JP2015140849A - Liquid-filled vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid-filled vibration isolator which enables improvement of a function of reducing an inner pressure of a main liquid camber without enlarging the device.SOLUTION: A liquid-filled vibration isolator includes: a storage chamber 504 which is formed in a partition member inner part 50b and communicates with a main liquid chamber 80 and an auxiliary liquid chamber 90 through first communication holes 505; and a movable plate 100 stored in the storage chamber 504. A storage chamber side wall part 506 of a partition member 50b forms a side wall of the storage chamber 504 and has opening parts 507a of second communication holes 507 allowing the storage chamber 504 to communicate with the auxiliary liquid chamber 90 in portions facing at least parts of an outer peripheral surface of the movable plate 100 in a radial direction.

Description

  The present invention relates to a liquid-filled vibration isolator used as an engine mount of a vehicle, for example.

  As a conventional liquid-filled vibration isolator, a connecting bracket connected to the supported body side, a supporting bracket connected to the support body side, a shaft connecting these two brackets and connecting both brackets at least by the elastic deformation. A rubber elastic body that is relatively displaced in the direction, a liquid chamber formed between the coupling fitting and the support fitting so that the volume changes as the rubber elastic body is deformed, and the interior of the liquid chamber includes the main liquid chamber and the auxiliary liquid. A partition member that partitions the chamber, an orifice passage that communicates the main liquid chamber and the sub liquid chamber, and a movable plate that is movably accommodated in the axial direction in a housing chamber formed inside the partition member, A known partition member is formed with a communication hole that allows the storage chamber to communicate with each of the main liquid chamber and the sub liquid chamber (for example, Patent Document 1).

  According to this prior art, at the time of normal vibration input, the vibration is absorbed and damped by the elastic deformation of the rubber elastic body and the liquid column resonance action of the liquid in the orifice passage. On the other hand, with respect to vibration having a relatively high frequency and a small amplitude, the fluid pressure fluctuation in the main liquid chamber is absorbed by the movable plate vibrating in synchronization with this vibration.

JP 2011-137477

  In the above vibration isolator, in order to improve the function of lowering the internal pressure of the main liquid chamber when inputting high-frequency and small-amplitude vibration, the storage chamber of the partition member is communicated with each of the main liquid chamber and the sub liquid chamber. It is considered effective to enlarge the opening area of the communication hole. However, in general, there are required restrictions on the radial and axial dimensions of the vibration isolator, so that the size of the apparatus is increased, and if an orifice passage is formed in the partition member, the inside of the partition member is Therefore, the orifice passage in the vicinity of the storage chamber cannot be moved, and the opening area of the communication hole of the storage chamber cannot be increased.

  An object of the present invention is to provide a liquid-filled vibration isolator capable of improving the function of reducing the internal pressure of the main liquid chamber without increasing the size of the apparatus. Is.

The liquid-filled vibration isolator according to the present invention is connected to one of the vibration generating unit and the vibration receiving unit, and is formed in a substantially cylindrical shape, and any of the vibration generating unit and the vibration receiving unit. A second mounting member connected to the other and disposed on an inner peripheral side of the first mounting member, an elastic body connecting the first mounting member and the second mounting member, and a part of the partition wall A main liquid chamber made of an elastic body, in which liquid is sealed, a sub-liquid chamber in which a part of the partition wall is made of a diaphragm and liquid is sealed, and the internal volume can be expanded and contracted according to a change in liquid pressure, A partition member provided between the main liquid chamber and the sub liquid chamber, and a housing formed inside the partition member and communicated with the main liquid chamber and the sub liquid chamber through the first communication holes, respectively. And a movable plate accommodated in the accommodation chamber, and constitutes a side wall of the accommodation chamber. The storage chamber side wall portion of the partition member is a portion radially facing at least a part of the outer peripheral surface of the movable plate, and has an opening portion of a second communication hole that communicates the storage chamber with the sub liquid chamber. It is characterized by that.
According to the liquid filled type vibration damping device of the present invention, the function of reducing the internal pressure of the main liquid chamber can be improved without increasing the size of the device.
Note that the “movable plate” refers to a plate that can move, and “movable” means that the plate moves at least in the axial direction (the entire movable plate is displaced, including vibrations, and so on). ) And elastic deformation (including vibration, the same shall apply hereinafter).

  According to the present invention, it is possible to provide a liquid filled type vibration damping device capable of improving the function of reducing the internal pressure of the main liquid chamber without increasing the size of the device.

FIG. 1A is a cross-sectional view along the axial direction showing an embodiment of a liquid-filled vibration isolator of the present invention, and FIG. 1B is a liquid-filled vibration-proof device of FIG. It is a perspective sectional view which shows an apparatus and follows an axial direction. FIG. 2 is a perspective cross-sectional view along the axial direction showing the cup-shaped intermediate member of FIG. 1 in a state in which a movable plate is accommodated. It is a perspective view which shows the cup-shaped intermediate member of FIG. 1 in the state from which the cover member was removed. It is a bottom view which shows the cup-shaped intermediate member of FIG. 1 in the state in which the movable plate was accommodated. It is a graph which shows the relationship between the frequency of an input vibration, and the dynamic spring constant of the liquid enclosure type vibration isolator of FIG.

Hereinafter, an embodiment of a liquid-filled vibration isolator (hereinafter, also simply referred to as “vibration isolator”) according to the present invention will be described with reference to the drawings.
1 to 4 show an embodiment of the vibration isolator of the present invention. The vibration isolator 1 according to the present embodiment is used as an engine mount or the like of a vehicle, and is connected between a vibration generating unit (engine or the like) and a vibration receiving unit (vehicle body or the like) and vibrates from the vibration generating unit. It functions to prevent transmission of vibration to the receiving part. FIG. 1 is a cross-sectional view showing the vibration isolator 1 along an axial direction of the vibration isolator 1 (referring to a central axis direction of an outer cylinder 10 to be described later, hereinafter simply referred to as “axial direction”). The vertical direction in FIG. 1 is the axial direction, and the direction perpendicular to the axial direction is the radial direction of the vibration isolator 1 (hereinafter simply referred to as “radial direction”).

  The vibration isolator 1 is connected to one of a vibration generating unit and a vibration receiving unit, and includes a substantially cylindrical outer cylinder 10 that constitutes a part of a first mounting member 60 described later, a vibration generating unit, and a vibration receiving unit. And a core member 20 as a second mounting member disposed on the inner peripheral side of the outer cylinder 10 and spaced from the outer cylinder 10 and coaxially with the outer cylinder 10. In the example of the drawing, the second mounting member 20 is arranged close to one axial side of the first mounting member 60 (upper side in FIG. 1, the same applies hereinafter).

  A peripheral wall 30 a of a cup-shaped elastic body 30 formed in a substantially cup shape with a rubber material or the like is fixed to the inner peripheral surface of the outer cylinder 10. One side in the axial direction of the cup-shaped elastic body 30 is open, and the other side in the axial direction of the outer cylinder 10 is the bottom wall on the other side in the axial direction of the cup-shaped elastic body 30 (the lower side in FIG. A diaphragm 30b that closes liquid tightly is configured.

  The intermediate cylinder 40 is fixed to the inner peripheral surface of the peripheral wall 30 a of the cup-shaped elastic body 30 at a position along one axial direction from the axial intermediate portion of the outer cylinder 10.

  A cup-shaped intermediate formed between the peripheral wall 30a of the cup-shaped elastic body 30 and the intermediate cylinder 40 at a position along the axially intermediate portion of the outer cylinder 10 is formed in a substantially cup shape with a resin material, an aluminum alloy or the like. The peripheral wall 50a of the member 50 is interposed. One side of the cup-shaped intermediate member 50 in the axial direction is open, and a bottom wall on the other side of the cup-shaped intermediate member 50 in the axial direction constitutes a partition member 50b described later. In the example of the figure, the cup-shaped intermediate member 50 is formed integrally with the peripheral wall 50a and the peripheral wall 50a, and includes a bottom including the bottom surface of the cup-shaped intermediate member 50 (that is, the other surface (bottom surface) in the axial direction of the partition member 50b). The material 500 and the bottom member 500 are formed separately, and have a lid member 501 that includes the floor surface of the cup-shaped intermediate member 50 (that is, the surface (upper surface) on one axial side of the partition member 50b). . The partition member 50 b includes a bottom member 500 and a lid member 501.

  The outer cylinder 10, the peripheral wall 30 a of the cup-shaped elastic body 30, the intermediate cylinder 40, and the peripheral wall 50 a of the cup-shaped intermediate member 50 constitute a first mounting member 60 as a unit. .

  The vibration isolator 1 further includes a main body elastic body (elastic body) 70 that connects the first mounting member 60 (specifically, the intermediate cylinder 40) and the second mounting member 20 on one axial side of the partition member 50b. It has. The main body elastic body 70 is provided so as to liquid-tightly close the radial gap between the first mounting member 60 and the second mounting member 20, and the outer surface of the main body elastic body 70 is on one side in the axial direction. It is formed in a substantially truncated cone shape that is convex. The bottom surface 70a of the main body elastic body 70 is convexly depressed on one side in the axial direction, and forms a substantially bell-shaped space between the partition member 50b located on the other side in the axial direction than the bottom surface 70a. In this void, an incompressible liquid such as ethylene glycol, water, or silicone oil is sealed, and a main liquid chamber 80 is formed. Since the main liquid chamber 80 has a part of the partition made of the main body elastic body 70, the main body elastic body 70 is elastically deformed according to the axial displacement of the second mounting member 20 relative to the first mounting member 60. The internal volume is expanded and contracted.

  On the other hand, the diaphragm 30b forms a space with the partition member 50b on one axial side of the diaphragm 30b. The same liquid as the main liquid chamber 80 is sealed in this space, A liquid chamber 90 is configured. The sub-liquid chamber 90 has a partition wall partly constituted by the diaphragm 30b, so that the internal volume can be expanded and contracted according to the change in the hydraulic pressure. Thus, the partition member 50b partitions both the main liquid chamber 80 and the sub liquid chamber 90 in the axial direction.

  In the example shown in FIGS. 2 to 4, an orifice passage 503 that connects the main liquid chamber 80 and the sub liquid chamber 90 is formed between the bottom member 500 and the lid member 501 inside the partition member 50 b. In the orifice passage 503, an opening 503a on one end side of the passage is formed on a surface (upper surface) on one axial side of the lid member 501, and an opening 503b on the other end side of the passage is an axis of the bottom member 500 as shown in FIG. It is formed in the surface (bottom surface) on the other side in the direction, and extends between the openings 503a and 503b in a spiral shape in the circumferential direction.

  The total length and the cross-sectional area of the orifice passage 503 are set so that the liquid column resonance of the liquid in the orifice passage 503 occurs with respect to a low-frequency large-amplitude vibration of about 5 to 20 Hz that is generated, for example, when a vehicle shakes. (Tuning) Therefore, when low-frequency large-amplitude vibration is input in the axial direction from the vibration generating unit to the apparatus, the second mounting member 20 is displaced in the axial direction with respect to the first mounting member 60, and the main liquid chamber 80 and Due to the pressure difference between the secondary liquid chamber 90, the liquid flows between the two chambers 80, 90 through the orifice passage 503. At this time, the vibration is absorbed and damped by elastic deformation of the main body elastic body 70, and is also absorbed and damped by liquid column resonance and flow path resistance of the liquid flowing in the orifice passage 503.

  Furthermore, in the partition member 50b, more specifically, a storage chamber 504 is formed between the bottom member 500 and the lid member 501 on the inner peripheral side of the orifice passage 503. The storage chambers 504 are formed on the both sides of the axial direction on the bottom member 500 and the lid member 501 (in the example of the figure, four are arranged at equal intervals in the circumferential direction), respectively, through the first communication holes 505, respectively. The main liquid chamber 80 and the sub liquid chamber 90 communicate with each other. In the example of the figure, the passage cross-sectional area of the first communication hole 505 (in the example of the figure, the passage area in the plane along the radial direction) is the entire length of the passage (in the example of the figure, the passage length along the axial direction). It is constant.

  In the storage chamber 504, a substantially disc-shaped movable plate 100 is stored. In this example, the movable plate 100 is made of an elastic material such as a rubber material, and can move minutely in the storage chamber 506 in the axial direction and the radial direction in accordance with the pressure difference between the main liquid chamber 80 and the sub liquid chamber 90. (In this example, slight movement and elastic deformation are possible). In the example shown in the figure, when no vibration is input, a part of the outer peripheral surface of the movable plate 100 abuts on the storage chamber side wall portion 506 of the partition member 50b constituting the side wall of the storage chamber 504. In some cases, as will be described later, when the movable plate 100 moves, a minute gap is temporarily formed between the outer peripheral surface of the movable plate 100 and the inner peripheral surface of the side wall of the storage chamber 504.

The inner peripheral surface of the storage chamber side wall portion 506 of the partition member 50b that constitutes the side wall of the storage chamber 504 is a portion that faces at least a part of the outer peripheral surface of the movable plate 100 in the radial direction. The second communication hole 507 communicating with the chamber 90 has an opening 507a on one end side of the passage. An opening 507b on the other end side of the passage of the second communication hole 507 is formed on the bottom surface of the partition member 50b.
Here, “at least part of the outer peripheral surface of the movable plate 100” refers to at least part of the outer peripheral surface of the movable plate 100 in the circumferential direction and the axial direction. In addition, “a portion facing at least a portion in the radial direction” refers to at least a portion in the radial projection plane. In this example, the openings 507a of the four second communication holes 507 arranged at equal intervals in the circumferential direction are arranged on the other axial side of the outer peripheral surface of the movable plate 100 (the lower side in the drawing) in the circumferential direction. It is opposed to four parts spaced at equal intervals in the radial direction.
In the illustrated example, the passage cross-sectional area of the second communication hole 507 is substantially constant over the entire length of the passage.

  In the vibration isolator 1 configured as described above, the orifice passage 503 is clogged when relatively high-frequency small-amplitude vibration (for example, vibration of about 100 to 200 Hz) is input from the vibration generating unit to the apparatus. Thus, the liquid column resonance in the orifice passage 503 and the elastic deformation of the main body elastic body 70 do not occur. However, at this time, the vibration isolator 1 causes the internal pressure of the main liquid chamber 80 to escape by the internal pressure of the main liquid chamber 80 escaping to the sub liquid chamber 90 when the movable plate 100 moves slightly (slight movement and elastic deformation). The vibration isolation effect is demonstrated by lowering the value. The function of lowering the internal pressure by the movable plate 100 at this time increases as the total opening area of the storage chamber 504 to the main liquid chamber 80 or the sub liquid chamber 90 increases. In this example, in addition to the opening 505a of the first communication hole 505 facing the movable plate 100 in the axial direction, the partition member 50b has an opening 507a of the second communication hole 507 facing the movable plate 100 in the radial direction. Since the total opening area to the sub liquid chamber 90 is larger than the case where only the opening 505a of the first communication hole 505 is provided, there is an opening 507a of the second communication hole 507. Without the need for an increase in size, the function of reducing the pressure in the main liquid chamber by the movable plate 100 and thus the vibration isolating function of the vibration isolator 1 can be improved.

  Note that the function of reducing the internal pressure by the movable plate 100 is effective not only when high-frequency small amplitude vibration is input but also when excessive vibration is input. That is, when the excessive vibration is input, the function of reducing the internal pressure of the main liquid chamber 80 by the movable plate 100 is exhibited, so that the internal pressure varies between when a positive pressure is applied to the main liquid chamber 80 and when a negative pressure is applied. Therefore, when the cavitation occurs, it is possible to reduce the noise generated when the bubbles disappear.

  Further, in this example, the movable plate 100 is configured to be movable and elastically deformable in the axial direction and slightly in the radial direction in the storage chamber 504. Therefore, when the vibration is input, the movable plate 100 and the outer peripheral surface of the movable plate 100 are stored. A minute gap is temporarily generated between the inner wall of the chamber 504 (that is, the storage chamber side wall 506 of the partition member 50b). This gap, together with the first communication hole 505 and the second communication hole 507, forms a second orifice passage that communicates the main liquid chamber 80 and the sub liquid chamber 90. At this time, due to the pressure difference between the main liquid chamber 80 and the sub liquid chamber 90, the liquid flows between the two chambers 80, 90 through the second orifice passage, and vibration is generated in the liquid in the second orifice passage. It is absorbed and attenuated by the liquid column resonance. The resonance frequency of the liquid column resonance in the second orifice passage increases as the total opening area of the storage chamber 504 to the main liquid chamber 80 or the sub liquid chamber 90 increases. In this example, since the total opening area to the sub liquid chamber 90 is larger than the case where only the opening 505a of the first communication hole 505 is provided, the amount of the opening 507a of the second communication hole 507 is increased. In addition to the improvement of the internal pressure reduction function, the resonance frequency in the high frequency region of the apparatus can be tuned higher. This is particularly advantageous when there is a need to increase the resonance frequency in the high frequency region without increasing the size of the device.

  In order to confirm the effect of increasing the resonance frequency of the vibration isolator according to the present embodiment, the anti-vibration devices of the example and the comparative example are respectively prototyped, and the relationship between the frequency of the input vibration and the dynamic spring constant of the device is tested. It was investigated by. The results are shown in the graph of FIG. As shown in the example of FIG. 1, the vibration isolator of the embodiment includes a second communication hole 507 in which the storage chamber side wall portion 506 of the partition member 50 b is a portion that faces a part of the outer peripheral surface of the movable plate 100 in the radial direction. The opening 507a is provided. The vibration isolator of the comparative example does not have the second communication hole 507 that allows the storage chamber 504 to communicate with the sub liquid chamber 90, and therefore the storage chamber side wall portion 506 of the partition member 50 b is the opening of the second communication hole 507. It differs from the vibration isolator of an Example by the point which does not have 507a. For each vibration isolator, the dynamic spring constant of the vibration isolator 1 obtained when the frequency of the input vibration was changed under the same amplitude (0.05 mm) was examined. In the graph of FIG. 5, the horizontal axis indicates the frequency (Hz) of the input vibration, and the vertical axis indicates the dynamic spring constant (N / mm) of the device. The waveforms A and B are the vibration isolation of the comparative example and the example, respectively. It represents the test result of the device. As can be seen from the graph of FIG. 5, the peak of the waveform B is displaced to the higher frequency side than the peak of the waveform A, that is, the vibration isolator of the embodiment is compared with the vibration isolator of the comparative example. It was confirmed that the resonance frequency could be increased.

  As described above, according to the present embodiment, the function of reducing the main liquid chamber pressure can be improved without increasing the size of the apparatus, and hence the vibration isolation function can be improved and the abnormal noise of cavitation can be reduced. .

  In addition, according to the present embodiment, the movable plate 100 is configured to be movable and elastically deformable in the accommodation chamber 504 so that the second orifice passage is temporarily formed at the time of vibration input. The resonance frequency can be increased.

  In addition, the structure of the vibration isolator 1 is not restricted to what was mentioned above, A various modification is possible. For example, the movable plate 100 that can improve the internal pressure reduction function is not limited to one that can move and elastically deform, and as long as at least one of movement and elastic deformation at least in the axial direction is possible in the storage chamber 504, for example, It is made of a movable plate made of a hard material such as a resin material that cannot be elastically deformed but at least movable, or an elastic material such as a rubber material that cannot be moved because the peripheral edge is fixed in the storage chamber 504 but can be elastically deformed. A movable plate or the like may be used. In order to realize the internal pressure reduction function, it is sufficient that the movable plate 100 is movable, and it is not necessary to be able to form the second orifice passage at the time of vibration input.

  Further, as the movable plate 100 that can form the second orifice passage at the time of vibration input, other than the movable plate that can move and elastically deform, for example, the movable plate 100 that is not elastically deformable but can move in the axial direction and a slight radial direction. A board etc. may be sufficient.

  As long as the first mounting member 60 includes at least the outer cylinder 10, at least one of the peripheral wall 30 a of the cup-shaped elastic body 30, the intermediate cylinder 40, and the peripheral wall 50 a of the cup-shaped intermediate member 50 may be omitted. .

1: liquid filled vibration isolator, 10: outer cylinder (first mounting member), 20: core member (second mounting member), 30: cup-shaped elastic body, 30a: peripheral wall (first mounting member), 30b: Diaphragm, 40: intermediate cylinder (first mounting member), 50: cup-shaped intermediate member, 50a: peripheral wall (first mounting member), 50b: partition member, 60: first mounting member, 70: elastic body (elastic body) ), 70a: bottom surface, 80: main liquid chamber, 90: sub liquid chamber, 100: movable plate, 500: bottom member (partition member), 501: lid member (partition member), 503: orifice passage, 503a, 503b: 505: first communication hole, 505a: first communication hole opening, 506: storage chamber side wall, 507: second communication hole, 507a, 507b: second communication hole Opening Part

Claims (1)

A first mounting member connected to either one of the vibration generating portion and the vibration receiving portion and formed in a substantially cylindrical shape;
A second mounting member connected to the other of the vibration generating unit and the vibration receiving unit and disposed on the inner peripheral side of the first mounting member;
An elastic body connecting the first mounting member and the second mounting member;
A main liquid chamber in which a part of the partition wall is made of the elastic body and the liquid is sealed;
A sub-liquid chamber in which a part of the partition wall is made of a diaphragm and a liquid is enclosed, and the internal volume can be expanded and contracted according to a change in the hydraulic pressure,
A partition member provided between the main liquid chamber and the sub liquid chamber;
A storage chamber formed inside the partition member and communicated with the main liquid chamber and the sub liquid chamber through a first communication hole;
A movable plate housed in the housing chamber;
With
The storage chamber side wall portion of the partition member constituting the side wall of the storage chamber is a portion that faces at least a part of the outer peripheral surface of the movable plate in the radial direction, and communicates the storage chamber with the sub liquid chamber. A liquid-filled vibration isolator having two communication hole openings.