JP2015059580A - Liquid-sealed type vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid-sealed type vibration control device capable of improving attenuation performance in a low frequency region.SOLUTION: A third orifice 46 having one end communicated with a second orifice 45 has the other end communicated with an auxiliary liquid chamber 42 or a main liquid chamber 41 with which a first orifice 44 is communicated. When fluctuation of liquid pressure is generated in the main liquid chamber 41 and the auxiliary liquid chamber 42, liquid flow of the third orifice 46, in addition to liquid flow of the second orifice 45, is imparted to a valve member 20. The liquid flow of the second orifice 45 and the third orifice 46 is used as actuating force of the valve member 20, and the actuating force of the valve member 20 can be increased compared to the case where the third orifice 46 is not formed. As a result, the second orifice 45 can be closed from a low frequency region, and therefore, the attenuation performance in the low frequency region can be improved.

Description

  The present invention relates to a liquid-filled vibration isolator, and more particularly to a liquid-filled vibration isolator that can improve damping performance in a low frequency range.

  As a vibration isolator that supports a vibration source such as an engine on a vehicle body, for example, a liquid-filled vibration isolator disclosed in Patent Document 1 is known. The liquid-filled vibration isolator disclosed in Patent Literature 1 includes a first fixture attached to the vibration source side, a second fixture attached to the vehicle body side (support side), a first fixture, and a second attachment. And an anti-vibration base interposed between the components.

  With reference to FIG. 12, a liquid-filled vibration isolator 100 disclosed in Patent Document 1 will be described. FIG. 12 is a schematic view of a conventional liquid-filled vibration isolator 100. As shown in FIG. 12, the liquid-filled vibration isolator 100 includes a main liquid chamber 101 in which a vibration isolating base (not shown) forms part of the chamber wall, and diaphragms 102 and 103 that form part of the chamber wall. A first sub liquid chamber 104 and a second sub liquid chamber 105 are provided. The first orifice 106 communicates the main liquid chamber 101 and the first sub liquid chamber 104, and the second orifice 107 communicates the main liquid chamber 101 and the second sub liquid chamber 105. The second orifice 107 is set so that a liquid resonance phenomenon occurs in a higher frequency range than the first orifice 106, and is configured to be opened and closed by a valve member 108 made of a rubber-like elastic film. The valve member 108 opens and closes the second orifice 107 by the operating force of the liquid flowing through the second orifice 107.

  Next, the actuation force of the valve member 108 by the liquid will be described with reference to FIG. FIG. 13 is a diagram (simulation result) showing the operating force of the valve member 108 by the liquid flowing through the second orifice 107. In this simulation, excitation with a large amplitude that affects the riding comfort of the vehicle (amplitude ± 0.5 mm in this experiment) and excitation with a small amplitude that assumes idling vibration when the vehicle is stopped (amplitude ± 0 in this experiment) .1 mm) to determine the operating force. In FIG. 13, the broken line indicates the operating force of the valve member 108 necessary for opening and closing the second orifice 107. The arrow S region above the broken line indicates that the valve member 108 closes the second orifice 107 by the operating force of the liquid. Further, the arrow O region below the broken line indicates that the valve member 108 opens the second orifice 107 because the operating force due to the liquid is small (same in FIG. 8).

  In the case of vibration input with small amplitude such as idle vibration when the vehicle is stopped (amplitude ± 0.1 mm), the frequency region (S region) in which the second orifice 107 is closed by the valve member 108 is narrow, so in other frequency regions The second orifice 107 is opened, and the liquid flows through the second orifice 107. Thereby, the damping performance by the second orifice can be ensured.

  On the other hand, in the case of a vibration input having a large amplitude that affects the riding comfort (amplitude ± 0.5 mm), the fluid flow of the second orifice 107 increases and the valve member 108 is bent and deformed, so that the second orifice 107 is closed. The frequency range (S region) becomes wider. As a result, it is possible to obtain a damping performance due to the liquid flowing through the first orifice 106 (see FIG. 12).

JP 2012-189166 A

  However, the above-described technique has a problem that the second orifice is not blocked in a low frequency range in a vibration input having a large amplitude that affects riding comfort. If the second orifice is not blocked in the low frequency region, there arises a problem that the attenuation performance in the low frequency region is deteriorated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a liquid-filled vibration isolator capable of improving attenuation performance in a low frequency range.

Means for Solving the Problems and Effects of the Invention

  In order to achieve this object, according to the liquid-filled vibration isolator according to claim 1, the first fixture is provided on one side of the vibration source side or the support side, and the second fixture is provided on the other side of the vibration source side or the support side. Is attached, and an anti-vibration base composed of a rubber-like elastic body is interposed between the first fixture and the second fixture. The anti-vibration base constitutes a part of the chamber wall of the main liquid chamber, and the diaphragm constituted by the rubber-like elastic film constitutes a part of at least two sub liquid chambers. Liquid is sealed in the main liquid chamber and the sub liquid chamber, and any one of the sub liquid chambers and the main liquid chamber communicate with each other through the first orifice. Any two liquid chambers of the main liquid chamber and the sub liquid chamber are communicated by the second orifice. The second orifice is formed in a partition that partitions one of the sub liquid chambers from the main liquid chamber, and is set to resonate in a higher frequency range than the first orifice. A valve member made of a rubber-like elastic membrane is held by the partition, and the second orifice is opened and closed by the valve member.

  When vibration is input to the first fixture or the second fixture, the vibration-proof base is elastically deformed, causing fluid pressure fluctuations in the main liquid chamber and the sub liquid chamber. The third orifice whose one end communicates with the second orifice communicates with the liquid flow of the second orifice because the other end communicates with either the sub liquid chamber or the main liquid chamber with which the first orifice communicates. The liquid flow can be applied to the valve member. Since the liquid flow in the second orifice and the third orifice becomes the operating force of the valve member, the operating force of the valve member can be increased as compared with the case where the third orifice is not formed. As a result, since the second orifice can be closed from the low frequency range, the attenuation performance in the low frequency range can be improved.

  According to the liquid-filled vibration isolator according to claim 2, the third orifice is set to resonate in a lower frequency range than the second orifice. Therefore, in addition to the effect of the first aspect, the resonance performance of the liquid flowing through the third orifice has an effect of improving the attenuation performance in a lower frequency region than the second orifice.

  According to the liquid-filled vibration isolator of claim 3, the second orifice and the third orifice are formed on one axial end face of the partition. By consolidating the second orifice and the third orifice, the other axial end face of the partition can be effectively utilized. Therefore, in addition to the effect of Claim 1 or 2, there is an effect that the space can be effectively utilized.

  According to the liquid-filled vibration isolator according to the fourth aspect, the third orifice has one of the secondary liquid chambers or the other end communicating with the main liquid chamber opening at the radially outer end face of the partition. Therefore, in addition to the effect of the third aspect, there is an effect that the third orifice is less likely to be restricted by the auxiliary liquid chamber or the diaphragm. In addition, since the cross-sectional area, length, and cross-sectional circumference of the third orifice can be easily set, there is an effect that the degree of freedom in designing the third orifice can be improved.

It is an axial sectional view of the liquid filled type vibration isolator in the first embodiment of the present invention. It is an exploded three-dimensional view of a partition. It is an exploded three-dimensional view of a partition. (A) is a plan view of the partition body, (b) is a side view of the partition body, (c) is a bottom view of the partition body, and (d) is a front view of the partition body. is there. It is sectional drawing of the partition main body in the VV line | wire of Fig.4 (a). (A) is a plan view of the valve member, (b) is a side view of the valve member, (c) is a bottom view of the valve member, and (d) is a VId-VId line in FIG. 6 (a). It is sectional drawing of the valve member in. It is a schematic diagram of a liquid enclosure type vibration isolator. It is a figure which shows the operating force of a valve member. It is a figure which shows a dynamic spring constant. It is a figure which shows an attenuation coefficient. It is a schematic diagram of the liquid filling type vibration isolator in 2nd Embodiment. It is a schematic diagram of the conventional liquid enclosure type vibration isolator. It is a figure which shows the operating force of the valve member by a liquid.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is an axial sectional view of a liquid filled type vibration damping device 1 according to a first embodiment of the present invention. The liquid-filled vibration isolator 1 is an engine mount that elastically supports an automobile engine, and includes a first attachment 2 that is attached to the engine that is a vibration source, and a cylindrical second attachment that is attached to the vehicle body on the support side. And an anti-vibration base 5 made of a rubber-like elastic body interposed between the first fixture 2 and the second fixture 7 and connected to each other. Note that the liquid-filled vibration isolator 1 shown in FIG. 1 shows a no-load state.

  The first fixture 2 is a boss fitting disposed on the axial center of the second fixture 7, and is provided with a stopper portion 3 that protrudes in a flange shape toward the radially outer side. A bolt hole 2a is formed in the axial center of the first fixture 2, and the first fixture 2 is attached to the engine side via a bolt (not shown) screwed into the bolt hole 2a.

  The second fixture 7 includes a cylindrical tubular fitting 8 in which the vibration-proof base 5 is vulcanized and a cup-shaped bottom fitting 9 disposed at one axial end of the tubular fitting 8. The A mounting bolt (not shown) projects from the bottom metal fitting 9 and is attached to the vehicle body via the mounting bolt. The lower end of the cylindrical metal fitting 8 is fixed by caulking to the upper end opening of the bottom metal fitting 9 by the caulking portion 8 a, and the upper end is fixed by caulking to the stopper metal fitting 4. The stopper fitting 4 is a member that exerts a stopper action between the stopper fitting 4 and the stopper portion 3 of the first fixture 2.

  The anti-vibration base 5 is formed in a substantially umbrella shape, and the upper end is vulcanized and bonded to the first fixture 2 and the lower end is vulcanized and bonded to the upper end opening of the cylindrical fitting 8. The anti-vibration base 5 has a rubber film-like seal wall 6 that covers the inner peripheral surface of the cylindrical fitting 8 and is coupled to the lower end.

  The second fixture 7 is attached with a first diaphragm 30 that is disposed opposite to an end surface (lower surface) in the axial direction X of the vibration-proof base 5. The first diaphragm 30 includes a circular film portion 31 that generates a displacement and an outer peripheral portion 32 that is coupled to the outer periphery of the film portion 31, and is integrally configured from a flexible rubber-like elastic film. An annular reinforcing metal fitting 33 is vulcanized and bonded to the outer peripheral portion 32, and is fixed to the caulking portion 8 a via the reinforcing metal fitting 33.

  Liquid is sealed in a sealed space defined by the vibration isolating base 5, the cylindrical fitting 8 and the first diaphragm 30, thereby forming a liquid chamber. The liquid chamber is partitioned by a partition 10 into a main liquid chamber 41 in which the vibration isolating substrate 5 forms part of the chamber wall and a first sub liquid chamber 42 in which the first diaphragm 30 forms part of the chamber wall. It is done.

  The partition body 10 is formed in a circular shape when viewed in the axial direction X and is fitted to the inner periphery of the cylindrical metal member 8 via the seal wall portion 6, and the axial direction X of the partition body body 11. And a partition receiving plate 15 disposed in contact with the end surface (lower surface). The partition receiving plate 15 is a disk-shaped metal fitting having an opening (not shown) penetrating in the thickness direction (axial direction X), and an outer peripheral portion thereof is fixed to the caulking portion 8 a together with the reinforcing metal fitting 33. The partition body 11 is held between the stepped portion 5 a provided at the boundary between the vibration isolating base 5 and the seal wall portion 6 and the partition receiving plate 15 in a state sandwiched in the axial direction X. The partition 10 is provided with a second sub liquid chamber 43 partitioned from the first sub liquid chamber 42 by the second diaphragm 18 on the first sub liquid chamber 42 side, and a rubber-like elastic film on the main liquid chamber 41 side. The valve member 20 comprised from these is provided.

  Next, the partition 10 will be described with reference to FIGS. 2 and 3 are exploded views of the partition 10. 4A is a plan view of the partition body 11, FIG. 4B is a side view of the partition body 11, and FIG. 4C is a bottom view of the partition body 11. (D) is a front view of the partition body 11. FIG. 5 is a cross-sectional view of the partition body 11 taken along the line V-V in FIG. 6 (a) is a plan view of the valve member 20, FIG. 6 (b) is a side view of the valve member 20, FIG. 6 (c) is a bottom view of the valve member 20, and FIG. These are sectional drawings of the valve member 20 in the VId-VId line | wire of Fig.6 (a).

  As shown in FIG. 2, FIG. 4A and FIG. 5, the partition body 11 is a member formed in a substantially cylindrical shape, and a large-diameter concave portion 11a having a substantially circular shape in plan view has an upper surface (end surface in the axial direction). A small-diameter concave portion 11b having a smaller diameter than the large-diameter concave portion 11a is formed in a stepped shape on the axial end surface of the large-diameter concave portion 11a. The bottom surface portion 12 (axial end portion) of the small-diameter concave portion 11b has a circular wall portion 12a projecting upward in the axial direction in plan view, and is substantially in the center of the bottom surface portion 12 radially inward of the wall portion 12a. In addition, an opening 12b that penetrates the bottom surface portion 12 in the thickness direction (axial direction) is formed.

  The small-diameter concave portion 11b is a portion where the valve member 20 is accommodated, and the large-diameter concave portion 11a is a portion where the substantially disc-shaped lid member 16 is fitted and fixed. As shown in FIGS. 2 and 3, the lid member 16 has an opening 16a penetrating through the lid member 16 in the thickness direction (axial direction) at a substantially center, and a circular wall portion 16b in the axial direction when viewed from the bottom. It protrudes downward.

  Next, the valve member 20 will be described with reference to FIG. As shown in FIG. 6A to FIG. 6D, the valve member 20 includes a flexible membrane portion 21 formed in a thin film shape and the entire circumference of the outer circumference of the flexible membrane portion 21. The outer peripheral portion 22 formed to be thicker than the flexible membrane portion 21 and the communication hole 21a penetrating the flexible membrane portion 21 in the thickness direction are provided, and the flexible membrane portion 21 and the outer peripheral portion are provided. 22 is integrally formed from a rubber-like elastic body. When the valve member 20 is accommodated in the small-diameter recess 11b (see FIG. 2) and the lid member 16 is fitted and fixed in the large-diameter recess 11a, the outer peripheral portion 22 is attached to the walls 12a and 16b (see FIGS. 2 and 3). Is sandwiched liquid-tightly, and the valve member 20 is fixed to the partition body 11. The flexible membrane portion 21 is disposed so as to intersect (substantially orthogonal) a straight line connecting the openings 12b and 16a (see FIG. 2).

  The flexible membrane portion 21 is deformed (elastically deformed) in the axial direction X (see FIG. 1) by the liquid flowing through the openings 12b and 16a when the valve member 20 is fixed to the partition body 11. A valve portion 23 that closes the openings 12b and 16a by bending deformation of the flexible membrane portion 21 is provided in the central portion of the flexible membrane portion 21 that faces the openings 12b and 16a. In the present embodiment, the valve portion 23 is a thin cylindrical portion that protrudes from the membrane surfaces on both the front and back sides of the flexible membrane portion 21, and is integrated with the flexible membrane portion 21 by a rubber-like elastic body. It is formed.

  The valve portion 23 abuts around the openings 12b and 16a and closes the openings 12b and 16a when the flexible membrane portion 21 is deformed. Since the thin-walled valve portion 23 protrudes from the membrane surfaces on both the front and back sides, it can buffer the impact when it comes into contact with the lid member 16 and the partition body 11 and is flexible even after the openings 12b and 16a are closed. The deformation | transformation of the film | membrane part 21 is accept | permitted and the transmission energy to the cover member 16 and the partition main body 11 can be relieved.

  The communication hole 21 a is formed at a position different from the portion where the straight line connecting the openings 12 b and 16 a intersects the flexible film portion 21. In the present embodiment, the communication holes 21 a are formed at four locations around the valve portion 23. The communication hole 21a is a part for allowing liquid to pass through in a state where the valve portion 23 is separated from the support body 11 and the lid member 16 (in a state where the openings 12b and 16a are opened). The communication hole 21a is set to have an opening area larger than the areas of the openings 12b and 16a so that the throttling effect does not occur.

  The flexible membrane portion 21 is provided with a plurality of columnar protrusions 24 having a protruding height larger than that of the valve body 23 and concentrically with the valve body 23 on the radially outer side of the valve body 23 and the communication hole 21a. The protrusions 24 protrude from the film surfaces on both the front and back sides of the flexible film part 21 and are integrally formed with the flexible film part 21 by a rubber-like elastic body. Since the protrusion 24 having a larger protrusion height than the valve body 23 is provided, the protrusion 24 and the valve body 23 are in contact with the lid member 16 and the partition body main body 11 in this order when the flexible film portion 21 is deformed. Since the protrusion 24 contacts the lid member 16 and the partition body 11 before the valve body 23 contacts the lid member 16 and the partition body 11, the valve member 20 contacts the lid member 16 and the partition body 11. The load change can be made smooth, and the impact can be reduced as compared with the case where the protrusion 24 is not provided.

  As shown in FIGS. 2, 3, and 4 (a), the partition body 11 has a main liquid chamber side opening 11 c formed in the outer periphery of the upper surface where the large-diameter recess 11 a is formed. As shown in FIGS. 2, 3, and 4 (b), the main liquid chamber side opening 11 c is connected to a first orifice forming groove 11 d that is recessed in the outer periphery of the partition body 11 and extends in the circumferential direction. Is done. As shown in FIGS. 4 (b) and 4 (d), the first orifice forming groove 11d is a flow path formed by axial walls 11e and 11f that are provided on the outer periphery of the partition body 11 and extend in the axial direction. Is formed and is continuously provided in the sub liquid chamber side opening 11j formed in the outer periphery of the lower surface of the partition body 11.

  The first orifice forming groove 11d is a part for forming a first orifice 44 as a throttle channel between the seal wall 6 (see FIG. 1), and the first orifice 44 is an opening on the main liquid chamber side. The main liquid chamber 41 and the first sub liquid chamber 42 communicate with each other through 11c and the sub liquid chamber side opening 11j. In the present embodiment, the first orifice 44 is tuned to a low frequency range (for example, about 5 to 15 Hz) corresponding to the shake vibration in order to attenuate the shake vibration during vehicle travel. That is, the cross-sectional area, the length, the cross-sectional circumference, etc. of the first orifice 44 are set so that the damping effect based on the resonance phenomenon of the liquid flowing through the first orifice 44 is effectively exhibited when the shake vibration is input. .

  As shown in FIGS. 1, 3, 4 (c) and 5, the partition body 11 is provided with a recess 11 k on the lower surface, and as shown in FIGS. 3 and 4 (c), the recess 11 k. The second orifice forming groove 13 and the third orifice forming groove 14 are formed in a serpentine shape on the bottom surface portion 12 of the first and second surfaces. As shown in FIG. 4 (c), one end of each of the second orifice forming groove 13 and the third orifice forming groove 14 is connected to an opening 12 b formed through the bottom surface portion 12.

  As shown in FIG. 3, the partition body 11 is brought into contact with a substantially disc-shaped lid member 17 and a cylindrical portion 17 b extending in the axial direction from the outer periphery of the lid member 17 in the recess 11 k. An annular ring body 19 is accommodated. The second diaphragm 18 is held on the lower end side of the partition body 10 by being liquid-tightly sandwiched between the lid-like member 17 and the annular body 19.

  The lid-like member 17 holds the second diaphragm 18 between the annular body 19 and the second orifice forming groove 13 and the third orifice forming groove 14 between the partition body 11 (bottom surface portion 12). These are members for forming the second orifice 45 and the third orifice 46 (see FIG. 1) as throttle channels. The lid-like member 17 has an opening 17a penetrating in the thickness direction. The opening 17a is positioned so as to be connected to the other end 13a of the second orifice forming groove 13 (see FIG. 4C) when the lid-like member 17 is accommodated in the recess 11k of the partition body 11. Formed.

  As shown in FIGS. 2 and 3, the second diaphragm 18 is formed to be thicker than the film part 18 a, which is formed along a circular film part 18 a that generates a displacement and the entire outer periphery of the film part 18 a. An outer peripheral portion 18b, and is integrally formed from a flexible rubber-like elastic film. A second sub liquid chamber 43 is provided between the lid member 17 and the second diaphragm 18 by sandwiching the second diaphragm 18 between the lid member 17 and the annular body 19 in a liquid-tight manner. The second sub liquid chamber 43 communicates with the main liquid chamber 41 through the communication hole 21a and the second orifice 45 (including the openings 12b, 16a, and 17a).

  The second orifice 45 is an orifice tuned in a higher frequency range than the first orifice 44. In the present embodiment, the second orifice 45 is tuned to a high frequency range (for example, about 15 to 50 Hz) corresponding to idle vibration in order to reduce idle vibration during idling (when the vehicle is stopped). That is, the cross-sectional area, the length, the cross-sectional circumference, etc. of the second orifice 45 are set so that the damping effect based on the resonance phenomenon of the liquid flowing through the second orifice 45 is effectively exhibited when the idle vibration is input. .

  The 3rd orifice formation groove | channel 14 is a site | part for forming the 3rd orifice 46 as a throttle flow path between the lid-shaped members 17 (refer FIG.1 and FIG.3). The third orifice forming groove 14 has an opening 11h (one end connected to an opening 12b formed through the bottom surface portion 12 and the other end passing through the outer peripheral portion of the partition body 11 in the radial direction) (FIGS. 2 and 3). And FIG. 4B). The opening 11 h is located between the axial walls 11 f and 11 g provided upright on the outer periphery of the partition body 11.

  The axial walls 11 f and 11 g extend in the axial direction with a predetermined interval, and are continuously provided with a sub liquid chamber side opening 11 i formed in a cutout on the outer periphery of the lower surface of the partition body 11. By bringing the axial walls 11f and 11g into close contact with the seal wall 6 (see FIG. 1), the third orifice 46 is connected to the second orifice 45 and the first auxiliary liquid via the opening 12b and the auxiliary liquid chamber side opening 11i. It communicates with the chamber 42.

  The third orifice 46 is an orifice tuned to a lower frequency region than the second orifice 45. That is, the third orifice so that the damping effect based on the resonance phenomenon of the liquid flowing through the third orifice 46 is more effectively exhibited in the lower frequency range than the damping effect based on the resonance phenomenon of the liquid flowing through the second orifice 45. A cross-sectional area 46, a length, a cross-sectional circumference, and the like are set.

  As described above, since the third orifice 46 is set to resonate in a lower frequency region than the second orifice 45, the resonance phenomenon of the liquid flowing through the third orifice 46 causes a lower frequency region than the second orifice 45. Can improve the damping performance.

  The second orifice 45 and the third orifice 46 are formed on one axial end face (bottom surface portion 12) of the partition body 11. By consolidating the second orifice 45 and the third orifice 46 on one axial end surface (bottom surface portion 12) of the partition body 11, the large diameter recess 11a and the small diameter recess 11b are formed on the other axial end surface of the partition body 11. The valve member 20 can be disposed in the partition body 11. Therefore, the space can be effectively used.

  In addition, the second orifice 45 and the third orifice 46 are formed by the second orifice forming groove 13 and the third orifice forming groove 14 that are recessed in one axial end face (bottom surface portion 12) of the partition body 11. Yes. Therefore, the cross-sectional area, length, and cross-sectional circumference of the second orifice 45 and the third orifice 46 can be designed relatively freely. Therefore, the degree of freedom of tuning of the second orifice 45 and the third orifice 46 can be ensured.

  A second orifice forming groove 13 and a third orifice forming groove 14 are formed on one axial end face of the partition body 11, and the second orifice 45 and the third orifice 45 between the lid body 17 accommodated in the recess 11 k are formed. An orifice 46 is formed. Since the lid-like member 17 also plays a role of holding the second diaphragm 18, the second sub liquid chamber 43 is formed by holding the second diaphragm 18 in the recess 11 k of the partition body 11. . Therefore, the addition of the third orifice 46 can be prevented from leading to the extension of the axial length of the partition body 11. As a result, the axial length of the liquid-filled vibration isolator 1 can be prevented from becoming excessive.

  The other end (second liquid chamber side opening 11 i) of the third orifice 46 communicating with the first sub liquid chamber 42 is opened on the radially outer end surface of the partition body 11. Therefore, the restriction by the second sub liquid chamber 43 and the second diaphragm 18 positioned in the axial direction of the partition body 11 can be made difficult for the third orifice 46 to receive. Further, by providing the other end of the third orifice 46 on the radially outer end face of the partition body 11, a space for providing the third orifice 46 can be secured. Can be set easily. Therefore, the degree of freedom in designing the third orifice 46 can be improved.

  Next, the liquid-filled vibration isolator 1 configured as described above will be schematically described with reference to FIG. FIG. 7 is a schematic diagram of the liquid-filled vibration isolator 1. As shown in FIG. 7, the liquid-filled vibration isolator 1 includes a main liquid chamber 41 in which a vibration isolating base 5 (see FIG. 1) forms part of a chamber wall, a first diaphragm 30, and a second diaphragm 18. A first sub liquid chamber 42 and a second sub liquid chamber 43 that respectively constitute part of the chamber wall are provided. The first orifice 44 communicates the main liquid chamber 41 and the first sub liquid chamber 42, and the second orifice 45 communicates the main liquid chamber 41 and the second sub liquid chamber 43. The third orifice 46 communicates the second orifice 45 and the first sub liquid chamber 42.

  The second orifice 45 is set so that a liquid resonance phenomenon occurs in a higher frequency range than the first orifice 44, and is configured to be opened and closed by the valve member 20 made of a rubber-like elastic film. The third orifice 46 is set so that a liquid resonance phenomenon occurs in a lower frequency region than the second orifice 45. The valve member 20 opens and closes the second orifice 107 by the operating force of the liquid flowing through the second orifice 45 and the third orifice 46.

  Next, the actuation force of the valve member 20 due to the liquid will be described with reference to FIG. FIG. 8 is a diagram (simulation result) showing the operating force of the valve member 20 by the liquid flowing through the second orifice 45 and the third orifice 46. In this simulation, excitation with a large amplitude that affects the riding comfort of the vehicle (amplitude ± 0.5 mm in this experiment) and excitation with a small amplitude that assumes idling vibration when the vehicle is stopped (amplitude ± 0 in this experiment) .1 mm) to determine the operating force.

  In the case of vibration input with small amplitude such as idle vibration when the vehicle is stopped (amplitude ± 0.1 mm), the second orifice 45 can be opened from the low frequency region to the high frequency region (O region). As a result, the liquid flows through the second orifice 45 from the low frequency range to the high frequency range. Thereby, the attenuation performance by the second orifice 45 can be obtained from the low frequency range to the high frequency range.

  On the other hand, in the case of a vibration input having a large amplitude that affects the riding comfort (amplitude ± 0.5 mm), the second orifice 45 can be closed in a low frequency range. This is presumed to be because the liquid flow of the third orifice 46 can be given to the valve member 20 in addition to the liquid flow of the second orifice 45. Since the liquid flow of the second orifice 45 and the third orifice 46 becomes the operating force of the valve member 20, the operating force of the valve member 20 can be increased as compared with the case where the third orifice 46 is not formed. As a result, since the second orifice 45 can be closed from the low frequency range, the attenuation performance in the low frequency range can be improved. As a result, it is possible to improve the ride comfort of the vehicle by suppressing vibrations in the low frequency range.

  Next, the dynamic spring constant and the damping coefficient of the liquid filled type vibration damping device will be described with reference to FIGS. FIG. 9 is a measurement result of the dynamic spring constant of the liquid-filled vibration isolator at a vibration input with a small amplitude (amplitude ± 0.1 mm), and FIG. It is a measurement result of the attenuation coefficient of a liquid enclosure type vibration isolator. 9 and 10, the embodiment is the liquid-filled vibration isolator 1, and the comparative example has the same configuration as the embodiment except that the third orifice 46 is not provided. From FIG. 9, it can be seen that there is no significant difference in the dynamic spring constant between the example and the comparative example. On the other hand, FIG. 10 shows that the attenuation coefficient in the low frequency region is higher in the example than in the comparative example. Thus, it is apparent that the embodiment having the third orifice 46 can improve the attenuation performance in the low frequency region as compared with the comparative example not having the third orifice 46.

  Next, a second embodiment will be described with reference to FIG. In the first embodiment, the second diaphragm 18 is in contact with the first liquid chamber 42, the second orifice 45 communicates the second liquid chamber 43 and the main liquid chamber 41, and the third orifice 46 is connected to the second orifice 45. The case where the first liquid chamber 42 is communicated has been described. In contrast, in the second embodiment, the second diaphragm 18 is in contact with the main liquid chamber 41, the second orifice 45 communicates the second liquid chamber 43 and the first liquid chamber 42, and the third orifice 46 is the second orifice 46. A case where the two orifice 45 and the main liquid chamber 41 are communicated will be described. In addition, about the part same as what was demonstrated in 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 11 is a schematic diagram of a liquid-filled vibration isolator 51 in the second embodiment.

  Also in the liquid filled type vibration isolator 51 in the second embodiment, as in the first embodiment, when the vibration isolating base (not shown) is elastically deformed, the main liquid chamber 41 and the first sub liquid chamber 42 are moved to each other. Causes fluid pressure fluctuations. The third orifice 46, one end of which communicates with the second orifice 45, communicates with the main fluid chamber 41, which communicates with the first orifice 44, so that the liquid of the third orifice 46 is added in addition to the liquid flow of the second orifice 45. Flow can be imparted to the valve member 20. Since the liquid flow of the second orifice 45 and the third orifice 46 becomes the operating force of the valve member 20, the operating force of the valve member 20 can be increased as compared with the case where the third orifice 46 is not formed. As a result, since the second orifice 45 can be closed from the low frequency range by the valve member 20, the attenuation performance in the low frequency range can be improved.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the number and size of the communication holes 21 a and the protrusions 24 formed in the flexible film portion 21 of the valve member 20 can be set as appropriate.

  In the above embodiment, the case where the valve portion 23 of the valve member 20 that closes the openings 12b and 16a is formed in a cylindrical shape and the valve portion 23 protrudes from the membrane surface of the flexible membrane portion 21 has been described. It is not limited to this. If the openings 12 b and 16 a can be closed by the bending deformation of the flexible membrane portion 21, the valve portion 23 does not need to protrude from the membrane surface of the flexible membrane portion 21. In this case, a part (substantially central portion) of the flexible membrane portion 21 becomes the valve portion 23 that closes the openings 12b and 16a.

  In the above embodiment, the case where the protrusions 24 are provided on both the front and back surfaces of the flexible film portion 21 of the valve member 20 has been described. However, the present invention is not limited to this, and the protrusions 24 may be omitted or the protrusions 24 may be provided. Needless to say, the flexible film portion 21 may be provided on one of the front surface and the back surface.

  In the above embodiment, the case where the main liquid chamber 41 and the first sub liquid chamber 42 are communicated with each other by the first orifice 44 has been described, but the present invention is not necessarily limited thereto. For example, the main liquid chamber 41 and the second sub liquid chamber 43 are communicated by the first orifice 44, and the two liquid chambers among the main liquid chamber 41, the first sub liquid chamber 42, and the second sub liquid chamber 43 are connected. It is naturally possible to communicate with the second orifice 45. Also in these cases, the third orifice 46 communicates with the second orifice 45 at one end and communicates the other end with the main liquid chamber 44 or one of the sub liquid chambers with which the first orifice 44 communicates. Thereby, the effect similar to 1st Embodiment is realizable.

  In the above embodiment, the case where the engine serving as the vibration source is attached to the first fixture 2 and the support-side vehicle body is attached to the second fixture 7 has been described, but the present invention is not necessarily limited thereto. It is naturally possible to attach the first fixture 2 to the support side (vehicle body) and attach the second fixture 7 to the vibration source (engine) using a bracket (not shown) as appropriate.

  In the above embodiment, the liquid-filled vibration isolators 1 and 51 that target shake vibration (for example, about 5 to 15 Hz) and idle vibration (for example, about 15 to 50 Hz) have been described, but this is an example. Of course, it is possible to provide a liquid-filled vibration isolator that can be applied to various vibrations having different frequencies.

  In the above-described embodiment, the case where the liquid-filled vibration isolator is used as an engine mount that elastically supports an automobile engine has been described. However, the present invention is not necessarily limited thereto. Of course, the liquid-filled vibration isolator can be applied to various vibration isolators such as body mounts and differential mounts.

DESCRIPTION OF SYMBOLS 1,51 Liquid enclosure type vibration isolator 2 1st fixture 5 Anti-vibration base | substrate 7 2nd fixture 10 Partition 18 2nd diaphragm (diaphragm)
20 Valve member 30 First diaphragm (diaphragm)
41 Main liquid chamber 42 First sub liquid chamber (sub liquid chamber)
43 Second sub-liquid chamber (sub-liquid chamber)
44 First orifice 45 Second orifice 46 Third orifice

Claims (4)

A first fixture attached to one of the vibration source side or the support side;
A second fixture attached to the other of the vibration source side or the support side;
An anti-vibration base interposed between the first fixture and the second fixture and made of a rubber-like elastic body;
A main liquid chamber in which the anti-vibration base constitutes a part of the chamber wall and a liquid is enclosed;
A diaphragm composed of a rubber-like elastic membrane forms a part of the chamber wall, and at least two sub liquid chambers in which liquid is enclosed;
A first orifice communicating any one of the sub liquid chambers with the main liquid chamber;
A second orifice set so as to resonate in a higher frequency range than the first orifice and communicating between any two liquid chambers of the main liquid chamber and the sub liquid chamber;
A partition that forms the second orifice and partitions any of the sub liquid chambers from the main liquid chamber;
In a liquid-filled vibration isolator comprising a valve member that is held by the partition and opens and closes the second orifice and is made of a rubber-like elastic film,
One of the second orifices communicates with the second orifice and the third orifice communicates with either the secondary liquid chamber with which the first orifice communicates or the other end with the main liquid chamber. Anti-vibration device.   The liquid-filled vibration isolator according to claim 1, wherein the third orifice is set so as to resonate in a lower frequency range than the second orifice.   The liquid-filled vibration isolator according to claim 1 or 2, wherein the second orifice and the third orifice are formed on one axial end face of the partition.   4. The liquid sealing according to claim 3, wherein the third orifice has one of the sub liquid chambers or the other end communicating with the main liquid chamber opening on a radially outer end surface of the partition body. Type vibration isolator.

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