JPS59215216A - Method for marking and reading mark in process control of steel material - Google Patents

Abstract

PURPOSE:To perform automatically marking and reading a mark in a process control of steel material by marking a bar code on the surface of steel material with the aid of a paint spraying device and reading the bar code with the aid of an optical detecting device to treat the read signal. CONSTITUTION:A fillet-shaped mark is marked on a steel pipe B by on-off controlling marking guns 1 while rotating the pipe B. the marking guns 1, the number of which are made equal to the number of digits of control marks, and are turned ON or kept OFF in accordance with a BCD code corresponding to the mark at every time. Next, a paint spraying device A is shifted by a width portion corresponding to one bit with the aid of a motor, and each gun 1 is on-off controlled in accordance with the BCD code, and the code is completed by the sprays of total 4 times. The pipe B is advanced in the direction of an arrow mark 21 and is irradiated by a black light 22, and the excited fluorescence is sensed by an optical detecting device 26 after passing through a slit 23, an UV filter 24, and a TR filter 22. The sensed signal 27 is decoded to an original character-signal by a microprocessor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically marking and reading process control marks on preparations.

For example, in a steel pipe manufacturing line, a technique is required to attach marks, especially control numbers, to steel pipes for process control and to identify these in downstream processes. Conventionally, this has been accomplished by stamping, stenciling, or handwriting characters such as numbers and alphabets that can be easily recognized by the operator upstream of the line, and visually confirming the marks in the downstream process. However, in this method, since a worker is involved in the marking process and the reading process, errors are likely to occur, lacking in reliability, and labor costs are high, resulting in high costs. Furthermore, since this method requires human intervention, there is a problem in terms of processing speed when managing all items whose marks change frequently.

As an alternative method, a method has been proposed in which a sticker with a barcode printed on it is affixed to the steel pipe and automatically read using a code reader in the downstream process. Although this method represents some progress, However, since the sticker peels off due to friction during transportation, there is a limitation that it can only be put to practical use if a place that does not receive friction, such as the inner surface of the pipe, can be used.Also, the process of pasting the pre-printed code sticker is , it is not possible to cope with frequent changes in marking contents.Furthermore, since there is a delay time between printing the 2(- code and pasting the sticker), there is a risk that dragging errors may occur.

The present invention provides a method for marking and reading valuated process control marks without the drawbacks of the conventional methods as described above.

That is, the present invention provides a method for automatically marking and reading process control marks on steel materials, which includes applying a bar code to the surface of the steel material using a paint spraying device, and using an optical detection device to read the bar code. The method includes the following steps: reading a barcode using a Tt71 warning signal and recognizing a control mark by processing a Tt71 attention signal.

The paint spraying device used in the method of the present invention can spray paint in a thin line, and sprays paint at appropriate timing through on/off control in response to a code representing a control mark. The barcode can be any appropriate code such as BCD, E
AN, JAN, C0DE59, NW7, etc. can be used.

The paint can be a paint with a color that contrasts well with the color of the steel, such as white paint. However, the pigment concentration and viscosity are adjusted so that a thin linear spray can be obtained. However, preferably fluorescent paints or inks are used. The 10 points that make the paint fluorescent are explained below.

The barcode is preferably attached to the surface of the steel material in a direction that intersects with the longitudinal direction of the steel material. Particularly in the case of steel pipes and round steel, it is convenient to attach the marks substantially continuously on the circumference, so that readings in downstream processes can be performed from any direction along the circumference of the steel pipe or round steel. Therefore, there is no need to particularly consider positioning during reading. In the method of the present invention, this can be easily carried out using a paint spraying device. Here, the steel pipe is substantially continuous on the circumference of the circular saw, for example, it is wound outwardly on the circumference at right angles to the axial direction, or it has an angle with the axial direction. It includes encircling the circumference for the purpose. However, even if the bar code is made of glands or points that are discontinuous in the circumferential direction, it can be read from one direction without any special positioning when reading, so this applies only. The aspect is also said to be substantially continuous.

To read the barcode, the trap shines light onto the steel material and uses an optical detection device to read the barcode. As the optical detection device, for example, a COD camera, a photodiode, etc. can be used.

When a fluorescent paint is used as the paint, first, fluorescent light (visible light) is emitted by an irradiation source that excites the fluorescent paint, such as an ultraviolet irradiation lamp, and the bar code is read by an optical detection device.

As the optical detection device, a COD camera, a photodiode, or the like is preferably used, which is equipped with a filter that selectively transmits visible light without transmitting ultraviolet light. The method of detecting fluorescent light has the advantage of being able to ignore the influence of ambient light and having a high 8711 ratio of the detection signal. Therefore, there is no risk of misreading due to diffused reflection from the surface of the steel pipe.

As an additional advantage, the marks are not visible to the naked eye under natural and normal light, so there is no need to erase the marks afterwards, streamlining the process.

However, if a paint that is visible to the naked eye is used, there is an advantage that if the reading system fails, a person can easily read it with the naked eye and back it up.

In the present invention, by forming the sensor into a slit shape parallel to the mark, the S/c ratio can be further improved.

The signal read by the optical detection device is digitally processed by a micro processor and then decoded and recognized as a control mark on the original tag.

Exemplary embodiments of the invention will be described with reference to the accompanying drawings.

FIG. 1 shows a paint spraying device (A) and a barcoded steel pipe (B). In the figure, 1 is a marking gun and 2 is a nozzle. A headband-shaped mark (4) is applied by controlling the marking gun (1) on and off while rotating the steel pipe (CB). Marking / is set for each digit number of management marks, and B corresponding to each mark is placed.
It is turned on or remains off according to the CD code, and then the paint sprayer fM is turned on by the width corresponding to one bit.
IB) is moved by a stepping motor, and each gun is controlled on/off according to the BOJJ code.
In the same way, the code is completed by making a total of four sentences. However, if there is no time cycle restriction, the number of guns can be reduced. The number of guns corresponding to the number of digits is not necessarily cheap. For tracking purposes, it is desirable to apply tracking marks (5 and 5') using a tracking mark gun (1'). Further, if necessary, a mark for error detection such as parity check can be added.

FIG. 2 shows an apparatus for reading marks made by the method shown in FIG. When fluorescent paint is used, the steel pipe B is irradiated with an ultraviolet lamp (22) while moving in the direction of the arrow (21). The excited fluorescent light passes through the slit (23),
After passing through the UV filter (24) and the UV filter (25), the liquid is detected by an optical detection device (26).

The sensed signal (27) is decoded by the microprocessor into the original character code.

FIG. 3 shows another embodiment of the invention. Here, steel pipe (B)
The marks are made while the steel pipe (B) is moving in the axial direction without rotating. A paint spraying device is used that applies marks (4) by simultaneously controlling on/off six marking cans (1) installed in the circumferential direction of the steel pipe (B). A code mark is formed by repeating the operation of turning on or keeping off according to the BCD code in accordance with the amount of movement of the steel pipe (B) in the axial direction.

Reading is performed in the same manner as in FIG. 2, as shown in FIG. Here, as an optical detection device, 11 of 1 tube
For example, C with a field of view narrow in one direction and elongated in one circumferential direction.
By using OD cameras, area sensors, etc.
One or two marks (4' and 4') are brought into view. Therefore, one reading device can read from any direction. Although six marking guns (1) were used in the embodiment, the number of marking guns (1) can usually be increased or decreased depending on the width of the field of view of the optical detection device.
If the field of view of the detector is sufficiently wide in the circumferential direction of the oblique tube, detection is possible even with six guns. Unlike Mr. M in FIG. 1, this method is advantageous in that it is not necessary to rotate the f:1 tube during marking and there is no need to stop the movement of the steel tube in the axial direction.

[Brief explanation of the drawing]

Figure 1 shows a paint spraying apparatus and a barcoded steel tube in an embodiment of the method of the invention, and Figure 3 shows a paint spraying apparatus for carrying out another embodiment of the invention. 2 and 4 show an apparatus for reading marks made in the manner shown in FIGS. 1 and 6. FIG. The main symbols in the figure refer to the following. 1 and 1'...Marking gun and tracking mark gun 2 and 2'...Nozzle 4 ・ ・ ・ ノ(-5 and 5'...Tracking mark 22...Ultraviolet light 25...Slit 24 and 25...UV filter and IR filter 2
6...Optical detection device

Claims (1)

[Claims] 1. A method for automatically marking and reading process control marks on steel materials, which includes: applying a pal code to the surface of the steel material using a paint spraying device; and applying an optical barcode to read the bar code. A method for marking and reading process control marks on steel materials, comprising: reading a barcode using a detection device; and processing the read signal to recognize the control mark. 2. The method according to claim 1, in which a fluorescent paint or a fluorescent ink is used as the paint.