JP4374080B2 - Liquid seal vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid seal vibration isolator suitable for use in an automobile engine mount or the like.
[0002]
[Prior art]
A liquid seal vibration isolator provided with an elastic film part that is elastically deformed so as to absorb a change in the internal pressure of the main liquid chamber is known, for example, Japanese Patent No. 2799953. FIG. 8 is an enlarged cross-sectional view of a part of the partition member in such a conventional example. The partition member includes an elastic partition member a, a holding plate b covering one surface side thereof, and a peripheral portion of the elastic partition member a. A peripheral fixing portion d for fitting and supporting c is provided, the central portion of the elastic partition member a forms an elastic film portion e, and a stopper leg portion f having a substantially L-shaped cross section is formed on the back surface thereof so as to be fixed in the periphery. The spring constant of the elastic film part a is nonlinearly changed by pressing against the inner peripheral wall g of the part. In addition, an opening h that opens the elastic film portion e is provided in the center portion of the holding plate b.
[0003]
[Problems to be solved by the invention]
By the way, according to the above-described conventional example, as shown by the curve A in FIG. However, since the peak P1 due to the membrane resonance of the elastic membrane part e occurs, it is desirable to make this as low as possible. However, in order to realize this, it is required to be realized with a simpler structure. The present invention fulfills such a demand.
[0004]
[Means for Solving the Problems]
In order to solve the above-described problems, the invention relating to the liquid seal vibration isolator of the present application includes a first attachment member attached to the vibration source side, a second attachment member attached to the vehicle body side, and an outline provided therebetween. A liquid chamber having a conical elastic main body portion and having the elastic main body portion as a part of a wall is formed, and the liquid chamber is partitioned into a main liquid chamber and a sub liquid chamber by a partition member, and the main liquid The auxiliary liquid chamber is connected with a damping orifice passage that absorbs low-frequency vibrations, and an elastic membrane portion that is elastically deformed to absorb the change in the internal pressure of the main liquid chamber is provided in at least a part of the partition member. In the liquid seal vibration isolator in which a stopper leg portion having a substantially L-shaped cross section is integrally formed from the chamber side, and the protruding end is pressed against the peripheral fixing portion of the partition member, the partition member includes an elastic membrane portion. Elastic partition member formed in part and restraint covered on this And a peripheral fixing part that supports a peripheral part that is an outer peripheral part of the elastic partition member, and an opening part that opens an upper part of the elastic film part is provided at a central part of the restraining plate, and an outer peripheral side of the opening part A tightening protrusion is integrally provided on the base plate, and the elastic partition member is sandwiched between the tightening protrusion and the peripheral fixing portion.
[0005]
In the above invention, the fastening point by the peripheral fixing portion is connected to the peripheral portion of the elastic partition member and the elastic film on the inner peripheral side to make the connection portion thinner than the peripheral portion, and the fastening point by the fastening protrusion is By positioning on the outer peripheral side of the fastening point by the peripheral fixing part, the fastening points by the fastening protrusion and the peripheral fixing part are arranged separately on the inner and outer peripheral sides ,
Furthermore, as possible out also Rukoto to position the edge of the restraining opening provided in the central portion of the plate above the upper end portion supporting the connecting portion of the peripheral fixed part.
[0006]
【The invention's effect】
Suppressed tighten to form a protrusion on the outer peripheral side of the aperture portion of the plate, for clamping the resilient partition member by the the fastening projection and the surrounding stationary part, it is possible to provide an initial deflection to the elastic membrane portion can lower the film stiffness. As a result, it is possible to adjust the membrane resonance of the elastic membrane portion and lower the peak frequency. In addition, it can be realized with a simple structure by simply adding a tightening protrusion to the holding plate.
[0007]
In addition, if the fastening points by the fastening protrusions are positioned closer to the outer circumference side than the fastening points for the connecting parts by the peripheral fixing parts, the fastening points of the fastening protrusions and the peripheral fixing parts can be shifted to the inner and outer peripheral sides to be elastic. A predetermined initial deflection is given to the film part, and thereby the film rigidity of the elastic film part can be adjusted more precisely.
[0008]
In addition, if the position of the opening is changed and expanded, for example, to a position closer to the tightening protrusion than the tightening point of the peripheral fixing portion, the internal pressure absorbing force of the elastic film portion increases, so that the dynamic spring can be reduced accordingly. Therefore, if the opening is arbitrarily adjusted within the range up to the tightening projection, the degree of low dynamic spring can be freely adjusted.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment configured as an automobile engine mount will be described below with reference to the drawings. 1 is an enlarged cross-sectional view showing a part of the elastic partition member, FIG. 2 is an overall cross-sectional view of the engine mount, FIGS. 3 to 5 are cross-sectional views shown for each component in FIG. FIG. 4 shows an elastic partition member, and FIG. 5 shows a peripheral fixing part. FIG. 6 is a view similar to FIG. 1 showing a modification, and FIG. 7 is a graph of a dynamic spring constant showing the effect.
[0010]
In FIG. 2, the engine mount includes a first attachment member 1 attached to the engine side, a second attachment member 2 attached to the vehicle body side, and an elastic main body 3 integrally provided by connecting them. Prepare. The elastic main body 3 is a substantially conical member made of an appropriate elastic material made of known rubber or the like, and the top of the conical portion 4 is integrated with the first mounting member 1 passing therethrough.
[0011]
The inner surface of the conical portion 4 forms an inner wall surface of a liquid chamber described later. Further, the periphery of the bottom of the conical portion 4 forms a flange 6, and the lower portion extends further downward from the flange 6 to form the lining portion 7. The flange 6 is integrated into the flange 9 shape of the cylindrical side wall portion 8 constituting a part of the second mounting member 2, and the lining portion 7 covers the inner surface of the side wall portion 8.
[0012]
The inside of the elastic main body 3 forms a space opened downward, and this open part is covered with a diaphragm 10, thereby forming a liquid chamber inside. The liquid chamber is partitioned by a partition member 11 into a main liquid chamber 12 on the elastic body 3 side and a sub liquid chamber 13 on the diaphragm 10 side, and both liquid chambers are formed by a damping orifice passage 14 formed in the outer peripheral portion of the partition member 11. Communicated.
[0013]
The partition member 11 includes a cup-shaped member 16 having a groove 15 opened upward at the outer peripheral portion, an elastic partition portion 18 made of an appropriate elastic material such as rubber with a peripheral portion 17 fitted into the groove 15, It is comprised by three members with the holding | suppressing plate 20 covered over.
[0014]
The three constituent members of the partition member 11 are stacked and integrated one above the other, and the periphery is fixed to the inside of the connecting portion together with the diaphragm 10 when the lower portion 8a of the side wall portion 8 and the base cover 19 are connected by caulking. The elastic partition member 18 is fastened from above and below by the restraining plate 20 and the cup-shaped member 16 by the caulking force.
[0015]
As apparent from FIGS. 1 and 4, the elastic partition portion 18 is formed with a ring-shaped groove 22 for fitting the inner wall 21 of the cup-shaped member 16 on the back side (lower side in the figure). The inner side forms an elastic film portion 23 that is thinned from the back side. The elastic film part 23 is a part that enables sufficient elastic deformation to absorb the change in internal pressure of the main liquid chamber 12 used for elastic deformation of the elastic main body part 3.
[0016]
Moreover, the peripheral part 17 which forms the damping orifice channel | path 14, and the connection part 24 which connects the elastic film part 23 are integrated. On the side of the auxiliary liquid chamber, which is the back surface of the elastic membrane portion 23, a stopper leg portion 25 having a substantially L-shaped cross section is integrally formed in an annular shape along the ring-shaped groove 22, and its protruding end is formed with an acute angle. 26.
[0017]
As shown in FIGS. 1 and 3, the holding plate 20 has an opening 27 at the center, and an annular clamping protrusion 28 is integrally formed on a surface that overlaps the elastic partition member 18 on the outer peripheral side surrounding the opening 27. Protrusions are formed. The opening 27 is formed at a position above the elastic film portion 23 so that the upper surface of the opening 27 can be directly exposed to the main liquid chamber 12.
[0018]
As shown in FIG.1 and FIG.4, as for the cup-shaped member 16 which makes the periphery fixing | fixed part in this invention, the upper end part 30 of the inner wall 21 makes a round shape. The height of the upper end 30 is lower than the outer wall 31 by the thickness of the connecting portion 24.
[0019]
As apparent from FIG. 1, the inner wall 21 is fitted into the ring groove 22, and the upper end portion 30 supports the connecting portion 24 from below. Further, the elastic partition member 18 is fixed to the cup plate 16 and the cup plate 16 by abutting the holding plate 20 against the upper surface of the elastic partition member 18 to integrate the three members and then fixing the periphery with the second mounting member 2. It can be tightened from above and below.
[0020]
At this time, the inner peripheral surface of the upper surface of the peripheral portion 17 is tightened from above by the tightening protrusion 28, and this point is set as a protrusion tightening point 32. Further, the connecting portion 24 which is on the inner peripheral side than this is tightened from the lower side by the upper end portion 30, and an extended portion of the inner wall 21 among the tightened portions is defined as an upper end side tightening point 33.
[0021]
The difference between the upper end side tightening point 33 and the protrusion tightening point 32 is a support span having a dimension S. By providing this support span, the outer peripheral side is pushed downward by the tightening protrusion 28 and the inner peripheral side is the upper end portion. A predetermined initial deflection is given to the elastic film portion 23 by pushing upward by the side fastening point 33. It should be noted that by setting the protrusion heights of the upper end portion 30 and the tightening protrusion 28 and the dimension S of the support span, adjustment such as increasing the membrane rigidity of the elastic membrane portion 23 can be made, and the degree thereof can be arbitrarily set.
[0022]
The protruding end 26 is pressed against the side surface of the inner wall 21 and slides, and the amount of pressing increases as the amount of change in the elastic film portion 23 increases. Therefore, due to the presence of the stopper leg portion 25 , the spring constant of the elastic film portion 23 can be changed nonlinearly with respect to the displacement amount.
[0023]
The diameter of the opening 27 can be arbitrarily adjusted. As shown in FIG. 1, the diameter D1 is smaller than the upper end side tightening point 33 and the upper end side tightening point 33 as shown in FIG. Any of the large diameters D2 that are on the outer peripheral side than the side is possible, and if the diameter is increased, the area facing the main liquid chamber 12 increases accordingly, so that the internal pressure can be absorbed more and a low dynamic spring can be realized. .
[0024]
Reference numeral 34 in FIG. 2 denotes a medium / high frequency device, which is attached to one end portion of the first attachment member 1 that protrudes into the main liquid chamber 12 in a substantially disk shape, and the inner wall surface 5 of the elastic main body portion 3. The liquid intervening between them is caused to resonate in a predetermined medium-high frequency range.
[0025]
Next, the operation of this embodiment will be described. First, as shown in FIG. 1, when the upper end side tightening point 33 and the protrusion tightening point 32 are shifted from each other toward the inner and outer peripheral sides, the film rigidity of the elastic film portion 23 is lowered by the tightening, and a predetermined initial In order to give deflection, the dynamic spring curve is shown by curve B in FIG.
[0026]
FIG. 7 is a graph with the frequency on the horizontal axis and the dynamic spring constant on the vertical axis. In the case of curve B, the overall dynamic spring constant is slightly reduced as the membrane rigidity is lowered, and the peak P2 of membrane resonance is the same. It can be made lower than P1, and the overall dynamic spring constant can be leveled at a sufficiently low dynamic spring level, which is more preferable in practice. In addition, since it is only necessary to provide the tightening protrusion 28, it is not necessary to provide a special new structure, and such characteristics can be realized with a simple structure.
[0027]
Further, when the inner diameter D2 of the opening 27 is increased as shown in FIG. 6, the whole is further lowered by a dynamic spring due to an increase in the internal pressure absorption force in the elastic film portion 23, so that the dynamic spring curve C of FIG. Rather, the entire dynamic spring can be made lower. That is, a region indicated by E in FIG. 7 is a liquid column resonance portion by the medium-frequency device 34, and a sufficiently low dynamic spring is provided on a lower frequency side than this region.
[0028]
The present invention is not limited to the above-described embodiments, and various modifications and applications are possible. The support span S between the upper end side tightening point 33 and the protrusion tightening point 32 can be arbitrarily set. Further, the change in the inner diameter of the opening 27 can be combined with the change in the support span S, thereby enabling extremely fine tuning.
[Brief description of the drawings]
FIG. 1 is an enlarged cross-sectional view of a main part according to an embodiment. FIG. 2 is an overall cross-sectional view of an engine mount of the embodiment. FIG. 3 is a view showing one component member in FIG. [Fig. 6] Fig. 6 is a diagram showing a modification. Fig. 7 is a graph showing an effect. [Fig. 8] Fig. 8 is a diagram showing a conventional example.
1: 1st attachment member, 2: 2nd attachment member, 3: elastic body part, 11: partition member, 12: main liquid chamber, 13: sub liquid chamber, 16: cup-shaped member, 18: elastic partition part , 20: restraining plate, 21: inner wall, 23: elastic film part, 24: connecting part, 25: stopper leg part, 27: opening part, 28: fastening protrusion, 30: upper end part, 32: protrusion side fastening point, 33 : Upper end side tightening point

Claims (2)

A first attachment member attached to the vibration source side; a second attachment member attached to the vehicle body side; and a substantially conical elastic main body provided between the first attachment member and the second main body. The liquid chamber is divided into a main liquid chamber and a sub liquid chamber by a partition member, and the main liquid chamber and the sub liquid chamber communicate with each other through a damping orifice passage that absorbs low-frequency vibrations. In addition, an elastic membrane part that is elastically deformed to absorb changes in the internal pressure of the main liquid chamber is provided on at least a part of the partition member, and a stopper leg part having a substantially L-shaped cross section is integrally formed from the sub liquid chamber side. And in the liquid seal vibration isolator that presses the protruding end against the peripheral fixing part of the partition member,
The partition member includes an elastic partition member having an elastic film portion formed in part, a restraining plate placed on the elastic partition member, and a peripheral fixing portion that supports a peripheral portion serving as an outer peripheral portion of the elastic partition member,
An opening for opening the upper portion of the elastic film portion is provided at the center of the holding plate, and a fastening protrusion is integrally provided on the outer peripheral side of the opening. The elastic partition member is formed by the fastening protrusion and the peripheral fixing portion. Pinch and tighten,
The fastening point by the peripheral fixing part is connected to the peripheral part of the elastic partition member and the elastic film on the inner peripheral side to make the connecting part thinner than the peripheral part,
By positioning the tightening points by the tightening protrusions on the outer peripheral side with respect to the tightening points by the peripheral fixing portion, the respective tightening points are separately arranged on the inner and outer peripheral sides ,
Furthermore, the liquid seal vibration isolator characterized in that the edge of the opening provided in the central portion of the holding plate is positioned above the upper end of the peripheral fixing portion that supports the connecting portion .   2. The peripheral fixing portion is provided with a damping orifice passage, and a portion thicker than the connection portion between the damping orifice passage and the peripheral fixing portion is fastened by the fastening protrusion. Liquid seal vibration isolator.

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