KR101860947B1 - Welding Arc Regeneration Expectation Method for Reduction Spatter - Google Patents

Abstract

The present invention relates to a welding arc regeneration predicting method for reducing the spatter so as to predict the regeneration of the arc in advance so as to improve the welding quality by reducing the spatter generated during welding.
The present invention comprises a step (S1) of measuring a welding voltage while performing welding; (S2) comparing the current welding voltage value after the step (S1) with a predetermined short-circuit voltage value; If the welding voltage after step S2 is less than or equal to the short-circuit voltage, it is regarded that the welding voltage has entered the short-circuit period and the short-circuit current waveform control is performed in the short-time period (S3); A step (S4) of calculating a short-circuit value up to the present by integrating a short-circuit time which is a time interval from the start of the short-circuit period to the square of the current after the step (S3); And a step (S5) of lowering the accumulated welding current value to a predetermined welding current value when the accumulated short circuit value after the step (S4) is greater than the arc reproduction predicted value.

Description

{Welding Arc Regeneration Expectation Method for Reduction Spatter}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a welding arc regeneration prediction method for reducing spatter, and more particularly, to a method for predicting the regeneration of an arc so as to improve a welding quality by reducing a spatter generated during welding .

Generally, in the arc ignition method in various welding methods (MIG, MAG, carbonic acid gas welding, etc.) using a consumable electrode, a current abruptly flows when the wire comes into contact with the base material, the wire is melted by the heat action by the current, And the arc is generated when the wire is cut.

Since this is an arc ignition method by a small explosion, a lot of spatters are generated in welding. Therefore, in the low current regions 100A to 150A, the phenomenon becomes prominent, and it is difficult to obtain a beautiful weld bead.

Also, the wire may be pressed against the welding torch tip during ignition.

Furthermore, welding in the low current region causes the volume to transition from a consumable electrode rod to a molten pool in a short-circuit transition fashion.

In the short-circuit mode, arcs and short-circuits appear periodically, and many spatters occur in the range from short-circuit to arc. This is because, when an arc occurs, the volume and the volume of the molten metal that have not been transferred to the melting furnace due to the strong explosive force and the melting point are scattered.

As described above, since the spatter generated in the region passing from the short to the arc is adhered to the base material in the molten state, the weld bead becomes poor and further processing for removing such spatter is required.

Therefore, in order to reduce the occurrence of spatter, a conventional welding machine has been used to suppress the rapid rise of the current by performing the current waveform control. However, this method delays the rise of the current during the short circuit, thereby weakening the electromagnetic force To be a normal short circuit.

In other words, there is a method of increasing the initial current rise slope and decreasing the current rise rate above the set current, thereby keeping the current at the time of arc recovery low, increasing the initial current rise slope, , These methods could not completely prevent the generation of a large amount of spatter in the process of passing from paragraph to arc.

The contents of "Mechanical Waveform Control Method and Apparatus" disclosed in Korean Patent Laid-Open No. 10-2009-112922 (hereinafter referred to as "Patent Document 1") detect the short-circuit state and arc- The arc is regenerated by advancing or reversing the wire mechanically so as to control short-circuit and arc regeneration, and the welding power supplied during welding is controlled to prevent occurrence of a momentary short circuit and to minimize the arc regeneration current. In the arc section, the feed motor is rotated forward to advance the wire. In the disclosure of the patent document 1, whether the arc section is a short-circuit section or not is determined by acquiring the welding voltage.

Therefore, it is not possible to predict the arc reproduction time that goes from the short-circuit to the arc. In other words, if the arc is generated (the occurrence is recognized as a voltage) by reversing the wire in the shorting section, it is a mechanical method of advancing the wire.

Korean Patent Publication No. 10-2009-112922 (Published on October 29, 2009)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a welding apparatus and a welding method, To be significantly reduced.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including: measuring a welding voltage while performing welding; Comparing the current welding voltage value with a predetermined short-circuit voltage value after this step; If the welding voltage after the step is less than or equal to the short-circuit voltage, considering that the welding voltage enters the short-circuiting period and performing the short-circuit current waveform control in the short-circuiting period; Calculating a short circuit value from the start of the short circuit section to the present time after the step; And decreasing the welding current value to a preset welding current value when the accumulated short circuit value after the step is greater than the arc welding predicted value.

The arc reproduction predicted value is measured by measuring a welding current during welding, determining a short-circuit interval by welding current data when welding is completed, obtaining a short-circuit value as an energy to be arc-regenerated, and multiplying the short-circuit value by a weight.
The weight is set within a range of 0.5 or more and less than 1.

As described above, the present invention has the effect of reducing the spatter that can occur during welding by predicting the arc reproduction time in advance and lowering the welding current value immediately before the arc is generated.

1 is a flowchart showing a prediction method according to the present invention.
2 is a diagram showing a short-circuit transfer mode welding current waveform.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flowchart showing an arc reproduction predicting method according to the present invention. As shown in FIG. 1, a step (S1) of measuring a welding voltage while performing welding; (S2) comparing the current welding voltage value after the step S1 with a predetermined short-circuit voltage value; If the welding voltage is less than or equal to the short-circuit voltage after the step S2, it is regarded as entering the short-circuit period, and the short-circuit current waveform control is performed in the short-circuit period (S3); A step (S4) of calculating a short-circuit value from the start of the short-circuit period to the present time after the step S3; And a step (S5) of lowering the accumulated welding current value to a preset welding current value when the accumulated short circuit value after the step S4 is greater than the arc reproduction predicted value.

The step S1 of measuring the welding voltage includes two methods of measuring the voltage at both ends of the welding output and connecting the voltage measuring signal line at the torch portion. Although the connection method is closer to the actual welding voltage, both are possible.

In addition, the voltage measured from the signal line on the welding output or torch is applied to the inside of the welding control board and measured in real time.
The predetermined short-circuit voltage value in step S1 may be generally determined as follows. In the short transition mode, the arc and the short circuit appear periodically. The arc and the short section can be obtained by acquiring the welding voltage value, the voltage value is low in the short section, the voltage value is high in the arc section, The value of the short-circuit voltage can be determined in advance by analyzing the value of the short-circuit voltage.

If the welding voltage is smaller than or equal to the short-circuit voltage, the process proceeds to the next step (S3). If the welding voltage is smaller than or equal to the short-circuit voltage, If it is large, it is not performed in the next step S3 and is fed back again.

If it is determined in the step (S3) that the short-circuit period is present, the welder control board performs the current waveform control through the pulse width modulation control.

In addition, in step S4, the integration is performed by a digital signal processor (DSP) in the welder control board from the start of the short-circuit interval, and when the short-circuit value is determined by integrating, the square of the current is multiplied by the time interval and integrated.

Fig. 2 is a diagram showing a short-circuit transition mode welding current waveform. As shown in Fig. 2, when the abscissa is time and the ordinate is the current value, the short-circuit value is integrated with the area in the dotted line.

This can be expressed by the following equation (1).

[Equation 1]
Paragraph value = ∫I ² dt

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Where I is the current.

When determining the arc reproduction predicted value, the welding wire and the welding gas to be used are determined, and the welding voltage and the welding current are measured using a conventional measuring device such as an oscilloscope while performing the welding.

In addition, lowering to the preset current value in step S5 is performed through the pulse width modulation control.

When the welding is completed, a short-circuit section is determined by the welding current and the welding voltage data, and if a certain amount of energy is applied, arc recovery is obtained. Here, the energy becomes a short-circuit value and is expressed as Equation (1).

Further, the arc reproduction predicted value is determined by multiplying the short-circuit value by a weight, and the maximum value of the weight is 1.
That is, the arc reproduction predicted value = short-circuit value x weight value.

Here, the range of the weights is between 0.5 and 1, and is selected through the experiment with the value closest to 1. If the weight is set to 1, there is no meaning as an arc reproduction predicted value since the arc has already occurred. If the weight is selected to be too small, it takes a long time for the arc to be reproduced even after the current is lowered. Therefore, the arc reproduction predicted value is selected as the weight value closest to 1, and it is confirmed through experiments that it is stable.
In other words, it is preferable to select the weight within the range of 0.5 to less than 1.

In addition, the selection of the welding data for determining the short-circuit interval is performed as follows.

The start of a paragraph is the end of a paragraph if the current welding voltage value mentioned above is smaller than the short-circuit voltage value, then the start of the short-circuit voltage, and the current welding voltage value becomes larger than the short-circuit voltage value after entering the short- .
If the short-circuiting value is larger than the short-circuiting value in step S5, the welding current value is lowered to a predetermined welding current value, so that the spatter generated during arc welding can be remarkably reduced, It can be.
In other words, to reduce the spatter, it is important to lower the current just before the arc is regenerated. For example, lowering the current before arc regeneration may delay the arc regeneration. Conversely, if the current is lowered after arc regeneration, Therefore, the arc reproduction predicted value is a value for detecting the immediately preceding arc reproduction.
The cumulative short-circuit value described in Equation (1) means that the instant when the arc reproduction predicted value is exceeded becomes the situation immediately before the arc regeneration, and that the arc is regenerated can be confirmed by looking at the welding voltage value.

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It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. It will be possible. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (3)

Measuring a welding voltage while performing welding (S1);
(S2) comparing the current welding voltage value after the step (S1) with a predetermined short-circuit voltage value;
If the welding voltage after step S2 is less than or equal to the short-circuit voltage, it is regarded that the welding voltage has entered the short-circuit period and the short-circuit current waveform control is performed in the short-time period (S3);
A step (S4) of calculating a short-circuit value up to the present by integrating a short-circuit time which is a time interval from the start of the short-circuit period to the square of the current after the step (S3);
(S5) lowering the accumulated welding current value to a preset welding current value when the short circuit value accumulated until the present time after the step (S4) becomes larger than the arc reproduction predicted value;
Wherein the welding is performed by a welding machine.
The method according to claim 1,
The arc re-
The welding current and the welding voltage are measured during the welding process. When the welding is completed, the welding current and the welding voltage data are used to determine the short-circuit interval. The short-circuit value obtained from the step S4, And multiplying the short-circuit value by a weight to acquire the short arc value.
The method of claim 2,
Wherein the weight is set within a range of 0.5 or more and less than 1.

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