JPH05318132A - Welding equipment for strip continuous processing line and its welding determining method - Google Patents

Abstract

PURPOSE:To surely determine the quality of a welding state in the welding equipment for the strip continuous processing line. CONSTITUTION:A tail end of preceding material and the tip of succeeding material are superposed on each other and a connecting part is subjected to seam welding by electrode rings 3. The thickness of the connected part after welding is then measured at a welding starting point and completion point by a finished thickness measuring instrument 4. Accordingly, the quality of the welding state can be determined by comparing the finished thickness of the welded zone measured by the finished thickness measuring instrument 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding apparatus for continuous strip processing, which can diagnose the quality of the welding state during the welding operation between strips in a continuous strip processing line.

[0002]

2. Description of the Related Art Conventionally, in welding work between strips used in a continuous strip processing line, the end faces of the strips are cut, overlapped by a predetermined amount, and the overlapped portions are sandwiched vertically by a roll electrode. -Generally, it is carried out with a welding device that melts the ends while energizing.
Welding work with such welding equipment requires appropriate conditions such as welding current and electrode wheel pressure.To determine these, the welding current, electrode wheel pressure, and overlap margin are changed in advance based on the sample of the cutting plate. The welding test is performed, and the sample is subjected to a tensile test or a destructive test such as an extension test called an Erichsen test to determine the superiority or inferiority of the welding state, and the welding conditions are determined based on the determination.

However, in the judgment method by such a fracture test, during actual operation, for example, after welding different width materials, the strip-side end portion which obstructs the passage of the strip is cut out in an arc shape, and the cutout piece is broken. The method is limited only to a test or a method of directly hitting the welded portion and confirming it, and it has not necessarily been made to judge a welding defect (in the width direction of the strip) of the welded portion.

In order to solve such a problem, for example, as shown in Japanese Patent Laid-Open No. 63-203285, the strip lap thickness at the time of welding and the temperature of the welded portion immediately after welding are detected, and the current is passed. A method has been devised to determine the welding state by multiple regression analysis based on measured values such as current and clamp pressure.However, the sensors at the detection end may be affected by noise, so the correlation between data Is difficult to grip, and thus it is difficult to detect the welding failure properly. Further, in the method of determining using the melting temperature during welding, a phenomenon occurs in which the temperature transiently rises when the roll electrode rides on the strip at the welding start portion, so in the determination method that uses only welding temperature, Similar to the above, welding defects cannot always be detected accurately. As described above, in each welding diagnostic apparatus, it was difficult to grasp the correlation between the measurement result from the detection end and the welding state, which was an obstacle to practical use.

[0005]

In view of the problems of the prior art as described above, the main object of the present invention is to judge the quality of the welding state based on the variation of each condition during welding as in the prior art. Rather, it is to provide a welding device for a continuous strip processing line that determines the quality of the welded state by measuring the finished thickness after welding.

[0006]

According to the present invention, the above-mentioned object is achieved by superposing the tail end of the preceding material and the tip of the following material so that the tail end of the preceding material and the tip of the following material are A welding device for a strip continuous processing line, in which the electrode wheel is welded by rolling the electrode wheel from one end to the other end of the overlapping margin, and a strip at a welding start point and an end point at least. The present invention is achieved by providing a welding device for a continuous strip processing line, which is equipped with a finished plate thickness measuring device that measures the welding thickness. Furthermore, the tail end of the preceding material and the tip of the trailing material are overlapped, the tail end of the preceding material and the tip of the following material are clamped, and the electrode wheel is moved from one end of the overlapping margin to the other end. Weld the part by rolling it toward each other, measure the strip welding thickness at least at the starting point and the ending point of the welding, and compare the measured values of the starting point and the ending point of the welding. It is also achieved by using a welding determination method for a strip continuous processing line welding apparatus, which is characterized in that

[0007]

By doing so, the tail end of the leading material and the tip of the trailing material can be welded by the electrode wheel, so that the leading material and the trailing material can be continuously threaded. And
With the finished plate thickness measuring instrument, the plate thickness of the connection portion after welding can be measured at least at the welding start point and the end point, and therefore, based on each of these measured values, for example,
It can be useful for determining the quality of welding depending on whether or not the difference when comparing these measured values exceeds a predetermined value.

Further, in the present invention, as described above, the quality of welding of the strip connection portion is judged by the difference in the finished thickness at the starting point and the ending point of the welding. , If the overlap margin of the connection between the preceding material and the following material is kept constant at the welding start point and the end point, the welded state will be uniform in the plate width direction, and the finished thickness of the welded part after welding will also be Although it remains constant, it was found that the overlap margin is reduced by elastic deformation of the clamp and the body frame by the reaction force due to the pressure applied by the roll electrode during welding.

As a result of further studies from the above, as shown in FIGS. 3 and 4, in seam welding, it is clear that the range G surrounded by the straight line X and the straight line Y is good. Became. Then, it is judged whether or not the difference in the finished plate thickness between the start point and the end point of welding is in the range G, and if it is out of the range, an alarm is given and re-welding or low tension threading is taken. By doing so, it is possible to prevent breakage of the threaded plate in advance.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. 1 and 2 are diagrams showing a main part of a welding device for a continuous strip processing line to which the present invention is applied. For example, two units (not shown) are provided at the inlet side of a continuous annealing line. It is used for seam welding the tail end of the preceding material and the leading end of the following material so that strips sequentially unwound from the pay-off reel are passed through the annealing furnace without breaks.

The strips 1a and 1b pulled out from the two payoff reels are respectively pressed and held by the clamper 2, and the tail end of the preceding strip 1a and the leading end of the following strip 1b overlap each other. Is held in. The roll electrode 3 provided between the clampers 2 welds the connecting portions of the strips described above by seam welding while rolling from one end to the other end in the plate width direction.

Further, the roll electrode 3 is on the opposite side of the traveling direction (see FIG. 1).
A roller 4 for welding finishing is provided on the right side of FIG. 1) so as to crush the convex portion formed on the surface of the connecting portion immediately after welding. On the opposite side of the welding finishing roller 4 in the traveling direction (on the right side in FIG. 1), there is provided a finished plate thickness measuring instrument 5 for measuring the plate thickness of the connection portion after welding.
The finish plate thickness measuring device 5 may be either a contact type or a non-contact type, but in the present embodiment, optical plate thickness gauges that are not easily affected by temperature are arranged above and below the overlapping portion. And the plate thickness after welding was measured.

A gap sensor 6 is provided on each clamper 2, and the gap between the pair of upper and lower clampers 2 is measured to determine each strip 1a, 1b.
It is designed to measure individual plate thickness. The plate thickness measuring device 5 and the gap sensor 6 are electrically connected to the controller 7, and all the measured plate thickness information is input to the controller 7. Further, a buzzer 8 is electrically connected to the controller 7 so that the buzzer 8 can be activated when welding is defective.

Next, the operation procedure of the device of the present invention will be described. The tail end of the preceding material 1a is aligned with the position of the roll electrode 3 and the position is fixed by the clamper 2. At the same time, the gap sensor 6 measures the plate thickness of the preceding material 1a. On the other hand, the tip of the trailing material 1b is overlapped with the tail end of the leading material 1a, the position is fixed by the clamper 2, and the plate thickness is measured by the gap sensor 6. The plate thickness measurement values of the strips 1a and 1b thus obtained are transmitted to the controller 7 and internally processed to set proper welding conditions. Based on this, the welding current applied to the roll electrode 3 and the electrode pressing force are set, and mash seam welding is performed.

Then, the welding finishing roller 4 crushes the surface convex portion of the connection portion immediately after welding. After this, the finished plate thickness measuring device 5 measures the plate thickness of the welded portion from the welding start point to the welding end point. Then, the measured value of the plate thickness of this connection portion is transmitted to the controller 7 as occasion demands and internally processed. At this time, as shown in FIG. 4, by comparing the sum of the plate thicknesses of the preceding material 1a and the following material 1b, which were previously measured in the pretreatment, with the plate thickness value of the connection portion, good welding conditions were obtained. It is determined whether or not it is within the range, that is, the difference ΔT in the finished plate thickness between the welding start point and the welding end point of the connection portion after being connected by seam welding.
Is within the range of the good welding strength region G given by the two straight lines X and Y shown by the broken line in FIG.
When the difference ΔT in the finished plate thickness is out of the good welding strength range G, the buzzer 8 issues an alarm and measures such as re-welding are taken.

The mounting position of the finished plate thickness measuring instrument 6 is
After welding, the welded part is completely solidified, and the welded part can be mounted at any position where the maximum width of the welded part can be measured. It is also possible to detect the stroke variation of the finishing roller 5 and measure the plate thickness of the connection portion after welding.

[0017]

As is apparent from the above description, according to the welding apparatus for continuous strip processing line of the present invention, the quality of the welded portion is monitored by monitoring the difference in the weld finish thickness at the welding start point and the welding end point. Can manage
Since it is possible to detect the breakage of the welded portion in advance, it is possible to dramatically improve the operating rate of the line. Further, by using the method for determining the quality of welding according to the present invention, it is possible to obtain the same effects as those described above.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the device of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 3 is a diagram showing a welded plate thickness from a welding start point to a welding end point.

FIG. 4 is a diagram for explaining a method of determining welding quality.

[Explanation of symbols]

 1 Strip 2 Clamper 3 Roll Electrode 4 Welding Finishing Roller 5 Finished Plate Thickness Measuring Device 6 Gap Sensor 7 Controller 8 Buzzer

Claims (2)

[Claims] 1. The tail end of the preceding material and the tip of the trailing material are overlapped with each other, and the tail end of the preceding material and the tip of the following material are clamped, and the electrode wheel is attached from one end of the overlapping margin. A welding device for a continuous strip processing line that welds a connecting portion by rolling toward the other end, comprising a finish plate thickness measuring device that measures at least the strip welding thickness at the welding start point and the welding end point. Characteristic welding equipment for strip continuous processing line. 2. The tail end of the preceding material and the tip of the trailing material are overlapped with each other, and the tail end of the preceding material and the tip of the following material are clamped, and the electrode wheel is attached from one end of the overlapping margin. By welding the connection portion by rolling toward the other end, at least measuring the strip welding thickness at the welding start point and the end point, by comparing each measured value of the welding start point and the end point, A welding determination method for a strip continuous processing line welding apparatus, characterized by determining the quality of welding.