JPH0440325A - Vibration measuring method and vibration meter - Google Patents

Abstract

PURPOSE:To accurately measure the vibration state of a body to be measured by detecting a shift in the phase of a reflected wave which is caused by the vibration of the body to be measured. CONSTITUTION:The high frequency wave oscillated by a high frequency oscillator 1 is outputted to an ultrasonic wave transmitter 4 only when the rectangular wave from a rectangular wave oscillator 3 is inputted through an AND circuit 2. The high frequency wave from the oscillator 1 is therefore parted by the circuit 2 and outputted intermittently. The parted high frequency wave is passed through an amplifier 5 and converted by a converter 6 into an ultrasonic wave, which is oscillated intermittently to the body O to be measured. The ultrasonic wave which is reflected by the body O to be measured is converted by the converter 8 of an ultrasonic wave receiver 7 into an electric signal, which is amplified by an amplifier 9 and inputted to a phase detector 10. The detector 10 detects the phase of the reflected wave to extract an electric signal corresponding to the vibration state of the body O to be measured and the demodulated electric signal is inputted to a vibration detector 11. The detector 11 corrects the density of liquid propagating a carrier and detects the vibration state of the body to be measured.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a vibration IJ that detects vibrations of an object to be measured such as a machine.
J11111 relates to vibration measurement methods and vibration resistance, and particularly relates to non-contact vibration measurement methods that can detect vibrations without touching the object to be measured, and to improvements in vibration resistance.

[Conventional technology]

Vibration R1, which detects the vibration of the object to be measured, has conventionally come in two types: contact type and non-contact type. Of these, the contact type does not require the hassle of attaching a sensor to the object to be measured. This required a lot of work, and the work efficiency was poor.

On the other hand, various types of non-contact vibration meters have been known, such as capacitor type, eddy current type, and optical type.

[Problem to be solved by the invention]

By the way, among the non-contact type vibration meters mentioned above, the capacitor type and eddy current type have a measurable distance of several days.
Since the number of vibrations is about 1, it is necessary to install a vibration meter close to the object to be measured, but it is not possible to install a vibration meter in the surrounding conditions of the object to be measured, making it difficult to detect vibrations. It was obvious that it couldn't be done.

Also, with the optical type mentioned above, the measurable distance is several 1
Although it is long at 0 m, it is complicated because the target must be glued to the object to be measured, and there is also the problem that the detection results are affected by the color of the target, resulting in low accuracy of the detection results.

The present invention overcomes the problems with the conventional methods and provides a non-contact vibration measurement method and vibration set that can accurately detect the vibration state of an object without requiring complicated work. The purpose is to

[Means to solve the problem]

In order to achieve the above-mentioned object, the vibration measurement method according to the present invention transmits ultrasonic waves of a constant frequency to an object to be measured, receives a reflected wave whose phase is modulated by the vibration of the object as a carrier wave, and It is characterized by detecting the phase of the carrier wave and detecting the vibration state of the object to be measured.

The vibration meter according to the present invention also includes a high-frequency oscillator that oscillates high-frequency waves, and an ultrasonic transmitter connected to the high-frequency oscillator that converts the high-frequency waves oscillated from the high-frequency oscillator into ultrasonic waves and transmits the ultrasonic waves to the object to be measured. an ultrasonic receiver that receives a reflected wave of the transmitted wave whose phase is modulated by the vibration of the object to be measured;
It consists of a phase detector that detects the phase change of the reflected wave received by this ultrasonic receiver, and a vibration detector that detects vibration of the object to be measured based on the output signal of this phase detector.

Furthermore, the vibration detector can be configured to compensate for the density of the fluid that propagates the carrier wave.

[For production]

According to the vibration measuring method and vibration meter of the present invention having the above-described configuration, when the high frequency generated in the high frequency oscillator is converted into ultrasonic waves of a constant frequency by the ultrasonic transmitter and then transmitted toward the object to be measured, this When the transmitted wave is reflected from the measured object, the reflected wave from the measured object returns, but the phase of this reflected wave changes as the distance between the transmitter and the reflected position of the measured object changes. It turns out. Therefore, when the object to be measured vibrates, the phase of the reflected wave changes constantly, so this phase-modulated reflected wave is received by an ultrasonic receiver, and the phase of the reflected wave is detected by a phase detector. By detecting it, the state of vibration of the object to be measured can be measured.

Further, by configuring the vibration detector to be able to correct the density of the fluid that propagates the carrier wave, temperature correction can be performed and the state of vibration of the object to be measured can be measured more accurately.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vibration measuring method and vibration meter according to the present invention will be explained below with reference to embodiments shown in the drawings.

The figure does not show an embodiment of the vibration generator according to the present invention, and in the figure, reference numeral 1 indicates a high frequency oscillator. This high frequency oscillator 1 is connected to an AND circuit 2 for making the high frequency oscillated by the 8-frequency oscillator 1 intermittent. signals are also input.

Note that this AND circuit 2 may specifically be an analog switch.

The high frequency which has passed through the AND circuit 2 and has been rendered intermittent is input to an ultrasonic transmitter 4.

This ultrasonic transmitter ff1i4 is composed of an amplifier 5 that amplifies the input high frequency wave, and a converter 6 that converts the amplified high frequency wave into an ultrasonic wave and transmits it to the object to be measured O in the direction G. .

On the other hand, an ultrasonic receiver A7 is provided for receiving the reflected waves of the ultrasonic waves transmitted from the ultrasonic transmitter 4 toward the object to be measured and reflected by the object to be measured. The ultrasonic receiver 7 includes a converter 8 that receives a reflected wave and converts it into a high frequency wave, and an amplifier 9 that amplifies the high frequency wave converted by the converter 8. Note that the converter 8 is equipped with a resonant microphone to ensure that only reflected waves are received.

A phase detector 10 is connected to the amplifier 9 of the ultrasonic receiver 7, and the phase detector 10 detects the phase of the reflected wave received by the ultrasonic receiver 7. Note that this phase detector 10 is similar to the rectangular wave oscillator 3.
It is also connected.

Further, a vibration detector 11 is connected to the phase detector 10, and the vibration state of the object to be measured 0 can be detected by the vibration detector 11 based on the phase of the reflected wave detected by the phase detector 10. It has become.

Note that the vibration detector 11 is configured to correct the density of the fluid that propagates the carrier wave.

Next, a vibration measuring method of the present invention using the vibration meter of the present embodiment having the above-described configuration will be explained.

To measure vibrations of an object to be measured O such as a machine (not shown), an ultrasonic transmitter 4 and an amplifier 5 are directed to a specific position of the object to be measured. Then, by operating an operation means such as an operation button (not shown), the high frequency oscillator 1 continuously oscillates high frequency waves. The high frequency wave oscillated from the high frequency oscillator 1 is input to the AND circuit 2, and the AND circuit 2 outputs the high frequency wave from the high frequency oscillator 1 to the ultrasonic transmitter 21i4 only when the rectangular wave from the square wave oscillator 3 is input. As a result, the high frequency from the high frequency oscillator 1 is divided in the AND circuit 2 and output intermittently. The power of this divided high frequency wave is amplified by the amplifier 5 of the ultrasonic transmitter 4, and then converted into ultrasonic waves by the converter 6, which transmits the waves intermittently toward the object to be measured. be done. Then, this transmitted wave is reflected on the surface of the object to be measured, and this reflected wave returns toward the receiver 6.

By the way, when the object to be measured O is vibrating, the distance from the transmitter 5 to the reflection site of the object to be measured constantly changes, so the phase of the reflected wave changes constantly.

When a sound wave from a stationary sound source (transducer 6 of the ultrasonic transmitter 4) is reflected on a vibrating surface that is a reflective surface on the surface of the object to be measured O, the distance between the sound source and the reflecting surface will depend on the amplitude of the vibrating surface. It will change accordingly. Therefore, the reflected wave causes a change in phase corresponding to the amplitude according to the vibration period (frequency) of the vibration surface. By using this principle, the vibration state (frequency, amplitude, velocity, acceleration) of the object to be measured O can be measured at a position away from the object to be measured.

Therefore, the ultrasonic wave as the reflected wave is received by the converter 8 of the ultrasonic receiver 7, the received reflected wave is converted into an electrical signal, and then the reflected wave is amplified by the amplifier 9. Next, this amplified reflected wave is input to the phase detector N10 to perform phase detection of the reflected wave to extract an electrical signal corresponding to the vibration state of the object to be measured O. Next, the electrical signal adjusted by the phase detector 10 is input to the vibration detector 11, and the density of the fluid propagating the carrier wave is corrected based on the frequency, amplitude, etc. of this electrical signal, and the temperature is adjusted to the measurement band. After eliminating the negative effects, the frequency of the object to be measured O,
Vibration conditions such as amplitude can be detected.

According to the embodiment described above, the ultrasonic wave from the ultrasonic transmitter 4 is transmitted to the object to be measured O, and the reflected wave, which has been phase-modulated in accordance with the vibration state of the object to be measured, is transmitted to the ultrasonic receiver 7. By receiving the signal from α1 and detecting its phase by the phase detector 10, and checking this demodulated waveform by the vibration detector 11, the vibration state of the object to be measured O can be detected without contacting the constant object 0 at all. . Therefore, the vibration state of the object to be measured O in the cylinder can be detected without requiring complicated work.

In addition, the ultrasonic waves transmitted to the object to be measured O are directional, so they can be transmitted and received efficiently.Furthermore, due to the directional nature of the ultrasonic waves, they are not only convenient as carrier waves for general main vibration waves. , it is possible to increase the resolution Vi degree for detecting an abnormal vibration location of the object to be measured O. moreover,
Ultrasound can be easily separated from m-sound in the general environment, so
By using a resonant microphone for the ultrasonic receiver 7, it is possible to completely cut out noise and perform vibration measurement with good accuracy. Furthermore, since the ultrasonic wave has a short wavelength, the resolution for detecting the phase difference caused by the vibration of the object to be measured O is high.

In this manner, according to this embodiment, the vibration state of the object to be measured 0 is measured by transmitting ultrasonic waves to the object to be measured 0, so that the vibration state can be measured with extremely high accuracy. According to this embodiment, since the ultrasonic waves are intermittently transmitted from the ultrasonic transmitter 4 using the AND circuit 2 or the like, deformation of the waveform of the reflected waves due to interference between the reflected waves and the transmitted waves can be prevented. It is possible to prevent vibrations from occurring and ensure stable vibration tying.

The present invention is not limited to the embodiments described above,
Various changes can be made as necessary.

For example, the vibration measurement method and vibration meter according to the present invention include:
It can be used not only in air but also in various liquids and gases.

(Effects of the Invention) As explained above, according to the vibration measurement method and vibration meter according to the present invention, by detecting the phase change of the reflected wave caused by the vibration of the object to be measured, it is possible to perform a non-contact and complicated work. This provides an excellent effect in that the vibration state of the object to be detected can be measured with high precision without the need for such a method.

[Brief explanation of the drawing]

The figure is a circuit diagram showing an embodiment of a vibration meter according to the present invention. 1...High frequency oscillator, 2...AND circuit, 3...
Square wave oscillator, 4... Ultrasonic transmitter, 5... Amplifier, 6... Variable 1 & 7... Ultrasonic receiver, 8...
Converter, 9... Multiplier, 10... Phase detector, 11
...Vibration detector, 0...Object to be measured.

Claims (1)

[Claims] 1) Transmitting ultrasonic waves of a constant frequency to an object to be measured, receiving a reflected wave whose phase is modulated by the vibration of the object as a carrier wave, and detecting the phase of the received carrier wave, A vibration measurement method characterized by detecting the vibration state of an object to be measured. 2) A high-frequency oscillator that oscillates high-frequency waves; an ultrasonic transmitter that is connected to the high-frequency oscillator and converts the high-frequency waves oscillated from the high-frequency oscillator into ultrasonic waves and transmits them to the object to be measured; an ultrasonic receiver that receives a phase-modulated reflected wave of the transmitted wave; a phase detector that detects a phase change in the reflected wave received by the ultrasonic receiver; A vibration meter consisting of a vibration detector that detects the vibration of the object to be measured. 3) The vibration meter according to claim 2, wherein the vibration detector is configured to correct the density of the fluid that propagates the carrier wave.