 16 contacts the inner peripheral cover member 62, whereby the orifice member 44 and the inner peripheral cover member 62. May be held in the connected state only by the elasticity of the contact portion 38.

A pair of orifice assemblies including the orifice member do not necessarily have to be provided, and for example, one C-shaped orifice assembly may be adopted. Further, in the case of adopting the structure having the two orifice assemblies in the fluid filled tubular vibration damping device according to the present invention, one of the two orifice assemblies has the structure according to the present invention, and the other one has the other structure. A conventional structure can also be used.

In the above-described embodiment, the movable member 72, in which the holding portion 76 is held between the orifice member 44 and the inner peripheral lid member 62 and exerts the hydraulic pressure transmitting action by the elastic deformation of the pressure receiving portion 74, is exemplified. The movable member is a plate-like member formed of a hard member or an elastic body, and the movable member is disposed in the accommodation area 70 in such a manner that the displacement in the thickness direction is allowed. You may make it exhibit a transmission effect.

The present invention is applicable not only to suspension bushes, but also to fluid-filled tubular vibration damping devices used as engine mounts, subframe mounts, differential mounts, and the like. Further, the scope of application of the present invention is not limited to the fluid filled tubular vibration damping device for automobiles, but the fluid filled tubular vibration damping device used for motorcycles, railway vehicles, industrial vehicles and the like. Can also be suitably adopted.

10: Suspension Bush (Fluid Filled Cylindrical Vibration Isolator), 12: Inner Shaft Member, 14: Outer Tube Member, 16: Main Rubber Elastic Body, 42: Orifice Assembly, 44: Orifice Member, 52: Protrusion, 58: Intermediate communication hole (communication hole), 62: Inner peripheral lid member, 63: Contact plane (contact surface), 68: Hole portion, 70: Storage area, 72: Movable member, 80: Fluid chamber, 82: Orifice passage

Claims (5)

The inner shaft member and the outer tubular member are elastically coupled to each other by the main body rubber elastic body to form a fluid chamber in which an incompressible fluid is sealed, and the inner tubular member and the outer tubular member are circumferentially arranged in the circumferential direction. A fluid-filled tubular vibration damping device, wherein an extending orifice member is provided, and an orifice passage formed in the orifice member is connected to the fluid chamber,
An inner peripheral lid member is provided to be superposed on the inner peripheral surface of the orifice member, and a storage region in which an incompressible fluid is sealed is formed between the orifice member and the inner peripheral lid member, The accommodation member is partitioned into the orifice member side and the inner peripheral lid member side by a movable member arranged in the accommodation region, and the orifice member side of the accommodation region is communicated with the orifice passage. While the inner peripheral cover member side of the accommodation area is communicated with the fluid chamber through a communication hole penetrating the inner peripheral cover member,
A fluid-filled tubular vibration damping device characterized in that the orifice member and the inner peripheral lid member are positioned in the overlapping direction by the main rubber elastic body contacting the inner peripheral surface of the inner peripheral lid member. apparatus. The orifice member is formed with a protrusion protruding toward the inner peripheral side, and the inner peripheral lid member is formed with a hole corresponding to the protrusion, and the protrusion is inserted into the hole. The fluid filled cylindrical vibration damping device according to claim 1, wherein the orifice member and the inner peripheral lid member are positioned relative to each other. The orifice member and the inner peripheral lid member are connected by caulking the protruding tip end portion of the protrusion of the orifice member inserted into the hole of the inner peripheral lid member to the inner peripheral lid member by caulking. The fluid filled tubular vibration damping device according to claim 2. The hole portions are formed at both circumferential end portions of the inner peripheral lid member, and the main rubber elastic body is in contact with inner circumferential surfaces of both circumferential direction end portions of the inner circumferential lid member. 3. The fluid filled tubular vibration damping device according to item 3. 5. The contact surface of the main body rubber elastic body in the inner peripheral lid member is a flat surface that extends orthogonal to the overlapping direction of the orifice member and the inner peripheral lid member. A fluid-filled tubular vibration-damping device according to the item 1.

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