JP2001304331A - Variable damping element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable damping element, having superiors response performance by changing pressure contact force to a friction face by an actuator using a piezoelectric element. SOLUTION: A friction damper comprises an acceptor 3 and a moving body 4, inserted in a freely projecting and receding manner in the acceptor 3. The acceptor 3 is formed into cylindrical shape, and the moving body 4 is inserted in the inner part 3a of the acceptor 3 with a slight clearance. A brake pad 5 for applying frictional resistance force to the moving body 4, a piezoelectric actuator 6 for controlling the pressing force of the brake pad 5 to the moving body 4, and a pressure sensor 7 for detecting the pressing force of the brake pad 5 from reaction when pressing the brake pad 5, are provided between the acceptor 3 and the moving body 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping element for providing resistance to the relative movement between two objects that are relatively close to and away from each other, and more particularly to a variable damping element that varies the added resistance value.

[0002]

2. Description of the Related Art An anti-vibration device is a base to which vibrations of the ground and floor are input, and a vibration-damping object such as a building, precision equipment, other equipment or devices that dislike vibration, and articles installed on the base. A so-called period increasing means is provided between the base and the vibration-isolating target object. The vibration input to is reduced.

[0003] As a means for prolonging the period, various types of spring bearings such as a rubber spring and an air spring are used when horizontal vibrations are isolated, and when vertical vibrations are isolated. I have. Also, there is known a vibration isolator designed to perform three-dimensional vibration isolation by combining the elastic bodies for horizontal vibration isolation and vertical vibration isolation.

[0004] When the object to be isolated is a building, there are earthquakes and winds as input vibrations. In order to effectively eliminate the vibrations caused by the earthquakes and the wind by the vibration isolation device, the vibrations must be isolated. It is desirable to configure the device as a semi-active damping device. This semi-active vibration damping device is provided with a main part of passive vibration damping while reducing the vibration of an object to be vibration-isolated by actively changing a property of a damping element of the vibration damping device, for example, a damping element. Even if the active control part does not function due to damage or power failure,
Fail safe can be ensured by exhibiting the original passive vibration damping function.

[0005]

As a conventional damping element, an oil damper filled with an incompressible fluid is generally used, and the damping force of the oil damper is controlled by opening and closing an orifice with a solenoid valve. Will be However, when control is performed by opening and closing the orifice in this way, a response delay occurs in the reaction time from when the control command signal is output to the solenoid valve until the damping force of the oil damper substantially changes, resulting in a fine semi-conductor. It was impossible to perform active control.

In addition to the oil damper, a friction damper that generates a damping force by frictional resistance can be used as the damping element. In this case, in order to change the frictional force of the friction damper, the pressing force against the friction surface is controlled by the actuator using the hydraulic pressure, but even in this case, the response is delayed due to the use of the hydraulic pressure. Is generated, and it is difficult to perform effective semi-active control.

The present invention has been made in view of such a conventional problem, and provides a variable damping element excellent in response performance by changing a pressing force against a friction surface using an actuator using a piezo element. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION A variable damping element according to the present invention is disposed between two objects that are relatively approaching and moving away from each other and adds resistance to the relative movement of the two objects. And the other object,
A moving body provided to be relatively movable with respect to the receptor, a brake pad provided on the receptor to apply a frictional resistance to the moving body, and a brake pad provided between the brake pad and the receptor. A piezo actuator for pressing a brake pad against the moving body.

In this case, the receiver and the moving body move relative to each other as the two objects relatively approach and separate from each other. At this time, the brake pad is pressed against the moving body by the piezo actuator, so that the frictional resistance is reduced. A force can be generated to attenuate the relative movement of the two objects. The piezo actuator is configured by using a piezo element, and is instantaneously displaced by application of a voltage, and the amount of this displacement is changed according to the level of the applied voltage. Therefore, when a control voltage is applied to the piezo actuator, the brake pad can be pressed against the moving body according to the displacement amount corresponding to the voltage, and a desired frictional resistance can be generated on the moving body. At this time, the piezo actuator is instantaneously displaced by the application of the voltage, and the displacement is transmitted to the moving body via the rigidly displaced brake pad, thereby eliminating a response delay in the force transmission path. The response from the output of the control voltage to the occurrence of the attenuation is significantly improved.

[0010] Further, a pressure sensor for detecting a pressing force of the brake pad against the moving body is provided in the receiver, and a voltage applied to the piezo actuator is controlled by a detection value of the pressure sensor. And

In this case, since a control voltage corresponding to the detection value of the pressure sensor is applied to the piezo actuator,
The pressing force of the brake pad can be precisely controlled, and more accurate damping control can be performed.

Further, a spring bearing is provided between the two objects to constitute a vibration isolator.

In this case, a spring system for elastically supporting one of the two objects via the spring bearing is formed, and the object on the elastically supported side can be isolated. At this time, the vibration is attenuated by the frictional resistance force of the variable damping element disposed between the two objects. However, since the vibration can be generated and controlled by a piezo actuator having a high response, high precision can be achieved. Semi-active control can be secured.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the variable damping element according to the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3 show the variable damping element 1 of the present embodiment, and FIG. 4 shows a vibration isolator 2 to which the variable damping element 1 is applied. That is, the variable damping element 1 is configured as a friction damper having a receiver 3 and a moving body 4 inserted into and out of the receiver 3 as shown in FIG. The receiving body 3 is formed in a cylindrical shape with one end closed, and the moving body 4 is formed as a rod-like body fitted into the inside 3a of the receiving body 3 with a small gap.

[0015] Between the receptor 3 and the moving body 4,
Brake pad 5 for applying frictional resistance to moving body 4
A piezo actuator 6 for controlling the pressing force of the brake pad 5 on the moving body 4 and a pressure sensor for detecting the pressing force of the brake pad 5 on the moving body 4 from the reaction force when the brake pad 5 is pressed 7 is interposed. The brake pad 5, the piezo actuator 6, and the pressure sensor 7 are arranged in a stacked state from inside to outside as shown in a longitudinal sectional view of FIG. 2 in this order, and as shown in an enlarged sectional view of FIG. Are formed as concentric cylinders. The concentrically arranged brake pad 5, piezo actuator 6, and pressure sensor 7 are fitted and supported in an enlarged diameter portion 3b formed on the inner side 3a near the opening end of the receiver 3. The concentric brake pad 5, piezo actuator 6,
A slit 8 is formed in a part of the pressure sensor 7 to allow these expansion and contraction deformations.

The piezo actuator 6 is constructed by stacking a plurality of thin piezo elements sandwiched between electrode plates using piezo elements that generate displacement when a voltage is applied. By applying a voltage to the electrode plates at both ends of the piezo element, each piezo element is displaced in the direction of the electrode plate (in the direction of increasing the thickness) by the inverse piezoelectric effect, and the piezo actuator 6 integrates the displacement of each piezo element. Is displaced by the determined displacement amount.
Further, the displacement generated in the piezo element also changes depending on the level of the applied voltage, and a large displacement is generated in the piezo actuator 6 by applying a high voltage. A control voltage output from the controller 9 is applied to the piezo actuator 6 as shown in FIG.

The pressure sensor 7 is located between the outer periphery of the piezo actuator 6 and the inner periphery of the enlarged diameter portion 3b, and receives a reaction force when the brake pad 5 is pressed by the displacement of the piezo actuator 6. Has become. The pressure sensor 7 is configured using a piezo element similarly to the piezo actuator 6, and utilizes a piezoelectric effect of the piezo element, and outputs a voltage according to a loaded force, that is, a reaction force of the piezo actuator 6. It is supposed to. Further, the pressure sensor 7 is not limited to the piezo element for extracting a voltage from an input force.
It may be of a strain gauge type that measures strain caused by displacement. Then, a detection value of the pressure sensor 7, for example, a voltage when a piezo element is used, is input to the controller 9, whereby the voltage applied to the piezo actuator 6 is controlled. The control method is
Any of feedback and feed forward may be used.

The variable damping element 1 can be used as damping means of the vibration isolator 2 shown in FIG. That is, the vibration isolation device 2 is configured as a three-dimensional vibration isolation device, and a reinforced concrete foundation 11 is provided above a reinforced concrete foundation 11 as a base to which vibration such as an earthquake including a vertical vibration component and a horizontal vibration component is input. The upper foundation 12 is built.
A building 13 as a vibration isolation target is constructed above the upper foundation 12, and the building 13 is provided on the foundation 11 via the upper foundation 12. The upper foundation 12 is the building 1
A vertical wall 12a is formed in an annular shape along the circumferential direction on an outer peripheral edge portion of the lower wall of the lower wall 3 so as to surround a lower portion of the lower wall 3 and is formed in a dish shape.

Between the foundation 11 and the upper foundation 12, there is provided a horizontal vibration isolator 14 for supporting the weight of the building 13 and the upper foundation 12 and isolating horizontal vibrations. Between building 13 and building 13
A vertical vibration isolating device 15 for supporting vertical weight while supporting the weight of the vehicle is provided.

The horizontal vibration isolator 14 is mainly composed of a plurality of horizontal spring bearings, for example, a laminated rubber 16 provided at intervals in a vertical gap V between the foundation 11 and the upper foundation 12 on the building side. And a horizontal damping means, for example, a hydraulic damper 17, which is horizontally arranged to damp horizontal vibrations. The upper and lower ends of the laminated rubber 16 are integrally fixed to the upper foundation 12 and the foundation 11, respectively, and the upper foundation 12 can be horizontally moved relative to the foundation 11 while bearing the weight of the building 13. , Elastically deforms in the horizontal direction due to horizontal vibration transmitted from the foundation 11 to isolate the horizontal vibration. The hydraulic damper 17 has a base 1 at both ends.
1 and a support 17b suspended from the upper foundation 12 to join the foundation 11 and the upper foundation 12 with each other.
Is expanded and contracted by the horizontal relative movement of, and attenuates horizontal vibration.

Although the hydraulic damper 17 is used as the horizontal damping means, other means capable of exhibiting a damping action in accordance with a change in the distance between two objects, such as a friction damper, a steel rod damper, and a viscoelastic material are used. A damper or the like can also be used.

The vertical vibration isolator 15 is mainly used for building 1
Vertical gap W between the base 3 and the upper foundation 12 on the foundation side
A plurality of vertical spring bearings provided at a distance from each other, for example, an air spring 18 that enables a longer period of the building 13, and an inner peripheral wall surface of the vertical wall 12 a of the upper foundation 12 and a side surface of the building 13. A plurality of compression spring means, for example, compression coil springs 19 are provided at intervals in the horizontal gap C between the front and rear and left and right so as to surround the building 13. Here, a plurality of the variable damping elements 1 are provided in the vertical gap W adjacent to the air spring 18 at intervals.

The upper and lower ends of the air spring 18 are integrally fixed to the upper foundation 12 and the building 13, respectively. By elastically supporting the base 12 so as to be vertically movable relative to each other, the vertical vibration transmitted from the foundation 11 via the upper foundation 12 elastically deforms in the vertical direction, thereby isolating the vertical vibration. In this case, the air spring 18 is used as the vertical spring support, but other means that can elastically support the building 13 in the vertical direction, such as a disc spring and a coil spring, can be used.

The left and right ends of the compression coil spring 19 are respectively formed on the side surface of the building 13 and the vertical wall 1 of the upper foundation 12.
The inner peripheral wall 2a is coupled to the inner peripheral wall by a pin joint 20 so as to be rotatable at least around a horizontal axis, so that it can be tilted up and down and only an axial force is applied. Further, the compression coil spring 19 is provided between the side wall of the building 13 and the vertical wall 12a.
Is formed to be longer than the dimension of the horizontal gap C with the inner peripheral wall surface, and is arranged in the gap C horizontally in a compressed state. That is, the compression coil spring 19 in the compressed state is such that when the building 13 is at rest, the resilient force acts on the vertical wall 12a and the building 13 from the horizontal direction to the vertical direction.
It is installed in the horizontal gap C between the vertical wall 12a and the building 13 at the shortest distance and perpendicularly to these. In response to the vertical movement of the building 13 with respect to the upper foundation 12, the compression coil spring 19 is tilted obliquely and can be extended in order to restore the compressed state to the natural length from the compressed state. The compression coil spring 19 tilted in this manner
Causes not only a component force acting vertically on both the upper foundation 12 and the building 13, but also a component force causing a vertical relative movement between the upper foundation 12 and the building 13. The vertical relative movement with the upper foundation 12 can be promoted.

As shown in FIG. 1, the variable damping element 1 has a spherical portion 3c formed at the closed end of the receiver 3 and a spherical portion 4a formed at the protruding end of the moving body 4. These spherical portions 3c and 4a are used for building 13 as shown in FIG.
And the upper foundation 12 are connected to each other while forming a ball joint 21. Therefore, the moving body 4 is relatively moved while protruding and retracting with respect to the receiver 3 by the vertical relative movement between the building 13 and the upper foundation 12 which approach and separate relatively. At this time, when a control voltage is applied to the piezo actuator 6, the displacement generated in the piezo actuator 6 presses the brake pad 5 against the moving body 4 to generate a frictional resistance, which acts as a damping force for vertical vibration. It is supposed to.

In the three-dimensional vibration isolator 2 of the present embodiment having the above-described configuration, when an earthquake or the like including a horizontal vibration component and a vertical vibration component is input to the foundation 11, the horizontal vibration isolation is performed for the horizontal vibration component. The device 14 and the vertical vibration isolator 15 exhibit a vibration isolating function for the vertical vibration component.

That is, the horizontal vibration component causes the upper foundation 12 to vibrate horizontally relative to the foundation 11, and at this time, the laminated rubber 16 elastically deforms in the horizontal direction while the hydraulic damper 17 attenuates the horizontal vibration. Thus, the horizontal vibration input to the building 13 via the upper foundation 12 is isolated. The vertical vibration component causes the building 13 to vibrate vertically with respect to the upper foundation 12, and at this time, the air spring 18 elastically deforms vertically while the variable damping element 1 attenuates the vertical vibration. The vertical vibration input to the building 13 is isolated.

At this time, in response to the vertical movement of the building 13 relative to the upper foundation 12, in response to the vertical movement, the compression coil spring 19 is moved through the pin joints 20 at both ends thereof in a horizontal plane. Is naturally tilted obliquely, and expands to restore the compressed state to its natural length. The tilted compression coil spring 19 generates not only a component force acting vertically on both the upper foundation 12 and the building 13, but also a component force causing a vertical relative movement between the upper foundation 12 and the building 13. And compression coil spring 1
Until 9 restores to its natural length, the component force that induces the vertical movement of this latter is due to the building 13
In the direction of relative movement of the upper foundation 12
When moving relatively upward, it acts upward, and when moving relatively downward, acts downward to promote the relative movement between the two.

As described above, the compression coil spring 19 generated by the relative movement of the building 13 and the upper foundation 12 in the vertical direction.
In the vertical direction, and the increase in the amount of displacement in the vertical relative movement direction between the upper foundation 12 and the building 13 appearing according to this elastic force are input from the foundation 11 via the upper foundation 12. The vertical vibration of the air spring 18 promotes the elastic deformation of the air spring 18 which has already undergone considerable elastic deformation in the vertical direction, thereby increasing the amount of elastic deformation. Due to the increase in the amount of elastic deformation, it is possible to secure a longer vertical vibration isolation cycle that cannot be obtained by the air spring 18 that supports the weight of the building 13 alone.

With the above configuration, the variable damping element 1 of the present embodiment is applied to the vibration isolator 2 having the horizontal vibration isolator 14 and the vertical vibration isolator 15 and exhibiting a three-dimensional vibration isolating function. It is used as a damping means of the vertical vibration isolator 15. The variable damping element 1 uses an earthquake or wind as a vibration source for the upper foundation 12.
As the building and the building 13 approach and move away relatively,
The receptor 3 and the moving body 4 move relatively. At this time, the vibration state of the foundation 11, the upper foundation 12, the building 13, and the like is detected by a vibration sensor (not shown), and the controller 9 shown in FIG.
When the control voltage is applied to the piezo actuator 6, the piezo actuator 6 outputs a displacement amount corresponding to the control voltage, and the displacement causes the brake pad 5 to be pressed by the moving body 4 to generate a frictional resistance. Acts as a vibration damping force.

The piezo actuator 6 is constructed by using a piezo element, and has the property of being instantaneously displaced by the application of a voltage and having the property that the amount of displacement changes in accordance with the level of the applied voltage. The frictional resistance can be precisely controlled, and the instantaneous displacement of the piezo actuator 6 is transmitted to the moving body 4 through the rigidly displaced brake pad 5, so that the force transmission path Response lag can be eliminated. Therefore, the response from the output of the control voltage to the generation of the damping force is remarkably enhanced, and ideal semi-active control by the vibration isolation device 2 becomes possible.

When a voltage is applied to the piezo actuator 6 to displace it, the laminate of the brake pad 5, the piezo actuator 6, and the pressure sensor 7 is regulated such that its outer peripheral direction is the inner periphery of the enlarged diameter portion 3b. As a result, it is deformed so as to be reduced in diameter only in the inner diameter direction, but this reduction in diameter is smoothly allowed while narrowing the interval between the slits 8.

Further, the piezo actuator 6 is provided with a pressure sensor 7 for detecting the pressing force of the brake pad 5 against the moving body 4 by receiving a reaction force when the brake pad 5 is pressed. 7, the voltage applied to the piezo actuator 6 can be controlled. Therefore, the substantial pressing force applied from the piezo actuator 6 to the brake pad 5 can be precisely controlled, and more accurate damping force control can be performed. Further, by adopting the piezo actuator 6 having high response, not only the vibration of the basic (primary) vibration component of the input vibration but also the high-order (2) which could not be achieved in the past. Second and third order) frequency components can also be effectively attenuated with good response performance.

In the above embodiment, the building 13 has been described as an example of a vibration-isolated object. However, it is needless to say that precision equipment and other equipment, devices, and articles that dislike vibration may be used. It is.

In the vibration isolator 2 to which the variable damping element 1 is applied, the horizontal vibration isolator 14 is provided between the foundation 11 and the upper foundation 12, and the vertical vibration isolator 14 is provided between the upper foundation 12 and the building 13. The case where the vibration isolator 15 is provided as a three-dimensional seismic isolation structure and the variable damping element 1 is provided in the upper and lower vibration isolator 15 has been disclosed.
4 and the upper and lower vibration isolator 15 can be interchanged, and the variable damping element 1 of the present invention can be provided instead of the hydraulic damper 17 of the horizontal vibration isolator 14. Furthermore, the variable damping device 1 of the present invention can be applied to a vibration isolator other than the three-dimensional seismic isolation device 2, for example, a two-dimensional vibration isolator mainly including vertical vibration isolation.

Furthermore, in the above-described embodiment, an example has been described in which an earthquake is used as an input vibration. However, the same effect can be exerted by a traffic vibration, a daily vibration, and a mechanical vibration of a factory or the like. Of course.

Furthermore, the variable damping element 1 of the present invention is not limited to the vibration isolator, but can be applied to any structural part that attenuates the relative movement in the approaching / separating direction between two objects. .

[0038]

As described above, according to the variable damping element of the present invention, the piezo actuator, which instantaneously generates a displacement by applying a voltage, presses the brake pad against the moving body to perform frictional braking. And the damping force can be more precisely controlled.

Further, since a control voltage corresponding to the detection value of the pressure sensor is applied to the piezo actuator, the pressing force of the brake pad can be precisely controlled, and a more accurate damping control can be performed. Can be.

Further, when a spring system for elastically supporting one of the two objects via a spring bearing is configured to isolate the object on the elastically supported side, vibration damping is improved with good responsiveness. Since it can be generated and controlled by a piezo actuator, highly accurate semi-active control can be ensured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a variable damping element according to the present invention.

FIG. 2 is an enlarged sectional view showing an arrangement structure of a brake pad, a piezo actuator, and a pressure sensor used in the variable damping element of FIG.

FIG. 3 is an enlarged sectional view taken along line AA in FIG.

FIG. 4 is a schematic configuration diagram showing an embodiment of a vibration isolation device to which the variable damping element according to the present invention is applied.

[Description of Signs] 1 Variable damping element 2 Vibration isolation device 3 Receptor 4 Moving body 5 Brake pad 6 Piezo actuator 7 Pressure sensor 11 Foundation 12 Upper foundation 13 Building 18 Air spring

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F16F 7/08 F16F 7/08 H01L 41/09 H01L 41/08 U

Claims (3)

[Claims] 1. A damping element disposed between two relatively approaching / separating objects to add resistance to the relative movement of the two objects, wherein: a receptor provided on one object; A moving body provided to be relatively movable with respect to the receptor, a brake pad provided on the receptor to apply a frictional resistance to the moving body, and a brake pad provided between the brake pad and the receptor. A variable damping element, comprising: a piezo actuator for pressing a brake pad against the moving body. A pressure sensor for detecting a pressing force of the brake pad against the moving body, wherein a voltage applied to the piezo actuator is controlled by a detection value of the pressure sensor. The variable damping element according to claim 1, wherein 3. The variable damping element according to claim 1, wherein a spring bearing is provided between the two objects to constitute a vibration isolator.