JPH10244383A - Method and device for diagnozing clamp device of laser beam welding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent breakage of a weld zone in advance by detecting the deflection of outlet side and inlet side clamp devices in the plate width direction, and outputting an abnormal alarm when the deflection exceeds the preset reference value to rapidly detect generation of the level difference between a butted part of a preceding strip and of a succeeding strip. SOLUTION: When a rear end part of a preceding strip 12 is fixed by upper and lower clamp pads 17, 18 of an outlet side clamp device 3, the deflection in the plate width direction of a rear pad piece 18b is detected by a displacement meter 29a, the detected signal is transmitted to converters 32a-32d through signal lines 31a-31d, the converted signal is transmitted to a relay panel 34 through signal lines 33a-33d, and the signal is transmitted to an operation device 36 through a signal line 35. The difference between the minimum value and the maximum value of the deflection in the plate width direction of a rear pad piece 18b is calculated, the difference is compared with the preset reference value, and an abnormal alarm is displayed on a display device 43 when the difference exceeds the reference value. Similar operation is performed even by an inlet side clamp device 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of diagnosing a clamping device of a laser beam welding machine and an apparatus therefor.

[0002]

2. Description of the Related Art Generally, in a continuous process line, a leading strip (hereinafter, referred to as a preceding strip) and a succeeding strip (hereinafter, referred to as a following strip) are joined together at their ends to be continuous. Predetermined processing is performed in each process line.
Such bonding is usually performed using a process line welder. That is, after the tail end of the preceding strip and the leading end of the following strip are cut by the shear device provided in the process line welder, the tail end and the leading end are butted against each other, and the butt groove is formed. This is done by laser beam welding or flash butt welding along the line, or by resistance welding in which the tail end portion and the tip end portion are vertically overlapped and sandwiched between electrodes for welding.

Here, for example, a conventional laser beam welding apparatus will be described with reference to JP-A-63-52787. As shown in FIGS. 6 and 7, entrance and exit clamp devices 2 and 3 are provided on the common base 1 at a predetermined interval, and a gap between the entrance and exit clamp devices 2 and 3 is provided. A shear device 4 that can move back and forth from the left and right directions, and a back bar device 5 that can move back and forth from the left and right directions are respectively installed between the shear device 4 that can move back and forth from the left and right sides and the clamping devices 2 and 3 on the ingress side.

Further, an upper head 6 is mounted on the upper portion of the output side clamping device 3, and the upper side of the upper head 6 is moved in the left-right direction, that is, in the direction of both end faces of the strip and on the entrance side.
Welding carriages 7 and 8 for moving the processing head 9 in the exit direction and vertically between both strip end faces are provided, and a transmission tube 10 for transmitting a laser beam oscillated from a laser oscillator 11 is provided. Here, the arrow A indicates the moving direction of the following strip 13. FIG. 8 shows an optical system of a laser beam used in the laser beam welding apparatus. The reflecting mirror 14 for changing the optical path of the laser beam 16 and the condenser lens 15 built in the processing head 9 are shown. It is composed of

Next, the operation of the conventional device will be described. In the steelmaking process line, when the strip is subjected to continuous processing such as pickling, plating, and heat treatment, the strip travels in the direction indicated by arrow A in FIG. And when the strip is sent and comes to the end,
The leading strip 12 is guided into the blade width 4a of the shear device 4 and stops as shown in FIG. In this state, the leading end of the trailing strip 13 is fed into the blade width 4a of the shear device 4 and stops. Then, as shown in FIGS. 6 and 9, the back bar device 5 retreats, and the shear device 4 moves forward and is positioned between the entrance-side clamp device 2 and the exit-side clamp device 3.

Then, the leading end of the preceding strip 12 is clamped by the upper and lower clamp pads 17 and 18 of the output side clamp device 3, and the succeeding strip 13 is clamped by the upper and lower clamp pads 19 and 20 of the entrance side clamp device 2. Later, shear device 4
The upper shear blade descends to cut the opposing ends of both strips 12,13. Subsequently, as shown in FIGS. 7 and 10, the shear device 4 is retracted, the back bar device 5 moves forward and is positioned between the entrance-side clamp device 2 and the exit-side clamp device 3, and then the entrance-side clamp device The apparatus 2 is moved to the exit side clamp apparatus 3 by a predetermined amount, the cut surfaces of the preceding strip 12 and the following strip 13 are butted, and the root gap of the abutting portion is controlled to be a predetermined amount.

Next, the butted strips 12, 13
The welding carriages 7 and 8 are moved in the entry and exit directions, that is, at right angles to the end faces of the strips 12 and 13 so as to position the machining head 9 on the butting portion of the strips 12 and 13 to control the position. After the welding preparations have been prepared in this way, the laser beam 16 oscillated by the laser oscillator 11 is changed in direction by the reflection mirror 14 through the transmission pipe 10 as shown in FIG. As a result, the welding is started by focusing the light on both strip butting portions, and the welding carriage device 7 is moved in the left-right direction,
Move both strips 1 by moving
Weld 2, 13 continuously.

[0008]

However, the following points can be cited as causes of poor welding in butt welding in the above-mentioned conventional laser beam welding apparatus. In other words, if the actual values such as the laser output and the traveling speed of the processing head deviate significantly from the set values, the mechanical accuracy of the input-side clamp device, output-side clamp device, shear device, back bar device, etc. changes, For example, when oil leakage occurs.

As a countermeasure against these problems, various determination and diagnosis methods have been proposed for abnormality determination in the above case, mainly for monitoring the abnormality. However, in the case of the above, there is no appropriate countermeasure, and in each case, the operating process line is stopped, and the relevant equipment is disassembled and inspected and measured in detail.
At present, repairs are performed after confirming defective parts.

[0010] Further, when a welding defect due to the above-mentioned abnormal factor is detected, the welded strip meanders in the process line or the welded portion of the strip breaks, and the process line must be stopped for a long time. In addition, there is a possibility that if the abnormal condition continues for a long time, the operation may be greatly damaged. Therefore, in order to solve the above-mentioned problems, (a) to obtain information for each continuous welding, (b) to clarify the causes of the step difference at the butt of the strip, (c) Elucidating the causal relationship between the change in the butted amount of the strip and the quality of the welded part, (d) accurately detecting the step at the butted part, and (e) means and equipment for minimizing the step at the butted part. And other measures are required.

Among the above, as for (a), (b) and (c), the elucidation or monitoring method has already been established, but the step of the abutting portion in (d) and (e) is detected with high accuracy. The method has not been established so far, so even if a laser beam welding machine abnormality occurs, it is possible to detect the abnormality in the step at the abutting part between the strips at an early stage and respond quickly. There was no.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and detects a step of an abutting portion with high accuracy to quickly cope with the problem. It is an object of the present invention to provide a method of diagnosing a clamp device of a laser beam welding machine and a device for preventing a welded portion from breaking.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a method of diagnosing the exit and entry clamps of a laser beam welder for welding opposite ends of a leading strip and a trailing strip. Detecting the amount of deflection in the plate width direction of the entry-side clamp device using a plurality of displacement meters, obtaining a difference between the obtained deflection amounts, and performing a comparison operation with a preset reference amount, and a deflection amount. And a step of outputting an abnormal alarm when the difference between the two exceeds a reference amount.

The present invention also provides an apparatus for diagnosing an outgoing side and an incoming side clamping device of a laser beam welding machine for welding both opposing ends of a preceding strip and a following strip.
A plurality of displacement meters arranged in the plate width direction of the output side clamp device and the entrance side clamp device, and a difference between the amount of deflection in the plate width direction detected by the displacement meter is determined and compared with a predetermined reference amount. A calculation device that calculates and determines whether the difference in the amount of deflection exceeds the reference amount, and a display device that displays an abnormal alarm when the difference exceeds the reference amount, the laser beam welding machine comprising: This is a diagnostic device for the clamp device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment according to the present invention, and FIG.
It is an X arrow view. In these drawings, the same members as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, the output side clamping device 3
The upper clamp beam 22 and the lower clamp beam 23 supporting the upper and lower clamp pads 17 and 18 on the output clamp base 21, the upper clamp beam 22 via the rod 24a. And four hydraulic cylinders 24, for example, which operate to move up and down. The upper clamp pad 17 is divided into two front and rear parts and includes a front pad piece 17a and a rear pad piece 17b. Similarly, the lower clamp pad 18 is also composed of a front pad piece 18a and a rear pad piece 18b.

The entry-side clamp device 2 includes an entry-side clamp base 25 and an upper clamp beam 26 that supports a pair of upper and lower clamp pads 19 and 20 on the entry-side clamp base 25.
And lower clamp beam 27 and upper clamp beam 26
The upper clamp pad 19 and the lower clamp pad 20 also have front pad pieces 19a, respectively.
It is composed of a rear pad piece 19b, a front pad piece 20a, and a rear pad piece 20b.

In the width direction below the rear pad piece 18b of the lower clamp pad 18 of the output side clamp device 3 and in the width direction below the front pad piece 20a of the lower clamp pad 20 of the input side clamp device 2, for example, Four non-contact or contact displacement meters 29a, 29b, 29c, 29d and
30a, 30b, 30c, 30d are installed at equal intervals with a distance L, and the rear pad piece 18b and the front pad piece 20a, respectively.
The degree of displacement in the width direction is measured.

Displacement gauges 29a, 29 on the output side clamping device 3 side
b, 29c, 29d are signal lines 31a, 31b, 31c, respectively.
Converters 32a, 32b, 32c, 32d are connected via 31d, and converters 32a, 32b, 32c, 32d are respectively signal lines.
It is connected to the relay board 34 via 33a, 33b, 33c, 33d. The relay board 34 is connected to an arithmetic unit 36 by a signal line 35. On the other hand, the displacement gauges 30a, 30b, 30c, 30d on the entrance side clamp device 2 side are signal lines 37a, 37d, respectively.
Converters 38a, 38b, 38c, 38d via b, 37c, 37d
And the converters 38a, 38b, 38c, 38d are connected to the relay panel 40 via signal lines 39a, 39b, 39c, 39d, respectively. The relay board 40 is connected to the arithmetic unit 36 by a signal line 41. The arithmetic unit 36 is connected to a display device 43 such as a CRT via a signal line 42.

Therefore, when the rear end of the preceding strip 12 is clamped and fixed by the upper and lower clamp pads 17, 18 of the output side clamping device 3, the amount of deflection of the rear pad piece 18b in the plate width direction is measured by a displacement meter. 29a, 29b, 29c, 29d, and the detection signal is transmitted to converters 32a, 32b, 32c, 32d via signal lines 31a, 31b, 31c, 31d.
The signal is converted by 32a, 32b, 32c, 32d and the signal line 33a,
The signal is transmitted to the relay board 34 via 33b, 33c, 33d, and further transmitted from the relay board 34 to the arithmetic unit 36 via the signal line 35. Then, the arithmetic unit 36 calculates the difference between the minimum value and the maximum value of the deflection amount of the rear pad piece 18b in the plate width direction, that is, the difference in the deflection amount in the plate width direction, and calculates the difference between the deflection amount and the arithmetic unit in advance. Comparison with the reference amount set in 36 is performed, and when the difference in the amount of deflection exceeds the reference amount, the state is output and displayed on the display device 43 via the signal line 42, and an alarm is issued to the operator. Emit.

Similarly, when the leading end of the trailing strip 13 is clamped and fixed by the upper and lower clamp pads 19, 20 of the entry-side clamp device 2, the amount of deflection of the front pad piece 20a in the plate width direction is measured by the displacement meter 30a. , 30b, 30c, 30d, and the detected signals are sent to signal lines 37a, 37b, 37c, 37d.
Are transmitted to the converters 38a, 38b, 38c, 38d via the converter, and are converted into signals by the converters 38a, 38b, 38c, 38d.
a, 39b, 39c, and 39d are transmitted to the relay panel 40, and further transmitted from the relay panel 40 to the arithmetic unit 36 via the signal line 41. Then, in the arithmetic unit 36, the front pad piece 20a
The difference in the amount of deflection in the plate width direction is calculated, and this difference in the amount of deflection is compared with a reference amount preset in the arithmetic unit 36.If the difference in the amount of deflection exceeds the reference amount, The state is output and displayed on the display device 43 via the signal line 42,
Alert the operator.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An application example of the present invention will be described below.
Four non-contact displacement gauges each having a thickness of 400 mm are arranged in the width direction below the rear pad piece 18b of the output side clamp device 3 and in the width direction below the front pad piece 20a of the entrance side clamp device 2 respectively.
Mounted at intervals. The measurement range of the amount of deflection was 0 to 5 mm from past measurement cases. The reference value of the difference in the amount of deflection was set to 0.1 mm as the maximum range in which the step of the butted portion did not become abnormal for both the rear pad piece 18b and the front pad piece 20a.

FIGS. 3 and 4 show that the plate width is 1200 mm and the plate thickness is
This shows an example of the distribution of the amount of deflection in the plate width direction when the 3.2 mm preceding strip 12 and the succeeding strip 13 are clamped. Indicated by. In each case, the measurement points 2 and 3 near the center are larger than the measurement points 1 and 4 near both ends. Further, according to FIG. 3, it can be seen that the difference in the amount of deflection is smaller than the reference amount and that the state is normal. On the other hand, according to FIG. 4, it can be seen that the difference in the amount of deflection is larger than the reference amount, indicating that the state is abnormal.

FIG. 5 shows the maximum value of the difference in the amount of deflection in the arithmetic unit 36 based on the measurement results of FIGS. The data unit 11 was in the normal state up to the data number 11, but the data unit 12 to 16 exceeded the reference amount of 0.1 mm, indicating an abnormal state. Therefore, the operator determined that an abnormality occurred in the step of the butted portion, and repaired the output side clamping device 3 and the entrance side clamping device 2. As a result, the data No. 17 and later returned to the normal state.

[0025]

As described above, according to the present invention,
The amount of deflection in the plate width direction of the output side clamping device and the entrance side clamping device is detected using a displacement meter, the difference in the amount of deflection is determined and compared with a preset reference amount. Since an abnormality alarm is output, the occurrence of a step at the abutting portion between the preceding strip and the following strip can be detected immediately, and the welding quality of the laser beam welding machine can be improved. As a result, breakage of the welded portion can be prevented beforehand, which contributes to stabilization of the line operation and has an excellent effect of reducing the operation cost.

[Brief description of the drawings]

FIG. 1 is a side view showing a main part of an embodiment according to the present invention.

FIG. 2 is a view as viewed in the direction of arrows XX in FIG. 1;

FIG. 3 is a characteristic diagram showing a deflection amount in a plate width direction.

FIG. 4 is a characteristic diagram showing a deflection amount in a plate width direction.

FIG. 5 is a characteristic diagram illustrating time-series data of the maximum value of the difference in the amount of deflection.

FIG. 6 is a perspective view showing an operation state of a conventional laser beam welding apparatus.

FIG. 7 is a perspective view showing an operation state of a conventional laser beam welding apparatus.

FIG. 8 is an explanatory diagram of an optical path of a laser beam.

FIG. 9 is an explanatory diagram of an operation state of a conventional laser beam welding apparatus.

FIG. 10 is an explanatory diagram of an operation state of a conventional laser beam welding device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Common base 2 Inlet side clamp device 3 Outlet side clamp device 5 Back bar device 6 Upper head 7, 8 Welding carriage 9 Processing head 10 Transmission tube 11 Laser oscillator 12 Leading strip 13 Trailing strip 14 Reflection mirror 15 Condenser lens 16 Laser Beam 17, 19 Upper clamp pad 17a, 18a, 19a, 20a Front pad piece 17b, 18b, 19b 20b Rear pad piece 18, 20 Lower clamp pad 21 Outgoing clamp base 22, 26 Upper clamp beam 23, 27 Lower clamp Beam 24, 28 Hydraulic cylinder 24a, 28a Rod 25 Inlet clamp base 29a, 29b, 29c, 29d, 30a, 30b, 30c, 30d Displacement meter 31a, 31b, 31c, 31d, 33a, 33b, 33c, 33d Signal line 32a, 32b, 32c, 32d, 38a, 38b, 38c, 38d Transducers 34, 40 Relay boards 35, 37a, 37b, 37c, 37d, 39a, 39b, 39c, 39
d, 41, 42 signal line 36 arithmetic unit 43 display unit

Claims (2)

[Claims] 1. A method for diagnosing an outgoing and incoming clamping device of a laser beam welding machine for welding both opposite ends of a leading strip and a following strip, comprising: Detecting the amount of deflection in the direction using a plurality of displacement meters;
Determining a difference between the obtained deflection amounts and performing a comparison operation with a preset reference amount, and outputting an abnormality alarm when the difference between the deflection amounts exceeds the reference amount. Diagnosis method for clamping device of laser beam welding machine. 2. A device for diagnosing an outgoing and incoming clamping device of a laser beam welding machine for welding both opposite ends of a leading strip and a following strip, comprising: A plurality of displacement gauges arranged in the direction, the difference in the amount of deflection in the plate width direction detected by the displacement meter is calculated and compared with a predetermined reference amount, and whether the difference in the amount of deflection exceeds the reference amount A diagnostic device for a clamp device of a laser beam welding machine, comprising: an arithmetic device for determining whether or not the current value is a reference value;