JPS59154346A - Defect examining method and device of metallic material - Google Patents

Abstract

PURPOSE:To discriminate efficiently whether trimming of melting-away is required or not by picking up the image of a melting-away flame which melts away the outermost layer part of a metallic material and discriminating and detecting components concerning defective sparks from the photoelectric conversion signal of the picked-up image. CONSTITUTION:The melting-away flame is radiated from a melting-away flame nozzle onto a slab running on a carrying roll, and its defective sparks are picked up by a TV camera 6. Its picked-up image is scanned by vertical and horizontal synchronizing signals from a synchronizing signal generator 11, and the picture signal is given to a level discriminating circuit 12 and a differential binarizing circuit 13. The picture signal and its differential signal are compared with respective thresholds; and when they exceed thresholds, a pulse signal is sent to a counter 15 through an AND circuit 14, and clock pulses from an oscillator 16 are counted. The counted value is sent to a grade discriminating circuit 17, and melting-away start and end signals from a melting-away controller 18 are received; and when a maximum value and an average value of counted values during the time between these signals exceed reference values, an alarm is generated to a control circuit of a melting-away trimming device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inspecting defects in metal materials and an apparatus used for carrying out the method, and specifically relates to a method for inspecting defects in metal materials, and more specifically, defects in the surface layer such as holes, pinholes, sand spots, etc. that exist in the surface layer of metal materials. This paper proposes a defect inspection method for determining whether or not solvent cleaning is necessary by detecting the defects, and an apparatus used to carry out the defect inspection method.

Conventionally, a method for applying solvent directly below the surface of a steel piece, that is, to the surface layer, involves a worker holding a hand scarf torch positioned above the steel piece, scarfing (solvent) the surface of the steel piece,
The area where bright sparks occur when a defect exists is visually observed through dimming glasses, and the solvent is removed more deeply into areas where more sparks are generated. However, if this method is used, the posture of the worker who performs scarfing will be poor, the wave force is the basis, and it cannot be applied to hot steel slabs, and in this case, After cooling the hot-rolled steel billet, it is necessary to carry out the above operations, and then reheat it and hot-roll it. It was necessary to carry out the above-mentioned work on the non-existent steel pieces, and in this case, a large amount of time was wasted, and the problem was that it was not possible to carry out the work efficiently. Since this is done based on the experience and intuition of the operator, there was also a downfall in that there was considerable individual error and it was not possible to carry out even maintenance work.

Raikō 1v"1 was made in view of such circumstances, and a method and method for inspecting defects in metal materials that optically detects defects and further determines whether or not a solvent is required based on the detected value. The purpose of this project is to provide equipment used for its implementation.

The method for inspecting defects in metal materials according to the present invention is based on the method for inspecting defects in metal materials.
The present invention is characterized in that a solvent flame that causes a solvent is imaged, and components related to defective sparks are discriminated and detected from a light weight conversion signal of the captured image.

The invention will be described in detail with reference to drawings showing embodiments thereof. FIG. 1 is a schematic plan view of the mechanical part of the solvent detection device used in carrying out the method of the present invention, and FIG.
It is an enlarged rib view taken along the +i-n line of the figure. The steel billet l is conveyed by a roller conveyor that carries conveyor rolls 2, 2, . . .
It is sent to the installation position of the device of the present invention at right angles to 51+'' .Traveling rail 3
, 3' are arranged parallel to each other in the X-axis direction with the transport roll 2.2 sandwiched between them. Mounting plates 3a, 3a fixed to the electric
It is attached to a base (not shown) via 3a, 3a. Both running rails 3° and 3' have convex cross sections, and a rack 3b is formed at the top of one of the running rails 3 over the entire length in the X-axis direction. On these traveling rails 3.3', the traveling trolley 4 moves in the X-axis direction: 1lI
J is placed at the 11th position. The traveling bogie 4 is a box body that faces in the Y-axis force direction, and an oversized hole is provided in the longitudinal end face facing the traveling rail 3, and the output shaft 7a is inserted into this hole. , a guard morph 7 is attached to its outer surface. A pinion 8 is attached to the tip of the output shaft 7a inserted into the traveling platform if4, and an opening is provided on one side of the traveling vehicle 4 located below the pinion 8. A part of the same song of Vinnie Inn 8 is exposed from this part ('') and meshes with the chic 3b.On the F side of the traveling bogie 4 facing the traveling rail 3', there is a traveling rail. An intermediate tank (not shown) that engages with the wheel 3' and assists in rolling is attached. In the side wall, there is a solvent hole 115 whose tip is tilted downward toward the steel billet l side.
is included in the insertion. From the fixed position 1α of the solvent crater 5 to the upper surface of the traveling carriage 4, which is an appropriate length away from the running rail 3 tr+1, the solvent flame from the solvent hole 5 is directed to the steel piece l J, A television camera 6 is accompanied by a television camera 6 facing the bright region radiated by the beam, and an optical filter 6a for dimming the light is housed in its optical section.

Figure 3 is a block diagram of the signal processing system used for unreleased J.
FIG. 4 is a signal waveform diagram for explaining the first part. The television camera 6 was able to watch the O7. It was installed to image the solvent flame consisting of a mixed gas such as C2H2 and the sparks higher than 1111 degrees (hereinafter referred to as F defect sparks) that occur when there are defects in the surface layer of the steel billet I. can be,
The captured image is scanned by the vertical JIJJ signal and the horizontal synchronizing signal obtained from the 1 signal + generator II, and both image signals are sent to the level discrimination circuit 12 and the differential 2 signal.
It is stored in the value conversion circuit 3.

FIG. 4(a) schematically shows a part of the image signal, and the level discrimination circuit 12 has a
A threshold value (indicated by a dot chain) is set at a level slightly lower than tI&, and the image signal is
A pulse signal as shown in FIG. 4 (b), which is binarized by comparing 1 and 11 and becomes high level when the image signal is higher than the threshold value, is input to one input of the AND circuit 14. Give it to the terminal. The differential binarization circuit 13 first differentiates the image signal from 1 to 1 to obtain a differential signal as shown in FIG. 4 (c).
This is compared with a predetermined value 1 to a threshold (shown by a dashed line), and when the differential No. 44 is at a higher level than the threshold, a pulse signal as shown in FIG. to other input terminals.

The threshold resistance of the differential binarization circuit 13 is set to a value slightly lower than the differential value corresponding to the level change of the image signal due to defective sparks. The AND circuit 14 attains the NO level when both pulse signal inputs are at the high level.
Outputs the /41 pulse signal shown and sends it to Kakunta 15.
as a count enable signal.

The image reliability of the part corresponding to the defective spark in both images suddenly decreased to 1.
Since the voltage level rises and shows a high instantaneous value, the level discriminator circuit generates V and corresponding pulses in both output pulse signals of the differential and binarization circuit 13. On the other hand, the high-intensity part of the flame, A+n<min. in FIG. However, since the changes in both image signals are gradual, the differential binarization circuit 1 of the corresponding part
The output of 3 becomes a low level, and as a result, the AND circuit 14 outputs the number of pulses having a time width corresponding to the magnitude of the defective signal I().

The clock pulse 15 has a sufficiently higher frequency than the time width of the pulse signal output from the AND circuit 14 [Fig.
)] is given as a counting object from the oscillator 16, and the counter 15 counts this tallock pulse as shown in FIG. 4(g) while the output of the AND circuit 14 is at a high level. The vertical direction of the synchronous signal '+ generation 411; (2) signal is used as a timing signal for reading the count value of the class determining circuit 17 and the count value of the counter 15, and is also used as a hetalia signal of the counter 15.

Therefore, the kakunta 15 is one of the images captured by the television camera 6.
The frequency of clock pulses related to the number and size of defective sparks in one frame is counted to quantify the degree of occurrence of defective sparks.
ifi is stored in the '4f class determination circuit I7.

The machining controller 18 is an electric circuit that controls the rotation and stop of the guard motor 7 and the ignition and extinguishing of the solvent hole D5. Guard motor 7 that rotates to the first generation side and moves in the direction of the X-axis force? : While driving, the solvent nozzle 5 is ignited. Then, when a solvent stop command signal is given, the geared motor 7 is stopped, the solvent vent 5 is still extinguished, and the geared motor 7 is reversed to move the traveling carriage 4 backward. When the solvent controller 18 receives the solvent start command signal, the grade determination circuit I7 synchronizes with the solvent start command signal.
A predetermined signal is generated to report the start of the solvent, and when a solvent stop signal is given, a predetermined signal is synchronized to the grade determination circuit 17 to report the end of the solvent. Grade judgment circuit 1
7 calculates the average value and the real dog 11α of the images of a plurality of fields between these two signals as they are read directly from the kakunku 15, and calculates the average value and the real dog 11α for each of the average value and the maximum value, which are preset reference ends. If there are more people than the standard value, a start command signal is issued to the drive control circuit of the full-scale solvent cleaning device a (not shown) installed in the next process, or a predetermined alarm is issued. .

In addition, in the above-mentioned embodiment, the solvent test was carried out using a traveling trolley on the rope piece fixed on the conveyor roll, but the solvent nozzle and the television camera were fixed to a frame installed in the extending direction of the conveyor roll. , Scanning for solvent inspection may be performed by moving the steel piece with a conveyor roll.

In the case of the above-mentioned final completion [y], defects can be inspected automatically regardless of the visual field, which saves manpower, and it can also be applied to hot metal phases (as in the previous example). There is no need to cool down the material to be inspected, so there is no thermal energy loss, and the efficiency of the inspection and maintenance process is significantly improved.Furthermore, the device of the present invention can quantify defects, which is useful for quality control. In the case of the above embodiment, /< /L/discrimination circuit, matching data 2111
Since the image signal is processed by the Ilj conversion circuit, the difference between the solvent hole E' and the steel piece is due to the partial pressure of oxygen in the flame gas that is blown onto the steel piece from [14f or solvent hole 1]. Even if the solvent flame has high brightness locally, it will not be mistakenly detected as a defective spark, and highly accurate defect detection is possible. In addition, if the distance between the solvent hole and the steel piece and the oxygen outside of the solvent flame are maintained stably, the flame brightness will be stable, so the differential binarization circuit can be omitted, resulting in simple signal processing. A device having the same effect as the above-mentioned embodiment can be realized using a circuit.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic plan view of the mechanical part of a solvent testing device used to carry out the method of the present invention, and FIG. 2 is a partially fragmented view. FIG. 3 is a block diagram of the signal processing system used in the invention, and FIGS. 4 (A) to (G) are its operation theory I.
It is a waveform diagram of JIJ Nodame. 1... Steel piece 3, 3' - Running rail 4... Running trolley 6... TV camera 12... Level discrimination circuit
13... Matching binarization circuit 14... 1* logic circuit
15 ・Counter I7... Grade determination circuit patent Presented by Sumitomo Metal Industries Co., Ltd. Agent Patent Attorney Noboru Kono No. 1 Illustration 2 Illustration 3 Illustration 4 Illustration -247-

Claims (1)

[Scope of Claims] 1. In a method for detecting defective sparks generated from defects existing in the surface layer of a metal material when the surface layer of the metal material is treated with a solvent flame, 1. A method for inspecting defects in metal materials, the method comprising: capturing an image of the captured image; and discriminating and detecting a component related to a defective spark from an optical direct conversion signal of the captured image. 2. In a metal material defect inspection device that detects defective sparks generated from defects existing in the surface layer of a metal material when the surface layer of the metal material is treated with a solvent flame, an imaging device that images the solvent flame; a signal discrimination circuit that discriminates components related to defective sparks from the output signal of the imaging device; and an amount of defective sparks generated based on the output signal of the signal discrimination circuit. What is claimed is: 1. A defect inspection device for metal materials, comprising: a circuit for quantifying quantification; and detecting defects based on the quantification results.