JP3690491B2 - Welding control system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding control system such as carbon dioxide arc welding.
[0002]
[Prior art]
After the Great Hanshin Earthquake, attention has been paid to the quality of welds in steel structures, and the concept of quality required for welds has changed, and methods for ensuring better quality are being sought. In general, the quality of a welded portion is confirmed by detecting internal defects by visual inspection and nondestructive inspection.
[0003]
[Problems to be solved by the invention]
However, internal defect detection by the above-described conventional visual inspection and nondestructive inspection is troublesome and inefficient, and there is a problem that it is not easy to apply to existing buildings. It is requested.
In carbon dioxide arc welding or the like, process management based on welding conditions can be considered as one method for obtaining good quality of the welded portion. Here, the welding conditions are called heat input and interpass temperature. The heat input is the input energy at the time of welding represented by a value obtained by dividing the product of current and voltage by the welding speed (current × voltage / welding speed), and the interpass temperature is the surface temperature of the base material immediately before welding. Despite the great influence on the mechanical properties of the weld zone, the welding conditions often depend on the skill and intuition of the operator under the conventional quality control system and are not always satisfactory.
[0004]
The present invention has been made in view of such a conventional situation, and in the case of carbon dioxide arc welding or the like, the welding conditions at the time of welding construction are automatically measured without depending on the skill and intuition of the operator, and based on this. It is an object of the present invention to provide a welding control system capable of improving and managing welding quality.
[0005]
[Means for Solving the Problems]
As specific means for achieving this object, the present invention includes a step of starting a welding program, a step of inputting numerical values such as a welding length of a welded portion, a step of starting welding construction, and welding condition analysis. The steps of automatically measuring each value such as current, voltage, interpass temperature, arc time, etc. required for the calculation, calculating the heat input from these measured values, and comparing the heat input and interpass temperature with the reference value If the heat input and the temperature between passes have cleared the reference value, the step to continue welding work after the next pass and the heat input will clear the reference value, but the temperature between passes has become too high In this case, the power supply is forcibly stopped until the temperature reference is cleared, and if the reference values for both heat input and interpass temperature cannot be cleared, the administrator is notified and the future action is considered. The welding control system including bets it is an gist.
[0006]
The present invention can automatically measure and analyze the welding conditions during welding, thereby controlling the welding operation and ensuring good quality of the welded portion.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment in which the present invention is applied to carbon dioxide arc welding of a steel frame will be described with reference to the accompanying drawings. FIG. 1 shows the flow of the welding control system. First, the welding optimum control program is started (step S0), and in the first step S1, numerical values such as the plate width (flange width) of the welded portion by the manager are obtained. Entered. By dividing the numerical value such as the plate width by the arc time that is automatically measured later, the welding speed necessary for the heat input calculation can be calculated.
[0008]
Next, welding is started in the second step S2, and current, voltage, interpass temperature, arc time (time required for one pass), etc. are automatically measured in the third step S3 based on the welding start situation. . Based on this measured value, heat input is calculated in the fourth step S4.
[0009]
In the fifth step S5, the heat input and the interpass temperature obtained by calculation are compared with a reference value that has been input and stored in advance, and the subsequent action is controlled. In other words, if both the heat input and interpass temperature clear the reference value (YES), welding is continued after the next pass, and the heat input clears the reference value but the interpass temperature becomes too high. (NO) stops the current in the sixth step S6, and then compares the interpass temperature with the predetermined temperature in the seventh step, and if satisfied (YES), starts the welding work, If not satisfied (NO), the process returns to the sixth step S6, and the current stop is continued until the predetermined temperature is reached. If the reference values for both heat input and interpass temperature cannot be cleared (NO), the manager is notified in the eighth step S8 and the future countermeasures are examined.
[0010]
Thus, by automatically measuring and analyzing the welding conditions, it is possible to autonomously control the welding operation, ensure the quality of the welded portion, and perform the welding operation efficiently. In addition, although the said embodiment demonstrated by the example of the carbon dioxide arc welding, this invention is applicable not only to this but to various welding.
[0011]
【The invention's effect】
As described above, according to the present invention, current, voltage, interpass temperature, arc time, etc. are automatically measured during welding, and heat input is calculated based on the measured values. Since the welding operation is controlled by comparing with the reference value, it is possible to perform an appropriate welding operation without depending on the skill and intuition of a conventional worker. Therefore, the present invention can provide the following excellent effects.
(1) The quality of the weld is stable.
(2) Inspection labor necessary for ensuring welding quality can be reduced.
(3) Can flexibly respond to changes in welding conditions.
(4) Welding quality control system can be established.
(5) The welding efficiency can be improved while ensuring the welding quality.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an embodiment of a welding control system according to the present invention.
[Explanation of symbols]
S0 ... Program start S1 ... First step S2 ... Second step S3 ... Third step S4 ... Fourth step S5 ... Fifth step S6 ... Sixth step S7 ... Seventh step S8 ... Eighth Steps

Claims (1)

Steps for starting the welding program, inputting numerical values such as the weld length of the weld, starting the welding process, current, voltage, interpass temperature, arc time, etc. required for welding condition analysis The step of automatically measuring the value, the step of calculating the heat input from these measured values, the step of comparing the heat input and interpass temperature with the reference value, and the heat input and interpass temperature cleared the reference value. If this is the case, continue the welding process after the next pass and the heat input will clear the reference value, but if the temperature between passes is too high, the power supply will be forcibly stopped until the temperature reference is cleared. And a step of notifying the manager and considering future measures when both the heat input and interpass temperature cannot be cleared, a welding control system.

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