JP2017172623A - Fluid filled cylindrical vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid sealed type cylindrical vibration-proof device having a new and improved structure also capable of realizing a vibration-proof performance based on a fluid flow behaviour with respect to an input vibration in an axial direction while assuring a vibration-proof performance based on the fluid flow behaviour with respect to an input vibration in a direction perpendicular to an axis.SOLUTION: A fluid sealed type cylindrical vibration-proof device 10 comprises a pair of first fluid chambers 90, 90 oppositely positioned while holding an inner shaft member 12 in a first direction perpendicular to an axis; a first orifice passage 94 for communicating the pair of first fluid chambers 90, 90 to each other; a pair of second fluid chambers 92, 92 oppositely positioned while holding the inner shaft member 12 in a second direction perpendicular to the axis different from the first direction perpendicular to the axis; and a second orifice passage 96 for communicating the pair of second fluid chambers 92, 92 to each other. Different shapes of axial wall parts between the pair of fluid chambers 92, 92 from each other cause a relative pressure variation to be generated between the pair of second fluid chambers 92, 92 when the axial vibration is inputted.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fluid-filled cylindrical vibration damping device in which an inner shaft member is disposed so as to penetrate an outer tubular member, and a vibration-proofing effect based on a fluid action of a fluid sealed inside is exhibited. is there.

  Conventionally, a fluid-filled cylindrical vibration isolator is known as a type of vibration isolator that is mounted between members constituting a vibration transmission system, and is used, for example, in an engine mount or a body mount for an automobile. Yes. As described in JP 2010-159873 A (Patent Document 1), such a cylindrical vibration isolator generally has an inner shaft member and an outer attached to each member constituting a vibration transmission system. The cylindrical member is connected to the rubber elastic body of the main body so that a vibration-proofing effect based on the fluid action of the sealed fluid generated at the time of vibration input is exhibited.

  By the way, in the vibration isolator, a plurality of vibrations may be input from different directions. And the vibration-proof effect is each requested | required with respect to each of those vibrations. For example, as described in Patent Document 1, when vibrations are input in a plurality of directions perpendicular to the axis, a plurality of pairs of fluid chambers that are opposed to each other with an inner shaft member interposed therebetween are formed in each direction. By communicating with the orifice passage, it is possible to obtain an anti-vibration effect based on the fluid flow action with respect to the input vibration in each direction.

  However, in the case of the cylindrical vibration isolator, it is difficult to cope with the case where an anti-vibration effect is required for the input vibration in the axial direction in addition to the input vibration in the direction perpendicular to the axis. Since the relative displacement between the inner shaft member and the outer cylindrical member due to the input vibration in the axial direction is a parallel displacement in the axial direction, it is formed between the radially opposed surfaces of the inner shaft member and the outer cylindrical member. This is because pressure fluctuation is unlikely to occur in the fluid chamber. In particular, it has been more difficult to achieve the vibration isolating performance based on the fluid flow action against the input vibration in the axial direction while securing the vibration isolating performance based on the fluid flow action against the input vibration in the direction perpendicular to the axis.

JP 2010-159873 A

  The present invention has been made in the background as described above, and the problem to be solved is that the input vibration in the axial direction is secured while ensuring the vibration isolation performance based on the fluid flow action against the input vibration in the direction perpendicular to the axis. It is an object of the present invention to provide a fluid-filled cylindrical vibration isolator having a novel structure capable of realizing a vibration isolating performance based on a fluid flow action.

  In the first aspect of the present invention, the inner shaft member is disposed through the outer cylinder member, the inner shaft member and the outer cylinder member are connected by a main rubber elastic body, and are not compressed. In the fluid-filled cylindrical vibration isolator having a fluid chamber in which a compressive fluid is enclosed and exhibiting a vibration isolating effect based on the flow action of the incompressible fluid, the inner shaft member is perpendicular to the first axis. A pair of first fluid chambers opposed to each other across the direction and a first orifice passage communicating the pair of first fluid chambers with each other, Are provided with a pair of second fluid chambers opposed to each other in a direction perpendicular to the second axis across the inner shaft member, and a second orifice passage communicating the pair of second fluid chambers with each other. A sealing region of the incompressible fluid in the first fluid chamber and the The incompressible fluid sealing regions in the two fluid chambers are formed independently of each other, and the shape of the axial wall portion is different between the pair of second fluid chambers. The fluid-filled cylindrical vibration isolator is characterized in that a relative pressure fluctuation is generated between the pair of second fluid chambers when a directional vibration is input.

  In the fluid-filled cylindrical vibration isolator having the structure according to this aspect, the fluid chamber in which the incompressible fluid is sealed includes each of the pair of first and second fluid chambers. When a vibration is input in a direction perpendicular to the axis at which the pair of first fluid chambers face each other, a relative pressure fluctuation is positively induced between the pair of fluid chambers, so that the fluid flowing through the first orifice passage Anti-vibration effect based on resonance action is exhibited. In addition, when axial vibration is input, the shape of the axial wall portion is different from each other, so that a relative pressure fluctuation is generated between the pair of second fluid chambers, and the fluid flows through the second orifice passage. An anti-vibration effect based on the resonance action of the fluid will be exhibited.

  According to a second aspect of the present invention, there is provided a fluid-filled cylindrical vibration isolator according to the first aspect, wherein an inner surface of an axial wall portion located at least one of the pair of second fluid chambers in the axial direction. Are inclined in opposite directions in the axial direction between the pair of second fluid chambers.

  In the fluid-filled cylindrical vibration isolator of this aspect, the inner shaft member is displaced relative to the outer cylinder member in the axial direction when the axial vibration is input, so that one of the second fluid chambers is axially moved. While the inner surface of the inclined axial wall portion is compressed (or tensile) deformed, in the other second fluid chamber, the inner surface of the axial wall portion inclined in the opposite axial direction is tensile (or compressed) deformed. You will be harassed.

  A pressurizing action is exerted in the fluid chamber in which the inner surface of the axial wall portion is compressed and deformed, whereas a depressurizing action is exerted in the fluid chamber in which the inner surface of the axial wall portion is tensilely deformed. As a result, relative pressure fluctuations are more actively generated between the paired second fluid chambers, and the vibration isolation performance is improved as the amount of fluid flow through the second orifice passage increases. Can be achieved.

  In this aspect, the inclination directions of the inner surfaces of the axial wall portions of the pair of second fluid chambers may be opposite to each other only on one side in the axial direction, and the pair of axial sides on the other side may also be paired. The inclination directions of the inner surface of the axial wall portion of the second fluid chamber may be opposite to each other.

  According to a third aspect of the present invention, in the fluid-filled cylindrical vibration isolator according to the first or second aspect, the main rubber elastic body is divided into three divided rubber elastic members divided into an axial center and both sides. And the same split rubber elastic body on both axial sides constituting the axial wall portions of the pair of first fluid chambers and the pair of second fluid chambers is inverted in the axial direction. It is used.

  In the fluid-filled cylindrical vibration isolator of this aspect, the main rubber elastic body is composed of three divided rubber elastic bodies, so that the shape design freedom of each divided rubber elastic body and thus the main rubber elastic body can be reduced during molding. It is ensured greatly by reducing the restrictions due to the die-cutting structure. Moreover, by inverting in the axial direction to form two divided rubber elastic bodies, the number of parts can be substantially suppressed. Furthermore, by inverting the two divided rubber elastic bodies in the axial direction, for example, one axial wall portion of one second fluid chamber and the other axial wall of the other second fluid chamber are paired. It is also easy to realize the second aspect by setting the inclination directions to be opposite to each other in the axial direction.

  A fourth aspect of the present invention is a fluid-filled cylindrical vibration isolator according to any one of the first to third aspects, wherein the pair of second fluid chambers are positioned on opposite sides in the axial direction. The thickness dimension of the axial wall portion is thicker than any of the other axial wall portion and the axial wall portions of the pair of first fluid chambers.

  In the fluid-filled cylindrical vibration isolator of this aspect, by adopting a thin axial wall portion, the shape and inclination angle of the thin axial wall portion are appropriately determined in consideration of the axial vibration isolation characteristics. When set to, adverse effects on the anti-vibration characteristics in the direction perpendicular to the axis can be suppressed. Further, by adopting the thin axial wall portion, for example, the axial wall portion is inclined in the axial direction while suppressing the increase in the axial total length of the axial wall portion and the increase in the axial size of the vibration isolator. It is also possible to set a large angle.

  According to a fifth aspect of the present invention, there is provided the fluid-filled cylindrical vibration damping device according to any one of the first to fourth aspects, wherein the second fluid chamber is axially positioned on both sides in the axial direction. In the wall portion, at least one of the axial thickness dimension and the inclination direction is different from each other.

  In the fluid-filled cylindrical vibration isolator of this aspect, the pressure induced in the second fluid chamber with respect to the axial vibration by relatively adjusting the thickness dimension and the inclination direction of the both axial side walls. It is possible to effectively tune the vibration isolation performance in the axial direction by adjusting the fluctuation.

  A sixth aspect of the present invention is a fluid-filled cylindrical vibration isolator according to any one of the first to fifth aspects, and is a separate body extending in the circumferential direction on the outer peripheral surface of the main rubber elastic body. An orifice member is mounted, and an inner peripheral flow path is provided between the main rubber elastic body and the orifice member, and an outer peripheral flow path is provided between the orifice member and the outer cylinder member. The first orifice passage and the second orifice passage are formed using the inner peripheral flow path and the outer peripheral flow path.

  In the fluid-filled cylindrical vibration isolator of this aspect, the first and second orifice passages are formed by using the inner peripheral side and the outer peripheral side of the orifice member. It can be ensured more efficiently. In addition, since the orifice member is formed separately from the main rubber elastic body, the shapes of the first and second orifice passages can be easily designed and changed, and the first and second orifice passages can be formed. The degree of freedom in tuning the resonance frequency at can be improved.

  A seventh aspect of the present invention is a fluid-filled cylindrical vibration isolator according to the sixth aspect, wherein a pair of the orifice members are provided and face each other in a direction perpendicular to the axis with the inner shaft member interposed therebetween. The same member is used as the pair of orifice members.

  In the fluid-filled cylindrical vibration isolator of this aspect, since the same member is used as the pair of orifice members, the number of parts can be substantially reduced and one of the main rubber elastic bodies in the direction perpendicular to the axis can be reduced. There is no need to distinguish the other, and the ease of assembly of the orifice member and the main rubber elastic body can be improved.

  In the fluid-filled cylindrical vibration isolator constructed according to the present invention, a relative pressure fluctuation is positively generated between a pair of fluid chambers when vibration is input in a direction perpendicular to the axis where the pair of first fluid chambers face each other. By being induced, an anti-vibration effect based on the resonance action of the fluid flowing through the first orifice passage is exhibited. In addition, when axial vibration is input, the shape of the axial wall portion is different from each other, so that a relative pressure fluctuation is generated between the pair of second fluid chambers, and the fluid flows through the second orifice passage. An anti-vibration effect based on the resonance action of the fluid will be exhibited.

1 is a plan view showing a fluid-filled cylindrical vibration isolator as one embodiment of the present invention. II-II sectional drawing in FIG. III-III sectional drawing in FIG. IV-IV sectional drawing in FIG. VV sectional drawing in FIG. The disassembled perspective view for demonstrating the assembly | attachment structure of the division | segmentation rubber | gum elastic body and orifice member which comprise the fluid enclosure type | formula vibration isolator shown by FIG. The perspective view which shows the center elastic body which is one of the division | segmentation rubber | gum elastic bodies shown by FIG. 6 in the state of an integral vulcanization molded product. FIG. 8 is a front view of the integrally vulcanized molded product shown in FIG. 7. The perspective view which shows the edge part elastic body which is one of the division | segmentation rubber | gum elastic bodies shown by FIG. 6 in the state of an integral vulcanization molded product. The perspective view from another angle of the integral vulcanization molded product shown in FIG. The perspective view which shows the orifice member shown by FIG. The perspective view from another angle of the orifice member shown by FIG.

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

  First, FIGS. 1 to 5 show an engine mount 10 for an automobile as an embodiment of a fluid-filled cylindrical vibration isolator according to the present invention. The engine mount 10 has a structure in which an inner shaft member 12 and an outer cylinder member 14 are connected by a main rubber elastic body 16. The inner shaft member 12 is attached to one of the power unit and the vehicle body constituting the vibration transmission system, and the outer cylinder member 14 is attached to the other of the power unit and the vehicle body, thereby preventing the power unit from the vehicle body. It is designed to be swing-coupled. In the following description, the axial direction refers to the horizontal direction in FIG. 2 that is the mount central axis direction. Further, the direction perpendicular to the axis is a direction perpendicular to the center axis of the mount, for example, the vertical direction in FIG. 2 or the horizontal direction in FIG.

  More specifically, the inner shaft member 12 is a highly rigid member formed of a metal such as iron or aluminum alloy, a hard synthetic resin, or the like, and as a whole, a relatively thick cylinder extending in the axial direction. It is made into a shape. That is, a central hole 18 penetrating in the axial direction is formed in the center of the inner shaft member 12. Further, a pair of stopper projections 20, 20 projecting to the outer peripheral side are provided on the outer peripheral surface on both sides in the axis-perpendicular direction (both sides in the vertical direction in FIG. 2) in the central portion of the inner shaft member 12 in the axial direction. . By providing the stopper protrusions 20 and 20, as shown in FIG. 4 and the like, the cross section in the axial central portion of the inner shaft member 12 has a substantially oval shape.

  On the other hand, the outer cylinder member 14 is formed of a member similar to the inner shaft member 12 and is a cylindrical member that is thinner and larger in diameter than the inner shaft member 12 and extends in the axial direction. A thin seal rubber layer 22 is fixed to the inner peripheral surface of the outer cylinder member 14 over the entire surface.

  Center axes of the inner shaft member 12 and the outer cylinder member 14 are aligned with each other, and the inner shaft member 12 is inserted into the outer cylinder member 14. The axial dimension of the inner shaft member 12 is longer than the axial dimension of the outer cylinder member 14, and the inner shaft member 12 protrudes outward in the axial direction from both axial ends of the outer cylinder member 14. . A main rubber elastic body 16 is provided between the inner shaft member 12 and the outer cylinder member 14 in the radial direction.

  As shown in FIG. 6, the main rubber elastic body 16 is composed of a divided rubber elastic body that is divided into three in the axial direction. That is, the main rubber elastic body 16 of the present embodiment has a divided structure including a central elastic body 24 that forms an axial central portion and a pair of end elastic bodies 26 and 26 that form both axial end portions. Yes.

  As shown in FIGS. 7 and 8, the central elastic body 24 has a relatively thick, generally cylindrical shape as a whole, and is formed on the inner peripheral surface of the central hole 28 formed through the center in the axial direction. The inner shaft member 12 is vulcanized and bonded to the outer peripheral surface. In addition, a pair of first straight holes 30, 30 that are opposed to each other in a direction perpendicular to the axis (vertical direction in FIG. 8) with the central hole 28 interposed therebetween penetrate the central elastic body 24 in the radial direction. Is formed. Further, in the direction perpendicular to the opposing direction of the first straight holes 30 and 30 (left and right direction in FIG. 8), the second straight holes 32 and 32 facing each other across the central hole 28 penetrate in the axial direction. Is formed.

  In the following description, the direction perpendicular to the axis where the pair of first bore holes 30, 30 are opposed is referred to as a first axis perpendicular direction. Further, a direction perpendicular to the axis where the pair of second straight holes 32 and 32 face each other is referred to as a second direction perpendicular to the axis.

  The first and second straight holes 30 and 30 and the second straight holes 32 and 32 are located on substantially the same circumference, and are spread in a predetermined dimension in the circumferential direction. In the present embodiment, the first straight holes 30, 30 have a larger circumferential dimension than the second straight holes 32, 32, and the first straight holes 30, 30 are second. The radial width dimension is made smaller than that of the straight holes 32, 32.

  As described above, the four straight holes 30, 30, 32, and 32 are provided at a predetermined distance in the circumferential direction, so that the central elastic body 24 has the first straight hole 30 adjacent to the circumferential direction and the first straight holes 30. A total of four arm portions 34, 34, 34, 34 are formed extending in the radial direction, located between the circumferential directions of the two tick holes 32. In other words, the four arm portions 34, 34, 34, 34 are formed at a predetermined distance in the circumferential direction, so that the adjacent arm portions 34, 34 face each other in the first axis perpendicular direction. A pair of first straight holes 30 and 30 and a pair of second straight holes 32 and 32 facing each other in the direction perpendicular to the second axis are formed independently of each other.

  In addition, a pair of circumferential grooves 36 and 36 that open to the outer peripheral side and extend in the circumferential direction are formed on the outer peripheral surface of the central elastic body 24 on the outer peripheral side of the second straight holes 32 and 32. These circumferential grooves 36 and 36 are each formed with a circumferential dimension less than a half circumference, and are opposed in the second axis perpendicular direction. Further, a pair of connecting grooves 38, 38 that open to the outer peripheral side are provided between the circumferential grooves 36, 36, that is, in a portion where the peripheral grooves 36, 36 are not provided on the outer peripheral surface of the central elastic body 24. Is provided.

  Each connection groove 38 extends in the circumferential direction, and connects the circumferential grooves 36 and 36 located on both sides in the circumferential direction of the connection groove 38. The connection grooves 38 are opposed to each other in the direction perpendicular to the first axis. The groove length dimension of the connection groove 38 is shorter than the groove length dimension of the circumferential groove 36. Further, the groove width dimension of the connection groove 38 (the horizontal dimension in FIG. 2) is smaller than the groove width dimension of the circumferential groove 36, and the groove depth dimension of the connection groove 38 is the groove depth of the circumferential groove 36. It is smaller than the size. In particular, in the present embodiment, the connection groove 38 extends incline from one side in the axial direction toward the other side between the circumferential ends of the circumferential grooves 36 and 36 adjacent in the circumferential direction.

  Furthermore, first through holes 40, 40 extending in the direction perpendicular to the axis are formed in the outer peripheral wall portion constituting the first straight holes 30, 30, and the first through holes 40, 40 are formed. The circumferential grooves 36 and 36 are open at the groove bottom surfaces. That is, the internal space of each first straight hole 30 communicates with the external space (the internal space of the circumferential groove 36) through the first through hole 40. On the other hand, second through holes 42, 42 extending in the direction perpendicular to the axis are formed in the outer peripheral wall portion constituting the second straight holes 32, 32, and the second through holes 42, 42 are formed. The circumferential grooves 36 and 36 are open at the groove bottom surfaces. That is, the internal space of each second straight hole 32 communicates with the external space (the internal space of the circumferential groove 36) through the second through hole 42.

  Furthermore, an intermediate sleeve 44 is embedded in the central elastic body 24. The intermediate sleeve 44 has a cylindrical shape extending in the axial direction as a whole, and the axial intermediate portion is smaller in diameter than both axial end portions and is positioned on the inner peripheral side. In the intermediate sleeve 44, through-holes penetrating in the thickness direction are formed at positions corresponding to the first and second through-holes 40, 40, 42, 42, and the first and second straight holes are formed. Communication between the internal space of 30, 30, 32, 32 and the internal space of the circumferential grooves 36, 36 is realized. By providing the intermediate sleeve 44, the circumferential grooves 36, 36 and the first and second straight holes 30, 30, 32, 32 are formed stably.

  As shown in FIGS. 7 and 8, the central elastic body 24 of the present embodiment is formed as an integrally vulcanized molded product 46 including the inner shaft member 12 and the intermediate sleeve 44. That is, the central elastic body 24 is fixed to the central portion of the inner shaft member 12 in the axial direction, and the central elastic body 24 is fixed to the inner and outer peripheral surfaces of the intermediate sleeve 44. And since the axial direction dimension of the center elastic body 24 is made smaller than the inner shaft member 12, the inner shaft member 12 protrudes from the center elastic body 24 in the axial direction both sides in the integral vulcanization molded product 46.

  The axially opposite side portions of the intermediate sleeve 44 having a large diameter are positioned on the substantially outer peripheral surface of the central elastic body 24 so that the outer cylinder member 14 is fitted and fixed. Thus, the outer peripheral portion of the central elastic body 24 that is arranged on the outer peripheral side of the intermediate sleeve 44 and forms the peripheral grooves 36 and 36 and the connection grooves 38 and 38 is surrounded by the intermediate sleeve 44 and the outer cylindrical member 14. Thus, vibrations and loads from the outside are not substantially applied.

  On the other hand, the pair of end elastic bodies 26, 26 constituting both ends of the main rubber elastic body 16 in the axial direction have the same shape, and are mutually inverted in the axial direction so that the same surface becomes the central elastic body 24. In this state, it is assembled to the integrally vulcanized molded product 46 of the central elastic body 24. In addition, since a pair of edge part elastic bodies 26 and 26 are mutually the same shape, in the following description, one edge part elastic body 26 is demonstrated.

  That is, as shown in FIGS. 9 and 10, the end elastic body 26 has a substantially annular plate shape, and a central hole 48 for assembling the inner shaft member 12 in an extrapolated state at the center. Is provided penetrating in the axial direction. In addition, of the axially opposite surfaces of the end elastic body 26, the axially outer surface 50 that constitutes the axially outer surface when assembled to the integral vulcanized product 46 is a surface shape that is rotationally symmetric about the central axis. It is said that. The axial outer surface 50 has a curved concave shape that gradually protrudes outward in the axial direction toward the inner peripheral side.

  The axial inner surface 51 of the end elastic body 26 has a different surface shape in the circumferential direction. And in the radial direction intermediate part in the axial direction inner surface 51 of the edge part elastic body 26, the three concave shaped hole 52,52,54 is formed in the circumferential direction.

  That is, the axial inner surface 51 of the end elastic body 26 is formed with a pair of straight holes 52, 52 on both sides (upper and lower sides in FIG. 2) opposed to each other in the direction perpendicular to the first axis. Further, a counterbore 54 is formed on one side (the left side in the upper end elastic body 26 in FIG. 3) that is opposed to the second axis at right angles. On the other hand, the other side (the right side in the upper end elastic body 26 in FIG. 3) facing the second axis perpendicular direction is not formed with a straight hole, and in this embodiment, The inclined surface 56 is gradually inclined inward in the axial direction toward the inner peripheral side.

  Further, on both sides in the circumferential direction of the straight hole 54 in the end elastic body 26, arm portions 58 and 58 extending in the radial direction between the adjacent straight holes 52 and 52 are formed. In the present embodiment, the three straight holes 52, 52, 54 are located on the same circumference and are substantially the same, and have an opening shape and a hole depth of substantially the same size. .

  Further, in the end elastic body 26, the axial inner and outer surfaces 51, 50 are shaped as described above, so that the thickness (axial dimension) of the end elastic body 26 is different in the circumferential direction. In other words, the thickness of the end elastic body 26 is relatively small in the portion where the straight holes 52, 52, 54 are provided, and the axially outer wall of the straight holes 52, 52, 54 is formed. Thin portions 60, 60, 60 are formed by the portions. On the other hand, a portion where the tick hole is not provided, that is, a portion where the inclined surface 56 is provided is a thick portion 62 that is relatively thicker than the thin portions 60, 60, 60.

  In the present embodiment, the thickness dimensions of the thin portions 60, 60, 60 formed by the straight holes 52, 52, 54 are equal to each other. Further, the bottom wall surfaces of the straight holes 52, 52, and 54 and the axially outer surface 50 of the end elastic body 26 are substantially parallel, and each thin-walled portion 60 has a substantially constant wall thickness over substantially the whole. ing. As a result, local strain and stress concentration in the thin portion 60 are avoided or reduced.

  Further, an inner peripheral side metal fitting 64 and an outer peripheral side metal fitting 66 are fixed to the inner peripheral portion and the outer peripheral portion of the end elastic body 26. The inner peripheral side metal fitting 64 and the outer peripheral side metal fitting 66 have a substantially cylindrical shape as a whole, and in this embodiment, the inner peripheral side metal fitting 64 and the outer peripheral surface with respect to the inner peripheral surface and the outer peripheral surface of the end elastic body 26. The side metal fitting 66 is vulcanized and bonded, and as shown in FIGS. 9 and 10, the end elastic body 26 is formed as an integrally vulcanized molded product 72 having an inner metal fitting 64 and an outer metal fitting 66. . The central hole 48 of the end elastic body 26 is constituted by the inner hole of the inner peripheral side metal fitting 64.

  Note that the end portion on the axial outer surface 50 side of the inner peripheral side metal fitting 64 is bent toward the outer peripheral side to form an annular flange portion 68. Further, the end on the axial inner surface 51 side of the outer peripheral metal fitting 66 is bent toward the inner peripheral side to form an annular flange portion 70.

  Further, a pair of orifice members 74 are mounted on the central elastic body 24 (integrated vulcanized product 46) of the main rubber elastic body 16. These orifice members 74, 74 are oppositely arranged opposite to each other across the inner shaft member 12 in the second axis-perpendicular direction (left-right direction in FIG. 3). Are inserted into the circumferential grooves 36, 36.

  That is, the orifice member 74 is a metal or hard synthetic resin member that is curved and extends in the circumferential direction with a predetermined width dimension (vertical direction dimension in FIG. 3), and the circumferential groove of the central elastic body 24. It has substantially the same circumferential dimension as 36. It is desirable that both the outer surfaces in the width direction of the orifice member 74 are in close contact with the inner surfaces of both side walls in the width direction of the circumferential groove 36.

  Further, on the outer surface of the orifice member 74, a first groove portion 76 and a second groove portion 78 are formed which are formed of two parallel grooves that open to the outer peripheral side and extend in the circumferential direction. Furthermore, a third groove portion 80 and a fourth groove portion 82 are formed on the inner surface of the orifice member 76. The third groove portion 80 and the second groove portion 82 are formed of two parallel grooves that open to the inner peripheral side and extend in the circumferential direction.

  The third groove 80 is provided with a wall 84 at a predetermined position in the groove length direction, and the third groove 80 is blocked at a predetermined position in the groove length direction. Further, the first groove portion 76 and the third groove portion 80 formed on the front and back surfaces of the orifice member 74 with the groove bottom wall portion in common are one end portion in the circumferential direction (the lower end portion in FIGS. 11 and 12). Are connected through a notch 86 formed in the groove bottom wall. Furthermore, the second groove part 78 and the fourth wall part 82 formed on the front and back of the orifice member 74 with the groove bottom wall part in common are the other ends in the circumferential direction (the upper end in FIGS. 11 and 12). Part) through the notch 88 formed in the groove bottom wall.

  Then, as shown in FIG. 6, the end elastic bodies 26, 26 are assembled to the central elastic body 24 from both sides in the axial direction with the front and back being reversed in the axial direction. The engine mount 10 of the present embodiment is configured by fitting the orifice members 74 and 74 into 36 and 36, and further inserting the outer cylinder member 14 into these assemblies.

  That is, the integral vulcanization molded product 72 of the end elastic body 26 is extrapolated with respect to one axial direction of the inner shaft member 12 protruding from the integral vulcanized molded product 46 of the central elastic body 24, and the inner shaft member 12 The integral vulcanization molded product 72 of the end elastic body 26 is reversed and extrapolated with respect to the other in the axial direction. As a result, both axial ends of the first straight holes 30, 30 penetrating the central elastic body 24 in the axial direction are closed by the end elastic bodies 26, 26, and the first axis is perpendicular to the inner shaft member 12. A pair of first fluid chambers 90, 90 facing each other in the direction are formed. Moreover, the axial direction both sides of the 2nd straight holes 32 and 32 are obstruct | occluded by the edge part elastic bodies 26 and 26, A pair of 2nd 2nd which opposes a 2nd axis perpendicular direction on both sides of the inner shaft member 12 is sandwiched. Fluid chambers 92 and 92 are formed. In addition, in the part in which the 1st hole 30 and 30 and the 2nd hole 32 and 32 are provided mutually independently, and those holes 30 and 30, 32, 32 are not formed, Since the central elastic body 24 and the end elastic bodies 26 and 26 are closely adhered and overlapped in the axial direction, the first fluid chambers 90 and 90 and the second fluid chambers 92 and 92 are also independent of each other. Is formed.

  These first and second fluid chambers 90, 90, 92, 92 are filled with an incompressible fluid. Further, the incompressible fluid to be enclosed is not limited in any way, but any of water, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof can be suitably used. In order to effectively obtain a vibration isolation effect based on the fluid flow action described later, the incompressible fluid is desirably a low viscosity fluid of 0.1 Pa · s or less.

  Here, the inner shaft member 12 is press-fitted into the central hole 48 of the end elastic body 26 so that the end elastic body 26 (integrated vulcanized molded product 72) is applied to the central elastic body 24 (integrated vulcanized molded product 46). It can be positioned by abutting or the like. In particular, since the inner peripheral side metal fitting 64 and the outer peripheral side metal fitting 66 are provided in the integrally vulcanized molded product 72 of the end elastic body 26, the central elastic body 24 (integrated vulcanized molded product 46) and the end elastic body are provided. 26, 26 (integrated vulcanized molded products 72, 72) are positioned with high accuracy. Further, by performing such assembly in an incompressible fluid, it is easy to enclose the incompressible fluid in the first and second fluid chambers 90, 90, 92, 92.

  Further, the outer cylindrical member 14 is extrapolated to the assembly of the central elastic body 24 (integrated vulcanized molded product 46) and the end elastic bodies 26, 26 (integrated vulcanized molded products 72, 72). The outer cylinder member 14 is subjected to diameter reduction processing, so that the internal fluid sealing region including the first and second fluid chambers 90, 90, 92, 92 is closed in a liquid-tight state with respect to the external space. Is done.

  Then, the openings of the third groove portions 80 and 80 and the fourth groove portions 82 and 82 located on the inner peripheral side of the orifice members 74 and 74 are covered with the groove bottom wall portions of the peripheral grooves 36 and 36. Accordingly, a tunnel-like inner peripheral flow path is formed on the inner peripheral side of the orifice members 74 and 74 by the third groove portions 80 and 80 and the fourth groove portions 82 and 82, respectively. At the same time, the opening portions of the first groove portions 76 and 76 and the second groove portions 78 and 78 located on the outer peripheral side of the orifice members 74 and 74 are covered with the outer cylinder member 14 through the seal rubber layer 22. Therefore, the first groove portions 76 and 76 and the second groove portions 78 and 78 form a tunnel-shaped outer peripheral flow path on the outer peripheral side of the orifice members 74 and 74, respectively.

  As a result, the second groove portions (outer peripheral side flow passages) 78 and 78 and the fourth groove portions (inner peripheral side flow passages) 82 and 82 of the pair of orifice members 74 and 74 and the first through holes 40 and 40 are cut. A first orifice passage 94 that connects the pair of first fluid chambers 90, 90 to each other is configured using the notches 88, 88 and the connection groove 38. In addition, the first groove portions (outer peripheral flow paths) 76 and 76 and the third groove portions (inner peripheral flow paths) 80 and 80 of the pair of orifice members 74 and 74, the second through holes 42 and 42, and notches A second orifice passage 96 that connects the pair of second fluid chambers 92 and 92 to each other is configured by using the 86 and 86 and the connection groove 38.

  Thus, since the first orifice passage 94 and the second orifice passage 96 are formed independently of each other, the non-compression in the first fluid chambers 90 and 90 including the first orifice passage 94 is performed. The sealing region for the compressive fluid and the sealing region for the incompressible fluid in the second fluid chambers 92 and 92 including the second orifice passage 96 are formed independently of each other.

  The orifice passages 94 and 96 are adjusted by adjusting the ratio (A / L) of the passage sectional area (A) and the passage length (L) of the first orifice passage 94 and the second orifice passage 96. However, in this embodiment, the frequency of the first orifice passage 94 that is to be subjected to vibration isolation is tuned to the frequency of the vibration that is input in the direction perpendicular to the axis. On the other hand, the frequency of the second orifice passage 96 that is subject to vibration isolation is tuned to the frequency of vibration that is input in the axial direction and is to be subjected to vibration isolation. In the present embodiment, the orifice passages 94 and 96 are formed so as to extend over the front and back surfaces of the orifice members 74 and 74. Therefore, a large degree of freedom in designing the orifice tuning and the orifice tuning can be secured. It is like that.

  Here, the first straight holes 30, 30 in the central elastic body 24 and the straight holes 52, 52, 52, 52 in the end elastic bodies 26, 26 are aligned in the circumferential direction. Thus, both axial wall portions of the first fluid chamber 90 are constituted by the thin-walled portions 60, 60.

  In addition, since the end elastic bodies 26 and 26 are configured by inverting the same member, the inclination directions of the both axial walls (thin portions 60 and 60) in the first fluid chamber 90 are inverted. . Here, the inclination direction of the axial wall portion in the first fluid chamber 90 is the direction of the elastic main axis L1 extending in the radial direction in the rubber elastic body constituting the axial wall portion (thin wall portion 60). L1 is schematically shown by a one-dot chain line. That is, the inclination directions of the axial wall portions constituting the first fluid chambers 90 and 90 are both inclined in the axially outward direction toward the inner peripheral side.

  Further, since the shapes of the straight holes 52, 52, 52, 52 provided in the first fluids 30, 30, and the end elastic bodies 26, 26 are equal to each other, the shapes of the first fluid chambers 90, 90 are the same. Is symmetrical with respect to the mount center axis M. That is, for example, in the longitudinal sectional view shown in FIG. 2, the shapes of the first fluid chambers 90, 90 are vertically symmetrical with respect to the mount center axis M.

  On the other hand, the second straight holes 32 and 32 in the central elastic body 24 and the straight holes 54 and the inclined surfaces 56 in the end elastic bodies 26 and 26 are aligned in the circumferential direction. As a result, both axial wall portions of the second fluid chamber 92 are constituted by the thin portion 60 and the thick portion 62. That is, in one second fluid chamber 92, one axial wall portion is the thin wall portion 60 and the other axial wall portion is the thick wall portion 62. On the other hand, in the other second fluid chamber 92, one axial wall portion is a thick portion 62 and the other axial wall portion is a thin portion 60.

  Here, the elastic main axis L1 of the rubber elastic body constituting the thin portion 60 is the same as the first fluid chambers 90, 90. On the other hand, the elastic main axis L2 of the rubber elastic body constituting the thick portion 62 is as shown by a one-dot chain line L2 in FIG. 3, and the inclination direction (inclination angle with respect to the axial direction) is different from the elastic main axis L1 of the thin portion 60. ing. Specifically, L2 is substantially parallel to the direction perpendicular to the axis or slightly inclined in a direction inclined inward in the axial direction toward the inner peripheral side, and has a larger inclination angle with respect to the axial direction than L1 (axis The inclination angle with respect to the perpendicular direction is small).

  In particular, on one side in the axial direction (upper side in FIG. 3), the inner surfaces of the axial wall portions of the pair of second fluid chambers 92 and 92 are inclined with respect to the direction perpendicular to the axis, respectively. Are opposed to each other. That is, the inner surface of the second fluid chamber 92 on one side (left side in FIG. 3) (the bottom surface of the straight hole 54) is inclined inward in the axial direction from the radially inner side to the outer side. On the other hand, the inner surface (inclined surface 56) of the other second fluid chamber 92 is inclined outward in the axial direction from radially inward to outward.

  Further, on the other side in the axial direction (the lower side in FIG. 3), the inner surfaces of the axial wall portions of the pair of second fluid chambers 92, 92 are inclined with respect to the direction perpendicular to the axis, respectively. The inclination directions are opposite to each other. That is, the inner surface of the second fluid chamber 92 on one side (right side in FIG. 3) (the bottom surface of the straight hole 54) is inclined inward in the axial direction from the radially inner side to the outer side. On the other hand, the inner surface (inclined surface 56) of the other second fluid chamber 92 is inclined outward in the axial direction from radially inward to outward.

  That is, as is apparent from FIG. 3, in the second fluid chamber 92 on the left side and the second fluid chamber 92 on the right side in FIG. The second fluid chambers 92 are opposite to each other. Specifically, the inner surfaces 54, 56 of both axial walls of the second fluid chamber 92 on the left side gradually incline downward as going outward in the radial direction, while the second side chamber on the right side Both inner surfaces 54 and 56 of both axial walls of the fluid chamber 92 are gradually inclined upward as they go radially outward.

  Therefore, in the second fluid chambers 92 and 92, the shapes of the axial wall portions are different from each other. Therefore, the shapes of the second fluid chambers 92 and 92 are different from the mount center axis M. It has an asymmetric shape. That is, for example, in the longitudinal sectional view shown in FIG. 3, the shapes of the second fluid chambers 92 and 92 are asymmetrical on the left and right with respect to the mount center axis M.

  In the engine mount 10 having such a structure, the inner shaft member 12 is fixed to the power unit by inserting a rod, a bolt, or the like into the center hole 18 of the inner shaft member 12. On the other hand, the outer cylinder member 14 is press-fitted into the mounting hole via a bracket as necessary and fixed to the vehicle body, so that the power unit is elastically supported by the vehicle body by the engine mount 10.

  In the engine mount 10 as described above, the frequency that is the object of vibration isolation of the first orifice passage 94 that connects the pair of first fluid chambers 90 and 90 that face each other in the direction perpendicular to the first axis is the direction perpendicular to the axis. Is tuned to the frequency of the input vibration at. Therefore, when vibration is input in the direction perpendicular to the axis, fluid flow through the first orifice passage 94 accompanying the relative volume change of the first fluid chambers 90, 90 is induced, and the axis is perpendicular to the axis. Anti-vibration effect against the input vibration in the direction is exhibited.

  The second fluid chambers 92, 92 opposed in the direction perpendicular to the second axis have different shapes, and a second orifice passage 96 connecting the second fluid chambers 92, 92 to each other. The frequency that is the object of vibration isolation is tuned to the frequency of the input vibration in the axial direction. Therefore, when vibration is input in the axial direction, fluid flow through the second orifice passage 96 caused by the relative volume change of the second fluid chambers 92, 92 is induced, and the axial direction Anti-vibration effect against input vibration is demonstrated.

  Specifically, in FIG. 3, when the inner shaft member 12 is displaced upward with respect to the outer cylinder member 14, the upper axial wall in the second fluid chamber 92 on the left side in FIG. 3. The portion is a thin-walled portion 60, and the inner surface (the bottom surface of the straight hole 54) is inclined downward toward the outer periphery, so that it is elastically deformed so that tensile deformation is effectively generated. In addition, the lower axial wall portion is a thick wall portion 62, and the inner surface (inclined surface 56) is inclined downward toward the outer periphery, so that it is elastically deformed so as to cause tensile deformation. It is done. Then, both side walls in the axial direction may be thinned along with the tensile deformation. In the second fluid chamber 92 on the left side in FIG. 3, the volume of the second fluid chamber 92 is changed so as to increase, and the negative pressure ( Decompression) occurs.

  In contrast, in the second fluid chamber 92 on the right side in FIG. 3, the upper axial wall portion is a thick wall portion 62 and the inner surface (inclined surface 56) is directed upward toward the outer periphery. By being inclined, it is elastically deformed so as to cause compressive deformation. Further, the lower axial wall portion is a thin portion 60, and the inner surface (the bottom surface of the straight hole 54) is inclined upward toward the outer periphery so that compression deformation can be effectively generated. It can be elastically deformed. Then, both side walls in the axial direction may be thickened along with the compression deformation, and the second fluid chamber 92 on the right side in FIG. (Pressurization) occurs.

  In this way, a volume change (pressure fluctuation) between the pair of second fluid chambers 92 and 92 is relatively generated, thereby inducing a fluid flow through the second orifice passage 96 and an axial input. An anti-vibration effect based on the resonance action of the fluid is exhibited against the vibration.

  In particular, the first fluid chambers 90, 90 for damping input vibration in the direction perpendicular to the axis and the first orifice passage 94 connecting them, and the second fluid chamber 92 for damping input vibration in the axial direction. , 92 and the second orifice passage 96 connecting them are formed separately from each other, so that the resonance frequency in the first orifice passage 94 and the resonance frequency in the second orifice passage 96 are respectively Tuning freedom can be improved. Therefore, both the vibration in the axial direction and the vibration in the direction perpendicular to the axis can be effectively damped.

  In addition, as the end elastic bodies 26 and 26 constituting the axial walls of the first and second fluid chambers 90, 90, 92, 92, different shapes are obtained by using the same shape members by inverting them. An increase in the number of parts is suppressed. Thereby, the cost of equipment for manufacturing parts having different shapes can also be reduced. In addition, when attaching the end elastic bodies 26, 26 to the inner shaft member 12, it is not necessary to distinguish one from the other in the axial direction, so that the assembly workability can be improved.

  Further, as described above, the end elastic bodies 26, 26 are reversed by using the same shape member, so that the axially opposite side of the pair of second fluid chambers 92, 92 is opposite. An inclination direction of the axial wall portion is realized. Thereby, in this embodiment, the elastic deformation in which tensile deformation (compression deformation) is dominant is applied to the axial wall portion (thin wall portion 60) in the second fluid chamber 92 on one side (left side in FIG. 3). At the same time, an elastic deformation in which compression deformation (tensile deformation) is dominant occurs in the axial wall portion (thin wall portion 60) in the second fluid chamber 92 on the other side (right side in FIG. 3). As a result, the volume change between the pair of second fluid chambers 92 and 92 is more effectively induced.

  Furthermore, in the present embodiment, since both the axial walls in the second fluid chamber 92 are the thin portion 60 and the other is the thick portion 62, only the inner surface of the thin portion 60 is provided. In addition, the elastic main shaft is also inclined so as to improve the efficiency of pressure fluctuations in the fluid chamber when axial vibration is input, and the thick portion 62 efficiently ensures the required axial and axial spring characteristics. It is also possible.

  In addition, in the second fluid chamber 92, the inclination direction of the elastic main shaft L1 in the one thin portion 60 in the axial direction (inclination angle with respect to the axial direction) and the inclination direction of the elastic main shaft L2 in the thick portion 62 in the other axial direction. Therefore, the degree of freedom in tuning the spring characteristics in the axial direction and the direction perpendicular to the axial direction, the degree of freedom in setting the pressure generation efficiency, and the like can be further ensured.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the specific descriptions in the embodiments, and various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It is feasible in the form which added.

  For example, the specific structure and tuning mode of the first and second orifice passages are not limited, and the circumferential groove provided on the outer peripheral surface of the main rubber elastic body is covered with the outer cylinder member without using the orifice member. Thus, it is possible to form an orifice passage.

  Furthermore, in the said embodiment, although the 1st fluid chambers 90 and 90 were made into the same shape, it is not limited to this aspect. That is, the shapes of the four fluid chambers formed in the main rubber elastic body may be different from each other.

  Moreover, in the said embodiment, the thin part 60 and 60 which comprises the axial direction both wall part of the 1st fluid chamber 90, and the thin part 60 which comprises one axial direction wall part of the 2nd fluid chamber 92, In all cases, the wall thickness dimension was substantially equal, but the present invention is not limited to such a mode. As described above, the number and shape of the fluid chambers can be appropriately designed and changed in accordance with the required anti-vibration characteristics.

  Further, in the above-described embodiment, the stopper mechanism for buffering the relative displacement amount between the inner shaft member 12 and the outer cylinder member 14 in the direction perpendicular to the axis by the intermediate sleeve 44 facing the stopper protrusion 20 of the inner shaft member 12. However, such a stopper mechanism is not essential.

  Furthermore, in the said embodiment, although the member of the same shape was employ | adopted as the edge part elastic bodies 26 and 26, you may employ | adopt a member of a different shape. The main rubber elastic body preferably has a divided structure, but the main rubber elastic body does not have to be three, and may be composed of two or four or more divided rubber elastic bodies. Moreover, the pocket part which opens on an outer peripheral surface is formed in the axial direction center part of a main body rubber elastic body, and the 1st and 2nd fluid chamber is comprised by covering the opening of this pocket part with an outer cylinder member. It is also possible to adopt an embodiment, and in such an embodiment, the main rubber elastic body can be integrally formed with a single member that is not divided.

  Further, the fluid-filled cylindrical vibration isolator according to the present invention is not limited to the engine mount for automobiles as in the above-described embodiment, but other automobile vibration isolator such as a subframe mount and a body mount. It may be applied to a vibration isolator other than an automobile.

10: Engine mount (fluid-filled cylindrical vibration isolator), 12: Inner shaft member, 14: Outer cylinder member, 16: Main rubber elastic body, 24: Central elastic body (divided rubber elastic body), 26: End Elastic body (divided rubber elastic body), 60: thin-walled portion (axial wall portion), 62: thick-walled portion (axial wall portion), 74: orifice member, 76: first groove (outer peripheral flow path), 78: second groove (outer peripheral flow path), 80: third groove (inner peripheral flow path), 82: fourth groove (inner peripheral flow path), 90: first fluid chamber, 92 : Second fluid chamber, 94: first orifice passage, 96: second orifice passage

Claims (7)

An inner shaft member is disposed through the outer cylinder member, the inner shaft member and the outer cylinder member are connected by a main rubber elastic body, and a fluid chamber in which an incompressible fluid is sealed is provided. In a fluid-filled cylindrical vibration damping device that is provided and exhibits a vibration damping effect based on the flow action of the incompressible fluid,
A pair of first fluid chambers opposed to each other with the inner shaft member sandwiched in a direction perpendicular to the first axis and a first orifice passage communicating the pair of first fluid chambers with each other are provided. On the other hand, the pair of second fluid chambers and the pair of second fluid chambers communicated with each other in a second axis perpendicular direction different from the first axis perpendicular direction with the inner shaft member interposed therebetween. A second orifice passage is formed, and the sealed region of the incompressible fluid in the first fluid chamber and the sealed region of the incompressible fluid in the second fluid chamber are formed independently of each other. And the relative pressure between the pair of second fluid chambers when the axial vibration is input due to the shape of the axial wall portion being different between the pair of second fluid chambers. A fluid-filled cylindrical vibration isolator characterized by fluctuations.   The inner surface of the axial wall part located in at least one of the axial directions in the pair of second fluid chambers is inclined in the opposite direction in the axial direction between the pair of second fluid chambers. The fluid-filled cylindrical vibration isolator described in 1.   The main rubber elastic body is composed of three divided rubber elastic bodies divided into an axial center and both sides, and each axis of the pair of first fluid chambers and the pair of second fluid chambers. The fluid-filled cylindrical vibration damping device according to claim 1 or 2, wherein the same elastic rubber parts divided on both sides in the axial direction constituting the directional wall portion are reversed in the axial direction.   In the pair of second fluid chambers, the thickness dimension of the axial wall portions positioned opposite to each other in the axial direction is equal to the other axial wall portion and the axial wall portion of the pair of first fluid chambers. The fluid-filled cylindrical vibration damping device according to any one of claims 1 to 3, wherein the fluid-filled cylindrical vibration damping device is thicker than any of the above.   The axial direction wall part located in the axial direction both sides in said 2nd fluid chamber WHEREIN: At least one of the thickness direction of an axial direction and an inclination direction is mutually different. The fluid-filled cylindrical vibration isolator as described.   A separate orifice member extending in the circumferential direction is attached to the outer peripheral surface of the main rubber elastic body, and an inner circumferential flow path is provided between the main rubber elastic body and the orifice member, and the orifice member And the outer cylinder member, an outer peripheral flow path is provided, and the first orifice passage and the second orifice passage are formed using the inner peripheral flow path and the outer peripheral flow path. The fluid-filled cylindrical vibration isolator according to any one of claims 1 to 5, which is formed.   The fluid sealing according to claim 6, wherein a pair of the orifice members are provided and arranged to face each other in a direction perpendicular to the axis across the inner shaft member, and the same one is used as the pair of orifice members. Type cylindrical vibration isolator.

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