JPS63168555A - Diagnosis of separation for finished surface of building - Google Patents

Abstract

PURPOSE:To obtain results of diagnosis with a high reliability, by comparing with a reference value at least one of the max. level value of a tapping sound signal excluding the value as given the moment a finished surface is tapped and an integral value of time-sequence signals of tapping sounds excluding the one as given the moment tapping is made. CONSTITUTION:A diagnosing device 3 is brought closer to the surface of a tile 2 as object to be tested and a start switch is turned ON. A driving signal generation circuit 6 generates driving signals S1-S3. Receiving the signal S1, a rotary solenoid of a hammer driving circuit 5 operates and a tapping hammer 4 taps the surface of the a tile 2. Echoes are gathered with a microphone 7 and supplied to a gate circuit 10 and a trigger generation circuit 11 via an amplification circuit 8 and a filter circuit 9. When a signal is inputted from the circuit 9 within an assumed fixed time from the reception of the signal S2, the circuit 11 outputs a trigger signal S4. The circuit 10 opens the gate for a preset specified time to pass components alone differing from a tapping sound waveform of a sound tile. A judging circuit 12 compares an output of the circuit 10 with a reference value, thereby enabling the diagnosing of separation at a high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for diagnosing whether or not tiles or base mortar covering the surface of a building frame are peeling off inside, and in particular, the present invention relates to a method for diagnosing whether tiles or base mortar covering the surface of a building frame are peeling off inside. Diagnosis can be easily, reliably, and quickly made by taking advantage of the fact that, when struck with a striking tool, the magnitude of the echo sound generated by the striking and its attenuation characteristics differ depending on the presence or absence of peeling.

[Conventional technology]

Conventionally, the methods for diagnosing peeling of the finished surface of a building include: ■ A method based on the magnitude of the reverberating sound when the finished surface is tapped; ■ A method that captures the characteristics of the waveform of the reverberant sound; ■ A method that uses a tapping tool when the finished surface is tapped. The following methods are known: (1) a method using infrared rays, (2) a method using ultrasonic waves, etc.

[Problem that the invention seeks to solve]

However, each of these conventional methods has the following problems. In other words, ■ above.

For each method (2) and (2), the depth from the building surface is limited to about 20 fins, and the diagnostic accuracy deteriorates at deeper depths. However, peeling in the deep layer means that the base mortar has peeled off from the structure, so if this is left untreated, the peeling will easily progress and there is a risk that a large area of the finished surface will eventually fall to the ground. In method (2), it takes 500 ms per point to process the echo sound and analyze its waveform. In addition, methods ① and ③ require complicated equipment;
Its operation is also difficult and requires specialized knowledge and experience.

This invention was made by focusing on these conventional problems, and is easy to use without requiring special knowledge or experience, and is capable of rapid real-time processing, especially for 20 m ■A method for diagnosing peeling on finished surfaces of buildings that provides highly reliable diagnostic results even when diagnosing the above-mentioned deep parts! It is intended to provide.

[Means for Solving the Problems] The present invention, which achieves the above object, taps the finished surface of a building, converts the echo sound of the tap into a tap sound signal, and then detects the tap excluding the moment of the tap. Peeling on the finished surface of the building is determined by comparing at least one of the highest level value of the sound signal and the integral value of the time-series signal of the tapping sound excluding the moment of hitting with a reference value.

[Effect]

If the depth of the peeling is shallow, within 20 degrees from the top surface, the maximum amplitude value of the waveform of the hitting reverberation sound is more than twice that of one without peeling, so it can be determined whether there is peeling or not based only on the maximum amplitude value. I can judge. However, the depth of the peeled area is 20 mm from the finished surface.
When m1 is exceeded, there is no difference in the maximum amplitude value depending on the presence or absence of peeling, making it difficult to determine.

However, regarding the attenuation characteristic of the waveform of the hitting echo sound, 40
There is a clear difference even when peeling occurs at a depth of mm or more. For example, No. 1M shows an example of the hammering sound waveform in a healthy tile, and Figure 2 shows that of a peeling tile with peeling in the deep layer, and the vertical axis represents the sound pressure level (amplitude) of the hitting sound. The horizontal axis is the time axis with the moment of hitting as zero.

As is clear from the figure, the size and amplitude of the tapping sound signal are
It decays exponentially with the moment of hitting being the maximum,
The time constant for the healthy tile is 0°181 m5, while for the peeled tile it is 0.593 m5, which is a large difference between the two.

Therefore, the present invention eliminates the tapping sound signal at the moment of hitting, in which it is difficult to distinguish between the presence or absence of peeling. As a result, a portion where the hitting sound waveforms with and without peeling are clearly different is extracted, and the highest signal level value or the value obtained by integrating the time series signal is used. In this way, the presence or absence of peeling in deep areas can be diagnosed with high precision and reliability. Furthermore, there is no need for waveform analysis, and real-time processing is now possible with a simple circuit.

〔Example〕

Embodiments of the invention will be described below with reference to the drawings.

FIG. 3 shows an embodiment of a diagnostic device for carrying out the method of diagnosing peeling on a finished surface of a building according to the present invention.

In the figure, 1 is the outer wall, inner wall, and ceiling of the building.

It is a frame that forms a floor, etc., and its surface is a finished surface with tiles 2 pasted through a base mortar. 3 is a diagnostic device for diagnosing peeling of the tile 2.

This diagnostic device 3 includes a transmitter and a receiver. The transmitter includes a hammer 4 that hits the finished surface of the tile 2, and a hammer drive [! iJ I! 'r5, and a drive signal Sl is sent to this drive circuit 5, and at the same time, drive signals S2 and S3 are sent to a trigger generation circuit 11 and a judgment circuit 12, which will be described later.
It consists of a drive signal generation circuit 6 that transmits.

On the other hand, the receiving section includes a microphone 7 that collects the reverberant sound when hitting a finished surface and converts it into an electrical signal, an amplifier circuit 8 that amplifies the electrical signal, and a diagnostic test using the amplified electrical signal. A filter circuit 9 that removes necessary frequency components (noise), a gate circuit 10 that removes the component of the hitting sound at the moment of hitting from the signal wave component that has passed through the filter circuit 9, and the drive signal generating circuit 6. and when receiving the output signal of the filter circuit 9, the gate circuit 10
a trigger generation circuit 11 that sends a trigger to the gate circuit 10;
A judgment circuit 12 takes the highest level value (maximum amplitude value) and integral value of the time-series signal output from and compares it with a reference value to determine the presence or absence of peeling, and displays the judgment result with a lamp or buzzer. It is composed of a display circuit 13.

A method for diagnosing the presence or absence of peeling on the finished surface of a building using the above device will be explained.

First, the diagnostic device 3 is brought close to the surface of the tile 2 of the test object and a starting switch (not shown) is turned on. Drive signal generation circuit 6
generates a drive signal S1 and sends it to the hammer drive circuit 5. At the same time, drive signals S2 and 83 are also sent to the trigger generation circuit 11 and determination circuit 12 in order to obtain timing. In response to the signal S, the rotary solenoid of the hammer drive circuit 5 is activated, and the striking hammer 4 strikes the surface of the tile 2. The sound generated by this impact is reflected by the tile surface of the subject, the interface between the tile and the mortar, the interface between the mortar and the building frame, and the like. After the reflected sound is collected by a microphone 7 and converted into an electrical signal according to the sound pressure level, an amplifier circuit 8. Gate circuit 10 and trigger generation circuit 11 via filter circuit 9
Output to.

That is, the gate circuit 10 receives, for example, a hammering waveform signal of a sound tile as shown in FIG. 4, or a hammering waveform signal of a peeling tile as shown in FIG. 5, which has a different attenuation characteristic. Become.

Figure 6 shows the passage rate (%) on the vertical axis and time t (ms) on the vertical axis.
This is an example of the passage characteristic of the gate circuit 10 shown by taking
The envelope E of the sound waveform of a sound tile shown in FIG. 4 is expressed by a characteristic curve that is the opposite of the curve.

As a result, most of the striking waveform signal components of healthy tiles are
It cannot pass through the gate circuit IO.

On the other hand, after receiving the drive signal S2 from the drive signal generation circuit 6, the trigger generation circuit 11 generates an electric signal for a predetermined period of time (the hammer 4 hits the subject, the echo sound is collected by the microphone 7, and an electric signal is generated). When the signal from the filter circuit 9 is input within the time (time required for outputting the trigger signal S4 plus the margin time), the trigger signal S4 is output.

Upon receiving this, the gate circuit 10 opens the gate for a predetermined period of time (for example, 5 ms). If, for example, the sound waveform signal of a healthy tile shown in FIG. 4 is input to the gate circuit 10, most of the waves are blocked.

As a result, the passing output signal becomes as shown in FIG. 7, with the hitting sound component at the moment of hitting removed. For example, if the hammering waveform signal of the peelable tile shown in Fig. 5 is manually generated,
Similarly, the hitting sound component at the moment of hitting is removed, and only the part that is different from the hitting sound waveform of a healthy tile passes through, resulting in a result as shown in Fig. 8.

The judgment circuit I2 samples the output signal from the gate circuit 10, holds the peak value of its amplitude, and compares it with a pre-adjusted amplitude reference value. At the same time, an integral value of the sampled signal is obtained and compared with an integral reference value. As a result of the comparison, if both the differences from the reference values are small, it is determined that the finished surface is sound, and if both the differences from the reference values are large, it is determined that there is peeling on the finished surface.

The determination result is output to the display circuit 13 and displayed by a lamp, buzzer, or the like. By the way, in the deep layer inspection test at a depth of 49 ts, the time required for diagnosis was only 10 ms per location.

That is, according to this embodiment, the simple gate circuit 10
This eliminates the impact waveform components of healthy tiles, so there is no need to perform complex waveform analysis as in the past. Furthermore, since the initial tapping sound signal is removed by the gate circuit 10, the presence or absence of peeling in the deep layer can be diagnosed with high accuracy. Furthermore, real-time processing is possible, in which diagnosis is started at the same time as the signal is generated, and the diagnosis is finished when the signal ends, thereby speeding up the diagnosis.

Therefore, the presence or absence of peeling can be easily, quickly, and reliably determined using a simple circuit.

When the next tile is inspected, a new drive signal generation circuit 6 is installed.
A drive signal is output from the drive signal, and a part of it is sent to the judgment circuit 12 as a peak cancellation signal S.

As a result, the holding of the amplitude peak value and the integral value is released and preparation is made for the next cycle.

According to this embodiment, both the highest signal level value of the tapping sound signal excluding the tapping sound at the moment of tapping and the integral value of the time-series signal of the tapping sound excluding the tapping sound at the moment of tapping are used. Since the diagnosis is made by determining the presence or absence of peeling, there is also the advantage that the reliability of the diagnosis result is particularly high.

Note that the signal passing characteristics of the gate circuit 10 described above may be as shown in FIG. 9. In this case, the gate is fully opened at once after a predetermined delay time td has elapsed after receiving the trigger signal S4 from the trigger generation circuit 11. The striking waveform signal of a healthy tile output from this gate circuit is as shown in FIG. 10, for example. Further, the striking waveform signal of the peelable tile is as shown in FIG. 11, for example. In both cases, the delay time td eliminates the tapping sound at the moment of tapping, and only the portion where the amplitude values of the two are significantly different can be used for diagnosis. According to this, there is an advantage that the gate circuit can be made simpler.

Note that the gate circuit exhibiting the passage characteristic shown in FIG. 6 and the gate circuit exhibiting the passage characteristic shown in FIG. 9 may be used together and switched depending on the depth of the inspected location.

Further, in each of the above embodiments, a case has been described in which diagnosis is performed by simultaneously using both the maximum amplitude value and the integral value of the tapping sound signal excluding the moment of hitting, but the present invention is not limited to this. For example, they may be used differently depending on the depth and shallowness of the area to be inspected.

Furthermore, the determination circuit 12 shown in FIG. 3 may be constructed using a microcomputer.

Furthermore, as the display means 13, it is also possible to use a CRT.

[Effects of the Invention] As explained above, according to the present invention, diagnosis is made using the tapping sound signal from which the tapping sound at the moment of tapping is removed by the gate circuit, so real-time processing is possible and rapid processing is possible. Diagnosis possible. Furthermore, highly reliable diagnostic results can be obtained even at depths of 201 m or more. Moreover, the apparatus for carrying out this method has a simple structure, can be made compact, and can be easily used without requiring special knowledge or experience.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the attenuation characteristics of the striking sound waveform of a sound tile, FIG. 2 is a graph showing the attenuation characteristic of the striking sound waveform of a peeled-off tile, FIG. 3 is a block diagram of an apparatus for implementing the present invention, and FIG. Figure 5 is a graph schematically showing the sound waveform of a sound tile and a sound waveform of a peeling tile produced by the apparatus shown in Fig. 3, respectively, and Fig. 6 is a graph showing the passage characteristics of the gate circuit in the apparatus shown in Fig. 3. Graphs showing an example, Figures 7 and 8 are graphs schematically showing the striking waveforms after passing through the same gate circuit, respectively. Figure 7 is for a healthy tile, and Figure 8 is for a peeling tile. It is. Fig. 9 is a graph showing another example of the passage characteristics of the gate circuit in the device shown in Fig. 3, Fig. 1O is a graph showing the striking waveform of a healthy tile that has passed through the gate circuit, and Fig. 11 is a graph showing another example of the passing characteristics of the gate circuit in the device shown in Fig. 3. It is a graph showing a striking sound waveform of. 3 is a diagnostic device, 4 is a hammer, 5 is a hammer drive circuit,
6 is a drive signal generation circuit, 7 is a microphone, 8 is an amplifier circuit, 9 is a filter circuit, 10 is a gate circuit, 11 is a trigger generation circuit, 12 is a judgment circuit, and 13 is a display circuit.

Claims (1)

[Claims] The finished surface of the building is tapped, the echo sound of the tapping is converted into a tapping sound signal, and then the highest level value of the tapping sound signal excluding the moment of hitting and the time series signal of the tapping sound excluding the moment of hitting are calculated. A method for diagnosing peeling of a finished surface of a building, wherein peeling on the finished surface of the building is determined by comparing at least one of an integral value and a reference value.