JP4400809B2 - Liquid seal vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid seal vibration isolator for use in an engine mount or the like, in which a cylindrical bush and a conical mount are integrated.
[0002]
[Prior art]
A first attachment member attached to the vibration generating side, a second attachment member attached to the vibration receiving side, and a substantially conical elastic body member connecting the first attachment member and the second attachment member A liquid chamber having the elastic body portion as a part of the elastic wall portion inside the elastic body portion, the liquid chamber being partitioned into a main liquid chamber and a sub liquid chamber by a partition member, and both liquid chambers Conical mounts are known which are connected by a first orifice passage. A cylindrical bush is also known in which cylindrical inner and outer cylinders are connected by an elastic member, a plurality of liquid chambers partitioned by an elastic member in the circumferential direction are provided, and the liquid chambers are connected by an orifice passage.
[0003]
Further, the applicant of the present application has applied for a liquid seal vibration isolator in which a conical mount is integrated with an elastic wall that constitutes a part of a liquid chamber of a cylindrical bush as an elastic main body (Japanese Patent Application No. 2000). -284387). When integrated in this way, vibrations in the biaxial directions orthogonal to each other can be absorbed by the cylindrical bush portion, and further, vibrations in the direction orthogonal to these can be absorbed by the conical mount portion, so that three axes orthogonal to each other with a single device Can absorb vibrations in all directions. In the following description, the vertical direction in the illustrated state of FIG. 1 (front-rear direction when mounted on the vehicle body), the left-right direction (left-right direction when mounted on the vehicle body), and the vertical direction in FIG. The X-axis direction, Y-axis direction, and Z-axis direction are assumed.
[0004]
[Problems to be solved by the invention]
By the way, when the cylindrical bush portion and the conical mount portion are integrated as described above, the cylindrical bush portion and the conical mount portion each have a membrane resonance portion. The dynamic spring characteristics in the medium and high frequency range are determined by the coupling of each membrane resonance in the mold bush and conical mount, resulting in a low dynamic spring in a wide range, or the minimum value of the dynamic spring constant (hereinafter referred to as the dynamic spring bottom) at a specific frequency. Similarly, it is difficult to form a maximum value of the dynamic spring constant (called a dynamic spring peak), and it is desirable to make this possible. Therefore, the present invention aims to realize such a demand. Here, the middle-high frequency range means a frequency range of about 200 to 1000 Hz.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, a first invention relating to a liquid seal vibration isolator according to the present application includes a first attachment member attached to either the vibration generating side or the vibration receiving side, and the other To the side A second mounting member to be attached; and a substantially conical elastic main body connecting the first and second mounting members; a liquid chamber having the elastic main body as a part of an elastic wall; The liquid chamber is partitioned into a main liquid chamber and a sub liquid chamber by a partition member, and a conical mount portion is provided in which the main liquid chamber and the sub liquid chamber are communicated by a first orifice passage. A plurality of side liquid chambers sharing the elastic main body part as a part of the elastic wall are provided on the outer peripheral portion at a predetermined interval in the circumferential direction, and a cylinder is formed by connecting these side liquid chambers with a second orifice passage. In the liquid seal vibration isolator provided with a mold bush part, the conical mount part and the cylindrical bush part generate film resonances at different specific frequencies, and the film resonance occurs in the conical mount part. Of the dynamic spring constant Alternatively, a low dynamic spring characteristic is obtained by coupling a local minimum value and a local maximum value or a local minimum value of a dynamic spring constant generated by an inherent membrane resonance in the cylindrical bush portion so as to interfere with each other. .
[0006]
The specific membrane resonance in the conical mount portion and the cylindrical bush portion is obtained by measuring the dynamic spring characteristics by filling the liquid only in the liquid chamber on either side of the conical mount portion or the cylindrical bush portion. It is a membrane resonance having an inherent resonance frequency and dynamic spring characteristics.
[0007]
According to a second aspect of the present invention, in the first aspect, the cylindrical bush portion forms a maximum value of a dynamic spring constant at a specific frequency by a plurality of membrane resonances, and further forms a minimum value on a higher frequency side than that. At the same time, the conical mount portion generates a membrane resonance that forms a minimum value of the dynamic spring constant in the vicinity of the natural frequency that gives the maximum value and at a lower frequency side.
[0008]
According to a third aspect of the present invention, in the first aspect, the cylindrical bush portion forms a maximum value of a dynamic spring constant by an inherent membrane resonance, and the conical mount portion also forms a minimum value of the dynamic spring constant by an inherent membrane resonance. In addition, with respect to the specific frequency at which the bush-side maximum value is formed, there is a specific frequency at which the mount-side minimum value is formed in the vicinity and at a higher frequency side.
[0009]
According to a fourth aspect of the present invention, in any one of the first to third aspects, an elastic film for absorbing the internal pressure fluctuation of the main liquid chamber is provided facing the main liquid chamber of the conical mount portion. .
[0010]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a disk member that interlocks with the first mounting portion is provided in the main liquid chamber of the conical mount portion.
[0011]
【The invention's effect】
According to the first invention, the maximum value or the minimum value of the dynamic spring constant generated by the inherent membrane resonance in the conical mount portion, and the maximum value of the dynamic spring constant generated by the inherent membrane resonance in the cylindrical bush portion or Since the local minimum and the minimum value are coupled so as to interfere with each other, the dynamic spring peak generated by the inherent membrane resonance in the cylindrical bush portion or the conical mount portion is pulled down by the dynamic spring bottom generated by the inherent membrane resonance on the other side. As a result, a low dynamic spring can be achieved over a wide range in the middle and high frequency range.
[0012]
According to the second invention, the cylindrical bush portion is provided with a plurality of membrane resonance portions, each of which has a dynamic spring peak at a specific frequency and a dynamic spring bottom on a higher frequency side, so that the membrane resonance of the conical mount portion is By forming the dynamic spring bottom on the lower frequency side than the specific frequency of the dynamic spring peak, the dynamic spring peak on the cylindrical bush portion side is lowered. In addition, since the dynamic spring peak occurs on the lower frequency side than the dynamic spring bottom of the cylindrical bush portion, the dynamic spring is reduced in a wide frequency range.
[0013]
According to the third aspect of the present invention, when the dynamic spring peak due to the inherent membrane resonance in the cylindrical bush portion occurs on the lower frequency side than the dynamic spring bottom due to the inherent membrane resonance in the conical mount portion, the movement of the membrane resonance in the conical mount portion. Lower the dynamic spring peak of the cylindrical bush by lowering the spring at the spring bottom.
[0014]
Moreover, since the membrane resonance of the cylindrical bush portion having the dynamic spring peak occurs earlier on the low frequency side than the membrane resonance on the conical mount portion side having the dynamic spring bottom, the membrane resonance energy on the cylindrical bush portion side is increased. In order to strengthen the membrane resonance in the conical mount portion, the dynamic spring bottom on the conical mount portion side is amplified, and a dynamic spring bottom occurs in the coupled dynamic spring characteristics. Therefore, it is possible to form the dynamic spring bottom at a specific frequency.
[0015]
According to the fourth invention, in any one of the inventions, since the elastic film for absorbing the internal pressure fluctuation of the main liquid chamber is provided facing the main liquid chamber of the conical mount portion, the entire dynamic spring characteristics Can be further reduced.
[0016]
According to the fifth invention, in any one of the above inventions, since the disk member interlocked with the first mounting portion is provided in the main liquid chamber of the conical mount portion, the disk member is used as the main liquid together with the first mounting portion. By vibrating in the room, liquid column resonance is generated, and coupled with the membrane resonance of the elastic main body, further lowering the dynamic spring in the middle and high frequency range.
It is characterized by that.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment configured as an engine mount of a vehicle will be described with reference to the drawings. 1 is a plan view showing the engine mount from the upper side when the vehicle body is mounted in the Z-axis direction, FIG. 2 is a cross-sectional view of the entire 90 ° difference (cross-sectional view taken along line 2-2 in FIG. 1), and FIG. FIG. 4 is a perspective view of the insertion body in which the first mounting portion and the elastic member are integrated. In the following description, the vertical direction (front-rear direction when mounted on the vehicle body) in FIG. 1 is the X-axis direction, and the left-right direction (left-right direction when mounted on the vehicle body) is the Y-axis direction. Further, the vertical direction in FIG. 2 (the same applies when the vehicle is mounted) is defined as the Z-axis direction.
[0018]
In these drawings, the engine mount is formed by integrally forming a conical mount portion 1 and a cylindrical bush portion 2, and the conical mount portion 1 includes a first mounting member 3 attached to the engine side, A second mounting member 5 configured as a rigid cylindrical outer frame that surrounds the periphery with a space therebetween, and a substantially conical elasticity that connects between the first mounting member 3 and the second mounting member 5. It has a main body 7. One end of a stopper 4 having a substantially L-shaped cross section is attached to the first attachment member 3. A vehicle body side bracket 6 attached to the vehicle body side is welded to the second attachment member 5.
[0019]
The first mounting member 3 has an axial direction that coincides with the Z-axis direction that is the main vibration input direction in the conical mount portion 1, and the portion embedded in the elastic body portion 7 has a cylindrical shape, The lower part is made thinner than the step part provided in the upper part, and it extends long along the Z-axis direction. The portion of the first mounting member 3 that protrudes from the elastic main body portion 7 forms a flat portion and is connected to the stopper 4.
[0020]
The substantially conical space formed by the elastic main body portion 7 forms a liquid chamber and is opened downward in FIGS. 2 and 3. A partition member 8 and a diaphragm 9 are attached to the open portion, and the inner wall of the elastic main body portion 7 Between the partition members 8, the elastic main body portion 7 is a main liquid chamber 10 having a part of the elastic wall, and between the partition member 8 and the diaphragm 9 is a sub liquid chamber 11, and the partition member 8 divides the liquid chamber into the main liquid chamber 10. And sub-liquid chamber 11.
[0021]
The partition member 8 includes a resin-made cylindrical portion 12 made of resin as appropriate and a pressing plate 13 having a smaller diameter and overlapping the surface of the auxiliary liquid chamber 11, and the first orifice is interposed between the cylindrical portion 12 and the pressing plate 13. A passage 15 is formed, and functions as a damping orifice that constantly communicates between the main liquid chamber 10 and the sub liquid chamber 11 and absorbs vibrations in a small amplitude low frequency region during general traveling of the vehicle.
[0022]
The elastic main body portion 7 constituting the conical mount portion 1 and the cylindrical bush portion 2, and end walls and elastic partition walls, which will be described later, are all continuously and integrally formed of the same single elastic member. A single insertion member 17 (FIG. 4) formed integrally with one mounting portion 3 is provided, and a pocket portion 18 is provided on the side surface so as to open sideways, and a cylindrical bush portion 2 described later is provided. It has a liquid chamber space.
[0023]
The cylindrical bush portion 2 is formed with a plurality of side liquid chambers 20 whose outer wall is a part of the elastic wall on the outer periphery of the elastic main body portion 7. The side liquid chamber 20 is open to the side and forms a substantially triangular space. The side liquid chamber 20 is integrally formed with the elastic main body 7 and is fitted into an end wall 21 and a side opening that extend in a substantially horizontal direction. The resin liquid chamber cover 22 to be joined is sealed.
[0024]
The liquid chamber cover 22 is brought into close contact with the inner peripheral surface of the second mounting member 5 in an arc shape with a width of approximately ¼ circumference. A groove 23 extending in the circumferential direction is provided on a surface (hereinafter referred to as an outer surface) of the liquid chamber cover 22 that is in contact with the second mounting member 5 and is opened to the second mounting member 5 side. A second orifice passage 24 is formed between the two. The second orifice passage 24 is formed in the circumferential direction along the inner surface of the second mounting member 5, and always communicates between the pair of side liquid chambers 20, 20. It functions as a similar damping orifice.
[0025]
Further, the cylindrical bush portion 2 is adjacent to the side liquid chamber 20. Tickling part 25 is formed. As shown in FIG. 1, the cylindrical bush portion 2 is formed on the outer circumference of the elastic main body portion 7 in the circumferential direction with the side liquid chambers 20 and the adjacent straight portions 25 each having a total of two chambers at 90 ° intervals. The paired side liquid chambers 20 and 20 and the straight portions 25 and 25 are located on the opposite side at an interval of 180 ° with respect to the central portion. The pair of side liquid chambers 20, 20 are arranged on the X axis which is the main vibration input direction in the cylindrical bush 2.
[0026]
The straight portion 25 is opened upward in FIG. 2, and is surrounded by an elastic portion including a thin portion 26, an elastic partition wall 27, and a side wall 28. The thin portion 26 is formed by forming a bottom portion of the straight portion 25 to partition the main liquid chamber 10 and a part of the elastic main body portion 7 as a special thin portion. It is set so that membrane resonance is generated by vibration input in the middle frequency range.
[0027]
The elastic partition wall 27 partitions the side liquid chamber 20 and is formed as a thin elastic wall which is formed in the radial direction as shown in FIG. 3 and has the same membrane resonance characteristics as the thin portion 26. Has been. The side wall 28 is in close contact with the inner surface of the second mounting member 5 and is formed integrally with the thin portion 26 and the elastic partition wall 27. A groove 29 similar to the groove 23 is formed on the outer surface of the side wall 28 (FIG. 4) and forms a part of the second orifice passage 24.
[0028]
Figure 2 As shown in FIG. 4, the tip of the elastic main body 7 and one end of the side wall 28 form an enlarged portion 30 in which a ring 31 having a U-shaped cross section is embedded and integrated. Only the lower surface of the ring 31 is exposed and is in contact with the upper surface of the partition member 8 to be positioned. The enlarged portion 30 is in close contact with the inner surface of the second mounting member 5 and the lower end portion of the liquid chamber cover 22 to be sealed.
[0029]
A ring 32 having a substantially S-shaped cross section is also embedded and integrated on the upper end sides of the end wall 21 and the side wall 28, and is fixed by a caulking portion 33 in which the upper end of the second mounting member 5 is bent inward. . The end wall 21, the thin-walled portion 26, the elastic partition wall 27, the side wall 28, and the enlarged portion 30 are all continuously and integrally formed of the same elastic member as that of the elastic main body portion 7.
[0030]
A part of the second mounting member 5 below the partition member 8 is formed with an inwardly folded portion 35, and the outer peripheral edge of the partition member 8 is sandwiched and fixed between the rings 31. A further inner end 36 of the folded portion 35 is folded downward to form an annular wall, and an operating space for the diaphragm 9 is secured inside thereof.
[0031]
When a receiving side member 37 having a substantially U-shaped cross section is welded to an intermediate portion in the vertical direction in the figure on the outer side surface of the second mounting member 5, when an excessive load is input to the first mounting member 3 side, The end of the moving stopper 4 is abutted and received.
[0032]
In order to assemble this engine mount, the diaphragm 9 is put inside the second mounting member 5 and the outer peripheral portion thereof is placed on the folded portion 35, and the partition member 8 The outer peripheral portion of the cylindrical portion 12 is placed on the enlarged portion formed on the outer periphery of the diaphragm 9, and the outer peripheral portion of the diaphragm 9 is sandwiched between the outer peripheral portion of the partition member 8 and the folded portion 35. .
[0033]
continue Interpolant 17 Into the second mounting member 5. At this time, the side opening portion of the side liquid chamber 20 is previously closed with the liquid chamber cover 22. Elastic molded body 34 The ring 30 is overlaid on the outer peripheral portion of the partition member 8 stacked on the outer peripheral portion of the folded portion 35, and the second mounting member 5 is The edge The ring 32 is fixed by the crimping portion 33 by bending inward to form the crimping portion 33. At this time, the outer periphery of the partition member 8 is a ring 31 And is fixed and sealed by the outer peripheral portion of the diaphragm 9 sandwiched between the folded portions 35. In this assembly process, the main liquid chamber 10 , Secondary liquid chamber 11 The incompressible liquid is sealed in the side liquid chamber 20 by a known method.
[0034]
Next, the operation of this embodiment will be described. If the main vibration input direction of the conical mount portion 1 is arranged in the Z-axis direction and the main vibration input direction of the cylindrical bush portion 2 is arranged in the X-axis direction, the vibration in the Z-axis direction is the first vibration in the conical mount portion 1. High attenuation is caused by liquid column resonance of one orifice passage 15. In addition, with respect to vibration in the X-axis direction, liquid moves between the front and rear side liquid chambers 20 and 20 when the vehicle body is mounted, and thus liquid column resonance is generated, resulting in high attenuation. .
[0035]
Further, since the thin portion 26 is provided, the thin portion 26 undergoes membrane resonance at a frequency in a specific medium frequency region, and by this membrane resonance, a low dynamic spring is generated in the specific medium frequency region, whereby each XZ in the medium frequency region. Can absorb the vibration of direction. Accordingly, each vibration in the X and Z-axis directions can be reduced based on the liquid flow between the liquid chambers, and the dynamic spring can be reduced by membrane resonance in the medium frequency region, and at the same time can be efficiently reduced with a single device.
[0036]
FIG. 12 is a graph showing the dynamic spring characteristics of this embodiment. The vertical axis indicates the dynamic spring constant, the horizontal axis indicates the frequency of the input vibration, the characteristic curve (1) of this embodiment, and the conical mount portion 1 as a reference. Characteristic curve when only liquid is sealed ▲ 3 ▼ And And Characteristic curve when liquid is sealed only in cylindrical bush 2 ▲ 2 ▼ Is also written.
[0037]
First, when liquid is sealed only in the conical mount 1, the characteristic curve ▲ 3 ▼ As shown in FIG. 4, a dynamic spring bottom B1 is generated by membrane resonance in the thin portion 26 of the elastic main body portion 7 at a frequency a, and thereafter a dynamic spring peak P2 is generated by membrane resonance in the thick portion 7 at a relatively high frequency d. In addition, when liquid is sealed only in the cylindrical bush 2, the characteristic curve ▲ 2 ▼ As shown in FIG. 3, the dynamic spring peak P1 due to the membrane resonance of the end wall 21 at the frequency b and the dynamic spring bottom B2 due to the membrane resonance of the elastic partition wall 27 are generated at a frequency c higher than that and lower than the frequency d. . It is assumed that the frequency increases in the order of a <b <c <d.
[0038]
On the other hand, in this embodiment, since the liquid is sealed in each liquid chamber of the conical mount portion 1 and the cylindrical bush portion 2, the characteristics are coupled to these characteristic curves (2) and (3). The characteristic curve {circle over (1)} is obtained. In this case, by setting the dynamic spring bottom B1 to be generated at a frequency lower than the dynamic spring peak P1, the characteristic curve {circle around (1)} between the frequencies ab is relatively flat that averages the dynamic spring peak P1 and the dynamic spring bottom B1. Therefore, a low dynamic spring is obtained only by lowering the dynamic spring peak P1.
[0039]
In addition, by generating the dynamic spring bottom B2 of the characteristic curve {circle around (2)} at a frequency c lower than the frequency d of the dynamic spring peak P2, the characteristic curve {circle around (2)} that pushes down the dynamic spring peak P2 and descends past the dynamic spring peak P1. The dynamic spring constant is lower than the characteristic curve (3) on the lower frequency side than the intersection e of the characteristic curve (3) that rises past the dynamic spring bottom B1, and the dynamic spring constant is lower than the characteristic curve (2) on the higher frequency side. make low.
[0040]
Therefore, a wide frequency range from the dynamic spring peak P1 frequency b to the frequency d of the dynamic spring peak P2 can be lowered on the high frequency side, and eventually the characteristic curve {circle around (1)} in the normal range below the frequency d required to reduce vibration. Can be sufficiently lowered. In addition, in this embodiment, since the spring is remarkably low even on the higher frequency side than the frequency d, the performance more than required can be exhibited.
[0041]
Next, a second embodiment will be described. 5 is a plan view of the insertion body of the present embodiment, FIG. 6 is a sectional view taken along line 6-6 of FIG. 5, and FIG. 6 FIG. 7 is a sectional view taken along line 7-7. Note that this embodiment differs from the previous embodiment only in a part of the structure such as the insert, and the other parts are the same as in the previous embodiment. Therefore, the description of these parts is omitted and is the same as the previous embodiment. Common symbols are used for the parts.
[0042]
The insert 17 in the present embodiment is characterized in that only the elastic partition wall 27 forms a solid structure without a straight portion. That is, unlike the previous embodiment, the elastic partition wall 27 extends to the opposite side on the Y-axis at an interval of 180 ° with respect to the central portion, as shown in FIG. 18 is divided forward and backward.
[0043]
The distal end portion 40 protrudes slightly in the radial direction from the inner diameter of the second attachment portion 5, and the connection end portion 41 of the liquid chamber cover 22 covering the pocket portion 18 is overlapped on the distal end portion 40, so that the second attachment portion 5. When press-fitted in, the elastic partition wall 27 is compressed inward to insert 17 Closely fit into the second mounting portion 5. As a result, the liquid chamber cover 22 is brought into close contact with the inner surface of the second mounting portion 5 to cover the pocket portion 18 in a liquid-tight manner, and the seat portion 42 is also brought into close contact with the distal end portion 40. Portion 41 is sealed fluid-tight.
[0044]
The liquid chamber cover 22 is brought into close contact with the inner peripheral surface of the second mounting member 5 in an arc shape with a width of about ½ circumference. A groove serving as the second orifice passage 24 is formed on the outer surface of the liquid chamber cover 22 as in the previous embodiment, and the front and rear side liquid chambers 20 formed by covering the front and rear pocket portions 18 with the liquid chamber cover 22. They communicate with each other.
[0045]
The upper part of the elastic partition wall 27 is formed integrally with the elastic main body part 7 and continues to the disk-shaped end wall 21 extending in the substantially horizontal direction, and the lower part is also continuous to the elastic main body part 7. The elastic partition wall 27 is formed as a thin elastic wall having the same membrane resonance characteristics as the elastic main body 7.
[0046]
Next, the operation of this embodiment will be described. Similarly to the previous embodiment, the cylindrical bush portion 2 in the present embodiment also flows through the second orifice passage between the front and rear side liquid chambers 20 with respect to the vibration input in the front-rear direction (X-axis direction). Thus, the liquid column resonance can be used for attenuation.
[0047]
Further, the vibration in the left-right direction can be absorbed by the spring elasticity of the elastic partition wall 27. At this time, the elastic partition wall 27 is solid without providing a curb portion, and the end wall 21 is formed so as to form a single disk as a whole, and the elastic partition wall 27 is compressed toward the center during assembly. Therefore, the spring value in the left-right direction can be increased.
[0048]
In addition, as in the previous embodiment, vibrations can be efficiently absorbed by utilizing each membrane resonance by the elastic main body 7, the end wall 21, and the elastic partition wall 27. FIG. 13 is a graph similar to FIG. 12 showing the dynamic spring characteristics of the present embodiment. The characteristic curve (4) of this embodiment and a characteristic curve (▲) when a liquid is sealed only in the conical mount portion 1 as a reference. 5 and the characteristic curve (6) when the liquid is sealed only in the cylindrical bush portion 2 are also shown.
[0049]
First, when liquid is sealed only in the cylindrical bush portion 2, a dynamic spring peak P3 due to membrane resonance of the end wall 21 is generated at the frequency f as shown by the characteristic curve (6), and higher frequency side than that. In addition, an anti-resonance dynamic spring bottom is generated at a frequency higher than the frequency f. The elastic partition wall 27 does not resonate because the front and back are in the liquid.
[0050]
Further, when the liquid is sealed only in the conical mount portion 1, the dynamic spring bottom B4 is generated by the membrane resonance in the elastic main body portion 7 at the frequency h higher than the frequency f as shown by the characteristic curve (5). This frequency h is slightly lower than the frequency generated by the dynamic spring bottom due to the anti-resonance of the characteristic curve (6), and thereafter, the dynamic spring constant increases as the frequency becomes higher due to the anti-resonance.
[0051]
In the present embodiment, a characteristic curve (4) obtained by coupling these characteristic curves (5) and (6) is obtained. In this case, by setting the frequency of the dynamic spring bottom B4 to occur at a frequency h higher than the frequency f of the dynamic spring peak P3, the dynamic spring peak P3 is lowered to become a low dynamic spring.
[0052]
Moreover, the dynamic spring bottom B3 occurs at g, which is intermediate between the frequencies f and h. Here, the relationship between the frequencies is such that the frequencies increase in the order of f <g <h.
This dynamic spring bottom B3 is generated as a result of the dynamic spring bottom B4 being amplified by membrane resonance on the cylindrical bush portion side. That is, the membrane resonance on the cylindrical bush portion side where the dynamic spring peak P3 is first generated on the low frequency side gives the energy to the membrane resonance on the cone mount portion side which is subsequently generated on the high frequency side, so that the dynamic spring bottom B4 is amplified. Thus, a dynamic spring bottom B3 is generated as a coupled dynamic spring characteristic.
[0053]
Therefore, according to this example, the dynamic spring bottom can be formed at a specific frequency in the entire dynamic spring characteristic, and various tunings can be realized.
[0054]
FIG. 8 is a sectional view similar to FIG. 2 according to the third embodiment. This implementation Example Then, the same insert as in the first embodiment is used, and the elastic film 50 is provided on the partition member 8 to absorb the increase in the internal pressure of the main liquid chamber 10. That is, a through hole 52 is provided in the upper wall 51 formed on the upper portion of the cylindrical portion 12, and the elastic membrane 50 is fixed between the upper wall 51 and the holding plate 13 and the hydraulic pressure of the main liquid chamber 10 is fixed. Accordingly, it is provided so as to be elastically deformable, thereby absorbing the internal pressure of the main liquid chamber 10.
[0055]
The first orifice passage 15 is formed in each outer peripheral portion of the cylindrical portion 12 and the pressing plate 13 and communicates the main liquid chamber 10 and the sub liquid chamber 11. A ring 31 having a U-shaped cross section is embedded and integrated at the tip of the elastic main body 7. The ring 31 is positioned by abutting on the stepped portion 53 formed on the outer periphery of the cylindrical portion 12 constituting the partition member 8 with only the lower surface exposed, and the inner surface of the second mounting member 5 and the liquid chamber cover. The tip of the elastic main body 7 is in close contact with the lower end of the 22 and is sealed. A ring 32 is also embedded and integrated in the outer peripheral portion of the end wall 21 and is fixed by a caulking portion 33 in which the upper end of the second mounting member 5 is bent inward.
[0056]
A portion of the second mounting member 5 below the partition member 8 forms a small diameter portion 54, and a step portion 55 formed at the boundary between the small diameter portion 54 and the upper portion thereof is provided on the outer peripheral edge of the partition member 8. The ring 31 is put on. The liquid chamber cover 22 is sandwiched between the upper and lower rings 31 and 32 and fixed by an upper caulking portion 33. On the small diameter portion 54 side, the cylindrical portion 12 and the pressing plate 13 are stacked under the ring 31, and the enlarged portion formed on the outer periphery of the diaphragm 9 is further stacked on the lower end portion of the pressing plate 13 to form the crimping portion 55. It is integrated.
[0057]
In this way, in the conical mount portion 1, attenuation due to liquid column resonance in the first orifice passage 15 and the thin film portion 26 are caused. According Membrane resonance can be expected in the same manner as in the above embodiments, and if there is a large vibration input from the Z-axis direction, the elastic membrane 50 is elastically deformed and absorbs the increase in internal pressure in the main liquid chamber 10, so that the conical mount portion 1 Becomes a low dynamic spring.
[0058]
FIG. 14 is a graph showing the dynamic spring characteristics, where the vertical axis indicates the dynamic spring constant and the horizontal axis indicates the frequency. The solid line in the figure is a characteristic curve showing the dynamic spring constant change of the present embodiment, and the broken line is a characteristic curve corresponding to the comparative example in which the elastic membrane 50 is removed from the present embodiment, that is, corresponding to the first embodiment. As is clear from this graph, the present embodiment can further reduce the overall dynamic spring by the presence of the elastic membrane 50.
[0059]
FIG. 9 is a cross-sectional view similar to FIG. 8 according to the fourth embodiment, and the insert 17 includes the same as that of the second embodiment, and further includes the elastic membrane 50 of the third embodiment. In this example, the distal end side of the elastic partition wall 27 which is the radially outward side of the cylindrical bush portion 2 is fitted and fixed to the liquid chamber cover 22.
[0060]
FIG. 10 is an enlarged cross-sectional view (corresponding to a line 10-10 in FIG. 9) of this portion, and each connection end 41 of the pair of liquid chamber covers 22 outside the front end 40 of the elastic partition wall 27. In this example, a protruding portion 43 that protrudes from the seat portion 42 and fits the tip end portion 40 of the elastic partition wall 27 is provided, and an inner surface 44 of the protruding portion 43 is formed between the elastic partition walls 27. The taper is formed so as to form a taper angle α so that the space to be gradually narrowed outward.
[0061]
In this way, when the elastic partition wall 27 is elastically deformed in the front-rear direction, the spring value is set so that the amount of elastic deformation can be increased for small vibrations. When in contact, the spring value can be changed nonlinearly by restricting further elastic deformation and increasing the spring value. The spring value at the time of large vibration can be arbitrarily set by adjusting the taper angle of the inner surface 44 and the amount of inward protrusion.
[0062]
In addition, by reducing the dynamic spring of the conical mount portion 1 by the elastic membrane 50 and changing the spring value of the elastic partition wall 27 in the cylindrical bush portion 2 in a non-linear manner, it is possible to reduce the overall dynamic spring against small vibrations. it can. FIG. 15 is a graph showing the dynamic spring characteristics, where the vertical axis indicates the dynamic spring constant and the horizontal axis indicates the frequency. The solid line in the figure is a characteristic curve showing the dynamic spring constant change of the present embodiment, and the broken line is a comparative example in which the above-described fixing structure of the elastic membrane 50 and the elastic partition wall 27 is removed from the present embodiment, that is, the second embodiment. It is a characteristic curve of the equivalent. As is apparent from this graph, the present embodiment can further reduce the overall dynamic spring.
[0063]
FIG. 11 is a view similar to FIG. 8 according to the fifth embodiment. However, the insert of the second embodiment is applied. In this example, the lower end portion 60 of the first mounting member 3 is protruded into the main liquid chamber 10, and an umbrella-shaped disk member 61 is attached to the protruding end by caulking or the like. The disk member 61 is a known member for absorbing medium-frequency vibration, and vibrates integrally with the first attachment member 3 in the main liquid chamber 10. Further, the partition member 8 is provided with a first orifice passage 15, which communicates the main liquid chamber 10 and the sub liquid chamber 11.
[0064]
FIG. 16 is a graph showing the dynamic spring characteristics, where the vertical axis indicates the dynamic spring constant and the horizontal axis indicates the frequency. The solid line in the figure is a characteristic curve showing a change in the dynamic spring constant of the present embodiment, and the broken line is a characteristic curve corresponding to a comparative example in which the disk member 61 is excluded from the present embodiment, that is, a characteristic curve corresponding to the second embodiment. As is apparent from this graph, when the disk member 61 is omitted, a dynamic spring bottom B5 is generated in the vicinity of 500 Hz, which is the middle-high frequency range, by the thin elastic main body 7, and the anti-resonance rises abruptly on the high frequency side. As a result, the dynamic spring bottom B6 shifts to the higher frequency side due to the coupled resonance of the disk member 61, so that the lower dynamic spring can be achieved to the high frequency side exceeding 500 Hz.
[0065]
The present invention is not limited to the above-described embodiments, and various modifications and applications can be made within the principle of the invention. For example, it is also effective in a liquid seal vibration isolator having only the cylindrical bush portion 2 without the conical mount portion 1. In this case, in the state of use as in the above embodiments, the front and rear and left and right directions 2 The spring ratio of the direction can be controlled.
[0066]
Further, the cylindrical bush portion 2 can be arranged arbitrarily. For example, the cross-sectional direction of the elastic partition wall 27 in FIG. 7 can be arranged in the front-rear direction or the vertical direction of the vehicle body. Is different from the above.
[Brief description of the drawings]
FIG. 1 is a plan view of an engine mount according to a first embodiment.
2 is a sectional view taken along line 2-2 of FIG.
3 is a sectional view taken along line 3-3 in FIG.
[Figure 4] Interpolated body Perspective Figure
FIG. 5 is a plan view of an insert according to a second embodiment.
6 is a sectional view taken along line 6-6 in FIG.
7 is a cross-sectional view taken along line 7-7 in FIG.
8 is a cross-sectional view corresponding to FIG. 2 according to a third embodiment.
FIG. 9 is a diagram related to the fourth embodiment. 8 Equivalent
10 is a cross-sectional view corresponding to line 10-10 in FIG. 9;
FIG. 11 is a diagram related to the fifth embodiment. 8 Equivalent
FIG. 12 is a graph showing the effects of the first embodiment.
FIG. 13 is a graph showing the effects of the second embodiment.
FIG. 14 is a graph showing the effects of the third embodiment.
FIG. 15 is a graph showing the effects of the fourth embodiment.
FIG. 16 is a graph showing the effects of the fifth embodiment.
[Explanation of symbols]
1: Conical mount portion, 2: Cylindrical bush portion, 3: First mounting member, 5: Second mounting member, 7: Elastic body portion, 8: Partition member, 10: Main liquid chamber, 11: Sub Liquid chamber, 15: first orifice passage, 17: insert, 20: side liquid chamber, 21: end wall, 22: liquid chamber cover, 24: second orifice passage, 25: curb portion, 27 : Elastic partition wall, 40: tip portion, 41: connection end portion, 42: seat portion, 50: elastic membrane, 61: disk member

Claims (5)

A first attachment member attached to either the vibration generating side or the vibration receiving side, a second attachment member attached to either one of the two sides, and a substantially conical shape connecting the first and second attachment members A liquid chamber having the elastic body portion as a part of the elastic wall, and partitioning the liquid chamber into a main liquid chamber and a sub liquid chamber by a partition member, and the main liquid chamber Providing a conical mount that communicates between the secondary liquid chambers by a first orifice passage;
A plurality of side liquid chambers that share the elastic main body portion as a part of the elastic wall are provided at predetermined intervals in the circumferential direction on the outer peripheral portion of the elastic main body portion, and a space between the side liquid chambers is a second orifice passage. In the liquid seal vibration isolator provided with a cylindrical bush by contacting
In the conical mount portion and the cylindrical bush portion, a membrane resonance is generated at different natural frequencies, respectively.
The maximum value or the minimum value of the dynamic spring constant generated by the inherent membrane resonance in the conical mount portion and the maximum value or the minimum value of the dynamic spring constant generated by the inherent membrane resonance in the cylindrical bush portion are mutually A liquid seal vibration isolator characterized by being coupled so as to interfere with each other to obtain a low dynamic spring characteristic. The cylindrical bush portion forms a local maximum value of a dynamic spring constant at a specific frequency due to a plurality of membrane resonances, and further forms a local minimum value on a higher frequency side, and the conical mount portion includes the local maximum value. 2. The liquid seal vibration isolator according to claim 1, wherein a membrane resonance is generated that forms a minimum value of a dynamic spring constant in the vicinity of a natural frequency that gives a low frequency and on a lower frequency side. The cylindrical bush portion forms the maximum value of the dynamic spring constant due to the inherent membrane resonance, and the conical mount portion also forms the minimum value of the dynamic spring constant due to the inherent membrane resonance, and the maximum value on the bush side is formed. 2. The liquid seal vibration isolator according to claim 1, wherein there is a specific frequency at which the minimum value on the mount side is formed in the vicinity and at a higher frequency side than the specific frequency. The liquid seal vibration isolator according to any one of claims 1 to 3, further comprising an elastic film facing the main liquid chamber of the conical mount portion to absorb fluctuations in internal pressure of the main liquid chamber. . The liquid seal vibration isolator according to any one of claims 1 to 4, wherein a disk member interlocking with the first mounting portion is provided in a main liquid chamber of the conical mount portion.

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