JPH0919779A - Diagnostic method and device for laser beam welding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early detect a symptom indicating abnormality of equipment by diagnosing the presence/absence of a positional change of an entrance clamp device on its taper wedge and work side and on the drive side. SOLUTION: First, an amount of vertical travel is measured for a taper wedge 17, which is attached to an entrance clamp device 2, by a position detector 19a, converted to an electric signal by a converter 21a and inputted in a computer 23. The abutting quantity set in the computer 23 is compared with the measured quantity, and then an diagnosis is made for the prescribed positioning of the taper wedge 17 so that a prescribed abutting quantity may be attained. With the entrance clamp device 2 moved to an advancing position, its position is detected by position detectors 19b, 19c, converted to a signal and inputted in the computer 23. Change in the advancing position is diagnosed by the computer 23 for the entrance clamp device 2. Thus, the change in the abutting quantity can be diagnosed for a preceding and succeeding strips 12, 13 at the time of welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility diagnostic method for a laser beam welding apparatus and its apparatus.

[0002]

2. Description of the Related Art Conventionally, as a laser beam welding apparatus used for welding the ends of a leading strip and a trailing strip, for example, a shearing device as disclosed in Japanese Patent Laid-Open No. 4-200986 is integrated. There is one that has been assembled. This laser beam welding device is shown in FIGS. 6 and 7,
In these figures, there is an inlet side clamp device 2 and an outlet side clamp device 3 which are installed at a predetermined interval on a common base 1, and a space between the inlet side clamp device 2 and the outlet side clamp device 3 is seen from the left and right direction. Shear device 4 that can move forward and backward
Further, similarly to this, there is a back bar device 5 that can be moved forward and backward between the inlet side clamp device 2 and the outlet side clamp device 3.

Further, the upper head 6 attached to the upper portion of the outlet clamp device 3 and the upper head 6 in the left-right direction, that is, in the end face direction of the leading strip 12 and the trailing strip 13 which are the materials to be welded and the inlet side. The welding carriage devices 7 and 8 for moving the processing head 9 in the outgoing direction and in the vertical direction between both strip end faces are provided, and the transmission pipe 10 for transmitting the laser beam oscillated by the 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 the conventional laser beam welding apparatus, which is composed of a reflecting mirror 14 for changing the optical path of the laser beam 16 and a condenser lens 15 built in the processing head 9. ing.

Next, the operation of this conventional device will be described. In the steelmaking process line, when the strip is subjected to continuous treatment 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 its end comes,
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 trailing strip 13 has its leading end fed into the blade width 4a of the shearing device 4 and stops. Then, as shown in FIGS. 6 and 9, the back bar device 5 is retracted, and the shear device 4 is advanced to be positioned between the inlet side clamp device 2 and the outlet side clamp device 3.

Then, after the leading and trailing strips 12 and 13 are clamped by the two clamping devices 2 and 3, the shearing device 4 is used.
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 is advanced and positioned between the inlet side clamp device 2 and the outlet side clamp device 3, and then the inlet side clamp device. 2 is moved to the exit side clamp device 3 side by a predetermined amount, the cut surfaces of the leading strip 12 and the trailing strip 13 are butted against each other, and the root gap of the butted portion is controlled to be a given amount.

Then, the two strips 12 and 13 abutted together
The welding carriage devices 7 and 8 are moved in the inlet and outlet directions, that is, in the direction perpendicular to the end faces of both strips 12 and 13 so that the processing head 9 is located on the abutting portion of 1. In this way, after preparing for welding, the transmission pipe
A laser beam 16 oscillated by a laser oscillator 11 via 10 is changed in direction by a reflection mirror 14 and is condensed by a condenser lens 15 at the abutting portion of both strips to start welding. At the same time, the welding carriage device 7 is moved in the left-right direction, that is, in the end face direction of both strips 12 and 13, so that both strips 12 and 13 are continuously welded.

[0007]

However, in the above-mentioned conventional laser beam welding apparatus, welding defects occur in butt welding, and the causes thereof are as follows. When actual values such as laser output and traveling speed of the processing head deviate from the set values. When the mechanical accuracy of the input / output side clamp device, shear device, back bar device, etc. changes or oil leaks from the actuator.

[0008] Therefore, as measures against these, first, various kinds of judgment and diagnosis methods mainly based on the monitoring have been proposed for judging abnormalities such as laser output and traveling speed of the processing head. However, there is currently no suitable countermeasure for changes in the mechanical accuracy of each device, and each time the operating process line is stopped, the device is disassembled, the device is disassembled and inspected and measured in detail, and the defective part is repaired. It is the actual situation.

Therefore, if a welding failure due to the abnormal factor is not detected, the welded strip meanders in the process line or a fracture occurs at the welded portion, and the process line must be stopped for a long time. , If the abnormal state occurs for a long time,
Operational losses will be severe. Therefore, in order to solve the above problems, (a) obtaining information for each continuous welding, (b) clarifying the cause of the difference in the amount of butt, (c) the amount of butt It is necessary to investigate such things as accurately detecting the difference between the two, and (d) clarifying the relationship between the change in the amount of butt and the quality of the weld.

Of the above, as for (a), (b) and (d), a method for elucidating or monitoring has already been established, but a method for accurately detecting the difference in the amount of butting in (c) has been established conventionally. Therefore, even if an abnormality occurs in the device, the abnormality cannot be detected early and a quick response cannot be taken. The present invention has been proposed in order to solve the above problems of the conventional technology,
An object of the present invention is to provide a method for diagnosing equipment for a laser beam welding device and a device therefor capable of determining whether or not there is a position change between an advancing position and a retracting position of an entrance side clamping device.

[0011]

According to the present invention, a tail end portion of a leading strip and a leading end portion of a trailing strip are cut and abutted, and welded while being clamped by an output side clamping device and an input side clamping device, respectively. In a method of diagnosing the presence or absence of a mechanical error of equipment in a laser beam welding device, a moving amount of a taper wedge that determines an advancing position of the entrance side clamping device is measured in a direction perpendicular to a traveling direction of the strip, and Comparing the butt amount converted based on the measured value with a preset butt amount, and diagnosing whether or not the inlet clamp device has stopped at a predetermined position; and the inlet clamp By measuring the positions on the work side and the drive side when the device has moved to the forward position, it is possible to check whether there is a change in the forward position of the input side clamping device. And a step of measuring the positions on the work side and the drive side in a state in which the entrance side clamping device is in a standby position at the retracted position, and diagnosing whether or not there is a change in the retracted position of the entrance side clamping device. A method for diagnosing equipment for a laser beam welding apparatus, characterized in that

Further, according to the present invention, the tail end portion of the leading strip and the leading end portion of the trailing strip are cut and abutted,
In a device for diagnosing the presence or absence of a mechanical error in equipment in a laser beam welding device that performs welding while clamping each with an outgoing side clamp device and an incoming side clamp device, an end portion of a taper wedge that determines the forward position of the incoming side clamp device And a position detector attached to the input side clamping device to detect the position of the taper wedge, and a position detector attached to the work side and the drive side of the input side clamping device to detect the positions of the advancing position and the retracted position of the input side clamping device. And a computer for inputting an electric signal from the position detector and diagnosing whether or not there is a change in the forward and backward positions of the entrance side clamp device. It is a diagnostic device.

[0013]

According to the present invention, position detectors are attached to the taper wedge, the work side and the drive side of the entrance side clamp device to diagnose the presence or absence of position changes of the entrance side clamp device in the forward and backward positions. Therefore, when the position change occurs in the entrance side clamp device, it is possible to quickly detect the position change.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1A and 1B are a side view and a plan view, respectively, showing an advancing state of an inlet side clamping device according to an embodiment of the present invention, and FIG. 2 similarly shows a retracted state of the inlet side clamping device. It is a side view and the (b) top view. In the drawings, the same members as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, reference numeral 17 denotes a taper wedge that determines the forward position of the entrance side clamping device 2 and is horizontally attached to the lower part of the entrance side clamping device 2. Reference numeral 18 is an operating arm for operating the taper wedge 17. 19a-19c
Is a position detector of a type provided on the taper wedge 17 side, the work side (WS), and the drive side (DS) of the entrance side clamp device 2 for detecting a change in magnetic resistance at a rod position, for example. Reference numerals 20a to 20c are connection members for mechanically connecting the position detectors 19a to 19c. Reference numerals 21a to 21c are converters provided corresponding to the respective position detectors 19a to 19c, and the position detectors 19a to 19c transmitted via the signal lines 22a to 22c.
The detection signal from c is converted into an electric signal. Reference numeral 23 is a computer, which receives the electric signals from the converters 21a to 21c via the signal lines 24a to 24c and performs the arithmetic processing described later. Reference numeral 25 denotes a display, which displays the result calculated by the computer 23 via the signal line 26. 27 is a stopper.

Therefore, first, the position detector 19a measures the vertical movement amount of the taper wedge 17 attached to the inlet side clamp device 2 through the connecting member 20a in the vertical direction indicated by the arrow B, and then through the signal line 22a. Then, it is converted into an electric signal by the converter 21a and input to the computer 23 through the signal line 24a.
As a result, in the computer 23, a predetermined butted amount set in advance is compared with the butted amount converted by calculation using the moving amount of the taper wedge 17 measured by the position detector 19a, and the given butted amount is calculated. It is possible to diagnose whether or not the taper wedge 17 is positioned at a predetermined position so that

Next, the entrance side clamping device 2 is moved to the forward position F.
Moved to P (leading strip 12 and trailing strip)
Position detector 19 with 13 welded together.
b, 19c detects the forward position FP of the inlet side clamp device 2 via the connecting members 20b, 20c, and the signal lines 22b, 22c
The converter 21b, 21c converts the detection signal via
Input to the computer 23 via the signal lines 24b and 24c. Thereby, in the computer 23, the change in the forward movement position FP of the entrance side clamping device 2 can be constantly diagnosed as described above.

Next, referring to FIG. 2, with the entrance side clamp device 2 standing by at the retracted position BP, the position detectors 19b,
19c detects the retracted position BP of the inlet side clamp device 2 through the connecting members 20b and 20c and performs arithmetic processing in the computer 23, so that a change in the retracted position BP of the inlet side clamp device 2 can be constantly diagnosed. . Hereinafter, an example to which the device of the present invention configured as described above is applied will be described.

As the position detector 19a, one having a specification of a measuring range of 100 mm is applied according to the stroke of the taper wedge 17 of 60 mm. The measurement accuracy of this position detector 19a is 0.01mm
It is. Further, as the position detectors 19b and 19c, those having a specification of a measurement range of 500 mm are applied in accordance with the forward / backward stroke 400 mm of the entrance side clamp device 2. Its measurement accuracy is 0.01 mm. In this case, in order to mechanically connect the device main body of the inlet side clamp device 2 and the position detectors 19b and 19c, the connecting members 20b and 20c were attached to the device main body of the inlet side clamp device 2.

First, the taper wedge 17 moves in the direction of the arrow B in FIG. 1 to position the forward position FP of the entrance side clamping device 2, but the leading strip 12 and the trailing part when laser beam welding are performed. The command value RG _SV of the abutting amount of the strip 13 (hereinafter referred to as the root gap) and the moving amount L _W of the taper wedge 17 have the relationship of the following equation (1).

L _W = RG _SV / T _P (1) Here, T _P represents the reciprocal of the slope of the inclined surface of the tapered wedge 17. Further, in this embodiment, in order to make the relationship between the route gap command value RG _SV and the movement amount L _W of the taper wedge 17 easy to understand, the above equation (1) is modified to derive the following equation (2). According to formula (2), taper wedge 17
The route gap conversion value RG _RV is calculated from the movement amount L _{W of}

RG_RV= L_W・ T_P ……………… (2) And this route gap conversion value RG_RVFrom rootgi
Up command value RG_SVIs subtracted to convert the route gap
RG_RVAnd route gap command value RG_SVDeviation amount from
_iAnd the standard deviation amount ΔRG set in advance_SV
And deviation amount ΔRG _iAnd perform a comparison operation.

ΔRG_i= RG_RV-RG_SV ……………… (3) An example of this diagnosis is shown in Fig. 3. The vertical axis in the figure is the route gap
Converted value RG_RVThe horizontal axis indicates the route gap command value R
G_SVIs shown. The solid line in this figure is RG _SV= RG
_RVThe straight line indicates the measured value.
I have. Also, the two dashed lines above and below the solid line in the figure
Route gap command value RG_SVRoot gap replacement for
Calculated value RG_RVShows the allowable range of the variation. This meter
As in the measurement example, the operation for the command value of the taper wedge 17
The condition can be quantitatively grasped by this diagnosis.

Next, FIG. 4 shows the measured value of the forward movement position FP of the entrance side clamping device 2. This measurement is performed by the position detectors 19b and 19c provided on the work side (WS) and the drive side (DS) of the input side clamp device 2, respectively. The vertical axis in this figure shows the difference between the measured value and the command value of the forward movement position FP in the entry side clamp device 2, and the horizontal axis shows the data number of the measured signal. The reference position in the figure is the measured value of the forward position FP =
The position of the command value is shown, and the white circle mark ◯ shows the work side (WS) of the input side clamp device 2 and the square mark □ shows the measured value of the drive side (DS). In this case, the upper and lower limit values of the allowable variation in the difference between the measured value of the forward movement position FP of the entry side clamp device 2 and the command value are indicated by the alternate long and short dash line.

As shown in this measurement example, the difference in the measured value with respect to the command value of the forward position FP of the inlet side clamp device 2 is analyzed by a trend graph for each welding, so that the mechanical accuracy of the inlet side clamp device 2 is improved. Can be quantitatively diagnosed, and by simultaneously analyzing the difference between the measured value and the command value of the forward position of the work side and the drive side of the entry side clamp device 2, the abutting of the leading and trailing strips 12 and 13 at the time of welding Changes in quantity can be diagnosed.

Next, FIG. 5 shows an example of measurement of the retracted position BP of the entrance side clamp device 2. This measurement is performed by the position detectors 19b and 19c provided on the work side and the drive side of the entry side clamp device 2, respectively. In this figure, the vertical axis represents the measured value of the retracted position BP of the entry side clamp device 2, and the horizontal axis represents the data number for each welding. Also, the alternate long and short dash line in the figure indicates the upper and lower limit values of the allowable range of variation of the retracted position BP of the entrance side clamp device.

As in this measurement example, the inlet side clamp device 2
Has a mechanical structure in which the retreat position BP of the entrance side clamp device 2 is always a fixed position when it is waiting at the retreat position BP. The retracted position B of the entry side clamp device 2
If P changes while waiting for the retracted position, when cutting the leading and trailing strips 12 and 13 by the shear device 4, the cutting position changes in the moving direction of the strip, so that the root gap of the abutting portion during welding changes. Since the welding quality is deteriorated, the measurement of the retracted position BP of the entry side clamp device 2 is also an important control point.

As in the measurement example of FIG. 5, by measuring the retracted position BP of the entrance side clamping device 2, the above-mentioned FIG.
In the same manner as in the above case, the mechanical accuracy of the entrance side clamp device 2 can be quantitatively diagnosed.

[0029]

As described above, according to the present invention,
Since the position detectors are attached to the taper wedge, work side and drive side of the input side clamp device to check the presence or absence of each position change of the input side clamp device in the forward and backward positions, If a displacement occurs in the device, it can be detected quickly. With this, it is possible to detect the sign indicating the device abnormality at an early stage, and it is possible to quickly correct the defect of the device, and thus it is possible to significantly reduce the occurrence of meandering of the strip and breakage of the weld portion. is there. Also,
Since it is possible to achieve stable operation as a qualitative effect, it is effective in reducing operating costs.

[Brief description of the drawings]

FIG. 1A is a side view and FIG. 1B is a plan view showing an advancing state of an entrance side clamping device according to an embodiment of the present invention.

FIG. 2A is a side view and FIG. 2B is a plan view showing a retracted state of the entrance side clamping device according to the embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a root gap command value and a root gap conversion value.

FIG. 4 is a characteristic diagram showing data of a difference between a measured value and a command value of a forward movement position of the entry side clamp device.

FIG. 5 is a characteristic diagram showing measurement data of a retracted position of the entry side clamp device.

FIG. 6 is a perspective view showing an operating state of a conventional laser beam welding position.

FIG. 7 is a perspective view showing an operating state of a conventional laser beam welding position.

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

FIG. 9 is an explanatory diagram of an operating state of a conventional laser beam welding position.

FIG. 10 is an explanatory diagram of an operating state of a conventional laser beam welding position.

[Explanation of symbols]

 1 Common Base 2 Inlet Clamping Device 3 Outlet Clamping Device 4 Shear Device 5 Back Bar Device 6 Upper Head 7,8 Welding Carriage Device 9 Processing Head 10 Transmission Tube 11 Laser Oscillator 12 Leading Strip 13 Trailing Strip 14 Reflecting Mirror 15 Optical lens 16 Laser beam 17 Tapered wedge 18 Working arm 19a to 19c Position detector 20a to 20c Connection member 21a to 21c Converter 22a to 22c, 24a to 24c, 26 Signal line 23 Computer 25 Display 27 Stopper WS Work side DS drive Side FP Forward position BP Reverse position

Claims (2)

[Claims] 1. A machine of equipment in a laser beam welding device, in which a tail end of a preceding strip and a tip of a trailing strip are cut and abutted, and welded while being clamped by an output side clamping device and an input side clamping device, respectively. In the method of diagnosing the presence or absence of a physical error, the amount of movement of the taper wedge that determines the forward position of the entrance side clamping device in the direction perpendicular to the traveling direction of the strip is measured, and converted based on this measurement value. A step of comparing the amount of abutment with a preset amount of abutment to diagnose whether or not the inlet side clamp device has stopped at a predetermined position, and the inlet side clamp device has moved to the forward position. Measuring the positions on the work side and the drive side in the state, and diagnosing whether or not there is a change in the forward movement position of the input side clamping device; A step of measuring the positions on the work side and the drive side in a state where the lamp device is standing by at the retracted position, and diagnosing whether or not there is a change in the retracted position of the input side clamping device. Beam welding equipment facility diagnosis method. 2. A machine of equipment in a laser beam welding device, which cuts a tail end portion of a leading strip and a leading end portion of a trailing strip, but abuts them, and then welds them while clamping each with an outgoing side clamping device and an incoming side clamping device. In a device for diagnosing the presence or absence of a physical error, a position detector attached to an end of a taper wedge that determines a forward position of the entrance side clamp device and detecting a position of the taper wedge, and a work side of the entrance side clamp device And a position detector attached to the drive side for detecting the positions of the entrance side clamping device in the forward movement position and the backward movement position, and the forward position and the backward movement position of the entrance side clamping device by inputting an electric signal of the position detector. And a computer for diagnosing whether or not there is a change in position in the laser beam welding equipment facility diagnosis apparatus.