JP7405393B2 - Vibration test equipment and its failure prediction method - Google Patents

Description

The present invention relates to a vibration testing device for conducting vibration characteristic tests and durability tests of industrial products such as aerospace equipment, automobile equipment, electronic products, and precision equipment, and more specifically, the present invention relates to a vibration testing device that has a failure prediction function. This invention relates to a vibration testing device and a failure prediction method for the vibration testing device.

2. Description of the Related Art Conventionally, vibration tests have been conducted using a vibration test apparatus in order to conduct vibration characteristic tests, durability tests, etc. of industrial products such as aerospace equipment, automobile equipment, electronic products, and precision equipment.

For example, as disclosed in Patent Documents 1 and 2, a vibration test device includes a movable part on which a test object is placed and a fixed part having a magnetic path member, and a static magnetic field generated in the fixed part. The structure is configured to cause the movable part to vibrate by passing an alternating current through the drive coil of the movable part so as to be orthogonal to the movable part.

Further, the vibration testing apparatus is configured to prevent the movable part from vibrating in a direction other than a desired direction by supporting the movable part with a spring or restraining the shaft of the movable part with a constraint bearing.

Further, an AC power source for passing an alternating current through the drive coil of the movable part, and when an exciting coil is used in the magnetic path member, a direct current power source for passing a direct current through the exciting coil are also provided.

Such vibration testing equipment is generally configured to automatically stop for safety purposes in the event of a failure or the like. However, since the vibration test takes a long time depending on the type of the test object, it is an event that the user would like to avoid if a failure occurs during the vibration test and the vibration test is stopped midway.

Therefore, in order to prevent vibration test equipment from malfunctioning, it is necessary to periodically replace parts, perform routine maintenance, or prevent abnormal operation or noise from occurring during preliminary tests conducted before the actual vibration test. By checking to see if there are any abnormalities in the vibration testing equipment.

Japanese Patent Application Publication No. 11-44606 Japanese Patent Application Publication No. 2014-74612 Japanese Patent Application Publication No. 2005-62097

However, if you rely only on the user's senses to check for abnormal operations or noises, you may miss the abnormalities.
For this reason, Patent Document 3 proposes a configuration in which an abnormal state is determined by acquiring the transfer characteristic of a movable part and comparing this transfer characteristic with reference transfer characteristic data stored in advance. ing.

By making an abnormality determination based on the transfer characteristics in this way, it is possible to determine whether there is a failure in the movable part. It is difficult to isolate and detect abnormalities that occur in springs, restraint bearings, etc.).

In addition, if a moving part or excitation coil breaks down, it may take a long time to arrange parts and replace it, so it is important to discover abnormalities early and prepare for replacement work before the vibration test equipment becomes unusable. It is desirable to include it in

In view of the current situation, the present invention provides a vibration testing device and a method for predicting failure of the vibration testing device, which have a failure prediction function to detect abnormalities in the vibration testing device at an early stage and prevent the failure from expanding. With the goal.

The present invention was invented to solve the problems in the prior art as described above, and the vibration test device of the present invention has the following features:
a movable part on which the test object is mounted;
A vibration testing device comprising a magnetic path member having magnetic permeability and a fixed part having a magnetic flux generating means for generating magnetic flux flowing in the magnetic path member,
a three-axis sensor that measures at least one of acceleration, velocity, and displacement of the movable part;
further comprising a calculation device that predicts a failure of the vibration testing device based on the output from the three-axis sensor,
The arithmetic device is
The crosstalk of the movable part is measured based on the output from the three-axis sensor, and the failure prediction is performed based on the magnitude of the amplitude of the crosstalk.

In this type of vibration test equipment,
The arithmetic device is
Measuring at least one of a displacement amount and a vibration frequency of the movable part based on an output from the three-axis sensor, and performing the failure prediction based on at least one of the displacement amount and vibration frequency of the movable part. I can do it.

Further, the arithmetic device may include:
An excitation force coefficient can be calculated based on the output from the three-axis sensor, and the failure prediction can be performed based on the excitation force coefficient.

Such vibration test equipment is
The movable part includes a drive coil,
The drive coil may be configured to receive a vibration signal necessary for applying a predetermined pattern of vibration to the test object from a vibration control device.

In this case, the arithmetic device is
The frequency response of the vibration testing device is measured based on the vibration signal and the output from the three-axis sensor, the resonance frequency of the frequency response is calculated, and the failure prediction is performed based on the resonance frequency. You can do it like this.

In this type of vibration test equipment,
The arithmetic device may be configured to issue an alarm when a failure of the vibration testing device is predicted.
In this type of vibration test equipment,
further comprising a movable part suspension spring that holds the movable part in a movable state,
The three-axis sensor may be arranged vertically above the movable part suspension spring.
Moreover, the three-axis sensor can be arranged at a position other than the surface on which the test object is placed in the movable part.
In this case, it is preferable that the three-axis sensor is disposed on a side surface of the movable part closer to the surface on which the test object is placed.

Moreover, the failure prediction method of the vibration test device of the present invention is as follows:
a movable part on which the test object is mounted;
A failure prediction method for a vibration testing device comprising a magnetic path member having magnetic permeability and a fixed part having a magnetic flux generating means for generating magnetic flux flowing in the magnetic path member, the method comprising:
The crosstalk of the movable part is measured using a three-axis sensor , and the failure prediction is performed based on the magnitude of the amplitude of the crosstalk.

In such a failure prediction method, at least one of the displacement amount and the vibration frequency of the movable part is measured, and the failure prediction can be performed based on at least one of the displacement amount and the vibration frequency of the movable part. .

Further, it is possible to calculate the excitation force coefficient and perform the failure prediction based on the excitation force coefficient.

Further, the frequency response of the vibration test device is measured from the vibration signal input to the drive coil of the movable part and the amplitude of the movable part, the resonance frequency of the frequency response is calculated, and the resonance frequency is calculated based on the resonance frequency. Accordingly, the failure prediction can be performed.
In this type of failure prediction method,
The three-axis sensor may be arranged vertically above a movable part suspension spring that holds the movable part in a movable state.
Further, the three-axis sensor can be arranged at a position other than the surface on which the test object is placed in the movable part.
In this case, it is preferable that the three-axis sensor is arranged on a side surface of the movable part closer to the surface on which the test object is placed..

According to the present invention, failures can be automatically predicted by a calculation device based on the output from the movable part sensor installed in the movable part. can be prevented.

In addition, since it is possible to isolate and diagnose abnormalities in vibration testing equipment using moving part sensors and other sensors, abnormalities in vibration testing equipment can be discovered early and users can can prompt repair work such as parts replacement.

FIG. 1 is a schematic diagram showing an embodiment of the vibration testing apparatus of the present invention.

Hereinafter, embodiments (examples) of the present invention will be described in more detail based on the drawings.
FIG. 1 is a schematic diagram showing an embodiment of the vibration testing apparatus of the present invention.
As shown in FIG. 1, the vibration testing apparatus 10 of this embodiment includes a fixed part 11 having a magnetic path member 16, etc., and a movable part 30 on which a test object (not shown) is mounted. .

The fixed portion 11 includes a magnetic path member 16 made of a magnetically permeable material such as iron, and an excitation coil 14 (magnetic flux generating means) that generates a magnetic flux flowing through the magnetic path member 16. The excitation coil 14 sends a constant magnetic flux through the magnetic path member 16 by applying a DC voltage from a constant voltage source (not shown), and is orthogonal to the drive coil 36 inserted into the gap 24 of the magnetic path member 16. The magnetic field is arranged so as to generate a magnetic field (static magnetic field).

The movable section 30 includes a test stand 33 on which a test object (not shown) is placed, a movable section suspension spring 34 that connects the movable section 30 and the fixed section 11 and holds the movable section 30 in a movable state. A drive coil 36 is provided at the bottom of the movable portion 30 to be inserted into the gap 24 of the magnetic path member 16.

The drive coil 36 is connected to a vibration control device 48 via a power amplifier 46, and a vibration signal necessary for applying a predetermined pattern of vibration to the test object is sent from the vibration control device 48 via the power amplifier 46. It is configured so that it can be done.

Furthermore, the movable part 30 has a shaft (restriction shaft 39) that is inserted into the bearing 22 provided on the fixed part 11. The bearing 22 is provided with a restraint bearing 42, and the restraint shaft 39 of the movable part 30 is restrained by the restraint bearing 42.
The movable part 30 has its movable range in the horizontal and vertical directions limited to a predetermined range by a restraint mechanism having a shaft (restriction shaft 39), a bearing 22, a restraint bearing 42, and the above-mentioned movable part suspension spring 34. ing.

Further, as a restraint mechanism, a damper (not shown) may be provided between the fixed part 11 and the movable part 30. By providing the damper in this manner, it is possible to prevent damage to the movable part 30 from being applied to the movable part 30 with an excitation force that is more than necessary.

Note that the restraint mechanism may include all of the mechanisms described above, or may include only some of the mechanisms, and the type of restraint mechanism may be changed as appropriate depending on the specifications of the vibration testing device 10. I can do it.

In this embodiment, the excitation coil 14 is configured to generate a static magnetic field, but a permanent magnet may be provided instead of the excitation coil 14. Further, in order to prevent the vibration testing apparatus 10 from malfunctioning due to heat generated by passing current through the excitation coil 14 and the drive coil 36, it is preferable to provide a cooling means such as air cooling or water cooling.

In the vibration testing apparatus 10 of this embodiment configured as described above, the movable part 30 is provided with a three-axis sensor 31 as a movable part sensor. The three-axis sensor 31 is capable of measuring at least one of acceleration, velocity, and displacement in the X-axis direction, which corresponds to the vibration direction of the movable part 30, and in the Y-axis direction and Z-axis direction, which are perpendicular to the X-axis. be.

In this embodiment, since the movable part 30 vibrates in one direction, this is made to match the X-axis direction, but if the movable part 30 vibrates in two directions, for example, The three-axis sensor 31 can be provided on the movable part 30 so that the three-axis sensor 31 is aligned with the X-axis direction and the Y-axis direction.

The three-axis sensor 31 is connected to a calculation device 50 such as a computer, and the calculation device 50 is configured to predict failures of the vibration testing device 10 based on the output of the three-axis sensor 31.

Note that, as the arithmetic device 50, for example, a personal computer, a microcontroller, etc. can be used, and it can also be incorporated into the vibration control device of the vibration testing device 10.

The arithmetic device 50 predicts a failure of the vibration testing device 10 in the following manner.
(1) Crosstalk Measurement Based on the output of the three-axis sensor 31, crosstalk, which is vibration that occurs on an excitation axis of the vibration testing apparatus 10, that is, in this embodiment, other than the X axis, is detected. In this embodiment, vibrations in the Y-axis direction and vibrations in the Z-axis direction constitute crosstalk.

Crosstalk occurs to some extent due to so-called mechanical play, but in particular, crosstalk becomes large due to failure or severe wear and tear of the restraint mechanism.
The computing device 50 is configured to issue an alarm when the amplitude of the detected crosstalk becomes larger than a predetermined amplitude threshold set in advance. The alarm may be displayed on a display means, for example, or may be notified by a sound such as a buzzer.

In this way, by measuring crosstalk using the 3-axis sensor 31, it is possible to detect wear and tear on the restraint mechanism, and to issue a warning to the user and replace the restraint mechanism before the restraint mechanism fails. etc. can be encouraged.

(2) Displacement measurement Based on the output of the three-axis sensor 31, the amount of displacement and frequency of vibration are detected as the displacement of the movable part 30.
The displacement of the movable part 30 changes due to wear and tear of the restraining mechanism, particularly the spring 34 for suspending the movable part.

The arithmetic device 50 calculates when the detected displacement amount of the movable portion 30 becomes larger than a predetermined displacement threshold value set in advance, or when the detected frequency of the movable portion 30 exceeds a predetermined displacement amount threshold value set in advance. The device is configured to issue an alarm when the frequency becomes less than a threshold value.

In this way, by measuring the displacement of the movable part 30 using the 3-axis sensor 31, it is possible to detect the wear and tear of the restraint mechanism, especially the spring 34 for suspending the movable part, and to prevent the restraint mechanism from breaking down. It can issue a warning to the user and prompt them to replace the restraint mechanism.

Note that in this embodiment, the displacement of the movable part 30 is detected using the three-axis sensor 31, but a displacement sensor (not shown) separate from the three-axis sensor 31 is provided to detect the displacement. You can also do that.

(3) Measurement of excitation force coefficient Based on the output of the three-axis sensor 31, the excitation force coefficient of the movable part 30 is calculated as shown in equation (1) below.

Generally, as the current applied to the drive coil 36 increases, the acceleration increases. However, if the drive coil 36 or the excitation coil 14 breaks down or is severely worn out, the acceleration will decrease even if the same current is passed through the drive coil 36.

The calculation device 50 is configured to issue an alarm when the calculated excitation force coefficient becomes smaller than a predetermined excitation force coefficient threshold set in advance.

In this way, by measuring the excitation force coefficient using the 3-axis sensor 31, wear and tear on the drive coil 36 and excitation coil 14 can be detected, and before the drive coil 36 and excitation coil 14 break down, It is possible to issue a warning to the user and prompt the user to replace the drive coil 36 and the excitation coil 14.

(4) Transfer characteristic measurement Based on the vibration signal input from the vibration control device to the vibration test device 10 and the output of the 3-axis sensor 31 (amplitude of the movable part 30), the transfer characteristic (frequency response) of the vibration test device is measured. , calculate its resonant frequency.

The resonant frequency is unique depending on the configuration of the vibration testing apparatus 10, but it changes due to failure or severe wear and tear of the drive coil 36, restraint mechanism, etc.
The arithmetic device 50 is configured to issue an alarm when the calculated resonance frequency becomes smaller than a preset resonance frequency threshold.

In this way, the resonance frequency is calculated by measuring the transfer characteristics, and wear and tear on the drive coil 36, restraint mechanism, etc. can be detected based on this resonance frequency, and before the drive coil 36 or the restraint mechanism breaks down, It is possible to issue a warning to the user and prompt the user to replace the drive coil 36 or the restraint mechanism.

In the present embodiment described above, at least one of acceleration, velocity, and displacement in each axis direction is measured using the 3-axis sensor 31, but it is not limited to the 3-axis sensor 31. For example, three 1-axis sensors may be used. Alternatively, a single-axis sensor can be installed in the required axial direction for measurement.

In addition to failure prediction, for example, by providing a thermal sensor such as a thermocouple in the drive coil 36 and measuring the temperature of the drive coil 36, failure prevention can be performed by the arithmetic unit 50 based on this temperature. can.

(5) Measurement of temperature of drive coil The temperature of the drive coil 36 is measured based on the output of the thermal sensor.
Since the drive coil 36 is fixed to the movable part 30 with an adhesive or the like, if the temperature of the drive coil 36 becomes too high, the adhesive deteriorates and the drive coil 36 becomes loose.

The computing device 50 is configured to issue an alarm when the temperature of the drive coil 36 becomes greater than a preset limit temperature threshold. The limiting temperature threshold value can be set as appropriate depending on the specifications of the vibration testing device 10, the type of adhesive, etc., and can be set to, for example, 90°C to 200°C.

In this way, by taking measures for failure prevention as well as failure prediction, it is possible to provide the vibration testing apparatus 10 in which failures are less likely to occur.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto. For example, in the above embodiments, a thermal sensor is provided for failure prevention, but the present invention is not limited to this. Various modifications can be made without departing from the purpose of the present invention, such as taking various measures to prevent failures.

10 Vibration test device 11 Fixed part 14 Excitation coil 16 Magnetic path member 22 Bearing 24 Gap part 30 Movable part 31 3-axis sensor 33 Test stand 34 Movable part suspension spring 36 Drive coil 39 Restraint shaft 42 Restraint bearing 46 Power amplifier 48 Vibration control Device 50 Arithmetic device

Claims (16)

a movable part on which the test object is mounted;
A vibration testing device comprising a magnetic path member having magnetic permeability and a fixed part having a magnetic flux generating means for generating magnetic flux flowing in the magnetic path member,
a three-axis sensor that measures at least one of acceleration, velocity, and displacement of the movable part;
further comprising a calculation device that predicts a failure of the vibration testing device based on the output from the three-axis sensor,
The arithmetic device is
A vibration testing device characterized in that crosstalk of the movable part is measured based on the output from the three-axis sensor, and the failure prediction is performed based on the magnitude of the amplitude of the crosstalk. The arithmetic device is
Measuring at least one of a displacement amount and a vibration frequency of the movable part based on an output from the three-axis sensor, and performing the failure prediction based on at least one of the displacement amount and vibration frequency of the movable part. The vibration testing device according to claim 1, characterized in that: The arithmetic device is
The vibration testing apparatus according to claim 1 or 2, wherein an excitation force coefficient is calculated based on the output from the three-axis sensor, and the failure prediction is performed based on the excitation force coefficient. The movable part includes a drive coil,
4. The driving coil according to claim 1, wherein the driving coil is configured to receive a vibration signal necessary for applying a predetermined pattern of vibration to the test object from a vibration control device. Vibration test equipment as described. The arithmetic device is
The frequency response of the vibration testing device is measured based on the vibration signal and the output from the three-axis sensor, the resonance frequency of the frequency response is calculated, and the failure prediction is performed based on the resonance frequency. The vibration testing device according to claim 4, characterized in that: The vibration testing device according to any one of claims 1 to 5, wherein the arithmetic device is configured to issue an alarm when a failure of the vibration testing device is predicted. further comprising a movable part suspension spring that holds the movable part in a movable state,
The vibration testing apparatus according to any one of claims 1 to 6, wherein the three-axis sensor is arranged vertically above the movable part suspension spring.. The vibration testing apparatus according to any one of claims 1 to 7, wherein the three-axis sensor is arranged in a position other than a surface on which the test object is placed in the movable part. 9. The vibration testing apparatus according to claim 8, wherein the three-axis sensor is disposed on a side surface of the movable part closer to the surface on which the test object is placed . a movable part on which the test object is mounted;
A failure prediction method for a vibration testing device comprising a magnetic path member having magnetic permeability and a fixed part having a magnetic flux generating means for generating magnetic flux flowing in the magnetic path member, the method comprising:
A failure prediction method, characterized in that crosstalk of the movable part is measured using a three-axis sensor , and failure prediction is performed based on the magnitude of the amplitude of the crosstalk. 11. The method according to claim 10 , wherein at least one of a displacement amount and a vibration frequency of the movable part is measured, and the failure prediction is performed based on at least one of the displacement amount and the vibration frequency of the movable part. Failure prediction method. 12. The failure prediction method according to claim 10 , wherein an excitation force coefficient is calculated and the failure prediction is performed based on the excitation force coefficient. Measure the frequency response of the vibration testing device from the vibration signal input to the drive coil of the movable part and the amplitude of the movable part, calculate the resonance frequency of the frequency response, and based on the resonance frequency, The failure prediction method according to any one of claims 10 to 12 , characterized in that the failure prediction is performed. 14. The failure prediction method according to claim 10, wherein the three-axis sensor is arranged vertically above a movable part suspension spring that holds the movable part in a movable state. The failure prediction method according to any one of claims 10 to 14, wherein the three-axis sensor is arranged in a position other than a surface on which the test object is placed in the movable part. 16. The failure prediction method according to claim 15, wherein the three-axis sensor is disposed on a side surface of the movable part closer to the surface on which the test object is placed .

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