JP2015068356A - Fluid sealed type cylindrical vibration-proofing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid sealed type cylindrical vibration-proofing device having a new structure capable of preventing vibration-proofing performance from being reduced due to short-circuit while a passage length of an orifice passage is efficiently assured.SOLUTION: Both ends of an orifice member 36 are fitted to each of circumferential ends of a fitting groove 22, an intermediate portion in a circumferential direction within the fitting groove 22 is provided with a bottom wall connecting rubber 54 projected from a groove bottom surface toward an outer circumferential side and the bottom wall connecting rubber 54 is held between both ends of a circumferential direction of the bottom wall part of the orifice member 36. In turn, the intermediate portion in a groove width direction of the bottom wall connecting rubber 54 is formed with a division wall connecting rubber 56 protruded at the outer circumferential side and abutted against the inner circumferential surface of an outer cylindrical member 14. A division wall part 48 between each of a plurality of communication grooves 44, 46 opened to each of both end portions in a circumferential direction of the orifice member 36 is pushed against the division wall connecting rubber 56 from both sides in a circumferential direction and the division wall connecting rubber 56 is compressed in a circumferential direction without being buckled.

Description

  The present invention relates to a fluid-filled cylindrical vibration isolator used for a suspension bush of an automobile, an engine mount, a body mount, a subframe mount, a differential mount, and the like.

  2. Description of the Related Art Conventionally, a cylindrical vibration isolator is known as a type of anti-vibration support body or anti-vibration coupling body interposed between members constituting a vibration transmission system. Furthermore, a fluid-filled cylindrical vibration damping device that utilizes a vibration damping effect based on the flow action of the fluid sealed inside has also been proposed. In this fluid-filled cylindrical vibration isolator, for example, as described in Japanese Patent No. 2583212 (Patent Document 1), an inner shaft member and an outer cylindrical member are elastically connected by a main rubber elastic body. A first fluid chamber in which relative pressure fluctuations are generated when vibration is input by covering a pair of pocket portions opened on the outer peripheral surface of the main rubber elastic body with an outer cylinder member and enclosing an incompressible fluid And a second fluid chamber is formed. Furthermore, an orifice member that extends in the circumferential direction across the first fluid chamber and the second fluid chamber is attached, and the communication groove that opens to the outer peripheral surface of the orifice member is covered with the outer cylinder member. An orifice passage is formed to communicate the one fluid chamber and the second fluid chamber with each other.

  Incidentally, the orifice member extending across the first fluid chamber and the second fluid chamber has a pair of halves as shown in Patent Document 1 in order to facilitate mounting to the main rubber elastic body. May be configured in combination. Further, in Patent Document 1, in a fluid-filled cylindrical vibration isolator having a predetermined outer diameter, in order to obtain a large passage length of the orifice passage, a communication groove having a length exceeding one turn in the circumferential direction is spiral. Is formed.

  However, as shown in FIG. 1 (c) of Patent Document 1, since the circumferential ends of the halves made rigid are in direct contact with each other in the circumferential direction, A gap is easily formed between the circumferential ends of the halves. In particular, since two communication grooves are provided in parallel in the axial direction at the circumferential end portion of the half body, a gap is generated between the circumferential end portions of the half body in which the two communication grooves are formed. When the two communication grooves are short-circuited through the gap, the short-circuited fluid flow hinders fluid flow in the passage length direction of the orifice passage, and the target vibration-proof performance may not be effectively exhibited.

Japanese Patent No. 2583212

  The present invention has been made in the background of the above-mentioned circumstances, and its solution is to prevent the deterioration of the vibration proof performance due to a short circuit while efficiently securing the length of the orifice passage. An object of the present invention is to provide a fluid-filled cylindrical vibration isolator having a novel structure capable of effectively obtaining vibration performance.

  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.

  That is, according to the first aspect of the present invention, the inner shaft member and the outer cylinder member are elastically connected by the main rubber elastic body, and a pair of pocket portions that open to the outer peripheral surface of the main rubber elastic body are provided in the outer cylinder. By covering with a member, a first fluid chamber and a second fluid chamber are formed in which an incompressible fluid is enclosed and a relative pressure fluctuation occurs when vibration is input. An orifice member extending in the circumferential direction across the second fluid chamber is assembled between the main rubber elastic body and the outer cylinder member, and the orifice member opens to the outer peripheral surface to form a circumferential spiral shape. A communication groove extending in the direction is formed, and an outer peripheral opening of the communication groove is covered with the outer cylindrical member, thereby forming an orifice passage that allows the first fluid chamber and the second fluid chamber to communicate with each other. Fluid filled cylindrical vibration isolator A fitting groove extending in the circumferential direction is formed between the first fluid chamber and the second fluid chamber in the circumferential direction, and both end portions of the orifice member that face each other in the circumferential direction are A bottom wall connecting rubber that is fitted to one end in the circumferential direction of the fitting groove and that protrudes from the groove bottom surface to the outer circumferential side is provided at a circumferential intermediate portion in the fitting groove. While the connecting rubber is sandwiched between both circumferential ends of the bottom wall portion of the orifice member, the bottom wall connecting rubber projects in the middle in the groove width direction to the outer peripheral side to the inner peripheral surface of the outer cylindrical member. A partition connecting rubber to be in contact is formed, and partition portions between the plurality of communication grooves respectively opening at both ends in the circumferential direction of the orifice member are pressed against the partition connecting rubber from both sides in the circumferential direction, The partition rubber is compressed in the circumferential direction without buckling It is possible to, characterized that.

  According to the fluid-filled cylindrical vibration isolator having the structure according to the first aspect as described above, both ends in the circumferential direction of the orifice member fitted into the fitting groove portion are in contact with the bottom wall connecting rubber and the partition wall connecting rubber. By being pressed from both sides in the circumferential direction, fluid leakage is prevented between both ends in the circumferential direction of the orifice member. Therefore, at both ends in the circumferential direction of the orifice member where a plurality of communication grooves are opened, a short circuit between the communication grooves and the occurrence of turbulent flow in the orifice passage are avoided, thereby preventing the flow based on fluid flow. The vibration effect is exhibited efficiently.

  Furthermore, the partition wall connecting rubber protruding to the outer peripheral side is compressed in the circumferential direction without buckling and deforming into strain. Therefore, the partition wall connecting rubber and the orifice member and the outer cylinder member are maintained in a fluid-tight sealed state, and fluid flow through the orifice passage is efficiently generated, so that the intended protection is achieved. The vibration effect can be obtained advantageously.

  According to a second aspect of the present invention, in the fluid-filled cylindrical vibration damping device described in the first aspect, the bottom surface of the communication groove of the orifice member has the same radial position as the outer peripheral surface of the bottom wall connecting rubber. It is the one that is positioned in.

  According to the second aspect, it is possible to reduce the size of the step generated at the connecting portion between the bottom wall portion of the orifice member and the bottom wall connecting rubber, so that the flow resistance of the orifice passage can be reduced, and the fluid The vibration isolation effect based on the fluid action can be obtained more advantageously.

  According to a third aspect of the present invention, in the fluid-filled cylindrical vibration isolator described in the first or second aspect, the circumferential end of the partition wall portion of the orifice member is gradually increased outward in the circumferential direction. It is thick in the axial direction.

  According to the 3rd aspect, it becomes possible to employ | adopt a thick partition connection rubber | gum in an axial direction, without producing a big level | step difference in a boundary with a partition part. This keeps the shape without buckling even if the bulkhead connecting rubber is compressed with greater force in the circumferential direction, avoiding the short circuit of the orifice passage more effectively and preventing the flow resistance of the orifice passage from increasing. As a result, the intended vibration isolation effect can be obtained advantageously. In addition, since the partition wall is gradually thickened in the circumferential direction, no step is formed in the partition wall, and the flow resistance of the fluid in the orifice passage is suppressed.

  According to a fourth aspect of the present invention, in the fluid-filled cylindrical vibration isolator described in any one of the first to third aspects, each of the plurality of the openings opening at both circumferential ends of the orifice member is provided. A shaft end wall portion on the outer side in the axial direction of the communication groove is provided in a circumferentially inner side than the partition wall portion, and a groove inner surface of the communication groove formed by the shaft end wall portion faces the outer side in the circumferential direction. A taper surface that is gradually inclined outward in the axial direction, and a surface of the covering rubber that covers the groove inner surface on the axially outer side of the fitting groove portion is gradually inclined inward in the circumferential direction. These tapered surfaces are connected in the circumferential direction and continuously spread.

  According to the fourth aspect, by connecting the taper surface of the shaft end wall portion and the taper surface of the covering rubber so as to continuously spread, the orifice passage between the circumferential end portions of the orifice member and between the circumferential directions thereof. Is spread outward in the axial direction. As a result, for example, even if the circumferential end of the partition wall and the partition connecting rubber are thick in the axial direction, it is possible to prevent the passage cross-sectional area of the orifice passage from becoming small, and to achieve the desired prevention at a predetermined frequency. The vibration effect can be obtained effectively.

  In addition, by providing a tapered surface, a shaft end wall portion that becomes gradually thinner in the axial direction toward the outer side in the circumferential direction is provided in the circumferential direction inner side than the partition wall portion, and the tapered surface of the shaft end wall portion is covered. By being connected to the tapered surface of the rubber, a large passage cross-sectional area of the orifice passage can be secured without making the circumferential end of the shaft end wall portion extremely thin. As a result, it is possible to avoid damage to the covering rubber and injury of the manufacturing worker due to contact with the circumferential end of the shaft end wall portion, and it is possible to advantageously obtain a vibration isolation effect based on the fluid flow action.

  According to a fifth aspect of the present invention, in the fluid-filled cylindrical vibration isolator described in any one of the first to fourth aspects, a seal lip projecting outward from the outer peripheral surface of the partition wall connecting rubber. Is formed continuously over the entire length in the circumferential direction.

  According to the fifth aspect, since the seal lip is pressed against the inner peripheral surface of the outer cylinder member, the space between the partition wall connecting rubber and the outer cylinder member is fluid-tightly sealed with higher sealing properties. A plurality of communication grooves can be advantageously prevented from short-circuiting each other between the partition wall connecting rubber and the outer cylinder member, and a vibration isolation effect due to fluid flow can be obtained efficiently.

  According to a sixth aspect of the present invention, in the fluid-filled cylindrical vibration isolator described in any one of the first to fifth aspects, a set of halves in which the orifice member is divided in the circumferential direction. One of the halves extends across the first fluid chamber in the circumferential direction, and the other half halves extends across the second fluid chamber in the circumferential direction. It is what.

  According to the sixth aspect, since the orifice member is divided in the circumferential direction, the orifice member can be easily assembled between the main rubber elastic body and the outer cylinder member. In addition, since the orifice member is divided into a set of halves, the number of divisions of the orifice member is minimized while ensuring easy assembly of the orifice member to the main rubber elastic body and the outer cylinder member. With a simple structure, a fluid short circuit is advantageously avoided.

  According to a seventh aspect of the present invention, in the fluid-filled cylindrical vibration damping device described in any one of the first to sixth aspects, an intermediate sleeve is extrapolated to the inner shaft member. The shaft member and the intermediate sleeve are elastically connected by the main rubber elastic body, and the outer cylindrical member is externally fitted to the intermediate sleeve, while the pair of pocket portions formed in the main rubber elastic body It opens to an outer peripheral surface through a pair of window part formed in this intermediate sleeve, and the said fitting groove part is formed between the circumferential directions of this pair of window part in this intermediate sleeve.

  According to the seventh aspect, since the outer peripheral surface of the main rubber elastic body is restrained by the hard intermediate sleeve and the stability of the shape is improved, the first fluid chamber, the second fluid chamber, the orifice passage, etc. In the fluid sealing region, fluid leakage is more reliably prevented. Moreover, since the fitting groove for supporting the orifice member is formed by the intermediate sleeve, the orifice member is stably supported, and a short circuit of the orifice passage can be advantageously avoided.

  According to the present invention, both ends in the circumferential direction of the orifice member fitted in the fitting groove are pressed against the bottom wall connecting rubber from both sides in the circumferential direction, and the partition is surrounded by the partition connecting rubber. It is pressed from both directions. This prevents a short circuit of the plurality of communication grooves between the circumferential ends of the orifice member, and the fluid flow in the passage length direction of the orifice passage is efficiently generated. Can be advantageously obtained. In addition, since the partition wall connecting rubber with which the partition wall portion of the orifice member is pressed from both sides in the circumferential direction is compressed in the circumferential direction without buckling, the contact surface between the partition wall connecting rubber and the partition wall portion and the outer cylinder member A gap is prevented from being formed between them, and a reduction in the vibration isolation performance due to a short circuit of the plurality of communication grooves is avoided.

It is sectional drawing which shows the suspension bush as one Embodiment of this invention, Comprising: The figure corresponded in the II cross section in FIG. II-II sectional drawing of FIG. The right view of the integral vulcanization molded product which comprises the suspension bush shown in FIG. IV-IV sectional drawing of FIG. The top view of the orifice member which comprises the suspension bush shown in FIG. The front view of the orifice member shown in FIG. FIG. 7 is a rear view of the orifice member shown in FIG. 6. The left view which attached the orifice member shown in FIG. 5 to the integral vulcanization molded product shown in FIG. The right view which attached the orifice member shown in FIG. 5 to the integral vulcanization molded product shown in FIG. The figure which expands and shows the principal part 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 cylindrical vibration isolator 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 following description, the axial direction refers to the left-right direction in FIG. 2 that is the central axial direction of the inner shaft member 12 and the outer cylinder member 14.

  More specifically, the inner shaft member 12 has a thick and small-diameter, generally cylindrical shape, and is a highly rigid member formed of iron, aluminum alloy, or the like. The inner shaft member 12 is attached to the suspension arm side by inserting a rod member fixed to a suspension arm (not shown) through the center hole thereof.

  An intermediate sleeve 18 is externally inserted into the inner shaft member 12. The intermediate sleeve 18 is a highly rigid member formed of the same material as the inner shaft member 12 and has a thin cylindrical shape with a large diameter.

  Further, the intermediate sleeve 18 is formed with a pair of windows 20 and 20. The window portion 20 penetrates the intermediate portion in the axial direction of the intermediate sleeve 18 in the radial direction, and a pair extending in a length less than a half circumference in the circumferential direction is in one radial direction (up and down direction in FIG. 1). It is provided at an opposing position.

  Furthermore, the intermediate sleeve 18 is formed with a pair of fitting groove portions 22, 22. The fitting groove portion 22 is a concave groove that extends in the circumferential direction while opening to the outer peripheral surface at the intermediate portion in the axial direction of the intermediate sleeve 18, and is provided between the pair of window portions 20, 20 in the circumferential direction. Is communicated with one of the pair of windows 20.

  The inner shaft member 12 and the intermediate sleeve 18 are connected by a main rubber elastic body 16. The main rubber elastic body 16 has a thick, substantially cylindrical shape, and its inner peripheral surface is vulcanized and bonded to the inner shaft member 12 and its outer peripheral surface is vulcanized and bonded to the intermediate sleeve 18. As shown in FIGS. 3 and 4, the main rubber elastic body 16 of the present embodiment is formed as an integrally vulcanized molded product 23 including an inner shaft member 12 and an intermediate sleeve 18. The groove inner surface of the fitting groove portion 22 of the intermediate sleeve 18 is covered with a covering rubber 24 formed integrally with the main rubber elastic body 16. Further, the covering rubber 24 that covers the groove bottom surface of the fitting groove 22 is formed with a sealing protrusion 25 that protrudes toward the outer periphery and extends in the groove width direction of the fitting groove 22.

  Furthermore, a pair of pocket portions 26 and 26 are formed in the main rubber elastic body 16. The pocket portion 26 is a recess that opens to the outer peripheral surface in the axially intermediate portion of the main rubber elastic body 16, and a pair of pairs extending in a length less than a half circumference in the circumferential direction is opposed to each other in one radial direction. Is provided. The pair of pocket portions 26, 26 are open to the outer peripheral surface of the integrally vulcanized molded product 23 through one of the pair of window portions 20, 20 of the intermediate sleeve 18.

  Furthermore, a stopper rubber 28 protrudes from each bottom surface of the pair of pocket portions 26 and 26. The stopper rubber 28 is formed integrally with the main rubber elastic body 16 and protrudes from the outer peripheral surface of the inner shaft member 12 toward the outer periphery in one radial direction.

  The outer cylinder member 14 is attached to the integrally vulcanized molded product 23 of the main rubber elastic body 16. The outer cylinder member 14 is a highly rigid member similar to the inner shaft member 12 and the intermediate sleeve 18 and has a thin cylindrical shape with a large diameter. Further, the inner peripheral surface of the outer cylinder member 14 is fixed with a seal rubber layer 30 having a thin and large diameter substantially cylindrical shape, and the seal rubber layer 30 covers almost the entire surface.

  The outer cylinder member 14 is externally fitted to the intermediate sleeve 18 by being extrapolated to the intermediate sleeve 18 and subjected to diameter reduction processing such as an eight-way drawing. Further, the seal rubber layer 30 that covers the inner peripheral surface of the outer cylindrical member 14 is pressed against the outer peripheral surface of the intermediate sleeve 18 and is compressed between the intermediate sleeve 18 and the outer cylindrical member 14, whereby the intermediate sleeve is formed. A space between the overlapping surfaces of the outer cylinder member 18 and the outer cylinder member 14 is hermetically sealed.

  By attaching the outer cylinder member 14 in this manner, the pair of window portions 20 and 20 and the pair of pocket portions 26 and 26 of the intermediate sleeve 18 are covered with the outer cylinder member 14 in a fluid-tight manner. Accordingly, each of the first fluid chamber 32 and the second fluid chamber 34 is formed on both sides in the radial direction across the inner shaft member 12 by the pair of pocket portions 26, 26. An incompressible fluid is sealed in the chamber 32 and the second fluid chamber 34. In addition, by attaching the outer cylinder member 14 to the integrally vulcanized molded product 23 in a water tank filled with an incompressible fluid, the incompressible fluid is supplied to the first fluid chamber 32 and the second fluid chamber 34. Can be easily encapsulated. Further, the pair of fitting groove portions 22 and 22 are formed between the first fluid chamber 32 and the second fluid chamber 34 in the circumferential direction.

  The incompressible fluid sealed in the first fluid chamber 32 and the second fluid chamber 34 is not particularly limited. For example, water, ethylene glycol, alkylene glycol, polyalkylene glycol, silicone oil, or A mixed solution thereof is preferably used. Furthermore, in order to efficiently obtain a vibration isolation effect based on the fluid flow action described later, it is desirable that the sealed fluid is a low viscosity fluid of 0.1 Pa · s or less.

  As shown in FIGS. 1 and 2, an orifice member 36 is attached between the integrally vulcanized molded product 23 of the main rubber elastic body 16 and the outer cylinder member 14. The orifice member 36 has a substantially cylindrical shape as a whole, and is configured by combining a pair of halves 38, 38 in the circumferential direction.

  More specifically, as shown in FIGS. 5 to 7, the halved body 38 has a substantially semi-cylindrical shape, and is a hard member formed of metal, synthetic resin, or the like. Furthermore, a stopper receiving portion 40 that protrudes toward the inner peripheral side at the intermediate portion in the axial direction is formed in the intermediate portion in the peripheral direction of the half body 38. The stopper receiving portion 40 has an inner peripheral surface corresponding to the protruding front end surface of the stopper rubber 28, and the surface is covered with a buffer rubber layer 42. Furthermore, a projecting portion 43 that projects outward in the axial direction is integrally formed at the circumferential intermediate portion of the half body 38. The circumferential end surface of the projecting portion 43 extends in one radial direction (up and down in FIG. 6), and the circumferential end portion of the projecting portion 43 has a shape that gradually becomes narrower as it goes to the inner circumference as viewed in the axial direction. Have.

  Further, the halved body 38 is formed with a first communication groove 44 and a second communication groove 46 on the outer peripheral surface. The first communication groove 44 and the second communication groove 46 extend in the circumferential direction while opening on the outer peripheral surface, and are provided in parallel in the axial direction. In addition, both end portions in the circumferential direction of the first communication groove 44 are open to one end surface in the circumferential direction of the half body 38, while one end portion in the circumferential direction of the second communication groove 46 is in the half body 38. The other end in the circumferential direction of the second communication groove 46 is open in the other end surface in the circumferential direction of the half body 38. In short, only the first communication groove 44 is opened on one end surface in the circumferential direction of the half body 38, and two communication grooves 44 and 46 are opened on the other end surface in the circumferential direction. A partition wall 48 extending continuously in the circumferential direction is formed between the first communication groove 44 and the second communication groove 46, and the first and second communication grooves 44 and 46 have a full length. They are separated from each other by partition walls 48.

  As shown in FIGS. 8 and 9, a set of the halves 38 having such a structure is attached to the integral vulcanization molded product 23 of the main rubber elastic body 16. That is, the pair of halves 38, 38 are attached to the integrally vulcanized molded product 23 from both sides in the radial direction so as to face each other in an inverted state. As shown in FIGS. 1 and 2, one half 38 is disposed across the first fluid chamber 32 in the circumferential direction, and the other half 38 passes through the second fluid chamber 34. It is disposed across the circumferential direction.

  Further, the pair of halves 38, 38 are fitted to the respective ones of the pair of fitting grooves 22, 22 at the circumferential ends. That is, as shown in FIG. 8, one end in the circumferential direction of the halves 38, 38 in which only the first communication groove 44 opens is fitted into one fitting groove 22, and directly in the circumferential direction. As shown in FIG. 9, the other end in the circumferential direction of the halves 38 and 38 in which both the first and second communication grooves 44 and 46 are open is the other fitting groove. 22 is fitted to one end of each circumferential direction.

  In addition, since the groove | channel inner surface of a pair of fitting groove part 22 and 22 is covered with the covering rubber 24, the circumferential direction edge part of the half split body 38 is fitted with the fitting groove part 22 and 22 fluid-tightly. Yes. In the present embodiment, the sealing protrusion 25 formed on the covering rubber 24 covering the groove bottom surface of the fitting groove 22 is pressed against the circumferential end of the half 38 to fit the half 38. The space between the groove bottom surface of the groove portion 22 is more advantageously sealed. Further, the circumferential end of the protruding portion 43 of the halved body 38 has an inner peripheral end pressed against the covering rubber 24 in the circumferential direction, and the space between the protruding portion 43 and the covering rubber 24 is sealed in a fluid-tight manner. ing. In particular, since the circumferential end of the protrusion 43 becomes narrower toward the inner periphery, the contact pressure against the covering rubber 24 is increased, and the sealing performance is advantageously obtained.

  The pair of halves 38, 38 are attached to the integrally vulcanized molded product 23, and one end in the circumferential direction is substantially connected to each other. As a result, the generally C-shaped orifice member 36 is configured as viewed in the axial direction. Then, both end portions in the circumferential direction of the orifice members 36 that are butted against each other in the circumferential direction are fitted into one end portion in the circumferential direction of the other fitting groove portion 22.

  Further, the first communication grooves 44, 44 of the pair of halves 38, 38 are communicated with each other at the ends fitted into the one fitting groove 22, and the first halves 38, One communication groove 44 and the second communication groove 46 of the other half body 38 and the second communication groove 46 of one half body 38 and the first communication groove 44 of the other half body 38 are the other. The end portions fitted to the fitting groove portions 22 communicate with each other, and a spiral circumferential groove 50 is formed extending in the circumferential direction with a predetermined length of less than two turns. In addition, the spiral shape mentioned here should just have a part extended in the circumferential direction longer than one round, and extending in the circumferential direction along with the axial cross section. Furthermore, the lead angle of the circumferential groove 50 does not need to be constant, and it is not necessary for the circumferential grooves 50 to be parallel to each other in the circumferential direction along the axial section.

  Here, a connection rubber 52 is formed between both circumferential ends of the orifice member 36 fitted in the other fitting groove 22. The connection rubber 52 is formed at a middle portion in the circumferential direction in the fitting groove portion 22 and integrally includes a bottom wall connection rubber 54 and a partition wall connection rubber 56.

  More specifically, as shown in FIGS. 3, 4, and 10, the bottom wall connecting rubber 54 is formed in the middle portion in the circumferential direction in the other fitting groove 22, and the outer circumferential side from the groove bottom surface of the fitting groove 22. Protruding. In this embodiment, the covering rubber 24 fixed to the inner side surface of the fitting groove 22 is widened outward in the axial direction at the circumferential intermediate portion, and the bottom wall connecting rubber 54 is widened to the widened portion.

  The partition wall connecting rubber 56 protrudes to the outer peripheral side at the axially intermediate portion of the bottom wall connecting rubber 54 and extends in the circumferential direction with a substantially constant axial dimension. On both sides in the axial direction across the partition wall connection rubber 56, connection grooves 58 having the bottom wall connection rubber 54 as the groove bottom surface and the partition wall connection rubber 56 and the covering rubber 24 as the groove side surfaces extend in the circumferential direction, respectively. Is formed. Furthermore, a sealing lip 60 that protrudes from the intermediate portion in the axial direction to the outer peripheral side is continuously formed on the protruding front end surface of the partition wall connecting rubber 56 over the entire length in the circumferential direction. In this embodiment, two seal lips 60, 60 that are spaced apart in the axial direction and extend in the circumferential direction in parallel are formed.

  As shown in FIG. 10, the connection rubber 52 is sandwiched in the circumferential direction between the circumferential ends of the orifice member 36 fitted in the other fitting groove 22. That is, the bottom wall portions of the first and second communication grooves 44, 46 in the orifice member 36 are pressed against the bottom wall connecting rubber 54 in the circumferential direction, and the bottom wall connecting rubber 54 has both ends in the circumferential direction of the orifice member 36. It is sandwiched between the parts in the circumferential direction. Furthermore, the circumferential end of the partition wall portion 48 of the orifice member 36 is pressed against the partition wall connecting rubber 56 in the circumferential direction, and the partition wall connecting rubber 56 is sandwiched between the circumferential end portions of the orifice member 36 in the circumferential direction. Yes.

  Thereby, the bottom wall connecting rubber 54 is compressed in the circumferential direction, and the partition wall connecting rubber 56 is compressed in the circumferential direction. In addition, when the outer cylinder member 14 is externally fitted to the integrally vulcanized molded product 23 to which the orifice member 36 is attached, both end portions in the circumferential direction of the orifice member 36 are displaced toward each other, thereby bottom wall connecting rubber. 54 and the partition connecting rubber 56 are compressed in the circumferential direction.

  Further, the partition wall connecting rubber 56 is not buckled and bent against the circumferential compressive force exerted between the circumferential ends of the orifice member 36 by appropriately setting the width dimension and the forming material. Compressed in the direction. In the present embodiment, the circumferential end portion of the partition wall portion 48 of the orifice member 36 includes a tapered portion 62 whose axial dimension gradually increases toward the circumferential outer side, and the circumferential outer side sandwiching the tapered portion 62 is It is thicker in the axial direction than the inside. The partition wall connecting rubber 56 has substantially the same axial dimension as the circumferential end of the partition wall portion 48 having a thick wall, so that the strength against the buckling of the partition wall connecting rubber 56 is sufficiently increased.

  Furthermore, the axial end wall portion 64 of the orifice member 36 that constitutes the axially outer side wall portion of the first and second communication grooves 44, 46 is more than the end portion of the partition wall portion 48 at the other end portion in the circumferential direction. The circumferential end of the shaft end wall 64 is in contact with the covering rubber 24 covering the groove side surface of the fitting groove 22 in the circumferential direction. Furthermore, a taper surface 66 that is gradually inclined outward in the axial direction toward the outer side in the circumferential direction is provided on the groove side surface in the axial direction outer side of the first and second communication grooves 44 and 46, and the fitting groove portion 22. At both ends in the circumferential direction of the covering rubber 24 covering the groove side surfaces, tapered surfaces 68 are provided which gradually incline toward the outer side in the axial direction. The tapered surfaces 66 and 68 are connected and expanded so as to be substantially continuous in the circumferential direction, and the partition wall 48 is thickened in the axial direction. In the formation portion, the first and second communication grooves 44 and 46 and the connection groove 58 are expanded outward in the axial direction, and the groove width is secured without being narrowed.

  The protruding height of the bottom wall connecting rubber 54 from the groove bottom surface of the fitting groove portion 22 is substantially the same as the radial thickness of the bottom wall portions of the first and second communication grooves 44, 46. The protruding front end surfaces of the wall connecting rubber 54 are continuously connected to each other at substantially the same radial position as the groove bottom surfaces of the first and second communication grooves 44 and 46 (see FIG. 1). Furthermore, the protruding height of the partition wall connecting rubber 56 from the bottom wall connecting rubber 54 is substantially the same as the protruding height of the partition wall portion 48 with respect to the bottom surfaces of the first and second communication grooves 44, 46. 56 protruding front end surfaces are continuously connected at substantially the same radial position as the protruding front end surface of the partition wall 48 (see FIG. 1).

  Then, the outer cylinder member 14 is extrapolated to the integrally vulcanized molded product 23 of the main rubber elastic body 16 to which the orifice member 36 is attached, and the outer cylinder member 14 is subjected to diameter reduction processing, whereby the orifice member 36. Is assembled between the integrally vulcanized molded product 23 of the main rubber elastic body 16 and the outer cylindrical member 14.

  Further, the circumferential groove 50 opened on the outer peripheral surface of the orifice member 36 is fluid-tightly covered with the outer cylinder member 14 to form a tunnel-shaped flow path, and the tunnel-shaped flow path is formed at both ends in the circumferential direction. , The first fluid chamber 32 and the second fluid chamber 34 communicate with each other. Thus, an orifice passage 70 that connects the first fluid chamber 32 and the second fluid chamber 34 to each other is formed using the circumferential groove 50. The orifice passage 70 has a passage sectional area (A) in which the resonance frequency of the flowing fluid (the tuning frequency of the orifice passage 70) takes into account the rigidity of the wall springs of the first fluid chamber 32 and the second fluid chamber 34. And the passage length (L) ratio (A / L) is set appropriately. In the present embodiment, the tuning frequency of the orifice passage 70 is tuned to a frequency corresponding to brake shimmy, brake judder or the like.

  Here, the partition connection rubber 56 separating the connection grooves 58, 58 is in contact with the inner peripheral surface of the outer cylinder member 14, and the space between the partition connection rubber 56 and the outer cylinder member 14 is fluid-tightly sealed. Yes. In the present embodiment, the seal lip 60 provided on the outer peripheral surface of the partition wall connecting rubber 56 is pressed against the inner peripheral surface of the outer cylinder member 14, so that the space between the partition wall connection rubber 56 and the outer cylinder member 14 is higher. It is sealed.

  In the suspension bush 10 having such a structure, the inner shaft member 12 is attached to the suspension arm, and the outer cylinder member 14 is attached to the vehicle body, so that the suspension arm and the vehicle body are connected in a vibration-proof manner. ing. When vibration having a frequency corresponding to a brake shimmy, a brake judder, or the like is input between the inner shaft member 12 and the outer cylinder member 14, the relative movement between the first fluid chamber 32 and the second fluid chamber 34 is achieved. Since the pressure fluctuation is generated and the fluid flow through the orifice passage 70 is generated, the vibration isolating effect based on the fluid flow action is exhibited. Since the orifice passage 70 is formed by the circumferential groove 50 that spirally extends without being folded back in the circumferential direction, the fluid flow is efficiently generated with a small flow resistance, and the vibration isolation effect based on the fluid flow action of the fluid. Is advantageous.

  Further, when the vehicle gets over the step, a large load is input between the inner shaft member 12 and the outer cylinder member 14, and the inner shaft member 12 and the outer cylinder member 14 are relatively displaced in one radial direction. Then, the stopper receiving portion 40 of the inner shaft member 12 and the orifice member 36 abuts via the stopper rubber 28 and the buffer rubber layer 42. Thereby, the relative displacement amount of the inner shaft member 12 and the outer cylinder member 14 is limited, and damage due to excessive deformation of the main rubber elastic body 16 is avoided.

  According to the suspension bush 10 having the structure according to the present embodiment, both circumferential ends of the orifice member 36 are pressed against the connecting rubber 52 in the circumferential direction. In the connection part of the part, obstruction of the fluid flow due to fluid leakage is avoided, and the vibration isolation effect by the orifice passage 70 is efficiently exhibited. In particular, the partition wall connection rubber 56 is compressed in the circumferential direction without buckling against the pressing of the orifice member 36, so that the partition wall connection rubber 56 and the partition wall connection rubber 56 and the outer cylinder member 14 are compressed. A gap is prevented from being generated between them, and the vibration-proof performance is prevented from being deteriorated due to leakage.

  Further, since the seal lip 60 is formed on the protruding front end surface of the partition wall connecting rubber 56 and pressed against the inner peripheral surface of the outer cylindrical member 14, the protruding front end surface of the partition wall connecting rubber 56 and the outer cylindrical member 14 are A short circuit of the orifice passage 70 between the overlapping surfaces with the inner peripheral surface is avoided, and the intended vibration isolation effect can be effectively obtained.

  Further, since the partition wall connecting rubber 56 has a sufficient thickness, the partition wall connecting rubber 56 is compressed in the circumferential direction without buckling. In addition, since the partition wall portion 48 pressed against the partition wall connection rubber 56 in the circumferential direction includes a taper portion 62, the circumferential end of the partition wall portion 48 has substantially the same thickness as the partition wall connection rubber 56. By preventing the formation of a level difference that hinders fluid flow at the connecting portion between the connection rubber 56 and the partition wall 48, the vibration isolation effect due to the fluid flow effect is effectively exhibited.

  Further, a taper surface 66 is provided on the groove side surface of the first and second communication grooves 44, 46, and a taper surface 68 is provided on the groove side surface of the connection groove 58. In the vicinity, the first and second communication grooves 44 and 46 and the connection groove 58 are extended to the outer peripheral side. Therefore, even if the circumferential end portions of the partition wall connecting rubber 56 and the partition wall portion 48 are thick in the axial direction, the axial dimension of the orifice passage 70 is ensured without being reduced, and is based on the fluid flow action. The anti-vibration effect is effectively exhibited at a predetermined tuning frequency.

  Moreover, the shaft end wall portion 64 is provided on the inner side in the circumferential direction with respect to the circumferential end portion of the orifice member 36, and the tapered surface 66 of the shaft end wall portion 64 and the tapered surface 68 of the covering rubber 24 are arranged in the circumferential direction. Since it is connected, the circumferential end of the shaft end wall 64 can be prevented from having a step on the outer wall of the orifice passage 70 in the axial direction without making the end of the shaft 70 extremely thin and sharp in the axial direction. Efficient fluid flow is achieved. In addition, since a certain amount of thickness is secured at the circumferential end of the shaft end wall 64, the sharp circumferential end of the shaft end wall 64 abuts against the covering rubber 24 to cause cracks. The trouble that the manufacturing worker touches the circumferential end of the shaft end wall 64 and is injured can be avoided.

  Further, the bottom surface of the first and second communication grooves 44 and 46 in the orifice member 36 and the bottom surface of the connection groove 58 of the connection rubber 52 are arranged so as to be continuous at substantially the same radial height. In the connecting portion between the first and second communication grooves 44 and 46 and the connecting groove 58, a step is prevented from being generated on the bottom surface of the groove. Therefore, the fluid flow in the passage length direction of the orifice passage 70 is not hindered by the connection portion between the first and second communication grooves 44 and 46 and the connection groove 58, and the vibration isolation effect by the smooth fluid flow. Efficient display is realized.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the orifice member 36 may be configured by combining three or more divided bodies on the circumference, or may be a single member that is not divided. Further, when the orifice member 36 is constituted by a set of halves, the set of halves may have different structures.

  The orifice passage 70 may extend in a circumferential spiral shape with a length of two or more rounds. In other words, three or more communication grooves may be opened on the circumferential end surface of the orifice member 36.

  Moreover, the taper part 62 of the partition part 48 is not essential, for example, the circumferential direction edge part of the partition part 48 may be substantially the same thickness as the circumferential direction intermediate part. Also in that case, it is desirable that the circumferential end of the partition wall portion 48 and the partition connecting rubber 56 have substantially the same thickness so that no step is generated.

  Further, when the partition wall portion 48 does not have the taper portion 62, the circumferential end portions of the first and second communication grooves 44 and 46 and the connection groove 58 need not be expanded outward in the axial direction. The tapered surface 66 and the tapered surface 68 of the covering rubber 24 may be omitted.

  The first and second communication grooves 44 and 46 and the connection groove 58 are preferably connected without a step as in the above-described embodiment, but the groove bottom surfaces of the first and second communication grooves 44 and 46 are used. And the protruding front end surface of the bottom wall connecting rubber 54 may have different radial positions, there may be a step on the groove bottom surface, and the circumferential end of the partition wall 48 and the partition connecting rubber 56 may have different thicknesses. The groove side surface may have a step.

  The present invention is not only applied to the suspension bush, but can also be applied to, for example, an engine mount, a body mount, a subframe mount, and a differential mount. The scope of application of the present invention is not limited to a fluid-filled cylindrical vibration isolator for automobiles. For example, the present invention is applicable to a fluid-filled cylindrical vibration isolator used for motorcycles, railway vehicles, industrial vehicles, and the like. Are also preferably applied.

10: Suspension bush (fluid-filled cylindrical vibration isolator), 12: Inner shaft member, 14: Outer cylinder member, 16: Rubber elastic body, 18: Intermediate sleeve, 20: Window, 22: Fitting groove, 24: Coated rubber, 26: Pocket portion, 32: First fluid chamber, 34: Second fluid chamber, 36: Orifice member, 38: Half split, 44: First communication groove, 46: Second Communication groove, 48: partition wall, 54: bottom wall connection rubber, 56: partition wall connection rubber, 60: seal lip, 64: shaft end wall, 66: taper surface, 68: taper surface, 70: orifice passage

Claims (7)

The inner shaft member and the outer cylindrical member are elastically connected by the main rubber elastic body, and a pair of pocket portions opened on the outer peripheral surface of the main rubber elastic body are covered with the outer cylindrical member, thereby providing an incompressible fluid. The first fluid chamber and the second fluid chamber that form relative pressure fluctuations when vibration is input are formed, and the first fluid chamber and the second fluid chamber are straddled across the first fluid chamber and the second fluid chamber in the circumferential direction. An extending orifice member is assembled between the main rubber elastic body and the outer cylindrical member, and the orifice member is formed with a communication groove that opens in the outer circumferential surface and extends in a circumferential spiral shape. In a fluid-filled cylindrical vibration damping device in which an orifice passage is formed to connect the first fluid chamber and the second fluid chamber to each other by covering the outer peripheral opening of the communication groove with the outer cylinder member.
Between the circumferential direction of said 1st fluid chamber and said 2nd fluid chamber, the fitting groove part extended in the circumferential direction is formed, and both ends which are mutually faced in the circumferential direction in the said orifice member are this fitting groove part And is fitted to one end of each circumferential direction,
A bottom wall connecting rubber projecting from the groove bottom surface to the outer peripheral side is provided in the circumferential middle portion in the fitting groove, and the bottom wall connecting rubber is sandwiched between both circumferential ends of the bottom wall of the orifice member. While
Bulkhead connecting rubber is formed in the middle portion of the bottom wall connecting rubber in the groove width direction so as to protrude to the outer peripheral side and abut against the inner peripheral surface of the outer cylindrical member, and open to both ends in the circumferential direction of the orifice member. A partition wall between the plurality of communication grooves is pressed against the partition connecting rubber from both sides in the circumferential direction, and the partition connecting rubber is compressed in the circumferential direction without buckling. Type cylindrical vibration isolator.   The fluid-filled cylindrical vibration isolator according to claim 1, wherein a bottom surface of the communication groove of the orifice member is positioned at the same radial position as the outer peripheral surface of the bottom wall connecting rubber.   The fluid-filled cylindrical vibration isolator according to claim 1 or 2, wherein a circumferential end portion of the partition wall in the orifice member is gradually thickened in the axial direction toward the outer side in the circumferential direction. A shaft end wall portion on the outer side in the axial direction of each of the plurality of communication grooves that opens at both ends in the circumferential direction of the orifice member is provided in the circumferential direction inner side than the partition wall portion, and the shaft end wall portion While the groove inner surface of the communication groove constituted by comprises a tapered surface that gradually slopes outward in the circumferential direction toward the outer side in the circumferential direction,
The surface of the covering rubber that covers the groove inner surface on the outer side in the axial direction of the fitting groove portion is a tapered surface that gradually slopes outward in the axial direction toward the inner side in the circumferential direction,
The fluid-filled cylindrical vibration isolator according to any one of claims 1 to 3, wherein the tapered surfaces are connected in the circumferential direction and continuously spread.   5. The fluid-filled cylindrical vibration damping device according to claim 1, wherein a seal lip protruding outward is formed on the outer peripheral surface of the partition wall connecting rubber over the entire length in the circumferential direction. apparatus.   The orifice member is composed of a pair of halves divided in the circumferential direction, and one of the halves extends across the first fluid chamber in the circumferential direction and the other half of the halves. The fluid-filled cylindrical vibration isolator according to any one of claims 1 to 5, wherein the split body extends across the second fluid chamber in the circumferential direction. An intermediate sleeve is extrapolated to the inner shaft member, the inner shaft member and the intermediate sleeve are elastically connected by the main rubber elastic body, and the outer cylinder member is externally fitted to the intermediate sleeve. ,
The pair of pocket portions formed in the main rubber elastic body open to the outer peripheral surface through a pair of windows formed in the intermediate sleeve, and the circumferential direction between the pair of windows in the intermediate sleeve The fluid-filled cylindrical vibration isolator according to any one of claims 1 to 6, wherein a fitting groove is formed.

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