JP2007032745A - Fluid-filled vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid-filled vibration isolator of a new structure, capable of achieving sufficient withstand load performance against input vibration without enlarging a device as a whole, obtaining a sufficient contact area of a rebound contact portion, having high reliability and exercising an effective stopper function. <P>SOLUTION: A first mounting member 12 is constituted by assembling an inner shaft body 20 comprising a step portion 82 and a stopper member 22 comprising a contact portion 100 in a state of being kept into contact with each other at the step portion 82, the contact portion 100 formed on the first mounting member 12 is axially opposite to a contacted portion 76 formed on a cylindrical bracket 18 fixed to a second mounting member 14, and the contacting portion 100 and the contacted portion 76 are kept into contact with each other through a cushion rubber 106, thus a rebound stopper mechanism limiting relative displacement of the first mounting member 12 and the second mounting member 14 is constituted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a fluid chamber in which a part of the wall portion is formed of a main rubber elastic body that couples a first mounting member and a second mounting member, and prevents fluid based on the fluid flow action in the fluid chamber. More particularly, the present invention relates to a fluid-filled vibration isolator equipped with a stopper mechanism that limits the amount of deformation of a main rubber elastic body when an excessive load is input.

  Conventionally, as a vibration isolator as an anti-vibration coupling body or an anti-vibration support body interposed between members constituting a vibration transmission system and exhibiting an anti-vibration effect, a fluid chamber enclosing an incompressible fluid has been provided. A fluid-filled vibration isolator provided is known. In such an anti-vibration device, an excellent anti-vibration effect can be obtained by a fluid action such as a resonance action of an incompressible fluid sealed in a fluid chamber. It is being considered.

  As one of the fluid-filled vibration isolator, a first mounting member as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2003-232397) is used as a second mounting member having a cylindrical shape. The first mounting member and the second mounting member are axially perpendicular to each other by a main rubber elastic body while being inserted into the axial direction on the central axis from one opening in the axial direction and spaced by a predetermined distance in the direction perpendicular to the axis. Some have a structure connected in the direction.

  In such a vibration isolator, one opening in the axial direction of the second mounting member is fluid-tightly closed with the main rubber elastic body, and the other opening is fluid-tightly closed with a flexible film. A fluid chamber is formed between the opposing surfaces of the main rubber elastic body and the flexible membrane on the inner peripheral side of the second mounting member. Further, the fluid chamber is partitioned by a partition member supported by the second mounting member, and a pressure receiving chamber in which a part of the wall portion is formed of the main rubber elastic body on both sides of the partition member. In addition, equilibrium chambers in which a part of the wall portion is formed of the flexible film are formed. Further, the pressure receiving chamber and the equilibrium chamber are communicated with each other through an orifice passage.

  By the way, the vibration isolator generally has a stopper mechanism in order to suppress an excessive displacement of the power unit that supports the image stabilization with respect to the vehicle body when an excessive external force is input. In this stopper mechanism, the stopper contact portions provided on the first mounting member and the second mounting member are brought into contact with each other via a buffer rubber, so that the relative displacement amount of both mounting members is limited in a buffering manner. Thus, the elastic deformation amount of the main rubber elastic body is regulated.

  However, in the case of the fluid-filled vibration isolator having the above-described structure, the first mounting member protrudes from the opening on one side in the axial direction of the second mounting member. In such a structure, it is difficult to provide a rebound stopper mechanism in the extraction direction which is one side of the first mounting member in the axial direction.

  In order to solve such a problem, Patent Document 2 (Japanese Utility Model Publication No. 6-33228) discloses that the first mounting member protrudes outward in the direction perpendicular to the axial direction with respect to the axial protruding portion from the elastic body. The stopper bracket (stopper arm) that spreads out is fixed, while the second mounting member has a contact bracket (lip) that protrudes inwardly in the direction perpendicular to the axis at the opening on one side in the axial direction. By disposing these stopper brackets and abutment brackets so as to oppose each other in the axial direction, a fluid-filled type anti-shock that has a stopper mechanism in the rebound direction (axial direction opposite to the direction in which the power unit load acts) is constructed. A shaker is shown.

  However, the fluid-filled vibration isolator provided with the stopper mechanism having such a structure still has a problem, and is not sufficiently practical. That is, in such a fluid-filled vibration isolator, since the central portion in the direction perpendicular to the axis of the stopper fitting is overlapped and fixed in the axial direction with respect to the first mounting member, the axis of the overlapping surface is fixed. If the area in the direction projection is not sufficiently large, it is difficult to ensure sufficient load resistance in the bound direction, which is the axial direction opposite to the rebound direction. In addition, in order to obtain sufficient load resistance in the bound direction, if the area of the overlapping surface of the stopper fitting and the first mounting member is sufficiently wide, the length of the stopper arm that extends outward in the direction perpendicular to the axis is increased. It is difficult to obtain sufficiently, and the size of the stopper rubber that is fixed to the tip of the stopper bracket is reduced. Therefore, the contact area between the stopper bracket and the stopper bracket via the stopper rubber is reduced, resulting in stress concentration. Insufficient load resistance in the rebound direction, such as damage to stopper rubber, stopper metal fittings, contact metal fittings, etc., may become a problem. Furthermore, in order to obtain a sufficiently long stopper arm while ensuring a sufficient area of the overlapping surface of the abutment metal fitting and the first attachment metal fitting, the second attachment is required at least at the location where the stopper mechanism is disposed. Although it is necessary to increase the diameter of the member, it is difficult to say that it is practical in a vibration isolator having a limited installation space because it may directly increase the size of the entire apparatus.

  In addition, in the structure in which a separate abutment fitting is fitted to the second mounting bracket, when the stopper fitting is strongly pressed against the abutment fitting when shocking vibration is input, etc. It is difficult to realize high reliability because there is a possibility that the contact metal fitting may come off from the second mounting member or that the contact metal fitting itself may suffer from problems such as deformation.

JP 2003-232397 A Japanese Utility Model Publication No. 6-33228

  Here, the present invention has been made in the background as described above, and the problem to be solved is to realize a sufficient load resistance performance against input vibration without causing a significant increase in the size of the entire apparatus. Another object of the present invention is to provide a fluid-filled vibration isolator having a novel structure capable of sufficiently obtaining the contact area of the rebound contact portion and exhibiting an effective stopper function with high reliability.

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

  That is, according to the first aspect of the present invention, the first mounting member is inserted in the axial direction on the central axis from one axial opening of the second mounting member having a cylindrical shape, and predetermined in the direction perpendicular to the axis. The first mounting member and the second mounting member are connected to each other in the direction perpendicular to the axis by a main rubber elastic body, while the other opening in the axial direction of the second mounting member is allowed. A first fluid that is fluid-tightly closed by a flexible membrane and in which an incompressible fluid is sealed between the opposing surface of the main rubber elastic body and the flexible membrane on the inner peripheral side of the second mounting member A pressure receiving chamber in which the first fluid chamber is partitioned by a partition member supported by the second mounting member and a part of the wall portion is configured by the main rubber elastic body, and a wall portion Are formed on both sides of the partition member, and the pressure receiving chamber and the equilibrium chamber are mutually connected. In the fluid-filled vibration isolator having a first orifice passage therethrough, the first attachment member includes an inner shaft body fixed to the main rubber elastic body and a stopper member attached to the inner shaft body. The inner shaft body is formed with a stepped portion at a part in the middle in the axial direction, and one side in the axial direction is a press-fitting portion across the stepped portion, and the other side in the axial direction is the The fixing portion has a diameter larger than that of the press-fitting portion. The press-fitting portion protrudes from the main rubber elastic body toward one side in the axial direction, and is formed on the outer peripheral surface of the fixing portion. While the main rubber elastic body is vulcanized and bonded, the stopper member is formed with a press-fit recess that opens to the end surface on the other side in the axial direction, and the press-fit portion is pivoted to the press-fit recess. The bottom end of the stopper member. The inner shaft body and the stopper member are positioned and fixed to each other so that the first mounting member is constituted by at least a part of the inner shaft body being overlapped and brought into contact with the stepped portion. A contact portion that extends in a direction perpendicular to the axis is formed at the opening edge of the recess, and the contact portion that is formed on the cylindrical bracket that is attached to the second attachment member in an extrapolated state corresponds to the contact portion. And the shock absorbing rubber is fixed to at least one of the contact part and the contacted part, and the contact part and the contacted part are based on the buffer contact. And a rebound stopper mechanism configured to limit a relative displacement amount of the first mounting member in the axial extraction direction with respect to the second mounting member.

  In the fluid-filled vibration isolator having the structure according to this aspect, the main rubber fixing member is provided with a step portion, and the lower end surface of the stopper member (the end surface on the opening side of the press-fitting recess) with respect to the step portion. ) In the axial direction advantageously secures the extension dimension (projected area in the axial direction of the contact portion) of the contact portion in the direction perpendicular to the axis without increasing the overall size of the vibration isolator. I can do it. Therefore, the contact area between the contact portion and the contacted portion can be advantageously obtained, and a rebound stopper mechanism having excellent load resistance performance in the rebound direction due to stress dispersion or the like can be realized. In addition, since the overlapping area in the axial projection between the stopper member and the main rubber fixing member can be advantageously ensured, a rebound stopper mechanism having excellent load resistance in the bound direction can be realized.

  Further, the second aspect of the present invention is characterized in that a hollow hole is formed in the front end surface of the press-fitting part and extending in the axial direction with respect to the press-fitting part according to the first aspect. And

  In the fluid-filled vibration isolator having the structure according to this aspect, it is required when the press-fitting portion of the main rubber fixing member is pressed into the press-fitting recess of the stopper member by providing a hollow hole in the press-fitting portion. Pressure input can be reduced.

  According to a third aspect of the present invention, in the fluid-filled vibration isolator according to the first or second aspect, at least a part of the abutting portion is overlapped and brought into contact with the stepped portion. It is characterized by that.

  In the fluid-filled vibration isolator having the structure according to this aspect, the contact portion protruding in the direction perpendicular to the axis can be advantageously reinforced and supported by the stepped portion, and the load resistance in the axial direction can be Can be further improved.

  According to a fourth aspect of the present invention, there is provided the fluid filled type vibration damping device according to any one of the first to third aspects, wherein the first fluid chamber is provided in a part of an intermediate portion in the axial direction of the inner shaft body. A tapered portion that gradually decreases in diameter toward the side is formed, and the main rubber elastic body is fixed to the tapered portion of the inner shaft body and the portion closer to the first fluid chamber than the tapered portion. It is characterized by that.

  In the fluid-filled vibration isolator having the structure according to this embodiment, the portion of the inner shaft body to which the main rubber elastic body is fixed is made relatively small in diameter so that the main body rubber elastic body is perpendicular to the axis. The degree of dimensional freedom in the direction can be advantageously ensured, and the spring characteristic of the main rubber elastic body according to the vibration proof characteristic can be advantageously achieved.

  Further, a fifth aspect of the present invention is the fluid-filled vibration isolator according to any one of the first to fourth aspects, wherein an intermediate sleeve is adhered to the outer peripheral surface of the main rubber elastic body, Windows are formed on both sides of the intermediate sleeve in the direction perpendicular to the axis across the first mounting member, and are formed so as to be opposed to each other in the direction perpendicular to the axis and open to the outer peripheral surface of the main rubber elastic body. Each of the pocket portions is opened to the outer peripheral surface through the window portion of the intermediate sleeve, while the second mounting member is fitted and fixed to the intermediate sleeve, and the window portion of the intermediate sleeve is fixed to the second sleeve. By covering the fluid tightly with the mounting member, a pair of second fluid chambers are formed facing each other with the first mounting member sandwiched in the direction perpendicular to the axis, and the pair of second fluid chambers communicate with each other. To form the second orifice passage That was characterized.

  In the fluid-filled vibration isolator having the structure according to this aspect, excellent vibration isolating performance can be exhibited even with respect to vibration input in a direction perpendicular to the axis.

  As is clear from the above description, the fluid-filled vibration isolator having the structure according to the present invention has an excellent load resistance in both the bound direction and the rebound direction while avoiding the enlargement of the entire device. Therefore, it is possible to realize a fluid-filled vibration isolator having characteristics.

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

  First, FIG. 1 and FIG. 2 show an automobile engine mount 10 as a first embodiment of the present invention. The engine mount 10 has a structure in which a first mounting bracket 12 as a first mounting member and a second mounting bracket 14 as a second mounting member are elastically connected by a main rubber elastic body 16. The first mounting bracket 12 is attached to a power unit of an automobile (not shown), while the second mounting bracket 14 is attached to an automobile body (not shown) via an attachment bracket 18 as a cylindrical bracket. As a result, the power unit can be supported in a vibration-proof manner with respect to the body. In the following description, the vertical direction means the vertical direction in FIG.

  More specifically, the first mounting fitting 12 has a substantially cylindrical shape as a whole, and the fixing fitting 20 as the inner shaft body is press-fitted and fitted into the stopper forming fitting 22 as the stopper member. It is constituted by. Further, the stopper forming bracket 22 is formed with a mounting bolt 24 protruding to one side in the axial direction (upward in FIG. 1), and the mounting bolt 24 is screwed to a power unit side member (not shown). Thus, the first mounting bracket 12 is fixed to the power unit.

  In addition, a metal sleeve 26 as an intermediate sleeve having a thin, large-diameter, substantially cylindrical shape is arranged on substantially the same central axis as the first mounting bracket 12 so as to be spaced radially outward of the first mounting bracket 12. It is installed. The metal sleeve 26 has a large diameter through a stepped portion that extends outward in the radial direction with respect to one axial end (axial upper end) of the small-diameter cylindrical portion 28 that extends linearly in the axial direction. The cylindrical portion 30 has a substantially stepped cylindrical shape integrally formed. In addition, a pair of window portions 32 are disposed in the axially intermediate portion of the metal sleeve 26 so as to be opposed to each other with the first mounting member 12 sandwiched in one radial direction in the arrangement state with respect to the first mounting member 12 described later. Is formed. In addition, each window part 32 in this embodiment is formed with an opening with a length of a little less than a half circumference in the circumferential direction. Further, the window portion 32 is formed including a portion in which a stepped portion is formed in the axial direction, and is formed to be biased upward in the axial direction in the main rubber elastic body 16.

  The first mounting bracket 12 and the metal sleeve 26 having such a structure are inserted into the first mounting bracket 12 from an opening on one side of the metal sleeve 26 (upper opening in FIG. 1). Thus, the first mounting member 12 is spaced from the metal sleeve 26 in the direction perpendicular to the axis with the same central axis. In the present embodiment, the first mounting member 12 has the end on one side in the axial direction protruding from the opening on the one side in the axial direction of the metal sleeve 26 and the other in the axial direction. The end of this side is positioned at an axially intermediate portion that does not reach the end of the other side of the metal sleeve 26 in the axial direction.

  A main rubber elastic body 16 is disposed between the first mounting bracket 12 and the metal sleeve 26 facing each other in the direction perpendicular to the axis. The metal fitting 20) and the metal sleeve 26 are elastically connected. The main rubber elastic body 16 has a thick, generally cylindrical shape as a whole, and its inner peripheral surface is vulcanized and bonded to the outer peripheral surface of the first mounting member 12, and its outer peripheral surface is a metal. Vulcanized and bonded to the inner peripheral surface of the sleeve 26. That is, in this embodiment, the main rubber elastic body 16 is an integrally vulcanized molded product 34 including the first mounting bracket 12 (fixing bracket 20) and the metal sleeve 26. The main rubber elastic body 16 is gradually protruded toward both sides in the axial direction as it is separated from the first mounting member 12 outward in the direction perpendicular to the axis. Is gradually growing.

  Further, the main rubber elastic body 16 is formed with a circular recess 36 having an inverted mortar shape that opens downward in the axial direction at the central portion of the lower end surface in the axial direction, and is formed in the axially intermediate portion to form a shaft. A pair of pocket portions 38 that are open in a perpendicular direction are formed. Each of the pair of pocket portions 38 has an expanded shape in which the axial width dimension gradually increases outward in the direction perpendicular to the axis, and is formed with a length of slightly less than a half circumference in the circumferential direction. Further, the inner wall surfaces on both sides in the axial direction of the pocket portion 38 are gradually inclined toward the outer side in the axial direction (upward and downward in the axial direction) as they are separated from the first mounting member 12 in the direction perpendicular to the axial direction. As a result, the wall portions on both axial sides of the pocket portion 38 are inclined and extend with a substantially constant thickness. Further, the wall portions on both sides in the axial direction of the pocket portion 38 are thinner in the wall portion on the upper side in the axial direction than the wall portion on the lower side in the axial direction. Further, the pair of pocket portions 38 are formed on both sides of the first mounting member 12 in one direction perpendicular to the axis and are directed outward in the direction perpendicular to the axis through the window portion 32 formed in the metal sleeve 26. Open.

  On the other hand, the second mounting bracket 14 has a thin cylindrical shape with a large diameter as a whole. Further, a support step 40 is formed in a part of the second mounting bracket 14 in the axial direction, and one side in the axial direction (upward in FIG. 1) sandwiching the support step 40 has a thin large diameter. A peripheral wall portion having a substantially cylindrical shape and a cylindrical shape having a smaller diameter than the holding cylinder portion 42 on the other side in the axial direction (downward in FIG. 1) with the support step 40 interposed therebetween. 44. Furthermore, a diaphragm 46 as a flexible film is disposed in the opening on the peripheral wall 44 side of the second mounting member 14. The diaphragm 46 is formed of a thin elastomer material having a flexure, has a substantially circular dome shape, and can easily be elastically deformed. Further, the outer peripheral edge portion of the diaphragm 46 is vulcanized and bonded to the peripheral wall portion 44 of the second mounting bracket 14 over the entire circumference, so that the diaphragm 46 is opened on the peripheral wall portion 44 side of the second mounting bracket 14. As a result, the opening on the peripheral wall 44 side in the axial direction of the second mounting member 14 is closed fluid-tightly by the diaphragm 46. It should be noted that the inner peripheral surface of the second mounting bracket 14 is covered over substantially the entire surface by a seal rubber layer 48 formed integrally with the diaphragm 46.

  In the second mounting bracket 14 having such a structure, an integrally vulcanized molded product 34 is inserted and disposed on the same central axis from one end in the axial direction, and an opening edge on one side in the axial direction. Is positioned with respect to the opening edge of the metal sleeve 26 on the large-diameter cylindrical portion 30 side, and the second mounting bracket 14 is reduced in diameter by eight-way drawing or the like, whereby an integrally vulcanized molded product 34 is obtained. The second mounting bracket 14 is attached to the (metal sleeve 26) in an externally fitted state. A seal rubber layer 48 is interposed in a compressed state between the fitting surfaces of the second mounting bracket 14 and the metal sleeve 26, and the second mounting bracket 14 and the metal sleeve 26 are fitted in a fluid-tight manner. ing.

  Then, the second mounting bracket 14 is fitted and fixed to the metal sleeve 26 in this manner, so that the first mounting bracket 12 enters from the opening on one side in the axial direction of the second mounting bracket 14. The first mounting bracket 12 and the second mounting bracket 14 are disposed on the same central axis so as to be separated from each other by a predetermined distance in the direction perpendicular to the axis. 16 is elastically connected.

  Further, when the second mounting bracket 14 is externally fixed to the metal sleeve 26 in this way, the opening on the holding cylinder portion 42 side of the second mounting bracket 14 is fluid-tightened by the main rubber elastic body 16. A first fluid chamber 50 in which an incompressible fluid is sealed is formed between the axially opposing surfaces of the main rubber elastic body 16 and the diaphragm 46. As the incompressible fluid sealed in the first fluid chamber 50, for example, water, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof is suitably employed. In particular, as the sealed fluid, it is desirable to employ a low-viscosity fluid having a viscosity of 0.1 Pa · s or less in order to advantageously obtain an anti-vibration effect based on the resonance action of the fluid through the orifice passage described later.

  The first fluid chamber 50 is provided with a partition member 52 having a generally thick disc shape as a whole so as to spread in the direction perpendicular to the axis within the first fluid chamber 50. The partition member 52 is formed by superimposing a thin, substantially disk-shaped lid member 56 on an axially upper surface of a partition member main body 54 that has a thick, substantially disk shape. Further, the partition member 52 has its outer peripheral edge sandwiched and held between the opposed surfaces of the lower end surface in the axial direction of the main rubber elastic body 16 and the upper surface of the support step 40 of the second mounting bracket 14. Is accommodated and disposed so as to spread in the direction perpendicular to the axis between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 46.

  In this way, the partition member 52 is disposed so as to extend in the direction perpendicular to the axis between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 46, so that the first fluid chamber 50 sandwiches the partition member 52 and moves up and down. It is supposed to be divided into two. Thereby, a part of the wall portion is constituted by the main rubber elastic body 16 on the upper side of the partition member 52 in the axial direction, and pressure fluctuation is caused based on elastic deformation of the main rubber elastic body 16 at the time of vibration input. On the other hand, a chamber 58 is formed. On the lower side in the axial direction of the partition member 52, a part of the wall portion is constituted by the diaphragm 46, and the volume change due to the deformation of the diaphragm 46 is easily allowed. Is formed. In the present embodiment, the lower surface recess 62 that opens downward in the axial direction is formed in the central portion of the lower surface of the partition member main body 54, so that the partition member 52 can effectively avoid interference with the deformation of the diaphragm 46. is doing.

  Further, the partition member 52 is formed with a groove 64 that opens to the outer peripheral surface and extends in the circumferential direction with a length of a little less than one round. The opening of the groove 64 is fluid-tight by the second mounting bracket 14. A tunnel-like flow path is formed by being closed. Further, both end portions of the tunnel-shaped flow path are connected to the pressure receiving chamber 58 and the equilibrium chamber 60, respectively, and the flow path extends in the circumferential direction of the outer periphery of the partition member 52 to balance the pressure receiving chamber 58. A first orifice passage 66 is formed which communicates the chamber 60 with each other. As a result, the pressure receiving chamber 58 and the equilibrium chamber 60 are always in communication with each other through the first orifice passage 66, and the flow of the sealed fluid occurs between the pressure receiving chamber 58 and the equilibrium chamber 60 through the first orifice passage 66. It is supposed to be. In particular, in this embodiment, by adjusting the passage length and the passage cross-sectional area of the first orifice passage 66, a high damping effect based on the resonance action of the fluid that flows through the first orifice passage 66, etc. It is designed for vibration input in the low frequency range corresponding to shake.

  On the other hand, when the second mounting bracket 14 is externally fixed to the metal sleeve 26, the pair of window portions 32 formed in the metal sleeve 26 are covered with the second mounting bracket 14 in a fluid-tight manner. Yes. As a result, the openings of the pair of pocket portions 38 are covered with the second mounting bracket 14, and a pair of incompressible fluids are sealed on both sides of the first mounting bracket 12 in one direction perpendicular to the axis. A working fluid chamber 68 as a second fluid chamber is formed. These working fluid chambers 68 are filled with incompressible fluid similar to the incompressible fluid sealed in the first fluid chamber 50.

  A cylindrical orifice member 70 is disposed between the opposing surfaces of the second mounting bracket 14 and the metal sleeve 26. The cylindrical orifice member 70 has a substantially cylindrical shape having a circumferential length of more than half a circumference (in this embodiment, a circumferential length of about 3/4 circumference), and is made of a hard material such as synthetic resin or metal. It is formed. Further, in the present embodiment, the inner diameter dimension of the cylindrical orifice member 70 is substantially the same as or slightly larger than the outer diameter dimension of the small diameter cylindrical portion 28 in the metal sleeve 26, and the outer diameter dimension of the cylindrical orifice member 70. Is substantially the same as the outer diameter of the large-diameter cylindrical portion 30 of the metal sleeve 26. Further, the cylindrical orifice member 70 is assembled by being externally attached to the metal sleeve 26 from the axial end portion on the small diameter cylindrical portion 28 side of the metal sleeve 26, and one axial direction side of the cylindrical orifice member 70. The end portion (on the upper side in the axial direction) is extrapolated with respect to the pocket portion 38, and the end surface on the other side in the axial direction (the lower side in the axial direction) is on the upper surface of the support step 40 of the second mounting bracket 14. The cylindrical orifice member 70 is positioned between the inner peripheral surface of the holding cylindrical portion 42 of the second mounting bracket 14 and the outer peripheral surface of the small-diameter cylindrical portion 28 of the metal sleeve 26. It is clamped and held over the entire circumference, positioned and fixed in the direction perpendicular to the axis, and fixedly assembled to the second mounting bracket 14 and the metal sleeve 26.

  Furthermore, a concave groove 72 extending in the circumferential direction by reciprocating or meandering is formed in the cylindrical orifice member 70 so as to open to the outer peripheral surface. Further, the opening of the concave groove 72 is covered fluid-tightly by the holding cylinder portion 42 of the second mounting bracket 14 that is overlapped with the outer peripheral surface of the cylindrical orifice member 70, thereby forming a tunnel-like flow path. Has been. Then, both ends of the tunnel-shaped flow path are connected to the respective working fluid chambers 68 through through holes (not shown) formed in the bottom wall surfaces at both end portions of the concave groove 72, whereby the pair of working fluid chambers 68 are formed. A second orifice passage 74 that communicates with each other is formed, and the pair of working fluid chambers 68 are always in communication with each other by the second orifice passage 74. In the present embodiment, a high damping effect is obtained against low frequency vibrations such as engine shakes based on the resonance action of the fluid that flows between the pair of working fluid chambers 68 through the second orifice passage 74. As described above, the length and the cross-sectional area of the second orifice passage 74 are adjusted.

  A mounting bracket 18 is fitted and fixed to the second mounting bracket 14. The mounting bracket 18 has a substantially cylindrical shape as a whole, and a stopper contact portion 76 as an inner flange-shaped contact portion that extends inward in the direction perpendicular to the axis is integrally formed at an end portion on one side in the axial direction. In addition, a flange-like attachment portion 78 that extends outward in the direction perpendicular to the axis is formed at the end on the other side in the axial direction. In the present embodiment, the attachment portion 78 has a substantially oval shape, and a pair of bolt holes 80 are formed in one direction perpendicular to the axis that is the major axis direction of the attachment portion 78, and the attachment bracket The second mounting bracket 14 is fixed to the vehicle body side by bolting 18 to a member on the vehicle body side (not shown). As a result, the first mounting bracket 12 is fixed to a power unit (not shown), and the second mounting bracket 14 is fixed to a vehicle body (not shown) via the mounting bracket 18, so that the power unit is attached to the vehicle body. It is elastically connected via the engine mount 10.

  Here, in the engine mount 10 according to the present embodiment, as described above, the first mounting bracket 12 is constituted by the fixing bracket 20 and the stopper forming bracket 22.

  The fixing metal fitting 20 is a substantially cylindrical shaft body that extends in the axial direction as a whole, and is disposed at the central portion of the main rubber elastic body 16 in the direction perpendicular to the axis. Further, the fixing bracket 20 is formed with a step portion 82 at a part in the middle in the axial direction, and a main rubber fixing portion 84 as a fixing portion having a relatively large diameter in the lower part in the axial direction across the step portion 82. On the other hand, the upper part in the axial direction is a press-fitting protrusion 86 as a press-fitting part having a smaller diameter than the main rubber fixing part 84.

  The main rubber adhering portion 84 has a solid substantially cylindrical shape, and a tapered portion 88 is provided at a part of the middle in the axial direction. The taper portion 88 has a tapered shape that gradually decreases in diameter toward the lower side in the axial direction. The upper portion in the axial direction is a large-diameter portion 90 across the taper portion 88, and the lower portion in the axial direction is a small-diameter portion 92. Has been. Further, the main rubber elastic body 84 is bonded to the outer peripheral surface of the main rubber elastic body 16 by vulcanization, and is fixed to the center of the main rubber elastic body 16 in the direction perpendicular to the axis. In the present embodiment, the main rubber elastic body 16 is fixed over substantially the entire outer peripheral surface of the tapered portion 88 and the small diameter portion 92 of the main rubber fixing portion 84, and the large diameter portion 90 is the main rubber elastic body. 16 is projected upward in the axial direction.

  A press-fit protrusion 86 is integrally formed on the upper end surface in the axial direction of the large-diameter portion 90. The press-fitting protrusion 86 has a substantially cylindrical shape having a smaller diameter than the large-diameter portion 90, and protrudes upward in the axial direction from the axial upper end surface of the large-diameter portion 90. Further, a guide inclined surface 94 is formed on the outer peripheral edge portion of the projecting tip portion of the press-fit projection 86 so as to gradually incline in the direction perpendicular to the axis toward the projecting tip side. The outer diameter is gradually reduced in the protruding direction. In the present embodiment, a hollow hole 96 is formed in the press-fitting protrusion 86. The hollow hole 96 is a bottomed circular hole that is opened on the protruding tip surface of the press-fitting protrusion 86 and extends linearly in the axial direction. The depth reaches the upper end of 84. In the present embodiment, the fill hole 96 is formed so as to extend on the substantially central axis of the press-fit protrusion 86, and the press-fit protrusion 86 is formed in a substantially cylindrical shape by forming the fill hole 96. It is said that.

  On the other hand, the stopper forming bracket 22 has a press-fitting cylinder portion 98 and a contact flange portion 100 as a contact portion. The press-fitting cylinder portion 98 has a substantially bottomed cylindrical shape with a reverse direction having a press-fitting hole 102 as a press-fitting recess that opens at the lower end surface in the axial direction, and its inner diameter dimension is slightly smaller than the outer diameter dimension of the press-fit projection 86. The outer diameter is slightly smaller than the outer diameter of the large-diameter portion 90 of the fixing bracket 20. Further, the depth dimension of the press-fitting hole 102 is substantially equal to the projecting height dimension of the press-fitting protrusion 86. A mounting bolt 24 that protrudes upward in the axial direction is provided on the upper bottom portion of the stopper forming bracket 22. In the present embodiment, the opening of the press-fitting hole 102 is configured by a tapered guide surface 104 that is gradually inclined in the direction perpendicular to the axis toward the opening, and the press-fitting hole 102 is open on the opening side in the vicinity of the opening. The diameter is gradually increased toward.

  Furthermore, the contact flange portion 100 is formed integrally with the lower end portion in the axial direction of the stopper forming metal member 22 and has a flange shape that extends outward in the axial direction. In addition, a buffer rubber 106 is vulcanized and bonded to the contact flange portion 100 so as to cover from the center side end portion in the direction perpendicular to the axis on the upper surface to the middle portion in the direction perpendicular to the axis on the lower surface of the contact flange portion 100. . Note that the material, shape, and the like of the buffer rubber 106 can be appropriately selected and adopted according to the required stopper performance and the like. In particular, in the present embodiment, the inner peripheral edge of the contact flange portion 100 is overlapped with the step portion 82 and brought into contact therewith.

  The fixing metal fitting 20 and the stopper forming metal piece 22 are integrated by press-fitting the press-fitting protrusion 86 formed in the fixing metal fitting 20 into the press-fitting hole 102 formed in the stopper forming metal piece 22 from below in the axial direction. Thus, the first mounting member 12 in this embodiment is formed. As a result, the first mounting member 12 includes a flange-shaped contact flange portion 100 that extends in a direction perpendicular to the axis at a portion in the middle in the axial direction. In the present embodiment, the depth dimension of the press-fitting hole 102 provided in the stopper-forming metal fitting 22 and the protrusion height dimension of the press-fit protrusion 86 provided in the fixing metal fitting 20 are substantially equal. A part of the lower end surface of the fixing metal fitting 20 is overlapped with the stepped portion 82 of the fixing metal fitting 20 in the axial projection, and the stopper forming metal fitting 22 is positioned with respect to the fixing metal fitting 20 in the axial direction.

  Then, the contact flange portion 100 of the first mounting bracket 12 is separated from the stopper contact portion 76 provided on the mounting bracket 18 fixed to the second mounting bracket 14 by a predetermined distance in the axial direction. Since the contact flange portion 100 and the stopper contact portion 76 are brought into contact with each other in the axial direction via the buffer rubber 106 provided on the contact flange portion 100, the first mounting bracket is placed. A rebound stopper mechanism according to the present embodiment is configured to limit the relative distance between the 12 and the second mounting member 14 in the axial direction. The separation distance between the contact flange portion 100 and the stopper contact portion 76 is appropriately set according to the stopper performance required for the rebound stopper mechanism, the shape of the buffer rubber 106, and the like.

  In particular, in the present embodiment, the main rubber elastic body 16 is configured such that the axial dimension gradually increases from the first mounting bracket 12 side (inner side in the direction perpendicular to the axis) toward the metal sleeve 26 side (outer in the direction perpendicular to the axis). And the upper end surface in the axial direction of the main rubber elastic body 16 is gradually inclined upward in the axial direction outward in the direction perpendicular to the axial direction, so that the metal sleeve 26 is positioned above the main rubber elastic body 16 in the axial direction. A recessed space is formed in the inner portion of the upper end portion in the direction perpendicular to the axis. In addition, since the stepped portion 82 of the fixing bracket 20 is positioned below the upper end of the metal sleeve 26 in the axial direction, the stepped portion 82 is brought into contact with the upper end surface in the axial direction of the stepped portion 82 and is positioned in the axial direction. The contact flange portion 100 is accommodated and disposed in the recessed space formed in the axially upper direction of the main rubber elastic body 16.

  In the engine mount 10 for automobiles having the above-described structure, the vertical mounting direction (in FIG. 1, the vertical direction) between the first mounting bracket 12 and the second mounting bracket 14 when mounted on the vehicle. ), When a low frequency large amplitude vibration is input, a relative pressure difference is generated between the pressure receiving chamber 58 and the equilibrium chamber 60. The pressure difference causes a positive fluid flow between the pressure receiving chamber 58 and the equilibrium chamber 60 through the first orifice passage 66, and a high damping effect is exhibited based on the resonance action of the flowing fluid. It has come to be.

  Here, a substantially vertical vibration load is input between the first mounting bracket 12 and the second mounting bracket 14, and the first mounting bracket 12 and the second mounting bracket 14 are separated from each other in the axial direction. When the relative displacement is greater than a predetermined amount (distance between the opposing surfaces of the upper surface of the buffer rubber 106 and the lower surface of the stopper contact portion 76), the stopper is formed integrally with the stopper forming metal member 22 constituting the first mounting member 12. The abutting flange portion 100 is displaced in the axial direction relative to the mounting bracket 18 fixed to the second mounting bracket 14, and the abutting flange portion 100 is attached to the mounting bracket 18 via the buffer rubber 106. The stopper comes into contact with the stopper contact portion 76 in the axial direction. Thereby, the relative displacement in the axial direction of the first mounting bracket 12 and the second mounting bracket 14 is limited in a buffering manner, and excessive shear deformation of the main rubber elastic body 16 can be prevented.

  On the other hand, when low-frequency vibration in a substantially horizontal direction (left and right direction in FIG. 1) is input between the first mounting bracket 12 and the second mounting bracket 14 under the vehicle mounting state, a pair of working fluids A relative pressure difference is generated between the chambers 68 and 68, and a fluid flow through the second orifice passage 74 is generated based on the pressure difference. The effect is exhibited effectively. In the present embodiment, the buffer rubber 106 is also fixed to the outer surface in the direction perpendicular to the axis of the contact flange portion 100, so that the first in the direction perpendicular to the axis is formed by the contact flange portion 100 and the metal sleeve 26. It is also possible to implement a horizontal stopper mechanism that limits the relative displacement of the mounting bracket 12 and the second mounting bracket 14.

  In the automobile engine mount 10 having the structure according to this embodiment, the first mounting bracket 12 is formed by the contact flange portion 100 of the first mounting bracket 12 and the stopper contact portion 76 of the mounting bracket 18. And the rebound stopper mechanism which restrict | limits the relative displacement amount in the axial direction of the 2nd attachment bracket 14 is comprised. Therefore, excellent load resistance can be exhibited with respect to the input load in the mount axis direction, which is the main vibration input direction.

  In such an engine mount 10, the diameter of the press-fitting protrusion 86 is increased by overlapping the lower end surface in the axial direction of the stopper forming bracket 22 in the axial direction with the stepped portion 82 where the fixing bracket 20 is provided. The contact area between the fixing metal fitting 20 and the stopper forming metal fitting 22 can be advantageously obtained without this. Therefore, it is possible to realize a rebound stopper mechanism having excellent load resistance against vibration loads in the bound direction.

  Further, since the overlapping area of the fixing metal fitting 20 and the stopper forming metal fitting 22 can be advantageously ensured by the step portion 82, the size of the entire vibration isolator by increasing the diameter of the press-fit protrusion 86. The size of the contact portion extending in the direction perpendicular to the axis (projected area in the axial direction of the contact portion) can be advantageously ensured while avoiding an increase in size. Therefore, the contact area between the contact part and the contacted part can be advantageously obtained, and the stress at the time of contact can be dispersed, so the rebound stopper has excellent load resistance in the rebound direction. The mechanism can be realized.

  Further, by providing the press-fitting protrusion 86 with the hollow hole 96, the pressure input required when the press-fitting protrusion 86 in the fixing metal fitting 20 is press-fitted into the press-fitting hole 102 provided in the stopper forming metal fitting 22. Can be reduced.

  By providing such a hollow hole 96, the contact area between the protruding front end surface of the press-fitting protrusion 86 and the bottom surface of the press-fitting hole 102 is reduced, but the fixing bracket 20 and the stopper forming bracket 22 in the present embodiment. Then, not only the protruding front end surface of the press-fitting protrusion 86 and the bottom surface of the press-fitting hole 102 are brought into contact with each other, but also the stepped portion 82 in the fixing fitting 20 and the lower end surface in the axial direction of the stopper forming fitting 22 are brought into contact with each other. The contact area capable of realizing excellent load resistance can also be ensured by forming the hollow hole 96 in the press-fitting protrusion 86.

  Further, the inner edge portion in the direction perpendicular to the axis of the contact flange portion 100 is superposed on the step portion 82 of the fixing bracket 20, so that the contact flange portion 100 that protrudes outward in the direction perpendicular to the axis is stepped 82. Thus, it can be reinforced and supported advantageously from below in the axial direction, and the load resistance in the rebound direction can be obtained more advantageously.

  Further, the main rubber elastic body 16 is fixed to the outer peripheral surfaces of the tapered portion 88 and the small diameter portion 92 of the main rubber fixing portion 84 of the fixing metal 20, and the large diameter portion 90 of the fixing metal 20 is elastic of the main rubber. It projects from the body 16 upward in the axial direction. As a result, a portion of the main rubber fixing portion 84 to which the main rubber elastic body 16 is fixed has a relatively small diameter, and the main rubber elastic body does not increase in size in the direction perpendicular to the axis of the engine mount 10. 16 dimensional freedom in the direction perpendicular to the axis can be advantageously obtained. Therefore, it is possible to advantageously secure a degree of freedom in tuning the spring characteristics according to the required vibration isolation characteristics.

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

  For example, in the embodiment described above, a pair of working fluid chambers 68 formed by sandwiching the first mounting member 12 in the direction perpendicular to the axis in order to obtain effective vibration isolation performance against vibration input in the direction perpendicular to the axis. The engine mount 10 having the second orifice passage 74 that communicates the pair of working fluid chambers 68 with each other is illustrated. However, the present invention is directed to the engine mount 10 having such a working fluid chamber 68. It can be applied to various fluid-filled vibration damping devices. In addition, the shape, dimensions, etc. of the main rubber elastic body are determined according to the required vibration isolating characteristics, etc., and are not limited by the specific shapes, etc. described in the above embodiment. .

  Moreover, in the said embodiment, although the engine mount 10 provided only with the rebound stopper mechanism which restrict | limits the relative displacement of the 1st mounting bracket 12 and the 2nd mounting bracket 14 in a rebound direction was shown, the 1st in a bound direction is shown. A bound stopper mechanism that limits the relative displacement between the one mounting bracket 12 and the second mounting bracket 14 may be provided. In addition, as such a bound stopper mechanism, various well-known bound stopper mechanisms can be adopted. Preferably, for example, the bound stopper mechanism is press-fitted from above in the axial direction to the stopper forming metal member 22 and attached in an extrapolated state. A substantially annular plate-shaped bound stopper member is disposed above the stopper contact portion 76 in the mounting bracket 18 in the axial direction so as to be opposed to the stopper contact portion 76 in the axial direction, and the lower surface of the bound stopper member. And the upper surface of the stopper abutting portion 76 are brought into contact with each other via a buffer rubber, thereby realizing a bound stopper mechanism for limiting the relative displacement amount in the bound direction between the first mounting bracket 12 and the second mounting bracket 14. I can do it.

  Further, in the above-described embodiment, in order to facilitate the press-fitting of the press-fitting protrusion 86 into the press-fitting hole 102, the press-fitting protrusion 86 is provided with the hollow hole 96, but such a hollow hole 96 is not necessarily required. . Further, the shape of the hollow hole 96 is not necessarily limited to that of the above embodiment.

  Further, in the above-described embodiment, the portion where the main rubber elastic body 16 is fixed in the fixing metal fitting 20 is the tapered portion 88 and the small diameter portion 92, and has a smaller diameter than the large diameter portion 90. The tapered portion 88 is not always necessary. For example, the main rubber fixing portion 84 may be formed with a substantially constant dimension over the entire length in the axial direction.

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

It is a longitudinal cross-sectional view which shows the engine mount as one Embodiment of this invention, Comprising: It is a figure corresponded in the II cross section in FIG. FIG. 2 is a transverse cross-sectional view showing the engine mount shown in FIG. 1, corresponding to a II-II cross section in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine mount 12 1st mounting bracket 14 2nd mounting bracket 16 Main body rubber elastic body 18 Mounting bracket 20 Fastening bracket 22 Stopper formation bracket 46 Diaphragm 50 First fluid chamber 52 Partition member 58 Pressure receiving chamber 60 Equilibrium chamber 66 First Orifice passage 76 Stopper contact portion 82 Stepped portion 84 Body rubber adhering portion 86 Press-fit protrusion 100 Contact flange portion 102 Press-fit hole 106 Buffer rubber

Claims (5)

The first mounting member is arranged to enter the axial direction on the central axis from one opening in the axial direction of the second mounting member having a cylindrical shape, and is arranged at a predetermined distance in the direction perpendicular to the axis. The second mounting member and the second mounting member are connected in the direction perpendicular to the axis with the main rubber elastic body, while the other axial opening of the second mounting member is fluid-tightly closed with a flexible membrane, Forming a first fluid chamber in which an incompressible fluid is enclosed between the opposing surfaces of the main rubber elastic body and the flexible membrane on the inner peripheral side of the second mounting member; The first fluid chamber is partitioned by a partition member supported by a member, and a pressure receiving chamber in which a part of the wall part is configured by the main rubber elastic body, and a part of the wall part is configured by the flexible film. The equilibrated chambers are formed on both sides of the partition member, and a first orifice passage is provided to communicate the pressure receiving chamber and the equilibrated chamber with each other. In the fluid filled type vibration damping apparatus,
The first attachment member includes an inner shaft body fixed to the main rubber elastic body and a stopper member attached to the inner shaft body, and the inner shaft body includes a part in the middle in the axial direction. A step portion is formed on one side in the axial direction with the step portion interposed therebetween, and the other side in the axial direction is a fixing portion having a larger diameter than the press-in portion, The press-fitting portion protrudes from the main rubber elastic body toward one side in the axial direction, and the main rubber elastic body is vulcanized and bonded to the outer peripheral surface of the fixing portion. A press-fit recess is formed in the other end surface in the axial direction. The press-fit portion is press-fitted in the press-fit recess in the axial direction and at least one of the lower end surfaces of the stopper member. The part is superimposed on the stepped part As a result, the inner shaft body and the stopper member are positioned and fixed to each other to constitute the first mounting member. On the opening edge of the press-fit recess, a contact portion extending in a direction perpendicular to the axis is formed. The corresponding contact portion is axially opposed to the contacted portion formed on the cylindrical bracket attached to the second mounting member in an extrapolated state. A buffer rubber is fixed to at least one of the contacted portions, and the first mounting member is pulled out in the axial direction with respect to the second mounting member based on the buffered contact between the corresponding contact portion and the contacted portion. A fluid-filled vibration isolator comprising a rebound stopper mechanism for limiting a relative displacement amount in an outgoing direction.   The fluid-filled vibration isolator according to claim 1, wherein a hollow hole is formed in the distal end surface of the press-fitting portion and extending in the axial direction with respect to the press-fitting portion.   The fluid filled type vibration damping device according to claim 1, wherein at least a part of the abutting portion is overlapped with and abutted on the stepped portion.   A taper portion that gradually decreases in diameter toward the first fluid chamber side is formed in a part of the middle in the axial direction of the inner shaft body, and the taper portion and the taper portion in the inner shaft body are more The fluid-filled type vibration damping device according to any one of claims 1 to 3, wherein the main rubber elastic body is fixed to a portion on one fluid chamber side. An intermediate sleeve is bonded to the outer peripheral surface of the main rubber elastic body, and window portions are formed on both sides of the first sleeve in the direction perpendicular to the axis with the first mounting member interposed therebetween. A pocket portion that is formed to open to the outer peripheral surface of the main rubber elastic body is opened to the outer peripheral surface through the window portion of the intermediate sleeve, and the second mounting member is fitted to the intermediate sleeve. A pair of second fluids that are positioned opposite each other with the first mounting member sandwiched in the direction perpendicular to the axis by covering and fixing the window portion of the intermediate sleeve fluid-tightly with the second mounting member. The fluid-filled vibration isolator according to any one of claims 1 to 4, wherein a chamber is formed and a second orifice passage is formed so that the pair of second fluid chambers communicate with each other.

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