JP4358417B2 - Liquid seal vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid seal vibration isolator provided with an elastic film that can be elastically deformed by changing the liquid pressure in a main liquid chamber, and more particularly to a non-circular member made of an elastic film.
[0002]
[Prior art]
The elastic membrane has a circular shape, absorbs the hydraulic pressure change of the main liquid chamber by elastic deformation of the elastic membrane, and is integrally formed with a stopper projection forming an annular wall on the surface of the elastic membrane on the side of the sub liquid chamber. It is known that the spring constant is non-linearly changed by coming into contact with the partition member side or the like.
[0003]
[Problems to be solved by the invention]
By the way, there is a case where such a circular elastic film cannot be arranged depending on layout conditions, and the elastic film needs to be a non-circular member that shakes the long side and the short side such as an oval. However, when the conventional circular elastic membrane is simply a non-circular member such as an oval, the main liquid chamber is formed by being sandwiched by the partition member long along the long side portion and the stopper protrusions being annularly continuous. Even if the hydraulic pressure changes, it is difficult to bend correspondingly, and as a result, it is difficult to absorb the increase in internal pressure. Therefore, the present invention can absorb the increase in internal pressure by easily bending following the change in the internal pressure even if an elastic film of a non-circular member is used, and if the predetermined elastic deformation amount is exceeded, the spring constant is nonlinear as in the conventional case. The purpose is to make changes.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, a liquid seal vibration isolator according to the present invention includes a first attachment member attached to either the vibration generating side or the vibration receiving side, a second attachment member attached to the other side, and these A main liquid chamber having the elastic main body member as a part of a wall, a sub liquid chamber partitioned by the main liquid chamber and the partition member and covered with a flexible membrane member, In addition, a damping orifice passage that continues through these two liquid chambers, and an elastic membrane that is provided in the partition member and elastically deforms due to an internal pressure variation of the main liquid chamber,
The elastic film is formed as a non-circular member having a long side part and a short side part, and a bending groove substantially parallel to the long side part is formed in the central part of the elastic film.
[0005]
At this time, a stopper protrusion substantially parallel to the bending groove can be integrally formed on the surface of the elastic film opposite to the bending groove, and the stopper protrusion can be formed only on the long side portion. Further, the periphery of the elastic film can be integrally formed to form a continuous annular peripheral wall. The peripheral wall can be sandwiched by the partition member, and a clearance that allows deformation of the peripheral wall can be formed in the sandwiching portion of the partition member.
[0006]
Further, the partition member is provided with first to third orifice passages, the first orifice passage is an attenuation orifice passage that always communicates the main liquid chamber and the sub liquid chamber, the second orifice passage is openable and closable, The orifice passage of this is partly covered by an elastically deformable elastic film to cut off the communication between the main liquid chamber and the sub liquid chamber,
This elastic film can also be formed as the non-circular member.
[0007]
【The invention's effect】
When the internal pressure of the main liquid chamber rises, the elastic membrane is bent and deformed in a shearing manner with the bending groove at the central portion substantially parallel to the long side portion as the bending starting point. For this reason, even if the elastic film is a non-circular member having a long side portion and a short side portion, it can bend easily following the increase in the internal pressure of the main liquid chamber, and the internal pressure of the main liquid chamber can be reduced by reducing the dynamic spring. Can absorb the rise.
[0008]
In addition, if the stopper protrusion protrudes from the surface opposite to the bending groove of the non-circular member, when a large vibration is input to the main liquid chamber, the stopper protrusion contacts the partition member, thereby causing the spring constant of the elastic film to be nonlinear. Changes large and can absorb large input. Moreover, the elastic film can be bent more easily by providing the stopper protrusions only on the long side portion side and the discontinuous shape not provided on the short side portion side.
[0009]
In addition, the elastic membrane can be more easily deformed by forming a clearance with the peripheral wall at the holding portion of the partition member with respect to the peripheral wall.
[0010]
Further, the partition member is provided with first to third orifice passages, the first orifice passage is an attenuation orifice passage that always communicates the main liquid chamber and the sub liquid chamber, the second orifice passage is openable and closable, In the case where the orifice passage is configured so as to cut off the communication between the main liquid chamber and the sub liquid chamber by covering a part with an elastically deformable elastic film, the circular film is formed by forming the elastic film as the non-circular member. Thus, it is possible to lay out even in a limited space of the partition member which cannot be provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment configured as an engine mount will be described with reference to the drawings. FIG. 1 is a full sectional view of the engine mount, and FIG. 2 is an enlarged view of a portion A in FIG. First, in FIG. 1, reference numeral 1 denotes a first attachment member attached to the engine side by a bolt portion 2, 3 denotes a second attachment member attached to the vehicle body side by a bolt 4, and 5 denotes an elastic main body member. It is made of an elastic member, and has a substantially conical dome portion 6 and a cylindrical portion 7 continuous therewith.
[0012]
The cylindrical portion 7 is bonded and integrated to the inner peripheral side of the substantially cylindrical rigid wall 8, and the outer peripheral side of the rigid wall 8 is integrated with the cylindrical portion 3 a formed as a part of the second mounting member 3. ing. A circular hole 9 is formed in a part of the cylindrical part 3a and the rigid wall 8, and a part of the cylindrical part 7 covering the cylindrical hole 7 forms a movable film 10 and is elastically deformable.
[0013]
The movable membrane 10 is covered with a holder 11 having a substantially funnel-shaped cross section from the outside of the cylindrical portion 3a, and a pipe portion 12 protruding from the outside from the center is connected to a switching valve 14a. Opening and connection to a negative pressure source, such as an engine intake negative pressure, are switched.
[0014]
The inside of the holder 11 forms a control chamber 13, and changes between an open air state and a negative pressure state by switching the switching valve. A movable film stopper 15 made of an elastic member such as rubber is provided between the holder 11 and the movable film 10 so as to restrict elastic deformation of the movable film 10 by a predetermined amount.
[0015]
The opening of the cylindrical portion 7 is covered with a partition member 16, and a main liquid chamber 20 having the elastic main body member 5 as a part of a wall is formed between the partition member 16 and the elastic main body member 5. A sub liquid chamber 22 covered with a diaphragm 21 is formed on the opposite side of the partition member 16 from the main liquid chamber 20, and an incompressible liquid is sealed in the main liquid chamber 20 and the sub liquid chamber 22. The partition member 16 has a structure in which three members of an upper partition 17, an intermediate partition 18, and a lower partition 19 are overlapped, and each member is formed of an appropriate rigid material such as a synthetic resin.
[0016]
A spiral damping orifice passage 23 is formed between the upper partition 17 and the intermediate partition 18 and between the intermediate partition 18 and the lower partition 19, and one end thereof is a common passage formed between the upper partition 17 and the intermediate partition 18. The other end communicates with the auxiliary liquid chamber 22 through an opening (not shown) formed in a part of the lower partition 19.
[0017]
The common passage 24 sequentially communicates with an idle orifice passage 25, which is a second orifice passage formed in the upper partition 17, and an orifice hole 26 as a third orifice passage. The orifice hole 26 opens to the main liquid chamber. Accordingly, the main liquid chamber 20 and the sub liquid chamber 22 are always communicated to generate a damping force and absorb a vibration with a relatively low frequency and a large amplitude such as suspension vibration.
[0018]
The bottom of the orifice hole 26 is covered with an elastic film 27 made of an elastic member such as rubber and is disconnected from the width liquid chamber 22 side. Due to the membrane vibration of the elastic membrane 27, the liquid in the orifice hole 26 generates a liquid column resonance in a relatively high frequency range such as when starting.
[0019]
An opening of an idle orifice passage 25 (not shown) faces the orifice hole 26, and the idle orifice passage 25 communicates with the damping orifice passage 23 via the common passage 24 as described above. Although these opening areas are not shown, the resonance frequency of each liquid column resonance is tuned to decrease in this order by setting the orifice hole 26> the idle orifice passage 25> the damping orifice passage 23 in this order.
[0020]
The idle orifice passage 25 has its outlet 28 on the side of the secondary liquid chamber 22 opened and closed by a thick wall portion 21a formed at the center of the diaphragm 21, and when opened, the main liquid chamber 20 and the secondary liquid chamber 22 communicate with each other. The vibration at the time is absorbed by the liquid column resonance on the higher frequency side than the damping orifice passage 23.
[0021]
The opening / closing operation of the thick portion 21a is performed by a separate opening / closing member 30. The opening / closing member 30 is biased by the return spring 31 toward the side where the thick portion 21a is brought into close contact with the periphery of the outlet 28, and forms a working chamber 32 which is a closed space between the bottom member 33 and the bottom member It communicates with a pipe portion 34 formed at the center of 33. The pipe part 34 is connected to the switching valve 14b, and switches between the atmospheric release state and the negative pressure state. When switching between the working chamber 32 and the control chamber 13 in synchronization, the switching valves 14a and 14b can be made common.
[0022]
When the inside of the working chamber 32 is brought into a negative pressure state, the opening / closing member 30 is pulled downward against the return spring 31. As a result, the thick portion 21a is separated from the periphery of the outlet 28, and the outlet 28 is opened. The orifice passage 25 is communicated with the main liquid chamber 20 and the sub liquid chamber 22.
[0023]
The partition member 16 is integrated on the inner peripheral side of the caulking flange 8a and the lower cylindrical member 35 by caulking the caulking flange 8a formed at the lower portion of the rigid wall 8 in the drawing and the upper portion of the lower cylindrical member 35. It is clamped and fixed between the fixed flange members 36. Further, the outer peripheral portions of the opening / closing member 30 and the bottom member 33 are overlapped and fixed by crimping the upper and lower ends of the ring member 37 integrated with the lower inner periphery of the lower cylindrical member 35 in the figure. Reference numeral 38 denotes a vent hole formed in the lower cylindrical member 35 so as to partially overlap the ring member 37.
[0024]
The second mounting member 3, the rigid wall 8, the lower cylindrical member 35, the fixed flange member 36, and the ring member 37 are all made of an appropriate material having rigidity such as metal. Reference numeral 39 in the figure denotes a medium-high frequency device having a substantially dish shape, which causes liquid column resonance with the dome portion 6 in the medium-high frequency range.
[0025]
As shown in FIG. 2, the elastic membrane 27 has a main body portion 50 closed across the middle portion of the orifice hole 26, and a bending groove 51 is formed on the main liquid chamber 20 side in the central portion.
[0026]
A pair of stopper projections 52 and 52 are formed on the surface on the side of the secondary liquid chamber 22 opposite to the bending groove 51 with a central portion interposed therebetween, and contact slopes 53 and 53 are formed on the outer sides of the tips. Yes. A curved recess 54 is formed between the stopper protrusions 52 and 52. Further, the periphery of the main body portion 50 forms an annular thin portion 55, and a vertical wall-shaped peripheral wall 56 that surrounds the main body portion 50 in an annular shape is formed on the outer edge of the thin portion 55.
[0027]
3 shows a plan view of the elastic membrane 27 as viewed from the main liquid chamber 20 side, and FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. The same. 5 is a cross-sectional view taken along line 5-5 of FIG. 3 and shows a long-side cross section, and FIG. 6 is a bottom view of the elastic film 27.
[0028]
As shown in these drawings, the elastic film 27 has an oval shape having a long side portion 57 and a short side portion 58, and the bending groove 51 is formed in the range of the long side portion 57 in parallel with the long side portion 57. . In addition, in this application, the short side part 58 is a round part which connects between the edge parts of the parallel long side parts 57 and 57, and the straight line which connects between the edge parts of the long side parts 57 and 57 parallel to a short side side. And a portion surrounded by the short side portion 58.
[0029]
Similarly, the stopper protrusions 52 are paired with the bending groove 51 interposed therebetween, and are formed in parallel with the bending groove 51 and the long side portion 57. Both ends in the length direction of each stopper projection 52 are free ends, and no stopper projection is formed on the short side portion 58 side to connect the opposing free ends.
[0030]
The thin wall portion 55 and the peripheral wall 56 are formed on the front and back surfaces of the elastic film 27 continuously in an annular shape in the circumferential direction, and the peripheral wall 56 protrudes long and front and back. The protruding length in this embodiment is longer than the protruding amount of the stopper protrusion 52.
[0031]
As apparent from FIG. 2, the peripheral wall 56 is fitted into an annular groove 61 formed in the bifurcated portion 60 of the upper partition 17 on the upper side in the figure. Of the bifurcated portion 60, the inner peripheral portion 62 forms a step portion that narrows the passage cross-sectional area at the intermediate portion of the orifice hole 26, the surface facing the annular groove 61 forms a slope 63, and the tip of the slope 63 has a thin portion 55. Is close to. The slope 63 bends the upright peripheral wall 56 like an imaginary line outward, and forms a clearance 64 between the front end side and the peripheral wall 56, and is elastically deformed so that the peripheral wall 56 bends inward. Is allowed.
[0032]
On the other hand, the lower side of the peripheral wall 56 in FIG. 2 is fitted into an annular groove 66 formed in the bifurcated portion 65 of the lower partition 19, and the inner circumferential portion 67 of the bifurcated portion 65 has a predetermined clearance between the stopper projection 52. The portion adjacent to the thin-walled portion 55 on the distal end side forms a narrow portion, and the intermediate portion forms a stepped portion 68 on the slope facing the contact slope 53, so that the lower portion becomes a wide portion. Yes.
[0033]
As a result, when the elastic film 27 is elastically deformed, the left and right stopper protrusions 52 and 52 are opened outward, and when the elastic film 27 is deformed as indicated by an imaginary line in FIG. The distal end portion of the stopper projection 52 is elastically deformed, and when further elastically deformed, the entire stopper projection 52 is pressed against the narrow portion on the distal end side of the inner peripheral portion 67 to be deformed.
[0034]
Next, the operation of this embodiment will be described. When there is a relatively small vibration input to the main liquid chamber 20, the internal pressure rises in response to this vibration input, and the main body 50 of the elastic membrane 27 is pushed downward from above in FIG. Then, since the bending groove 51 is formed in the central portion in parallel with the long side portion 57, the main body portion 50 is bent in a shearing manner with the bending groove 51 as a starting point in the short side section of FIGS.
[0035]
Therefore, although the long side portion 57 is linearly fixed to the partition member 16 side in a long range, it can be easily elastically deformed in response to the increase in the internal pressure of the main liquid chamber 20 to absorb the increase in internal pressure, Achieves low dynamic springs.
[0036]
In addition, it is easier to bend in the direction of the short side portion 58 by making the both ends in the length direction of the stopper projections 52, 52 free ends and making the discontinuous shape not forming the stopper projection 52 on the short side portion side. .
[0037]
In addition, by tilting the upper portion of the peripheral wall 56 so as to open outward on the slope 63 of the inner peripheral portion 62, the initial spring constant of the elastic film 27 is increased and the clearance 64 is provided, whereby the main body portion 50 side is elastically deformed. When this is done, the peripheral wall 56 can be elastically deformed more easily by elastic deformation.
[0038]
After that, if there is a greater vibration input, the stopper projections 52, 52 open in directions in which the tip ends are separated from each other, so that the abutting slope 53 first contacts the step 68 of the inner peripheral portion 67 so that the tip end side of the stopper projection 52 is moved. By elastically deforming, the spring constant of the elastic film 27 is increased.
[0039]
If the elastic film 27 is further elastically deformed, the stopper protrusions 52 and 52 are entirely pressed against the narrow width portion of the inner peripheral portion 67 and are elastically deformed, so that the spring constant is further increased.
[0040]
Therefore, for a large vibration input, the spring constant is changed nonlinearly corresponding to the magnitude of the vibration input, and by increasing the spring constant, the flow rate of the liquid flowing into the damping orifice passage 23 is increased, thereby reducing the liquid column resonance to the damping orifice. By generating in the passage 23, a large damping force is generated and absorbed.
[0041]
FIG. 7 is a graph showing the relationship between the dynamic spring constant and frequency at the time of small amplitude, FIG. 8 is a graph showing the damping characteristic at the time of large amplitude, the solid line is the same ellipse shape as the present example, the broken line is the same ellipse shape as a comparative example, A configuration in which the bending groove 51 is not provided and the stopper protrusion is formed in an annular shape is shown. FIG. 7 shows that this embodiment can realize a remarkable low dynamic spring, and FIG. 8 shows that high damping comparable to the conventional one can be realized.
[0042]
As can be seen from these graphs, the low dynamic springs can be used for small vibration inputs, and high vibrations can be achieved for large vibration inputs.・ High attenuation characteristics can be obtained.
[0043]
Moreover, even if the damping orifice passage 23, the idle orifice passage 25 and the orifice hole 26 and the three orifice passages are formed side by side in the partition member 16, the elastic film 27 provided in the orifice hole 26 is formed into an oval noncircular member. The elastic film 27 can be disposed even under layout conditions that are difficult with a circular elastic film.
[Brief description of the drawings]
1 is an overall cross-sectional view of an engine mount according to an embodiment. FIG. 2 is an enlarged view of part A in FIG. 1. FIG. 3 is a plan view showing an elastic membrane of the embodiment from the main liquid chamber side. FIG. 5 is a sectional view taken along line 4-5 of FIG. 3. FIG. 6 is a sectional view taken along line 5-5 of FIG. 3. FIG. 6 is a bottom view of the elastic membrane. Attenuation characteristic chart [Explanation of symbols]
1: 1st mounting member, 2: 2nd mounting member, 5: elastic body member, 7: cylindrical part, 9: circular hole, 10: movable membrane, 13: control chamber, 14: switching valve, 15: movable membrane Stopper 16 :, partition member, 20: main liquid chamber, 21: diaphragm, 22: auxiliary liquid chamber, 23: damping orifice passage, 24: common passage, 25: idle orifice passage, 26: orifice hole, 27: elastic membrane, 28: outlet, 30: opening and closing member, 40: contact surface, 41: protrusion, 42: discontinuous part, 43: stopper hole, 44: gap, 50: main part of elastic film, 51: bending groove, 52: stopper protrusion , Peripheral walls 56, 57: long side portion, 58: short side portion, 64: clearance

Claims (3)

A first attachment member attached to either the vibration generating side or the vibration receiving side;
A second attachment member attached to the other side;
An elastic body member interposed between them,
A main liquid chamber whose elastic body member is a part of the wall;
Partitioned by the main liquid chamber and the partition member,
A secondary liquid chamber covered with a flexible membrane member;
Attenuating orifice passage that passes through both liquid chambers,
In a liquid seal vibration isolator provided with an elastic film provided on the partition member and elastically deforming due to fluctuations in internal pressure of the main liquid chamber,
Forming the elastic membrane as a non-circular member having a long side and a short side ;
While forming a bending groove substantially parallel to the long side part in the central part of the elastic membrane,
A stopper projection substantially parallel to the bending groove is integrally formed on the surface opposite to the bending groove of the elastic film,
A liquid seal vibration isolator characterized in that the stopper protrusion is formed only on the long side portion .  The periphery of the elastic membrane is integrally formed to form a continuous annular peripheral wall, the peripheral wall is sandwiched by a partition member, and a clearance that allows deformation of the peripheral wall is formed in a sandwiching portion of the partition member. Item 2. The liquid seal vibration isolator according to item 1.  The partition member is provided with first to third orifice passages, the first orifice passage is an attenuation orifice passage that always communicates the main liquid chamber and the sub liquid chamber, the second orifice passage is openable and closable, The orifice passage is partially covered by an elastically deformable elastic film to cut off the communication between the main liquid chamber and the sub liquid chamber, and the elastic film is formed as the non-circular member. Liquid seal vibration isolator.

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