JPH0447245A - Measuring device of impact sound - Google Patents

Abstract

PURPOSE:To enable execution of accurate measurement by taking out a signal of a true impact sound by subtracting a noise signal recorded in a recording means from a collected sound signal obtained from a microphone of a measuring element. CONSTITUTION:When an instruction on an air hammer operation is outputted to an air hammer controller 200 from a signal processing circuit 214, an air hammer 114 is rotated by an operation of an air cylinder 111 and strikes a stator wedge, and a signal of an impact sound generated thereby is inputted to a subtraction circuit 213 through a gate circuit 211. Then an output instruction is given to a noise recording circuit 212 from the circuit 214 and a noise signal recorded just before the strike is inputted to the circuit 213, while a subtraction instruction is inputted to the circuit 213 simultaneously. In this circuit 213, accordingly, the noise signal is subtracted from the impact sound signal to determine only a true impact sound signal, which is inputted to the circuit 214. When the true impact sound signal is taken in from the circuit 213, the circuit 214 subjects the signal to a frequency analysis, measures thereby a state of fixation of a substance to be measured, determine the presence or absence of abnormality and outputs the result to an output element 220.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a hammering sound measuring device that measures the fixing state of an object to be measured, etc. from the hammering sound waveform of the object.

(Prior art) Conventionally, in order to measure the fixed state of an object to be measured, such as the coil pressing state of a wedge that presses a coil inserted into a slot of a stator core of a rotating electric machine, an acceleration sensor is attached to the measurement point. The fixed state was determined by measuring the height of the resonance frequency when attached or pressed and hitting the area with a hammer, and based on the characteristics of the waveform.

(Problem to be Solved by the Invention) However, in such measurement means for fixing the object to be measured, the acceleration sensor is attached or pressed to the measurement point of the object to be measured, so Not only does it have a negative effect on the fixation state, but it also makes it impossible to measure accurately, requires time and effort to attach the acceleration sensor, and requires a mechanism to press the acceleration sensor, which causes problems such as the measuring device itself becoming larger. there were.

An object of the present invention is to provide a hammering sound measuring device that enables accurate measurement without adversely affecting the fixation state of the object to be measured, and that can be made smaller by simplifying the mechanism of the measuring section itself. shall be.

[Structure of the Invention] In order to achieve the above-mentioned object, the present invention includes a hammer 1 mechanism that hits the measuring part of the measured quantity/object with a constant force and speed, and a hammer mechanism that collects the hammering sound generated by the hitting of this hammer mechanism. A measuring section having a built-in microphone, a recording means for measuring and recording noise in the surrounding environment of the object to be measured, and a noise signal recorded in the recording means being subtracted from a collected sound signal obtained from the microphone of the measuring section to obtain a true value. and a signal processing means for analyzing the output signal of the subtraction means and measuring the β1 foot portion to determine the presence or absence of an abnormality.

(Function) In a hammering sound measuring device having such a configuration, when the hammer mechanism built in the measurement unit collects the hammering sound when the object to be measured is hit in a non-contact manner with the microphone, the hammering sound is detected. Since the noise signal of the surrounding environment recorded in the recording means at that time is removed from the signal by the subtraction means and the true hammering sound signal is input to the signal processing means, the true hammering sound signal is analyzed by this signal processing means. As a result, it is possible to easily and accurately measure the fixed state of the object to be measured, and to determine whether there is any abnormality.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is an external view showing a configuration example of a hitting sound measuring device according to the present invention, Fig. 2 is a view of Fig. 1 viewed from the direction of the arrow ■, and Fig. 3 is a view taken along the line FIG. 2 is a configuration diagram showing a measuring instrument main body and its control system in longitudinal section.

As shown in FIG. 1, the tapping sound measuring device of this embodiment is comprised of a measuring device main body 100 and a support portion 300 of the measuring device main body 100. As shown in FIG. 2, the measuring instrument body 100 includes a striking mechanism 110 and a small microphone 120 built into a case 101, and elastic sound-insulating bags stored in bag storage areas formed around the opening of the case 101. 130-133. Impact mechanism 1
10, as shown in FIG. 3, an air cylinder 111, a joint part 112 that moves back and forth while sliding on a pedestal 113 by the air cylinder 111, and a bottle 1 on the pedestal 113.
15, and an air hammer 114 rotatably supported by an air hammer 114. In this case, the air hammer 114 has a guide groove unit 17 for converting the back and forth movement of the bin 116 into rotation.
is provided, and a pin 112 attached to the joint portion 112 is engaged with this guide groove 117. Therefore, the back and forth movement of the joint portion 112 is converted into rotational motion by the pin 116 and the guide groove 117 of the air hammer 114, so that the air hammer 114 rotates around the pin 115.

Further, the support portion 300 is connected to a frame 32 as shown in FIG.
0 and supported on this frame 320, the measuring instrument main body 1
00, and magnetic clamps 330 attached to both ends of a frame 320.

On the other hand, as shown in FIG. 3, the control system that controls the measuring instrument body 100 includes an air hammer controller 200 that controls the air cylinder 111, and an A/D that converts the collected sound signal of the small microphone 120 from an analog signal to a digital signal. A converter 210, a gate circuit 211 that switches and outputs the signal output from the A/D converter 210 at the timing immediately before and after the air hammer 114 operates, and one output end of the gate circuit 211 that outputs the signal output from the air hammer 114. A noise recording circuit 212 temporarily records the noise signal collected by the microphone 120 immediately before the gate circuit 211 operates, and a noise recording circuit 212 temporarily records the noise signal collected by the microphone 120 immediately before the air hammer 114 operates from the other output end of the gate circuit 211. A subtraction circuit 21 receives the noise signal recorded in the signal and noise recording circuit 212 and subtracts the noise signal from the impact signal.
3, and a signal processing circuit 2 that analyzes the frequency of the output signal from the subtraction circuit 213 and measures and determines the fixation state of the object to be measured.
14, an output section 22o5 that outputs the measurement results of the signal processing circuit 214, and a sound insulation bag controller 230 that controls expansion and contraction of the sound insulation bag.

The signal processing circuit 214 has the function of outputting a gate switching command to the gate circuit 211, an air hammer operation command to the air hammer controller 200, and data rewriting and reading commands to the noise recording circuit 212. .

Next, the operation of the hitting sound measuring device configured as described above will be described.

As shown in FIG. 4, the object to be measured is a stator wedge 420 that holds down a coil 410 of a stator 400 of a rotating electric machine.
To explain the case of measuring the tightening state of
It is fixed to the stator 400 using a magnetic clamp 330.

In addition, as shown in FIG. 3, the sound insulation bag controller 23
Air is sent into the sound insulation bags 130 to 133 from 0 to inflate them, and these sound insulation bags 130 to 133 are attached to the stator 40.
0 to prevent noise from entering from around the measuring section.

In such a state, the signal processing circuit 2 shown in FIG.
14 to the gate circuit 211, the noise signal collected by the small microphone 120 is converted into a digital signal by the A/D converter 210, and is output from one output terminal of the gate circuit 211. The noise recording circuit 212 is manually operated. At this time, the signal processing circuit 21
4, a data rewriting command is input to the noise recording circuit 212, and the noise signal sent from the gate circuit 211 is recorded.

Immediately thereafter, an air hammer operation command is issued from the signal processing circuit 214 to the air hammer controller 200, and at the same time, a switching command from one output terminal to the other output terminal is issued to the gate circuit 211. Then, the air hammer 114 rotates due to the operation of the air cylinder 111 and hits the stator wedge 420, and the sound of the impact is collected by the small microphone 120, and the impact sound signal is transmitted to the A/D converter 210 and the gate circuit 211. The signal is input to the subtraction circuit 213 through the subtraction circuit 213.

Here, an output command is issued from the signal processing circuit 214 to the noise recording circuit 212, and the noise signal recorded immediately before the impact is input to the subtraction circuit 213, and at the same time, a subtraction command is input to the subtraction circuit 213. . Therefore, the subtraction circuit 213 subtracts the noise signal from the impact sound signal to obtain only the true impact sound signal, which is input to the signal processing circuit 214.

When the signal processing circuit 214 receives the true impact sound signal from the subtraction circuit 213, it performs frequency analysis on the signal, measures the fixation state of the object, determines whether there is an abnormality, and outputs the result to the output section. 220.

In this case, the signal processing circuit 214 measures and determines the fixation state of the object by comparing it with normal data prepared in advance and checking whether the value is within an allowable range. It will be done.

As described above, in the hammering sound measuring device according to the above embodiment, the elastic sound insulating bags 1 are stored in the bag storage portions formed around the opening of the case 101 of the measuring device main body 100.
By inflating 30 to 133 to surround the outer periphery of the measuring instrument and bringing it into close contact with the surface of the object to be measured, it is possible to almost eliminate noise transmitted through the air, allowing for non-contact quantitative measurement even in noisy environments. It is possible to measure and judge the fixed state. Furthermore, since the microphone is in a non-contact state with respect to the object to be measured, the object to be contacted can vibrate freely, and the electrical noise that has reached the microphone 120 is removed from the impact sound by the subtraction circuit 213. The fixing state of an object can be accurately measured using the microphone 120. Furthermore, in this embodiment, the structure is such that only the impact mechanism 110 and the small microphone 120 are built into the case 101, so unlike the conventional method in which the acceleration sensor is pressed against the object to be measured for measurement, the sensor is pressed and fixed. There is no need for a mechanism for this, and the main body of the meter can be made smaller accordingly. Therefore, when measuring a wedge that holds down the coil of a stator of a rotating electrical machine as an object to be measured, the measuring instrument body must be inserted into the narrow gap between the stator and rotor, but the measuring instrument body must be made smaller. This has the great effect of eliminating interference with the surroundings.

In the above embodiment, the elastic sound-insulating bags 13 are stored in the bag storage areas around the opening of the case 101.
Sound insulation controller 230 every time 0 to 133 is measured.
However, if the sound insulation bag is installed by hand, there is no need to expand or contract the sound insulation bag, and it may be used in an inflated state. In this case, the sound insulating bag may be made of cushion material.

Further, in the above embodiment, the support part 300 is configured such that the guide rail 310 is attached to the frame 320 for measurement; However, it may also be configured to include a built-in moving mechanism that automatically moves the measuring instrument main body 100 to a predetermined position.

[Effects of the Invention] As described above, according to the present invention, accurate measurement is possible without adversely affecting the fixed state of the object to be measured, and the mechanism of the measurement unit itself is simplified and miniaturized. We can provide a hitting sound measuring device that can measure the sound of hitting.

[Brief explanation of the drawing]

Fig. 1 is an external view showing one embodiment of the hitting sound measuring device according to the present invention, Fig. 2 is a view of Fig. 1 viewed from the direction of the arrow ■, and Fig. 3 is a view taken along the line FIG. 4 is an explanatory diagram showing the measuring instrument main body and its control system taken in longitudinal section in the same embodiment when measuring the tightening state of a stator wedge that presses the stator coil of a rotating electric machine. be. 100... Measuring instrument body, 110... Impact mechanism, 111... Air cylinder, 112...
...Joint part, 113...Case, 114...
...Air hammer, 115°116...Bin,
117... Guide groove, 120... Small microphone, 130-133... Sound insulation bag,
200... Air hammer controller, 210.
...A/D converter, 211...Gate circuit, 212...Noise recording circuit, 213...
...Subtraction circuit, 214...Signal processing circuit, 22
0... Output section, 230... Sound insulation bag controller, 300... Support section, 310...
...Guide rail, 320...Frame,
330...Magnetic clamp. lI&1 Figure 2 Ward

Claims (1)

[Claims] A hammer mechanism that hits the measurement part of the object to be measured with a constant force and speed, a measurement unit that has a built-in microphone that collects the impact sound generated by the impact of the hammer mechanism, and measures and records the noise in the surrounding environment of the object to be measured. a recording means for subtracting a noise signal recorded in the recording means from a sound collection signal obtained from a microphone of the measuring section to obtain a signal of a true impact sound, and an output signal of the subtraction means is analyzed. and a signal processing means for measuring the measuring section and determining the presence or absence of an abnormality.