JP4718500B2

JP4718500B2 - Liquid-filled vibration isolator

Info

Publication number: JP4718500B2
Application number: JP2007042973A
Authority: JP
Inventors: 洋徳加藤; 彦文山本
Original assignee: 東洋ゴム工業株式会社
Priority date: 2007-02-22
Filing date: 2007-02-22
Publication date: 2011-07-06
Anticipated expiration: 2027-02-22
Also published as: JP2008202765A

Description

The present invention relates to a liquid-filled vibration isolator that is mainly used for vibration-proof support of an automobile engine or the like.

Conventionally, as this type of liquid-filled vibration isolator, a first mounting tool, a cylindrical second mounting tool, a vibration isolating base made of a rubber-like elastic body that connects them, and the second mounting tool are attached. A diaphragm that forms a liquid enclosure between the anti-vibration base, a partition that divides the liquid enclosure into a first liquid chamber on the anti-vibration base and a second liquid chamber on the diaphragm, and both liquid chambers An annular orifice forming member that is provided inside the peripheral wall portion of the second fixture and forms the orifice, and the first liquid chamber and the first inside the orifice forming member. 2. Description of the Related Art An elastic partition membrane that partitions the two liquid chambers in the axial direction and a pair of displacement regulating means that regulates the displacement amount of the elastic partition membrane from both sides of the membrane surface are known (for example, the following) Patent Literatures 1 to 3).

In this vibration isolator, when vibration with a large amplitude occurs due to unevenness of the traveling road surface, the liquid flows between the liquid chambers through the orifice, and the vibration is attenuated by the liquid flow effect. On the other hand, when vibration with a small amplitude such as idling vibration occurs, the orifice does not function, and the elastic partition membrane is reciprocated to absorb the fluid pressure fluctuation between the two fluid chambers, thereby obtaining a low dynamic spring characteristic. It is done.

In such a liquid filled type vibration isolator, abnormal noise caused by the collision of the elastic partition film with the displacement regulating means may be a problem. Therefore, in Patent Document 3 below, a so-called inverted type liquid in which the first fixture is a lower fixture that can be attached to the vehicle body side and the cylindrical second fixture is an upper fixture that can be attached to the engine side. By adopting the enclosed vibration isolator, a part of the vibration transmission path from the partition body to the vehicle body is constituted by the vibration isolating base, so that the vibration caused by the collision is absorbed by the vibration isolating base and the difference into the vehicle interior is obtained. The sound is reduced.

That is, conventionally, in this type of liquid-filled vibration isolator, generally, the cylindrical second mounting tool is a lower mounting tool that is mounted on the vehicle body side, and the first mounting tool is mounted on the engine side. Although it is used as a fixture (see, for example, Patent Document 2 below), it has been proposed to absorb vibrations caused by a collision generated in a partition body by a vibration-proof base by inverting it. In addition, a configuration in which the cylindrical mounting bracket is an upper mounting bracket that can be mounted on the engine side, and the lower mounting bracket that is mounted on the vehicle body side is the mounting bracket facing the cylindrical mounting bracket is disclosed in, for example, Patent Documents 1 and 4 below. Is also disclosed.
JP 07-238983 A JP 2003-294080 A JP 2006-083907 A Japanese Patent Laying-Open No. 2005-083461

In the inverted type liquid-filled vibration isolator as described above, not only the cylindrical upper fixture but also the liquid inside it is attached to the part that is coupled to the support side of the vehicle body or the like via the vibration isolating base. Even the chamber acts as a mass. That is, in the inverted type, the mass supported by the vibration isolation base is increased. Therefore, there is a problem that the resonance point shifts to the low frequency side and approaches the resonance point of the vehicle body, and abnormal noise is generated due to such resonance.

The present invention has been made in view of the above points, and reduces noise caused by the resonance while having a structure that reduces noise caused by the elastic partition membrane colliding with the displacement restricting means. An object of the present invention is to provide a liquid-sealed vibration isolator that can be used.

A liquid-filled vibration isolator according to the present invention includes a lower attachment attached to a support side, a cylindrical upper attachment attached to a vibration source side, and a rubber-like elastic body connecting them. A diaphragm which is attached to the upper fixture and forms a liquid sealing chamber between the vibration isolating base, a first liquid chamber on the vibration isolating base, and a second liquid on the diaphragm side. A partition for partitioning the chamber, and an orifice for communicating the first liquid chamber and the second liquid chamber,
The partition body is provided inside the peripheral wall portion of the upper fixture to form an annular orifice forming member that forms the orifice, and the first liquid chamber and the second liquid chamber are axially arranged inside the orifice forming member. A liquid-filled vibration isolator comprising: an elastic partition membrane partitioning in a direction; and a pair of displacement regulating means for regulating a displacement amount of the elastic partition membrane from both sides of the membrane surface,
A first bracket for attaching the lower attachment to the support side; and a second bracket for attaching the upper attachment to the vibration source side;
The second bracket includes a cylindrical holding portion into which the upper fixture is press-fitted in the axial direction, a vibration source side fixing portion for fixing the upper mounting tool to the vibration source side, and the cylindrical holding portion and the vibration source side fixing. And a notch that is concave in the axial direction in the circumferential portion on the opposite side of the coupling portion of the cylindrical holding portion, and the axial direction of the circumferential portion. Is formed with a narrow width.

According to the above configuration, the cylindrical fixture provided with the partition is the upper fixture that is attached to the vibration source side, and the fixture that is connected to the upper fixture via the vibration isolation base is provided on the support side. Since the lower fixture is attached, even if vibration occurs due to the elastic partition film colliding with the displacement restricting means in the partition, the vibration forms a part of the vibration transmission path to the support side. Since it is absorbed by the vibration-proof substrate, it is possible to suppress the generation of abnormal noise by suppressing the transmission of abnormal noise due to the collision to the support side.

Further, in the cylindrical holding portion of the second bracket that holds the cylindrical upper mounting tool, the notch portion is provided in the specific portion in the circumferential direction so as to cut the mass, so that the resonance can be performed without impairing other performance. The point can be shifted to the high frequency side, and the generation of noise due to approaching the resonance point of the vehicle body can be suppressed.

In the present invention, the first bracket includes a fastening surface portion to which a lower end surface of the lower fixture is fixed, and a pair of support side fixings that are positioned on both sides of the fastening surface portion and are fixed to the support side. And a pair of vertical wall portions provided on both sides of the cylindrical holding portion sandwiching the cylindrical holding portion, and upper ends of the pair of vertical wall portions above the cylindrical holding portion. An upper wall portion to be connected,
The fastening surface portion is provided with a concave groove extending in a direction perpendicular to the opposing direction of the pair of vertical wall portions, and a through hole penetrating in the axial direction is provided in the concave groove,
A fixed convex portion that slides and fits into the concave groove is provided on the lower end surface of the lower fixture, and the fixed convex portion engages with one groove wall surface of the concave groove. And having the other side surface in a straight shape that engages with the other groove wall surface of the concave groove, and the engagement between the one side surface and the other side surface and the one groove wall surface and the other groove wall surface. The rotation of the fixed convex portion is restricted by the above, and when the fixed convex portion is fastened and fixed to the fastening surface portion by a bolt inserted from below into the through-hole, the following effects are obtained. Is done.

That is, when assembling the liquid-filled vibration isolator, the upper fixture is press-fitted into the cylindrical holding portion of the second bracket, and then inserted from the side of the first bracket. At that time, the fixing convex part of the lower mounting tool is slid into the concave groove of the fastening surface part of the first bracket and fitted, and the bolt is inserted from below the fastening surface part to fix the fixing convex part of the lower mounting tool. Fasten and fix. At that time, since the fixed convex portion has straight both side surfaces that respectively engage with the groove wall surfaces on both sides of the concave groove, the engagement becomes a non-rotating state when tightening with a bolt, so that a special jig is used. Bolts can be tightened accurately without using a screw.

In the liquid-filled vibration isolator according to the present invention, the elastic partition membrane further includes a partition membrane main body, and an annular thick portion provided around the partition membrane main body so as to be thicker than the partition membrane main body. And consist of
The pair of displacement restricting means are spaced apart and opposed to the partition membrane main body in the axial direction so as to restrict displacement in the axial direction of the partition membrane main body, and the annular thick portion is the axial core. It consists of an annular support part that supports so as to be sandwiched from both sides of the direction,
Both side surfaces in the axial direction of the annular thick portion are formed as flat surfaces perpendicular to the axial direction, respectively, and the flat surfaces are provided to face the annular support portion over the entire radial direction, The distance between the pair of annular support portions opposed to each other in the axial direction is set to be larger than the thickness of the annular thick portion, so that one side surface in the axial direction of the annular thick portion and the one side A minute gap is provided between the one annular support portion facing the side surface and the other side surface in the axial direction of the annular thick portion and the other annular support portion facing the other side surface. A gap is provided between the outer circumferential surface of the annular thick portion and the inner circumferential surface of the orifice forming member. It is provided in between.

With this configuration , when large-amplitude vibration occurs, both side surfaces of the annular thick part provided at the peripheral edge of the elastic partition film are pressed against the annular support part of the displacement restricting means. At that time, since the annular thick part is thickened with respect to the partition membrane main body, the annular thick part is difficult to be deformed, and the side surface is formed on a flat surface without projections or protrusions. And the annular support portion are in contact with each other without any gap, so that the liquid flow between the two liquid chambers around the elastic partition membrane can be prevented, and the liquid flow effect by the orifice can be effectively exhibited. On the other hand, when a vibration with a small amplitude occurs, a liquid flow is generated between the two liquid chambers through the minute gap on both sides of the annular thick part of the elastic partition membrane and the gap extending in the axial direction connecting the minute gap. At this time, both side surfaces of the annular thick portion are formed as flat surfaces, and there are no protrusions or protrusions that obstruct the liquid flow, so that the liquid flow is effectively ensured. Therefore, in combination with the reciprocating displacement in the elastic partition membrane, particularly the partition membrane main body, excellent low dynamic spring characteristics can be exhibited. Further, in this case, since the annular thick part is not clamped in the axial direction and a gap is provided on both sides, there is a concern about the impact sound caused by the collision with the opposing annular support part. Since the upper fixture to which the partition is attached is connected to the vibration source side, the vibration caused by the hitting sound can be absorbed by the vibration-proof base.

In this case, it is preferable that a plurality of protrusions are provided on the membrane surface of the partition membrane main body in a region radially inward of the annular support portion of the displacement regulating means. By providing such a projection, it is possible to reduce the contact area between the partition membrane body of the elastic partition membrane and the restricting portion body of the displacement restricting means, and to reduce noise caused by the collision of the elastic partition film with the displacement restricting means. it can. In addition, since the protrusion is provided so as not to be applied to the annular support portion, it is possible to prevent the liquid flow between the two liquid chambers around the elastic partition film at the time of large amplitude vibration.

In this case, the elastic partition membrane has a circular shape when viewed in the axial direction, and the protrusions are arranged in a plurality of rings concentrically surrounding the radial center of the elastic partition membrane and arranged in parallel at equal intervals in the circumferential direction. In this case, the elastic partition film has no directionality in the circumferential direction. Therefore, even if the elastic partition film is not fixed in the circumferential direction and can be rotated, it is possible to effectively exhibit the noise reduction effect due to the protrusions on the restricting portion main body of the displacement restricting means.

As described above, according to the present invention, while reducing the abnormal noise caused by the elastic partition membrane colliding with the displacement restricting means, the resonance point of the vibration isolator is shifted to the high frequency side to resonate the vehicle body. Generation of abnormal noise due to approaching a point can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view of a liquid-filled vibration isolator 10 according to an embodiment of the present invention, FIG. 2 is a perspective view seen from the lower surface side, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, and FIG. 5 is a side view of the vibration isolator 10. As shown in FIG.

The liquid-filled vibration isolator 10 is an engine mount for supporting an automobile engine 2 with respect to a vehicle body 1, and includes a lower attachment 12 attached to the vehicle body 1 side and a cylindrical shape attached to the engine 2 side. An anti-vibration device body 11 including an upper mounting tool 14 and a vibration-proof base 16 made of a rubber-like elastic body for connecting them, and a vehicle body side bracket 70 for mounting the lower mounting tool 12 to the vehicle body 1 side. And an engine side bracket 72 for attaching the upper fixture 14 to the engine 2 side.

As shown in FIG. 6, the lower mounting tool 12 is a stepped columnar metal member disposed below the shaft core portion of the upper mounting tool 14, and a female screw portion 18 is provided at the lower end surface 12 </ b> A. The opening is provided. The upper fixture 14 is a stepped cylindrical metal fitting having a large-diameter cylindrical portion 20 on the lower side, a small-diameter cylindrical portion 22 on the upper side, and a step portion 24 that connects the two, and the lower end of the large-diameter cylindrical portion 20. An outward flange portion 21 that receives the lower end of the cylindrical holding portion 74 is extended. The anti-vibration base 16 is vulcanized and bonded to the outer peripheral surface of the lower fixture 12 and the inner peripheral surface of the large-diameter cylindrical portion 20 of the upper fixture 14, and from the large-diameter cylindrical portion 20 to the first fixture. It is formed in the shape of a truncated cone having a gradually smaller diameter toward the bottom.

A diaphragm 28 made of a rubber-like elastic film is attached to the upper end of the upper fixture 14 so as to form a liquid sealing chamber 26 between the upper vibration-proof base 16. The diaphragm 28 includes a reinforcing metal fitting 30 on the outer peripheral portion, and the reinforcing metal fitting 30 is fitted on the inner peripheral surface of the rubber layer 32 that is continuous from the vibration-proof base 16 provided on the inner peripheral surface of the second fixture 14. ing.

The liquid enclosure chamber 26 is partitioned by a partition 34 into a first liquid chamber 26A on the vibration-isolating base 16 side and a second liquid chamber 26B on the diaphragm 28 side, and both liquid chambers 26A and 26B are liquid channels. Communication is made through an orifice 36.

As shown in FIGS. 6 to 9, the partition body 34 is provided inside the peripheral wall portion 14 </ b> A of the upper fixture 14 to form an annular orifice forming member 38 that forms the orifice 36, and an inner side of the orifice forming member 38. An elastic partition film 40 for partitioning the first liquid chamber 26A and the second liquid chamber 26B in the axial direction X, and a pair of upper and lower displacement regulating means 42 for regulating the displacement amount of the elastic partition film 40 from both sides of the film surface, 44.

The orifice forming member 38 is a metal or resin annular member having an orifice forming groove 45 opened on the radially outer side K1. In this example, the orifice forming member 38 includes a main body cylinder portion 38A constituting the inner peripheral wall of the orifice 36, and an upper wall portion extending outward from the upper end of the main body cylinder portion 38A to constitute the upper wall of the orifice 36. 38B and a flat plate-like second member 48 having a lower wall portion 38C constituting the lower wall of the orifice 36, and the inner circumference of the rubber layer 32 of the upper fixture 14 is assembled. It is fitted on the surface.

As shown in FIGS. 11 and 12, the elastic partition membrane 40 is a plate-like rubber member having a circular shape when viewed in the axial direction. The elastic partition membrane 40 is more than the disc-like partition membrane body 50 and the partition membrane body 50. It consists of an annular thick portion 52 that is thick and is provided around the partition membrane body 50. The annular thick part 52 is provided over the entire circumferential direction by increasing the thickness on both sides in the axial direction X with respect to the inner partition membrane body 50 at the peripheral edge of the elastic partition membrane 40. Both side surfaces 52A and 52B in the axial direction X of the thick portion 52 are formed as flat surfaces perpendicular to the axial direction X, respectively.

The displacement restricting means 42 and 44 are opposed to the partition membrane main body 50 with a spacing in the axial direction X and restrict the displacement of the partition membrane main body 50 in the axial direction X, and the annular thick wall It consists of the annular support part 56 which supports the part 52 so that it may be inserted | pinched from the both sides of the axial direction X. FIG. In this example, the upper displacement restricting means 42 is integrally provided on the inner peripheral surface of the main body cylinder portion 38 </ b> A in the first member 46 of the orifice forming member 38. The lower displacement restricting means 44 is integrally provided inside the second member 48 of the orifice forming member 38. The displacement regulating means 42 and 44 may be formed separately from the orifice forming member 38.

The annular support portion 56 is formed in a narrow ring plate shape at the peripheral edge portions of the displacement regulating means 42 and 44. In this example, as shown in FIG. 7, the restricting portion main body 54 inside the annular support portion 56 is formed by a lattice extending in the radial direction and orthogonal to each other. Four fan-shaped openings 58 are provided in the circumferential direction. In addition, the shapes of the restricting portion main body 54 and the annular support portion 56 in the pair of displacement restricting means 42 and 44 are the same so as to overlap in the axial direction X.

As shown in FIG. 10, the distance D1 between the pair of upper and lower annular support portions 56, 56 facing in the axial direction X is set to be larger than the thickness D2 of the annular thick portion 52 disposed therebetween. Thus, a minute gap 60, between the both side surfaces 52A and 52B of the annular thick portion 52 and the opposing surfaces 56A and 56A of the pair of annular support portions 56 and 56 facing the side surfaces 52A and 52B, respectively. 60 is provided. The minute gap 60 is a gap that is sufficiently smaller than the thickness of the elastic partition membrane 40, and more specifically, a minute gap that is sufficiently narrower than the thickness D3 of the annular thick portion 52 with respect to the surface of the partition membrane body 50. is there.

These upper and lower minute gaps 60, 60 extend in the axial direction X, which is formed between the outer peripheral surface 52C of the annular thick portion 52 and the inner peripheral surface 38D of the main body cylindrical portion 38A of the orifice forming member 38. The gap 62 communicates. The gap 62 is provided over the entire circumference in the circumferential direction, and is formed by a minute gap similar to the minute gap 60.

As shown in FIGS. 11 and 12, on the membrane surface of the partition membrane main body 50, a plurality of spherical crown-shaped projections 64 are dispersed in a region radially inwardly K2 from the annular support portion 56 of the displacement regulating means 42, 44. Is provided. The protrusions 64 are juxtaposed in a plurality of ring shapes concentrically surrounding the radial center O of the elastic partition film 40. In this example, one protrusion 64 is provided at the radial center O so as to surround the protrusion 64 in a seven-circle shape. Further, the protrusions 64 are arranged at equal intervals in the circumferential direction in each ring-shaped row, and in this example, the intervals between the adjacent protrusions 64 are constant in all the ring-shaped rows. Has been. The interval between the protrusions 64 adjacent to each other in the circumferential direction is set to a dimension equal to or smaller than the width (diameter) of each protrusion 64.

As shown in FIG. 10, the protrusion height H of the protrusion 64 is set to be smaller than the above-mentioned increased thickness D3 of the annular thick portion 52, and the annular thick portion 52 is displaced by the displacement restricting means 42 when the amplitude is large. , 44 is advantageously contacted. The shape and arrangement of the protrusions 64 provided on the elastic partition film 40 are the same so as to overlap on both the front and back sides of the elastic partition film 40.

As shown in FIGS. 3 and 4 and FIGS. 14 to 17, the engine side bracket 72 includes a cylindrical holding portion 74 into which the upper fixture 14 is press-fitted in the axial direction X, and an engine side for fixing to the engine 2 side. The fixing part 76 is provided with a connecting part 78 connected to the cylindrical holding part 74 and the engine side fixing part 76.

The cylindrical holding portion 74 is provided so as to protrude laterally from the connecting portion 78, has a short cylindrical shape that is coaxial with the upper mounting tool 14, and has a tip-side periphery located on the opposite side of the connecting portion 78. The direction portion 74A is provided with a notch 79 having a concave shape in the axial direction X, thereby narrowing the width of the circumferential portion 74A in the axial direction X. That is, the cylindrical holding portion 74 is formed such that the width E1 at the circumferential portion 74A provided with the notch 79 is smaller than the width E2 at the other circumferential portion 74B (see FIG. 16). .

As shown in FIGS. 3 and 17, the cylindrical holding portion 74 includes a cylindrical press-fit holding portion 75 that externally holds the large-diameter cylindrical portion 20 of the upper fixture 14 at the lower end portion. The upper cylindrical portion 77 has a straight cylindrical shape whose outer peripheral surface is smaller in diameter than the press-fit holding portion 75, and has a tapered surface shape whose inner peripheral surface is smaller in diameter toward the upper side. In the cutout portion 79, the upper side of the cylindrical holding portion 74 is cut out so that the upper cylindrical portion 77 is removed and only the press-fit holding portion 75 is provided. In the opposing direction F of a pair of vertical wall portions 90, 90 described later of the vehicle body side bracket 70, the upper cylindrical portion 77 is secured with the width E2 on both sides opposed to the diameter direction, which will be described later. The stopper function via the stopper rubber member 104 is effectively exhibited.

The engine side fixing part 76 includes bolt holes 80 penetrating in the axial direction X, and is fastened and fixed to the engine 2 side by inserting bolts (not shown). 1 and 14, reference numeral 82 denotes a bolt hole for fixing an unillustrated auxiliary bracket for supplementing rigidity.

As shown in FIGS. 2, 4, 15, and 16, the connecting portion 78 is provided with a meat stealing portion 84 that is recessed from the lower surface side to reduce the mass of the engine-side bracket 72.

1-4, the vehicle body side bracket 70 is positioned on both sides of the fastening surface portion 86 to which the lower end surface 12A of the lower fixture 12 is fixed, and on both sides of the fastening surface portion 86, and is fixed to the vehicle body 1 side. A pair of vehicle body side fixing portions 88, 88 and a pair of vertical wall portions 90, 90 provided on both sides of the cylinder holding portion 74 with the cylindrical holding portion 74 rising from the vehicle body side fixing portions 88, 88 upward X1; An upper wall 92 that connects the upper ends 90A and 90A of the pair of vertical wall portions 90 and 90 in the upper part X1 of the cylindrical holding portion 74 is provided, and has a substantially square shape as a whole.

A concave groove 94 extending in a direction G perpendicular to the facing direction F of the pair of vertical wall portions 90, 90 is provided on the upper surface of the fastening surface portion 86. A through hole 98 penetrating in the axial direction X to be inserted is provided. On the lower end surface 12 </ b> A of the lower attachment tool 12, a fixed convex portion 100 that slides and fits into the concave groove 94 is projected downward. The fixed convex portion 100 has a horizontal cross-section track shape having straight (that is, planar) both side surfaces 100A and 100A that engage with opposing groove wall surfaces 94A and 94A of the concave groove 94, respectively (see FIG. 13). ), The female screw portion 18 is provided at the center of the fixed convex portion 100.

As for the pair of vehicle body side fixing portions 88, 88, two bolt holes 102 penetrating in the axial direction X are provided on one of them, and one bolt hole 102 is provided on the other, and a bolt (not shown) is provided. And is fastened and fixed to the vehicle body 1 side.

The vertical wall portion 90 is a portion for exerting a stopper action in the vehicle front-rear direction between the opposing cylindrical holding portions 74, and the cylindrical stopper rubber member 104 covered by the cylindrical holding portion 74 is provided. Through this, the stopper action is exhibited.

The upper wall portion 92 is a portion that exerts a stopper action that restricts the upward relative displacement of the vehicle body side bracket 70 between the upper ends of the opposed cylindrical holding portions 74, and is arranged at the upper end of the stopper rubber member 104. The stopper action is exerted through the inward flange portion 104A.

As shown in FIG. 3, a stopper receiving portion 93 is provided on the inner side of the base portion of the vertical wall portion 90 so as to exert a stopper action for limiting the downward relative displacement of the vehicle body side bracket 70. On the lower surface of the flange portion 21 at the lower end of the upper fixture 14, a stopper rubber portion 17 made of rubber continuous from the vibration isolating base 16 is provided, and the flange portion 21 is provided with a stopper receiving portion via the stopper rubber portion 17. The stopper action is exerted by abutting on 93.

When assembling the liquid-filled vibration isolator 10 of the present embodiment, the upper fixture 14 of the vibration isolator body 11 is press-fitted from below into the cylindrical holding portion 74 of the engine side bracket 72. Then, the stopper rubber member 104 is attached from above to the cylindrical holding portion 74 in which the upper fixture 14 is fitted. Thereafter, the cylindrical holding portion 74 side of the engine side bracket 72 is inserted from the side opening of the vehicle body side bracket 70. At that time, the fixed convex portion 100 of the lower mounting tool 14 is slid into the concave groove 94 of the fastening surface portion 86 of the vehicle body side bracket 70, and the bolt 96 is inserted from below the fastening surface portion 86 to mount the lower mounting portion. It fastens and fixes to the internal thread part 18 of the fixed convex part 100 of the tool 14.

Thus, when fastening the fixed convex part 100 with the volt | bolt 96, the fixed convex part 100 engages with the groove wall surfaces 94A and 94A on both sides in the concave groove 94 of the fastening surface part 86, respectively. Therefore, co-rotation by tightening the bolt 96 is restricted. That is, the engagement acts as a means for restricting the rotation of the fixed convex portion 100. Therefore, the bolt 96 can be accurately tightened without using a special jig.

1 to 4 assembled in this way, the vehicle body side bracket 70 is fixed to the vehicle body 1 with a bolt (not shown) at the vehicle body side fixing portion 88, and the engine The side bracket 72 is fixed to the engine 2 at the engine side fixing portion 76 using a bolt (not shown) (see FIG. 5), and is assembled to the vehicle.

In the liquid-filled vibration isolator 10 of the present embodiment, when a large amplitude vibration occurs, the annular thick part 52 of the elastic partition film 40 is pressed against the annular support part 56 of the displacement regulating means 42 and 44. It is done. At this time, since both side surfaces 52A and 52B of the thick annular thick portion 52 are formed on a flat surface without projections, the annular thick portion 52 and the annular support portion 56 abut without gaps. The liquid flow between the liquid chambers 26A and 26B around the elastic partition film 40 can be prevented, and the liquid flow effect by the orifice 36 can be effectively exhibited.

Further, when a vibration with a small amplitude occurs, as shown by an arrow L in FIG. 10, the minute gaps 60, 60 on both sides of the annular thick part 52 of the elastic partition film 40 and the axial direction X connecting the gaps extend. A liquid flow occurs between the liquid chambers 26A and 26B through the gap 62. At this time, since both side surfaces 52A and 52B of the annular thick portion 52 are flat surfaces, the liquid flow is not hindered. Therefore, coupled with the reciprocating displacement in the elastic partition film 40, excellent low motion Spring characteristics are exhibited.

18 and 19 are projections extending in the circumferential direction on both side surfaces 52A and 52B of the annular thick portion 52 of the elastic partition film 40 as a comparative example, with the liquid filled type vibration isolator 10 of the above-described embodiment (Example). The result of having measured the storage spring constant (dynamic spring constant) and the loss coefficient about what provided the strip | line is shown. 18 shows data when an amplitude of ± 1.0 mm corresponding to large amplitude vibration is loaded, and FIG. 19 shows data when an amplitude of ± 0.2 mm corresponding to small amplitude vibration is loaded. is there.

As shown in FIG. 18, at the time of large amplitude, the loss factor of the example is higher than the loss factor of the comparative example, that is, in the example, an excellent damping property equal to or better than that of the comparative example was ensured. . In the comparative example, this is thought to be due to the fact that the protrusions provided to enhance the sealing performance abut on the annular support portion in an unstable manner when the amplitude is large, thereby causing liquid leakage. In the embodiment, the side surfaces 52A and 52B of the annular thick portion 52 are formed as flat surfaces, so that the adhesion with the annular support portion 56 is enhanced at large amplitudes, and liquid leakage is effectively prevented. It was.

And as shown in FIG. 19, in the case of a fine amplitude, in an Example, the dynamic spring constant in the high frequency area (about 15-25 Hz) equivalent to an idling vibration is reducing with respect to a comparative example, and it is excellent. Low dynamic spring characteristics were obtained.

As described above, in this embodiment, the annular thick part 52 of the elastic partition film 40 is not clamped in the axial direction X, and the gaps 60 are provided on both sides, so that the displacement regulating means 42 and 44 face each other. There is a concern about the impact sound caused by the collision with the annular support portion 56. However, in the present embodiment, the cylindrical attachment provided with the partition body 34 is connected to the lower attachment 12 on the vehicle body 1 side via the vibration isolation base 16 as the upper attachment 14 attached to the engine 2 side. Thus, even if the vibration due to the collision occurs, the vibration is absorbed by the vibration isolation base 16 in the vibration transmission path to the vehicle body 1 side, so that the hitting sound due to the collision is transmitted into the vehicle interior. Can be suppressed.

In addition, in the cylindrical holding portion 74 of the engine side bracket 72 that holds the cylindrical upper fixture 14, the notch 79 is provided in a part of the circumferential direction and the mass is shaved. And the generation of abnormal noise due to approaching the resonance point of the vehicle body can be suppressed. Further, the notch 79 is provided on the distal end side of the cylindrical holding portion 74, and this portion is a portion that does not need to exert a stopper action with respect to the vehicle body side bracket 70, so that the stopper action or the like is not impaired. The mass can be reduced.

In the liquid-filled vibration isolator 10 according to the present embodiment, the plurality of protrusions 64 are provided on the film surface of the partition film main body 50 so as not to be applied to the annular support portion 56, so that the periphery of the elastic partition film 40 at the time of large amplitude is obtained. In this case, it is possible to reduce the noise caused by the collision with the displacement regulating means 42 and 44 while preventing the liquid flow between the two liquid chambers 26A and 26B.

Further, since the elastic partition film 40 has no directionality in the circumferential direction due to the arrangement of the unique protrusion 64, no matter how the elastic partition film 40 rotates, the displacement restricting means 42, 44 with respect to the restricting portion main body 54. The noise reduction effect by the protrusion 64 can be exhibited.

1 is a perspective view of a liquid filled type vibration damping device according to an embodiment of the present invention. The perspective view seen from the lower surface side of the vibration isolator. III-III sectional view taken on the line of FIG. IV-IV sectional view taken on the line of FIG. The side view of the vibration isolator. Longitudinal cross section of the vibration isolator body The top view of the partition body of the said vibration isolator. VIII-VIII sectional view taken on the line of FIG. Exploded sectional view of the partition The principal part expanded sectional view of the partition. The top view of the elastic partition membrane of the partition. The longitudinal cross-sectional view of the elastic partition membrane. The expansion perspective view which shows the lower end part of the said vibration isolator main body. The perspective view of the engine side bracket of the said vibration isolator. The perspective view seen from the lower surface side of the engine side bracket. XVI-XVI sectional view taken on the line of FIG. XVII-XVII sectional view taken on the line of FIG. The graph which shows the measurement result of the storage spring constant and loss factor at the time of the vibration of a large amplitude about the vibration isolator of an Example and a comparative example. The graph which shows the measurement result of the storage spring constant and loss factor at the time of the vibration of a minute amplitude about the vibration isolator of an Example and a comparative example.

Explanation of symbols

1 ... Body (support side)
2 ... Engine (vibration source side)
DESCRIPTION OF SYMBOLS 10 ... Liquid enclosure type vibration isolator 12 ... Lower side attachment tool, 12A ... Lower end surface 14 ... Upper side attachment tool, 14A ... Peripheral wall part 16 ... Anti-vibration base | substrate 26 ... Liquid enclosure chamber, 26A ... First liquid chamber, 26B ... No. Two liquid chambers 28 ... Diaphragm 34 ... Partition 36 ... Orifice 38 ... Orifice forming member 38D ... Inner peripheral surface 40 ... Elastic partition film 42, 44 ... Displacement restricting means 50 ... Partition membrane body 52 ... Annular thick part 52A, 52B ... side surface, 52C ... outer peripheral surface 54 ... regulator body 56 ... annular support portion 60 ... small gap 62 ... gap 64 ... projection 70 ... vehicle body side bracket (first bracket)
72 ... Engine side bracket (second bracket)
74: cylindrical holding portion, 74A: circumferential portion 76 on the opposite side of the connecting portion ... engine side fixing portion (vibration source side fixing portion)
78 ... Connecting part 79 ... Notch part 86 ... Fastening surface part 88 ... Car body side fixing part (supporting side fixing part)
90 ... vertical wall portion, 90A ... upper end 92 ... upper wall portion 94 ... concave groove, 94A ... groove wall surface 96 ... bolt 98 ... through hole 100 ... fixed convex portion, 100A ... straight side surface D1 ... spacing between annular support portions D2 ... Thickness F of the annular thick wall part ... Opposing direction G of the vertical wall part ... Direction perpendicular to the opposing direction K2 ... Radial inner side O ... Radial center X ... Axial core direction

Claims

A lower attachment attached to the support side, a cylindrical upper attachment attached to the vibration source side, a vibration isolating base made of a rubber-like elastic body connecting the lower attachment and the upper attachment, and the upper A diaphragm which is attached to a fixture and forms a liquid enclosure chamber with the vibration isolation substrate, and a partition which partitions the liquid enclosure chamber into a first liquid chamber on the vibration isolation substrate side and a second liquid chamber on the diaphragm side A body, and an orifice for communicating the first liquid chamber and the second liquid chamber,
The partition body is provided inside the peripheral wall portion of the upper fixture to form an annular orifice forming member that forms the orifice, and the first liquid chamber and the second liquid chamber are axially arranged inside the orifice forming member. A liquid-filled vibration isolator comprising: an elastic partition membrane that partitions in a direction; and a pair of displacement regulating means that regulates the amount of displacement of the elastic partition membrane from both sides of the membrane surface of the elastic partition membrane,
A first bracket for attaching the lower attachment to the support side; and a second bracket for attaching the upper attachment to the vibration source side;
The second bracket includes a cylindrical holding portion into which the upper fixture is press-fitted in the axial direction, a vibration source side fixing portion for fixing to the vibration source side, and the cylindrical holding portion and the vibration source side fixing. And a notch that is concave in the axial direction in the circumferential portion on the opposite side of the coupling portion of the cylindrical holding portion, and the axial direction of the circumferential portion. The width at
The elastic partition membrane is composed of a partition membrane main body, and an annular thick portion provided around the partition membrane main body in a thicker shape than the partition membrane main body,
The pair of displacement restricting means are spaced apart and opposed to the partition membrane main body in the axial direction so as to restrict displacement in the axial direction of the partition membrane main body, and the annular thick portion is the axial core. It consists of an annular support part that supports so as to be sandwiched from both sides of the direction,
Both side surfaces in the axial direction of the annular thick portion are formed as flat surfaces perpendicular to the axial direction, and the flat surfaces are provided so as to face the entire annular support portion in the entire radial direction. The distance between the pair of annular support portions opposed to each other in the core direction is set larger than the thickness of the annular thick portion, so that one side surface and the one side surface in the axial core direction of the annular thick portion A minute gap is provided between the annular support portion and the other annular support portion facing the other side surface in the axial direction of the annular thick portion. And a gap extending in the axial direction connecting between the minute gaps on both sides of the annular thick portion is between the outer peripheral surface of the annular thick portion and the inner peripheral surface of the orifice forming member. Thus, with respect to the fine amplitude vibration, While the liquid flow is generated between the first liquid chamber and the second liquid chamber through a small gap, the annular thick portion abuts against the annular support portion with no gap against large amplitude vibrations. The liquid flow between the first liquid chamber and the second liquid chamber around the elastic partition membrane was prevented.
A liquid-filled vibration isolator characterized by that.
The first bracket includes a fastening surface portion to which a lower end surface of the lower fixture is fixed, a pair of support side fixing portions for fixing to the support side located on both sides of the fastening surface portion, A pair of vertical wall portions provided on both sides of the cylindrical holding portion with the cylindrical holding portion interposed therebetween, and upper ends of the pair of vertical wall portions above the cylindrical holding portion. And an upper wall portion for connecting the
The fastening surface portion is provided with a concave groove extending in a direction perpendicular to the opposing direction of the pair of vertical wall portions, and a through hole penetrating in the axial direction is provided in the concave groove,
A fixed convex portion that slides and fits into the concave groove is provided on the lower end surface of the lower fixture, and the fixed convex portion engages with one groove wall surface of the concave groove. And having the other side surface in a straight shape that engages with the other groove wall surface of the concave groove, and the engagement between the one side surface and the other side surface and the one groove wall surface and the other groove wall surface. The rotation of the fixed convex portion is configured to be restricted, and the fixed convex portion is fastened and fixed to the fastening surface portion by a bolt inserted from below into the through hole.
The liquid-filled type vibration damping device according to claim 1.
3. The liquid according to claim 1, wherein a plurality of protrusions are provided on a membrane surface of the partition membrane main body in a region radially inward from the annular support portion of the displacement regulating means. Enclosed vibration isolator.
The elastic partition membrane has a circular shape when viewed in the axial direction, and the protrusions are arranged in a plurality of rings concentrically surrounding the radial center of the elastic partition membrane and arranged in parallel at equal intervals in the circumferential direction. 3. Liquid-filled vibration isolator according to 3.