JP4528661B2 - Vibration isolator - Google Patents

Description

  The present invention is used as an engine mount or the like in general industrial machines and automobiles, and absorbs vibration from a vibration generating part of an engine or the like to prevent vibration transmission to a vibration receiving part of a vehicle body or the like. It is about.

  For example, an anti-vibration device as an engine mount is disposed between an engine that is a vibration generation unit of a vehicle and a vehicle body that is a vibration receiving unit, and the anti-vibration device absorbs vibration generated by the engine, Suppresses vibration transmission to the vehicle body. As such a vibration isolator, an elastic body, a pressure receiving liquid chamber and a sub liquid chamber are provided inside the apparatus, and a liquid sealed type in which these liquid chambers communicate with each other through a restriction passage is known. According to such a vibration isolator, when vibration is generated by operating the mounted engine, the vibration absorbing action of the elastic body and the viscous resistance of the liquid flowing through the orifice communicating between the pair of liquid chambers The vibration is absorbed by, for example, and vibration transmission to the vehicle body side is suppressed.

  As a conventional liquid-filled vibration isolator, for example, there is one as shown in Patent Document 1. The vibration isolator described in Patent Document 1 includes a cylindrical metal fitting, a mounting metal fitting disposed on the inner peripheral side of the cylindrical metal fitting, and an elastic body that elastically connects the mounting metal fitting to the cylindrical metal fitting. is doing. The vibration isolator is provided with an upper liquid chamber having an elastic body as a part of an inner wall, a lower liquid chamber having a diaphragm as a part of a partition wall, and a first orifice for communicating the liquid chambers with each other. The four peripheral liquid chambers C1, C2, D1, and D2 that are arranged along the circumferential direction between the metal fitting and the elastic body, each of which has the elastic body as a part of the inner wall, and the four peripheral liquid chambers. Among them, there are provided a second orifice that communicates two (one set) adjacent peripheral fluid chambers C1 and D1, and a third orifice that communicates another set of peripheral fluid chambers C2 and D2.

In the vibration isolator configured as described above, in addition to the upper liquid chamber and the lower liquid chamber communicated with each other by the first orifice, four peripheral liquid chambers C1, C2, and D1 are provided between the cylindrical metal fitting and the elastic body. , D2 and the peripheral fluid chambers C1 and D1 communicate with each other through the second orifice, and the peripheral fluid chambers C2 and D2 communicate with each other through the third orifice. When applied, when vibration in the vertical direction is input, this vibration can be absorbed and absorbed by the internal friction of the elastic body or the viscous resistance of the liquid. In addition, it can be effectively attenuated and absorbed by the viscous resistance of the liquid flowing through the second and third orifices.
JP 2004-68938 A

  However, in the vibration isolator of Patent Document 1, if the internal volumes of the plurality of peripheral fluid chambers are made sufficiently large, the partition wall portion of the elastic body that partitions these peripheral fluid chambers is thin. It becomes difficult to make the length of the orifice path formed in the partition wall sufficiently long. For this reason, in the vibration isolator of Patent Document 1, unless the size of the apparatus is increased, the path length of the orifice communicating with the peripheral fluid chamber can be tuned so as to be adapted to vibration of a low frequency (for example, 10 Hz or less). When the vibration input along the left-right direction or the front-rear direction of the vehicle has a low frequency, there arises a problem that such vibration cannot be effectively attenuated and absorbed.

  In view of the above facts, the object of the present invention is to effectively attenuate and absorb vibrations input along the axial direction of the apparatus while suppressing an increase in the size of the apparatus. An object of the present invention is to provide a vibration isolator capable of effectively attenuating and absorbing vibration even when the frequency of vibration input along the first and second sub-amplitude directions is low.

In order to achieve the above object, a vibration isolator according to claim 1 of the present invention is connected to one of a vibration generating portion and a vibration receiving portion, and includes a first mounting member formed in a substantially cylindrical shape, a vibration generating portion, A second mounting member connected to the other of the vibration receiving portions and disposed on the inner peripheral side of the first mounting member, and disposed between the first mounting member and the second mounting member. And an elastic body made of rubber that elastically connects the second mounting member and an inner peripheral side of the first mounting member that is provided outside in the axial direction of the second mounting member and at least one of the inner walls. The first pressure receiving liquid chamber is formed of the elastic body and filled with the liquid, and the liquid is filled, and a part of the partition is formed by the diaphragm so that the internal volume can be expanded and contracted according to the change in the liquid pressure. A first liquid chamber, a first pressure receiving liquid chamber, and a second liquid chamber communicating with each other. A limit passage and a first sub-amplitude direction orthogonal to the axial direction are provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member therebetween, and at least a part of an inner wall is A pair of second pressure receiving liquid chambers formed of an elastic body and filled with a liquid; a pair of second restriction passages that respectively connect the pair of second pressure receiving liquid chambers to the sub liquid chamber; A second sub-amplitude direction orthogonal to the first sub-amplitude direction is provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member therebetween, and at least a part of an inner wall is the elastic body And a pair of third pressure receiving liquid chambers filled with liquid, and a pair of third restriction passages that respectively connect the pair of third pressure receiving liquid chambers to the sub liquid chamber. .

  The operation of the vibration isolator according to claim 1 of the present invention will be described below.

  In the vibration isolator according to claim 1, when vibration is input to one of the first and second mounting members from the vibration generating unit side, the vibration is disposed between the first mounting member and the second mounting member due to the input vibration. The elastic body is elastically deformed, the vibration is absorbed by the damping action based on the internal friction of the elastic body, and the vibration transmitted to the vibration receiving portion side is reduced. At this time, even if the input vibration is a vibration in the main amplitude direction substantially coincident with the axial direction of the apparatus, even if the vibration is in a direction (first and second sub-amplitude directions) substantially orthogonal to the main amplitude direction Part of it is absorbed by the body's damping action.

Further, in the vibration isolator according to claim 1, the first pressure receiving liquid chamber disposed on the inner peripheral side of the first mounting member and outside the second mounting member in the axial direction passes through the first restricting passage, and the sub liquid chamber. When the vibration along the main amplitude direction is input to the first mounting member or the second mounting member, the elastic body is elastically deformed along the main amplitude direction, and the internal volume of the first pressure receiving liquid chamber is reduced. Since the expansion and contraction occur, the liquid flows through the first pressure receiving liquid chamber and the sub liquid chamber through the first restriction passage. At this time, if the path length and the cross-sectional area in the first restriction passage, that is, the flow resistance of the liquid is set (tuned) so as to match the vibration frequency input along the main amplitude direction, the first restriction passage will pass through the first restriction passage. A resonance phenomenon occurs in the liquid that flows between the first pressure receiving liquid chamber and the sub liquid chamber between the first pressure receiving liquid chamber and the sub liquid chamber in synchronization with the input vibration. Input vibration along the main amplitude direction can be effectively absorbed by the accompanying pressure change and viscous resistance.

  In the vibration isolator according to claim 1, the pair of second pressure receiving members provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member along the first sub-amplitude direction orthogonal to the axial direction. When the liquid chamber communicates with the sub liquid chamber through the pair of second restricting passages, when the vibration along the first sub amplitude direction is input to the first mounting member or the second mounting member, the elastic body is While elastically deforming along the amplitude direction and expanding and contracting the internal volumes of the pair of second pressure receiving liquid chambers, the liquid between the pair of second pressure receiving liquid chambers and the sub liquid chamber passes through the pair of second restriction passages. Circulate mutually. At this time, if the path length and the cross-sectional area of the pair of second restriction passages, that is, the flow resistance of the liquid is set (tuned) so as to match the vibration frequency input along the first sub-amplitude direction, Since a resonance phenomenon (liquid column resonance) occurs in the liquid flowing between the second pressure receiving liquid chamber and the sub liquid chamber through the restriction passage in synchronization with the input vibration, the pressure change of the liquid accompanying the liquid column resonance and The input vibration along the first sub-amplitude direction can be effectively absorbed by the viscous resistance.

  In the vibration isolator according to the first aspect, the second mounting member is provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member along the second sub-amplitude direction orthogonal to the axial direction and the first sub-amplitude direction. When the vibration along the second sub-amplitude direction is input to the first mounting member or the second mounting member by connecting the pair of third pressure receiving liquid chambers to the sub liquid chamber through the pair of third restriction passages, The elastic body elastically deforms along the second sub-amplitude direction and expands / contracts the internal volumes of the pair of third pressure receiving liquid chambers. Therefore, the pair of third pressure receiving liquid chambers and the sub liquid chambers are paired with each other. The liquid flows through the third restriction passage. At this time, if the path length and the cross-sectional area of the pair of third restriction passages, that is, the flow resistance of the liquid is set (tuned) so as to match the vibration frequency input along the second sub-amplitude direction, Since a resonance phenomenon (liquid column resonance) occurs in the liquid flowing between the third pressure receiving liquid chamber and the sub liquid chamber through the restriction passage in synchronization with the input vibration, the pressure change of the liquid accompanying the liquid column resonance and The input vibration along the second sub-amplitude direction can be effectively absorbed by the viscous resistance.

  In the vibration isolator according to claim 1, the pair of second pressure receiving liquid chambers and the pair of third pressure receiving liquid chambers are provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member therebetween, At least a part of the inner walls of the pair of second pressure receiving liquid chambers and the pair of third pressure receiving liquid chambers is formed by an elastic body, but the arrangement of the sub liquid chambers is similar to that of the first and second pressure receiving liquid chambers. Since it can be arranged at a position separated from the elastic body without being limited, the intervals between the second pressure receiving liquid chamber and the third pressure receiving liquid chamber and the sub liquid chamber are sufficiently widened, and the second pressure receiving liquid chamber and the third pressure receiving liquid chamber The length of the second restriction passage and the length of the third restriction passage that communicate with the pressure receiving liquid chamber and the sub liquid chamber can be made sufficiently long. As a result, according to the vibration isolator according to claim 1, the path length of the second restricted passage and the length of the third restricted passage are adapted to the vibration in the low frequency range while suppressing the enlargement of the device size. Can be tuned easily.

  A vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein the plurality of second pressure receiving liquid chambers and the sub liquid chambers are provided on the inner peripheral side of the first mounting member. In addition to partitioning, partition members each having the second restriction passage and the third restriction passage are provided.

  The vibration isolator according to claim 3 of the present invention is the vibration isolator according to claim 1 or 2, wherein the elastic body substantially coincides with the axial direction to the first mounting member or the second mounting member. When elastically deformed by the input of vibration along the main amplitude direction, the internal volume of the first pressure receiving liquid chamber is mainly expanded or contracted by elastic deformation along the main amplitude direction.

The vibration isolator according to claim 4 of the present invention is the vibration isolator according to any one of claims 1 to 3, wherein the elastic body is attached to the first attachment member or the second attachment member. When elastically deformed by the input of vibration along the first sub-amplitude direction, the internal volume of the second pressure receiving liquid chamber is mainly expanded or contracted by elastic deformation along the first sub-amplitude direction.
The vibration isolator according to claim 5 of the present invention is the vibration isolator according to any one of claims 1 to 4, wherein the elastic body is attached to the first attachment member or the second attachment member. When elastically deforming by the input of vibration along the second sub-amplitude direction, the internal volume of the second pressure receiving liquid chamber is mainly expanded or contracted by elastic deformation along the second sub-amplitude direction.

  As described above, according to the vibration isolator of the present invention, it is possible to effectively attenuate and absorb vibration input along the axial direction of the apparatus while suppressing increase in the size of the apparatus, and substantially orthogonal to the axial direction. An object of the present invention is to provide a vibration isolator capable of effectively attenuating and absorbing this vibration even when the frequency of vibration input along the first and second sub-amplitude directions is low.

  Hereinafter, a vibration isolator according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a vibration isolator according to an embodiment of the present invention. The vibration isolator 10 is used, for example, as an engine mount in an automobile, and supports an engine serving as a vibration generating unit on a vehicle body serving as a vibration receiving unit. In the figure, symbol S indicates the axial center of the apparatus, and the following description will be given with the direction along the axial center S as the axial direction of the apparatus.

  As shown in FIG. 1, the vibration isolator 10 includes a device main body 12 formed in a substantially cylindrical shape, and a bracket 14 for connecting and fixing the device main body 12 to the vehicle body side. A cylindrical holder portion 16 is formed on the bracket 14 on the upper side, and a pair of leg portions 18 extending in a radial direction from the lower end portion of the holder portion 16 are integrally formed. At the tip end portions of the pair of leg portions 18, mounting holes 19 for connecting the vehicle bodies respectively penetrate in the axial direction. Further, a stepped portion 20 that is bent toward the inner peripheral side is integrally formed at the lower end portion of the holder portion 16.

  The apparatus main body 12 is provided with a thin cylindrical outer cylinder 24 having both axial ends opened on the outer peripheral side thereof, and a mounting bracket 26 formed in a substantially columnar shape on the inner peripheral side of the outer cylinder 24. It is arranged substantially coaxially. A stepped portion 28 that is bent toward the inner peripheral side is formed at the lower end portion of the outer cylinder 24, and a small diameter portion 30 that has a smaller diameter than the upper side is integrally formed through the stepped portion 28. Is formed. The outer cylinder 24 is fitted into the holder portion 16 so that the stepped portion 28 contacts the stepped portion 20 of the holder portion 16. At this time, the entire holder part 16 or the vicinity of the upper end part is caulked to the inner peripheral side, whereby the apparatus main body 12 including the outer cylinder 24 is fixed at a predetermined position in the bracket 14.

  Here, when connecting the vibration isolator 10 to the vehicle body side, bolts (not shown) are respectively inserted into the mounting holes 19 of the pair of leg portions 18 and the tip portions thereof are inserted into the bolt holes provided on the vehicle body side. By screwing, the vibration isolator 10 is fastened and fixed to the vehicle body via the bracket 14. Further, a bolt shaft 32 that protrudes upward along the axis S is provided on the upper surface of the mounting bracket 26, and the mounting bracket 26 is connected and fixed to the engine side of the vehicle via the bolt shaft 32. The

  In the vibration isolator 10, a rubber covering portion 34 formed in a thin film shape is vulcanized and bonded to the inner peripheral surface of the outer cylinder 24, and a rubber made portion is closed so that the lower end side in the small diameter portion 30 is closed. A diaphragm 36 is integrally formed with the covering portion 34. The diaphragm 36 is formed in a bowl shape that is convexly convex upward, and expands or contracts the internal volume of the sub liquid chamber 72 in accordance with a pressure change of the liquid filled in the sub liquid chamber 72 described later. It can be elastically deformed along the axial direction.

  In the vibration isolator 10, a spacer member 38, a first partition member 40, a second partition member 42, and an intermediate cylinder 44 are respectively inserted into the inner peripheral side of the outer cylinder 24 from the lower end side toward the upper end side. Yes. The vibration isolator 10 is provided with a rubber elastic body 22 made of rubber between the intermediate cylinder 44 and the mounting bracket 26. The rubber elastic body 22 is formed in a substantially thick cylindrical shape as a whole, and its inner peripheral surface and outer peripheral surface are vulcanized and bonded to the inner peripheral surface of the intermediate tube 44 and the outer peripheral surface of the mounting bracket 26, respectively. . Thereby, the mounting bracket 26 and the intermediate cylinder 44 are elastically connected by the rubber elastic body 22.

  The spacer member 38 is formed in a thin cylindrical shape having an outer diameter corresponding to the inner diameter of the outer cylinder 24, and is fitted into the inner peripheral side of the outer cylinder 24 through the covering portion 34, and the lower end portion thereof is the outer cylinder. It is abutted against the 24 step portions 28. A first partition member 40 is fitted into the outer cylinder 24 above the spacer member 38. The first partition member 40 is formed in a disc shape whose inner peripheral side is thicker than the outer peripheral side, and a flange-like extension portion 50 extending to the outer peripheral side is formed at the lower end portion of the outer peripheral surface. It is integrally formed. The first partition member 40 is an orifice forming portion 52 having a thick disk shape on the inner peripheral side, and an annular groove portion is formed on the upper surface portion of the orifice forming portion 52 along the circumferential direction centering on the axis S. 54 is formed over nearly one circumference. A communication hole 56 that penetrates to the lower surface of the orifice forming portion 52 is formed in one end portion of the groove portion 54.

  In the orifice forming portion 52, a circular recess 58 is formed on the inner peripheral side of the groove portion 54, and a plurality of openings 60 penetrating to the lower surface of the orifice forming portion 52 are formed in the bottom plate portion of the recess 58. ing. The first partition member 40 is provided with a disc-shaped closing plate 62 fixed to the upper surface portion of the orifice forming portion 52, and the closing plate 62 is closed from the upper surface side of the groove portion 54 and the storage chamber 70. In this way, it is fixed to the orifice forming portion 52 by bonding, screwing or the like. The stop plate 62 has a communication hole 64 formed at a portion facing the other end of the groove portion 54, and a plurality of openings 65 formed at a portion facing the recess 58.

  Here, the communication hole 56 and the groove 54 in the orifice forming part 52 and the communication hole 64 of the closing plate 62 define a first orifice 66 that is a restricting passage for communicating a first pressure receiving liquid chamber 76 and a sub liquid chamber 72 described later. Forming. Further, the recess 58 of the orifice forming portion 52 whose upper surface is closed by the closing plate 62 is configured as a storage chamber 70 for storing the movable plate 68 made of rubber. The movable plate 68 is formed in a disk shape with a constant thickness, the thickness of which is shorter than the width along the axial direction of the storage chamber 70 by a predetermined length, and the outer diameter is smaller than the inner diameter of the storage chamber 70. Also slightly shorter. Thereby, the movable plate 68 can move (vibrate) along the axial direction within the range of the difference between the thickness of the movable plate 68 and the thickness of the storage chamber 70.

  The first partition member 40 makes the lower surface outer peripheral portion of the extending portion 50 abut on the upper end portion of the spacer member 38. As a result, a space partitioned from the outside by the diaphragm 36 and the first partition member 40 is formed on the lower side in the outer cylinder 24, and this space is filled with a liquid such as ethylene glycol or silicon oil. 72.

  On the other hand, a concave portion 74 having a substantially frustoconical cross section along the axial direction is formed in the central portion of the lower surface of the rubber elastic body 22, and an orifice forming portion 52 is formed in the concave portion 74 from the lower surface side. Has been inserted. Further, the extended portion 50 of the first partition member 40 is in pressure contact with the peripheral edge of the recess 58 on the lower surface of the rubber elastic body 22 over the entire circumference. Thereby, the first partition member 40 closes the lower surface side in the recess 74 and forms a space partitioned from the outside in the recess 74. This space is a first pressure receiving liquid chamber 76 filled with a liquid such as ethylene glycol or silicon oil. The first pressure receiving liquid chamber 76 and the sub liquid chamber 72 communicate with each other through the first orifice 66 of the orifice forming portion 52, and the first pressure receiving liquid chamber 76 and the sub liquid chamber 72 pass through the first orifice 66. Then liquids can circulate each other. Here, the 1st orifice 66 is tuned so that the path length and cross-sectional area may adapt to the shake vibration (for example, frequency is 8-12 Hz) which is a low frequency vibration.

  A second partition member 42 is fitted into the outer cylinder 24 on the upper side of the extending portion 50 of the first partition member 40. As shown in FIGS. 2 and 3, the second partition member 42 is formed in a thick cylindrical shape, and its outer diameter is a dimension corresponding to the inner diameter of the outer cylinder 24. As shown in FIG. 1, the second partition member 42 inserted and inserted into the outer cylinder 24 abuts its lower surface portion on the upper surface side of the extended portion 50 of the first partition member 40, and the covering portion 34. The outer peripheral surface is brought into pressure contact with the inner peripheral surface of the outer cylinder 24.

  As shown in FIGS. 3 (B), (C) and (D), the second partition member 42 has a first crank so as to extend in the form of a crank over the outer circumferential surface of the second partition member 42. An outer circumferential groove 80 is formed, and a first outer circumferential groove 82 is formed so as to extend in a crank shape over almost half a circumference even at a portion 180 degrees out of phase with the first outer circumferential groove 80. ing. As shown in FIGS. 3A, 3C, and 3E, the second partition member 42 is substantially ½ at a portion that is 90 ° out of phase with the first outer circumferential groove 80 on the outer circumferential surface. A second outer circumferential groove 84 is formed so as to extend in a crank shape over the circumference, and a crank shape is provided over a nearly ½ circumference at a portion that is 180 ° out of phase with the second outer circumferential groove 84. A second outer peripheral groove 86 is formed so as to extend in the vertical direction.

  As shown in FIG. 3, the first outer circumferential groove 80 and the first outer circumferential groove 82 are respectively formed with an upper communication port 87 and an upper communication port 88 penetrating to the upper surface of the second partition member 42 at one end thereof. At the other end, a lower communication port 90 and a lower communication port 92 that penetrate to the lower surface of the second partition member 42 are formed. The second outer circumferential groove 84 and the second outer circumferential groove 86 are also formed with an upper communication port 94 and an upper communication port 96 penetrating to the upper surface of the second partition member 42 at one end thereof, respectively, A lower communication port 98 and a lower communication port 100 penetrating to the lower surface of the two partition member 42 are formed.

  As shown in FIGS. 3A, 3 </ b> B, 3 </ b> D, and 3 </ b> E, the extended portion 50 of the first partition member 40 has a lower portion at a portion that faces the lower communication ports 90 and 92. The side notches 102 and 104 are formed, and the lower notches 106 and 108 are formed at portions facing the lower communication ports 98 and 100, respectively. The lower notches 102 and 104 communicate the lower communication ports 90 and 92 with the auxiliary liquid chamber 72, respectively, and the lower notches 106 and 108 communicate the lower communication ports 98 and 100 with the auxiliary liquid chamber 72, respectively. I am letting.

  As shown in FIG. 1, the intermediate cylinder 44 has a large-diameter cylindrical large-diameter portion 110 formed on the upper side, and extends from the lower end of the large-diameter portion 110 to the inner peripheral side on the lower side. A cylindrical small-diameter portion 114 having a smaller diameter than the large-diameter portion 110 is integrally formed through a stepped portion 112. Here, the large diameter portion 110 has an outer diameter corresponding to the inner diameter of the outer cylinder 24, and the small diameter portion 114 has an outer diameter corresponding to the inner diameter of the second partition member 42. The intermediate cylinder 44 abuts the outer peripheral surface of the small-diameter portion 114 on the inner peripheral surface of the second partition member 42, and the outer peripheral surface of the large-diameter portion 110 is connected to the upper end portion of the inner peripheral surface of the outer cylinder 24 via the covering portion 34. Pressure contact. In addition, the intermediate cylinder 44 makes the stepped portion 112 abut on the upper surface portion of the second partition member 42. Accordingly, the second partition member 42 is sandwiched between the stepped portion 112 and the extending portion 50 of the first partition member 40, and the movement in the axial direction is restricted.

  As shown in FIGS. 3A, 3 </ b> B, 3 </ b> D, and 3 </ b> E, the stepped portion 112 of the intermediate cylinder 44 faces the upper communication ports 87 and 88, respectively, and the upper notch portions 140 and 142. Are formed, and upper cutout portions 144 and 146 are formed facing the upper communication ports 94 and 96, respectively. The upper notches 140 and 142 allow the upper communication ports 87 and 88 to communicate with second pressure receiving liquid chambers 132A and 132B, which will be described later, and the upper notches 144 and 146 respectively connect the upper communication ports 94 and 96 to the later description. The third pressure receiving liquid chambers 136A and 136B communicate with each other.

  As shown in FIG. 4, the rubber elastic body 22 has a pair of first cavities 116 and 118 and a pair of second cavities 120 and 122 in the inner peripheral side portion of the large diameter portion 110 in the intermediate cylinder 44. It is formed in a concave shape from the outer peripheral side toward the inner peripheral side. Here, the pair of first cavities 116 and 118 are arranged so as to sandwich the mounting bracket 26 along the first sub-amplitude direction (arrow H1 direction) which is a radial direction orthogonal to the axial direction. The pair of second cavities 120 and 122 are disposed so as to sandwich the mounting bracket 26 along the second sub-amplitude direction (arrow H2 direction) orthogonal to the axial direction and the first sub-amplitude direction. As shown in FIG. 1, the pair of first cavities 116 and 118 have a substantially V-shaped cross-sectional shape that decreases in width from the outer peripheral side toward the inner peripheral side. The pair of second cavities 120 and 122 also have a cross-sectional shape along the axial direction substantially the same as the cross-sectional shape of the pair of first cavities 116 and 118.

  As shown in FIG. 4, the pair of first cavities 116 and 118 and the pair of second cavities 120 and 122 each have a cross-sectional shape along the radial direction that is wider from the inner peripheral side to the outer peripheral side. The rubber elastic body 22 has a substantially fan-like shape that is wide between the first cavity 116 and 118 and the second cavity 120 and 122 from the inner circumference side toward the outer circumference side. Four partition wall portions 124, 125, 126, and 127 having the cross section are formed. The outer peripheral surfaces of these partition wall portions 124, 125, 126, and 127 are fixed to the inner peripheral surface of the large diameter portion 110 by vulcanization adhesion. In addition, the large-diameter portion 110 of the intermediate cylinder 44 has a first opening 128 and a second opening 130 that are substantially rectangular and face the pair of first cavities 116 and 118 and the second cavities 120 and 122, respectively. Is formed.

  The pair of first cavities 116, 118 and the pair of second cavities 120, 122 are each closed on the outer peripheral side by the inner peripheral surface of the outer cylinder 24 via the covering portion 34. Thereby, spaces partitioned from the outside are formed in the pair of first cavities 116 and 118 and the pair of second cavities 120 and 122, respectively. Are the second pressure receiving liquid chambers 132A and 132B filled with a liquid such as ethylene glycol and silicone oil, and the spaces in the pair of second cavities 120 and 122 are respectively ethylene glycol and silicone oil. The third pressure receiving liquid chambers 136A and 136B are filled with the liquid.

  Here, as shown in FIG. 1, the pair of first outer peripheral grooves 80, 82 (see FIG. 3) in the second partition member 42 is formed on the outer peripheral side of the inner peripheral surface of the outer cylinder 24 via the covering portion 34. Blocked. The pair of first outer peripheral grooves 80 and 82 whose outer peripheral sides are closed constitute second orifices 134A and 134B for communicating the pair of second pressure receiving liquid chambers 132A and 132B with the sub liquid chamber 72, respectively. The pair of second outer peripheral grooves 84 and 86 (see FIG. 3) in the second partition member 42 are also closed on the outer peripheral side by the inner peripheral surface of the outer cylinder 24 via the covering portion 34. The pair of second outer peripheral grooves 84 and 86 whose outer peripheral sides are closed constitute third orifices 138A and 138B that allow the pair of third pressure receiving liquid chambers 136A and 136B to communicate with the sub liquid chamber 72, respectively. These second orifices 134A, 134B and third orifices 138A, 138B are tuned so that their path lengths and cross-sectional areas are adapted to vibrations of slightly lower frequencies (eg, 6 to 10 Hz) than shake vibrations. .

  In the vibration isolator 10 configured as described above, the rubber elastic body 22 is arranged in the direction in which the second pressure receiving liquid chamber 132B is arranged via the mounting bracket 26 (first sub-amplitude direction, arrow H1 direction in FIG. 4). When elastically deforming, the internal volumes of the second pressure receiving fluid chamber 132A and the second pressure receiving fluid chamber 132B mainly expand and contract. Further, in the vibration isolator 10, the rubber elastic body 22 is arranged in the direction in which the third pressure receiving liquid chamber 136A and the third pressure receiving liquid chamber 136B are arranged via the mounting bracket 26 (second sub-amplitude direction, arrow H2 direction in FIG. 4). When elastically deformed, the internal volumes of the third pressure receiving fluid chamber 136A and the third pressure receiving fluid chamber 136B mainly expand and contract, respectively. In the vibration isolator 10 of the present embodiment, the first sub-amplitude direction substantially coincides with the vehicle front-rear direction when the engine mount is mounted on the vehicle, and the second sub-amplitude direction is described later on the vehicle. The mounting direction is set so as to substantially coincide with the sub-amplitude direction.

  In the vibration isolator 10, the spacer member 38, the first partition member 40, the second partition member 42, and the mounting bracket 26 and the intermediate cylinder 44 connected by the rubber elastic body 22 are inserted into predetermined positions in the outer cylinder 24. The spacer member 38, the first partition member 40, the second partition member 42, and the intermediate tube 44 are fixed in the outer tube 24 by caulking the entire outer tube 24 toward the inner peripheral side. As a result, the assembly of the apparatus main body 12 is completed, and the apparatus main body 12 is inserted into the holder portion 16 of the bracket 14 as described above, and is fixed to the bracket 14 by caulking the holder portion 16 toward the inner peripheral side. Is done.

  Next, the operation of the vibration isolator 10 according to the present embodiment configured as described above will be described. In the vibration isolator 10, when the engine connected to the mounting bracket 26 operates, vibration from the engine is transmitted to the rubber elastic body 22 via the mounting bracket 26. At this time, the rubber elastic body 22 acts as a vibration absorber, and the input vibration is absorbed by a damping action due to internal friction or the like accompanying the deformation of the rubber elastic body 22.

  At this time, main vibrations input from the engine include vibrations (main vibrations) generated by the reciprocating movement of pistons in the engine within the cylinders, and vibrations generated by changes in the rotational speed of the crankshaft in the engine. (Sub-vibration). When the engine is a series type, the main vibration has an amplitude direction (main amplitude direction) that substantially coincides with the vertical direction of the vehicle, and the sub-vibration has an amplitude direction in which the series engine is placed horizontally. In this case, it is the longitudinal direction of the vehicle (first sub-amplitude direction) orthogonal to the amplitude direction of the main vibration, and substantially coincides with the left-right direction of the vehicle (second sub-amplitude direction) when the series engine is installed vertically. Become a thing. Here, the rubber elastic body 22 has an internal friction or the like regardless of whether the input vibration is a main vibration along the main amplitude direction or a sub vibration along the first sub-amplitude direction or the second sub-amplitude direction. It can be absorbed by the damping action.

  In the vibration isolator 10, the first pressure receiving liquid chamber 76 is disposed on the inner peripheral side of the outer cylinder 24 and on the lower side in the axial direction of the mounting bracket 26, and the first pressure receiving liquid chamber 76 is the first. By communicating with the auxiliary liquid chamber 72 through the orifice 66, when the main vibration along the axial direction (main amplitude direction) is input from the engine side to the mounting bracket 26, the rubber elastic body 22 is elastically deformed along the main amplitude direction. At the same time, since the internal volume of the first pressure receiving liquid chamber 76 is expanded and contracted, the liquid flows through the first pressure receiving liquid chamber 76 and the sub liquid chamber 72 through the first orifice 66. As a result, according to the vibration isolator 10, since the path length and the cross-sectional area of the first orifice 66 are set (tuned) to match the shake vibration, when the main vibration is the shake vibration, A resonance phenomenon (liquid column resonance) occurs in the liquid flowing between the first pressure receiving liquid chamber 76 and the sub liquid chamber 72 through the first orifice 66 in synchronization with the input vibration. Shake vibration input along the main amplitude direction can be absorbed particularly effectively by the pressure change and viscous resistance of the liquid.

  In the vibration isolator 10, when the frequency of the main vibration to be input is higher than the frequency of the shake vibration and the amplitude is small, for example, the input vibration is idle vibration (for example, 20 to 30 Hz) and the amplitude is 0.1 mm. In the case of about ˜0.2 mm, the first orifice 66 tuned to match the shake vibration is clogged, and it is difficult for the liquid to flow through the first orifice 66, but the movable plate 68 is accommodated in the storage chamber 70. The first pressure receiving liquid chamber 76 and the auxiliary liquid chamber pass through the gap between the inner wall surface of the storage chamber 70 and the movable plate 68 and the openings 60 and 65 by vibrating in the axial direction in synchronization with the input vibration. Since the liquid flows between the first and second pressure receiving liquid chambers 76, the increase in the dynamic spring constant accompanying the increase in the hydraulic pressure in the first pressure receiving liquid chamber 76 can be suppressed. Spring constant Ku maintained, high-frequency vibration can be effectively absorbed by the rubber elastic body 22.

  Further, in the vibration isolator 10, the pair of second pressure receiving liquid chambers 132A and 132B are arranged on the inner peripheral side of the first mounting member so that the mounting bracket 26 is sandwiched along the first sub-amplitude direction orthogonal to the main amplitude direction. The pair of second pressure receiving fluid chambers 132A and 132B communicate with the auxiliary fluid chamber 72 through the pair of second orifices 134A and 134B, respectively, so that the outer cylinder 24 or the mounting bracket 26 is connected to the front and rear of the vehicle from the engine side. When vibration along the direction (first sub-amplitude direction) is input, the rubber elastic body 22 is elastically deformed along the first sub-amplitude direction, and the rubber elastic body 22 mainly includes the pair of second pressure receiving liquid chambers 132A, Since the internal volume of 132B is expanded and contracted, the space between the pair of second pressure receiving liquid chambers 132A and 132B and the sub liquid chamber 72 is respectively passed through the pair of second orifices 134A and 134B. Body flows with each other. At this time, the path length and the cross-sectional area of the two second orifices 134A and 134B are tuned so as to be compatible with low-frequency vibration (for example, 6 Hz to 10 Hz), so that the input secondary vibration is low-frequency vibration. In this case, in synchronization with the input sub-vibration, resonance occurs with the liquid flowing between the two second pressure receiving liquid chambers 132A and 132B and the sub liquid chamber 72 through the two second orifices 134A and 134B. Since a phenomenon (liquid column resonance) occurs, low-frequency vibrations input along the sub-amplitude direction can be particularly effectively absorbed by a change in pressure of the liquid accompanying the liquid column resonance, viscous resistance, and the like.

  Here, since the two second pressure receiving liquid chambers 132A and 132B are arranged in the outer cylinder 24 so as to sandwich the mounting bracket 26 in the first sub-amplitude direction, the mounting bracket 26 and the outer cylinder 24 are arranged. As compared with the case where only one second pressure receiving liquid chamber is provided between the first and second pressure chambers, the damping force obtained by the liquid column resonance with respect to the vibration input along the first sub-amplitude direction can be increased approximately twice. Therefore, it is possible to efficiently attenuate and absorb the vibration input along the first sub-amplitude direction.

  In the vibration isolator 10 according to the present embodiment, both the second orifice 134A and the second orifice 134B are tuned so as to conform to a common vibration frequency range (for example, 6 Hz to 10 Hz). The vibration frequency to which the second orifice 134A is adapted may be different from the vibration frequency to which the other second orifice 134B is adapted.

  Further, in the vibration isolator 10, the outer cylinder 24 is arranged such that the pair of third pressure receiving liquid chambers 136A and 136B sandwich the mounting bracket 26 along the main amplitude direction and the second sub-amplitude direction orthogonal to the first sub-amplitude direction. The pair of third pressure receiving liquid chambers 136A and 136B communicate with the auxiliary liquid chamber 72 through the pair of third orifices 138A and 138B, respectively, so that the vehicle is connected to the outer cylinder 24 or the mounting bracket 26. When vibration along the left-right direction (second sub-amplitude direction) is input, the rubber elastic body 22 is elastically deformed along the second sub-amplitude direction, and the rubber elastic body 22 mainly includes a pair of third pressure receiving liquid chambers 136A, Since the internal volume of 136B is expanded and contracted, the liquid flows between the pair of third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72 through the pair of third orifices 138A and 138B. Each other to distribution. At this time, the path length and the cross-sectional area of the two third orifices 138A and 138B are tuned so as to be compatible with low-frequency vibration (for example, 6 Hz to 10 Hz), so the input secondary vibration is low-frequency vibration. In this case, a resonance phenomenon occurs in the liquid flowing between the two third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72 through the two third orifices 138A and 138B in synchronization with the input sub vibration. (Liquid column resonance) occurs, and therefore, low-frequency vibrations input along the second sub-amplitude direction can be particularly effectively absorbed by the pressure change of the liquid accompanying the liquid column resonance, viscous resistance, and the like.

  Here, since the two third pressure receiving liquid chambers 136A and 136B are arranged in the outer cylinder 24 so as to sandwich the mounting bracket 26 along the second sub-amplitude direction, the mounting bracket 26 and the outer cylinder 24 are arranged. As compared with the case where only one third pressure receiving liquid chamber is provided between the two, the damping force obtained by the liquid column resonance with respect to the vibration input along the second sub-amplitude direction can be approximately doubled. The vibration input along the second sub-amplitude direction can be efficiently attenuated and absorbed.

  In the vibration isolator 10 according to the present embodiment, both the third orifice 138A and the third orifice 138B are tuned so as to conform to a common vibration frequency range (for example, 6 Hz to 10 Hz). The vibration frequency region in which the third orifice 138A is compatible may be different from the vibration frequency region in which the other third orifice 138B is compatible.

  As described above, according to the vibration isolator 10 according to the present embodiment, the first pressure receiving liquid chamber 76 and the sub liquid chamber 72 are passed through the first orifice 66 when inputting vibration along the vehicle vertical direction (main amplitude direction). The vibration along the main amplitude direction can be efficiently absorbed by the liquid column resonance between the two and the two second orifices when the vibration along the vehicle longitudinal direction (first sub-amplitude direction) is input. The liquid column resonance occurs between the two second pressure receiving liquid chambers 132A and 132B and the sub liquid chamber 72 through 134A and 134B, so that vibration along the first sub amplitude direction can be efficiently absorbed, and the vehicle left and right When the vibration along the direction (second sub-amplitude direction) is input, liquid column resonance occurs between the two third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72 through the two third orifices 138A and 138B. The second side vibration Vibration along the direction can be efficiently absorbed.

  In the vibration isolator 10, the internal volume of the second pressure receiving liquid chambers 132A and 132B and the internal volume of the third pressure receiving liquid chambers 136A and 136B are also deformed by the deformation of the rubber elastic body 22 even when vibrations along the main amplitude direction are input. , The liquid resonance also occurs between the second pressure receiving liquid chambers 132A and 132B, the third pressure receiving liquid chambers 136A and 136B, and the sub liquid chamber 72. A damping force is obtained in a frequency range different from the damping force obtained by the liquid column resonance between the pressure receiving liquid chamber 76 and the sub liquid chamber 72.

  Similarly, in the vibration isolator 10, when the vibration along the first sub-amplitude direction is input, the internal volumes of the third pressure receiving fluid chambers 136A and 136B are incidentally expanded and contracted due to the deformation of the rubber elastic body 22. Since liquid resonance also occurs between the third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72, this liquid column resonance is obtained by liquid column resonance between the second pressure receiving liquid chambers 132A and 132B and the sub liquid chamber 72. The damping force is obtained in a frequency range different from the damping force to be generated, and the internal volume of the second pressure receiving liquid chambers 132A and 132B is accompanied by deformation of the rubber elastic body 22 even when vibration is input along the second sub-amplitude direction. As a result of the expansion and contraction, liquid resonance occurs between the third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72, and the third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72 are also affected by this liquid column resonance. Obtained by liquid column resonance between That the damping force at a different frequency range is obtained and the damping force.

  Further, in the vibration isolator 10, the second pressure receiving liquid chambers 132A and 132B, the third pressure receiving liquid chambers 136A and 136B, and the auxiliary liquid chamber 72 are partitioned on the inner peripheral side of the outer cylinder 24, and the second orifices 134A and 134B. And the second partition member 42 in which the third orifices 138A and 138B are formed, the interval between the second pressure receiving liquid chambers 132A and 132B and the third pressure receiving liquid chambers 136A and 136B and the sub liquid chamber 72 is provided. Can be made sufficiently wide as necessary, and the path lengths of the second orifices 134A and 134B and the path lengths of the third orifices 138A and 138B can be made sufficiently long. Compared with the case where a plurality of liquid chambers are provided and orifices communicating with these liquid chambers are formed in a rubber elastic body, the second orientation is suppressed while suppressing the expansion of the apparatus size. Scan 134A, the path length of 134B, and a third orifice 138A, respectively low frequencies the path length of 138B (e.g., 6Hz～20Hz below) can be easily tuned to fit the vibration of.

  In the vibration isolator 10 according to the present embodiment, the outer cylinder 24 is connected to the vehicle body side via the bracket 14 and the mounting bracket 26 is connected to the engine side. 24 may be connected to the engine side, and the mounting bracket 26 may be connected to the vehicle body side.

It is side surface sectional drawing which shows the structure of the vibration isolator which concerns on embodiment of this invention. It is a perspective view which shows the structure of the 2nd partition member in a vibration isolator as FIG. 1 shows. (A), (B), (D) and (E) are side views of the second partition member shown in FIG. 1 as viewed from different angles by 90 °, and (C) is the second partition member shown in FIG. FIG. It is sectional drawing along the IV-IV cutting line of the apparatus main body shown by FIG.

Explanation of symbols

10 Vibration isolator 22 Rubber elastic body 24 Outer cylinder (first mounting member)
26 Mounting bracket (second mounting member)
36 Diaphragm 42 Second partition member (partition member)
52 Orifice formation portion 66 First orifice (first restriction passage)
72 Sub liquid chamber 76 First pressure liquid chamber 132A, 132B Second pressure liquid chamber 134A, 134B Second orifice (second restriction passage)
136A, 136B Third pressure receiving liquid chamber 138A, 138B Third orifice (third restricted passage)

Claims (5)

A first mounting member connected to one of the vibration generating portion and the vibration receiving portion and formed in a substantially cylindrical shape;
A second mounting member connected to the other of the vibration generating unit and the vibration receiving unit and disposed on the inner peripheral side of the first mounting member;
A rubber elastic body disposed between the first mounting member and the second mounting member and elastically connecting the first mounting member and the second mounting member;
A first pressure receiving liquid chamber that is provided on the inner peripheral side of the first mounting member and outside the second mounting member in the axial direction , and at least a part of the inner wall is formed of the elastic body and filled with liquid. When,
A sub liquid chamber in which a part of the partition wall is formed by a diaphragm and the internal volume can be expanded and contracted in accordance with a change in liquid pressure, while being filled with liquid;
A first restriction passage for communicating the first pressure receiving liquid chamber and the sub liquid chamber with each other;
It is provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member along a first sub-amplitude direction orthogonal to the axial direction, and at least a part of the inner wall is formed by the elastic body. A pair of second pressure receiving liquid chambers filled with liquid;
A pair of second restriction passages that respectively connect the pair of second pressure receiving liquid chambers to the sub liquid chamber;
At least one of the inner walls is provided on the inner peripheral side of the first mounting member so as to sandwich the second mounting member along the second sub-amplitude direction orthogonal to the axial direction and the first sub-amplitude direction. A pair of third pressure receiving liquid chambers formed of the elastic body and filled with a liquid;
A pair of third restriction passages that respectively connect the pair of third pressure receiving liquid chambers to the sub liquid chamber;
An anti-vibration device comprising:   A plurality of second pressure receiving liquid chambers and sub liquid chambers are partitioned on the inner peripheral side of the first mounting member, and partition members each having the second restriction passage and the third restriction passage are formed. The anti-vibration device according to claim 1, wherein the anti-vibration device is provided.   When the elastic body is elastically deformed by vibration input along the main amplitude direction substantially coincident with the axial direction to the first mounting member or the second mounting member, the elastic body is mainly subjected to elastic deformation along the main amplitude direction. The vibration isolator according to claim 1 or 2, wherein the internal volume of the first pressure receiving liquid chamber is expanded or reduced.   When the elastic body is elastically deformed by an input of vibration along the first sub-amplitude direction to the first mounting member or the second mounting member, the elastic body mainly receives the first deformation due to elastic deformation along the first sub-amplitude direction. The vibration isolator according to any one of claims 1 to 3, wherein the internal volume of the two pressure receiving liquid chambers is expanded or reduced.   When the elastic body is elastically deformed by the vibration input along the second sub-amplitude direction to the first mounting member or the second mounting member, the elastic body mainly receives the first deformation due to the elastic deformation along the second sub-amplitude direction. 5. The vibration isolator according to claim 1, wherein the internal volume of the pressure receiving liquid chamber is expanded or reduced.

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