JPH11125305A - Arm member with vibration control bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration control performance against high frequency vibration while securing static spring stiffness or spring stiffness against low frequency vibration. SOLUTION: In this arm member 36, a main liquid chamber 38 is formed in a vibration control bush 16 mounted in the arm member 36 and pressure fluctuation is generated by an actuator 52 so as to control the internal pressure of the main liquid chamber 38, thereby, for exhibiting an active vibration control effect, an actuator using a magnetostrictive element or an electrostrictive element is employed as the actuator 52, and also the actuator 52 is mounted in an arm member 12. Hereby, an arrangement space for the large actuator 52 can be efficiently secured and vibration control effect against high frequency vibration based on the pressure control of the main liquid chamber 38 can be improved. As a result, static spring stiffness or spring stiffness against low frequency vibration can be simultaneously secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arm member mounted between two members and connecting the two members in a vibration-proof manner. The present invention relates to an attached arm member. More specifically, the present invention relates to an arm member having a fluid-filled type vibration-isolating bush capable of adjusting the vibration-isolating characteristics of the vibration-isolating bush by actively controlling the pressure of a liquid chamber formed in the vibration-isolating bush. Things.

[0002]

2. Description of the Related Art Conventionally, as an arm member interposed between members constituting a vibration transmission system and connecting these members with vibration isolation, Japanese Utility Model Publication No. 47-13925 and Japanese Patent Publication No.
As described in Japanese Patent No. 637 or the like, a structure in which a rubber bush is attached to at least one attachment portion of an arm member is known. Such an arm member with an anti-vibration bush is suitably employed as, for example, a suspension arm, a suspension member, a differential mount member, a subframe, and the like, in addition to a suspension rod of an automobile. In such an arm member, an incompressible fluid is sealed in a rubber bush as described in JP-B-6-29637 in order to achieve the required vibration isolation characteristics. A fluid-filled anti-vibration bush or the like, which forms a liquid chamber and uses a fluid action such as a resonance action of a fluid, is employed.

However, in recent years, the required vibration damping performance has been advanced, so that it is sometimes difficult to achieve sufficient vibration damping performance only by utilizing the passive fluid flow action at the time of vibration input. there were. In particular, arm members used in suspension systems of automobiles require high stiffness and high damping in low-frequency vibration regions in order to ensure the steering stability of the vehicle. Even in the region, it was extremely difficult to ensure sufficient anti-vibration performance by exhibiting a sufficiently low dynamic spring characteristic.

In Japanese Patent No. 2510915, etc., a part of a wall portion of a liquid chamber is constituted by a diaphragm, and the diaphragm is vibrated by electromagnetic driving means such as a voice coil type or a moving coil type. An internal pressure control type fluid-filled cylindrical mount has been proposed in which the internal pressure of the liquid chamber can be actively controlled in accordance with the input vibration to adjust the vibration isolation characteristics. It is also conceivable to apply the present invention to a vibration isolating bush of a member. However, the anti-vibration bush of the arm member is generally a small one that can be assembled into a mounting hole such as an arm eye formed at the end of the arm member, and it is necessary to provide a large-sized electromagnetic drive means such as a permanent magnet or a coil. However, it was extremely difficult. In particular, since a large load during traveling is input to the arm members constituting the suspension system of the automobile, electromagnetic drive means of a general size require:
There is also a problem that it is difficult to apply a vibrating force to the diaphragm so that effective internal pressure control can be performed, and it is difficult to achieve a desired vibration damping performance.

In such an internal pressure control type fluid-filled cylindrical mount, an electrostrictive element capable of generating a larger driving force in place of the electromagnetic driving means in order to apply a large excitation force to the diaphragm. It is also conceivable to use a magnetostrictive element. However, the electrostrictive element and the magnetostrictive element have a problem that it is difficult to generate a sufficiently large internal pressure change amount with respect to the liquid chamber because the output stroke is small, and thus, it is not always effective. Also, in order to secure the output stroke, it is necessary to use a long distortion element,
Eventually, there is a problem that the size becomes large and it is difficult to apply the anti-vibration bush to the arm member.

[0006]

Here, the present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to secure high-rigidity characteristics in a low-frequency vibration region while maintaining high-frequency characteristics. Another object of the present invention is to provide an arm member with a vibration-proof bush having a novel structure in which an excellent vibration-insulating effect is exhibited based on the control of the internal pressure of the liquid chamber formed in the vibration-proof bush in the vibration region.

Further, according to the present invention, an actuator capable of exerting a large excitation force on a diaphragm constituting a wall portion of a liquid chamber formed in a vibration-proof bush can be mounted with excellent space efficiency. It is also an object of the present invention to provide an arm member with a vibration-isolating bush having a novel structure in which an effective vibration-damping effect is advantageously exerted by effective internal pressure control in a room.

[0008]

In order to solve such a problem, a feature of the invention according to claim 1 is that a shaft member and an outer cylinder member are provided on a main body with respect to an arm member connecting two members. An arm member with an anti-vibration bush is assembled with a vibration-isolating bush connected by a rubber elastic body, and the arm member is attached to a member to be connected via the vibration-isolating bush. for,
A part of the wall is formed of the main rubber elastic body to form a main liquid chamber in which an incompressible fluid is sealed, and another part of the wall of the main liquid chamber is formed of the outer cylinder. An actuator using a strain element deformable by a change in an electric field or a magnetic field is mounted on the arm member, and the diaphragm is vibrated by the actuator. Thus, the internal pressure of the main liquid chamber is controlled.

The anti-vibration bush only needs to be mounted on at least one mounting portion for at least one of the members connected by the arm member. In addition, as a mounting mode of the actuator to the arm member, in addition to mounting the actuator by housing the actuator inside the arm member,
An actuator may be mounted on the outer surface of the arm member. Furthermore, as the arm member, any one formed of metal, resin, or the like can be adopted. In addition to the longitudinal rod shape, an L-shaped arm or an A-shaped arm for an automobile, or a subframe for an automobile or the like can be used. In addition, various shapes can be adopted. Further, in order to displaceably support the vibration plate, an elastic support structure using, for example, a rubber elastic body or a metal plate spring is advantageously employed.

[0010] In the arm member with the vibration isolating bush having the structure according to the first aspect of the present invention, the actuator for vibrating the diaphragm of the main liquid chamber is mounted on the arm member. Therefore, even if the size of the anti-vibration bush itself is small, an anti-vibration bush of an internal pressure control type that can actively control the anti-vibration characteristics can be advantageously realized. Moreover, since an actuator using a strain element is employed as the actuator, a large excitation force can be applied to the diaphragm, and effective internal pressure control can be realized even when the input load is large. Excellent vibration damping effect is exhibited. In addition, since the actuator can be mounted on the arm and the installation space can be advantageously secured, the size of the strain element used can be lengthened, thereby setting a large output stroke of the actuator. As a result, more effective internal pressure control is realized, and a more excellent anti-vibration effect is exhibited.

Particularly, the space for disposing the actuator is
By forming it at a position extending from the mounting hole of the vibration isolating bush into the inside of the arm member, a high degree of space efficiency is realized, and there is no problem of damping the actuator to another member. At that time, the arm member can be used as a case member (housing) for the actuator.

Further, in the arm member with the vibration isolating bush having such a structure, since the internal pressure of the main liquid chamber is controlled, the excellent vibration isolating effect particularly against the high frequency vibration is advantageously exerted. It is possible to set the static spring rigidity of the anti-vibration bush itself high and to set a large damping characteristic against low-frequency vibration while sufficiently securing the anti-vibration performance, and therefore, for example, in an arm member of a suspension system of an automobile. This makes it possible to achieve a high level of both steering stability and ride comfort.

The invention according to claim 2 has been made in order to solve the above-mentioned problem, and the feature of the invention is that an arm member for connecting two members is provided. An arm with a vibration-isolating bush in which a vibration-isolating bush in which a shaft member and an outer tubular member are connected by a rubber elastic body is assembled, and the arm member is attached to a member to be connected via the vibration-isolating bush. In the member, a part of a wall portion is formed of the main rubber elastic body with respect to the vibration isolating bush to form a main liquid chamber in which an incompressible fluid is sealed, while a part of the wall portion is formed. It has a pressurizing chamber composed of a diaphragm supported displaceably and in which an incompressible fluid is sealed, and has an actuator using a strain element that is deformed by a change in an electric field or a magnetic field. Diaphragm A pressure generating device for generating a pressure change in the pressurizing chamber by vibrating; and a fluid conduit connecting the pressurizing chamber of the pressure generating device to the main liquid chamber of the vibration isolating bush. The internal pressure of the main liquid chamber is controlled by the vibration of the vibration plate by the actuator in the generator.

As in the case of the first aspect of the present invention, the vibration-isolating bush only needs to be mounted on at least one attachment portion of the arm member. Materials and various shapes such as an automobile suspension arm can be adopted. Further, the actuator may be fixedly attached to the arm member inside or on the outer surface of the arm member, or may be attached to a member different from the arm member. Furthermore,
The fluid pipe may be a rigid pipe or a flexible pipe. In addition to a metal pipe, a rubber pipe or a resin pipe may be used. Is desirable. In order to displaceably support the diaphragm, an elastic support structure using, for example, a rubber elastic body or a metal plate spring is advantageously employed.

In the arm member with the vibration isolating bush having the structure according to the second aspect of the present invention, the actuator which exerts a pressure change on the main liquid chamber is formed separately from the vibration isolating bush. Because it can be installed in another suitable empty space away from the mounting part of the anti-vibration bush, even if the size of the anti-vibration bush itself is small, internal pressure control that can actively control the anti-vibration characteristics An anti-vibration bushing of the type is advantageously realized. In addition, as in the first aspect of the invention, since an actuator using a long strain element can be employed, effective internal pressure control is applied to the main liquid chamber even when the input load is large. It is possible to achieve excellent vibration damping effect.

In particular, in the arm member with the vibration isolating bush having the structure according to the second aspect of the present invention,
By appropriately tuning the length and cross-sectional area of the flow path in the fluid pipeline, the resonance frequency of the incompressible fluid flowing through the fluid pipeline can be made to correspond to the vibration frequency to be damped. ,Thereby,
By utilizing the resonance effect of the fluid flowing through the fluid conduit, the pressure transmission efficiency from the pressurized chamber to the main liquid chamber is improved,
Thus, it is possible to further improve the internal pressure control effect of the main liquid chamber and further improve the vibration isolation performance.

In the arm member with a vibration isolating bush having the structure according to any one of the first and second aspects of the present invention, the vibration isolating bush is independent of the main liquid chamber by a vibration input. An orifice passage which forms a sub-liquid chamber in which an incompressible fluid is sealed and in which a relative pressure change is generated between the main liquid chamber and the main liquid chamber and the sub-liquid chamber. Can be advantageously adopted.

In the arm member with the vibration isolating bush having such a structure, by appropriately adjusting the passage cross-sectional area and the passage length of the orifice passage, it is possible to make use of the resonance action of the fluid which can flow through the orifice passage. In order to improve the internal pressure control effect of the main liquid chamber, or to improve the vibration isolation performance against input vibration in a frequency range (for example, a low frequency range) where the vibration control effect by the internal pressure control of the main liquid chamber is not effectively exerted. It becomes possible. The auxiliary liquid chamber has a part of the wall made of a rubber elastic body and is located on the opposite side of the main liquid chamber with the shaft member interposed therebetween. In addition to the pressure-receiving chamber structure in which the internal pressure fluctuation is positively generated, a part of the wall is made of a flexible membrane which is easily deformed, and the volume change is easily allowed, so that the pressure fluctuation is caused. And the like having an equilibrium chamber structure that absorbs the water can be adopted.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a vehicle suspension arm 10 according to an embodiment of the present invention. The suspension arm 10 has a structure in which a first rubber bush 14 and a second rubber bush 16 as vibration isolating bushes are attached to both ends in the axial direction of a rod portion 12 having a long rod shape extending linearly. Have. Although not explicitly shown in the drawings, one end of the suspension arm 10 is attached to one of the vehicle body side and the wheel side via the first rubber bush 14, while the other end is Is attached to one of the vehicle body side and the wheel side via the second rubber bush 16 so that the wheel side member is vibration-proof connected to the vehicle body side member. In this mounted state, the main vibration to be damped is input to the suspension arm 10 in the axial direction of the rod portion 12.

More specifically, the first rubber bush 14
The first inner cylinder fitting 18 having a small-diameter cylindrical shape and the first outer cylinder fitting 20 having a thin large-diameter cylindrical shape are coaxially arranged apart from each other in the radial direction. Inner and outer cylinder fittings 1
The first and second rubber bodies 8 and 20 are elastically connected by a first rubber elastic body 21. In other words, the first main rubber elastic body 21 has a thick cylindrical shape, and the first inner cylindrical metal fitting 1 is provided on the inner peripheral surface of the first main rubber elastic body 21.
8, the first rubber bush 14 is formed as an integrally vulcanized molded product in which the first outer cylinder fitting 20 is vulcanized and bonded to the outer peripheral surface.

Further, the first rubber bush 14 is
After the first outer cylindrical member 20 is reduced in diameter as necessary and a pre-compression is applied to the first main rubber elastic body 21, the first arm eye 22 made of a metal having a thick large-diameter cylindrical shape is formed. , And the first outer cylinder fitting 20 is internally fitted and fixed to the first arm eye 22. Further, a first rod tube fitting 24 having a linear cylindrical shape is welded and fixed to the outer peripheral surface of the first arm eye 22. The shaft is projected outward from the arm eye 22 with the axis orthogonal to the center axis of the arm eye 22.

On the other hand, the second rubber bush 16 comprises a small-diameter cylindrical inner cylinder 26 and a thin, large-diameter cylindrical outer cylinder 28 which are coaxially spaced apart in the radial direction. And the second inner and outer tube fittings 26, 28
Are elastically connected by a second main rubber elastic body 30. In short, the second main rubber elastic body 30 has a thick cylindrical shape, and the second inner cylindrical fitting 26 and the second outer cylindrical fitting 28 are formed on the inner and outer peripheral surfaces thereof.
A second rubber bush 16 is formed as an integrally vulcanized molded product which is respectively vulcanized and bonded. Further, in such an integrally vulcanized molded product, with respect to the second outer metal fitting 28,
A substantially circular opening window 32 is formed at one location on the periphery, and a concave pocket portion 34 is formed on the outer peripheral surface of the second rubber elastic body 30. The pocket portion 34 is opened through the opening window 32 on the outer peripheral surface of the second external metal fitting 28.

Further, the second rubber bush 16
If necessary, after the second outer metal fitting 28 is reduced in diameter and pre-compressed to the second main rubber elastic body 30, a second arm eye 36 made of metal having a thick large-diameter cylindrical shape is formed. , And the second outer cylinder fitting 28 is internally fitted and fixed to the second arm eye 36. Thereby,
The opening window 32 of the second outer tube fitting 28 is the second arm eye 3
6, a main liquid chamber 38 in which an incompressible fluid is sealed is formed in the pocket portion 34. In addition, as the non-compressible fluid, water, alkylene glycol, polyalkylene glycol, silicone oil and the like can be suitably used.
The following are advantageously used:

The second arm eye 36 covers a portion of the wall of the main liquid chamber 38 by covering the opening window 32 of the second external metal fitting 28 and facing the outer peripheral surface. A cylindrical opening 40 having a cylindrical shape that protrudes and opens is provided. Further, a vibration plate 42 is provided in the cylindrical opening 40, and is elastically connected to the cylindrical opening 40 by a connecting rubber elastic body 44. The diaphragm 42 is formed of a rigid material such as metal or resin, and has a thick disk shape. Also, the connecting rubber elastic body 44
Has a cylindrical shape, the diaphragm 42 is vulcanized and bonded to the inner peripheral surface, and the thin cylindrical metal sleeve 46 is vulcanized and bonded to the inner peripheral surface. In short, the connecting rubber elastic body 44 is formed as an integrally vulcanized molded product having the diaphragm 42 and the metal sleeve 46.

Then, in the integrally vulcanized molded product of the connecting rubber elastic body 44, the metal sleeve 46 is reduced in diameter as necessary, and the connecting rubber elastic body 44 is pre-compressed. The cylindrical opening 40 of the second arm eye 36
Is press-fitted into the cylindrical opening 40 so as to be fitted and fixed in a fluid-tight manner. Thereby, the diaphragm 42
Is connected to the second arm eye 36 by the connecting rubber elastic body 4.
4, it is elastically connected and supported via the diaphragm 4, and a part of the wall of the main liquid chamber 38 is constituted by the vibration plate 42.

In short, the main liquid chamber 38 has a part of its wall portion constituted by the second main rubber elastic body 30 and the vibration plate 42, and the second main rubber elastic body 30 at the time of vibration input. The change in internal pressure is caused based on the elastic deformation. Conversely, by controlling the internal pressure of the main liquid chamber 38, it is possible to adjust the vibration-proof characteristics of the second rubber bush 16 and thus the suspension arm 10. The sealing of the fluid into the main liquid chamber 38 is performed, for example, by pressing the metal sleeve 46 into the second arm eye 36 and assembling the vibration plate 42, and then attaching the second outer eye to the second arm eye 36 in the fluid. This can be advantageously performed by press-fitting the cylindrical metal fitting 28 and assembling the second rubber bush 16.

Further, a second rod-shaped metal fitting 48 having a long cylindrical shape is externally fitted to the cylindrical opening 40 of the second arm eye 36 at an opening at one end thereof, and is welded as necessary. Fixed. A hard lid 50 having a disc shape is press-fitted and fixed to the other end side opening of the second rod cylinder fitting 48.
As a result, the openings on both axial sides of the second rod cylinder fitting 48 are covered with the diaphragm 42 and the cover 50.

An actuator 52 for driving the vibration plate 42 to vibrate is accommodated inside the second rod tube fitting 48, and is located on the opposite side of the main liquid chamber 38 with the vibration plate 42 interposed therebetween. It is arranged. This actuator 5
2 is provided with a magnetostrictive element 54 having a circular block shape or a rod shape, and the magnetostrictive element 54 is disposed on the central axis in the second rod cylinder 48.

Hard end members 56 and 58 each having a substantially disk shape are superposed and fixed on both end surfaces in the axial direction of the magnetostrictive element 54.
8 with respect to the second rod cylinder fitting 48 via the ring-shaped support member 60 in a state where small axial displacement of the second rod cylinder fitting 48 is allowed, and in the direction perpendicular to the axis. It is mounted in a state where displacement is suppressed as much as possible. The one end member 56 is overlaid on the diaphragm 42 and fixed with bolts. Further, the other end member 58 is superimposed on the lid 50 and is attached by bonding or the like as necessary. In particular, in the present embodiment, the coil spring 6 is disposed between the end member 56 bolted to the diaphragm 42 and the opening end surface of the cylindrical opening 40.
2, and a biasing force is applied to the end member 56 in a direction away from the cylindrical opening 40. The biasing force of the coil spring 62 is applied from the magnetostrictive element 54 to the other end member 58, and the end member 58 is pressed and fixed to the lid 50, so that the magnetostrictive element 54 on the side opposite to the diaphragm 42 is fixed. The end is fixedly supported by the second rod tube fitting 48. Moreover, the compression force in the axial direction (output stroke direction) is applied to the magnetostrictive element 54 as a preload by the urging force of the coil spring 62. Note that the urging force of the coil spring 62 is sufficient to fix the end member 58 to the lid 50, can exert an effective preload on the magnetostrictive element 54, and is generated by axial magnetostriction of the magnetostrictive element 54. It is set so that it can be smoothly expanded and contracted.

A bobbin 6 is provided outside the magnetostrictive element 54.
A coil 68 wound around 6 is provided, and power is supplied through a lead wire (not shown). The bobbin 66 around which the coil 68 is wound is formed of a nonmagnetic material such as resin or aluminum, and is extrapolated to the outer peripheral surface of the magnetostrictive element 54 with a predetermined gap. The bobbin 66 is fixed at one end in the axial direction to an end member 58 fixed to the lid 50, while the bobbin 66 is fixed to an end member 56 fixed to the other axial end of the magnetostrictive element 54. The bobbin 66 and the coil 6 are spaced apart from each other by a predetermined distance.
8 prevents the expansion and contraction of the magnetostrictive element 54 in the axial direction from being hindered.

In the actuator 52 including the magnetostrictive element 54 and the coil 68 as described above, the magnetic field generated by energizing the coil 68 generates a magnetic field.
4 and the magnetostrictive element 54
Is deformed (expansion and contraction in the axial direction). When the deformation of the magnetostrictive element 54 is applied to the vibration plate 42, the vibration plate 42 moves in and out of the main liquid chamber 38 (the axial direction of the cylindrical opening 40).
It is designed to be displaced. In addition,
Here, as the magnetostrictive element 54, it is possible to use a general magnetic material such as nickel and an alfero alloy, but in particular, a magnetic material containing a rare earth element such as terbium (Tb), and more preferably terbium (Tb) And a composition containing dysprosium (Dy) and iron (Fe),
A giant magnetostrictive element in which the displacement of a crystal caused by magnetostriction reaches a maximum of 2000 ppm is preferably employed.

Further, the second rod tube fitting 48 in which such an actuator 52 is built in is provided with an axial end opposite to the second arm eye 36.
A first rod tube fitting 24 fixed to the first arm eye 22 is externally inserted and welded as necessary to be externally fitted and fixed. Thereby, the first rod cylinder 24 and the second rod cylinder 48 are connected and fixed on the same axis in the axial direction, and as a whole one rod portion 1 is formed.
The first and second arm eyes 22,
The first rubber bush 14 is incorporated into the first arm eye 22, and the second rubber bush 16 is incorporated into the second arm eye 36. Have been.

In the suspension arm 10 according to the present embodiment having the above-described structure, an alternating current is applied to the coil 68, and the magnetostrictive element 54 is caused to expand and contract in the axial direction by the magnetic action of the coil 68. The vibrating plate 42 forming the wall of the main liquid chamber 38 formed in the second rubber bush 16 is vibrated in a direction to expand and contract the volume of the main liquid chamber 38. Therefore, the internal pressure of the main liquid chamber 38 can be controlled by controlling the current supplied to the coil 68 to vibrate the vibration plate 42 at an appropriate cycle and stroke. The vibration isolating characteristics of the bush 16 and thus the suspension arm 10 are appropriately adjusted according to the vibration to be damped.
It can be changed and adjusted.

Specifically, for example, when high-frequency vibration causing road noise or muffled sound is input due to road surface unevenness or suspension member resonance, the diaphragm 42 is caused to vibrate in an opposite phase to the input vibration. The second rubber bush 1
In FIG. 6, the vibration can be offset and the vibration transmissibility can be reduced. In particular, in the suspension arm 10 as described above, effective vibration damping performance against high frequency vibration is achieved based on the active vibration damping effect by adjusting the pressure of the main liquid chamber 38. For example, by appropriately setting the material and shape of the main rubber elastic bodies 21 and 30 with respect to the first and second rubber bushes 14 and 16 while securing the vibration isolating performance, the static spring constant can be improved. In addition, the dynamic spring constant for low-frequency vibration can be set to be large, thereby making it possible to realize a high degree of steering stability while securing excellent vehicle riding comfort.

Moreover, the suspension arm 10
Since the actuator 52 for vibrating the vibration plate 42 is assembled in a state where the actuator 52 is completely housed in the rod portion 12, even when the small first rubber bush 16 is employed, the The arrangement space of 52 can be advantageously secured, and the vibration-proof effect by controlling the internal pressure of the main liquid chamber 38 can be advantageously used. In particular, by utilizing the space in the rod portion 12, it is possible to secure a large space for disposing the actuator 52 without increasing the size of the entire suspension arm 10, so that the magnetostrictive element 54
Set the dimension in the output stroke direction of
A large output stroke can be obtained, and therefore, the deformation amount is sufficiently secured while ensuring the advantages of the magnetostrictive element such as excellent response speed, easy control, and easy acquisition of a large driving force. To effectively reduce or eliminate the disadvantage of the magnetostrictive element having a small (output stroke) due to the characteristic of the magnetostrictive element, and to effectively and stably obtain an excellent anti-vibration effect based on the internal pressure control of the main liquid chamber 38. Can be done.

Next, FIG. 2 shows a suspension arm 70 as a second embodiment of the present invention.
The suspension arm 70 has a rubber bush 74 as an anti-vibration bush attached to one part of an arm member 72. Through this rubber bush 74, the arm member 72 is connected to one member (not shown) to be connected. It can be attached. The rubber bush 74 is provided with a main liquid chamber 76 in which an incompressible fluid is sealed, and the internal pressure of the main liquid chamber 76
The vibration control of the rubber bush 74 and the suspension arm 70 is adjusted and controlled based on the pressure control of the main liquid chamber 76. It has become.
It should be noted that a portion of the arm member 72 to be attached to the other member to be connected is not shown.

More specifically, the arm member 72 has a rod portion 80 made of a metal cylinder, and an arm eye 82 made of a metal large-diameter cylinder is attached to one end of the rod portion 80. However, they are fixed by welding with their central axes orthogonal to each other. Then, for this arm eye 82,
A rubber bush 74 is assembled. When the suspension arm 70 is mounted on the vehicle, the main vibration to be damped is input in the axial direction of the rod portion 80.

The rubber bush 74, like the second rubber bush 16 in the first embodiment, has a small-diameter cylindrical inner cylindrical fitting 84 which is coaxially spaced apart from each other in the radial direction and has a large wall thickness. It has an outer cylindrical metal fitting 86 having a diameter cylindrical shape, and the inner and outer cylindrical metal fittings 84 and 86 are attached to the main rubber elastic body 8.
8, the structure is elastically connected. The main rubber elastic body 88 is formed with a pocket 90 that opens on the outer peripheral surface.
An outer peripheral surface is opened through an opening window 92 formed in the outer tube fitting 86.

Then, if necessary, the main rubber elastic body 88
After pre-compression is applied to the arm eye 82, the rubber bush 74 is press-fitted into the arm eye 82, and the outer tube 86 is fitted and fixed to the arm eye 82 to be assembled. Here, the pocket portion 90 is located on the opposite side of the arm eye 82 in the radial direction from the connecting portion of the rod portion 80, and the opening window 92 is covered with the arm eye 82 in a fluid-tight manner, so that the incompressible fluid is Is formed in the main liquid chamber 76. The same fluid as the main liquid chamber of the first embodiment can be used as the sealed fluid.

In short, the main liquid chamber 76 has a part of the wall formed of the main rubber elastic body 88, and an internal pressure change is generated based on the elastic deformation of the main rubber elastic body 88 at the time of vibration input. Conversely, by controlling the internal pressure of the main liquid chamber 76,
It is possible to adjust the vibration isolating characteristics of the rubber bush 74 and thus the suspension arm 70.

Further, the arm eye 82 is provided with the outer tube fitting 8.
A port portion 95 that protrudes outward is formed at a portion that covers the opening window 92 of FIG. 6, and the incompressible fluid can be supplied to and discharged from the main liquid chamber 76 through the port portion 95. You can do it. That is, the port 95
It is possible to control the internal pressure of the main liquid chamber 76 by the supply and discharge of the incompressible fluid through.

On the other hand, the pressure generating device 78 is provided with a metal case cylinder 96 having a longitudinal cylindrical shape, and has a bottomed cylindrical shape at one opening of the case cylinder 96. One lid 98 is press-fitted and fixed at its opening side, and a second lid 100 having a disc shape is press-fitted and fixed to the other opening of the case cylinder 96. . The case cylinder 96 and the first and second lids 98 and 100 constitute a hollow cylindrical device housing 101.

A diaphragm 102 is provided at the opening of the first lid 98, and is elastically connected to the opening of the first lid 98 by the connecting rubber elastic body 104. Have been. The diaphragm 102 has a thick disk shape, like the diaphragm of the first embodiment, and a cylindrical connecting rubber elastic body 104 is vulcanized and bonded to the outer peripheral surface thereof, Further, a metal sleeve 106 is vulcanized and bonded to the outer peripheral surface of the connecting rubber elastic body 104. When the metal sleeve 106 is press-fitted and fixed to the opening of the first lid 98, the diaphragm 102 is elastically connected to the first lid 98 via the connecting rubber elastic body 104. It is connected and supported. The opening of the first lid 98 is the diaphragm 1
02, the first lid 9
Inside 8, a pressurizing chamber 108 is formed in which a part of the wall is formed of the diaphragm 102 and in which an incompressible fluid is sealed.

Further, the pressurizing chamber 108 is
2, an actuator 110 is provided on the opposite side of
It is housed and arranged in the device housing 101. The actuator 110 has the same structure as that of the first embodiment, and one end of the magnetostrictive element 112 in the axial direction is
And the other end in the axial direction of the magnetostrictive element 112 is fixed to the second lid 100 via an end member 116, and is axially fixed by a coil spring 118. Compression load is applied. A bobbin 122 around which a coil 120 is wound is extrapolated and fixed to the end member 116 in the magnetostrictive element 112. When an alternating current is applied to the coil 120, the deformation of the magnetostrictive element 112 causes vibration. The vibration plate 102 is vibrated by being exerted on the plate 102 so that the pressure chamber 10
8, a pressure change is caused to occur.

Further, at the center of the bottom wall of the first lid 98 constituting the wall of the pressurizing chamber 108, a port 124 projecting outward is formed.
4, the pressure of the pressurizing chamber 108 can be taken out. And this port section 12
4 and a port 95 formed in an arm eye forming a wall of the main liquid chamber 76 are connected by a pressure pipe 126, whereby the main liquid chamber 76 and the pressurizing chamber 108 are connected.
Are communicated with each other. The pressure tube 126 may be a rubber tube, a resin tube, a metal tube, or the like, and the material and the like are not limited at all. Considering the handling and the like, a flexible material is desirable. However, the pressure tube 126
In order to ensure sufficient pressure transmission efficiency between the main liquid chamber 76 and the pressure chamber 108 without being absorbed in pressure by the deformation of The characteristics that are not allowed are adopted. In this embodiment, a tubular body made of a thick rubber elastic body is adopted, and both ends are externally inserted into the respective port portions 95 and 124, and are connected and fixed in a fluid-tight manner by the tightening belt 128. Have been.

In particular, in the present embodiment, the fluid flowing through the pressure pipe 126 based on the pressure difference between the main liquid chamber 76 and the pressurizing chamber 108 causes the natural vibration in the frequency range corresponding to the vibration frequency to be damped. The length and cross-sectional area of the pressure pipe 126 are set so as to take into account the wall spring rigidity of the main liquid chamber 76 and the like. As a result, in the natural frequency range of the fluid, fluid flow through the pressure pipe 126 is positively generated, and the pressurizing chamber 108 and the main liquid chamber 7 are generated.
The pressure transmission between 6 can be made more aggressive or efficient.

In the suspension arm 70 of the present embodiment having the above-described structure, similarly to the suspension arm of the first embodiment, the rubber bush 74 and the suspension are controlled by controlling the internal pressure of the main liquid chamber 76. The vibration isolating characteristics of the arm 70 can be adjusted. Therefore, the current supplied to the coil 120 of the pressure generator 78 is controlled according to the vibration input to the rubber bush 74 to be damped. By vibrating the plate 102 at an appropriate cycle and stroke, a pressure fluctuation is generated in the pressurizing chamber 108, and the pressure fluctuation is transmitted through the pressure pipe 126 to the main liquid chamber 7.
By virtue of this, an active vibration damping effect is exhibited against input vibration.

In particular, in the suspension arm 70 of the present embodiment, the pressure control of the main liquid chamber 76 can be more efficiently realized based on the resonance action of the fluid flowing through the pressure pipe 126. In addition, a more excellent vibration-proof effect is exerted against the vibration to be damped.

Also, in the suspension arm 70 of the present embodiment, the static spring constant or the static spring constant or It is possible to set a large dynamic spring constant for low-frequency vibrations, thereby achieving a high degree of compatibility between vehicle ride comfort and steering stability, etc., similar to the suspension arm of the first embodiment. The effects are all exerted effectively.

In the suspension arm 70 of the present embodiment, the actuator 110 for controlling the internal pressure of the main liquid chamber 76 is formed independently of the arm member 72 as the pressure generating device 78. Is more secured than the suspension arm of the first embodiment. For example, the pressure generating device 78 can be used with respect to another member separate from the arm member 72. It can also be worn. In particular, by adopting the flexible pressure tube 126, it is possible to realize attachment to a member that moves differently from the arm member 72. Thereby, the magnetostrictive element 112
Set the dimension in the output stroke direction of
By securing a large output stroke and, consequently, a large internal pressure control amount of the main liquid chamber 76, it is possible to further improve the vibration isolation performance.

Next, FIG. 3 shows a suspension arm 130 as a third embodiment of the present invention. The suspension arm 130 is a specific example in which the suspension arm of the first embodiment employs a different structure as the second rubber bush. Therefore, only the main part is shown, Members and portions having the same structure as the suspension arm of the embodiment are denoted by the same reference numerals in the drawing as those of the suspension arm of the first embodiment, and detailed description thereof will be omitted.

That is, in the second rubber bush 132 mounted on the second arm eye 36 in the suspension arm 130 of the present embodiment, the inner and outer cylindrical fittings 134 and 136 which are radially separated from each other are formed by the main rubber. It is formed by being elastically connected by an elastic body 138, and has a basic structure similar to that of the second rubber bush in the first embodiment. There, outer tube fitting 1
36, a first opening window 140 and a second opening window 142 are formed at portions opposed to each other in the radial direction,
The main rubber elastic body 138 has a first pocket portion 144 and a second pocket portion 146 formed at portions opposed to each other in the radial direction, and the first pocket portion 144 passes through the first opening window 140. The second pocket portions 146 are respectively opened on the outer peripheral surface through the second openings 142.

The first and second opening windows 140 and 142 in the outer cylinder fitting 136 are connected to the second arm eye 36.
The main liquid chamber 38 and the sub liquid chamber 14 each having a non-compressible fluid sealed therein by being fluid-tightly closed by
8 are formed. That is, the sub liquid chamber 148 is connected to the main liquid chamber 3.
8 is positioned in the radial direction, which is the main vibration input direction, with the inner cylinder fitting 134 interposed therebetween. An internal pressure change in which the sign is substantially opposite is generated between the liquid chamber 38 and the sub liquid chamber 148, and a relative internal pressure change is caused.

The outer tube fitting 13 of the rubber bush 132
6 has a first opening window 140 at the axially intermediate portion.
A concave groove 150 extending across one circumferential end of the second opening window 142 and the second opening window 142 is formed to open on the outer peripheral surface. The concave groove 150 is covered with the second arm eye 36 in a fluid-tight manner, so that an orifice passage 152 that connects the main liquid chamber 38 and the sub liquid chamber 148 to each other is formed. Here, the orifice passage 1
Reference numeral 52 takes into account the wall spring stiffness of the main liquid chamber 38 and the sub liquid chamber 148 so that the natural frequency (resonance frequency) of the fluid flowing through the interior thereof corresponds to the frequency of the vibration to be damped. The passage length and passage cross-sectional area of the orifice passage 152 are set.

In the suspension arm 130 of this embodiment having such a structure, the fluid flowing through the orifice passage 152 is formed based on the pressure difference generated between the main liquid chamber 38 and the sub liquid chamber 148 at the time of vibration input. A flow is generated, so that a low dynamic spring effect is exerted based on the resonance action of the fluid caused to flow through the orifice passage 152, thereby achieving excellent vibration damping performance against vibration to be damped. It is done.

The vibration damping effect based on the resonance action of the fluid caused to flow through the orifice passage 152 can be exerted even when the internal pressure of the main liquid chamber 38 is not controlled by the vibration of the diaphragm 42. By controlling the internal pressure of the main liquid chamber 38 by vibrating the vibration plate 42 in the tuning frequency range of the passage 152, the main liquid chamber 38 and the sub liquid chamber are resonated by the fluid flowing through the orifice passage 152. The active anti-vibration effect based on the pressure control of 148 is more advantageously exerted.

The embodiments of the present invention have been described in detail above, but these are literal examples, and the present invention
By specific description of these embodiments,
It is not to be construed as limiting.

For example, in each of the above embodiments, a specific example in which a magnetostrictive element is used as an actuator has been described, but an actuator using an electrostrictive element may be used instead. In addition, as an electrostrictive element,
For example, as described in Japanese Patent Publication No. 2510919, an inverse piezoelectric effect such as that formed using a piezo ceramic mainly containing lead (Pb), zirconium (Zr), titanium (Ti) or the like. Any known one that can exhibit the above-mentioned can be adopted, but in particular, a large number of piezo-ceramics are laminated, and a vertical effect that is expansion and contraction deformation in the laminating direction is used, a so-called laminated type, It is preferably employed because of its large generating force. Further, since the laminated electrostrictive element generally has a low tensile strength in the laminating direction, the pressing force (pre-press) in the laminating direction is utilized by using the urging force of a coil spring or the like as in the magnetostrictive element in the above embodiment. Compression).
Thereby, the durability and reliability of the electrostrictive element can be improved.

Further, in the above-described embodiment, only the vibration-isolating bush on the side attached to one of the members can actively adjust the vibration-isolating characteristics by controlling the internal pressure of the main liquid chamber. In the anti-vibration bush arranged at the attachment site to both connected members,
It is possible to adopt a device capable of actively adjusting the vibration isolation characteristics by controlling the internal pressure of the main liquid chamber. Further, the present invention provides
The present invention can be applied to an arm member having various structures interposed between members connected for vibration isolation in various devices for automobiles or non-vehicles. Any structure may be used as long as the vibration bush is mounted, and the structure of the other mounting portions is not limited at all, and a connection structure using a pillow ball or a sliding bush, a rigid connection structure, or the like may be employed.

Further, in order to more effectively secure the internal pressure control efficiency of the main liquid chamber by the diaphragm, for example, it is effective to set the effective piston area of the diaphragm to be larger than the effective piston area of the shaft member. . The effective piston area of the diaphragm is the amount of fluid discharged from the main liquid chamber or the pressurizing chamber when the diaphragm is displaced by a unit amount in the vibration direction under a reference state such as an arm mounted state. The effective piston area of the shaft member refers to the amount of fluid discharged from the main liquid chamber when the shaft member is displaced by the same unit amount under the same conditions.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements, and the like can be made, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[0063]

As is apparent from the above description, in the arm member with the vibration isolating bush having the structure according to the present invention, the vibration isolating characteristic is obtained by vibrating the diaphragm and controlling the pressure of the main liquid chamber. Since the actuator to be adjusted is attached to the arm member or to another member separate from the arm member, the degree of freedom in setting the arrangement space of the actuator is advantageously secured, and therefore, Even in an arm member having a limited shape and size, an anti-vibration bush capable of active anti-vibration control can be advantageously used, and excellent anti-vibration performance can be realized.

Particularly, by employing an actuator using a strain element as an actuator for vibrating the diaphragm, excellent response speed, easy control, and a large driving force can be easily obtained. It is possible to advantageously set the output stroke of the strain element by using the space for the actuator which is advantageously secured, while sufficiently securing the advantage of the strain element, thereby controlling the internal pressure of the main liquid chamber. Therefore, the vibration damping effect based on the above is more advantageously exhibited.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a suspension arm as a first embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view showing a main part of a suspension arm as a second embodiment of the present invention.

FIG. 3 is an explanatory longitudinal sectional view showing a main part of a suspension arm as a third embodiment of the present invention.

[Explanation of symbols]

 10, 70, 130 Suspension arm 12 Rod portion 14 First rubber bush 16, 132 Second rubber bush 26, 134 Second inner cylinder fitting 28, 136 Second outer cylinder fitting 30, 138 Second body rubber Elastic body 36 Second arm eye 38,76 Main liquid chamber 42,102 Vibrating plate 44,104 Connecting rubber elastic body 52,110 Actuator 54,112 Magnetostrictive element 68,120 Coil 72 Arm member 74 Rubber bush 78 Pressure generator 82 Arm eye 84 inner cylinder fitting 86 outer cylinder fitting 88 main rubber elastic body 108 pressurizing chamber 126 pressure pipe 148 sub-liquid chamber 152 orifice passage

Claims (4)

[Claims] 1. An anti-vibration bush in which a shaft member and an outer cylindrical member are connected by a main rubber elastic body is assembled to an arm member connecting two members, and via the anti-vibration bush,
An arm member with a vibration isolating bush adapted to be attached to a member to which the arm member is to be connected, wherein a part of a wall portion is formed of the main rubber elastic body with respect to the vibration isolating bush and is not compressed inside Forming a main liquid chamber in which a sexual fluid is sealed, and another part of the wall of the main liquid chamber,
An actuator using a strain element that is deformed by a change in an electric field or a magnetic field is mounted on the arm member while the diaphragm is configured to be displaceably supported by the outer cylinder member, and the diaphragm is attached to the arm member. An arm member with an anti-vibration bush, wherein the internal pressure of the main liquid chamber is controlled by applying vibration. 2. An anti-vibration bush in which a shaft member and an outer cylindrical member are connected by a main rubber elastic body is attached to an arm member connecting the two members, and via the anti-vibration bush,
An arm member with a vibration isolating bush adapted to be attached to a member to which the arm member is to be connected, wherein a part of a wall portion is formed of the main rubber elastic body with respect to the vibration isolating bush and is not compressed inside Forming a main liquid chamber in which a compressive fluid is sealed, a pressurizing chamber in which a part of a wall is formed of a diaphragm supported so as to be displaceable and in which an incompressible fluid is sealed, Or, an actuator using a strain element that is deformed by a change in a magnetic field is provided, and a pressure generator that generates a pressure change in the pressurizing chamber by vibrating the diaphragm with the actuator is provided. A fluid conduit communicating the pressurizing chamber with the main liquid chamber of the vibration isolating bush is provided, and the internal pressure of the main liquid chamber is controlled by the vibration of the vibration plate by the actuator in the pressure generating device. West An arm member with a vibration-proof bush. 3. A flow path length and a flow path cross-sectional area of the fluid conduit are set so that a resonance frequency of the incompressible fluid caused to flow through the fluid conduit corresponds to a vibration frequency to be damped. The arm member with a vibration-isolating bush according to claim 2, wherein the arm member is provided. 4. An incompressible fluid is sealed in the vibration isolating bush, in which a relative pressure change is generated between the main liquid chamber and the main liquid chamber independently of the main liquid chamber. The arm member with a vibration-isolating bush according to any one of claims 1 to 3, wherein a sub liquid chamber is formed, and an orifice passage communicating the main liquid chamber and the sub liquid chamber with each other is formed.