JPH067845A - Detection method for welded and joined part of continuous hot rolling - Google Patents

Abstract

PURPOSE:To improve yield of cutoff by detecting the welded and joined part with high accuracy. CONSTITUTION:In a continuous hot rolling line 9, a cold piece is pressed in contact on a weld zone by a joined part cold piece press-contacting machine 3 in receipt of a tracking signal 2a from a sheet bar joining machine, a CCD camera 6 of a luminosity detecting system is provided right before an inlet side cutting machine 5 of a winding device 4 to detect the difference of the temperature of a steel sheet, simultaneously, the shape of the cold piece is recognized, the welded and joined part is detected and cutting is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting welded joints in continuous hot rolling.

[0002]

2. Description of the Related Art Welding joint detection technology currently proposed as a method for detecting welded joints in continuous hot rolling is the joining of the trailing edge of the preceding material and the leading edge of the following material in the final stand of the finishing rolling mill. Depending on the difference in rolling load between the parts, the technology to detect the joint, the thickness of the joint, the width of the joint, the difference in emissivity is detected by the thickness gauge, width gauge, thermometer installed immediately before the cutting machine, There is a technique in which the certainty of the joint is obtained from such information to make the tracking function more reliable (see Japanese Patent Laid-Open No. 4-89136).

[0003]

In the technique for detecting the joint portion by the change of the rolling load, the joint portion may be erroneously recognized due to the error of the load fluctuation portion, or the joint may not be detected when the load cell is abnormal. Also, the method of detecting changes in plate thickness, plate width, and emissivity seems to be an appropriate tool to be used as an auxiliary position of the tracking function, but we guess the difference between the state of the joint and other parts. However, in the case of successively rolling sheets of the same size, it is necessary to take a method that does not fit the original rolling, such as shifting in the width direction and joining.

In the present invention, in consideration of these problems,
It is an object of the present invention to provide a more reliable technique for detecting a joint by processing the joint and detecting it.

[0005]

In order to solve the above-mentioned problems, the present invention crimps a thin cold piece to the joint after welding, differentiates the temperature of the surface of the steel sheet around that portion, and the surface of the steel sheet due to the temperature difference. The CCD camera detects the difference in the light emission state of the. In this case, the temperature difference can be detected and at the same time, the temperature distribution thereof can be image-processed to assist in distinguishing between the welded joint and the other low temperature portion such as a scale.

[0006]

According to the present invention, the position of the welded joint of the steel sheet can be accurately detected by introducing the cold piece crimping device for detecting the joint and the CCD camera for detecting the low temperature region of the joint. Therefore, while eliminating the malfunction of the disconnection process,
It is possible to avoid a decrease in yield due to erroneous cutting or the like.

[0007]

1 is an explanatory view of a pass line 9 for continuous hot rolling to which the present invention is applied. The hot-rolled sheet bar rough-rolled by the rough rolling mill 7 is welded to the tail end of the preceding sheet bar by the sheet bar joining machine 2 on the upstream side of the hot finish rolling mill 1, and the leading end of the succeeding sheet bar is continuously welded. It is supplied to the finish rolling mill 1.

[0008] The finish-rolled strip is cut at the welded portion by a cutting machine 5, and the down coiler 4 is cut for each strip.
To be wound up. In the present invention, the joining portion cold piece crimping machine 3 is provided immediately after the sheet bar joining machine 2, and the joining portion cold piece detecting CCD camera 6 is provided immediately before the cutting machine 5 to detect the welding joining portion. The joint cold piece crimping device 3 has a function of placing a cold piece on the joint portion and a function of embedding it in a steel plate with a crimping roll. The position of the joining portion is detected by receiving the tracking signal from the sheet bar joining machine 2. A simple structure of the joint cold piece crimping machine is shown in FIG.

The cold piece crimping device 3 has a tracking processing device 8 for receiving the tracking signal 2a from the sheet bar joining machine 2, and the tracking processing device 8 drives the crimping device 10 to attach the cold piece to the joint portion. The pressure-bonding roller 11 embeds this in the sheet bar and pressure-bonds it. FIG. 3 shows the arrangement of the cutting CCD camera and the interface with the cutting machine. CC
The D camera 12 detects a cold piece. After the camera detects the joint, the information is analyzed, and the CCD camera controller 14 sends the tracking information 15 to the cutting machine 13.

[0010]

In the welding of the present invention, a cold piece serving as a mark is attached to the joint and detected, so that the welded joint can be detected with high accuracy, and as a result, the yield of cut-off is improved. .

[Brief description of drawings]

FIG. 1 is a layout view of a hot rolling line and each device.

FIG. 2 is a simplified structural diagram of a cold piece crimping machine for a joint portion.

FIG. 3 is a diagram showing an interface between a CCD camera and a cutting machine.

[Explanation of symbols]

 1 Finishing Rolling Machine 2 Sheet Bar Joining Machine 2a Tracking Signal 3 Cold Bonding Machine for Bonding Section 4 Down coiler 5 Cutting Machine 6 CCD Camera for Detecting Bonding Cold Section 7 Rough Rolling Machine 8 Tracking Processing Device 9 Pass Line 10 Crimping Device 11 Crimping Roller 12 CCD camera 13 Cutting machine 14 CCD camera control unit 15 Tracking information

Claims (1)

[Claims] 1. In a continuous hot rolling line, a cold piece is pressure-bonded to a welded portion of a steel plate, and immediately before the steel plate is cut on the side where the winding device enters, a difference in temperature between the steel plates is detected by a CCD camera of a self-luminous detection system. In addition, the method for detecting a welded joint in continuous hot rolling is characterized by recognizing the shape of the cold piece and detecting a welding point.