JPH0448188B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Industrial Field of Application] The present invention relates to an apparatus for inspecting the hemming adhesive filling condition of a machined end of a vehicle body.

[Prior art]

Conventionally, processing edges (hemming) of vehicle bodies
Adhesive filling is performed for the purpose of rust prevention. The method of testing whether the hemming adhesive is sufficiently filled is to fill a test piece with the adhesive and perform a cutting test to estimate the filling state of the adhesive in the product vehicle. A method for inspecting the filling state of an adhesive using ultrasonic waves, and an inspection apparatus therefor are known.

[Problem that the invention seeks to solve]

However, although the cutting test method described above can directly inspect the filling state of adhesive, it is not possible to conduct a cutting test on the actual product. It was only an estimate of the filling state of the adhesive. As a result, it was considered that there were variations in the adhesive filling state at the processed end of the actual vehicle body.

On the other hand, the method of inspecting the filling state of adhesive using ultrasonic waves is a non-destructive test that allows inspection of the processed edges of the actual vehicle body, but since the waveform of the ultrasonic wave is visually observed, it is difficult to check the filling state.・Due to reasons such as difficulty in determining whether or not to use a product or a low S/N ratio, the technology has not yet been finalized. Therefore, the current situation is to rely on the above-mentioned cutting test.

Structure of the Invention [Means for Solving the Problems] The structure adopted by the present invention in order to solve the above problems is as shown in FIG. That is, the hemming adhesive filling state inspection device of the present invention comprises: an ultrasonic wave generating means for emitting ultrasonic waves for a predetermined period of time toward a processed end of a vehicle body where adhesive filling has been performed; an ultrasonic receiving means for receiving reflected waves or transmitted waves of ultrasonic waves from the processed end; and a reference having a predetermined duration corresponding to the received wave when the adhesive filling state of the processed end is normal. a reference wave generating means for generating a wave; a comparison means for comparing a duration of the reference wave with a duration of the received wave; and display means for displaying that the adhesive filling state of the processed end is normal when the duration of the wave is less than the duration of the wave.

Here, the ultrasonic receiving means is for receiving reflected waves or transmitted waves from the processed end, and when receiving reflected waves, the ultrasonic receiving means is used to transmit ultrasonic waves to the processed end. When they are set on the same side and receive transmitted waves, they are set on the opposite side of the processed end to the ultrasonic generation means.

Further, the reference wave may be, for example, a received ultrasonic wave obtained when the adhesive is sufficiently filled in a test using a test piece or the like in advance.

[Effect]

The hemming adhesive filler inspection device of the present invention is constructed as described above and operates as follows.

The ultrasonic generating means emits ultrasonic waves to the processed end of the vehicle filled with adhesive for a predetermined period of time, and the ultrasonic receiving means receives reflected waves or transmitted waves of the ultrasonic waves from the processed end. This received wave has a duration depending on the filling state of the adhesive at the processed end. On the other hand, the reference wave generating means generates a reference wave having a predetermined duration corresponding to the received wave when the adhesive filling state of the processed end is normal, and this reference wave and the received wave by the ultrasonic receiving means When the duration of the received wave is less than the duration of the reference wave, the display means displays that the adhesive filling state of the processed end is normal.

〔Example〕

Next, embodiments of the present invention will be described in detail.

Fig. 1 is a block diagram showing an embodiment of the hemming adhesive filling state inspection device of the present invention, Fig. 2 is a time chart showing waveforms of each part in this embodiment, and Fig. 3 is a clearance diagram also in this embodiment. FIG. 4 is a graph showing the relationship between (layer width) and reflectance/transmittance. Similarly, FIG. 4 is a graph showing an example of received waves in this embodiment.

The hemming adhesive filling state inspection device of this embodiment is constructed as shown in FIG. The processed end portion 1 is composed of a vehicle body material 2, a U-shaped processed end member 3 that covers the vehicle body material 2, and an adhesive 4 filled between these.The adhesive 4 is generally made of rubber. adhesives are used. Ultrasonic waves are emitted from the probe 5 to the processed end 1, and reflected waves 8 from the processed end 1 are also received by the probe 5. The received wave received by the probe 5 is input to the ultrasonic flaw detector 9. The ultrasonic flaw detector 9 is equipped with a CRT 10 so that the received waves can be observed. Furthermore, the analog signal a, which is the output signal of the ultrasonic flaw detector 9, is output to the detection circuit 11. The detection signal b detected by the detection circuit 11 is input to the limiter circuit 12. A reference voltage c is input to the limiter circuit 12,
Using this reference voltage c and the limiter circuit 12, the detected signal b is output as a square wave d. This square wave d
and the clock signal e from the clock generator 13 are input to the AND circuit 14. The AND circuit 14 outputs the clock pulse e when the square wave d is on as a pulse signal f. This pulse signal f and the reference wave generated by the reference wave generation circuit 15 are input to a comparator 16, and based on the comparison result between the duration of the pulse signal f and the duration of the reference wave, a judgment display circuit 17
The determination result of whether the filling state of Adhesive 3 is good or bad is displayed.

Next, the operation of the hemming adhesive filling state inspection device shown in the block diagram of FIG. 1 will be explained using the time chart of FIG. 2.

The received wave input to the probe 5 is sent to the ultrasonic flaw detector 9
The signal is subjected to appropriate waveform processing and output as an analog signal a. This analog signal a is detected by a detection circuit 11 and becomes a detected signal b. The detection signal b is turned on by the limiter circuit 12 when it exceeds the reference voltage c and becomes a square wave d. Next, in the AND circuit 14, the AND of the square wave d and the clock pulse e from the clock generator 13 is taken, and the square wave d
The clock pulse e is extracted only when is on. This signal is the pulse signal f. on the other hand,
The reference wave generation circuit 15 outputs a reference wave having a duration corresponding to the received wave when the filling state of the adhesive is normal, so by comparing this reference wave with the duration of the signal f, the adhesive It is possible to judge whether the filling condition is good or bad.
In this embodiment, when the number of pulses of the signal f is smaller than the number of pulses of the reference wave, the filling state of the adhesive is determined to be normal. The judgment display circuit 1 uses the judgment result of this comparator 16.
7, if the filling state of the adhesive is normal, the "OK" lamp is lit, and if it is abnormal, the "NG" lamp is lit.

Here, the principle of determining whether the adhesive filling state is good or bad will be explained based on the duration of the received wave. Figure 3 shows the relationship between the clearance, which is the distance between the vehicle body material 2 and the processed end member 3, and the reflectance and transmittance when ultrasonic waves with a frequency of 5 MHz are emitted to a stacked structure such as the processed end 1. These are graphs showing the relationship; FIG. 3A is a graph when the adhesive is not filled, and FIG. 3B is a graph when the adhesive is filled.

Ultrasonic waves are attenuated when propagating through the processed end member 3, and also at the interface with the adhesive 4 (when the adhesive 4 is not filled, the interface with air)
shows reflection and transmission. The clearance when the adhesive 4 is not filled is less than 5 μm because the vehicle body material 2 and the processed end member 3 are in close contact with each other, and the reflectance and transmittance at this time are about 80% as seen from Figure 3A. About 20% of ultrasonic waves are transmitted and about 20% are reflected. Conversely, when the adhesive 4 is filled, the clearance is 60 to 80 μm and the reflectance is about 3%. Therefore, even if adhesive is present, most of it will be transmitted as if it were not. However, the rubber adhesive used as the adhesive 4 has an extremely high attenuation rate of ultrasonic waves. Therefore, most of the ultrasound transmitted to the adhesive 4 is attenuated within the adhesive 4 and is received by the probe 5 as a weak ultrasound signal. From the above, ultrasonic waves pass through the interface regardless of the presence or absence of adhesive 4, but when there is no adhesive 4, the attenuation of the ultrasonic wave is small, and when there is adhesive 4, the ultrasonic wave is attenuated rapidly. . Therefore, when an ultrasonic wave with a predetermined energy is emitted to the processed end 1, the ultrasonic wave with stronger energy will be received without the adhesive 4 than with the adhesive 4, and the probe 5
The duration of the received wave received by the receiver becomes longer. Therefore, the filling state of the adhesive 4 at the processed end 1 can be determined based on the duration of multiple echoes of the received waves imaged on the CRT 10 of the ultrasonic flaw detector 9.

FIG. 4 is a graph showing an example of the measurement results of the received waves in FIG. 1 showing this embodiment. Figure 4A
4B shows a case where the filling of the adhesive 4 is normal, and FIG. 4B shows a case where the filling of the adhesive 4 is abnormal. As can be seen from these graphs, the duration of the ultrasonic reception wave is considerably shorter when the filling state of the adhesive 4 is normal than when the filling state is abnormal.

As explained above, according to this embodiment, it is possible to inspect the adhesive filling state of the machined end portion 1 of the vehicle body using ultrasonic waves without cutting it, and also to compare it with a predetermined reference wave. Since it determines whether the adhesive filling state is good or bad, it can be inspected without misreading the waveform of the received ultrasonic wave. Therefore, since the adhesive filling state of all products can be inspected using the same standard, it is possible to take sufficient measures to prevent the products from rusting, and there is also the effect that quality control is further improved.

Although this embodiment uses the ultrasonic flaw detector 9, it is of course possible to simply use the ultrasonic oscillator and the ultrasonic receiver separately.

Effects of the Invention According to the hemming adhesive filling state inspection device of the present invention, the adhesive filling state at the processed end of a vehicle can be inspected without cutting, and the received ultrasonic wave is compared with a predetermined reference wave. Since the determination is made using Therefore, the adhesive filling condition of all products can be inspected using the same standards.
There is also the effect that rust prevention measures for products can be sufficiently implemented, and product quality control can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Fig. 2 is a time chart showing the waveforms of various parts in this example, Figs. 3 A and B are graphs showing the relationship between the clearance and reflectance/transmittance of the processed end of this example, respectively, and Fig. 4 Similarly, A and B each represent a graph showing an example of received waves in this embodiment. DESCRIPTION OF SYMBOLS 1... Processing end part, 5... Probe, 9... Ultrasonic flaw detector, 11... Detection circuit, 12... Limiter circuit, 13
...Clock generator, 14...AND circuit, 15...Reference wave generation circuit, 16...Comparator, 17...Judgment display circuit.

Claims (1)

[Scope of Claims] 1. Ultrasonic generation means for emitting ultrasonic waves for a predetermined period of time toward a processed end of a vehicle body where adhesive filling has been performed; and a reference wave generating means that generates a reference wave having a predetermined duration corresponding to the received wave when the adhesive filling state of the processed end is normal. and a comparison means for comparing the duration of the reference wave and the duration of the received wave, and based on the comparison result of the comparison means, the duration of the received wave is less than the duration of the reference wave. A hemming adhesive filling state inspection device comprising: display means for displaying that the adhesive filling state of the processed end portion is normal when the hemming adhesive filling state is normal.