JPH07293621A - Vibration isolation supporting device - Google Patents

Abstract

PURPOSE:To avoid resonance of an equipment by vibrational acceleration of a structure as well as preventing damage caused by excessive deformation of a vibration isolating rubber and damage of the equipment caused by collision of the structure with the equipment even when large acceleration is applied on the structure, in a device for supporting the equipment housed in the structure by the structure. CONSTITUTION:Non-linear springs 4 capable of changing their rigidity by adjusting the spring height (h) are used as spring elements for connecting a structure 1 to an equipment 2, and shape memory alloy wires 5 are laid between the structure 1 and the non-linear springs 4, so as to be taken as an actuator for adjusting the spring height (h) of the non-linear springs 4. The shape memory alloy wires 5 are made act as an actuator, and an electric wire 6 and a power source 7 for allowing electric current to flow to the actuator, and a switch 8 for turning on/off the electric current are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration support device for equipment that receives a large impact force, such as equipment for running on rough roads and underwater equipment that is dropped from the air.

[0002]

2. Description of the Related Art FIG. 10 is a conceptual diagram showing an example of a conventional anti-vibration support device. In this example, an anti-vibration rubber (3) is provided between the structure (1) and a device (2) built in the structure (1).
To make it difficult for the vibration G _{1 of the} structure to be transmitted to the device (2).

[0003]

In the conventional anti-vibration supporting device, when a large impact acceleration acts on the structure (1) (when dropped from the air and landing on the sea surface).
Since the relative displacement between the structure (1) and the device (2) becomes significantly large, this displacement exceeds the allowable displacement of the vibration isolator (3) and the vibration isolator (3) is damaged, or the structure ( 1)
And the device (2) may collide with each other and the device (2) may be damaged. Further, when the frequency ω of the vibration acceleration G ₁ of the structure (1) is close to the natural frequency ω _n determined by the device (2) and the antivibration rubber (3), resonance occurs and the device (2) As shown in FIG. 11, the vibration acceleration G ₂ becomes extremely large, and the function of the device (2) may be impaired.

According to the present invention, in a device for supporting a device built in a structure by the structure, even if a large acceleration is applied to the structure, damage due to excessive deformation of the anti-vibration rubber or damage to the structure and the device is prevented. The object of the present invention is to prevent the damage of the device due to the collision and to avoid the resonance of the device due to the vibration acceleration of the structure.

[0005]

In order to achieve the above-mentioned object, the present inventor proposes the following vibration-damping support devices [1], [2] and [3].

[1] A device for supporting a device built in a structure by means of a vibration-proof structure, wherein the device is attached to either one of the device and the structure and has a rigidity that changes with a change in spring height. A non-linear spring that changes, a shape memory alloy wire rod that is passed between the other and the non-linear spring and serves as an actuator that adjusts the height of the non-linear spring by contracting the length by heating, and a current is applied to the shape memory alloy wire rod. An anti-vibration support device comprising: a flow means and a switch for turning on / off the current.

[2] A device for supporting a device built in a structure by means of a vibration-proof structure, wherein the device is attached to either one of the device and the structure and has a rigidity that varies with a change in spring height. A changing non-linear spring, a spring provided between the other and the non-linear spring, a shape memory alloy wire rod whose length is reduced by heating, a means for passing an electric current through the shape memory alloy wire rod, the device and the structure. And a control device that adjusts the energization time of the current based on the vibration acceleration level and the vibration frequency detected by the vibration meter. Support device.

[3] A device for supporting a device built in a structure by means of the structure as described above, wherein the device is attached to any one of the device and the structure and has a rigidity that changes with a change in spring height. A changing nonlinear spring, a linear motion device provided between the other and the nonlinear spring to adjust the spring height of the nonlinear spring, a motor for driving the linear motion device, vibration of the device and the structure. An anti-vibration support device comprising: a vibrometer that detects acceleration and vibration frequency; and a control device that adjusts the rotation of the motor based on the vibration acceleration level and vibration frequency detected by the vibrometer.

[0009]

In the present invention, since the non-linear spring whose rigidity changes according to the change of the spring height is arranged between the structure and the device built in / supported by the structure, the height of the non-linear spring is reduced. By changing it, the supporting rigidity of the device can be changed. Therefore, in normal times, the supporting rigidity of the device by the non-linear spring is made small so that the vibration of the structure is difficult to be transmitted to the device, and the device is prevented from being damaged by the vibration. When a large impact acceleration acts on the structure, the rigidity of the non-linear spring is increased, that is, the supporting rigidity of the device is increased to prevent the structure from colliding with the device. When the frequency of vibration acceleration of the structure becomes close to the natural frequency determined by the equipment and the non-linear spring, the rigidity of the non-linear spring is changed to change the natural frequency of the system and cause resonance. To avoid.

As means for changing the height of the non-linear spring, in the solving means [1] and [2], a shape memory alloy wire is arranged between the non-linear spring and the structure or equipment, and the shape memory is A means for passing an electric current is provided in the alloy wire, and by turning this electric current on and off, the shape memory alloy wire is heated or cooled to change its length, and its tension is applied to the nonlinear spring. Further, in the solving means [2], not only the shape memory alloy wire rod is provided between the nonlinear spring and the structure or the device, but also the spring is provided, and the vibration acceleration and vibration frequency of the device and the structure are detected by the vibrometer. Since the control device adjusts the energization time of the current based on the detected value, the tension of the shape memory alloy wire and the restoring force of the spring are adjusted so that the spring height is obtained so that the nonlinear spring has appropriate rigidity. Can be automatically balanced.

In the solving means [3], the spring height of the non-linear spring is directly adjusted by a linear motion device driven by a motor. Then, similarly to the above-mentioned solving means [2], the vibration acceleration and the vibration frequency of the equipment and the structure are detected by the vibrometer, and the rotation of the motor is adjusted by the control device based on the detected values, so that the resonance and the excessive displacement are caused. Appropriate support rigidity capable of preventing the above is automatically obtained.

[0012]

【Example】

[First Embodiment] FIGS. 1 and 2 are conceptual views showing a first embodiment of the present invention. FIG. 1 shows a current off state and FIG. 2 shows a current on state. The device (2) built in the structure (1) and the structure (1) are coupled to each other via the anti-vibration rubber (3). In this embodiment, one of the device (2) and the structure (1) (device (2) in the illustrated example)
In addition, the non-linear spring (4) whose rigidity changes with the change in spring height is attached in a direction having rigidity in the vertical direction. Further, a shape memory alloy wire (5) is arranged between the other (the structure (1) in the illustrated example) and the nonlinear spring (4), and both ends of the shape memory alloy wire (5) are connected to the nonlinear spring (4). ) And the structure (1). The shape memory alloy wire (5) is provided with an electric wire (6) for supplying a current, a power supply (7), and a switch (8) for turning the current on and off. The length of the shape memory alloy wire rod (5) during shape memory is such that the spring height h of the non-linear spring (4) when the power is on is an appropriate value (the non-linear spring (4) has an appropriate vertical rigidity). Value)
Adjust so that

FIG. 3 is a diagram showing the restoring stress of the shape memory alloy wire rod. When tensile force is applied to the shape memory alloy wire,
When the temperature is low, strain (elongation) can be easily given, but when the temperature of the wire rod rises in the strained state, the wire rod shrinks in an attempt to return to its original shape. Since the shape memory alloy wire has an electric resistance, the temperature can be raised by passing an electric current.

Further, by increasing the spring height of the non-linear spring, the spring constant in the longitudinal direction can be increased as shown in FIG. FIG. 5 is a diagram showing an example of the shape of the non-linear spring. When the "height" in this figure is changed, the rigidity in the "length" direction changes. Therefore, as shown in FIG. 6, the non-linear spring (4) is attached to the device (2) so that the “length” direction is vertical, and the shape memory alloy (5) is attached.
If the "height" is changed by the restoring force of the structure,
The vertical support rigidity of the device (2) can be changed. That is, in the structure shown in FIG. 1, when a current is applied to the shape memory alloy wire (5), the shape memory alloy wire (5) contracts as shown in FIG. 2 and the spring height h of the nonlinear spring (4) increases. Therefore, the vertical support of the device (2) becomes rigid. When the electric current is turned off, the temperature of the shape memory alloy wire rod (5) decreases, the tension of the wire rod disappears, and the spring height h of the nonlinear spring (4) returns to the state shown in FIG. The support rigidity in the vertical direction also returns to the value in the state of FIG.

Therefore, when the structure (1) collides with the sea surface, the current is turned on to increase the rigidity of the nonlinear spring (4) in the vertical direction, that is, to increase the support rigidity of the device (2) to prevent the damage. The excessive deformation of the vibrating rubber (3) and the collision between the structure (1) and the device (2) are prevented. During normal operation, the current is turned off to reduce the support effect of the device (2) by the non-linear spring (4), and the vibration G ₁ of the structure (1) is transmitted to the device (2) by the antivibration rubber (3). To prevent damage to the device (2) due to vibration. Further, the frequency ω of the vibration acceleration G ₁ of the structure (1) is equal to that of the device (2).
When the resonance frequency is close to the natural frequency ω _n determined by the anti-vibration rubber (3) and the resonance occurs, the rigidity of the nonlinear spring (4) acts by turning on the current, so that the device (2)
The natural frequency determined by the vibration isolating rubber (3) changes, and resonance can be avoided.

[Second Embodiment] FIG. 7 is a conceptual diagram showing a second embodiment of the present invention. In the present embodiment, the device (2) is coupled to the structure (1) via the anti-vibration rubber (3) and the linear guide (9) for restraining the displacement other than the vertical direction. The device (2) is equipped with a non-linear spring (4) whose rigidity changes in accordance with the change in spring height in a direction having rigidity in the vertical direction. Further, a shape memory alloy wire (5) and a spring (10) are arranged between the nonlinear spring (4) and the structure (1), and both ends of the shape memory alloy wire (5) are connected to the nonlinear spring (4) and the structure ( Stick to 1). An electric wire (6) and a power supply (7) for passing an electric current are attached to the shape memory alloy wire (5). The spring height h of the nonlinear spring (4) (that is, the supporting rigidity of the device) is monitored by the non-contact displacement gauge (11). Further, vibrometers (12a) and (12b) are installed to monitor the vibration acceleration and frequency of the structure (1) and the device (2).

As described above, when a tensile force is applied to the shape-memory alloy wire, it easily distorts (elongates) at a low temperature.
However, when the temperature of the wire rod rises in the stretched state, the wire rod shrinks in an attempt to return to its original shape. Also, the nonlinear spring can increase the spring constant in the longitudinal direction by increasing the spring height. In this embodiment, the spring (10) and the shape memory alloy wire (5) are installed between the structure (1) and the non-linear spring (4), and the restoring force of the shape memory alloy wire (5) against the spring force is adjusted. By doing
It changes the support rigidity.

That is, in the structure shown in FIG. 7, if a current is applied to the shape memory alloy wire (5) so that the tension of the shape memory alloy wire exceeds the restoring force of the spring (10), the nonlinear spring (4) is obtained. Since the spring height h of the device (2) increases, the vertical support of the device (2) becomes rigid. When the electric current is turned off, the temperature of the shape memory alloy wire rod (5) decreases, the tension of the wire rod disappears, and the spring height (10) of the nonlinear spring (4) returns to its original value due to the action of the spring (10). The vertical support rigidity of the device (2) is reduced. Further, by applying a pulsed current as shown in FIG. 8 to the shape memory alloy wire (5) and adjusting the ratio (duty ratio) of the time when the current is on and the time when the current is off, the shape memory alloy wire (5) It is possible to change the ratio between the time when () has a shape memory effect and the time when it can easily give strain. In this embodiment, by adjusting the duty ratio of the power source (7) by the control device (14), the spring height h such that the nonlinear spring (4) has appropriate rigidity in the vertical direction can be obtained. The tension of the shape memory wire (5) and the restoring force of the spring (10) can be balanced.

Here, the vibrometer installed in the structure (1)
By monitoring the vibration acceleration at (12a), it becomes possible to determine the support rigidity according to the frequency ω of the vibration acceleration G ₁ of the structure (1). Further, by monitoring the vibration acceleration with the vibrometer (12b) installed in the device (2), the change in response acceleration can be fed back to the support rigidity determination routine. That is, in the arithmetic unit (13), from the output of the non-contact displacement gauge (11), the spring height h of the nonlinear spring (4), the rigidity of the nonlinear spring (4), the device (2) and the supporting device (anti-vibration rubber). The natural frequency of the system composed of (3) and the non-linear spring (4) is calculated. Further, the vibration acceleration level and the output frequency of the structure (1) and the device (2) are calculated from the outputs of the vibrometers (12a) and (12b). Then, the supporting rigidity capable of preventing resonance and excessive displacement is calculated, the duty ratio is determined, and an appropriate signal is output to the control device (14) that drives the power supply (7).

As described above, in this embodiment, the structure (1)
Vibration damping rubbers acceleration G ₁ in the frequency omega is a device (2) (3), the natural frequency omega _n determined by non-linear spring (4)
When a resonance occurs near to, resonance can be avoided by changing the natural frequency of the system by changing the rigidity of the nonlinear spring (4). Further, during normal operation, the spring height h of the non-linear spring (4) is reduced to reduce the supporting effect of the device (2) by the non-linear spring (4), and the structure (1) is provided by the anti-vibration rubber (3). Vibration G ₁ is difficult to be transmitted to the device (2) and the vibration causes the device (2)
It is possible to prevent damage. Further, when a large impact acceleration acts on the structure (1) (when it collides with the sea surface, etc.), the spring height h of the nonlinear spring (4) is increased to increase the vertical direction of the nonlinear spring (4). By increasing the rigidity, that is, by increasing the supporting rigidity of the device (2), it is possible to prevent excessive deformation of the vibration-proof rubber (3) and collision between the structure (1) and the device (2).

[Third Embodiment] FIG. 9 is a conceptual diagram showing a third embodiment of the present invention. As shown in this figure, the device (2) is coupled to the structure (1) through the vibration-proof rubber (3) and the linear guide (9) for restraining displacement other than the vertical direction. Further, a non-linear spring (4) whose rigidity changes with a change in spring height is attached to the device (2) in a direction having rigidity in the vertical direction. The process up to this point is the same as in the second embodiment, but in this embodiment, a linear motion device using a ball screw (15) is installed between the nonlinear spring (4) and the structure (1), and this is used as a motor ( By being driven by 16), the spring height h of the non-linear spring (4) can be adjusted. Then, a potentiometer (17) is installed to detect the rotation angle of the ball screw (15). Further, similarly to the second embodiment, vibrometers (12a) and (12b) are installed to monitor the vibration acceleration and frequency of the structure (1) and the device (2).

As described above, the nonlinear spring can increase the spring constant in the longitudinal direction by increasing the spring height. Therefore, in the apparatus having the structure shown in FIG. 9, if the ball screw (15) is driven by the motor (16) to increase the spring height h of the non-linear spring (4), the vertical support of the device (2) will be achieved. Become rigid. On the contrary, if the ball screw (15) is driven in the direction of decreasing the spring height h of the non-linear spring (4), the vertical support rigidity of the device (2) also decreases. Then, the vibrometer (1
By installing 2a) and monitoring the vibration acceleration, it becomes possible to determine the support rigidity according to the frequency ω of the vibration acceleration G ₁ of the structure (1). Further, by monitoring the vibration acceleration with the vibrometer (12b) installed in the device (2), the change in response acceleration can be fed back to the support rigidity determination routine. That is, arithmetic unit (18)
From the output of the potentiometer (17), the spring height h of the non-linear spring (4), the rigidity of the non-linear spring (4), the device (2) and the supporting device (the anti-vibration rubber (3) and the non-linear spring (4)) The natural frequency of the system is calculated. Further, the vibration acceleration level and the vibration frequency of the structure (1) and the device (2) are calculated from the outputs of the vibrometers (12a) and (12b). Then, the supporting rigidity capable of preventing resonance and excessive displacement is calculated, and an appropriate signal for driving the motor (16) is output.

As described above, also in this embodiment, the natural vibration in which the frequency ω of the vibration acceleration G ₁ of the structure (1) is determined by the device (2), the vibration-proof rubber (3) and the non-linear spring (4). When resonance occurs near the number ω _n , the rigidity can be changed to change the natural frequency of the system to avoid resonance. Further, during normal operation, the spring height h of the non-linear spring (4) is reduced to reduce the effect of supporting the device (2) by the non-linear spring (4).
The vibration isolating rubber (3) makes it difficult for the vibration G ₁ of the structure (1) to be transmitted to the device (2) and prevents the device (2) from being damaged by the vibration. Further, when a large impact acceleration acts on the structure (1) (when it collides with the sea surface, etc.), the spring height h of the nonlinear spring (4) is increased to increase the vertical direction of the nonlinear spring (4). By increasing the rigidity, that is, by increasing the supporting rigidity of the device (2), it is possible to prevent excessive deformation of the vibration-proof rubber (3) and collision between the structure (1) and the device (2).

[0024]

According to the present invention, the rigidity of the nonlinear spring is changed when the frequency of the vibration acceleration of the structure is close to the natural frequency determined by the equipment and the nonlinear spring and resonance occurs. As a result, resonance can be avoided by changing the natural frequency of the system. Also, during normal operation, the spring height of the non-linear spring can be reduced to reduce the device support effect of the non-linear spring, and it is possible to prevent the vibration of the structure from being transmitted to the device and prevent the device from being damaged by the vibration. . Further, when a large impact acceleration is applied to the structure, the spring height of the non-linear spring is increased to increase the vertical rigidity of the non-linear spring, that is, to increase the supporting rigidity of the device, thereby increasing the vibration damping rubber excessively. It is possible to prevent deformation and collision between the structure and the device.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a current off state according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a current-on state of the first embodiment.

FIG. 3 is a diagram showing a restoring stress of a shape memory alloy wire rod.

FIG. 4 is a diagram showing a relationship between a spring height and a spring constant of a nonlinear spring.

FIG. 5 is a diagram showing an example of the shape of a non-linear spring.

FIG. 6 is a side view showing a mounting state of the non-linear spring in the first embodiment.

FIG. 7 is a conceptual diagram showing a second embodiment of the present invention.

FIG. 8 is a diagram illustrating a duty ratio.

FIG. 9 is a conceptual diagram showing a third embodiment of the present invention.

FIG. 10 is a conceptual diagram showing an example of a conventional anti-vibration support device.

FIG. 11 is a diagram showing a vibration transmissibility from a structure to a device.

[Explanation of symbols]

(1) Structure (2) Equipment (3) Anti-vibration rubber (4) Non-linear spring (5) Shape memory alloy wire (6) Electric wire (7) Power supply (8) Switch (9) Linear guide (10) Spring (11) ) Non-contact displacement gauges (12a), (12b) Vibration meter (13) Computing device (14) Controller (15) Ball screw (16) Motor (17) Potentiometer (18) Computing device (h) Spring height (G ₁ ), (G ₂ ) Vibration acceleration

Claims (3)

[Claims] 1. A device for supporting a device built in a structure by a vibration-proof structure according to the structure, wherein the device is attached to any one of the device and the structure, and its rigidity changes as the spring height changes. A non-linear spring, a shape memory alloy wire rod which is passed between the other and the non-linear spring and serves as an actuator for adjusting the height of the non-linear spring by contracting the length by heating, and a current is passed through the shape memory alloy wire rod. Means and
An anti-vibration support device comprising: a switch for turning on / off the current. 2. A device for supporting a device built in a structure by means of the structure as described above, wherein the device is attached to one of the device and the structure, and its rigidity changes as the spring height changes. A non-linear spring, a spring provided between the other and the non-linear spring, and a shape memory alloy wire rod whose length is shortened by heating, a means for passing an electric current through the shape memory alloy wire rod, and the device and the structure. An anti-vibration support provided with a vibrometer for detecting vibration acceleration and vibration frequency, and a control device for adjusting the energization time of the current based on the vibration acceleration level and vibration frequency detected by the vibrometer. apparatus. 3. A device for supporting a device built in a structure with a vibration-proof structure by the structure, wherein the device is attached to any one of the device and the structure, and its rigidity changes as the spring height changes. And a linear motion device that is provided between the other and the nonlinear spring to adjust the spring height of the nonlinear spring, a motor that drives the linear motion device, and a vibration acceleration of the device and the structure. An anti-vibration support device comprising: a vibration meter for detecting a vibration frequency; and a control device for adjusting the rotation of the motor based on the vibration acceleration level and the vibration frequency detected by the vibration meter.