JP3906561B2 - Welding quality judgment method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding quality determination method and apparatus.
[0002]
[Prior art]
Conventionally, when constructing structures that are not subject to mass production, such as power plant equipment or bridges, various members such as piping members and structural members are welded to each other manually, but in recent years, skilled welding has been performed. As the number of workers decreases, it has been studied to introduce a fully automatic welding apparatus to construct the structure.
[0003]
FIG. 4 shows an example of a TIG welding torch used in a fully automatic welding apparatus. The TIG welding torch surrounds a non-consumable electrode 1 formed of tungsten and a portion near the proximal end of the electrode 1 in the circumferential direction. A gas nozzle 3 for letting out an inert gas 2 such as argon gas flows out toward the front of the electrode 1. A filler wire 4 as a welding material is continuously fed to the front end of the electrode 1. It has become so.
[0004]
When performing the welding operation with the TIG welding torch, the tip of the electrode 1 is opposed to the member to be welded 5 and the inert gas 2 is caused to flow out from the gas nozzle 3 so that the portion near the tip of the electrode 1 and the member to be welded 5 The part facing the electrode 1 is made an inert gas atmosphere.
[0005]
Next, a voltage is applied to the electrode 1 and the welding target member 5 to generate an arc 6 between the tip of the electrode 1 and the welding target member 5, and the filler wire 4 is continuously fed forward of the tip of the electrode 1. By supplying, the front-end | tip of this filler wire 4 is fuse | melted in inert gas atmosphere, and the welding layer 7 melt | dissolved in the member 5 to be welded is formed.
[0006]
When arc welding is performed, for example, a welding voltage applied between the electrode 1 and the welding target member 5 or a welding current applied to the electrode 1 changes, so that the welding arc length (welding from the tip of the electrode 1 is welded). If the distance to the surface of the target member 5 is excessive, undercut or overlap due to poor welding occurs on the surface portion of the weld layer 7, and due to undermelting in the weld layer 7. Defects such as poor penetration occur.
[0007]
Moreover, the moving speed (welding speed) of the TIG welding torch with respect to the welding target member 5, the feeding speed (wire feeding speed) of the filler wire 4 with respect to the arc 6, and the height of the TIG welding torch with respect to the welding target member 5 (torch height) ), And when the discharge flow rate (inert gas flow rate) of the inert gas 2 from the gas nozzle 3 deviates from the appropriate range, the arc phenomenon such as poor welding, excessive melting, and poor bead shape occurs, resulting in a welded layer. 7 has various defects.
[0008]
Therefore, various detection means for detecting the welding voltage, welding current, welding speed, wire feeding speed, torch height, and inert gas flow rate when performing the welding work are attached to the fully automatic welding apparatus, and each detection means As shown in FIG. 3, the relationship between the change of the welding signal and the disturbance of the arc phenomenon is grasped in advance and the welding signal output from the welding signal is detected based on the welding signal detected during the actual welding operation. Determining the quality of layer 7 is being considered.
[0009]
That is, if the detected value of the welding signal deviates significantly from the appropriate range S near the target value (median value) of the standard condition in which the arc phenomenon is normal, the quality defect caused by the disturbance of the arc phenomenon is welded. It has occurred in layer 7.
[0010]
[Problems to be solved by the invention]
However, when both of the two welding signals indicated by the broken lines in FIG. 3 change simultaneously, the upper limit second stage threshold value B ₁ and the lower limit second stage threshold at which the quality of the weld layer 7 can be maintained well. The value B ₂ is the upper limit first-stage threshold value Cx ₁ (Cy ₁ ) and the lower limit at which the quality of the weld layer 7 can be maintained satisfactorily when one welding signal indicated by a solid line in FIG. 3 changes alone. Between the first-stage threshold value Cx ₂ (Cy ₂ ).
[0011]
That is, when determining the quality of the weld layer 7, if only attention is paid to a change in one welding signal, the detected value of the welding signal is expressed by both first-stage threshold values Cx ₁ (Cy ₁ ), Cx ₂ ( cy ₂₎ varies between, there may be a good quality of the welded layer 7 apparent, the welding layer 7 by a change in other welding signal quality defect has occurred.
[0012]
If the first stage threshold values Cx ₁ , Cx ₂ , Cy ₁ , and Cy ₂ of the two welding signals are matched with the second stage threshold values B ₁ and B ₂ , for example, only one welding signal is the first stage signal. When the value deviates from the range between the two-stage threshold values B ₁ and B ₂ and the other welding signal is within the appropriate range S, it is erroneously determined that a quality defect has occurred in the weld layer 7. There is.
[0013]
Furthermore, when the setting of the first stage threshold values Cx ₁ , Cx ₂ , Cy ₁ , Cy ₂ is not appropriate, the quality determination of the weld layer 7 is not performed accurately.
[0014]
The present invention has been made in view of the above-described circumstances, and an object thereof is to make it possible to accurately determine the quality of a weld layer.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, in the welding quality judgment method of the present invention, a plurality of welding voltages, welding currents, welding speeds, wire feed speeds, torch heights, and inert gas flow rates when performing a welding operation are used. Using the event as a welding signal, the relationship between the change in the welding signal and the disturbance of the arc phenomenon is grasped in advance for each welding signal, and when one of the welding signals changes independently, the quality of the welded layer is kept good. Different first stage thresholds can be defined for each welding signal, and the range of different detection values that can maintain good weld layer quality when the two welding signals are changed simultaneously. It is determined for each combination of various welding signals based on the first stage threshold, and the welding signal is detected and recorded during actual welding work. When one welding signal changes independently, the detected welding signal and various values are recorded. First stage threshold of The quality of the weld layer is judged by comparing the two welding signals, and when the two welding signals change simultaneously, the quality of the weld layer is judged by comparing the detected and recorded welding signal with various detection value ranges. When the welding signals are simultaneously changed, the quality of the welded layer is determined by comparing the detected and recorded welding signals with various detection value ranges for each combination of welding signals.
[0016]
In the welding quality judgment device of the present invention, the welding voltage, welding current, welding speed, wire feed speed, torch height, and inert gas flow rate during welding work are detected as welding signals. A plurality of detection means, a welding signal holding means for holding a welding signal from the detection means, a signal selection means for selecting a welding signal held in the welding signal holding means, and when each welding signal changes independently First-stage threshold value holding means for holding various first-stage threshold value data that can maintain good weld layer quality, and good weld layer quality when two welding signals change simultaneously A second-stage threshold value data holding means for holding data in a range of various detection values that can be maintained at a first-stage threshold value or a second-stage threshold value held in the first-stage threshold value holding means. Stored in the value data storage means A comparison value selection means for selecting a range of detected values, a welding signal selected by the signal selection means, and a first stage threshold value or a range of detection values selected by the contrast value selection means. Quality judging means for judging whether or not a defect has occurred.
[0017]
In the welding quality determination method of the present invention, after the welding operation is completed, the quality of the weld layer is determined by comparing one of the welding signals with a predetermined threshold value related to the welding signal, or The accuracy of the quality determination of the weld layer is improved by comparing two of the welding signals with a range of detection values related to the welding signal.
[0018]
In the welding quality judgment device of the present invention, after the welding operation is completed, one of the welding signals held by the welding signal holding unit and a predetermined level held by the first stage threshold holding unit. The quality judgment means compares the threshold value to judge the quality of the weld layer, or two of the welding signals held in the welding signal holding means and the second stage threshold data holding means hold it. The accuracy of the quality judgment of the weld layer is improved by comparing with the predetermined detection value range.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
1 and 2 show an example of an embodiment of a welding quality determination device according to the present invention. In the figure, the same reference numerals as those in FIG. 4 denote the same components.
[0021]
This welding quality judgment device includes a voltage detection means 8, a current detection means 9, a welding speed detection means 10, a wire feed speed detection means 11, a torch height detection means 12, a gas flow rate detection means 13, a welding signal holding means 14, A signal selection means 15, a first stage threshold value holding means 16, a second stage threshold value data holding means 17, a contrast value selection means 18, a quality judgment means 19, and a display 20 are provided.
[0022]
The voltage detection means 8 detects the welding voltage V applied between the electrode 1 of the welding torch 22 and the member 5 to be welded by the welding power source 21, and outputs a welding voltage signal 8s.
[0023]
The current detection means 9 detects a welding current A energized to the electrode 1 of the welding torch 22 by the welding power source 21 and outputs a welding current signal 9s.
[0024]
The welding speed detection means 10 detects the moving speed of the welding torch 22, that is, the welding speed M, and outputs a welding speed signal 10s.
[0025]
The wire feed speed detecting means 11 detects the wire feed speed N of the filler wire 4 and outputs a wire feed speed signal 11s.
[0026]
The torch height detecting means 12 is connected to a laser-type sensor head 23 attached to the welding torch 22, detects the torch height L with respect to the welding target member 5, and outputs a torch height signal 12s. ing.
[0027]
The gas flow rate detection means 13 is configured to detect an inert gas flow rate G fed from the flow rate adjustment valve 25 attached to the inert gas filling container 24 to the welding torch 22 and output a gas flow rate signal 13s. ing.
[0028]
The welding signal holding means 14 is configured to hold the position data of the welding torch 22 based on the signals 8s to 13s from the detection means 8 to 13 and the welding speed signal 10s described above.
[0029]
The signal selection unit 15 outputs a selection signal 15s for the welding signal holding unit 14 by manual operation, and one signal X of the signals 8s to 13s held by the welding signal holding unit 14 or two signals X and Y. Is configured to select.
[0030]
The first-stage threshold value holding means 16 includes various first-stage threshold values at which the quality of the weld layer 7 can be kept good when one signal X of the signals 8s to 13s changes independently. Values C ₁ and C ₂ are held for each signal 8s to 13s as single change data.
[0031]
The second-stage threshold value data holding means 17 has various detections that can maintain the quality of the welded layer 7 in a good state when two signals X and Y of the signals 8s to 13s change simultaneously. A value range Q is held for all combinations of the signals 8s to 13s as correlation change data.
[0032]
As shown in FIG. 2, the range Q is the first-stage threshold value Cx ₁ of the signal X and the first value of the signal Y within the plane coordinates with the target values Ax and Ay of the standard conditions of the signals X and Y as the origin. A second stage threshold line P ₁₁ connecting the first stage threshold value Cy ₁ and a second stage connecting the first stage threshold value Cx ₁ of the signal X and the first stage threshold value Cy ₂ of the signal Y. The threshold line P ₁₂ , the second stage threshold line P ₂₁ connecting the first stage threshold Cx ₂ of the signal X and the first stage threshold Cy ₁ of the signal Y, and the first stage of the signal X This is a detection value region surrounded by a second-stage threshold line P ₂₂ that connects the threshold value Cx ₂ and the first-stage threshold value Cy ₂ of the signal Y. The target values Ax, Ay, and the conventional second-stage value The second stage threshold values Bx ₁ , Bx ₂ , By ₁ and By ₂ corresponding to the threshold values B ₁ and B ₂ (see FIG. 3) are all the second stage threshold line P. ₁₁ , P ₁₂ , P ₂₁ , and P ₂₂ .
[0033]
That is, in the correlation change data, the second stage threshold values of the signals X and Y are regarded as variables on the second stage threshold lines P ₁₁ , P ₁₂ , P ₂₁ , and P ₂₂ .
[0034]
The detection value range Q is set for each of the various first-stage threshold values C ₁ and C ₂ held in the first-stage threshold value holding means 16, and various first-stage threshold values are set. The first stage threshold values Cx ₁ , Cx ₂ , Cy ₁ , and Cy ₂ that define the second stage threshold lines P ₁₁ , P ₁₂ , P ₂₁ , and P ₂₂ vary according to the values C ₁ and C _2. As a result, the region of the detection value range Q is enlarged or reduced.
[0035]
The contrast value selection means 18 outputs a selection signal 18 s to the first stage threshold value holding means 16 and the second stage threshold value data holding means 17 by manual operation, and holds it in the first stage threshold value holding means 16. Predetermined threshold values C ₁ and C ₂ , or second-stage threshold lines P ₁₁ , P ₁₂ , P ₂₁ and P ₂₂ (which are held in the second-stage threshold data holding means 17 ( The detection value range Q) is selected.
[0036]
The quality judgment means 19 is a signal X selected by the signal selection means 15 or two signals X and Y, and the first stage thresholds C ₁ and C ₂ selected by the contrast value selection means 18, or Based on the two-stage threshold lines P ₁₁ , P ₁₂ , P ₂₁ , and P ₂₂ , it is determined whether or not a defect has occurred in the weld layer 7 and outputs a determination signal 19 s.
[0037]
The indicator 20 is configured to display the presence / absence of a defect in the weld layer 7 in accordance with the determination signal 19 s from the quality determination means 19.
[0038]
When welding the member 5 to be welded using the welding torch 22, the welding voltage V, the welding current A, the welding speed M, the wire feed speed N, the torch height L, and the inert gas flow rate G are respectively Detection is performed by the detection means 8 to 13, and the signals 8 s to 13 s from the detection means 8 to 13 are held in the welding signal holding means 14.
[0039]
When determining the quality of the weld layer 7 after the welding operation is completed, for example, when determining the quality of the weld layer 7 by paying attention to the change of the welding voltage V, a selection signal for selecting the welding voltage signal 8s. 15 s is output from the signal selection means 15 to the welding signal holding means 14, and a selection signal 18 s for selecting predetermined first stage threshold values C ₁ and C ₂ for the welding voltage signal 8 s is output from the contrast value selection means 18. Output to the one-stage threshold value holding means 16.
[0040]
Thereby, the quality determination means 19 compares the welding voltage signal 8s with the predetermined first stage threshold values C ₁ and C ₂ to determine whether or not the weld layer 7 has a defect.
[0041]
Furthermore, the display device 20 displays the quality judgment result of the weld layer 7 in accordance with the judgment signal 19 s from the quality judgment means 19.
[0042]
Further, if another first stage threshold value C ₁ , C ₂ is selected by the contrast value selection means 18, the welding voltage signal 8 s is compared with another first stage threshold value C ₁ , C _2. It will be.
[0043]
Furthermore, if the selection object by the signal selection means 15 and the contrast value selection means 18 is changed, the quality determination of the weld layer 7 focusing on other events such as the welding current A other than the welding voltage V can be performed.
[0044]
In determining the quality of the weld layer 7, for example, when the quality determination of the weld layer 7 is performed by paying attention to changes in the welding voltage V and the welding current A, the welding voltage signal 8s and the welding current signal 9s are selected. the selection signal 15s, and the output from the signal selection means 15 to the welding signal holding means 14, selects the welding voltage signal 8s and welding current signal second grade threshold line for _{9s P 11, P 12, P} 21, P 22 The selection signal 18 s is output from the contrast value selection unit 18 to the second stage threshold value data holding unit 17.
[0045]
Thus, the quality judgment unit 19, and comparing the area Q of the detection value determined by the welding voltage signal 8s and welding current signal 9s and the second grade threshold line _{P 11, P 12, P 21} , P 22, welded It is determined whether or not the layer 7 has a defect.
[0046]
Furthermore, the display device 20 displays the quality judgment result of the weld layer 7 in accordance with the judgment signal 19 s from the quality judgment means 19.
[0047]
If the detection value range Q determined by the different second stage threshold lines P ₁₁ , P ₁₂ , P ₂₁ , P _{22 is} selected by the contrast value selection means 18, the welding voltage signal 8 s and the welding current signal 9 s are selected. Is compared with another detection value range Q.
[0048]
Furthermore, if the object is changed to the selection by the signal selection means 15 and the contrast value selection means 18, the quality determination of the weld layer 7 focusing on two combinations of events other than the combination of the welding voltage V and the welding current A. It can be performed.
[0049]
Thus, in the welding quality determination apparatus shown in FIG. 1, after the welding operation is completed, one of the signals 8 s to 13 s held in the welding signal holding unit 14 and the first stage threshold holding unit 16 are set. The predetermined first stage threshold values C ₁ and C _{2 held} are compared in the quality determination means 19 to determine the quality of the weld layer 7 or each signal held in the welding signal holding means 14 Since the quality of the weld layer 7 is determined by comparing two of 8s to 13s with the predetermined detection value range Q held in the second-stage threshold value data holding means 17, the determination accuracy is improved. Thus, the quality determination of the weld layer 7 can be performed accurately.
[0050]
In addition, the welding quality determination method and apparatus of the present invention are not limited to the above-described embodiments, but are applied to arc welding other than TIG welding including MAG welding, and others. Of course, changes can be made without departing from the scope of the invention.
[0051]
【The invention's effect】
As described above, the welding quality determination method and apparatus of the present invention can exhibit various excellent effects as described below.
[0052]
(1) In the welding quality determination method of the present invention, after the welding operation is completed, the quality of the weld layer is determined by comparing one of the welding signals with a predetermined threshold value related to the welding signal. Alternatively, since the quality of the weld layer is determined by comparing two of the welding signals with the range of detection values related to the weld signal, the quality of the weld layer can be determined accurately.
[0053]
(2) In the welding quality judgment device of the present invention, after the welding operation is completed, one of the welding signals held in the welding signal holding means and a predetermined value held in the first stage threshold holding means. The quality judgment means compares the threshold value with the quality judgment means, or two of the welding signals held in the welding signal holding means and the second stage threshold data holding means. Since the quality of the welded layer is determined in comparison with the range of the predetermined detection value held in, the quality of the welded layer can be determined accurately.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an example of an embodiment of a welding quality judgment device of the present invention.
FIG. 2 is a graph showing second-stage threshold lines held as data in second-stage threshold data holding means.
FIG. 3 is a graph showing a relationship between a change in a welding signal and disturbance of an arc phenomenon.
FIG. 4 is a conceptual diagram showing an example of a TIG welding torch.
[Explanation of symbols]
7 Welding layer 8 Voltage detection means 8s Welding voltage signal (welding signal)
9 Current detection means 9s Welding current signal (welding signal)
10 Welding speed detection means 10s Welding speed signal (welding signal)
11 Wire feed speed detecting means 11s Wire feed speed signal (welding signal)
12 Torch height detection means 12s Torch height signal (welding signal)
13 Gas flow rate detection means 13s Gas flow rate signal (welding signal)
14 welding signal holding means 15 signal selection means 16 first stage threshold value holding means 17 second stage threshold value data holding means 18 contrast value selection means 19 quality judgment means A welding currents C ₁ , C ₂ , Cx ₁ , Cx ₂ , Cy ₁ , Cy ₂ First stage threshold G Inert gas flow rate L Torch height M Welding speed N Wire feed speed Q Range of detected value V Welding voltage X, Y signal (welding signal)

Claims (2)

Changes in welding signal and turbulence of arc phenomenon with multiple events among welding voltage, welding current, welding speed, wire feed speed, torch height, and inert gas flow rate during welding work For each welding signal, and for each welding signal, various first-stage threshold values that can maintain good weld layer quality when one of the welding signals changes independently. The range of detection values that can maintain good weld layer quality when two welding signals change simultaneously is determined for each combination of various welding signals based on the first stage threshold of both welding signals. The welding signal is detected and recorded during the actual welding operation. When one welding signal changes independently, the welding signal quality is compared by comparing the detected recording signal with the first stage threshold value of various values. The two welding signals are simultaneously When there is a change, the quality of the weld layer is judged by comparing the detected and recorded welding signal with various detection value ranges. When three or more welding signals change simultaneously, the detected and recorded welding signal and various detection values are detected. A welding quality determination method, wherein the quality of a weld layer is determined by comparing a range of values for each combination of welding signals. A plurality of detection means for detecting each event of welding voltage, welding current, welding speed, wire feeding speed, torch height, and inert gas flow rate when performing a welding operation as a welding signal; The welding signal holding means for holding the welding signal, the signal selecting means for selecting the welding signal held by the welding signal holding means, and the quality of the welded layer can be kept good when each welding signal changes independently. First stage threshold value holding means for holding data of various first stage threshold values, and various detection value ranges in which the quality of the weld layer can be maintained well when two welding signals change simultaneously. A second-stage threshold data holding means for holding data, and a first-stage threshold value held in the first-stage threshold value holding means or a detection value held in the second-stage threshold value data holding means. Contrast value to select range Quality determination that determines whether or not a defect has occurred in the weld layer based on the selection means, the welding signal selected by the signal selection means, and the first-stage threshold value or detection value range selected by the contrast value selection means Means for determining a welding quality.

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