JPH10197466A - Seam weld condition judging apparatus having function of checking for visual field position of radiation thermometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately judge the propriety of weld condition while adjusting a visual field position of a radiation thermometer with easier checking by checking for the position depending on the projected position of a light spot radiated through a condenser lens from a projector. SOLUTION: A weld condition judging device 11 compares the temperature of a seam weld part measured by a temperature measuring device 7 with the optimum temperature thereof to judge the propriety of the weld condition of the seam weld part from the results of the comparison. A visual field position checker checks for the visual field position in the measurement of temperature with a radiation thermometer 7 depending on the projected position of a light spot radiated through a condenser lens 8 from a projector 14. A light combining device 16, the condenser lens 8, the body 10 of the thermometer and the projector 14 are interconnected by an optical fiber 9. This enables accurate judgment of the propriety of the weld condition of the seam weld part while adjustment of the visual field position in the measurement of temperature of the radiation thermometer for measuring the temperature of the seam weld part with easier checking therefor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seam welding state determination device having a function of confirming a visual field position of a radiation thermometer, and more particularly to a method for accurately determining the quality of a welding state of a seam welding portion and controlling the temperature of the seam welding portion. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seam welding state determination device having a radiation thermometer visual field position confirmation function that can easily confirm and adjust the temperature measurement visual field position of a radiation thermometer for measurement.

[0002]

2. Description of the Related Art For example, in a continuous plating line for a thin steel plate (hereinafter referred to as a strip), a preceding strip and a following strip are joined to each other by a seam welding machine. This seam welding is performed as follows.

[0003] The operation of the continuous line is suspended, and the tail end of the preceding strip and the leading end of the following strip are overlapped in a seam welding machine. Next, the preceding strip and the following strip are fixed by a clamp device, and the overlapped portion is cut by a shear. Next, the preceding strip and the following strip are again overlapped with a width of about 2 to 3 mm. Next, welding conditions such as welding current, welding speed, and electrode pressing pressure are set based on the thickness, material, and the like of the preceding strip and the following strip, and under these welding conditions, a disc-shaped conductor, that is, an electrode The wheel is pressed against the upper and lower surfaces of the strip, and this is run while energizing over the entire width of the strip. Thereby, the overlapped portion is heated and pressed by electric resistance to be joined.

[0004] In this way, the leading strip and the trailing strip are joined, but if the welding state of the seam weld is poor, a serious accident such as a line stop due to breakage of the weld in the subsequent process is caused. Therefore, it is extremely important to determine the quality of the welding state of the seam weld.

Conventionally, the quality of the welding condition of a seam welded portion is determined online by visually observing the welding fire color and spatter scattering at the time of welding, and based on the feeling and experience of the operator, or by performing the seam welded portion. It has been carried out by a method such as a hammer test method in which the strength of the seam weld is confirmed by hitting with a hammer. However, with these methods, it is difficult to quantitatively evaluate the quality of the seam welded portion, and it has been difficult to completely avoid line trouble due to poor welding.

A method for solving this problem is disclosed in, for example,
-203285. This method
In the seam welded portion, the relationship between the thickness of the overlapping portion of the strip and the temperature range in which welding is favorably performed is stored in a controller in advance, and the thickness of the overlapping portion of the strip at the time of welding and the welded portion immediately after welding are stored. Is introduced into the controller to determine the quality of the welding condition.

[0007]

The welding condition of the overlapping portion of the strip depends on various factors. For example, changes in welding current, welding speed, that is, running speed of the electrode wheel, pressing pressure of the electrode wheel, stripping allowance, etc., all appear as changes in the temperature of the weld.

Therefore, the measurement of the temperature of the welded portion is extremely effective in determining the quality of the welding condition. When it is determined that the welding state is bad, welding is performed again. However, when the line is operated at a high speed, there is often no time margin for performing welding twice. again,
If the strip breaks in the line by operating the line with poor welding without welding, the damage caused by this is severe. Therefore, in order to prevent the strip from breaking, it is more economical to perform re-welding even if the line is stopped. For this reason, the welding state determination device is required to have a highly accurate quality determination result.

However, the temperature measurement value due to the welding temperature changes not only due to the mechanical change in the welding machine and the welding state, but also due to the displacement of the temperature measurement visual field position of the thermometer. When such a state occurs, the conventional welding state determination device cannot easily determine whether the temperature measurement visual field position of the thermometer has shifted or whether the welding temperature has really changed. .

[0010] The deviation of the temperature measurement visual field position of the thermometer becomes a serious problem for the following reason. As described above, the overlapping allowance of the strip is 2 to
Since the width of the electrode ring is about 10 to 20 mm, the heating width of the welded portion is at most 5 to 10 mm.
It is about. On the other hand, it is necessary to use a non-contact type thermometer such as a radiation thermometer as a means for measuring the temperature of the welded portion. It becomes an average temperature including the temperature of the part, and accurate measurement cannot be performed. Therefore, the diameter of the field of view needs to be as small as possible. Since the thermometer needs to measure the temperature immediately after welding, it is desirable that the thermometer be as close as possible to the electrode wheel. However, the electrode wheel is repeatedly heated and cooled each time welding is performed while being strongly pressed against the strip, and the surface is roughened due to scattering of spatter. In such a state, normal welding cannot be performed, so the electrode wheel surface must be ground periodically. For this reason, since the diameter of the electrode wheel gradually decreases, the electrode wheel must be replaced at a predetermined cycle. In addition, touching the thermometer when performing these operations also shifts the mounting position of the thermometer. In this case, as the visual field diameter is smaller, the influence of this shift becomes greater, and the temperature of the welded portion may not be measured normally.

As the thermometer used here, an optical fiber type radiation thermometer is preferable in terms of installation space. Conventionally, however, in order to adjust the position of the temperature measurement visual field in this radiation thermometer, a connection to the radiation thermometer is required. The connector of the optical fiber was detached, light was emitted from this through a flashlight or the like, and the position of the radiation thermometer was adjusted so that the light emitted from the condenser lens came to the reference position.

However, this method has a problem that it takes a long time, and it is difficult to perform adjustment because the amount of light of the flashlight is insufficient. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to accurately determine the quality of the welding state of the seam weld, and to measure the temperature of the radiation thermometer for measuring the temperature of the seam weld. It is an object of the present invention to provide a seam welding state determination device having a visual field position confirmation function of a radiation thermometer, which can easily confirm and adjust a measurement visual field position.

[0013]

According to the first aspect of the present invention,
Radiation thermometer for measuring the temperature of the seam weld in order to judge the quality of the welding state of the seam weld of the preceding strip and the succeeding strip in the continuous metal strip processing line joined by the seam welder In the seam welding state determination device provided with, the seam in the case where the welding state of the seam welding part is good, which is preset according to the temperature of the seam welding part measured by the radiation thermometer and welding conditions. Comparing the optimum temperature of the welded portion, based on the comparison result, a welding state determiner for determining the quality of the welding state of the seam welded portion,
A light projector for emitting light from the condenser lens of the radiation thermometer when the seam welding machine is retracted outside the continuous metal strip processing line; and light emitted from the light projector through the condenser lens. It is characterized in that it comprises a visual field position confirmation jig for confirming the visual field position of the radiation thermometer according to the projection position of the spot.

According to a second aspect of the present invention, the seam welding is performed to determine whether or not a welding state of a seam welded portion between a preceding strip and a following strip in a continuous metal strip processing line joined by a seam welding machine is good. In a seam welding state determination device provided with a radiation thermometer for measuring a temperature of a portion, the seam welding temperature measured by the radiation thermometer and the seam welding preset according to welding conditions, A welding state determiner for comparing the optimum temperature of the seam welded part when the welding state of the seam welded part is good, and determining whether the welding state of the seam welded part is good or not based on the comparison result; A floodlight for emitting light from the condenser lens of the radiation thermometer when the welding machine is retracted outside the continuous metal strip processing line; The screen comprises a screen on which light emitted from the projector through the condenser lens is projected, and an imaging unit for imaging a light spot projected on the screen in order to confirm a visual field position of the radiation thermometer. In particular, it has features.

According to a third aspect of the present invention, the seam welding is performed to determine whether or not the welding state of a seam welded portion between a preceding strip and a following strip in a continuous metal strip processing line joined by a seam welding machine is good. In a seam welding state determination device provided with a radiation thermometer for measuring a temperature of a portion, the seam welding temperature measured by the radiation thermometer and the seam welding preset according to welding conditions, A welding state determiner for comparing the optimum temperature of the seam welded part when the welding state of the seam welded part is good, and determining whether the welding state of the seam welded part is good or not based on the comparison result; A floodlight for emitting light from the condenser lens of the radiation thermometer when the welding machine is retracted outside the continuous metal strip processing line; A screen on which light emitted from the light projector through the condenser lens is projected, and an imaging unit for imaging a light spot projected on the screen to confirm a visual field position of the radiation thermometer; and It is characterized in that it comprises a visual field position automatic adjusting means for automatically adjusting the visual field position of the radiation thermometer based on the visual field position data by the imaging means.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the seam welding state judging device of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a seam welding state judging device according to claim 1, FIG. 2 is a block diagram showing a main part of the seam welding state judging device according to claim 1, and FIG.
FIG. 4 is a schematic perspective view showing an installation state of a visual field position checking jig.
Fig. 5 is a view taken in the direction of the arrow A in Fig. 3, Fig. 5 is a block diagram showing a main part of the seam welding state judging device according to the second embodiment, and Fig. 6 is a main part of the seam welding state judging device according to the third embodiment. FIG.

1 to 4, reference numeral 1 denotes a trailing strip, 2 denotes a preceding strip which is seam-welded to the trailing strip 1, and 3 denotes a carriage movable by wheels 4. The carriage 3 is provided with an upper electrode wheel 5A, a lower electrode wheel 5B, an upper swaging roll 6A, and a lower swaging roll 6B. Reference numeral 7 denotes a radiation thermometer, which includes a lower electrode wheel 5B and a swaging roll 6B.
And a converging lens 8 and a thermometer main body 10 installed between them.

Reference numeral 11 denotes a welding state determiner in which the optimum temperature of the seam welding portion when the welding state of the seam welding portion between the succeeding strip 1 and the preceding strip 2 is good is preset. The optimum temperature is determined in advance based on the thickness and steel type of the succeeding strip 1 and the preceding strip 2 previously input from the host computer 12 and welding conditions sent from the seam welding machine controller 13 described later. You. The welding state determiner 11 compares the temperature of the seam welded portion measured by the temperature measuring device 7 with the optimum temperature of the seam welded portion, and determines whether the welding state of the seam welded portion is good based on the comparison result. judge.

Reference numeral 14 denotes a projector for generating light such as a laser beam. The projector 14 emits light from the condenser lens 8 of the radiation thermometer 7 when the seam welding machine is retracted outside the continuous metal strip processing line. It is radiated toward the visual field position confirmation jig 15.

Reference numeral 15 denotes a visual field position confirmation jig for confirming the temperature measurement visual field position of the radiation thermometer 7 based on the projection position of the light spot radiated from the light projector 14 through the condenser lens 8. The visual field position confirmation jig 15 is made of, for example, an L-shaped plate material such as an L-shaped aluminum on which a cross line 15A and a mark 15B are drawn, as shown in FIGS.
The crosshair 15A is drawn on a translucent plate attached to a circular hole formed in the plate material. The crosshair 15A is set so that the visual field position checking jig 15 is placed on the lower electrode wheel 5B and the lower swaging roll 6B so that the mark 15B coincides with, for example, a straight line (R) passing through the center of the lower electrode wheel 5B. When mounted, the optical axis (L) of the condenser lens 8 is provided at a position passing through the center point of the crosshair 15A.

Reference numeral 16 denotes a multiplexer. The multiplexer 16 and the condenser lens 8, the thermometer main body 10, and the light projector 14 are connected by the optical fiber 9, respectively. According to the seam welding state determination device of the present invention configured as described above, determination of the quality of the welding state of the seam welded portion, and confirmation of the position of the temperature measurement visual field of the radiation thermometer, as described below, Adjustments can be made.

When a determination command is issued from the seam welding controller 13 to the welding state determiner 11, the temperature signal of the seam weld measured by the radiation thermometer 7 is output from the welding state determiner 1.
1, where it is compared with an optimal temperature held by the seam weld when the welding condition is good, which is set in the welding condition determiner 11 in advance. If the comparison result is out of the predetermined range, it is determined that welding is abnormal.

On the other hand, immediately before or immediately after seam welding, when the seam welding machine is retracted outside the continuous strip processing line, as shown in FIGS. 3 and 4, the lower electrode wheel 5B and the lower swaging roll 6B are connected to each other. The visual field position confirmation jig 15 is placed on the lower electrode wheel 5B.
Is placed so as to coincide with the straight line (R). Then, light such as laser light is sent from the light projector 14 to the condenser lens 8 via the multiplexer 16, and the light is transmitted from the condenser lens 8 to the visual field position confirmation jig 15.
Emit light towards. If the light spot deviates from the center point of the cross line 15A of the visual field position confirmation jig 15, the mounting angle of the condenser lens 8 is adjusted so that the light spot coincides with the center point of the cross line 15A. In this manner, the position of the temperature measurement visual field of the radiation thermometer can be easily confirmed and adjusted.

As shown in FIG. 5, when the light spot by the light projector 14 is projected on the screen 17 and the light spot projected on the screen 17 is imaged by the imaging means 18, the visual field deviation of the radiation thermometer 7 from the reference position is obtained. Since the amount can be displayed as an absolute value, it is easier to confirm and adjust the position of the temperature measurement visual field. Further, in this case, since the visual field position checking jig 15 is not required, the visual field position can be confirmed instantaneously when seam welding is not performed.

The image pickup means 18 picks up an image of the screen 17 by the two-dimensional image sensor camera 19, processes this image by the image processing device 20,
This confirms the position of the temperature measurement visual field of the radiation thermometer 7. Two-dimensional image sensor camera 19
May be used instead of an ordinary television camera. In this case, the reference position is marked on the screen 17 and the visual field position is confirmed by looking at the reference position through the television camera.

As shown in FIG. 6, automatic visual field position adjusting means 22 for automatically adjusting the visual field position of the radiation thermometer 7 based on the visual field position data from the imaging means 18 is further provided in the apparatus shown in FIG. Then, the visual field position of the radiation thermometer 7 can be automatically adjusted. Field of view position automatic adjusting means 22
Consists of a position adjuster 24 for freely moving the condenser lens 8 in the horizontal and vertical directions, and a controller 23 for controlling the position adjuster 24 based on image data from the image processing device 20. I have.

[0028]

As described above, according to the present invention,
The useful effect of accurately determining the quality of the welding condition of the seam welded portion and easily confirming and adjusting the position of the temperature measurement visual field of the radiation thermometer for measuring the temperature of the seam welded portion is brought about. It is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a seam welding state determination device according to the first embodiment.

FIG. 2 is a block diagram showing a main part of the seam welding state determination device according to the first embodiment.

FIG. 3 is a schematic perspective view showing an installation state of a visual field position checking jig.

FIG. 4 is a view taken in the direction of arrow A in FIG. 3;

FIG. 5 is a block diagram showing a main part of the seam welding state determination device according to the second embodiment.

FIG. 6 is a block diagram showing a main part of the seam welding state determination device according to the third embodiment.

[Explanation of symbols]

 1: Trailing strip 2: Leading strip 3: Carriage 4: Wheel 5A: Upper electrode wheel 5B: Lower electrode wheel 6A: Upper swaging roll 6B: Lower swaging roll 7: Radiation thermometer 8: Condensing lens 9: Optical fiber 10: Thermometer main body 11: Welding state judgment unit 12: Host computer 13: Seam welding machine controller 14: Floodlight 15: Viewing position confirmation jig 15A: Crosshair 15B: Mark 16: Wave combiner 17: Screen 18: Imaging Means 19: Two-dimensional image sensor camera 20: Image processing device 21: Monitor 22: Field-of-view position automatic adjusting means 23: Controller 24: Position adjuster

Claims (3)

[Claims] The temperature of a seam weld of a preceding strip and a succeeding strip joined by a seam welder is measured in order to determine whether or not the welding state of the seam weld is good. In the seam welding state determination device provided with a radiation thermometer for the, the temperature of the seam weld measured by the radiation thermometer, the welding state of the seam weld set in advance according to welding conditions is good In such a case, the optimum temperature of the seam welded part is compared, and based on the comparison result, a welding state determiner for determining whether the welding state of the seam welded part is good or not, and the seam welding machine is configured to use the continuous metal A light projector for emitting light from the condenser lens of the radiation thermometer when retracted outside the strip processing line; and A seam having a view position confirming function of the radiation thermometer, comprising: a view position confirmation jig for confirming the view position of the radiation thermometer according to the projection position of the light spot radiated through the lens. Welding state determination device. 2. The temperature of the seam weld is measured in order to determine the quality of the seam weld between the preceding strip and the succeeding strip in the continuous metal strip processing line joined by the seam welder. In the seam welding state determination device provided with a radiation thermometer for the, the temperature of the seam weld measured by the radiation thermometer, the welding state of the seam weld set in advance according to welding conditions is good In such a case, the optimum temperature of the seam welded part is compared, and based on the comparison result, a welding state determiner for determining whether the welding state of the seam welded part is good or not, and the seam welding machine is configured to use the continuous metal A light projector for emitting light from the condenser lens of the radiation thermometer when retracted outside the strip processing line; and A screen the light emitted through the lens is projected, in order to confirm the visual field position of the radiation thermometer, characterized by comprising the image pickup means for imaging the light spot projected on the screen,
A seam welding state determination device that has the function of confirming the visual field position of the radiation thermometer. 3. The temperature of the seam weld is measured to determine the quality of the seam weld between the preceding strip and the succeeding strip in the continuous metal strip processing line joined by the seam welder. In the seam welding state determination device provided with a radiation thermometer for the, the temperature of the seam weld measured by the radiation thermometer, the welding state of the seam weld set in advance according to welding conditions is good In such a case, the optimum temperature of the seam welded part is compared, and based on the comparison result, a welding state determiner for determining whether the welding state of the seam welded part is good or not, and the seam welding machine is configured to use the continuous metal A light projector for emitting light from the condenser lens of the radiation thermometer when retracted outside the strip processing line; and A screen onto which the light emitted through the lens is projected, an imaging unit for imaging a light spot projected on the screen to check the visual field position of the radiation thermometer, and visual field position data by the imaging means A seam welding state determination device having a visual field position confirmation function of the radiation thermometer, comprising automatic visual field position adjusting means for automatically adjusting the visual field position of the radiation thermometer based on the following.