JP2017172744A - Fluid sealed type cylindrical vibration-proof device - 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 behavior with respect to an axial input vibration while assuring a vibration-proof performance based on a fluid flow behavior with respect to an input vibration in a direction perpendicular to an axis.SOLUTION: A fluid sealed type cylindrical vibration-proof device 10 is configured in such a way that a pair of fluid chambers 104 are oppositely positioned while holding an inner shaft member 12 in a direction perpendicular to an axis, both side walls in an axial direction of a first fluid chamber 104 are configured by a main body rubber elastic body 16, an elastic film 100 is arranged outside in an axial direction of the main body rubber elastic body 16, a second fluid chamber 106 is arranged between the main body rubber elastic body 16 and the elastic film 100 and in turn a first orifice passage 108 for communicating the pair of first fluid chambers 104 to each other and a second orifice passage 110 for communicating the second fluid chamber 106 with at least one of the pair of first fluid chambers 104 are formed to be extended along an outer cylindrical member 14 at an inner peripheral side of the outer cylindrical member 14.SELECTED DRAWING: Figure 2

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 the inner shaft member interposed therebetween are formed in each direction. By communicating with each other through the 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.

  In view of such a problem, in Japanese Patent Laid-Open No. 5-280575 (Patent Document 2), a fluid-filled cylindrical vibration proof that effectively exhibits a vibration proof effect due to fluid flow when axial vibration is input. Devices have also been proposed. Specifically, a flexible membrane is provided on one side in the axial direction of the main rubber elastic body forming the fluid chamber to form an equilibrium chamber, and a partition projection is provided between the fluid chamber and the equilibrium chamber. An axial orifice passage that is constricted and exhibits a vibration isolation effect based on fluid flow action against axial vibration is provided.

  However, in the fluid-filled cylindrical vibration isolator described in Patent Document 2, the degree of freedom of tuning of the axial orifice passage formed by the annular narrow passage is small, and for example, it is difficult to ensure the length of the orifice passage. In some cases, it is difficult to achieve the required anti-vibration characteristics.

  In addition, in the axial orifice passage formed by the annular constricted flow path, the flow resistance tends to be small, and the pressure fluctuation of the fluid chamber easily escapes to the equilibrium chamber when vibration is input in the direction perpendicular to the axis. For this reason, it may be difficult to sufficiently obtain the vibration-proofing effect exhibited based on the fluid flow action against the input vibration in the direction perpendicular to the axis.

JP 2010-159873 A JP-A-5-280575

  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 a fluid-filled cylindrical vibration damping device that is provided with a fluid chamber filled with a compressive fluid and exhibits a vibration damping effect based on the flow action of the incompressible fluid, the inner shaft member is sandwiched in a direction perpendicular to the axis. A pair of first fluid chambers are provided opposite to each other, and both axial side walls of the first fluid chamber are constituted by the main rubber elastic body, and the shaft of the main rubber elastic body An elastic membrane is disposed outward in the direction, and a second fluid chamber is provided between the main rubber elastic body and the elastic membrane, and the pair of first fluid chambers communicate with each other. A first orifice passage and the second fluid chamber at least one of the pair of first fluid chambers; The fluid-filled cylindrical vibration isolator is characterized in that the second orifice passage that communicates is formed so as to extend along the outer cylindrical member on the inner peripheral side of the outer cylindrical member. .

  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 pair of first fluid chambers input vibrations in a direction perpendicular to the axis, a relative pressure fluctuation is positively induced between the pair of first fluid chambers, so that the fluid flows through the first orifice passage. The anti-vibration effect based on the resonance action of the fluid is exerted. Further, at the time of axial vibration input, the relative pressure fluctuation between the first fluid chamber in which the pressure fluctuation is caused and the second fluid chamber in which the pressure fluctuation is reduced or avoided by the elastic membrane is used. The fluid flow through the two orifice passages is generated, and the vibration isolation effect based on the resonance action of the fluid is exhibited.

  In particular, in this aspect, since the first and second orifice passages are provided at the outer peripheral portion having a large peripheral length in the fluid-filled cylindrical vibration isolator, it is possible to ensure a large orifice passage length. Become. As a result, the degree of freedom in frequency tuning of the orifice passage is increased. Further, the passage length of the second orifice passage is ensured as compared with the axial orifice passage configured by the annular narrow passage as described in the above-mentioned cited document 2, so that when the vibration in the direction perpendicular to the axis is input. It is easy to suppress the escape of pressure fluctuation from the first fluid chamber to the second fluid chamber, and it is easy to secure the vibration-proof performance in the direction perpendicular to the axis.

  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 orifice member extending in the circumferential direction inside the outer cylindrical member is provided, and the orifice member is The first orifice passage and the second orifice passage are formed by the orifice member.

  In the fluid-filled cylindrical vibration isolator of this aspect, the orifice passage is formed by using the orifice member, so that the shape of the orifice passage and the cross-sectional area of the orifice passage can be secured stably, based on the fluid flow action. Therefore, it is possible to improve and stabilize the anti-vibration performance. Further, by employing a separate orifice member, the degree of freedom in designing the orifice passage can be improved. The first and second orifice passages need not be formed in the orifice member over the entire length.

  According to a third aspect of the present invention, in the fluid-filled cylindrical vibration damping device according to the first or second aspect, the first orifice passage and the second orifice passage are formed independently of each other. It is what.

  In the fluid-filled cylindrical vibration isolator of this aspect, the tuning of the first orifice passage and the second orifice passage is facilitated, and the tuning accuracy is improved, so that the target vibration isolating performance is more reliable. It becomes possible to get with.

  According to a fourth aspect of the present invention, there is provided a fluid-filled cylindrical vibration isolator according to any one of the first to third aspects, wherein the shaft of the first fluid chamber is formed of the main rubber elastic body. The effective lengths in the direction perpendicular to the axis of the both side walls are different from each other.

  In the fluid-filled cylindrical vibration isolator of this mode, the deformation modes generated at the time of axial vibration input are different from each other on both axial side walls of the first fluid chamber. As a result, the pressure fluctuation in the first fluid chamber can be generated more efficiently, and the amount of fluid flow through the second orifice passage can be increased and the vibration isolation performance associated therewith can be improved.

  According to a fifth aspect of the present invention, there is provided the fluid-filled cylindrical vibration isolator according to the fourth aspect, wherein an intermediate cylindrical member is fixed to an outer peripheral portion of the main rubber elastic body, and the intermediate cylindrical member And the outer cylinder member are fitted and fixed via a seal rubber layer, and a pair of pocket portions opened to the outer peripheral surface of the main rubber elastic body are covered with the outer cylinder member, thereby the pair of the outer cylinder members. The first fluid chamber is formed, while the first and second orifice passages are formed using the space between the intermediate cylinder member and the outer cylinder member, and the intermediate cylinder member The radial dimensions are different from each other on both axial sides of the pair of pocket portions, and between the small diameter portion of the intermediate cylindrical member located on one axial side of the pair of pocket portions and the outer cylindrical member. The second orifice passage is formed; That.

  In the fluid-filled cylindrical vibration isolator of this aspect, the intermediate cylinder member can improve the sealing performance for the external space of the fluid-filled region including each fluid chamber and the orifice passage. Moreover, by providing a small diameter portion in the intermediate cylindrical member, while realizing a configuration in which the effective length in the direction perpendicular to the axis of the one wall portion in the axial direction of the first fluid chamber according to the fourth aspect is reduced, It is possible to efficiently secure a region where the second orifice passage is formed between the small diameter portion and the outer cylindrical member. The first and second orifice passages do not need to be formed between the intermediate cylinder member and the outer cylinder member in the entire length.

  A sixth aspect of the present invention is a fluid-filled cylindrical vibration isolator according to any one of the first to fifth aspects, wherein at least one of the first orifice passage and the second orifice passage. In the above, there is provided a switching valve for switching the communication state by utilizing the pressure fluctuation of the incompressible fluid caused by the input vibration.

  In the fluid-filled cylindrical vibration isolator of this aspect, the communication state of the first and / or second orifice passages by the switching valve can be controlled. The fluid flow amount in the second orifice passage is increased by restricting the fluid flow amount in the orifice passage, and the fluid flow amount in the second orifice passage at the time of vibration input in the direction perpendicular to the axis is restricted. It is possible to increase the amount of fluid flow in the orifice passage and to further improve the target vibration isolation performance.

  In the fluid-filled cylindrical vibration isolator constructed according to the present invention, the vibration isolating effect is exhibited by the first orifice passage communicating with the pair of first fluid chambers against the input vibration in the direction perpendicular to the axis. The anti-vibration effect is exerted by the second orifice passage communicating the first fluid chamber and the second fluid chamber against the axial input vibration. Here, since both the first orifice passage and the second orifice passage are formed so as to extend on the inner peripheral side of the outer cylinder member, each passage length can be efficiently secured. The degree of freedom in design can be improved, and it is possible to obtain excellent vibration isolation performance in the axial direction while securing vibration isolation performance in the direction perpendicular to the axis.

It is a longitudinal cross-sectional view which shows the fluid enclosure type | formula vibration isolator as one Embodiment of this invention, Comprising: II sectional drawing in FIG. It is another longitudinal cross-sectional view of the fluid-filled cylindrical vibration isolator shown in FIG. 1, and is a II-II cross-sectional view in FIG. III-III sectional drawing in FIG. The perspective view which shows the main body rubber elastic body which comprises the fluid enclosure type | formula vibration isolator shown by FIG. 1 in the state of integral vulcanization molding products. The perspective view which shows the 1st orifice member which comprises the fluid filling type | mold cylindrical vibration isolator shown by FIG. The perspective view from another direction which shows the 1st orifice member shown by FIG. The perspective view which shows the 2nd orifice member which comprises the fluid filling type | mold cylindrical vibration isolator shown by FIG. The perspective view from another direction which shows the 2nd orifice member shown by FIG. The perspective view which shows a specific example of the switching valve which can be employ | adopted for the fluid filling type | mold cylindrical vibration isolator which concerns on this invention. The longitudinal cross-sectional view for demonstrating the state which mounted | wore the orifice member with the switching valve shown by FIG. The perspective view which shows another specific example of the switching valve which can be employ | adopted for the fluid filling type | mold cylindrical vibration isolator which concerns on this invention. The longitudinal cross-sectional view for demonstrating the state which mounted | wore the orifice member with the switching valve shown by FIG.

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

  First, FIGS. 1 to 3 show an automobile engine mount 10 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 vertical direction in FIG. 1 that is the mount central axis direction. Further, the upper side means the upper side in FIG. 1, while the lower side means the lower side in FIG. Furthermore, the direction perpendicular to the axis is a direction orthogonal to the mount center axis, and refers to, for example, the left-right direction in FIGS.

  More specifically, the inner shaft member 12 is a relatively thick and small-diameter cylindrical member, and is formed of a metal such as iron or an aluminum alloy, or a hard synthetic resin. A central hole 18 penetrating in the axial direction is formed in the center of the inner shaft member 12.

  On the other hand, the outer cylinder member 14 is formed as a substantially cylindrical member that is thinner and larger in diameter than the inner shaft member 12 as a whole, and is formed of the same material as the inner shaft member 12. In addition, an inner flange portion 20 is formed at the upper end portion of the outer cylinder member 14 so as to bend toward the inner peripheral side over the entire circumference and protrude in the radial direction. Further, a locking portion 22 is formed at the lower end portion of the outer cylinder member 14 by being bent so as to incline to the inner peripheral side over the entire circumference. Further, a thin seal rubber layer 24 is fixed to the inner surface of the outer cylinder member 14 over the entire surface.

  The inner shaft member 12 and the outer cylinder member 14 are disposed substantially coaxially, and the inner shaft member 12 is inserted through the outer cylinder member 14. Here, the axial dimension of the outer cylinder member 14 is shorter than that of the inner shaft member 12, and the inner shaft member 12 projects 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. 4, the main rubber elastic body 16 has a relatively thick, generally cylindrical shape as a whole, and the inner shaft member 12 is inserted into the central hole 26 so that the inner shaft A main rubber elastic body 16 is vulcanized and bonded to the outer peripheral surface of the member 12.

  Further, both end surfaces in the axial direction of the main rubber elastic body 16 are curved concave surfaces in which a radial intermediate portion is recessed. Further, on both end surfaces in the axial direction, paired rake holes 28 and 30 are formed on both sides of the inner shaft member 12 in one direction perpendicular to the axis (vertical direction in FIG. 3). ing.

  Furthermore, a pair of pocket portions 32 a and 32 b that open to the outer peripheral surface are formed in the axially intermediate portion of the main rubber elastic body 16. These pocket portions 32a and 32b are provided on both sides in the direction perpendicular to the axis (left and right direction in FIG. 3) with the inner shaft member 12 interposed therebetween. Further, these pocket portions 32a and 32b have substantially constant width dimensions (axial dimensions) and are each formed with a circumferential dimension length less than a half circumference.

  In this embodiment, the static or dynamic input load in the direction perpendicular to the axis is taken into consideration, and the circumferential dimension of the pocket portion 32a on one side (left side in FIG. 3) is the other (right side in FIG. 3). )) Is smaller than the circumferential dimension of the pocket portion 32b. And a pair of arm parts 34 and 34 formed between the circumferential directions of the pocket parts 32a and 32b are inclined to one side (left side in FIG. 3) perpendicular to the axis from the inner shaft member 12 toward the outer circumference. ing.

  Further, connection grooves 36 and 36 are formed on the outer peripheral surfaces of these arm portions 34 and 34, that is, on the outer peripheral surface of the main rubber elastic body 16, where the pocket portions 32a and 32b are not provided. These connection grooves 36 and 36 are bent in a crank shape, and the openings of the pair of pocket portions 32a and 32b communicate with each other.

  Further, in the main rubber elastic body 16, the portions constituting the axial side walls of the pocket portions 32 a and 32 b are annular wall portions 38 and 38 that continuously spread in the circumferential direction. Further, axial communication grooves 40, 40 extending from the central portion in the axial direction onto the outer peripheral surface of one annular wall 38 are formed on the outer peripheral surfaces of the arm portions 34, 34.

  Further, by providing the communication grooves 40, 40, the radial width dimension is partially different in the circumferential direction in one annular wall portion 38. That is, the radial width dimension of the annular wall portion 38 where the communication groove 40 is provided, compared to the radial width dimension α (see FIG. 1) of the annular wall portion 38 where the communication groove 40 is not provided. β (see FIG. 1) is reduced by the depth of the communication groove 40.

  Further, an intermediate cylinder fitting 42 as an intermediate cylinder member is fixed to the outer peripheral portion of the main rubber elastic body 16. A seal rubber layer 44 having a predetermined thickness is formed on the outer peripheral surface of the intermediate tube fitting 42 by the main rubber elastic body 16. Further, the intermediate cylindrical fitting 42 is provided with a step 45 near the other end in the axial direction (lower in FIGS. 1 and 2), and the other side in the axial direction across the step 45 is the large diameter portion 42a. In addition, one side in the axial direction is a small diameter portion 42b. As a result, the large-diameter portion 42a is positioned on the outer peripheral portion of the other annular wall portion 38 in the axial direction, and the small-diameter portion 42b is positioned on the outer peripheral portions of the one annular wall portion 38 and the arm portions 34, 34 in the axial direction. ing.

  The outer diameter radius dimension of the small diameter portion 42b is substantially equal to the radial width dimension from the center axis of the inner shaft member 12 to the groove bottom surface of the communication groove 40, and the outer diameter dimension of the large diameter portion 42a is annular. The outer diameter of the wall portion 38 is substantially equal. That is, the large diameter portion 42a and the small diameter portion 42b have different thicknesses of the seal rubber layer 44 provided on the outer peripheral side, and the seal rubber layer 44 provided on the outer peripheral side of the large diameter portion 42a is thin. On the other hand, the seal rubber layer 44 provided on the outer peripheral side of the small diameter portion 42b is thick.

  Here, since the seal rubber layer 44 on the outer peripheral side of the intermediate cylindrical metal member 42 is not substantially elastically deformed, the upper and lower annular wall portions 38 and 38 have shafts of the main rubber elastic body 16 constituting them. The effective lengths in the perpendicular direction are different. In short, the effective length L1 (see FIG. 2) of the main rubber elastic body 16 constituting the lower annular wall portion 38 where the large-diameter portion 42a of the intermediate tubular fitting 42 is located is the upper annular wall where the small-diameter portion 42b is located. The effective length L2 (see FIG. 2) of the main rubber elastic body 16 constituting the portion 38 is made larger.

  In addition, a pair of opening windows 46a and 46b are formed in the small-diameter portion located in the center portion in the axial direction of the intermediate cylindrical fitting 42, and the pocket portions 32a and 32b are opened to the outer periphery through these opening windows 46a and 46b. Yes.

  And among the small diameter part 42b of the intermediate | middle cylinder metal fitting 42, the surrounding wall part which spreads between the circumferential direction both ends of pocket part 32a, 32b is respectively the circumferential direction both ends of the orifice members 52 and 54 mentioned later in a circumferential direction both ends part, respectively. It comes to support. Further, the communication grooves 40 and 40 described above are formed in the peripheral wall portion supporting the orifice members 52 and 54 with respect to the thick portion of the seal rubber layer 44 deposited on the outer peripheral surface. .

  In the present embodiment, as shown in FIG. 4, the main rubber elastic body 16 having the structure as described above is formed as an integrally vulcanized molded product 48 including the inner shaft member 12 and the intermediate cylinder fitting 42. ing.

  An orifice member 50 is fitted into each of the pocket portions 32a and 32b of the main rubber elastic body 16. The orifice member 50 includes a first orifice member 52 shown in FIGS. 5 and 6 and a second orifice member 54 shown in FIGS.

  The first and second orifice members 52 and 54 as a whole have a curved plate shape that curves and extends in the circumferential direction, and are formed of metal or hard synthetic resin. The first orifice member 52 is formed with a circumferential length that can cover the opening portion of the other pocket portion 32b, while the second orifice member 54 covers the opening portion of the one pocket portion 32a. It is formed with a circumferential length that can be covered. The width dimensions of the first and second orifice members 52, 54 are substantially the same as the groove width dimensions at the opening portions of the pocket portions 32b, 32a.

  On the outer peripheral surface of the first orifice member 52, a first outer peripheral groove 56 formed of a single continuous groove is formed meandering. In addition, 57 in FIG. 5 is a meat hollow. One end portion in the length direction of the first outer circumferential groove 56 is located at the approximate center of the first orifice member 52, and is opened to the inner circumferential surface through a through hole 58 provided in the bottom wall. . The other end of the first outer circumferential groove 56 is open to one end surface in the circumferential direction of the first orifice member 52. In the present embodiment, the length of the circumference of the first orifice member 52 is at least twice as long as the meandering first outer circumferential groove 56.

  A second outer circumferential groove 72 formed of a single continuous groove is formed on the outer circumferential surface of the second orifice member 54. The second outer circumferential groove 72 has one end in the length direction opened to the end surfaces on both sides in the circumferential direction of the second orifice member 54. Moreover, the intermediate part of the length direction of the 2nd outer periphery groove | channel 72 is opened by the inner peripheral surface through the through-hole 76 provided in the bottom wall.

  In the present embodiment, the length of the circumference of the second orifice member 54 is at least twice as long as the meandering second outer circumferential groove 72. Then, the second outer circumferential groove 72 includes two concave grooves, a concave groove 78 extending from the through hole 76 to the opening at one peripheral end and a concave groove 80 extending from the through hole 76 to the opening at the other peripheral end. Is formed. Further, since the through hole 76 is formed at the center in the length direction of the second outer circumferential groove 72, the two concave grooves 78 and 80 have substantially the same length. In addition, a notch 74 is formed in the side wall of the opening portion at the peripheral end of the one concave groove 80, and is opened from the circumferential end surface of the second orifice member 54 to the side wall.

  Further, an elastic film 100 is provided on the outer side of the main rubber elastic body 16 in the axial direction (upward in FIG. 1). The elastic film 100 is a substantially annular member formed of rubber or elastomer, and spreads in a direction perpendicular to the axis. The elastic film 100 can be bent and deformed by being sufficiently thin. In particular, in this embodiment, it is a curved slack shape, and outward bulging deformation and the like are easy.

  A cylindrical fitting 102 is fixed to the inner peripheral side of the elastic film 100, while the outer peripheral side of the elastic film 100 is fixed to the inner flange portion 20 of the outer cylindrical member 14. In the present embodiment, the elastic film 100 and the seal rubber layer 24 provided on the inner peripheral surface of the outer cylinder member 14 are integrally formed, and the elastic film 100 (the seal rubber layer 24) is formed between the fitting fitting 102 and the outer cylinder. It is formed as an integrally vulcanized molded product including the member 14.

  The second orifice member 54 and the first orifice member 52 are fitted into the pocket portions 32a and 32b of the main rubber elastic body 16 having the structure as described above, and the elastic membrane 100 is formed from the outside of these assemblies. The engine mount 10 of the present embodiment is configured by assembling the outer cylinder member 14 provided.

  That is, the second orifice member 54 and the first orifice member 52 are fitted into the pocket portions 32a and 32b of the main rubber elastic body 16 and covered with the outer cylindrical member 14, thereby opening the pocket portions 32a and 32b. The part is covered. Thus, a pair of first fluid chambers 104, 104 are formed facing each other in the direction perpendicular to the axis with the inner shaft member 12 interposed therebetween. Further, both axial wall portions of the pair of first fluid chambers 104, 104 are constituted by a pair of upper and lower annular wall portions 38, 38.

  Further, the elastic film 100 is disposed on one side of the main rubber elastic body 16 in the axial direction, and the fitting 102 is fitted and fixed to the inner shaft member 12, so that the main rubber elastic body 16, the elastic film 100, In between, a substantially annular second fluid chamber 106 is formed as a whole.

  In the present embodiment, the gap 107 extends over the entire circumference between the thick seal rubber layer 44 and the inner seal rubber layer 24 of the outer cylinder member 14 at the end on the small diameter portion 42b side of the intermediate tube fitting 42. The gap 107 ensures a sufficient cross-sectional area of the communication channel 40 from the communication groove 40 to the second fluid chamber 106.

  In addition, after the outer cylinder member 14 is assembled to the main rubber elastic body 16 by extrapolation, the outer cylinder member 14 is subjected to diameter reduction processing, so that the outer cylinder member 14 is intermediated via the seal rubber layers 24 and 44. The tube fitting 42 is fixed in a fluid tight manner. Thereby, the first and second fluid chambers 104, 104, 106 and first and second orifice passages 108, 110 described later are formed in a liquid-tight manner.

  When the outer cylinder member 14 is assembled to the main rubber elastic body 16, the lower end of the outer cylinder member 14 is straight, but is bent to the inner peripheral side by caulking after assembly. Thereby, the axial latching | locking part 22 with respect to the intermediate | middle cylinder metal fitting 42 is formed.

  The first and second fluid chambers 104, 104, 106 are filled with incompressible fluid. The incompressible fluid to be encapsulated is not limited at all, 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.

  Further, the assembly of the main rubber elastic body 16 such as the integrally vulcanized molded article 48 and the outer cylindrical member 14 is performed in an incompressible fluid, whereby the first and second fluid chambers 104, 104, 106 are attached. It is easy to enclose the incompressible fluid.

  Here, the opening of the first outer peripheral groove 56 provided on the outer peripheral side of the first orifice member 52 and the second outer peripheral groove 72 provided on the outer peripheral side of the second orifice member 54, the intermediate cylinder fitting 42. The openings of the connection grooves 36 and the communication grooves 40 provided on the outer peripheral side of the cover are covered with the outer cylindrical member 14 via the seal rubber layer 24, whereby a tunnel-like flow path is formed. A first orifice passage 108 that connects the pair of first fluid chambers 104 and 104 to each other is formed, and the first fluid chamber 104 and the second fluid passage 104 (on the left side in FIG. 2) are connected to each other. A second orifice passage 110 communicating with the fluid chamber 106 is formed.

  That is, the first orifice passage 108 that communicates the pair of first fluid chambers 104 and 104 with each other includes the through hole 76, one concave groove 78 in the second outer peripheral groove 72, the connection groove 36, and the first outer periphery. The groove 56 and the through hole 58 are configured.

  Further, the second orifice passage 110 that communicates one of the first fluid chamber 104 and the second fluid chamber 106 with each other includes the through hole 76, the other outer peripheral groove 80 in the second outer peripheral groove 72, and the communication groove. 40 and a gap 107.

  Accordingly, the first and second orifice passages 108 and 110 are formed between the main rubber elastic body 16 and the first and second orifice members 52 and 54 and the outer cylindrical member 14, and these first and second orifice passages 108 and 110 are formed. Two orifice passages 108 and 110 are formed along the outer cylinder member 14 on the inner peripheral side of the outer cylinder member 14. In particular, the first and second orifice passages 108 and 110 have a common through hole 76 that is one end in the length direction, but the intermediate portion in the length direction and the other end are formed separately. And are formed substantially independently of each other.

  The orifice passages 108 and 110 are adjusted by adjusting the ratio (A / L) of the passage sectional area (A) and the passage length (L) of the first orifice passage 108 and the second orifice passage 110. The frequency to be subjected to vibration isolation can be made different. In the present embodiment, the frequency that is the object of vibration isolation of the first orifice passage 108 is tuned to the frequency of the input vibration in the direction perpendicular to the axis, while the frequency of the object of vibration isolation of the second orifice passage 110 is Tuned to the frequency of the input vibration in the axial direction.

  In the engine mount 10 having the above-described structure, the bolt is inserted into the center hole 18 of the inner shaft member 12 so that the power unit is attached to the inner shaft member 12, and the outer cylinder member 14 is connected to the vehicle body via the bracket. Attached to. As a result, the power unit is supported by the engine mount 10 in a vibration-proof manner with respect to the vehicle body.

  In the engine mount 10, when a vibration in a direction perpendicular to the axis is input, a relative pressure change and, therefore, a volume change occurs between the pair of first fluid chambers 104, 104. Then, fluid flow through the first orifice passage 108 is induced, and an anti-vibration effect is exhibited.

  On the other hand, when an axial vibration is input, a relative pressure change and, therefore, a volume change occurs between the first fluid chamber 104 and the second fluid chamber 106. Then, the fluid flow through the second orifice passage 110 is induced, and the anti-vibration effect is exhibited.

  In particular, the first orifice passage 108 and the second orifice passage 110 are formed so as to extend along the outer cylinder member 14 on the inner peripheral side of the outer cylinder member 14. The passage length is sufficiently secured, and the degree of freedom in tuning the resonance frequency in both passages 108 and 110 can be improved. Therefore, it can be appropriately tuned by the frequency of the input vibration in the axial direction and the direction perpendicular to the axis to be anti-vibration, improving the anti-vibration effect, and one vibration input in the axial direction and the direction perpendicular to the axis. Sometimes pressure can be effectively prevented from escaping to the other.

  In addition, since the first and second orifice passages 108 and 110 are formed using the first and second orifice members 52 and 54 which are separated from each other, the passage shape can be easily designed. Therefore, the degree of freedom in tuning can be further improved. In addition, since the first and second orifice passages 108 and 110 are formed independently of each other, the degree of freedom in tuning can be further improved.

  Furthermore, in the present embodiment, the intermediate cylindrical fitting 42 is provided with the large diameter portion 42a and the small diameter portion 42b, so that the upper and lower annular wall portions 38, which constitute both axial walls of the first fluid chambers 104, 104, 38, the effective lengths L2 and L1 in the radial direction of the main rubber elastic body 16 are different. Therefore, when the vibration is input in the axial direction, the first fluid chambers 104 and 104 are different from each other in the deformation mode of the both axial walls. A change in pressure relative to the fluid chamber 106 is more effectively generated. As a result, a large amount of fluid flow through the second orifice passage 110 is ensured, and the anti-vibration effect in the axial direction is more stably exhibited.

  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, at least one of the first orifice passage 108 and the second orifice passage 110 has a switching valve for switching the communication state of the respective orifice passages 108 and 110 due to the pressure fluctuation of the incompressible fluid caused by the input vibration. A control valve or the like that selectively restricts the amount of fluid flow may be provided.

  Specifically, for example, as shown in FIGS. 9 and 10, a valve body 112 is provided in the first or second orifice member 52 or 54, and the first or second orifice passages 108 and 110 communicate with each other. It is also possible to switch the state. The valve body 112 has a valve spring 112 a supported by a leaf spring 112 a fixed to the first or second orifice member 52, 54, and is opposed to the inner peripheral side opening portions of the through holes 58 and 76. It has come to be. When a large fluid pressure is applied, the valve seal 112b is displaced and pressed in a direction approaching the inner peripheral surface of the orifice members 52 and 54, thereby narrowing the first or second orifice passages 108 and 110. Or shut off.

  Further, for example, a valve body 114 as shown in FIGS. 11 and 12 may be employed. The valve body 114 includes large and small elastic pieces 116a and 116b that protrude in the fluid flow direction on both side wall portions that form the fluid flow path, in a state of facing each other. When a large fluid pressure is applied, the first or second orifice passages 108 and 110 are narrowed by the large elastic piece 116a being elastically deformed and brought into contact with the small elastic piece 116b. Or shut off.

  Therefore, if such valve bodies 112 and 114 are employed, it is possible to control the amount of fluid flow in the first and / or second orifice passages 108 and 110. Therefore, for example, at the time of vibration input in a direction perpendicular to the axis, the second orifice passage 110 is connected to the valve body 112 by utilizing the fact that the relative pressure fluctuation induced between the pair of first fluid chambers 104 and 104 is large. , 114, 114 restricts the pressure and fluid escape from the first fluid chamber 104 to the second fluid chamber 106, thereby ensuring a more advantageous fluid flow amount through the first orifice passage 108. By doing so, it is possible to further improve the vibration isolation performance. On the other hand, when the vibration is input in the axial direction, since the relative pressure fluctuation generated between the first fluid chamber 104 and the second fluid chamber 106 is relatively small, the valve bodies 112 and 114 are brought into a communication state. In addition, it is possible to easily allow fluid flow through the second orifice passage 110 so that the desired vibration isolation performance is exhibited.

  However, the specific structure and operation mode of the valve body are not limited. 9 to 12 are exemplary reference views, and do not limit the orifice member to which the valve bodies 112 and 114 are attached.

  Further, the orifice member need not be composed of two members, the first orifice member 52 and the second orifice member 54 as in the above-described embodiment. That is, it may be composed of a cylindrical member extending continuously over the entire circumference, or may be composed of three or more members.

  However, the orifice member is not indispensable, and the first or second is formed by providing a concave groove that opens to the outer peripheral side on the outer peripheral surface of the main rubber elastic body, and covering the opening of the concave groove with the outer cylindrical member. At least one of the two orifice passages may be formed.

  Furthermore, in the said embodiment, one 1st fluid chamber 104 and the 2nd fluid chamber 106 were mutually connected by the 2nd orifice channel | path 110, For example, providing a pair of 2nd orifice channel | paths, Each of the pair of first fluid chambers may be communicated with the second fluid chamber by a separate second orifice passage.

  Furthermore, in the above-described embodiment, the second fluid chamber 106 is continuously formed over the entire circumference in the circumferential direction. For example, the second fluid chamber 106 is divided in the circumferential direction so that one second fluid chamber and the other fluid chamber 106 are separated. A second fluid chamber may be formed. In such a case, one second fluid chamber and one first fluid chamber can communicate with each other, and the other second fluid chamber and the other second fluid chamber can communicate with each other. That is, a total of four fluid chambers may be formed. However, the number and shape of the fluid chambers are not limited, and can be appropriately designed and changed according to required vibration isolation characteristics.

  In the above embodiment, an automotive engine mount is exemplified as the fluid-filled cylindrical vibration isolator according to the present invention. However, the present invention is not limited to the automotive engine mount. The present invention can be applied to other vibration isolator for a vehicle such as a body mount, or can be applied to a vibration isolator other than a vehicle.

10: Engine mount (fluid-filled cylindrical vibration isolator), 12: Inner shaft member, 14: Outer cylinder member, 16: Main rubber elastic body, 24, 44: Seal rubber layer, 32a, 32b: Pocket part, 42: Intermediate cylinder fitting (intermediate cylinder member), 42b: small diameter portion, 50: orifice member, 52: first orifice member, 54: second orifice member, 100: elastic membrane, 104: first fluid chamber, 106: Second fluid chamber, 108: first orifice passage, 110: second orifice passage, 112, 114: valve body

Claims (6)

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 are provided so as to face each other with the inner shaft member sandwiched in a direction perpendicular to the axis, and both side walls in the axial direction of the first fluid chamber are constituted by the main rubber elastic body. And an elastic film is disposed axially outward of the main rubber elastic body, and a second fluid chamber is provided between the main rubber elastic body and the elastic film. A first orifice passage that communicates the first fluid chamber with each other and a second orifice passage that communicates the second fluid chamber with at least one of the pair of first fluid chambers are formed on the outer cylinder member. A fluid-filled cylindrical vibration isolator having an inner peripheral side extending along the outer cylinder member.   An orifice member extending in the circumferential direction inside the outer cylinder member is provided, and the orifice member is disposed on an outer peripheral portion of the pair of first fluid chambers, and the orifice member is connected to the first orifice passage. The fluid-filled cylindrical vibration damping device according to claim 1, wherein the second orifice passage is formed.   The fluid-filled cylindrical vibration isolator according to claim 1 or 2, wherein the first orifice passage and the second orifice passage are formed independently of each other.   The fluid-filled type according to any one of claims 1 to 3, wherein effective lengths in the direction perpendicular to the axis of the both side walls in the axial direction of the first fluid chamber made of the main rubber elastic body are different from each other. Cylindrical vibration isolator. An intermediate cylindrical member is fixed to the outer peripheral portion of the main rubber elastic body, and the intermediate cylindrical member and the outer cylindrical member are fitted and fixed via a seal rubber layer, and opened to the outer peripheral surface of the main rubber elastic body. The pair of first fluid chambers are formed by covering the pair of pocket portions provided by the outer cylinder member,
The first and second orifice passages are formed using a space between the intermediate cylinder member and the outer cylinder member,
The diameter of the intermediate cylinder member is different from each other on both axial sides of the pair of pocket portions, and the small diameter portion and the outer cylinder in the intermediate cylinder member located on one axial side of the pair of pocket portions The fluid-filled cylindrical vibration isolator according to claim 4, wherein the second orifice passage is formed between the member and the member.   The switching valve for switching a communication state by using pressure fluctuation of the incompressible fluid caused by input vibration is provided in at least one of the first orifice passage and the second orifice passage. The fluid-filled cylindrical vibration isolator according to any one of 1 to 5.

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