JP5821881B2 - Ultrasonic flaw detection apparatus and ultrasonic flaw detection method - Google Patents

Description

  The present invention relates to an ultrasonic flaw detection apparatus and an ultrasonic flaw detection method that are installed in a continuous production line and perform nondestructive inspection of internal defects to be inspected by ultrasonic waves.

  As an ultrasonic flaw detection apparatus that performs nondestructive inspection of internal defects of a product (for example, a steel plate) that is an object to be inspected using ultrasonic waves, a device as shown in FIG. 8 is known (for example, Patent Document 1). ). The ultrasonic flaw detection apparatus 100 includes a detection unit 101, a signal processing unit 102, a setting / editing unit 103, and a display / operation unit 104. The detection unit 101 includes a transmission probe 105 and a reception probe 106 that are ultrasonic probes (flaw detection probes). As shown in FIG. 9A, the transmission probe 105 and the reception probe 106 are arranged to face each other with a steel plate 107 to be inspected therebetween, and a line focus ultrasonic beam is transmitted from the transmission probe 105 toward the steel plate 107 almost vertically. Transmitted to the steel plate 107 and transmitted to the receiving probe 106 side, and the reflected wave reflected from the internal defect after being incident is received by the receiving probe 106 as an echo signal (flaw detection signal) and received. An internal defect is detected from the flaw detection signal. In FIG. 9A, reference numeral 108 denotes a transmission beam, and 109 denotes a reception beam.

  As shown in FIG. 9B, for the transmitted wave, the primary transmitted wave T1 that reaches the receiving probe 106 after reciprocating 0.5 times in the steel plate 107 and the receiving probe 106 that reciprocates 1.5 times through the steel plate 107. There is a secondary transmitted wave T2 that arrives. When the internal defect exists, as shown in the reception waveform of FIG. 10, the reception probe 106 receives the reflected waves F1 and F2 from the internal defect between the transmitted waves T1 and T2. As a signal processing method at that time, a method of detecting a reflected wave signal (reflected wave F2 in the case of FIG. 10) exceeding the threshold within a predetermined defect gate of the received flaw detection signal as an internal defect is frequently used. Yes.

  However, since the flaw detection signal received by the reception probe 106 includes noise, it is difficult to obtain a high S / N ratio and it may be impossible to detect a small-sized defect.

  For this reason, many techniques have been proposed for improving the level of ultrasonic flaw detection using a signal processing technique that can reduce the influence of noise and obtain a high S / N ratio.

JP-A-7-253414

  Such a signal processing system using signal processing technology that can improve the level of ultrasonic flaw detection is not problematic because it can be directly introduced into the ultrasonic flaw detection apparatus when a new ultrasonic flaw detection apparatus is introduced. In the case of an ultrasonic flaw detector that is already in operation, there are the following problems when only the signal processing system is updated.

1) Even if the new signal processing system itself improves the flaw detection performance, when applied to an existing ultrasonic flaw detector, it cannot be determined that the effect will be the same as the original target. In some cases, the flaw detection performance is lower than that of the existing signal processing system.
2) In order to avoid the above problems, a method of flaw detection by switching between an existing signal processing system and a new signal processing system can be considered only during online testing. Cannot be guaranteed and will adversely affect production.
3) In order to avoid this, a method of newly installing an ultrasonic flaw detector employing a new signal processing system can be considered in addition to the existing ultrasonic flaw detector, but there is a demerit that the cost increases.

  The present invention has been made in view of such circumstances, and can be updated to a level-up signal processing system capable of improving flaw detection performance without adversely affecting production and increasing costs. An object is to provide an ultrasonic flaw detection apparatus and an ultrasonic flaw detection method.

  In order to solve the above problems, the present invention provides an ultrasonic flaw detection apparatus for inspecting an internal defect of a product, which is installed in a continuous line for continuously conveying the product, and which transmits an ultrasonic beam to the product. And a detection unit having a receiving probe for receiving a flaw detection signal based on an internal defect of the product, a signal processing unit for signal processing of the flaw detection signal from the detection unit, and a defect based on the flaw detection signal processed by the signal processing unit A defect editing unit that performs editing, a display unit that displays a flaw detection result based on an editing result by the defect editing unit, and a setting unit that performs presetting of the signal processing unit, the signal processing unit from the detection unit For the output flaw detection signal, the existing signal processing based on the existing signal processing system and the level-up signal processing based on the new signal processing system with improved flaw detection performance are performed in parallel. The flaw editing unit and the display unit edit and display the respective flaw detection signals by these two signal processing, and the setting unit outputs the output in the existing signal processing and the level-up signal processing. An ultrasonic flaw detector is provided that sets a gain value of each signal processing determined by performing a calibration process for matching the outputs in the above.

  In the ultrasonic flaw detection apparatus, the calibration process can be performed by a method of performing a flaw detection process on a calibration plate and determining a gain value so that an output of an existing signal process and an output of a level-up signal process become set values. .

  The signal processing unit includes an existing signal processing board that performs existing signal processing and a level-up signal processing board that performs level-up signal processing, and an input of a flaw detection signal to the level-up signal processing board includes the existing signal It can be carried out via a processing substrate.

  The present invention also transmits an ultrasonic beam from a transmission probe to a product continuously conveyed on a continuous line, receives a flaw detection signal based on an internal defect of the product with a reception probe, and performs signal processing on the received flaw detection signal. An ultrasonic flaw detection method that edits a defect based on a signal-processed flaw detection signal and displays a flaw detection result based on the flaw detection signal, wherein the signal processing is based on an existing signal processing system and flaw detection performance. Is operated in parallel with level-up signal processing based on a new signal processing system whose level has been improved, and each flaw detection signal by these two signal processings is edited and displayed, and the output in the existing signal processing and the level-up Perform calibration processing to match the output in signal processing, determine the gain value of each signal processing, and determine It was set the gain value to provide an ultrasonic flaw detection method characterized by performing ultrasonic flaw detection.

  In the ultrasonic flaw detection method, the calibration process can be performed by a method of performing a flaw detection process on a calibration plate and determining a gain value so that an output of an existing signal process and an output of a level-up signal process become set values. .

  According to the present invention, an existing signal processing based on an existing signal processing system and a level-up signal processing based on a new signal processing system with improved flaw detection performance are operated in parallel with respect to a flaw detection signal output from a detection unit. In addition, the output of these signal processes can be combined. Therefore, it is possible to update to a level-up signal processing system capable of improving the flaw detection performance without adversely affecting production and increasing the cost.

1 is a block diagram showing an ultrasonic flaw detector according to an embodiment of the present invention. It is a figure for demonstrating the dispersion | variation in the output to a level-up signal processing board | substrate in the structure which has a some probe and several existing signal processing board | substrate. It is a figure which shows an example of the output (echo height) when a calibration board is flaw-detected. It is a figure for demonstrating the method of setting a gain value by a calibration process. It is a flowchart of a calibration process. It is a figure for demonstrating operation and the gain setting in the case of a calibration process. It is a figure which shows the result of having actually performed the flaw detection process using the existing signal processing board | substrate and the level-up signal processing board | substrate. It is a block diagram which shows the structural example of the conventional ultrasonic flaw detector. (A) is a figure which shows the transmission probe and reception probe of the detection part in the conventional ultrasonic flaw detector, (b) is a figure for demonstrating the transmitted wave and reflected wave which a reception probe receives. It is a figure which shows the example of the received waveform of a receiving probe.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an ultrasonic flaw detector according to an embodiment of the present invention.

  As shown in FIG. 1, the ultrasonic flaw detector 10 is a non-destructive inspection for an internal defect of a product (for example, a steel plate) that is installed in a continuous line and continuously conveyed, and includes a detection unit 11, a signal processing unit 12, It comprises a setting / editing unit 13 and a display / operation unit 14.

  The detection unit 11 is basically configured similarly to the conventional ultrasonic flaw detector shown in FIG. That is, it has a transmission probe 15 and a reception probe 16 which are ultrasonic probes (flaw detection probes). The transmission probe 15 and the reception probe 16 are disposed to face each other with a product (for example, a steel plate) 17 to be inspected therebetween, and transmit a line focus ultrasonic beam from the transmission probe 15 toward the product 17 almost vertically. Is received by the receiving probe 16 as a flaw detection signal, and the internal defect is detected from the received transmitted wave and reflected wave. To do.

  The signal processing unit 12 includes an existing signal processing board 21, a level-up signal processing board (dedicated board) 22, and a transmission / reception board 23. The existing signal processing board 21 performs signal processing based on the existing signal processing system on the flaw detection signal output from the detection unit 11, and outputs the flaw detection result to the transmission / reception board 23. The level-up signal processing board (dedicated board) 22 performs signal processing based on the new signal processing system that has been upgraded for the flaw detection signal from the existing signal processing board 21, and outputs the flaw detection result to the transmission / reception board 23. The transmission / reception board 23 receives the flaw detection result of the existing signal processing board 21 and the flaw detection result of the dedicated board 22, classifies them, and transmits each flaw detection result.

  Note that the flaw detection signal of the level-up signal processing board (dedicated board) 22 is output from the existing signal processing board 21 because the flaw detection signal is a minute voltage, so that the flaw detection signal is branched before the board and sent to each board. This is to change the flaw and hinder the flaw detection by the existing signal processing system.

  The setting / editing unit 13 receives a flaw detection result of the existing signal processing substrate 21 and the level-up signal processing substrate (dedicated substrate) 22 transmitted from the transmission / reception substrate 23, and a defect editing unit 31 that performs defect editing for each, A preset processing unit 32 that performs preset processing on each of the signal processing board 21 and the dedicated board 22 and transmits the preset processing to the transmission / reception board 23 is provided.

  The display / operation unit 14 includes a transmission editing unit 41 that performs transmission editing for each of the flaw detection results of the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 that have been defect-edited by the defect editing unit 31, and a transmission editing unit. The result screen 42 for displaying the flaw detection results of the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 and preset information of the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 respectively. And a setting screen 43 for setting.

  The preset information set on the setting screen 43 is sent to the preset processing unit 32, where it is processed, sent to the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 via the transmission / reception board 23, respectively. These presets are performed. That is, the setting screen 43 and the preset processing unit 32 function as a setting unit that performs presetting. As will be described later, the setting screen 43 and the preset processing unit 32 have a function of performing a calibration process for matching the outputs of the existing signal processing board 21 and the dedicated board 22 and determining a gain value.

Next, a flaw detection processing operation in the ultrasonic flaw detection apparatus 10 configured as described above will be described.
In actual ultrasonic flaw detection, a line focus ultrasonic beam is transmitted almost vertically from the transmission probe 15 to the continuously transported product 17, and transmitted waves transmitted to the reception probe 16 side and incident from internal defects. The reflected wave reflected is received by the reception probe 16 as a flaw detection signal, and the flaw detection signal is signal-processed by the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 of the signal processing unit 12, and each flaw detection result. Is edited by the defect editing unit 31 of the setting / editing unit 13 and displayed on the result screen 42 of the display / operation unit 14.

  However, since the flaw detection signal is directly input from the receiving probe 16 to the existing signal processing board 21, the flaw detection signal is a raw value, whereas the flaw detection signal input to the level-up signal processing board (dedicated board) 22. Is a signal after the return, so a slight error occurs. Further, if the configuration has a plurality of probes and a plurality of existing signal processing boards, an output error also occurs for each existing signal processing board. For example, as shown in FIG. 2, when the output specification of the signal processing board is 0-1V / 0-30 dB, the existing signal processing board A that has received the flaw detection signal from the flaw detection probe A and the flaw detection signal from the flaw detection probe B Even if the output of 15 dB is output to the level-up signal processing board (dedicated board) in any case from the existing signal processing board B that has received the signal, a difference occurs in the output voltage due to the difference between the existing signal processing boards. For this reason, even if the same defect is detected, there is a high possibility that the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 have different defect signal outputs (echo heights).

  Therefore, prior to the actual flaw detection processing, presetting of the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 is performed by the setting screen 43 of the display / operation unit 14 and the preset processing unit 32 of the setting / editing unit 13. At this time, calibration processing for matching the outputs of the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 is performed, and the gain value of the flaw detection by these two boards is determined.

  As shown in FIG. 3, the calibration process uses a calibration board as a reference, and grasps the echo heights of the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 when the calibration board is flawed. Then, as shown in FIG. 4, in order to adjust these echo heights to the set values, the gain values of the respective signal processing boards are set. 3 and 4, the set value of the echo height (echo value) is 25 dB, the actual echo height at the time of flaw detection on the calibration plate is 24 dB on the existing signal processing board, and the level-up signal processing board (dedicated board). ) Since 22 is 22 dB, the respective gain values are set to +1 dB and +3 dB. By setting the gain value of each signal processing board in this way, the same output (echo height) is output from the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 when the same defect is detected. Can be obtained.

  The specific contents of this calibration process will be described with reference to FIGS. FIG. 5 is a flowchart of the calibration process, and FIG. 6 is a diagram for explaining the operation and gain setting at that time. As shown in these drawings, first, the setting screen is set as a calibration condition screen, and the calibration operation setting is performed on both the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 or the existing signal processing board 21. It is selected whether or not to perform only (ST1). When both are selected, first, calibration processing of the existing signal processing board is executed (ST2). Specifically, the calibration plate is flawed and signal processing is performed on the existing signal processing board 21, and the gain value is calculated from the echo height at that time and the set value of the echo height. During the calibration process of the existing signal processing board 21, the gain value calculation is performed a plurality of times, and the display on the screen is updated every time the gain value is calculated (ST3). After a predetermined time has elapsed, the calibration processing of the existing signal processing board 21 is completed, and the gain value of flaw detection by the existing signal processing board 21 is determined (ST4). Then, the determined gain value of the existing signal processing board 21 is stored, and the result is printed. Next, calibration processing of the level-up signal processing board (dedicated board) 22 is executed (ST5). More specifically, the calibration plate is flawed and signal processing is performed by the level-up signal processing board (dedicated board) 22, and the gain value is calculated from the echo height and the set value of the echo height at that time. During the calibration process of the level-up signal processing board (dedicated board) 22, the gain value is calculated a plurality of times, and the display on the screen is updated every time the gain value is calculated (ST6). After elapse of a predetermined time, the calibration processing of the level-up signal processing board (dedicated board) 22 is completed, and the gain value of flaw detection by the level-up signal processing board 22 is determined (ST7). Then, the gain value of the determined level-up signal processing board (dedicated board) 22 is stored, and the result is printed. This completes the calibration process for the two signal processing boards.

  When actual flaw detection is started, the gain values of the two signal processing boards determined and stored in this way are set by the setting screen 43. The set gain value is processed by the preset processing unit 32 and sent to the existing signal processing board 21 and the level-up signal processing board (dedicated board) 22 via the transmission / reception board 23. Thereby, in an actual flaw detection process, each output (echo height) of the existing signal processing board | substrate 21 and the level-up signal processing board | substrate (dedicated board | substrate) 22 can be match | combined.

  FIG. 7 shows a result of the flaw detection process actually performed using the existing signal processing board and the level-up signal processing board using the gain value determined by the calibration process as described above. 7A is a flaw detection map based on the existing signal processing board, FIG. 7B is a flaw detection map based on the level-up signal processing board, and FIG. 7C is a flaw detection comparison map based on these. As shown in this figure, since the flaw detection result by the existing signal processing board and the flaw detection result by the level-up signal processing board can be displayed simultaneously, these flaw detection results can be easily compared, and the level-up signal It becomes easy to check the performance of the processed substrate. In FIG. 7, the H defect and the M defect represent the size of the defect, and H is larger than M. For example, if the flaw detection threshold is set to 28 dB for H defects and 25 dB for M defects, defects having a flaw detection signal of 28 dB or more are handled as H defects.

As described above, according to the present embodiment, the signal processing unit 12 is provided with the level-up signal processing substrate 22 in addition to the existing signal processing substrate 21, and the flaw detection result detected in the detection unit 11 is used for each signal processing substrate. Signal processing and grasping the flaw detection results separately, the following effects can be obtained.
(1) Online flaw detection using the level-up signal processing board 22 is possible in a state where the signal processing using the existing signal processing board 21 is continued and the quality assurance of the product is maintained. In addition, long-term online data can be collected by level-up signal processing.
(2) Since the detection unit is common, alignment at the time of defect detection is facilitated by flaw detection using the existing signal processing board 21 and flaw detection using the level-up signal processing board 22.
(3) When the existing signal processing board 21 is used and when the level-up signal processing board 22 is used, the output (echo height) when the same defect is detected becomes uniform, and the flaw detection performance can be easily compared. . Also, performance evaluation can be performed in a short time.

  The present invention can be variously modified without being limited to the above embodiment. For example, in the above-described embodiment, the ultrasonic flaw detection apparatus includes the detection unit 11, the signal processing unit 12, the setting / editing unit 13, and the display / operation unit 14, but is not limited to such a configuration. Absent. For example, instead of providing the setting / editing unit 13 and the display / operation unit 14, other combinations may be used.

  Further, the calibration processing for determining the gain values of the existing signal processing board 21 and the level-up signal processing board 22 is not limited to the method of the above embodiment.

DESCRIPTION OF SYMBOLS 11 Detection part 12 Signal processing part 13 Setting / editing part 14 Display / operation part 15 Transmission probe 16 Reception probe 17 Product (steel plate)
21 Existing signal processing board 22 Level-up signal processing board (dedicated board)
23 Transmission / reception board 31 Defect editing section 32 Preset processing section 41 Transmission editing section 42 Result screen 43 Setting screen (setting section)

Claims (5)

An ultrasonic flaw detector that is installed in a continuous line that continuously conveys products and inspects internal defects in the products,
A detection unit having a transmission probe for transmitting an ultrasonic beam to a product and a reception probe for receiving a flaw detection signal based on an internal defect of the product;
A signal processing unit that processes a flaw detection signal from the detection unit;
Based on the flaw detection signal processed by the signal processing unit, a defect editing unit for editing defects,
A display unit for displaying a flaw detection result based on an editing result by the defect editing unit;
A setting unit for presetting the signal processing unit,
The signal processing unit parallels the existing signal processing based on the existing signal processing system and the level-up signal processing based on the new signal processing system with improved flaw detection performance on the flaw detection signal output from the detection unit. Can be operated,
Edit and display each flaw detection signal by these two signal processing by the defect editing unit and the display unit,
The ultrasonic inspection is characterized in that the setting unit sets a gain value of each signal processing determined by performing a calibration process to match the output in the existing signal processing and the output in the level-up signal processing apparatus.   2. The ultrasonic wave according to claim 1, wherein the calibration process performs a flaw detection process for a calibration plate, and determines a gain value so that an output of an existing signal process and an output of a level-up signal process become set values. Flaw detection equipment.   The signal processing unit includes an existing signal processing board that performs existing signal processing and a level-up signal processing board that performs level-up signal processing, and an input of a flaw detection signal to the level-up signal processing board includes the existing signal The ultrasonic flaw detection apparatus according to claim 1, wherein the ultrasonic flaw detection apparatus is performed through a processing substrate. An ultrasonic beam is transmitted from a transmission probe to a product that is continuously conveyed to a continuous line, a flaw detection signal based on an internal defect of the product is received by a reception probe, the received flaw detection signal is signal-processed, and signal processing is performed. An ultrasonic flaw detection method for editing a defect based on a flaw detection signal and displaying a flaw detection result based on the edit
The signal processing is performed by operating in parallel existing signal processing based on an existing signal processing system and level-up signal processing based on a new signal processing system with improved flaw detection performance. Edit and display the flaw detection signal of
Perform calibration processing to match the output in the existing signal processing and the output in the level-up signal processing, determine the gain value of each signal processing, and set the determined gain value to perform ultrasonic flaw detection Ultrasonic flaw detection method characterized by.   The ultrasonic wave according to claim 4, wherein the calibration process performs a flaw detection process on a calibration plate, and determines a gain value so that an output of an existing signal process and an output of a level-up signal process become set values. Flaw detection method.

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