JPH0668486B2 - Method for diagnosing peeling on finished surfaces of buildings - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for diagnosing whether or not a tile or a base mortar covering a surface of a building frame is peeled off inside, and particularly a finished surface. When tapping with a tapping tool, the tapping sound attenuation characteristic generated by the tapping is different depending on the presence or absence of peeling, which allows easy, reliable, and quick diagnosis.

[Prior art] Conventionally, as a method of diagnosing peeling of a finished surface of a building, a method based on the volume of a tapping sound when the finished surface is tapped, a method of analyzing its waveform to capture features, and a tapping Known methods include a method using repulsive acceleration generated in a hitting tool, a method using infrared rays, and a method using ultrasonic waves.

[Problems to be solved by the invention]

However, each of these conventional methods has the following problems. That is, in each of the above methods, the depth from the surface of the building is limited to about 20 mm, and if the depth is more than that, the diagnostic accuracy is poor. However, peeling in the deep layer means that the base mortar is peeled off from the body, and if this is left unattended, peeling proceeds easily, and there is a danger that a large-area finished surface will eventually fall to the ground. In this method, it takes 500 ms per point to process the tapping sound and analyze its waveform. In addition, the method of (1) complicates the apparatus and makes its operation difficult, and requires specialized knowledge and experience.

The present invention has been made by paying attention to such conventional problems, and can be easily used without requiring any special knowledge or experience, and is capable of rapid real-time processing, especially 20 mm. It is an object of the present invention to provide a method for diagnosing peeling of a finished surface of a building, which can obtain a highly reliable diagnosis result even in the above deep area diagnosis.

[Means for solving problems]

The present invention which achieves the above object, taps a building finish surface, converts the tapping sound into a tapping sound signal, and uses the integrated value of the time-series signal after the tapping sound signal reaches the maximum level value as a reference. By comparing with the value, the peeling on the finished surface of the building is judged.

[Action]

When the depth of peeling is shallow within 20 mm from the finished surface, the maximum amplitude value of the waveform of the tapping sound is twice or more as compared with that without peeling, and therefore the presence or absence of peeling can be determined only by the maximum amplitude value. However, if the depth of the peeled portion exceeds 20 mm from the finished surface, there is no difference in the maximum amplitude value due to the presence or absence of peeling, and it is difficult to determine.

However, there is a clear difference in the attenuation characteristic of the tapping sound waveform even when peeling occurs in a deep layer of 40 mm or more. For example, FIG. 1 shows an example of a tap sound waveform in a sound tile, FIG. 2 shows that of a peeling tile with a deep layer peeling, and the vertical axis represents the sound pressure level (amplitude) of the tapping sound. The horizontal axis is the time axis with the moment of tapping as zero. As is clear from the figure, the magnitude (amplitude) of the tapping signal is exponentially attenuated with the moment of tapping as the maximum, but the time constant is 0.181 ms in the case of the healthy tile, The tile is 0.593ms, which is very different.

Therefore, according to the present invention, the tapping signal at the moment of tapping, which may be difficult to make a difference depending on the presence or absence of peeling, is removed. As a result, a portion in which the tap sound waveforms with and without peeling are clearly different is extracted, and the maximum signal level value or a value obtained by integrating the time-series signals is used. Thus, the presence / absence of peeling in the deep portion can be surely determined with high accuracy. Moreover, waveform analysis is no longer necessary, and real-time processing is possible with a simple circuit.

〔Example〕

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

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

In the figure, reference numeral 1 is a frame forming an outer wall, an inner wall, a ceiling, a floor, etc. of a building, the surface of which is a finished surface to which tiles 2 are attached via a base mortar. Reference numeral 3 is a diagnostic device for diagnosing the peeling of the tile 2.

The diagnostic device 3 includes a transmitter and a receiver. The transmitting unit transmits a driving signal S ₁ to the driving circuit 5 and a hammer driving circuit 5 having a rotating solenoid for driving the hammer 4 for driving the finishing surface of the tile 2 for rotation, and at the same time as described later. The trigger signal generation circuit 11 and the determination circuit 12 are composed of a drive signal generation circuit 6 for transmitting drive signals S ₂ and S ₃ .

On the other hand, the receiving unit collects the reverberant sound when the finishing surface is tapped and converts it into an electric signal, an amplifier circuit 8 for amplifying the electric signal, and an amplified electric signal which is not suitable for diagnosis. A filter circuit 9 for removing a necessary frequency component (noise), a gate circuit 10 for removing a tap sound component at the moment of tapping from a signal wave component passing 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
Generating circuit 11 for sending a trigger to the gate, and gate circuit 10
The determination circuit 12 that determines the presence or absence of peeling by taking the maximum level value (maximum amplitude value) or integrated value of the time-series signal output from the reference signal, and displays the determination result with a lamp or buzzer. And the display circuit 13.

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

First, the diagnostic device 3 is brought close to the surface of the tile 2 of the device under test, and the start switch (not shown) is turned on. Drive signal generation circuit 6
Generates a drive signal S ₁ and sends it to the hammer drive circuit 5. At the same time, the drive signals S ₂ and S ₃ are also sent to the trigger generation circuit 11 and the determination circuit 12 for timing. In response to the signal S ₁ , the rotary solenoid of the hammer driving circuit 5 is activated, and the hammer 4 for hammering strikes the surface of the tile 2. The sound generated by this striking is collected by the microphone 7, converted into an electric signal according to the sound pressure level, and then the amplifier circuit 8,
The signal is output to the gate circuit 10 and the trigger generation circuit 11 via the filter circuit 9.

That is, the gate circuit 10 receives, for example, a sounding waveform signal of a sound tile as shown in FIG. 4 or a sounding waveform signal of a peeling tile as shown in FIG. Become.

In FIG. 6, the vertical axis represents the passage rate (%), and the horizontal axis represents the time t (ms).
Is an example of the pass characteristic of the gate circuit 10 shown by
This is represented by a characteristic curve that is exactly the opposite of the sounding waveform envelope E of the sound tile shown in FIG.
As a result, most of the sound wave waveform signal components of the sound tile are
It cannot pass through the gate circuit 10.

On the other hand, the trigger generation circuit 11 receives the drive signal S ₂ from the drive signal generation circuit 6 for a predetermined time (a hammer hammer 4 hits the subject, and the sound of the hammer is collected by the microphone 7 for a predetermined time). When the tapping signal from the filter circuit 9 is input within the time until it is output as a signal plus a margin time), the trigger signal S ₄ is output.

Receiving this, the gate circuit 10 opens its gate for a preset predetermined time (for example, 5 ms). For example, when a sounding waveform signal of a sound tile shown in FIG. 4 is input to the gate circuit 10, most of it is blocked. As a result, the passing output signal is as shown in FIG. 7 with the tapping sound component at the moment of tapping removed. Further, for example, when the tapping sound waveform signal of the peeling tile shown in FIG. 5 is input, the tapping sound component at the same tapping time is removed, and only the portion different from the tapping sound waveform of the sound tile passes. That means the eighth
It becomes like the figure.

The judgment circuit 12 samples the output signal from the gate circuit 10 and holds the peak value of the amplitude thereof, and compares this with a preset amplitude reference value. Alternatively, the integral value of the signal is obtained and compared with the integral reference value. As a result of the comparison, if the difference from the reference value is small, it is determined that the finished surface is sound, and if the difference from the reference value is large, it is determined that there is peeling on the finished surface. Here, either the peak value or the integrated value may be taken, and if both are taken, the accuracy becomes higher.

The determination result is output to the display circuit 13 and displayed by a lamp or a buzzer. By the way, in the inspection test of the deep layer having a depth of 40 mm, the time required for diagnosis was only 10 ms per location.

That is, according to this embodiment, the simple gate circuit 10
Since the sounding wave formation portion of the sound tile is erased by, there is no need to perform a complicated waveform analysis as in the past. Further, since the initial tapping sound signal is removed by the gate circuit 10, the presence or absence of peeling of the deep layer can be diagnosed with high accuracy. Further, the diagnosis is started at the same time as the generation of the signal, and the diagnosis is ended at the end of the signal, which enables real-time processing, and the diagnosis can be speeded up.

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

When the inspection of the next tile is started, a new drive signal generation circuit 6
The drive signal is output from the control circuit, but part of the drive signal is sent to the determination circuit 12 as the peak elimination signal S ₃ . As a result, the holding of the amplitude peak value and the integrated value is released to prepare for the next cycle.

According to this embodiment, one of the maximum signal level value of the tapping sound signal excluding the tapping sound at the moment of tapping and the integrated value of the time series signal of the tapping sound excluding the tapping sound at the same moment of tapping Although a method of making a diagnosis by determining the presence or absence of peeling has been described by using, there is also an advantage that the reliability of the diagnosis result becomes particularly high if the diagnosis is made by using both.

The signal passage characteristic of the gate circuit 10 may be as shown in FIG. In this case, the gate is opened all at once after a predetermined delay time td has elapsed after receiving the trigger signal S ₄ from the trigger generation circuit 11. The sound waveform signal of a sound tile output from this gate circuit is as shown in FIG. 10, for example. Further, the sound wave waveform signal of the peeling tile is as shown in FIG. 11, for example.
In either case, the tapping sound at the moment of tapping is removed by the delay time td, and only the portion where the amplitude widths of the two are significantly different can be used for diagnosis. This has the advantage that the gate circuit can be made simpler.

Note that the gate circuit having the pass characteristic shown in FIG. 6 and the gate circuit having the pass characteristic shown in FIG. 9 may be used in combination to switch the inspection location depending on the depth.

Further, in each of the above embodiments, the case where the diagnosis is performed by using both the maximum amplitude value and the integrated value of the tapping sound signal excluding the moment when the tapping is performed simultaneously or separately, is not limited to this.
Both values may be used separately depending on the depth of the inspected portion, for example.

Further, the judgment circuit 12 shown in FIG. 3 may be configured by using a microcomputer.

Further, a CRT can be used as the display means 13.

〔The invention's effect〕

As described above, according to the present invention, the diagnosis is made by using the integrated value of the time-series signal after the tap sound signal obtained by removing the tap sound at the moment of tapping by the gate circuit reaches the maximum level value. Real-time processing is possible and quick diagnosis is possible. Moreover, a highly reliable diagnostic result can be obtained even at a depth of 20 mm or more. In addition, the device for carrying out this method has a simple structure and can be miniaturized, and it can be easily used without requiring special knowledge or experience.

[Brief description of drawings]

FIG. 1 is a graph showing the attenuation characteristics of a sound wave shape of a sound tile, FIG. 2 is a graph showing the attenuation characteristics of a sound wave shape of a peeling tile, and FIG.
4 and 5 are graphs each schematically showing a sounding waveform of a sound tile and a sounding waveform of a peeling tile by the device of FIG. 3, and FIG. 6 is a passage of a gate circuit in the device of FIG. A graph showing an example of the characteristics, FIGS. 7 and 8 are graphs each schematically showing a sounding waveform after passing through the gate circuit. FIG. 7 shows a sound tile, and FIG. 8 shows a peeling tile. Is the case. FIG. 9 is a graph showing another example of the pass characteristics of the gate circuit in the apparatus of FIG. 3, FIG. 10 is a graph showing the sound wave shape of a sound tile passing through the gate circuit, and FIG. 11 is also a peeling tile. 7 is a graph showing a sound wave shape of 3 is a diagnostic device, 4 is a hammer for hammering, 5 is a hammer driving 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] 1. A method for tapping a finish surface of a building, converting the tapping sound into a tapping sound signal, and comparing the integrated value of the time series signal after the tapping sound signal reaches a maximum level value with a reference value. The method for diagnosing peeling of a building finished surface is characterized by determining peeling on the building finished surface.