JPS6055257A - Ultrasonic testing device - Google Patents

Abstract

PURPOSE:To remove a harmful ultrasonic wave signal due to acoustic coupling status monitoring and to attain proper testing by forming transmission pulses for the acoustic coupling status monitoring independently of testing transmission pulses. CONSTITUTION:Ultrasonic wave vibrators 2a, 2b excited by transmission circuits 1a, 1b generate ultrasonic beams and make the beams incident on a material 4. The transmission circuits 1a, 1b have timing exciting the ultrasonic vibrators 2a, 2b simultaneously and timing exciting only the vibrator 2b independently. The vibrators 2a, 2b receive ultrasonic wave signals obtained by reflecting the ultrasonic beams on the surface and the inside of the material 4 and input the received signals to respective receiving circuits 7a, 7b, the outputs of the receiving circuits 7a, 7b are added by an adder 10 and the added result is inputted to a signal processing circuit 8a to discriminate a defect. On the other hand, the output of the circuit 7b is inputted to a signal processing circuit 8b independently to monitor acoustic coupling status or the like. Consequently, a harmful ultrasonic wave signal due to the monitoring of the acoustic coupling status is removed and proper testing using ultrasonic waves can be attained.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an inspection device for inspecting the inside of a material using ultrasonic waves. The present invention provides an effective device for confirming that the ultrasonic waves generated by () are incident (-) into the material.

[Prior Art J Conventionally, the process of confirming that the ultrasonic waves generated by an ultrasonic probe have definitely entered the material is called monitoring the acoustic coupling state, and the method for achieving this is to make sure that the ultrasonic waves are transmitted through the material. or reflected by a reflective source in the material or on the surface of the material,
A detection probe is placed at the position where the ultrasonic wave reaches the surface of the material again, and the magnitude of the ultrasonic signal that arrives is monitored. Methods such as monitoring surface reflection echoes have been adopted. The former method can be adopted if the arrival position when the ultrasonic wave that has been transmitted or reflected through the material reaches a certain surface of the material again is known, but if this arrival position is unknown, this method should be adopted. is extremely difficult. In addition, when ultrasonic waves are incident on one side of a plate-shaped material and the ultrasonic echoes reflected from the other side are monitored, there may be a reflection source in the material that causes the incident ultrasonic waves to return to the same position. Except in certain cases, a generation probe and a monitoring probe are required separately, resulting in a complex structure and high cost. Therefore, the latter method is often adopted. In the latter case, the ultrasonic waves actually incident on the material are not detected, so although it cannot be said to be a perfect method, most of the reasons why the ultrasonic waves entering the material are impaired are due to the interference between the probe and the material. This is because the couplant in between is not properly formed, so if it is confirmed that the ultrasonic waves have reached the surface of the material, it can almost certainly be assumed that the ultrasonic waves have entered the material.

FIG. 1 is a diagram showing an example of the latter method.

In this example, in order to detect welding defects in metals such as iron, ultrasonic waves are applied obliquely to the material, and the reflected echoes that are reflected from the welding defects are detected to detect welding defects. This is an example of the ultrasonic flaw detection method. In the figure (1
) is a transmitting circuit, (2a) is a vibrator for flaw detection, (21
)) is a vibrator for monitoring the acoustic coupling state, (3) is a wedge for sound propagation between the vibrator (2a), (2b) and the material, 14) is the material to be inspected, and (5) is the material ( 4) welded part, (6) the probe, f7) the receiving circuit, (8a)
(8b) is the first signal processing circuit, and (8b) is the second signal processing circuit.

(9a) is a first output circuit, (9b) is a second output circuit.

F is a welding defect in the welded portion (5).

The operation of the conventional example shown in FIG. 1 will be explained.

The ultrasonic transducer (2a) excited by the transmission circuit (1)
).

(2b) generates an ultrasonic beam and injects the ultrasonic beam into the material (4) via the wedge (3) and a couplant (not shown). The ultrasonic beam generated by the vibrator (2a) is obliquely incident on the material (4) and reaches the weld (5). If there is a defect F such as a poor weld in the welding part (5), the ultrasonic wave is reflected by this defect F and returns to the probe (6).
) K is also obtained, so the reflected echo is received by the ultrasonic transducer (2a) and input to the receiving circuit (7). The receiving circuit (7) amplifies the received signal, and the first signal processing circuit (8a) performs signal processing such as defect determination.

The first output circuit (9a) is a circuit that displays and outputs the results.

On the other hand, the ultrasonic beam generated by the transducer (2b) is
), the ultrasonic transducer (
This reflected echo is received by the receiver circuit (7b).
) is entered. The receiving circuit (7) amplifies the received signal,
The second signal processing circuit (8b) performs signal processing such as monitoring the acoustic coupling state, and the second output circuit (9b) is a circuit for displaying and outputting the results.

However, the conventional example shown here has the following problems. That is, the ultrasonic beam generated by the ultrasonic transducer (2b) provided for monitoring the acoustic coupling state is reflected by the bottom surface of the material (4), etc.
(a) Since this is received as a harmful signal, it becomes noise that is the original welding defect signal.

[Summary of the invention]

The present invention has been made in order to improve these conventional drawbacks, and provides an ultrasonic inspection device that monitors the acoustic coupling state so as not to cause harmful noise to the original ultrasonic signal. be.

(Embodiment of the invention) Fig. 2 is a diagram showing an embodiment of the present invention. In the figure, (1a) is a first transmitting circuit, (1b) is a second transmitting circuit, (2a), (2b) ) is an ultrasonic transducer 7 (3) is a wedge.

(4) is the material, (5J is the welded part, (61 is the probe, (7
a) is the first receiving circuit, (7b) is the second receiving circuit,
(8a) is the first signal processing circuit, (8b) is the second signal processing circuit, (9a) is the first output circuit, (9b)
is the second output circuit 1oe is the addition circuit, F is the welding part (5)
Welding is defective. FIG. 3 is a diagram showing the transmitted pulses and received signals of the apparatus shown in FIG. 2. In the figure, A is the transmission pulse waveform applied to the vibrator (2a), B is the transmission pulse waveform applied to the vibrator (2b), and C is the adder circuit Q.
1 is the output waveform, and D is the output waveform of the second receiving circuit (7b).

So is T. , E'ab is the surface echo returned from the surface of material (4) corresponding to Ta and Tb + FQ is T
. To.

'ab is the echo of defect F corresponding to Ta and Tb.

Next, the operation will be explained.

The ultrasonic transducers (2a) and (2b) excited by the first transmitting circuit (1a) and the second transmitting circuit (1b) generate ultrasonic beams, and An ultrasonic beam is incident on the material (4) via the couplant.The oscillators (2a) and (2b) are installed close to each other, and when excited at the same time, they exhibit the same behavior as just one oscillator. Next, in the present invention, the vibrator (
Apart from the timing of exciting 2a) and 2b at the same time, there is a timing of exciting the vibrator (2b) independently.Since the size of the vibrator (2b) is small, it has a wide beam angle and an ultra-high beam angle. An ultrasonic beam with low acoustic energy is generated. Since the directivity angle is wide, sufficient reflected echoes can be obtained even from the surface of the material (4).

Conversely, the ultrasonic beam that enters the material becomes smaller by the amount of vibration. Therefore, it does not become a harmful ultrasonic signal. Now,
The transducer (2a) receives the ultrasonic beams generated by the transducers (2a) and (2b) and returns after being reflected on the material surface and inside the material, and is connected to the first receiving circuit (7a).
is input. Similarly, the ultrasonic signal received by the transducer (2b) is also input to the second receiving circuit (7b). First receiving circuit (7a) and second receiving circuit (7'o)
The outputs are added by an adder circuit Cl11 and inputted to a first signal processing circuit (8a), where signal processing such as defect determination is performed, and the result is outputted by a first output circuit (9a). On the other hand, the output of the second receiving circuit (7b) is inputted alone to the second signal processing circuit (8b), where signal processing such as monitoring of the acoustic coupling state is performed, and the result is sent to the second output circuit (9b).
b) will be issued. That is, as shown in FIGS. 3A and 3B, the excitation pulse T2 for exciting the vibrator (2a) and the excitation pulse Tb for the vibrator (2b) are at the same timing,
In addition to this, there is an excitation pulse Tc that excites only the vibrator (2b), so the input waveform of the first signal processing circuit (8a) is O, D, T5, T. The material surface echo SC corresponding to is small on the transducer (2a) side and large on the transducer (2b) side. Further, the reflected echo from inside the material corresponding to +TO is sufficiently smaller than the reflected echoes produced by T and Tb, and therefore does not become a harmful noise component. In the embodiment of the present invention, To is the predecessor of Tb, but T. Even after Tb, the same effect is exhibited. Moreover, it goes without saying that the effect will be further increased if the strength of To is made smaller than that of Tb. On the other hand, even if adding circuit 4 is omitted, the oscillator (2b
) is sufficiently smaller than the vibrator (2a) or T. but'
A similar effect can be expected by making it sufficiently smaller than rb. or.

It goes without saying that the effects of the present invention can also be applied when the probe (6) is an array probe in which a plurality of transducers are arranged in a play shape. In this case T. Even if there are a plurality of transducers to which transmission is performed, the gist of the present invention is not impaired in any way. In this case, the first transmitting circuit (1a) and the second transmitting circuit (1b) may be composed of a plurality of pieces, or the wiring may be convenient for inspecting the plurality of transducers and monitoring the acoustic coupling state. It goes without saying that the same effect can be obtained even if it is made and used.

In addition, as an embodiment of the present invention, an example was given in which a welded part is detected by ultrasonic flaw detection, but the effects of this invention are not limited to this example, but the effect of this invention is not limited to this example. Applicable to all ultrasonic inspection equipment.

[Effects of the present invention]

As described above, the present invention eliminates harmful ultrasonic signals caused by monitoring the acoustic coupling state by providing a transmitting pulse for monitoring the acoustic coupling state separately from the transmitting pulse for performing the original inspection. , it is possible to conduct a good ultrasound examination.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a conventional ultrasonic inspection apparatus. FIG. 2 is a diagram showing the configuration of the ultrasonic testing apparatus of the present invention. FIG. 3 is a diagram showing the transmitted pulse and received signal of the diagram shown in FIG. 2. In the figure, (I) is a transmitting circuit. (2a), (2b) are oscillators, (3) are wedges, (4
) is material 7 (6) is the probe, (force is the receiving circuit, (8a
), (8b) are signal processing circuits, (9a), (9b
) is the output circuit. Note that the same or corresponding parts in FIG. 9 are designated by the same reference numerals. Agent Masuo Oiwa Figure 1

Claims (1)

[Claims] Ultrasonic transducer having multiple ultrasonic transducers
and one or more first transmitting circuits or a group of transmitting circuits wired to the ultrasonic transducer in a predetermined connection method;
A first receiving circuit or receiving circuit group wired one-to-one with the first transmitting circuit or transmitting circuit group, and signal processing of the output of the first receiving circuit or receiving circuit group to detect the inside of the material using ultrasonic waves. and a first signal processing circuit that inspects and outputs judgment results. a first output circuit that outputs the signal processing result of the first signal processing circuit; and one or more second transmitting circuits or a group of transmitting circuits wired to the ultrasonic transducer in a predetermined connection method. , a second receiving circuit or receiving circuit group wired one-to-one with the second transmitting circuit or transmitting circuit group, and signal processing of the output of the second receiving circuit or receiving circuit group to connect the material and the receiving circuit group. It has a second signal processing circuit that monitors the acoustic coupling state between the ultrasonic transducers and outputs a determination result, and a second output circuit that outputs the signal processing result of the second signal processing circuit. An ultrasonic inspection device characterized by: