JPS622355B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for tracking tubes or bars, and particularly relates to a method for tracking tubes or bars (hereinafter referred to as tubes or bars).
Tracking each bar)
That is, we propose a method that enables piece-by-piece tracking.

Conventional tracking in manufacturing lines for steel pipes, steel bars, etc. uses sensors such as HMDs and CMDs, or passing signals obtained from switches installed on transfer means such as kits, to determine the transfer area and the location of these sensors. The system was designed to control the flow of steel pipes, etc. by detecting entry and exit from appropriately divided areas based on the above. However, with this conventional method, it is only possible to track multiple steel pipes as a group.
In addition, there are interruptions and extractions by transport means such as cranes, which are not subject to tracking, and the piece-by-piece tracking required these days is completely impossible with the conventional method described above. That is, in order to perform piece-by-piece tracking, it is necessary to attach marks for identifying each steel pipe and to identify the steel pipes individually by reading the marks. For this reason, methods using magnetic marks have been tried, but data errors may occur due to magnetic flaw detection or magnetic conveyance means such as magnetic slides.Also, when using paint marks, there may be friction on the roller table, skids, and hourglass shapes. There is a problem in that unspecified parts of the paint barcode attached to the circumferential surface of the end of the pipe or bar material are partially lost due to peeling or staining due to repeated conveyance by rollers.
It has been impossible to construct a highly reliable tracking system.

The present invention has been made in view of the above circumstances, and provides a method for tracking pipes and bars that enables piece-by-piece tracking by improving the method of marking paint marks and the method of reading them. The purpose is to

The method for tracking pipes and bars according to the present invention includes:
Each tube or bar is provided with a bar code in the form of a strip extending substantially around its entire circumference, and at least three bars are provided at different circumferential positions in the transfer area of the tube or bar. The code sensors were installed and the read outputs of these barcode sensors were determined to be correct or incorrect using majority logic.
It is characterized by specifying each pipe and bar using a value signal.

EMBODIMENT OF THE INVENTION The method of this invention will be specifically explained below based on the drawing which shows the Example in a steel pipe manufacturing line. Figure 1 is a schematic diagram of the entire barcode marking device, Figure 2 is a schematic diagram of the entire barcode marking device.
The figure is a schematic elevational view showing the positional relationship between the nozzle and the steel pipe, and FIG. 3 is a schematic diagram of the entire barcode reading device. The marking device is disposed at an appropriate location upstream of the region where piece-by-piece tracking is started in the steel pipe transfer region, and the barcode reading device is disposed downstream from the region. A plurality of barcode reading devices may be provided for each barcode marking device as necessary. In addition, since the method of the present invention uses paint marks, the paint may be burnt out during heat treatment. Therefore, if it is necessary to track the post-process of such heat treatment, a bar should also be placed downstream of the heat treatment. A code marking device must be installed.

Now, the barcode marking device is equipped with turning rollers 11, 11 for stopping the axial direction feeding of the steel pipe P and rotating it around its axis. When the steel pipe P is sent, it moves upward and is removed from the steel pipe conveying means such as the drum-shaped roller (see Fig. 3) 12.
The structure is such that it is lifted up and then rotated in the circumferential direction as shown by the arrow in FIG. Nozzles 13, 13... for spraying paint are located at positions facing the steel pipe P rotated by the turning rollers 11, 11.
They are arranged in a horizontal row at an appropriate distance from the steel pipe P in the longitudinal direction thereof. A mask (stencil) 14 is provided between this nozzle group and the steel pipe P to clearly draw the barcode stripes. This mask 14 is made up of a flat plate with 17 holes of appropriate widths arranged in a horizontal row at equal lengths apart. Therefore, the nozzle 13 and the mask 14
The respective dimensional specifications and the mutual positional relationships among the nozzle 13, mask 14, and steel pipe P are determined so that 17 stripes ST can be drawn on the steel pipe P that can be clearly identified from each other. Feed rate is 1
In the case of ~3 m/sec, the width of the rows is selected to be approximately 5 to 30 mm, and the distance between rows is approximately 10 to 30 mm. Note that the steel pipe size changes depending on the lot, so in order to cope with this, as shown in FIG. The mask 14 is attached to the tip of this mask holder 16.

Each nozzle 13 and a marker liquid supply device 19 disposed at an appropriate location are connected by pipes 18, 18, . . . via electromagnetic valves 17, 17, . The marker liquid force-fed from the marker liquid supply device 19 is ejected from the nozzle 13, and a stripe ST is drawn on the rotating steel pipe P.
The pattern formed by this strip ST is 16-bit data that specifies the steel pipe, and the strip ST drawn by the most advanced nozzle is a position mark to instruct the barcode reading device described later to start reading. The content of the subsequent ST, ie code mark, differs depending on the steel pipe, whereas the position mark is always drawn.

20 is a marker liquid supply device 19 and a solenoid valve 17;
17..., etc., and detects that the steel pipe P has arrived at the position where the barcode marking device is disposed by the operation of a micro switch (not shown) or other components, and rotates the turning rollers 11, 11. At this time, the supply device 19 is activated to forcefully feed the marker liquid, and the marker liquid is ejected from the position mark nozzle 13, and the code mark nozzles 13, 13, . . .
Open the required solenoid valve 17 to eject marker liquid from a predetermined one of..., and open the other solenoid valve 1.
7 remains occluded.

The digital switch 21 is used to set the numerical value of the barcode, and its output is input to the controller 20, which converts the multi-digit numerical value set in the digital switch 21 into a 16-digit binary code. The opening and closing of the electromagnetic valve 17 is controlled so as to draw a line on the steel pipe. Note that the numerical value set by the digital switch 21 is for the first steel pipe, and subsequent bar codes are automatically incremented as the counter inside the controller 20 advances. Of course, a configuration in which the codes for each tube are set one by one manually or by a host computer is also possible. Digital switch 22
is for setting the marking time, and its output is also input to the controller 20, and the controller 20 controls the solenoid valve 1 for a time corresponding to the set value.
Open 7. Since the rotational speed of the turning rollers 11, 11 is constant, it is set to a longer time for a large diameter pipe, and to a shorter time for a small diameter pipe. Note that as the marker liquid, it is sufficient to use any marker liquid that has been conventionally used for this type of use.

Next, the barcode reading device will be explained. As shown in FIG. 3, three barcode sensors 31,
2 and 33 are positioned at three equal intervals in the circumferential direction of the steel pipe P, specifically, at the bottom and diagonally above the left and right. It goes without saying that the lower sensor 31 is positioned in the gap between the plurality of drum-shaped rollers 12 so as to face the steel pipe P.

Appropriate photoelectric sensors may be used as the sensors 31, 32, and 33, and the width dimension or inter-strip dimension of the above-mentioned strips ST, as well as the separation dimension between the steel pipe and the sensor, may be appropriately determined depending on the characteristics of the sensor used. Just set it. Generally, the distance between the steel pipe surface and the sensor is
A value of about 50 to 100 mm is good. If this dimension is too short, especially less than 50 mm, the detection output of the shiny part due to peeling off of the black skin will be approximately the same as the output when detecting a white stripe, for example. Data may be misread. Each sensor 31, 32, 33 has a column 41,
The holders 51, 52, 53 are attached to the holders 51, 52, 53, which are attached to the holders 42, 43 so as to be able to freely set the vertical positions, and the holders 51, 52, 53 are attached to the holders 51, 52, 53 so as to be able to move toward and away from the center of the steel pipe conveyance area and to fix the position.
Each sensor is positioned according to the outer diameter of the tube so as to have an appropriate size within the above-mentioned range and to be approximately equally spaced from the surface of the steel tube. Note that it is convenient for the sensors 31, 32, and 33 to have their optical axes not perpendicular to the axis of the tube, but to be inclined within a range of 10 to 30 degrees, since this will result in a higher S/N ratio. This is because, depending on the surface properties of the steel pipe, if the detection surface of the sensor is placed perpendicularly to the pipe surface, surface reflections between the strips may cause the detection surface to be mistaken for strips ST. In addition, as a method to improve the reading accuracy of the sensors 31, 32, and 33, lines are drawn with fluorescent paint.
It is also possible to darken the arrangement area and read the stripes using a black light.

The outputs of sensors 31, 32, and 33 are three AND
Gates 34, 35, 36 and one OR gate 3
The signal is input to a majority logic circuit 38 consisting of 7. That is, the output of sensor 31 (32 or 33) is AND
One input each of gates 34 and 35 (35 and 36, or 36 and 34), which allows OR
The output of the gate 37 is "1" when the output of any two or more of the sensors 31, 32, 33 is "1" (when a strip is detected), and the output of any two or more is "0". (if no article is detected)
becomes “0”. The output of this OR gate 37 is input to a series/parallel conversion circuit 39 using a shift register or the like.

44 is a pulse generator connected in conjunction with the drum-shaped roller 12, which generates a number of pulses according to the amount of movement of the steel pipe (or pulses with a period according to the speed of movement)
Output. The amount of movement of the steel pipe per pulse is preferably set to the pitch of the barcode (pitch of the strip ST)/n (n is a natural number).
The output of 4 is input to the n frequency divider circuit 45. The n frequency divider circuit 45 starts operating with the signal when the OR gate 37 reads the position mark of the row ST, and outputs one pulse for every n input pulses from the pulse generator 44. Pulse is series/
The signal is applied as a shift pulse to a serial input/parallel output type shift register constituting the parallel conversion circuit 39. With this configuration, a 16-bit barcode is read into the conversion circuit 39 as a combination of binary data of "1" or "0", and is then read into the code conversion circuit 46 as 16-bit parallel data at a separately given timing. It is set to be loaded. This code conversion circuit 46 converts input data into a format that matches the data system of a host computer such as a process control computer, and outputs the converted data.

In addition, in the above embodiment, facing the conveyance area of steel pipes,
Although the case has been described in which one reading output having three barcode sensors is provided for each reading location, the invention is not limited to this type. For example, a steel pipe is kept stationary in a conveying area, and the reading The barcode may be read by moving the device at a constant speed in the longitudinal direction of the steel pipe, and 17 sensors (the number of sensors is 17 x 3 or more) per reading location may be moved along the length of the steel pipe at the spacing of the barcodes. The 16-bit code may be read simultaneously at the timing when the reading start mark is detected.

The method of the present invention carried out as described above draws a barcode strip around the entire circumference of a tube or bar, and reads it using a plurality of sensors installed at different positions in the circumferential direction. Since the read output is judged to be correct or incorrect based on majority logic, friction on the table and repeated conveyance by skids and drum-shaped rollers can cause unspecified parts to peel off and stains, resulting in paint barcodes being damaged. Even if the barcode partially disappears, the possibility of misreading the barcode can be made extremely low. Therefore, according to the method of the present invention, even in an environment where pipes and bars are repeatedly conveyed by skids, drum-shaped rollers, etc., tracking can be realized in which the pipes and bars are managed piece by piece with high precision.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall schematic diagram of a barcode marking device used to carry out the method of the present invention, and FIG. 2 is a schematic diagram showing the positional relationship between a nozzle and a steel pipe. The elevational view, FIG. 3, is an overall schematic diagram of the barcode reading device. 11... Turning roller, 13... Nozzle,
14... Mask, 17... Solenoid valve, 20... Controller, 31, 32, 33... Barcode sensor, 38... Majority logic circuit.

Claims (1)

[Claims] 1. In a tracking method that tracks the flow of transferred pipes and bars together with information, each pipe and bar is attached with a bar code that depicts a strip that extends substantially all the way around the pipe and bars. At least three barcode sensors that read different positions in the circumferential direction of the tube/bar are arranged in the transfer area, and the reading outputs of these barcode sensors are determined to be correct or incorrect using majority logic. A method for tracking pipes and bars, characterized by identifying each pipe and bar using a value signal.