JP2008151215A - Fluid filled type cylindrical vibration controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid filled type cylindrical vibration controller of a novel structure forming a short circuit passage reducing or avoiding generation of excessive negative pressure in a fluid chamber by a simple structure without requiring a special member. <P>SOLUTION: A portion of an orifice member 46, fitted into a first support groove 32a, is circumferentially divided, at least one of both circumferentially divided ends of the orifice member 46 is formed with an inner surface recessed groove 72 opened to an inner peripheral surface, and the inner surface recessed groove 72 is covered with the bottom surface of the first support groove 32a. Thereby, while a short-circuit passage 74 is formed for allowing a first fluid chamber 68a and a second fluid chamber 68b to communicate each other, a valve element rubber 34 is provided to the first support groove 32a, the valve element rubber 34 overlaps the circumferential end surface of the orifice member 46 with the short circuit passage 74 opened, and the valve element rubber 34 is arranged to close one opening of the short-circuit passage 74. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid-filled cylindrical vibration isolator that obtains a vibration isolation effect by utilizing a vibration isolation characteristic that is exhibited based on a flow action or the like of an incompressible fluid sealed inside, For example, the present invention relates to a fluid-filled cylindrical vibration isolator that is applied to suspension bushes for automobiles, engine mounts, subframe mounts, body mounts, differential mounts, and the like.

  2. Description of the Related Art Conventionally, a fluid-filled cylindrical vibration isolator is known as a type of anti-vibration coupling body or anti-vibration support body interposed between members constituting a vibration transmission system. Such a fluid-filled cylindrical vibration isolator includes, for example, an inner shaft member and an intermediate sleeve that is arranged separately on the outer peripheral side thereof as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2006-2857). Are integrally connected to each other by a rubber elastic body to form an integrally vulcanized molded product, and the integrally vulcanized molded product has a plurality of pocket portions that open to the outer peripheral surface through a plurality of windows formed in the intermediate sleeve. In addition, the outer cylinder member is externally fitted and fixed to the intermediate sleeve to cover the openings of the plurality of pocket portions, and a plurality of fluid chambers filled with incompressible fluid are separated in the circumferential direction. It is structured. Further, an orifice passage is formed to communicate the plurality of fluid chambers with each other, and the orifices are connected between the plurality of fluid chambers based on relative pressure fluctuations between the fluid chambers caused by external load input. By causing the fluid flow through the passage, the intended vibration isolation effect is exhibited based on the fluid flow action.

  By the way, in such a fluid-filled cylindrical vibration isolator, relative fluid pressure fluctuations are generated between a plurality of fluid chambers by the input of a load, so that fluid flow through the orifice passage is generated. However, when the input load is a shocking large load, the fluid flow through the orifice passage may not follow, and a large negative pressure may be generated in the fluid chamber.

  Due to such a negative pressure in the fluid chamber, a gas dissolved in the incompressible fluid sealed in the fluid chamber appears as a gas phase, and bubbles that are understood as cavitation may be generated. And when the bubble which appeared appears, an explosive micro jet is formed, and the water hammer pressure by the micro jet is propagated to a vibration isolation target member such as a vehicle body via an inner shaft member, an outer cylinder member, etc. Therefore, it is considered that abnormal noise and vibration can be generated.

  Therefore, in order to reduce or avoid the negative pressure in the fluid chamber that causes such abnormal noise and vibration, in the fluid filled cylindrical vibration isolator described in Patent Document 1, a relief that short-circuits a plurality of fluid chambers. The flow path is formed by a passage member that is separate from the orifice member constituting the wall portion of the orifice passage. This relief flow path is substantially closed by an elastic valve body in a non-load input state or a normal load input state, and a large pressure difference between fluid chambers when a large load is input. The elastic valve body is deformed based on the above and is in a communication state. Therefore, if an excessive negative pressure is generated in the fluid chamber as described above, the relief flow path is brought into communication, and the negative pressure in the fluid chamber is quickly eliminated by the fluid flowing through the relief flow path. .

  However, in the fluid-filled cylindrical vibration isolator described in Patent Document 1, the passage member that forms the relief flow path is a separate member from the integral vulcanized molded product of the orifice member and the main rubber elastic body. Therefore, it is necessary to add and assemble a special member (passage member) for realizing the negative pressure eliminating action as described above. Therefore, there has been a problem that the complexity of the structure due to the increase in the number of parts and the complexity of the assembly work tend to be problems.

JP 2006-2857 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is a short-circuit path that can reduce or avoid the occurrence of excessive negative pressure in the fluid chamber. It is an object of the present invention to provide a fluid-filled cylindrical vibration isolator having a novel structure that can be realized with a simple structure without requiring a special member.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

  That is, the present invention includes an integrally vulcanized molded product in which a shaft member and an intermediate sleeve arranged apart from the outer periphery thereof are elastically connected by a main rubber elastic body, and an axial intermediate portion of the intermediate sleeve. The main body rubber elastic body is provided with first and second pocket portions that open to the outer peripheral surface through the first and second window portions formed in the outer cylinder member. Is inserted and fixed, thereby forming first and second fluid chambers in which the openings of the first and second pocket portions are fluid-tightly covered and sealed with incompressible fluid. In addition, first and second support grooves extending in the circumferential direction between the first and second fluid chambers are formed in the axially intermediate portion of the intermediate sleeve. An orifice member extending in the circumferential direction with respect to the support groove is fitted, and the orifice member is connected to the intermediate slot. The concave groove formed on the outer peripheral surface of the orifice member is covered with the outer cylinder member so as to communicate with the first and second fluid chambers. In the fluid-filled cylindrical vibration isolator in which the orifice passage is formed, a portion of the orifice member that is fitted into the first support groove is divided in the circumferential direction, and is divided in the circumferential direction of the orifice member. At least one of the both ends is formed with an inner groove that opens to the inner peripheral surface, and the inner groove is covered with the bottom surface of the first support groove, whereby the first fluid chamber and the second groove are covered. A short circuit passage is formed to communicate the fluid chambers of each other, while a valve body rubber is provided in the first support groove, and the valve body rubber surrounds the orifice member where the short circuit passage opens. One opening of the short-circuit passage is overlapped with the direction end face, and the valve body Characterized in that it is closed by arm.

  In such a fluid-filled cylindrical vibration isolator having a structure according to the present invention, a short-circuit passage that connects the fluid chambers to each other is formed, and a valve rubber is overlapped on one opening of the short-circuit passage. The opening is closed. As a result, when an excessive pressure difference is generated between the fluid chambers due to the vibration that the orifice passage cannot follow, and the pressure difference between the fluid chambers is generated, the valve rubber is elastically deformed based on the pressure difference between the fluid chambers. As a result, the short-circuit passage is communicated. The pressure difference between the fluid chambers is quickly eliminated by the fluid flow through the short-circuit passage. Therefore, it is possible to reduce or avoid the generation of a large negative pressure in the fluid chamber, and advantageously prevent the generation of abnormal noise and vibration that may be caused by water hammer pressure when bubbles appearing due to the negative pressure disappear. I can do it.

  Further, at the time of normal vibration input, the internal pressure fluctuation of the fluid chamber can be effectively obtained because the short circuit passage is closed by the valve body rubber. Accordingly, the amount of fluid that can be flowed between the fluid chambers through the orifice passage can be advantageously obtained, and an excellent vibration-proofing effect based on a fluid action such as a resonance action of the fluid can be effectively exhibited.

  Furthermore, in the present invention, the short-circuit passage is formed using an orifice member. Therefore, it is possible to realize a vibration isolator having the above excellent effects with a simple structure and a small number of parts without providing any special parts for forming a short-circuit path. Further, by avoiding an increase in the number of parts, it can be easily manufactured with a small number of steps.

  In the fluid-filled cylindrical vibration isolator according to the present invention, both ends of the orifice member that are fitted in the first support groove are divided in the circumferential direction and divided in the circumferential direction of the orifice member. The inner surface is provided with inner grooves formed on the inner peripheral surface, and the inner grooves are covered with the bottom surfaces of the first support grooves, whereby the first fluid chamber and the second fluid are formed. The first and second short-circuit passages for communicating the chambers are formed independently of each other, while the first support groove is provided with first and second valve body rubbers, The valve body rubber is superposed on the circumferential end surface of the orifice member where the first short-circuit passage opens, and the second valve body rubber is overlapped in the circumferential direction of the orifice member where the second short-circuit passage opens. An opening on the second fluid chamber side of the first short-circuit path is overlaid on the end face, Together are closed by the valve body rubber, structure openings of the first fluid chamber side of the second short-circuit passage is closed by said second valve body rubber may be adopted.

  By adopting such a structure, either the first fluid chamber or the second fluid chamber is selectively communicated with either one of the first fluid chamber and the second fluid chamber, regardless of whether the pressure is negative. By setting the state, the negative pressure generated in the fluid chamber can be quickly eliminated. Note that such a structure having two independent short-circuit passages is, for example, a fluid-filled cylindrical vibration isolator in which both the first and second fluid chambers are pressure receiving chambers that generate pressure fluctuations when vibration is input. The present invention is preferably applied to the apparatus.

  In the fluid-filled cylindrical vibration isolator according to the present invention, the first support groove is provided with an elastic seal protrusion protruding from the bottom surface, and the elastic seal protrusion is divided in the circumferential direction. A structure that is sandwiched between both end portions of the member and is sandwiched between the bottom surface of the first support groove and the outer cylindrical member so that the end portions of the orifice member are fluid-tightly sealed. It can also be adopted.

  By adopting such a structure, the first support groove is closed under the closed state of the short-circuit path by sealing between the circumferential ends of the orifice member by the elastic seal protrusion. As a result, the amount of fluid flow through the orifice passage at the time of normal vibration input can be advantageously obtained, and the intended vibration isolation effect can be effectively exhibited.

  In the fluid-filled cylindrical vibration isolator having a structure according to the present invention, a contact portion that protrudes into the first support groove is provided on the side wall portion of the circumferential intermediate portion of the first support groove. It is also possible to adopt the structure that is used.

  In the fluid-filled cylindrical vibration isolator having such a structure, the orifice member can be positioned in the circumferential direction by bringing the circumferential end of the orifice member into contact with the contact portion from both sides in the circumferential direction. . Therefore, the orifice member can be easily aligned and assembled at a predetermined circumferential position.

  Furthermore, in the fluid-filled cylindrical vibration isolator having the structure according to the present invention as described above, a buffer recess that opens toward the inside of the first support groove is formed in the circumferential intermediate portion of the contact portion. Also good.

  According to this, when the circumferential end portion of the orifice member is pressed against the contact portion, the stress transmitted through the contact portion between the circumferential end portions of the orifice member is absorbed by the buffer recess. It has become so. Thereby, for example, even when the orifice member is composed of a plurality of members, it is possible to prevent displacement due to transmission stress. In addition, since the buffer recess is formed in the middle portion of the contact portion in the circumferential direction, the spring constant in the circumferential direction of the contact portion is reduced. As a result, when the circumferential end of the orifice member is pressed against the contact portion, shock-absorbing contact can be realized, and deformation or breakage of the orifice member can be prevented. In addition, by providing a buffer recess to prevent stress transmission between the circumferential ends of the orifice member, the contact between the orifice member and the valve body rubber in the circumferential direction can be realized with a stable abutment force. I can do it.

  In the fluid-filled cylindrical vibration isolator having a structure according to the present invention, the valve body rubber is overlaid so as to be in pressure contact with a circumferential end surface of the orifice member where the short-circuit passage of the orifice member opens. A structure may be adopted.

  According to such a structure, the closing of the short circuit passage by the valve body rubber can be realized more advantageously. As a result, it is possible to effectively obtain a vibration isolation effect during normal vibration input. Note that the contact force of the valve rubber against the orifice member effectively realizes switching of the short-circuit path when no vibration load is input and when normal vibration is input, and switching of the short-circuit path when shocking large loads are input. Adjusted to get.

  Further, in the fluid-filled cylindrical vibration isolator according to the present invention, the orifice member is composed of a pair of orifice forming members, and circumferential ends of the pair of orifice forming members are connected to the first support groove. A structure that is fitted in each of the second support grooves can also be employed.

  Thus, by comprising an orifice member by a pair of orifice formation member, an orifice member can be easily assembled | attached with respect to the integral vulcanization molded product of a main body rubber elastic body. Furthermore, by fitting the end portions in the circumferential direction of the pair of orifice forming members into the first and second support grooves, each orifice forming member can be stably fixed to the integrally vulcanized molded product.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIGS. 1 and 2 show a vibration isolating bush 10 which is an embodiment of a fluid-filled cylindrical vibration isolator having a structure according to the present invention. The anti-vibration bush 10 includes an inner cylinder 12 as an axial member and an outer cylinder 14 as an outer cylinder positioned at a predetermined distance from each other in the radial direction. The inner cylindrical metal member 12 and the outer cylindrical metal member 14 are elastically connected by the main rubber elastic body 16 interposed between the 14 radial directions. The anti-vibration bushing 10 is interposed between the anti-vibration connected members by attaching the inner cylinder fitting 12 and the outer cylinder fitting 14 to each of the anti-vibration connection members. ing.

  More specifically, the inner cylinder fitting 12 has a thin, small-diameter, generally cylindrical shape, and is a rigid material formed of, for example, an aluminum alloy. In addition, one end (the upper end in FIG. 1) of the inner cylindrical metal member 12 in the axial direction is bent outward in the direction perpendicular to the axis, and a flange 18 that extends outward in the direction perpendicular to the axis is integrally formed. Has been.

  Further, a stopper member 19 is fixed to the inner cylinder fitting 12. The stopper member 19 has a substantially rectangular block shape and is formed of a hard synthetic resin material. The stopper member 19 is externally fitted and fixed at the central portion in the axial direction of the inner cylindrical metal member 12 and protrudes toward both sides in one radial direction, and the protruding tip surface is a curved surface curved in the circumferential direction. It is said that.

  Further, a metal sleeve 20 as an intermediate sleeve is disposed on the outer peripheral side of the inner cylindrical metal member 12 at a predetermined distance in the radial direction. The metal sleeve 20 has a thin, large-diameter, generally cylindrical shape, and is disposed so as to surround the inner cylinder fitting 12 over the entire circumference. Further, the metal sleeve 20 in the present embodiment has a smaller axial dimension than the inner cylindrical metal member 12, and the inner cylindrical metal member 12 protrudes outward in the axial direction from both axial ends of the metal sleeve 20. .

  Further, the substantially central portion in the axial direction of the metal sleeve 20 has a smaller diameter than both end portions in the axial direction, and is a small diameter portion 22 integrated with both end portions in the axial direction via a pair of stepped portions. .

  Further, the small-diameter portion 22 of the metal sleeve 20 includes a first opening window 24a as a first window portion and a second opening window 24b as a second window portion with a predetermined distance in the circumferential direction. Is formed. The first and second opening windows 24 a and 24 b are provided so as to face each other in one radial direction, and are formed through the small diameter portion 22 of the metal sleeve 20. The first and second opening windows 24a and 24b have a substantially rectangular shape and extend in the circumferential direction by a predetermined length, and both edges in the axial direction are positioned at both axial ends of the small diameter portion 22. Extends to the outer peripheral edge of the stepped portion. Thereby, between the circumferential direction edge part of 1st, 2nd opening window 24a, 24b, the 1st circumferential groove 26a opened to an outer peripheral surface by using the small diameter part 22 and a pair of level | step-difference part as a wall surface, and a 2nd circumference A groove 26b is formed.

  A main rubber elastic body 16 is interposed between the inner cylinder fitting 12 and the metal sleeve 20. The main rubber elastic body 16 has a thick, substantially cylindrical shape, and its inner peripheral surface is fixed to the outer peripheral surface of the inner cylindrical metal member 12 and its outer peripheral surface is fixed to the inner peripheral surface of the metal sleeve 20. Thus, the inner cylinder fitting 12 and the metal sleeve 20 are elastically connected via the main rubber elastic body 16. Thus, in the present embodiment, as shown in FIG. 3, the main rubber elastic body 16 is formed as an integral vulcanized molded product 28 including the inner cylinder fitting 12 and the metal sleeve 20.

  Further, the main rubber elastic body 16 according to the present embodiment has a straight portion 29 on both sides of the inner cylindrical metal fitting 12 in one radial direction where the first circumferential groove 26a and the second circumferential groove 26b face each other. Is formed. The straight portion 29 is formed with a predetermined length in the circumferential direction, and is formed so as to penetrate the radial intermediate portion of the main rubber elastic body 16 in the axial direction, as shown in FIG. .

  Further, the stopper member 19 fixed to the inner cylinder fitting 12 is covered on the entire surface thereof with a rubber layer integrally formed with the main rubber elastic body 16. Further, a radially extending front end surface of the stopper member 19 fixed to the inner cylindrical metal fitting 12 is formed with a recess extending in the axial central portion over substantially the entire length in the circumferential direction. A stopper rubber 30 is formed so as to protrude at the end. The stopper rubber 30 is integrally formed with the main rubber elastic body 16, extends in the circumferential direction with a substantially constant rectangular cross section, and is radially outward from the radially projecting tip surfaces at both axial end portions of the stopper member 19. It is provided so as to protrude. In this embodiment, the rubber layer formed so as to cover both end portions in the circumferential direction of the radially projecting tip surface of the stopper member 19 is formed with a number of concave grooves extending in the circumferential direction. Thereby, when the inner cylinder fitting 12 and the outer cylinder fitting 14 are relatively displaced in the radial direction by the vibration input, and the stopper member 19 is brought into contact with an orifice member to be described later, buffering contact is realized. Thus, problems such as breakage of the orifice member can be avoided.

  A covering rubber layer 31 is provided in the first and second circumferential grooves 26 a and 26 b in the metal sleeve 20. The covering rubber layer 31 is a thin rubber layer integrally formed with the main rubber elastic body 16, and is attached so as to cover the groove inner surfaces of the first and second circumferential grooves 26a and 26b over substantially the entire surface. Is formed. As described above, the inner surfaces of the first and second circumferential grooves 26a and 26b are entirely covered with the covering rubber layer 31, whereby the first and second support grooves 32a and 32b in the present embodiment are formed. Yes. In the present embodiment, in the covering rubber layer 31, the portions fixed to the side wall portions of the first and second circumferential grooves 26a and 26b are the bottom wall portions of the first and second circumferential grooves 26a and 26b. It is thicker than the part fixed to.

  Further, an elastic seal protrusion 33 integrally formed with the covering rubber layer 31 is formed on the bottom surface of the first support groove 32a. The elastic seal protrusion 33 has a substantially constant rectangular cross section at the center portion in the circumferential direction and width direction (bush central axis direction) of the first support groove 32a, and radially outward from the bottom surface of the first support groove 32a. It is formed so as to protrude. Further, the elastic seal protrusion 33 is formed so as to protrude with a height substantially the same as the radial dimension of the side wall portion of the first support groove 32a.

  Furthermore, the 1st elastic valve body 34a and the 2nd elastic valve body 34b as valve body rubber | gum are provided in the bottom face of the 1st support groove | channel 32a. The first and second elastic valve bodies 34a and 34b are integrally formed with the covering rubber layer 31 deposited on the inner surface of the first support groove 32a, and have a substantially diameter from the bottom surface of the first support groove 32a. It is formed so as to protrude outward in the direction. The first elastic valve body 34a and the second elastic valve body 34b have substantially the same trapezoidal block shape and are provided in opposite directions in the circumferential direction. Further, the first and second elastic valve bodies 34a and 34b are provided on both sides of the elastic seal protrusion 33 sandwiched in the groove width direction (mount axis direction). Further, one end surface in the circumferential direction of the first elastic valve body 34a and the other end surface in the circumferential direction of the second elastic valve body 34b are both formed so as to expand in a substantially radial direction, and the elastic seal protrusion It is aligned with the circumferential end face of 33 in the circumferential direction.

  The first and second elastic valve bodies 34a and 34b in the present embodiment are slightly separated from the side wall surface of the first support groove 32a and the end surface in the groove width direction of the elastic seal protrusion 33, and It is formed with a protruding height that is slightly smaller than the radial dimension of the side wall of one support groove 32 a, and is positioned on the inner peripheral side of the outer peripheral surface of both end portions in the axial direction of the metal sleeve 20.

  Moreover, the fitting recessed part 36 is formed in the side wall part of the 1st support groove | channel 32a. The fitting recess 36 is formed on the covering rubber layer 31 formed on the side wall portion of the first support groove 32a at the circumferential intermediate portion of the first support groove 32a. It is provided so as to open. The fitting recess 36 has a recess shape extending in the radial direction, and is opened on the outer peripheral surface of the covering rubber layer 31.

  Further, a notch 38 is formed in the side wall of the first support groove 32a. The notch 38 is formed in the covering rubber layer 31 that is deposited on the side wall of the first support groove 32a at the circumferential end of the first support groove 32a.

  Further, in the side wall portion of the first support groove 32 a, a portion located between the fitting recess 36 and the notch 38 in the circumferential direction is a contact portion 40. The contact portion 40 is a part of the covering rubber layer 31 constituting the side wall surface of the first support groove 32a by forming the fitting recess 36 and the notch 38 in the side wall portion of the first support groove 32a. And formed so as to protrude toward the inside of the first support groove 32a over a predetermined length in the circumferential direction.

Further, a buffer recess 42 is formed in the circumferential intermediate portion of the contact portion 40. The buffer recess 42 is formed to open to the inner surface side (axially inner side) of the first support groove 32a and continuously extend over the entire length in the groove depth direction (radial direction). By forming the buffer recess 42 in the middle portion of the contact portion 40 in the circumferential direction, the contact portion 40 is divided in the circumferential direction with the buffer recess 42 interposed therebetween. In the present embodiment, the buffer recess 42 is formed with a smaller circumferential dimension than the fitting recess 36, and the buffer recess 42, the fitting recess 36, and the notch 38 are all substantially equal in the axial direction. It is formed to become. Furthermore, in the present embodiment, the separation distance l _{a in} the circumferential direction between the buffer recess 42 and the fitting recess 36 is sufficiently larger than the separation distance l _{b in} the circumferential direction between the buffer recess 42 and the notch 38. The rubber elastic body located between the buffer recess 42 and the notch 38 in the circumferential direction is relatively thin in the circumferential direction.

  The fitting recess 36, the buffer recess 42, and the notch 38 are formed on the side wall portion on the one side in the axial direction of the first support groove 32a (the upper side wall portion in FIG. 3) and the side wall on the other side in the axial direction. It is formed in each part (lower wall part in FIG. 3). Further, the first fitting recess 36a, the first buffer recess 42a, and the first notch 38a formed on the side wall portion on one axial side of the first support groove 32a (upper side in FIG. 3) , With respect to the second fitting recess 36b, the second buffer recess 42b, and the second notch 38b formed on the side wall on the other axial side (the lower side in FIG. 3) in the circumferential direction. The arrangement order is reversed.

  Further, in the present embodiment, the fitting recess 36 and the buffer recess 42 are formed so as to be positioned with the elastic valve body 34 interposed therebetween in the circumferential direction. That is, in the present embodiment, the first fitting recess 36a is formed on one side in the circumferential direction (left side in FIG. 3) sandwiching the first elastic valve body 34a in the side wall on one side in the axial direction. In addition, the first buffer recess 42a is formed on the other side in the circumferential direction (right side in FIG. 3), while the second elastic valve body 34b is sandwiched in the side wall on the other side in the axial direction. A second buffer recess 42b is formed on one side, and a second fitting recess 36b is formed on the other circumferential side.

  In addition, a first pocket portion 44a and a second pocket portion 44b are formed at the central portion in the axial direction of the main rubber elastic body 16 so as to be opposed to each other in one radial direction with the inner cylinder fitting 12 interposed therebetween. Has been. The first and second pocket portions 44a and 44b are formed so as to face each other in one radial direction substantially perpendicular to the radial direction in which the first and second support grooves 32a and 32b face each other. The first and second opening windows 24a and 24b are formed on the outer peripheral surface. Further, since the first and second pocket portions 44a and 44b are formed, the axial straight section of the main rubber elastic body 16 at the central portion in the axial direction has a substantially rectangular shape. The circumferential grooves 26a and 26b are formed so as to extend substantially linearly in the radial direction between the bottom wall portions.

  Moreover, as shown in FIGS. 4 and 5, the integrally vulcanized molded product 28 of the main rubber elastic body 16 spans between the first pocket portion 44 a and the second pocket portion 44 b in the circumferential direction. An orifice member 46 is assembled. In this embodiment, the orifice member 46 is configured by combining the first orifice forming member 48a and the second orifice forming member 48b with each other in the circumferential direction, and is bent in a substantially C shape with a length of slightly less than one turn. It is formed to extend.

  The orifice forming member 48 is formed of, for example, a hard synthetic resin reinforced with fiber, and as shown in FIGS. Yes. In addition, support portions 50 projecting on both sides in the width direction (upper and lower sides in FIG. 7) of the orifice forming member 48 are provided at the intermediate portion in the circumferential direction of the orifice forming member 48. It is larger than both ends in the circumferential direction.

  Further, at one end portion in the circumferential direction of the orifice forming member 48, both end portions in the width direction extend in the circumferential direction as compared with the central portion in the width direction. As a result, an arm-shaped support arm 52 is formed on one end side in the width direction (upper side in FIG. 6) and supported on the other end side in the width direction (lower side in FIG. 6). A protrusion 54 that is thicker in the width direction than the arm 52 is formed. In other words, one end (right in FIG. 7) in the circumferential direction of the orifice forming member 48 in the present embodiment has a shape in which the central portion in the width direction is cut into a substantially rectangular shape.

  Further, a passage forming portion 56 is provided at the distal end portion of the support arm portion 52. The passage forming portion 56 is formed so as to protrude from the circumferential front end portion of the support arm portion 52 toward the center in the width direction, and has a substantially rectangular block shape as a whole. The length of the support arm 52 in the circumferential direction is larger than that of the protrusion 54, and the support arm 52 extends outward in the circumferential direction from the protrusion 54. Accordingly, the passage forming portion 56 provided at the protruding tip portion of the support arm portion 52 is positioned so as to be separated from the protruding portion 54 on the outer side in the circumferential direction.

  Furthermore, in the present embodiment, the fitting portion in which the end portion on the outer side in the width direction (upper side in FIG. 6) of the passage forming portion 56 protrudes outward from the end portion on the outer side in the width direction of the support arm portion 52. 58. The fitting portion 58 has a circumferential dimension substantially equal to that of the passage forming portion 56, and has a projecting height sufficiently smaller than the passage forming portion 56 in the width direction, and is opposite to the passage forming portion 56 in the axial direction. It is formed so as to protrude toward.

  Further, in the orifice forming member 48, the end portion positioned on the opposite side in the circumferential direction from the side on which the support arm portion 52 and the protruding portion 54 are formed has its circumferential end surface substantially orthogonal to the circumferential direction. The flat surface is widened.

  Further, the orifice forming member 48 is formed with a concave groove 60 extending in the center portion in the width direction (up and down in FIG. 6) over the entire length in the circumferential direction. The concave groove 60 is formed on the outer peripheral surface of the orifice forming member 48 so as to extend in the circumferential direction with a substantially constant groove cross-sectional shape over the entire length in the circumferential direction. 48 is opened at one end portion in the circumferential direction at the central portion in the axial direction (upper and lower in FIG. 6). Further, in the present embodiment, the concave groove 60 has a substantially V-shaped groove shape that gradually widens toward the outer peripheral side.

  As shown in FIGS. 4 and 5, the orifice forming member 48 having the concave groove 60 is assembled to the integral vulcanization molded product 28 so as to extend on the opening of the pocket portion 44. More specifically, the circumferential end portions of the support arm 52 and the protruding portion 54 formed at one end in the circumferential direction of the orifice forming member 48 and the passage forming portion 56 are fitted into the first support groove 32a. At the same time, the other end in the circumferential direction of the orifice forming member 48 is fitted into the second support groove 32b, so that the orifice forming member 48 is disposed so as to straddle the pocket portion 44 in the circumferential direction.

  In the present embodiment, a pair of support portions 50 and 50 projecting on both sides in the axial direction are formed in the intermediate portion of the orifice forming member 48 in the circumferential direction, and the axial dimension of the orifice forming member 48 at the location where the support portion 50 is formed is The axial dimension of the opening window 24 is substantially equal. Thereby, when the orifice forming member 48 is assembled to the integrally vulcanized molded product 28, the orifice forming member 48 is easily positioned in the axial direction, and the portion of the orifice forming member 48 that straddles the pocket portion 44 is the metal sleeve 20. It is fitted to the opening window 24 and is supported in the axial direction.

  Also, as shown in FIG. 4, a pair of orifice forming members 48 are assembled so as to be substantially opposed to the integrally vulcanized molded product 28 in one direction perpendicular to the axis with the inner cylinder fitting 12 interposed therebetween. . That is, as shown in FIG. 4, the first orifice forming member 48a is disposed so as to straddle the first pocket portion 44a in the circumferential direction, and the second orifice forming member 48b is provided in the second direction. It arrange | positions so that the pocket part 44b may be straddled in the circumferential direction.

  In the present embodiment, the first orifice forming member 48a and the second orifice forming member 48b are members having the same shape and are assembled at a predetermined position as described above, whereby the support arm portion 52 is assembled. The protrusions 54 are assembled so that their positions are opposite to each other in the axial direction (up and down in FIG. 4 which is the width direction of the orifice forming member 48). Accordingly, the first passage forming portion 56a provided in the first orifice forming member 48a and the second projecting portion 54b provided in the second orifice forming member 48b are opposed to each other at a predetermined distance in the circumferential direction. The first projecting portion 54a provided on the first orifice forming member 48a and the second passage forming portion 56b provided on the second orifice forming member 48b are spaced apart from each other by a predetermined distance. Are opposed to each other.

  Further, in the assembled state of the first and second orifice forming members 48a and 48b as described above, the first orifice forming member 48a and the second orifice forming member 48b fitted in the second support groove 32b. The ends are brought into contact with each other in the circumferential direction. Thus, the first orifice forming member 48a and the second orifice forming member 48b are assembled so as to be continuous in the circumferential direction, and the orifice member 46 in the present embodiment is combined with the first orifice forming member 48a and the second orifice forming member 48a. The orifice forming member 48b is used.

  Furthermore, the first concave groove 60a formed in the first orifice forming member 48a and the second concave groove 60b formed in the second orifice forming member 48b are connected on the second support groove 32b. In addition, a circumferential groove 62 is formed in the outer circumferential surface of the orifice member 46 and continuously extending in the circumferential direction with a predetermined length.

  The first passage forming portion 56a provided in the first orifice forming member 48a and the second passage forming portion 56b provided in the second orifice forming member 48b are arranged on the first support groove 32a. They are arranged at a predetermined distance in the circumferential direction. Thereby, the orifice member 46 is divided | segmented by the circumferential direction in the part inserted by the 1st support groove | channel 32a.

  Further, as shown in FIG. 4, the fitting portion 58 formed integrally with the passage forming portion 56 is fitted into the fitting recess 36 formed on the side wall surface of the first support groove 32a. The protrusion 54 provided on the opposite side of the support arm 52 in the axial direction is fitted into the notch 38 formed on the side wall surface of the first support groove 32a. Thereby, the fitting part 58 and the protrusion part 54 are made to contact | abut with respect to the contact part 40 in the circumferential direction, and the orifice member 46 is positioned in the circumferential direction. That is, in the present embodiment, the first fitting portion 58a is fitted into the first fitting recess 36a, and the first projecting portion 54a is fitted into the second cutout portion 38b, while the second fitting portion 58a is fitted into the second cutout portion 38b. The fitting portion 58b is fitted into the second fitting recess 36b, and the second protruding portion 54b is fitted into the first cutout portion 38a. And the 1st fitting part 58a and the 2nd protrusion part 54b are contact | abutted from the circumferential direction one side with respect to the 1st contact part 40a, and the 2nd contact part 40b is made to contact | abut. On the other hand, the 1st protrusion part 54a and the 2nd fitting part 58b are contact | abutted from each circumferential direction one side. In the present embodiment, the covering rubber layer 31 is positioned on both sides in the circumferential direction of the fitting portion 58 by fitting the fitting portion 58 into the fitting recess 36. Accordingly, the fitting portion 58 is advantageously positioned on both sides in the circumferential direction by fitting the fitting portion 58 into the fitting recess 36.

  Further, in the present embodiment, as shown in FIG. 3, the covering rubber layer 31 constituting the side wall surface of the first support groove 32 a faces the inner side in the axial direction at the place where the fitting recess 36 is formed. And a slightly projecting seal portion 64 is provided. As shown in FIG. 4, the fitting portion 58 is fitted into the fitting recess 36, and the seal portion 64 is pressed against the fitting portion 58, so that the circumferential end portion of the orifice member 46 is pressed. The axially outer end surface and the side wall surface of the first support groove 32a are brought into fluid tight contact with each other.

  Further, the first passage formation portion 56a and the second passage formation portion 56b have their protruding tip portions in the axial direction overlapped with each other in the projection in the circumferential direction. And between the circumferential direction of the axial direction protrusion tip part of the 1st channel formation part 56a and the 2nd channel formation part 56b, elastic seal projection 33 projected and formed in the bottom of the 1st support groove 32a is located. The axially projecting tip portion of the first passage forming portion 56a and the axially projecting tip portion of the second passage forming portion 56b are pressed against the circumferential end surface of the elastic seal projection 33 from both sides in the circumferential direction. It is designed to be in close contact with the fluid.

  Further, the end surface on the outer side in the circumferential direction (right side in FIG. 4) of the first passage forming portion 56a is overlapped with the first elastic valve body 34a in the circumferential direction, and the second passage forming portion 56b. The end surface on the outer side in the circumferential direction (on the left side in FIG. 4) is overlapped with the second elastic valve body 34b in the circumferential direction. In the present embodiment, the first and second elastic valve bodies 34a and 34b are pressed against the first and second passage forming portions 56a and 56b in the circumferential direction. The overlapping surfaces of the first and second elastic valve bodies 34a, 34b on the first and second passage forming portions 56a, 56b are inclined slightly toward the passage forming portion 56 toward the outer peripheral side. The first and second elastic valve bodies 34a and 34b are advantageously brought into close contact with the first and second passage forming portions 56a and 56b.

  In addition, the outer tube fitting 14 is fitted and fixed to the integrally vulcanized molded product 28 in a state where the orifice member 46 is thus positioned in the circumferential direction and assembled to the integrally vulcanized molded product 28. The outer tube fitting 14 has a thin, large-diameter, generally cylindrical shape, and has a larger diameter than the large-diameter portion (both axial end portions) of the metal sleeve 20 after drawing. Further, in the present embodiment, the axial dimension of the outer cylindrical metal fitting 14 is substantially equal to the axial dimension of the metal sleeve 20. In addition, a thin seal rubber layer 66 is formed on the inner peripheral surface of the outer cylindrical metal member 14 over substantially the entire surface.

  The outer cylinder fitting 14 provided with such a seal rubber layer 66 is extrapolated with respect to the integrally vulcanized molded product 28 to which the orifice member 46 is assembled. Then, the outer cylinder fitting 14 is fitted and fixed to the integrally vulcanized molded product 28 by subjecting the outer cylinder fitting 14 to diameter reduction processing such as an eight-way drawing. The outer cylinder fitting 14 is in close contact with the metal sleeve 20 and the orifice member 46 via the seal rubber layer 66, and the overlapping surface between the outer cylinder fitting 14, the metal sleeve 20 and the orifice member 46 is fluid-tightly sealed. Has been. In particular, in the present embodiment, a plurality of seal protrusions protruding from the seal rubber layer 66 to the inner peripheral side are integrally formed at the overlapping portion of the outer cylinder fitting 14, the metal sleeve 20, and the orifice member 46. The space between the overlapping surfaces of the metal fitting 14, the metal sleeve 20, and the orifice member 46 is more advantageously sealed.

  In particular, in the present embodiment, a buffer recess 42 is formed between the fitting recess 36 and the notch 38 in the circumferential direction, and the buffer recess 42 absorbs stress acting on the orifice member 46 when the outer cylinder fitting 14 is reduced in diameter. It can be done.

  That is, when the diameter reduction processing is performed on the outer cylinder fitting 14, an external force is applied to the orifice member 46, and the circumferential end of the orifice member 46 may be displaced in the circumferential direction. In such a case, between the circumferential end portions of the first and second orifice forming members 48a and 48b indirectly contacted in the circumferential direction via the contact portion 40, the contact portion 40 is interposed. Thus, the stress is transmitted, and the positional deviation in the circumferential direction of one orifice forming member 48 may adversely affect the other orifice forming member 48. Here, by providing a buffer recess 42 in the circumferential intermediate portion of the contact portion 40 and substantially dividing the contact portion 40 in the circumferential direction, the first orifice forming member 48a and the second orifice forming member. The stress transmitted through the contact portion 40 can be absorbed between the circumferential ends of 48b. Therefore, it is possible to prevent displacement of the orifice member 46 as a whole, and it is also possible to prevent deformation and destruction of the orifice member 46 by making the contact portion 40 deformable in a buffering manner.

  In the present embodiment, the buffer recess 42 is formed so as to be biased in the circumferential direction toward the notch 38. Thereby, the part located in the circumferential direction of the notch part 38 and the buffer recessed part 42 in the contact part 40 is thin in the circumferential direction, and is relatively easily deformed elastically. Thereby, the stress absorption effect can be exhibited more advantageously.

  Under such an assembled state of the outer cylinder fitting 14, the openings of the first and second pocket portions 44a, 44b formed in the integrally vulcanized molded product 28 are covered with the outer cylinder fitting 14, and the fluid sealing region Is formed. In addition, the incompressible fluid is enclosed in the fluid enclosure region by, for example, performing the assembly of the outer cylinder fitting 14 to the integrally vulcanized molded product 28 in the incompressible fluid. As a result, a first fluid chamber 68a in which an incompressible fluid is sealed is formed using the first pocket portion 44a, and the second pocket portion 44b is used to form an interior. A second fluid chamber 68b in which an incompressible fluid is enclosed is formed.

  The incompressible fluid sealed in the first and second fluid chambers 68a and 68b is not particularly limited, but water, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof. A thing etc. are employ | adopted suitably. Furthermore, it is desirable to employ a low-viscosity fluid having a viscosity of 0.1 Pa · s or less in order to advantageously obtain an anti-vibration effect based on the fluid flow action described later. Further, in the present embodiment, both the first fluid chamber 68a and the second fluid chamber 68b are configured such that a part of the wall portion is constituted by the main rubber elastic body 16, and the main rubber elastic body 16 is in the state of vibration input. It is a pressure receiving chamber in which pressure fluctuation based on elastic deformation is generated.

  Further, by assembling the outer cylinder fitting 14 to the integrally vulcanized molded product 28, openings on the outer peripheral side of the first and second support grooves 32a and 32b provided between the pair of fluid chambers 68a and 68b in the circumferential direction. Is covered fluid-tightly by the outer tube fitting 14. Thus, a tunnel-like region extending between the circumferential directions of the first and second fluid chambers 68a and 68b with a predetermined length in the circumferential direction is formed using the first and second support grooves 32a and 32b. Has been. Note that, in the same manner as the fluid chamber 68, the incompressible fluid is also sealed in the above-described tunnel-shaped region formed using the first and second support grooves 32a and 32b.

  Further, an orifice member 46 is sandwiched and fixedly supported between the outer cylinder fitting 14 and the radially opposing surfaces of the bottom wall portions of the first and second support grooves 32a and 32b. Further, the outer peripheral surface of the orifice member 46 is pressed against the outer cylinder fitting 14 via the seal rubber layer 66, and the outer peripheral surface of the orifice member 46 and the inner peripheral surface of the outer cylinder fitting 14 are brought into close contact with each other. As a result, the circumferential concave groove 62 formed so as to open on the outer peripheral surface of the orifice member 46 is covered with the outer cylinder fitting 14, and a tunnel-like flow path extending in the circumferential direction with a predetermined length of slightly less than one round is formed. Has been. This flow path has one end communicating with the first fluid chamber 68a and the other end communicating with the second fluid chamber 68b, and the first fluid chamber 68a is communicated with the flow path. And an orifice passage 70 that communicates the second fluid chamber 68b with each other in the circumferential direction.

  Further, the outer peripheral surfaces of the pair of passage forming portions 56a and 56b formed integrally with the orifice member 46 are brought into close contact with the inner peripheral surface of the outer cylinder fitting 14 via the seal rubber layer 66, and the first The outer peripheral surface of the elastic seal projection 33 formed between the circumferential direction of the passage forming portion 56a and the second passage forming portion 56b is brought into pressure contact with the outer cylinder fitting 14. Thus, the first support groove 32 a is closed at the intermediate portion in the circumferential direction by the cooperation of the first and second passage forming portions 56 a and 56 b and the elastic seal protrusion 33.

  In addition, due to the diameter reduction of the outer cylinder fitting 14, the inner peripheral surfaces of the first and second orifice forming members 48a and 48b in the circumferential direction end with respect to the bottom surfaces of the first and second support grooves 32a and 32b. And pressed against the first and second support grooves 32 a and 32 b through the covering rubber layer 31.

  Here, a first communicating groove 72a as an inner groove is formed in the first passage forming portion 56a, and a second communicating groove 72b as an inner groove is formed in the second passage forming portion 56b. Is formed. The communication groove 72 is formed in the vicinity of the end of the passage forming portion 56 on the base end side (support arm portion 52 side), and opens to the inner peripheral surface of the passage forming portion 56 so as to be linear in the circumferential direction. It is formed to extend. Further, the circumferential end of the communication concave groove 72 is opened on the circumferential end surface of the passage forming portion 56.

  The first and second passage forming portions 56a and 56b in which the first and second communication concave grooves 72a and 72b are formed are formed on the bottom surface of the first support groove 32a by fitting and fixing the outer tube metal fitting 14. The inner peripheral surface of the first support groove 32a is brought into close contact with the bottom surface of the first support groove 32a through the covering rubber layer 31. As a result, the first and second communication concave grooves 72a and 72b formed in the first and second passage forming portions 56a and 56b are arranged such that the inner peripheral side opening is fluidized by the bottom surface of the first support groove 32a. Closely covered. And the 1st short circuit passage 74a which mutually connects the field of the peripheral direction both sides which sandwiched the 1st passage formation part 56a using the 1st communicating concave groove 72a is formed, and the 2nd communication A second short-circuit passage 74b is formed that communicates the regions on both sides in the circumferential direction sandwiching the second passage formation portion 56b with the use of the concave groove 72b.

  In the present embodiment, the first and second short-circuit passages 74a and 74b are formed independently of each other, and each has a tunnel-like shape communicating with the first fluid chamber 68a and the second fluid chamber 68b. It is a passage. Further, as apparent from the above description, the wall portion of the first short-circuit passage 74a is formed by the cooperation of the first passage-forming portion 56a and the first support groove 32a, and the second short-circuit passage is formed. The wall portion of the passage 74b is formed by the cooperation of the second passage formation portion 56b and the first support groove 32a.

  The first elastic valve element 34a is overlapped and brought into close contact with the end surface of the first passage forming portion 56a on the second fluid chamber 68b side. As a result, the opening on the second fluid chamber 68b side of the first short-circuit passage 74a is closed by the first elastic valve element 34a. On the other hand, the second elastic valve body 34b is overlapped and brought into close contact with the end surface of the second passage forming portion 56b on the first fluid chamber 68a side. Thereby, the opening of the second short circuit passage 74b on the first fluid chamber 68a side is closed by the second elastic valve body 34b. As described above, the tunnel-shaped region formed by covering the opening on the outer peripheral side of the first support groove 32a with the outer cylindrical metal member 14 is substantially closed in the non-input state of vibration. In the present embodiment, the elastic valve body 34 is pressed against the passage forming portion 56 of the orifice member 46 in the circumferential direction, and the opening of the short-circuit passage 74 is advantageously closed by the elastic valve body 34. It is supposed to be.

  When vibration is input to the vibration isolating bush 10 having the structure according to the present embodiment and a relative pressure fluctuation is induced between the first fluid chamber 68a and the second fluid chamber 68b, The sealed fluid is caused to flow through the orifice passage 70 based on the pressure difference between the first fluid chamber 68a and the second fluid chamber 68b. As a result, an anti-vibration effect based on a fluid action such as a resonance action of the fluid flowing through the orifice passage 70 is exhibited. The orifice passage 70 is configured to effectively exhibit a vibration isolation effect based on a fluid flow action against input vibration in a target frequency range by adjusting the passage length and the passage cross-sectional area. .

  During such normal vibration input, the first short-circuit passage 74a and the second short-circuit passage 74b are kept closed by the first elastic valve body 34a and the second elastic valve body 34b. Thereby, the relative pressure fluctuation of the first fluid chamber 68a and the second fluid chamber 68b can be effectively caused, and the amount of fluid flow through the orifice passage 70 can be advantageously ensured. Therefore, it is possible to effectively exhibit the vibration isolation effect based on the fluid flow action. In particular, in the present embodiment, the elastic valve element 34 is pressed against the passage forming portion 56 in the circumferential direction under a load non-input state, and the closed state of the short-circuit passage 74 is stabilized even during normal vibration input. Is to be maintained.

  On the other hand, when a large pressure fluctuation occurs between the first fluid chamber 68a and the second fluid chamber 68b due to the input of a shocking large load, the first elastic valve body 34a and the second elastic valve body. 34b is sucked to the negative pressure side based on the pressure difference between the first and second fluid chambers 68a and 68b located on both sides in the circumferential direction. As a result, one of the first elastic valve body 34a and the second elastic valve body 34b is pressed against one of the first and second passage forming portions 56a and 56b by the pressure difference, and the first Either one of the elastic valve body 34a and the second elastic valve body 34b is elastically deformed so as to be separated from the other one of the first and second passage forming portions 56a and 56b in the circumferential direction.

  Here, when the elastic valve body 34 is elastically deformed and separated from the passage forming portion 56, the first fluid chamber 68 a and the second fluid chamber 68 b are communicated through the short-circuit passage 74 formed in the passage forming portion 56. It is done. As a result, the sealed fluid flows between the chambers 68a and 68b through the short-circuit passage 74, and the relative pressure difference between the first fluid chamber 68a and the second fluid chamber 68b is eliminated as quickly as possible. It is like that.

  Specifically, for example, when the pressure in the first fluid chamber 68a becomes lower than the pressure in the second fluid chamber 68b, the first elastic valve body 34a is moved to the first and second fluid chambers. Based on the relative pressure difference between 68a and 68b, the first short circuit passage 74a is maintained in the closed state by being pressed against the first passage forming portion 56a in the circumferential direction. On the other hand, based on the relative pressure difference between the first and second elastic valve bodies 34a and 34b, the second elastic valve body 34b is elastically deformed and separated from the second passage forming portion 56b in the circumferential direction. I'm damned. As a result, the opening on the second fluid chamber 68b side of the second short-circuit passage 74b closed by the second elastic valve body 34b is in a communication state, and the first fluid chamber 68a and the second fluid are communicated. The chambers 68b are communicated with each other through the second short-circuit passage 74b. The fluid is caused to flow between the first fluid chamber 68a and the second fluid chamber 68b through the second short-circuit passage 74b, so that the relative relationship between the first fluid chamber 68a and the second fluid chamber 68b is increased. The pressure difference is eliminated.

  Thus, the first and second fluid chambers 68a and 68b are short-circuited through the short-circuit passage 74, and the relative pressure difference between the two chambers 68a and 68b is eliminated. Generation of excessive negative pressure in the fluid chamber 68 can be avoided, and gas dissolved in the sealed fluid can be prevented from being separated to generate bubbles. As a result, the water hammer pressure generated when the bubbles again melt into the sealed fluid can be prevented, and the generation of abnormal noise and vibration that can be attributed to the propagation of the water hammer pressure can be effectively reduced or avoided. .

  When the first fluid chamber 68a is on the negative pressure side due to vibration input, the second short circuit passage 74b is in a communicating state, while when the second fluid chamber 68b is on the negative pressure side, The first short-circuit passage 74a is in a communication state. In short, at the time of input of large amplitude vibration, one of the first short-circuit passage 74a and the second short-circuit passage 74b is selectively brought into a communication state, and the first fluid chamber 68a and the second fluid chamber 68b are connected. The circumferential direction is short-circuited. Therefore, even when a negative pressure is generated in any of the pair of fluid chambers 68a and 68b, the negative pressure can be quickly eliminated, and the generation of abnormal noise and vibration can be effectively reduced or avoided.

  In addition, since the short-circuit passage 74 is formed by using the passage formation portion 56 formed integrally with the orifice member 46, the anti-vibration bushing 10 having the excellent effects as described above is formed in the short-circuit passage 74. It can be realized with a small number of parts and a simple structure without adding special parts. Furthermore, it can be manufactured easily by avoiding an increase in the number of parts.

  Moreover, in this embodiment, the orifice member 46 is comprised by combining the 1st orifice formation member 48a and the 2nd orifice formation member 48b which were made into the circumferential direction length of a little less than half circumference, respectively in the circumferential direction. Therefore, the assembly of the orifice member 46 to the integrally vulcanized molded product 28 can be easily realized. In addition, since the first orifice forming member 48a and the second orifice forming member 48b have the same shape, the types of necessary parts can be reduced.

  As mentioned above, although one Embodiment of this invention was described, this is an illustration to the last, Comprising: This invention is not interpreted restrictively at all by the specific description in this Embodiment.

  For example, the short-circuit passage 74 shown in the embodiment is formed so as to extend linearly in the circumferential direction. However, the short-circuit path may be curved and extend in the axial direction, or may extend so as to meander. In the above-described embodiment, the short-circuit passage 74 is formed so as to open on both end surfaces in the circumferential direction of the passage formation portion 56, but the short-circuit passage is not necessarily formed so as to open on the end surface in the circumferential direction of the passage formation portion. It may be sufficient if it is formed so as to communicate between the fluid chambers.

  In the embodiment, the orifice member 46 is configured by combining the first and second orifice forming members 48a and 48b. However, the orifice member does not necessarily have to be configured by combining a plurality of members, and may be formed as one member that is not divided in the circumferential direction on the second circumferential groove. When the orifice member is formed as a single C-shaped member in this way, the assembly into the integrally vulcanized molded product is advantageously realized by making the orifice member elastically deformable. I can do it.

  Further, the structure of the orifice member is not particularly limited, and the structure of the end portion in the circumferential direction of the orifice member that is fitted in the first circumferential groove is interpreted in a limited manner by the specific description in the embodiment. Is not to be done.

  Moreover, in the said embodiment, although the orifice member 46 formed using the hard synthetic resin as a material is illustrated, the formation material of an orifice member is not specifically limited, For example, metals, such as iron and aluminum alloy It may be formed of a material or the like. In order to keep the tuning of the orifice passage at the set frequency, it is desirable that the member is a hard member, but a certain degree of deformation may be allowed.

  In the above-described embodiment, both the first fluid chamber 68a and the second fluid chamber 68b are pressure receiving chambers in which fluid pressure fluctuations are generated based on elastic deformation of the main rubber elastic body 16 when vibration is input. Thus, fluid flow is caused by relative pressure fluctuations. However, according to the present invention, for example, one of the fluid chambers is a pressure receiving chamber in which a fluid pressure fluctuation is generated based on elastic deformation of the main rubber elastic body when vibration is input, and the first and second fluids in the above embodiment are used. An equilibrium chamber that has substantially the same structure as the chamber, and the other fluid chamber is made of a flexible membrane in which a part of the wall portion can be easily deformed to allow a change in volume. The present invention can also be applied to a fluid-filled cylindrical vibration isolator having a structure as described above.

  In the above embodiment, the first and second short-circuit passages 74a and 74b that can communicate with each other independently are formed, but two short-circuit passages are not necessarily formed independently. For example, in the fluid-filled cylindrical vibration isolator having a structure including the pressure receiving chamber and the equilibrium chamber as described above, one short-circuit path that is in communication when negative pressure is generated in the pressure receiving chamber. It may be a structure with only. Needless to say, the structure may include three or more short-circuit passages.

  Further, the present invention is suitably applied to various vibration isolators for automobiles such as automobile suspension bushes, engine mounts, and body mounts. Furthermore, the present invention can also be applied to various types of vibration isolators used other than automobiles.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is a longitudinal cross-sectional view which shows the anti-vibration bush as one Embodiment of this invention, Comprising: The II sectional view taken on the line in FIG. The II-II sectional view taken on the line of FIG. 1 of the anti-vibration bush shown by FIG. The front view which shows the diameter reduction process of the integral vulcanization molded product which comprises the vibration proof bush shown by FIG. The front view which shows the state which assembled | attached the orifice member to the integral vulcanization molded product after the diameter reduction process shown by FIG. Explanatory drawing which shows the integral vulcanization molded product which assembled | attached the orifice member shown by FIG. The front view which shows the orifice formation member which comprises the orifice member shown by FIG. The side view which shows the orifice formation member shown by FIG. The rear view which shows the orifice formation member shown by FIG. The bottom view which shows the orifice formation member shown by FIG.

Explanation of symbols

10: Anti-vibration bushing, 12: Inner cylinder fitting, 14: Outer cylinder fitting, 16: Rubber elastic body of main body, 20: Metal sleeve, 24: Open window, 26: Circumferential groove, 28: Integrated vulcanization molded product, 32: Support groove, 33: elastic seal protrusion, 34: elastic valve body, 40: contact portion, 42: buffer recess, 44: pocket portion, 46: orifice member, 48: orifice forming member, 56: passage forming portion, 68: Fluid chamber, 70: Orifice passage, 72: Communication groove, 74: Short-circuit passage

Claims (7)

A first vulcanization molded product comprising an integral vulcanized molded product in which a shaft member and an intermediate sleeve arranged apart from the outer periphery thereof are elastically connected by a main rubber elastic body, and is formed at an axially intermediate portion of the intermediate sleeve The first and second pocket portions that open to the outer peripheral surface through the second window portion are provided in the main rubber elastic body, and the outer cylinder member is fitted to the integral vulcanized molded product. The first and second fluid chambers in which the incompressible fluid is sealed are formed by fluidly covering the openings of the first and second pocket portions by being fixedly attached, and the intermediate sleeve The first and second support grooves extending in the circumferential direction between the first and second fluid chambers are formed in the intermediate portion in the axial direction of the first and second fluid chambers. An orifice member extending in the direction is fitted, and the orifice member is interposed between the intermediate sleeve and the outer cylinder member. A fluid-filled type in which a concave groove formed on the outer peripheral surface of the orifice member is covered with the outer cylinder member so as to form an orifice passage communicating the first and second fluid chambers with each other. In the cylindrical vibration isolator,
A portion of the orifice member that is fitted in the first support groove is divided in the circumferential direction, and at least one of both ends divided in the circumferential direction of the orifice member is an inner groove that opens to the inner circumferential surface. And the inner groove is covered with the bottom surface of the first support groove, thereby forming a short-circuit passage that connects the first fluid chamber and the second fluid chamber to each other. The first support groove is provided with a valve body rubber, and the valve body rubber is overlapped with a circumferential end surface of the orifice member where the short-circuit path is opened, and one opening of the short-circuit path is A fluid-filled cylindrical vibration isolator characterized by being closed by valve rubber.   A portion of the orifice member that is fitted into the first support groove is divided in the circumferential direction, and inner groove grooves that open to the inner circumferential surface are formed at both ends of the orifice member that are divided in the circumferential direction. And the first and second short-circuit passages connecting the first fluid chamber and the second fluid chamber are independent from each other by covering the inner groove with the bottom surface of the first support groove. On the other hand, the first support groove is provided with first and second valve body rubbers, and the first valve body rubber is used to open the first short circuit passage. The second valve body rubber is overlaid on the circumferential end surface of the orifice member where the second short-circuit passage is opened, and the second valve body rubber is overlaid on the circumferential end surface of the member. An opening on the fluid chamber side is closed with the first valve body rubber, and the second valve body rubber絡通 circuit fluid-filled cylindrical vibration damping device according to claim 1 in which the opening of the first fluid chamber side is closed by said second valve body rubber.   The first support groove is provided with an elastic seal protrusion protruding from the bottom surface, and the elastic seal protrusion is sandwiched between both end portions of the orifice member divided in the circumferential direction, and the first support groove The fluid-filled cylindrical vibration isolator according to claim 1 or 2, wherein the fluid-filled cylindrical vibration isolator is sandwiched between a bottom surface and the outer cylinder member so that both ends of the orifice member are fluid-tightly sealed.   The fluid according to any one of claims 1 to 3, wherein a contact portion that protrudes into the first support groove is provided on a side wall portion of a circumferential intermediate portion of the first support groove. Enclosed cylindrical vibration isolator.   The fluid-filled cylindrical vibration isolator according to claim 4, wherein a buffer recess that opens toward the inside of the first support groove is formed at a circumferential intermediate portion of the contact portion.   6. The fluid-filled cylindrical proof according to claim 1, wherein the valve body rubber is overlaid so as to come into pressure contact with a circumferential end surface of the orifice member where the short-circuit passage of the orifice member opens. Shaker.   The said orifice member is comprised by a pair of orifice formation member, The circumferential direction edge part of these pair of orifice formation members is each fitted in said 1st support groove | channel and said 2nd support groove | channel. The fluid-filled cylindrical vibration isolator according to claim 6.