JP2019128209A - Vibration device and vibration test device with the vibration device - Google Patents

Abstract

To provide a vibration device and a vibrating test device having the vibration device capable of suppressing applying a weak vibration force in the decrease of the vibration force to the vibration object and reducing the impact load to the vibration object due to lowering the vibration force when the vibration rate applied to the vibrating object is large when reducing the vibration force to be applied to the vibration object.SOLUTION: The vibration device includes a signal generating unit for generating a command signal for vibrating the vibrating object at a predetermined frequency, a vibration unit for imparting vibration force to the vibration object on the basis of the command signal, a response signal acquisition unit for acquiring a response signal of vibration of the vibration object, and a phase difference detector for detecting the phase difference between the response signal and the command signal, and the vibration unit adjusts the timing of reducing the vibration force to be applied to the vibration object in response to the phase difference detected by the phase difference detection unit when reducing the vibration force to be applied to the vibration object.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an excitation apparatus and a vibration test apparatus provided with the excitation apparatus.

  In the conventional excitation apparatus for exciting the object to be excited, after the excitation object is vibrated by applying the excitation force, the vibration of the excitation object is reduced by reducing the excitation force. Stop it. Depending on the timing of stopping the vibration of the vibration target, the vibration target is applied by stopping the vibration when the weak vibration force with decreasing the vibration force is applied to the vibration target or the vibration speed is large. Impact load may be applied to the When this exciter is used as a component of a vibration test apparatus for testing the damped vibration characteristics of an object to be vibrated, if a weak exciter force or an impact load is applied when the vibration is stopped. Therefore, it becomes impossible to accurately determine the damped vibration characteristic of the object to be vibrated. On the other hand, Patent Document 1 discloses a vibration exciter capable of smoothly stopping vibration.

Japanese Patent No. 3627092

  However, if the vibration of the vibration target is smoothly stopped, although it is possible to suppress the impact load being applied at the time of stopping the vibration, the weak vibration force during the reduction of the vibration is applied to the vibration target. As a result, it becomes impossible to accurately determine the damping vibration characteristics of the vibration target.

  In view of the above-described circumstances, at least one embodiment of the present disclosure, when reducing the excitation force to be applied to the excitation object, a weak excitation force while reducing the excitation force is applied to the excitation object Vibrating device capable of reducing application of shock load to an object to be vibrated due to lowering of the vibrating force when it is applied or vibration speed is large, and vibration test apparatus equipped with this vibrating device The purpose is to provide.

(1) An excitation apparatus according to at least one embodiment of the present invention,
A signal generation unit that generates a command signal for causing the vibration target to vibrate at a predetermined frequency;
An excitation unit that applies an excitation force to the excitation target based on the command signal;
A response signal acquisition unit that acquires a response signal of the vibration of the vibration target;
A phase difference detection unit that detects a phase difference between the response signal and the command signal;
The excitation unit applies the excitation to the excitation object according to the phase difference detected by the phase difference detection unit when reducing the excitation force applied to the excitation object. It is configured to adjust the timing of reducing the shaking force.

  According to the configuration of the above (1), when the excitation force applied to the excitation object is reduced, the command signal for causing the excitation object to vibrate at a predetermined frequency and the response signal of the vibration of the excitation object Since the timing to reduce the excitation force applied to the excitation object is adjusted according to the phase difference with the above, it is possible to apply a weak excitation force to the excitation object while the excitation force is being reduced. Further, it is possible to reduce the impact load caused by lowering the excitation force when the vibration speed is high from being applied to the object to be excited.

(2) In some embodiments, in the configuration of (1) above,
The timing is a phase that is shifted by the phase difference from the phase at which the vibration speed of the vibration target becomes zero in the response signal.

  According to the configuration of the above (2), since the excitation force applied to the excitation object can be reduced at the timing when the vibration speed of the excitation object becomes zero, the impact load applied to the excitation object Can be reduced.

(3) In some embodiments, in the configuration of (1) or (2) above,
The predetermined frequency is a natural frequency of the vibration target.

  According to the configuration of (3) above, the object to be resonated resonates, so that the amplitude of the object to be excited can be increased even with a small excitation force.

(4) In some embodiments, in any one of the above configurations (1) to (3),
The excitation unit generates the excitation force by a reaction force in which an inertial mass vibrates.

  According to the configuration of the above (4), it is possible to easily install the excitation unit with respect to the excitation target object. Moreover, it can be used as an excitation apparatus for a vibration test apparatus.

(5) A vibration test apparatus according to at least one embodiment of the present invention includes:
Any of the vibration devices of (1) to (4) above;
And an analysis unit configured to determine a damping vibration characteristic of the vibration target based on the response signal after the vibration unit stops the vibration of the vibration target.

  According to the configuration of the above (5), when reducing the excitation force to be applied to the excitation object, a weak excitation force is being applied to the excitation object while the excitation force is being reduced, and the vibration velocity Since it is possible to reduce that an impact load caused by lowering the excitation force is applied to the object to be excited when Y is large, it is possible to accurately determine the damping vibration characteristic of the object to be excited.

(6) In some embodiments, in the configuration of (5) above,
In the response signal, based on the phase range after the phase when the vibration speed of the vibration target becomes zero immediately after the vibration unit stops the vibration of the vibration target, The analysis unit determines the damping vibration characteristic.

  When a stop signal is input, the residual pressure of the vibration device or the inertia of the vibration target remains, and the vibration force may not be completely zero. However, according to the configuration of (6) above, based on the phase range after the phase when the vibration speed of the vibration target becomes zero immediately after the vibration excitation unit stops the vibration of the vibration target Thus, the analysis unit determines the damped vibration characteristic, so that the influence of the remaining excitation force can be eliminated as much as possible to determine the damped vibration characteristic.

  According to at least one embodiment of the present disclosure, when reducing the excitation force applied to the excitation object, the command signal for causing the excitation object to vibrate at a predetermined frequency and the vibration of the excitation object Since the timing for reducing the excitation force to be applied to the excitation target is adjusted according to the phase difference with the response signal, the weak excitation force while the excitation force is being reduced is applied to the excitation target. In addition, it is possible to reduce the impact load caused by lowering the excitation force when the vibration speed is high from being applied to the object to be excited.

It is a block diagram showing composition of an excitation apparatus concerning one embodiment of this indication and a vibration test device. It is a typical graph which shows an example of the excitation force with respect to a command signal. It is a typical graph which shows an example of a command signal and a response signal. It is a typical graph which shows an example of a command signal and a response signal at the time of stopping vibration of an excitation subject. It is a schematic graph which shows another example of the excitation force with respect to a command signal.

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, and the like of components described in the following embodiments are not intended to limit the scope of the present invention, but merely illustrative examples.

  As shown in FIG. 1, a vibration test apparatus 10 according to an embodiment of the present disclosure includes an excitation apparatus 20 for oscillating an excitation target 1 and damping vibration characteristics of the excitation target, for example, a damping constant. And an analysis unit 30 for determining the The vibration device 20 generates a command signal for causing the vibration target 1 to vibrate at a predetermined frequency, and a vibration generator that applies a vibration force to the vibration target 1 based on the command signal. In order to adjust the excitation force, the response signal acquisition unit 23 that acquires the response signal of the vibration of the vibration target 1, the phase difference detection unit 24 that detects the phase difference between the response signal and the command signal, and And an operation unit 25 for the operator to operate. The analysis unit 30 is electrically connected to the response signal acquisition unit 23.

  The vibration unit 22 is a so-called inertia-type vibration exciter configured to generate a vibration force by a reaction force that vibrates the inertia mass. Since the exciter 22 is an inertia type exciter, the exciter 22 can be easily installed on the exciter 1. Therefore, the configuration of the exciter 20 is complicated. It can be suppressed. In addition, since the vibration unit 22 is an inertia type vibration exciter, the vibration device 20 can be used as a vibration device for the vibration test apparatus 10 by an operation described later.

Next, the operation of the vibration apparatus 20 will be described.
As shown in FIG. 1, when the operator operates the operation unit 25 to vibrate the vibration target 1, the signal generation unit 21 determines the vibration target 1 based on the operation conditions of the operation unit 25. A command signal for oscillating at the frequency is generated. Here, the predetermined frequency is preferably a single frequency, and can be, for example, the natural frequency of the vibration target 1. When the vibration target 1 is vibrated at its natural frequency, the vibration target 1 resonates, so the amplitude of the vibration target 1 can be increased even with a small vibration force.

  When a command signal is transmitted from the signal generation unit 21 to the excitation unit 22, the excitation unit 22 applies the excitation force based on the command signal to the excitation target 1 so that the excitation target 1 is Vibrate. During the vibration of the vibration target 1, the response signal acquisition unit 23 detects the speed or acceleration of the vibration of the vibration target 1, for example, and thereby the response signal of the vibration target 1 due to the application of the vibration force. To get In FIG. 2, as an example of the command signal, a displacement of the excitation unit 22 expressed as a sine wave is shown. An example of the transition of the excitation force based on this command signal is also shown.

  As illustrated in FIG. 1, the phase difference detection unit 24 determines the phase difference between the response signal and the command signal from the command signal transmitted from the signal generation unit 21 and the response signal transmitted from the response signal acquisition unit 23. The detected phase difference is transmitted to the signal generation unit 21. When the vibration target 1 vibrates at its natural frequency, the phase of the excitation force applied to the vibration target 1 and the phase of the response signal are shifted by 90 °. Therefore, as shown in FIG. 3, the phase of the command signal and the phase of the response signal are shifted by 90 °. Therefore, as shown in FIG. 1, the phase difference detected by the phase difference detection unit 24 is 90 °, and this phase difference is transmitted to the signal generation unit 21.

  When the operator operates the operation unit 25 to decrease the excitation force to stop the vibration of the excitation object 1, the signal generation unit 21 reduces the excitation force to be applied to the excitation object 1. Generates a command signal of However, if a command signal for reducing the excitation force to be applied to the excitation target 1 is generated according to the operation of the operator, depending on the timing, the weak excitation force during the reduction of the excitation force is An impact load resulting from being applied to the vibration target 1 or reducing the vibration force when the vibration speed is high is applied to the vibration target 1.

  In order to prevent application of the weak excitation force during the reduction of the excitation force to the excitation object 1, it is necessary to decrease the excitation force in as short time as possible, that is, instantaneously. On the other hand, in order not to apply an impact load to the excitation object 1, the timing at which the vibration velocity of the excitation object 1 is zero, and the response signal shown in FIG. The excitation force may be reduced at the timing at which it becomes, for example, the phase of A. However, as described above, since the phase of the command signal and the phase of the response signal are shifted by 90 °, the excitation force is not reduced at the phase of A, but the amplitude of displacement is maximized in the command signal. The excitation force is reduced at the B phase.

  That is, as shown in FIG. 1, B immediately after the operator operates the operation unit 25 so as to reduce the excitation force to stop the vibration of the vibration target 1 (FIG. 3). A command signal for instantaneously reducing the excitation force is generated at the phase of (refer to), and this command signal is transmitted to the excitation unit 22. Based on this command signal, the excitation unit 22 instantaneously reduces the excitation force at a phase shifted by 90 ° with respect to the phase at which the vibration speed of the vibration target 1 becomes zero. Thereby, when the excitation force applied to the excitation target 1 is reduced, a weak excitation force while the excitation force is being reduced is applied to the excitation target 1, or when the vibration velocity is large. It is possible to reduce that the impact load resulting from the reduction of the excitation force is applied to the excitation object 1. Thereafter, the vibration target 1 performs damping free vibration, and eventually the vibration stops.

  Thus, when the excitation force to be applied to the excitation target 1 is reduced, the magnitude between the command signal for causing the excitation target 1 to vibrate at a predetermined frequency and the response signal of the vibration of the excitation target Since the timing for reducing the excitation force applied to the excitation target 1 is adjusted according to the phase difference, a weak excitation force while the excitation force is being reduced is applied to the excitation target 1, or It is possible to reduce the impact load caused by lowering the excitation force when the vibration speed is high from being applied to the object 1 to be excited.

Next, an operation for the analysis unit 30 to determine the damping vibration characteristic of the vibration target 1 will be described.
As shown in FIG. 1, the analysis unit 30 performs excitation based on the range after the excitation unit stops the vibration of the excitation target in the response signal transmitted from the response signal acquisition unit 23. The damping vibration characteristic of the object 1 is determined. The damping vibration characteristic obtained when the vibration target 1 vibrates at its natural frequency is a damping constant.

  FIG. 4 shows a command signal for stopping the vibration of the vibration target 1 and a response signal when the vibration of the vibration target 1 is stopped. Each of the phases A and B in FIG. 3 is shown in FIG. After the excitation force is reduced so as to stop the vibration of the vibration target 1, that is, immediately after the phase of B, the response signal gradually decreases in amplitude.

In FIG. 4, an attenuation curve connecting the positions A, A ₁ and A _{2 at} which the amplitude of the response signal periodically peaks in the range after the phase of B is drawn by a dashed dotted line. In FIG. 4, the portion of the response signal below the line L where the amplitude of the response signal becomes zero is folded back so as to be positioned above the line L, and the folded portion is drawn by a broken line in FIG. The positions C ₁ , C ₂ and C _{3 at} which the amplitude periodically peaks in the portions drawn by broken lines are also located on the attenuation curve. The analysis unit 30 can determine the damping constant from this damping curve in a known manner.

  When the vibration test apparatus 10 including the vibration apparatus 20 reduces the excitation force to be applied to the excitation object 1, a weak excitation force is applied to the excitation object 1 while the excitation force is being reduced. Because it is possible to reduce that the impact load caused by lowering the excitation force when the vibration velocity is high is applied to the object 1, the damping vibration characteristics of the object 1 are accurately determined. can do.

  As described above, when the vibration device 20 stops the vibration of the vibration target 1, the weak vibration force during the reduction of the vibration force is applied to the vibration target 1, the vibration speed Although it can be reduced that the impact load resulting from the reduction of the excitation force is applied to the excitation object 1 when the vibration force is large, the residual pressure of the excitation device 20 and the inertia of the excitation object 1 Remaining, the excitation force may not be completely zero. FIG. 5 shows an example of the remaining excitation force.

In order to eliminate the influence of such remaining excitation force as much as possible when determining the damping vibration characteristic, as shown in FIG. 4, immediately after the excitation unit 22 stops the vibration of the object 1 to be excited. Is attenuated from a phase curve after phase (A) when the vibration speed of the vibration object 1 becomes zero, that is, from an attenuation curve connecting C ₁ , A ₁ , C ₂ , A ₂ and C _3. Determine the constant. Thereby, it is possible to determine the damping constant while eliminating the influence of the remaining excitation force as much as possible.

  In this embodiment, the operation of reducing the excitation force to zero to stop the vibration of the vibration target 1 has been described, but the present invention is not limited to this mode. Even when the excitation force is reduced to a value larger than zero, that is, when the amplitude of vibration is reduced without stopping the vibration, the above-described operation can be applied.

  In this embodiment, the vibration object 1 is vibrated at its natural frequency, but is not limited to this form. The vibration target 1 can also be vibrated at an arbitrary frequency for which it is desired to evaluate the damping. When the vibration target 1 vibrates at a frequency smaller than the natural frequency, the phase difference between the command signal and the response signal is generally smaller than 90 °, and the vibration target 1 is larger than the natural frequency. When oscillating at a frequency, the phase difference between the command signal and the response signal is generally greater than 90 °.

  In this embodiment, the vibration unit 22 is an inertia-type vibrator, but is not limited to this form. However, in order to determine the damping vibration characteristic by the above method, it is preferable that the excitation unit 22 is an inertia type exciter.

  In this embodiment, the damping vibration characteristic is a damping constant, but is not limited to this form. The damping vibration characteristic may be any index that indicates ease of stopping the vibration, and the analysis method in the analysis unit 30 can be changed according to the type of the damping vibration characteristic.

DESCRIPTION OF SYMBOLS 1 Excitation object 10 Vibration test apparatus 20 Excitation device 21 Signal generation part 22 Excitation part 23 Response signal acquisition part 24 Phase difference detection part 25 Operation part 30 Analysis part

Claims (6)

A signal generation unit that generates a command signal for causing the vibration target to vibrate at a predetermined frequency;
An excitation unit that applies an excitation force to the excitation target based on the command signal;
A response signal acquisition unit that acquires a response signal of the vibration of the vibration target;
A phase difference detection unit that detects a phase difference between the response signal and the command signal;
The excitation unit applies the excitation to be applied to the excitation object according to the phase difference detected by the phase difference detection unit when reducing the excitation force to be applied to the excitation object. An exciter configured to adjust the timing of reducing the shaking force.   The excitation apparatus according to claim 1, wherein the timing is a phase shifted by the phase difference from a phase when the speed of vibration of the excitation object becomes zero in the response signal.   The vibration device according to claim 1 or 2, wherein the predetermined frequency is a natural frequency of the vibration target.   The said vibration part is a vibration apparatus as described in any one of Claims 1-3 which generate | occur | produces the said vibration force with the reaction force which an inertial mass vibrates. The vibration exciter according to claim 4;
A vibration test apparatus, comprising: an analysis unit that determines a damping vibration characteristic of the vibration target based on the response signal after the vibration unit stops the vibration of the vibration target.   In the response signal, based on a phase range after the phase when the vibration speed of the vibration target becomes zero immediately after the vibration unit stops the vibration of the vibration target. The vibration test apparatus according to claim 5, wherein the analysis unit determines the damping vibration characteristic.

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