JPH11309574A - Weld quality judging method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly judge the quality of a welded layer. SOLUTION: After welding work is finished, one of respective signals 8s-13s which are held in a weld signal holding means 14 is compared with a prescribed first stage threshold C1 , C2 which are held in a first stage threshold holding means 16 in a quality judging means 19 to judge the quality of a welded layer 7. Or two of respective signals 8s-13s which are held in the weld signal holding means 14 are compared with the range of a detected value determined by a second stage threshold lines P11 , P12 , P21 , P22 which are held in a second stage threshold data holding means 17 to judge the quality of the welded layer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for judging welding quality.

[0002]

2. Description of the Related Art Conventionally, when constructing a structure that is not to be mass-produced, such as a power plant or a bridge, various members such as piping members and components are manually welded to each other. In recent years, with the decrease in skilled welding workers, introduction of a fully automatic welding apparatus to the construction of the above-described structure has been studied.

FIG. 4 shows an example of a TIG welding torch used in a fully automatic welding apparatus. This TIG welding torch includes a non-consumable electrode 1 made of tungsten and a portion near the base end of the electrode 1 in a circumferential direction. And a gas nozzle 3 for discharging an inert gas 2 such as argon gas toward the front of the electrode 1. A filler wire 4 as a welding material is continuously provided in front of the tip of the electrode 1. It is being sent.

When a welding operation is performed with a TIG welding torch, the tip of the electrode 1 is made to face the member 5 to be welded, 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 welding are performed. The part of the target member 5 facing the electrode 1 is set to an inert gas atmosphere.

Then, 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 a filler wire 4 is continuously provided in front of the tip of the electrode 1. By feeding the filler wire, the tip of the filler wire 4 is melted in an inert gas atmosphere,
The welding layer 7 that melts into the welding target member 5 is formed.

[0006] When performing arc welding, 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, thereby changing the welding arc length (the length of the electrode 1). If the distance from the tip to the surface of the welding target member 5 becomes excessively large, an undercut or an overlap occurs due to poor welding at the surface portion of the welding layer 7, and an excessively small amount occurs inside the welding layer 7. Defects such as poor penetration due to melting occur.

Further, the moving speed of the TIG welding torch with respect to the welding target member 5 (welding speed), the feeding speed of the filler wire 4 with respect to the arc 6 (wire feeding speed), and the height of the TIG welding torch with respect to the welding target member 5 ( Even when the torch height) and the discharge flow rate of the inert gas 2 from the gas nozzle 3 (inert gas flow rate) deviate from appropriate ranges, disturbances in arc phenomena such as poor welding, excessive melting, and poor bead shape occur. In addition, various defects occur in the welding layer 7.

Therefore, various detecting means for detecting a welding voltage, a welding current, a welding speed, a wire feeding speed, a torch height, and an inert gas flow rate when performing a welding operation are attached to a fully automatic welding apparatus. As shown in FIG. 3, the relationship between the change in the welding signal and the disturbance of the arc phenomenon is grasped in advance using the welding signal output from each detecting means as a parameter. Determination of the quality of the welding layer 7 based on this is being studied.

That is, the detected value of the welding signal is the target value (median value) of the standard condition where the arc phenomenon is normal.
If the value deviates greatly from the appropriate range S in the vicinity, it means that the weld layer 7 has poor quality due to the disturbance of the arc phenomenon.

[0010]

However, when both of the two welding signals indicated by broken lines in FIG. 3 change simultaneously,
Second grade threshold B ₂ of the second grade threshold B ₁ and a lower limit below which can be kept good quality of the welded layer 7, when one of the welding signal shown by the solid line in FIG. 3 changes alone In addition, the upper limit first-stage threshold value C at which the quality of the weld layer 7 can be kept good.
x ₁ (Cy ₁ ) and lower limit first-stage threshold value Cx ₂ (Cy ₂ )
Between.

That is, if attention is paid only to a change in one welding signal in determining the quality of the welding layer 7, the detected value of the welding signal is equal to the two first-step thresholds Cx _1.
It changes between (Cy ₁ ) and Cx ₂ (Cy ₂ ), and even if the apparent quality of the weld layer 7 is good, the quality of the weld layer 7 is poor due to a change in another welding signal. Sometimes.

The first-step thresholds Cx ₁ , Cx ₂ , Cy ₁ and Cy ₂ of the two welding signals are changed to the second-step thresholds B ₁ and B ₁ .
When combined in B _2, for example, such as when only one of the welding signal and the other welding signals deviate from the range between the second grade threshold B _1, B ₂ is a proper range S are welded An erroneous determination that a quality defect has occurred in the layer 7 may be made.

Further, the first-stage thresholds Cx ₁ , Cx ₂ , Cx
If the settings of y ₁ and Cy ₂ are not appropriate, the quality judgment of the welded layer 7 will not be performed accurately.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to enable the quality of a weld layer to be accurately determined.

[0015]

In order to achieve the above object, a method for judging welding quality according to the present invention provides a welding voltage, a welding current, a welding speed, a wire feeding speed, a torch height, When a plurality of events in the inert gas flow rate are used as welding signals, a relationship between a change in the welding signal and disturbance of the arc phenomenon is grasped in advance for each welding signal, and one of the welding signals changes alone. Various first-stage threshold values that can maintain good quality of the weld layer are determined for each welding signal, and various detections that can maintain good quality of the weld layer when two welding signals change simultaneously. The range of values is determined for each combination of various welding signals based on the first step threshold value of both welding signals, and the welding signal is detected and recorded at the time of actual welding work, and when one welding signal changes alone, Weld signal detected and recorded The quality of the weld layer is determined by comparing various values with the first-step thresholds, and when two welding signals change simultaneously, the detected and recorded welding signal is compared with various detection value ranges. The quality of the weld layer is determined. When three or more welding signals change simultaneously, the quality of the weld layer is determined by comparing the detected and recorded welding signal with the range of various detection values for each combination of welding signals. I do.

Further, in the welding quality judging device of the present invention, each event of a welding voltage, a welding current, a welding speed, a wire feeding speed, a torch height, and an inert gas flow rate when performing a welding operation is determined by a welding signal. A plurality of detection means for detecting as
Welding signal holding means for holding a welding signal from the detection means, signal selection means for selecting a welding signal held by the welding signal holding means, and the quality of the welding layer is reduced when each welding signal changes independently. First stage threshold holding means for holding data of various first stage thresholds which can be kept well;
A second-stage threshold data holding means for holding data in various detection value ranges that can maintain good quality of the weld layer when two welding signals change simultaneously; and a first-stage threshold value holding means. Contrast value selecting means for selecting a range of the detected values held in the held first-step threshold value or second-step threshold value data holding means; a welding signal selected by the signal selecting means; Quality judgment means for judging whether or not a defect has occurred in the weld layer based on the range of the first step threshold value or the detection value selected by the means.

In the welding quality determination method according to 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, two of the welding signals are compared with the range of the detection value related to the welding signal to improve the accuracy of the quality determination of the welding layer.

Further, in the welding quality judging device of the present invention, after the welding operation is completed, one of the welding signals held in the welding signal holding means and one of the welding signals held in the first stage threshold value holding means are held. The predetermined threshold value is compared with the quality determination means to determine the quality of the weld layer, or,
By comparing two of the welding signals held in the welding signal holding means with a predetermined detection value range held in the second stage threshold data holding means, the accuracy of the quality determination of the weld layer is improved. Plan.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of an embodiment of a welding quality judgment apparatus according to the present invention. In the drawing, the parts denoted by the same reference numerals as those in FIG. 4 represent the same parts.

This welding quality judging device comprises a voltage detecting means 8, a current detecting means 9, a welding speed detecting means 10, a wire feeding speed detecting means 11, a torch height detecting means 12, a gas flow detecting means 13, a welding signal holding means. A means 14, a signal selecting means 15, a first-step threshold value holding means 16, a second-step threshold data holding means 17, a contrast value selecting means 18, a quality judging means 19, and a display 20 are provided.

The voltage detecting means 8 detects a 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. ing.

The current detecting means 9 detects a welding current A supplied to the electrode 1 of the welding torch 22 by the welding power source 21 and outputs a welding current signal 9s.

The welding speed detecting means 10 includes a welding torch 22
, Ie, the welding speed M, and outputs a welding speed signal 10s.

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.

The torch height detecting means 12 includes the welding torch 2
2 is connected to the laser-type sensor head 23 mounted on the sensor 2 and detects the torch height L with respect to the welding target member 5;
The torch height signal 12s is output.

The gas flow detecting means 13 is connected to a welding torch 22 by a flow regulating valve 25 attached to the inert gas filled container 24.
It is configured to detect a flow rate G of the inert gas fed to the apparatus and output a gas flow rate signal 13s.

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.

The signal selection means 15 outputs a selection signal 15s to the welding signal holding means 14 by manual operation, and outputs one signal X or two signals among the signals 8s to 13s held by the welding signal holding means 14. It is configured to select X and Y.

The first-stage threshold value holding means 16 stores various first-order threshold values which can maintain good quality of the welded layer 7 when one of the signals Xs to 13s changes alone.
Grade threshold C _1, C ₂ is held for each signal 8s~13s as a single change data.

The second stage threshold data holding means 17 can keep the quality of the weld layer 7 in a good state when two signals X and Y of the signals 8s to 13s change simultaneously. Various detection value ranges Q are held as correlation change data for all combinations of the signals 8s to 13s.

This range Q is, as shown in FIG.
A flat with the aim values Ax and Ay under the standard conditions of X and Y as the origin
The first-step threshold value Cx of the signal X in the plane coordinates₁When
First-stage threshold value Cy of signal Y₁The second stage between
Price line P₁₁, The first step threshold Cx of the signal X₁And signal Y
First-stage threshold Cy_TwoSecond threshold line connecting
P ₁₂, The first step threshold Cx of the signal X_TwoAnd the first of signal Y
Step threshold Cy₁-Level threshold line P connecting_{twenty one},
And the first-stage threshold value Cx of the signal X_TwoAnd the first stage of signal Y
Floor threshold Cy_Two-Level threshold line P connecting_{twenty two}Surrounded by
The target values Ax, Ay, and
Conventional second stage threshold B₁, B_Two(See Fig. 3)
Second stage threshold Bx₁, Bx_Two, By₁, By_TwoYes
The shift is also caused by the second-stage threshold line P₁₁, P₁₂, P_{twenty one}, P_{twenty two}so
It is included in the enclosed area.

That is, in the correlation change data, the signals X,
The second-stage threshold value of Y is changed to the second-stage threshold line P _11
12, is regarded as a variable on the P _21, P _22.

The range Q of the detected value is set for each of the various first-stage thresholds C ₁ and C ₂ held in the first-stage threshold holding means 16, and the various first-stage thresholds C ₁ and C ₂ are set. According to the step thresholds C ₁ and C ₂ , the second step threshold lines P ₁₁ , P ₁₂ ,
First stage thresholds Cx ₁ , Cx ₂ , C determining P ₂₁ , P ₂₂
As y ₁ and Cy ₂ fluctuate, the range of the detection value range Q is enlarged or reduced.

The contrast value selecting means 18 is manually operated.
A selection signal 18s is output to the first-stage threshold value holding means 16 and the second-stage threshold value data holding means 17, and the predetermined threshold values C ₁ , C ₂ , or the second-stage threshold line P ₁₁ ,
It is configured to select P ₁₂ , P ₂₁ , and P ₂₂ (range Q of detected values).

The quality judging means 19 selects one signal X or two signals X and Y selected by the signal selecting means 15.
And the first-step thresholds C ₁ and C ₂ selected by the contrast value selection means 18 or the second-step threshold lines P ₁₁ and P ₁₁ ,
Based on P ₁₂ , P ₂₁ , and P ₂₂ , it is configured to determine whether a defect has occurred in the welding layer 7 and output a determination signal 19 s.

The display 20 is configured to display the presence or absence of a defect in the welding layer 7 in accordance with a judgment signal 19s from the quality judgment means 19.

When welding the member 5 to be welded using the welding torch 22, the welding voltage V, welding current A, welding speed M, wire feeding speed N, torch height L, and inert gas flow rate G are determined. Each is detected by the detecting means 8 to 13,
The signals 8 s to 13 s from the detection means 8 to 13 are held in the welding signal holding means 14.

When the quality of the welding layer 7 is determined after the welding operation is completed, for example, when the quality of the welding layer 7 is determined by focusing on the change in the welding voltage V, the welding voltage signal 8s is selected. The selection signal 15s to be transmitted to the signal selection unit 1
5 to the welding signal holding means 14, and outputs the welding voltage signal 8
A selection signal 18 s for selecting a predetermined first step threshold value C ₁ or C ₂ for s is output from the contrast value selection means 18 to the first step threshold value holding means 16.

Thus, the quality judging means 19 compares the welding voltage signal 8s with the predetermined first-step thresholds C ₁ and C ₂ to judge whether or not the weld layer 7 has a defect.

Further, the judgment signal 1 from the quality judgment means 19
In response to 9 s, the display 20 displays the quality determination result of the welding layer 7.

If another first step threshold C ₁ , C ₂ is selected by the comparison value selecting means 18, the welding voltage signal 8 s and the other first step threshold C ₁ , C ₂ become different. Will be contrasted.

Further, by changing the selection target by the signal selection means 15 and the comparison value selection means 18, it is possible to determine the quality of the weld layer 7 focusing on other events such as the welding current A other than the welding voltage V. .

In determining the quality of the weld layer 7,
For example, when the quality of the welding layer 7 is determined by paying attention to changes in the welding voltage V and the welding current A, a selection signal 15 s for selecting the welding voltage signal 8 s and the welding current signal 9 s is transmitted from the signal selection unit 15 to the welding signal 15 s. A selection signal 1 that is output to the signal holding means 14 and selects the second-step threshold lines P ₁₁ , P ₁₂ , P ₂₁ , and P ₂₂ for the welding voltage signal 8s and the welding current signal 9s.
8s is output from the contrast value selecting means 18 to the second stage threshold data holding means 17.

Accordingly, the quality judging means 19 compares the welding voltage signal 8s and the welding current signal 9s with the range Q of the detection value determined by the second-step threshold lines P ₁₁ , P ₁₂ , P ₂₁ , P _22. Then, it is determined whether or not the welding layer 7 has a defect.

Further, the judgment signal 1 from the quality judgment means 19
In response to 9 s, the display 20 displays the quality determination result of the welding layer 7.

Further, another value is selected by the contrast value selecting means 18.
Second stage threshold line P₁₁, P₁₂, P _{twenty one}, P_{twenty two}Determined by
Is selected, the welding voltage signal 8s and the
The welding current signal 9s is compared with another detection value range Q.
Will be.

Further, if the object of selection is changed to the selection by the signal selection means 15 and the comparison value selection means 18, the welding layer 7 focusing on two combinations other than the combination of the welding voltage V and the welding current A can be obtained. Can be determined.

As described above, in the welding quality judging device shown in FIG. 1, after the welding operation is completed, the welding signal holding means 14
Is compared with one of the signals 8s to 13s held in the first step threshold value holding means 16 and the predetermined first step threshold values C ₁ and C ₂ in the quality judgment means 19. To determine the quality of the welding layer 7 or, of the signals 8s to 13s held in the welding signal holding means 14,
Since the quality of the welding layer 7 is determined by comparing the predetermined detection value range Q held in the second-stage threshold data holding means 17 with the quality of the welding layer 7, the quality of the welding layer 7 is improved. The judgment can be made accurately.

The method and apparatus for judging welding quality according to the present invention are not limited to the above-described embodiment.
It goes without saying that the present invention can be applied to arc welding other than TIG welding such as MAG welding, and that other changes can be made without departing from the scope of the present invention.

[0051]

As described above, the method and apparatus for judging welding quality according to the present invention can provide various excellent effects as described below.

(1) In the welding quality judgment method of the present invention, after the welding operation is completed, one of the welding signals is compared with a predetermined threshold value related to the welding signal to determine the quality of the welding layer. Or the quality of the weld layer is determined by comparing two of the welding signals with the range of the detection value related to the weld signal. Can be.

(2) In the welding quality judging device of the present invention, after the welding operation is completed, one of the welding signals held in the welding signal holding means and one of the welding signals held in the first step threshold holding means are held. The quality of the welding layer is determined by comparing the predetermined threshold value with the quality determination means, or two of the welding signals held in the welding signal holding means and a second-step threshold value are determined. Since the quality of the weld layer is determined by comparing with a predetermined range of the detection value held in the data holding means, the quality determination of the weld layer can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of an embodiment of a welding quality determination device of the present invention.

FIG. 2 is a graph showing a second-stage threshold line held as data in a second-stage threshold data holding unit.

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]

Reference Signs List 7 welding layer 8 voltage detecting means 8s welding voltage signal (welding signal) 9 current detecting means 9s welding current signal (welding signal) 10 welding speed detecting means 10s welding speed signal (welding signal) 11 wire feeding speed detecting means 11s wire feeding Feed speed signal (welding signal) 12 Torch height detecting means 12s Torch height signal (welding signal) 13 Gas flow rate detecting means 13s Gas flow rate signal (welding signal) 14 Welding signal holding means 15 Signal selecting means 16 First stage threshold value holding unit 17 second grade threshold data holding means 18 comparison value selecting means 19 quality judging unit A welding current _{C 1, C 2, Cx 1} , Cx 2, Cy 1, Cy 2 first grade threshold G not Active gas flow rate L Torch height M Welding speed N Wire feeding speed Q Range of detected value V Welding voltage X, Y signal (welding signal)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Tagami 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Ishikawashima Harima Heavy Industries, Ltd. No. 1 Ishi Kawashima Harima Heavy Industries, Ltd. Yokohama Engineering Center

Claims (2)

[Claims] 1. A change in a welding signal when a plurality of events among a welding voltage, a welding current, a welding speed, a wire feeding speed, a torch height, and an inert gas flow rate during a welding operation are used as a welding signal. The relationship between the welding and the disturbance of the arc phenomenon is grasped in advance for each welding signal, and various first-stage threshold values that can maintain good quality of the welding layer when one of the welding signals changes alone are set. For each welding signal, the range of various detection values at which the quality of the weld layer can be kept good when the two welding signals change simultaneously is determined based on the first step threshold values of both welding signals. Determined for each signal combination,
The welding signal is detected and recorded during the actual welding operation, and when one welding signal changes alone, the quality of the weld layer is determined by comparing the detected and recorded welding signal with the first-step thresholds of various values. When the two welding signals change simultaneously, the quality of the weld layer is determined by comparing the detected and recorded welding signal with the range of various detection values, and when three or more welding signals change simultaneously, the detection is performed. A welding quality determination method characterized by comparing a recorded welding signal and a range of various detection values for each combination of welding signals to determine the quality of a welding layer. 2. A plurality of detecting means for detecting each event of a welding voltage, a welding current, a welding speed, a wire feeding speed, a torch height, and an inert gas flow rate when performing a welding operation as a welding signal; Welding signal holding means for holding a welding signal from the detection means, signal selection means for selecting a welding signal held by the welding signal holding means, and the quality of the welding layer is reduced when each welding signal changes independently. First-stage threshold value holding means for holding data of various first-stage threshold values that can be kept well, and various kinds of devices that can keep good quality of the weld layer when two welding signals change simultaneously. Second-stage threshold data holding means for holding data in the range of the detection value, and holding in the first-step threshold value or second-step threshold data holding means held in the first-step threshold value holding means The range of detected values Whether the weld layer has a defect based on the selected comparison value selection means, the welding signal selected by the signal selection means, and the range of the first step threshold value or the detection value selected by the comparison value selection means. A welding quality judging device comprising: a quality judging means for judging.