JPH0379105B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a consumable electrode type arc welding method, and particularly to a method for controlling groove profile and bead height. (Conventional technology) There has been a strong desire to automate and save labor in the welding process in order to reduce costs and stabilize quality.
Various types of automatic welding machines have been developed and are in use. However, even with automatic welding machines, the current situation is that humans must judge and operate the welding conditions.
Judgments and operations performed by humans mainly include copying changes in the weld line and controlling weld bead height in response to groove width changes. This variation in the weld line and groove width can be classified into the following two types. One is the weld line and groove width due to the preset welding torch trajectory and groove width and the actual assembly error of the welded product. One is the variation in the groove width, and the other is the variation in the weld line and groove width caused by the deformation of the steel plate due to the heat of welding. To automatically control welding, these fluctuations must first be detected accurately. Currently, many detection methods have been proposed, but they can be broadly classified into two. For example, as shown in "Current Status of Arc Welding Sensors" (Welding Technology August 1983 issue, p. 28), one method is to detect and store the groove line position and groove width using a detector before welding. , is a method of calculating and controlling the welding torch trajectory and groove width from the stored information during welding.The other method is, for example, "Current status of arc welding sensors" (Welding Technology August 1983 issue 27-28)
A method of sequentially calculating and controlling the torch trajectory and groove width while detecting the groove line and groove width using a detector placed at or in front of the arc generation point during welding, as shown in page). It is. When these two are compared, the former cannot cope with fluctuations in the groove line and groove width that occur due to deformation of the steel plate due to heat generated during welding. Since the latter detection method detects the vicinity of the arc generation point, it is considered possible to successively respond to changes in the weld line and groove width that occur due to the deformation of the steel plate due to heat. However, the latter detection method requires the detector to be installed near the welding torch, but it is extremely difficult to install the detector near the welding torch due to adverse conditions such as high heat, fumes, spatter, and light that are typical of arc welding. be. A method using the welding arc phenomenon has been proposed as an effective method to solve such problems. A control method using this type of welding phenomenon is, for example, as shown in Japanese Patent Application Laid-Open No. 106049/1984, by comparing the welding currents at the left and right ends of the weaving amplitude, and if the left end or right end is large, the welding amplitude is This method moves the center to the right or left and performs tracing control. However, the welding current with respect to the weaving amplitude has a particularly large change at both ends of the weaving amplitude. That is, FIG. 2 is a diagram showing the change in welding current with respect to the weaving amplitude, where 1 is the root width r=
A 10 mm grooved steel plate, 8 a welding torch, and 7 a welding wire.As seen in the same figure, it can be seen from the shapes of S _L and S _R that the welding current changes greatly at both ends of the weaving amplitude. . Therefore, the welding current value fluctuates greatly due to a slight error in sampling the welding current value, so the conventional control method of comparing the welding current values at both ends of the weaving has many malfunctions, making stable welding difficult. (Problems to be Solved by the Invention) The present invention solves the instability of control due to data dispersion, which was a problem with the control method using the welding arc phenomenon, and achieves a constant weld bead height with small tracing errors. The purpose is to provide a welding control method. (Means for solving the problem) The present invention focuses on such a problem and is a completely new welding control method that solves the problem. In the consumable electrode arc welding method, the welding current integrated value I _L1 in the process of moving the welding torch from the center to the left end during the weaving amplitude period is
Integrated value of welding current in the process of moving from the center to the right end
When I _R1 is the integrated value of welding current in the process of moving the welding torch from the left end to the center I _L2 , and the integrated value of welding current in the process of moving from the edge of the stone to the center I _R2 , the difference between I _L1 and I _L2 is S _L (=I _L1 −I _L2 ), and I _R1 for I _R2
The difference between S _{L and S R is} S _A (=I _R1 − I _R2 ) _.
(= S _L − S _R ), or welding according to the _sum of S _L and S _R (= S _L + S _R ). How to control the bead height so that it is constant, the position of the left end of weaving is P _Lp , the position 3 mm inside from the left end is P _Ln , and P _Lp and P _Ln within the range from P _Lp to P _Ln .
The position of any one or more points that is not equal to
P _L or P _L1 , P _L2 ,..., P _Lo (n is an integer greater than or equal to 2)
Similarly, the point on the right side of the weaving amplitude that is equal to the distance from the center of the weaving amplitude to P _L or P _L1 , P _L2 , ..., P _Lo is P _R or P _R1 , P _R2 ,
..., P _Ro , and in the process of the welding torch moving from the center to the left end during the weaving amplitude period, P _L or P _L1 ,
The welding current value at P _L2 ,..., P _Lo is i _LF or i _LF1 ,
i _LF2 ,…, i _LFo , the welding current value at P _L or P _L1 , P _L2 ,…, P _Lo in the process of the welding torch moving from the left end to the center is i _LS or i _LS1 , i _LS2 ,…, i _LSo , in the process of the welding torch moving from the center to the right end, the welding current values at P _R or P _R1 , P _R2 ,..., P _Ro are moved from the right end to the center by i _RF or i _RF1 , i _RF2 ,..., i _RFo . In the process, the welding current value at P _R or P _R1 , P _R2 , ..., P _Ro is i _RS or _{i RS1} , i _RS2 , ..., i _RSo
The difference between i _LF and S _L (=i _LF −i _LS ) or i _LS1 , i _LS2
，
The difference between the added values of i _LF1 , i _LF2 , ..., i _{LFo with respect to the added values of ..., i LSo is} S _L (=i _LF1 +i _LF2 +...+i _LFo −i _LS1 −i _LS2 −
…−i _LSo ), the difference of i _RF with respect to i _RS is S _R (=i _RF − i _RS ) or i _RF1 with respect to the added value of i _RS1 , i _RS2 , …, i _RSo ,
The difference between the added values of i _RF2 ,...,i _RFo is S _R (=i _RF1 +i _RF2 +...
+i _RFo −i _RS1 −i _RS2 −…−i _RSo ), the welding torch weaving amplitude center position is controlled according to the value of the difference S _A (=S _L −S _R ) between S _L and S _R or, in addition, the sum value S _B of S _L and S _R (=S _L +
This is a consumable electrode type arc welding method characterized by controlling the weld bead height to be constant according to S _R ). Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. (Function) Figure 1 shows the results of welding using a welding torch 8 perpendicular to the plane of the paper while weaving a steel plate 1 with a V-groove in the left and right directions using a constant voltage DC power supply 2. In order to observe how the welding current changes with respect to the amplitude of weaving, the welding current was detected by shunt 4 in an experimental device, and the signal was input to the vertical axis (Y axis) of synchroscope 9. The amplitude of is converted to voltage by potentiometer 5 and battery 6, and the synchroscope 9
is input to the horizontal axis (X-axis) of Note that 3 is a wire feeding device and 7 is a welding wire. Figure 2 shows the synchroscope screen, controllability evaluation, and bead appearance evaluation showing the change in welding current with respect to weaving amplitude when downward welding is performed under the following welding conditions using this experimental equipment and the weaving amplitude is changed. Shown below. Steel plate: JIS G3101 equivalent welding structural steel welding wire: JIS Z3312 equivalent steel wire 1.6φ Shielding gas: Ar80%CO ₂ 20% Bevel angle: 40° Root width: 5mm Weaving amplitude: 4mm, 6mm, 8mm Weaving period: 0.5sec Welding current: 350A Welding voltage: 31V Welding speed: 35cm/min Furthermore, using this experimental equipment, downward welding was performed under the following welding conditions, the root width r was varied, and the center of the weaving amplitude was centered at the groove center. Figure 5 shows the synchroscope screen showing the change in welding current with respect to the weaving amplitude when the weaving amplitude is varied by 2 mm from the weaving amplitude, and the torch and welding wire positions at the time of the weaving amplitude with respect to the groove. Steel plate: JIS G3101 equivalent welding structural steel Welding wire: JIS Z3312 equivalent welding wire 1.6φ Shielding gas: Ar80%, CO ₂ 20% Bevel angle: 50° Root width: 8, 10, 12mm Weaving amplitude: 10mm Weaving period :1sec Welding current: 400A Welding voltage: 33V Welding speed: 30cm/min The welding current changes with respect to the weaving amplitude as shown in Figure 2, but the process of change in welding current during one weaving amplitude cycle is explained conceptually. Figures 3 and 4 show that the tip of the welding wire is connected from the left end T ₃ of the groove of steel plate 1 to the center as shown in Figure 3.
Welding currents i ₄ , i ₁ , i ₂ during the process of passing through T ₁ and reaching stone edge T ₂
As shown in FIG. 4, the welding currents i ₂ , i 3 , and i ₄ are used during welding when the tip of the welding wire 7 moves from the right end T ₂ of the groove of the steel plate ₁ to the center T ₁ and the left end T ₃ . Such welding current changes are repeated. As can be seen from FIGS. 3 and 4, the welding current during the process in which the tip of the welding wire 7 travels from the center T1 of the groove of the steel plate ₁ to the left end _T3 is the welding current in the process from the left end _T3 to the center _T1 . , and similarly from center T ₁ to stone edge T ₂
The welding current in the process from the right end _T2 to the center T1 tends to be larger than the welding current in the process from the right end T2 to the center _T1 . Therefore, the welding current integrated value I _L1 during the process in which the tip of the welding wire 7 reaches from the center T ₁ of the groove of the steel plate 1 to the left end T ₃
(Area surrounded by T ₁ , T ₃ , i ₄ , i ₃ in Figure 4)
and the integrated welding current value I _L2 (area surrounded by T ₁ , T ₃ , i ₄ , i ₁ in Fig. 3) in the process from the left end T ₃ to the center T ₁ are not equal and I _L1 −I There is a tendency for _L2 > 0. S _L in Figure 2 shows this difference. Also, the tip of the welding wire 7 is at the center of the groove of the steel plate 1.
Integrated value of welding current I _R1 during the process from T ₁ to right end T ₂
(area surrounded by T ₁ , T ₂ , i ₂ , i ₁ in Figure 3) and the integrated value of welding current I _R2 in the process from the right end T ₂ to the center T ₁
(Area surrounded by T ₁ , T ₂ , i ₂ , i ₃ in Figure 4)
It can be seen that they are not equal and there is a tendency for I _R1 −I _R2 >0. The S _R in Figure 2 shows this difference. What should be noted here is that it was thought that the change in welding current was caused by a change in the distance between the chip and the base metal, but in reality, the tip of the welding wire 7 is at the left end of the groove in the steel plate 1. Or, the welding current is higher in the process of approaching the right end, that is, the process in which the distance between the chip and the base metal becomes smaller, than in the process in which the tip of the welding wire 7 approaches the center of the groove, that is, the process in which the distance between the chip and the base metal becomes larger. It turns out that it is not just the distance between the chips and the base metal. The reason for this phenomenon is not necessarily clear, but when a speed that reduces the distance between the chips and the base material is added to the wire feeding at a constant speed, the wire feeding speed appears to increase, and the distance between the chips and the base material also increases. If a speed is added that increases the wire feeding speed, it is thought that the wire feeding speed will apparently decrease. Generally, as the wire feeding speed increases, the welding current tends to increase. Therefore, the welding current integrated value I L1 or I R1 in the process of approaching the left end T ₃ or right end T ₂ of the weaving amplitude from the center T 1 is the _same as the welding current integrated value I _L1 or I _R1 in the process of approaching the center T ₁ from the left end T ₃ or right end T ₂ of the groove. It is considered that the welding current integrated value I _L2 or I _R2 is larger. Now, when comparing S _L and S _R , Fig. 5 a, c,
When the center of weaving amplitude is at the center of the groove as shown in e, S _L and S _R are approximately equal. However, when the center of the weaving amplitude moves to the left side of the groove as shown in FIGS. 5b, d, and f, S _L >S _R. Similarly, when the center of the weaving amplitude moves to the right side of the groove, S _L < S _R. Therefore, the difference of S _L with respect to S _R
By controlling S _A to move the center of the weaving amplitude to the right or left by setting S _A >0 or S _A <0, it is possible to control the weld line so that it does not form. Depending on the welding conditions, there is almost no difference in the current value during the process of the torch moving left and right at the center of the weaving, so it is not necessary to measure the integrated value of the welding current over the entire width of the weaving as described above. Welding line tracing control can also be performed simply by comparing the current values within 3 mm from both ends of the weaving. That is, welding wire 7
The welding current value i _LF or i _LF1 , i LF2 ,... at the position P _L or P L1 , P _L2 ,..., P _Lo during _the process in which the tip of the groove reaches from the center T ₁ of the steel plate ₁ to the _{left end T 3} ,i _LFo and leftmost T ₃
P _L in the process from to center T ₁ or P _L1 , P _L2 ,...,
Welding current value i _LS at position P _Lo or i _LS1 , i _LS2 ,…,
i _LSo are not equal i _LF −i _LS >0 or i _LF1 −i _LS1 >0,
There is a tendency that i _LF2 −i _LS2 >0,..., i _LFo −i _LSo >0.
Also, the tip of the welding wire 7 is at the center of the groove of the steel plate 1.
P _R in the process from T ₁ to the right end T ₂ or P _R1 , P _R2 ,
..., welding current value i _RF at position P _Ro or i _RF1 , i _RF2 ,
..., i _RFo and the welding current value i _RS or i _RS1 i RS2 , ..., i RSo at the position P _R or P _R1 , P _R2 , ..., P _Ro in the process from the right end _{T 2} to the center _{T 1} are equal i _RF −i _RS ＞0 or i _RF1 −i _RS1 ＞0, i _RF2 −i _RS2 ＞0,...i _RFo −i _RSo ＞
There is a tendency of 0. Groove profile control is possible by the above means, but if the weld bead height fluctuates greatly due to fluctuations in the root width and it becomes necessary to control this, the bead height can be controlled as follows. can be controlled. First, if we compare a and c or c and e in Fig. 5, as the root width r increases, S _L and S _R become smaller, so S _L and S _R
The added value S _B becomes smaller. Also, as the root width r becomes smaller, S _L and S _R become larger, so
S _B becomes larger. Therefore, it can be seen that when welding is performed while keeping the weaving amplitude constant, it is possible to detect changes in the root width from fluctuations in S _B. Also, Figure 2 above shows the change in welding current with respect to the weaving amplitude when the weaving amplitude is changed with the root width r = 5 mm, but when the weaving amplitude is set to 8 mm, S _L and S _R becomes large, and although the controllability is good, the bead appearance becomes poor. Also, when the weaving amplitude is set to 4 mm,
Although S _L and S _R become smaller and controllability becomes poorer, the bead appearance becomes better. Therefore, the optimal weaving amplitude that satisfies both controllability and bead appearance is 6 mm in the case of Fig. 2, and there is an optimal weaving amplitude for each root width r, and at that time S _L and S _R
The value of the added value S _B can be determined experimentally as the threshold value S _K of the weaving amplitude with respect to the route width r. Therefore, when the value of S _B becomes larger than the threshold value S _K , it can be determined that the root width r has become smaller, and the welding speed is increased or the wire feeding speed is decreased to reduce the welding rate per unit length. By reducing the amount of metal and reducing the weaving amplitude, the bead height can be controlled to be constant. If S _B is smaller than the threshold value S _K , it can be determined that the root width r has increased, so the welding speed should be reduced or the wire feeding speed should be increased to reduce the amount of deposited metal per unit length. By increasing the weaving amount and increasing the weaving amplitude, it is possible to control the bead height to be constant. In the above control, depending on the welding conditions, the bead height may be kept constant based on the measurement of the current value within 3 mm from both ends of the weaving, that is, according to the value of S _B , the sum of S _L and S _R. It is possible to control the Next, FIG. 6 is a configuration diagram showing one embodiment of a welding device for embodying the method of the present invention, and shows a speed-controllable running cart 10 running on a rail 11 installed on a steel plate 1, weaving period, and amplitude. and a welding torch 8 with a profile control function, and a controller 16 for controlling the welding torch 8. The controller 16 receives signals from the output of the shunt 4 disposed between the welding power source 2 and the welding torch 8 and the output of the welding torch position detector 15, and controls the slider motor 12, weaving motor 13, and truck motor 14. This is a device that automatically adjusts the weaving profile, weaving period/amplitude, and welding speed appropriately. Control operations during welding include suitably amplifying the welding current signal input from the shunt 4 at the same time as the start of welding through the amplifier 24, and inputting the amplified signal to the detector 25. On the other hand, the welding torch position data input from the welding torch position detector 15 and the weaving amplitude setting value (the weaving amplitude setting value initially set in the manual input device 20 and the weaving amplitude setting value in the amplitude setting device 22 before welding start) are The timing signal is input to a timing generator 23 to generate a timing signal for detecting a welding current, and the timing signal is input to a detector 25. The detector 25 detects the welding current at this timing, and inputs the welding current to the memory 26. The memory 26 classifies which position of the welding current value in the weaving amplitude process this welding current value is based on the signal from the timing generator. and store it in a predetermined location. When the data for one weaving cycle is stored, each data is output to the calculator 29, and the calculator 29 calculates S _L , R _R , S _A or further S _B . The calculator 29 outputs the calculation result S _A to the slider position setter 27, and the slider position setter 27 outputs the control direction and control amount according to the motor controller 18 according to the S _A to drive the slider motor 12. Performs tracing control. In addition, when controlling the weld bead height, the weaving period, amplitude setting device 22 and welding speed setting device 28 output the respective setting values set with the manual input devices 20 and 21 before welding start from the calculator 29. The weaving motor 13 and truck motor 14 are controlled through the motor controllers 17 and 19, and the weaving period, amplitude, and traveling truck speed are adjusted to maintain a constant weld bead height and a good bead shape _. do. By repeating the above operations, it is possible to perform automatic control so that the weld line is shaped and, if necessary, the weld bead height is kept constant. Although not particularly shown, a low-pass filter that selectively passes low-frequency components of the welding current signal is connected between the shunt 4 and the amplifier 24 to eliminate ripples and welding spatter that occur when the welding power source 3 is rectified. Noise caused by fluctuations in the welding current during welding can be reduced, and automatic control can be performed so that the welding line profile becomes more stable or the welding bead height remains constant. Next, examples of the present invention will be described. (Example) Welding was performed using the method of the present invention and the conventional method and compared in cases where the center of the weaving amplitude deviated from the weld line and the profile varied, and where the groove width varied. The experimental apparatus shown in FIG. 6 is used, and in the method of the present invention, the timing generator 23 is adjusted so that in the process from the center to the left end or from the center to the right end of the weaving amplitude, the distance between the center and the left end or the center and the right end is equidistant. Welding current values at 8 points i _L0 ~ i _L7 or i _R0 ~
i Collect _R7 and calculate the sum of these values as the welding current integrated value.
I _L1 or I _R1 (I _L1 =i _L0 +i _L1 +i _L2 +i _L3 +i _L4 +i _L5 +i
_L6
+i _L7 ,I _R1 =i _R0 +i _R1 +i _R2 +i _R3 +i _R4 +i _R5 +i _R6 +i _R7
)
And so. Similarly, welding current values at 8 points equidistant including the left end and center or right end and center in the process from the left end to the center or from the right end to the center of the weaving amplitude i _L8
~i _L15 or i _R8 ~i _R15 is sampled and this added value is used as the welding current integrated value I _L2 or I _R2 (I _L2 = i _L8 + i _L9 + i _L10 + i _L11
+
i _L12 +i _L13 +i _L14 +i _L15 ,I _R2 =i _R8 +i _R9 +i _R10 +i _R11
+
i _R12 + i _R13 + i _R14 + i _R15 ). This I _L1 , I _R1 , I _L2
，
Calculate S _A and S _B from I _R2 , and depending on the value of S _A ,
The center position of the weaving amplitude was controlled, and the weaving amplitude and welding speed or welding current were controlled according to the value of S _B. Furthermore, adjust the timing generator 23 to set P _L to 1 mm inside from the left end of the weaving amplitude, or 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6 from the left end.
mm inside P _L1 , P _L2 , P _L3 , P _L4 , P _L5 , P _L6 , P _L7 ,
P _L8 was set. Similarly, set P _R 1mm inward from the right end of the weaving amplitude, or 0.2, 0.4,
0.6, 0.8, 1.0, 1.2, 1.4, 1.6mm inside P _R1 , P _R2 ,
P _R3 , P _R4 , P _R5 , P _R6 , P _R7 , and P _R8 were set. Welding current value i _LF or _{i LF1} , _{i LF2} in the process from the center of the weaving amplitude to the left end at the position of _{P L or} P _L1 , P _L2 , P _L3 , P _L4 , P _L5 , P _L6 , P _L7 , P _L8 ,i _LF3 ,
i _LF4 , i _LF5 , i _LF6 , i _LF7 , i _LF8 are the welding current values i _LS or i _LS1 during the process from the left end of the weaving amplitude to the center,
i _LS2 , i _LS3 , i _LS4 , i _LS5 , i _LS6 , i _LS7 , and i _LS8 were collected.
Similarly, P _R or P _R1 , P _R2 , P _R3 , P _R4 , P _R5 ,
Welding current _{value i RF or}
i _RF1 , i _RF2 , i _RF3 , i _RF4 , i _RF5 , i _RF6 , i _RF7 , i _RF8 is the welding current value i _RS from the right end to the center of the weaving amplitude
or i _RS1 , i _RS2 , i _RS3 , i _RS4 , i _RS5 , i _RS6 , i _RS7 , i _R
S8
was collected. From these welding current values, calculator 2
9 to calculate S _L and S _R (S _L = i _LF −i _LS or S _L = i _LF1 +i _LF2 +i _LF3 +i _LF4 +i _LF5 +i _LF6 +i _LF7 +i _L
F8
−i _LS1 −i _LS2 −i _LS3 −i _LS4 −i _LS5 −i _LS6 −i _LS7 −i _LS8 and S _R =i _RF −i _RS or S _R =i _RF1 +i _RF2 +i _RF3 +i _RF4 +
i _RF5 +i _RF6 +i _RF7 +i _RF8 −i _RS1 −i _RS2 −i _RS3 −i _RS4 −i _R
S5 −
i _RS6 −i _RS7 −i _RS8 ), and further calculate S _A and S _B (S _A
= S _L − S _R and S _B = S _L + S _R ), the center position of the weaving amplitude is controlled according to the value of S _A , and the weaving amplitude and welding speed or welding current are controlled according to the value of S _B. I went there. In addition, the conventional method adjusts the timing generator 23 and changes the program of the calculator 29 to adjust the welding current I _L at the left end and right end of the weaving amplitude.
I _R was sampled, and the center position of the weaving amplitude was controlled according to the difference between I _R and I _L. The steel material used for welding was JIS G3101 equivalent welded structural steel. Figure 7 shows the center position of the groove changed by 10 mm in the section of 150 to 350 mm in the length direction of the groove, and Figure 8 shows the welded structural steel material equivalent to JIS G3101. The root width r is changed from 5 mm to 10 mm in the 150 to 350 mm section in the length direction of the tip. Further, welding was performed under the following conditions. Welding wire: JIS Z3312 equivalent steel wire 1.6φ Shielding gas: 400A Welding voltage: 33V Welding position: Downward Evaluation is based on the average value of the variation in the width and height directions of the weld bead, and the results are shown in Table 1. Shown below. As shown in Table 1, when welding according to the method of the present invention, the grooves shown in Figure 7, where the middle position of the groove is changed, and Figure 8, where the root width is changed, are in the width and height directions of the weld bead. The weld bead was stable and the fluctuation was small, resulting in a good weld bead. However, when welding using the conventional method, the groove shown in Figure 7 causes a large fluctuation in the width direction of the weld bead, resulting in an unstable weld bead, and the groove shown in Figure 8 results in an unstable weld bead.
Because there was a large variation in the height direction of the weld bead,
Both were defective.

【table】

[Table] (Effects of the Invention) As is clear from the above embodiments, the present invention focuses on the welding current change characteristics during weaving welding, and can control the movement of the center position of the weaving amplitude and the weld bead height based on it. Compared to conventional welding control methods, welding control is more stable and welding of better quality can be performed, which is an extremely significant contribution to the development of industry.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of the experimental equipment for observing changes in welding current with respect to weaving amplitude, and Figure 2 shows changes in welding current with respect to weaving amplitude observed with a synchroscope when weaving amplitude was changed, and welding on grooves. An explanatory diagram showing the torch and welding wire positions, controllability evaluation, and bead appearance evaluation. Fig. 3 is an explanatory diagram showing the welding current change in the process from the left end of the weaving amplitude to the right end. Fig. 4 is an explanatory diagram showing the welding current change from the right end of the weaving amplitude. An explanatory diagram showing the welding current change in the process of reaching the left end, Fig. 5 an explanatory diagram showing the welding current change when the profile fluctuates and when the groove width fluctuates, and Fig. 6 a schematic diagram of the welding device to which the present invention is applied. 7 and 8 are explanatory diagrams showing the dimensions and shapes of the steel plates and grooves used in the examples. DESCRIPTION OF SYMBOLS 1... V-grooved steel plate, 2... Welding power source, 3... Wire feeding device, 4... Shunt, 5... Potentio, 6... Battery, 7... Welding wire, 8... Welding torch, 9... ...Synchroscope, T ₁ ...Center of weaving amplitude, T ₂ ...Right end of weaving amplitude,
T ₃ ... left end of weaving amplitude, i ₁ ... welding current at center T ₁ in the process from left end T ₃ of weaving amplitude to right end T ₂ , i ₂ ... right end T ₂ of weaving amplitude
Welding current at i ₃ ... right end of weaving amplitude
Welding current at the center T ₁ in the process from T ₂ to the left end T ₃ , i ₄ ... Welding current at the left end T ₃ of the weaving amplitude, I _L1 ... Welding current integrated value in the process of moving from the center to the left end of the weaving amplitude , I _R1 ... integrated value of welding current in the process of moving from the center to the right end of the weaving amplitude, I _L2 ... integrated value of welding current in the process of moving from the left end of the weaving amplitude to the center, I _R2 ...
The integrated value of the welding current in the process of moving from the right end to the center of the weaving amplitude, S _L ...the difference of I _L1 with respect to I _L2 or the difference of i _LF with respect to i _LS , or the added value of i _LS1 , i _LS2 , ..., i _LSo i _LF1 , i _LF2 ,...,..., i _LFo difference, S _R ...Difference of I _R1 to I _R2 or difference of i _RF to i _RS or addition of i _RS1 , i _RS2 ,..., i _RSo Difference between the addition values of i _RF1 , i _RF2 ,..., i _RFo for the values, 10...
... Traveling trolley, 11 ... Rail, 12 ... Slider motor, 13 ... Weaving motor, 14 ... Dolly motor, 15 ... Welding torch position detector, 16
...Controller, 17...Motor controller 1, 1
8...Motor controller 2, 19...Motor controller 3, 20...Manual input device 1, 2
1... Manual input device 2, 22... Weaving period, amplitude setting device, 23... Timing generator,
24...Amplifier, 25...Detector, 26...Memory device, 27...Slider position setting device, 28...Welding speed setting device, 29...Calculator, r...Route width.

Claims (1)

[Scope of Claims] 1 In consumable electrode arc welding in which welding is performed by following the welding line while weaving the welding torch from side to side, welding current integrated value I in the process of moving the welding torch from the center to the left end during the weaving amplitude period. _L1 ,
Integrated value of welding current in the process of moving from the center to the right end
I _R1 , integrated value of welding current in the process of moving the welding torch from the left end to the center I _L2 , integrated value of welding current in the process of moving from the right end to the center I _R2 , relative to I _L2
Let the difference of I _L1 be S _L (= I _L1 − I _L2 ), and let the difference of I _R1 with respect to I _R2 be S _R (= I _R1 − I _R2 ), then S _A is the difference of S _L with respect to S _R.
A consumable electrode type arc welding method characterized by controlling the movement of the weaving amplitude center position of a welding torch according to the value of (=S _L −S _R ). 2. In consumable electrode type arc welding in which welding is performed by following the welding line while weaving the welding torch left and right, the integrated value of welding current I _L1 during the process of the welding torch moving from the center to the left end during the weaving amplitude period,
Integrated value of welding current in the process of moving from the center to the right end
I _R1 , integrated value of welding current in the process of moving the welding torch from the left end to the center I _L2 , integrated value of welding current in the process of moving from the right end to the center I _R2 , relative to I _L2
Let the difference of I _L1 be S _L (= I _L1 − I _L2 ), and let the difference of I _R1 with respect to I _R2 be S _R (= I _R1 − I _R2 ), then S _A is the difference of S _L with respect to S _R.
(=S _L −S _R ), the weaving amplitude center position of the welding torch is controlled to move, and
A consumable electrode type arc welding method characterized by controlling the weld bead height to be constant according to the sum value S _B (=S _L + S _R ) of S _L and S _R. 3 In consumable electrode arc welding, in which welding is performed by following the welding line while weaving the welding torch left and right, the position of the left edge of the weaving is P _Lp , and the position 3 mm inside from the left edge is P _Ln , within the range from P _Lp to P _Ln . in
Let P _L or P _L1 , P _L2 ,..., P _Lo (n is an integer of 2 or more) be the position of any one or more points that are not equal to P _Lp and P _Ln , and also from the center of the weaving amplitude.
P _R or P _R1 , P _{R2 ,} the point on the right side of the weaving amplitude equal to the distance to P _L or P _L1 , P _L2 , ..., P _Lo
..., P _Ro , and in the process of the welding torch moving from the center to the left end during the weaving amplitude period, P _L or P _L1 ,
The welding current value at P _L2 ,..., P _Lo is i _LF or i _LF1 ,
i _LF2 ,…, i _LFo , the welding current value at P _L or P _L1 , P _L2 ,…, P _Lo in the process of the welding torch moving from the left end to the center is i _LS or i _LS1 , i _LS2 ,…, i _LSo , in the process of the welding torch moving from the center to the right end, the welding current values at P _R or P _R1 , P _R2 ,..., P _Ro are moved from the right end to the center by i _RF or i _RF1 , i _RF2 ,..., i _RFo . In the process, the welding current values at P _R or P _R1 , P _R2 ,..., P _Ro are defined as i _RS or i _RS1 , i _RS2 ,..., i _RSo , and the difference of i _LF with respect to i _LS is S _L (=i _LF − i _LS ) or I _LS1 , i _LS2 ,
The difference between the added values of i _LF1 , i _LF2 , ..., i _{LFo with respect to the added values of ..., i LSo is} S _L (=i _LF1 +i _LF2 +...+i _LFo −i _LS1 −i _LS2 −
…−i _LSo ) The difference of i _RF with respect to i _RS is S _R (=i _LF − i _RS ) or i _RF1 with respect to the added value of i _RS1 , i _RS2 , …, i _RSo ,
The difference between the added values of i _RF2 ,...i _RFo is S _R (=i _RF1 +i _RF2 +...+
i _RFo −i _RS1 −i _RS2 −…−i _RSo ), the weaving amplitude center position of the welding torch is controlled according to the value of the difference S _A (= S _L − S _R ) between S _L and S _R A consumable electrode type arc welding method characterized by: 4 In consumable electrode arc welding in which welding is performed by following the welding line while weaving the welding torch left and right, the position of the left end of the weaving is P _L0 , and the position 3 mm inside from the left end is P _Ln , and the range from P _Lp to P _Ln. The position of any one or more points that are not equal to P _Lp and P _Ln within is defined as P _L or P _L1 , P _L2 ,..., P _Lo (n is an integer of 2 or more), and similarly, the center of the weaving amplitude Let the point on the right side of the weaving amplitude equal to the distance from P _L or P _L1 , P _L2 ,…, P _Lo to P _R or P _R1 ,
Assuming that P _R2 ,..., P _{Ro ,} in the process of the welding torch moving from the center to the left end during the weaving amplitude period, P _L or P _L1 ,
The welding current value at P _L2 ,..., P _Lo is i _LF or i _LF1 ,
i _LF2 ,…, i _LFo , the welding current value at P _L or P _L1 , P _L2 ,…, P _Lo in the process of the welding torch moving from the left end to the center is i _LS or i _LS1 , i _LS2 ,…, i _LSo , in the process of the welding torch moving from the center to the right edge, the welding current value at P _R or P _R1 , P _R2 ,..., P _Ro is changed to i _RF or i _RF1 , i _RF2 ,..., i _RFo , moving from the stone edge to the center In the process, the welding current values at P _R or P _R1 , P _R2 , ..., P _Ro are i _RS or i _RS1 , i _RS2 , ..., i _RSo , and the difference of i _LF with respect to i _LS is S _L (=i _LF − i _LS ) or i _LS1 , i _LS2 ,
The difference between the added values of i _LF1 , i _LF2 , ..., i _{LFo with respect to the added values of ..., i LSo is} S _L (=i _LF1 +i _LF2 +...+i _LFo −i _LS1 −i _LS2 −
…−i _LSo ) The difference of i _RF with respect to i _RS is S _R (=i _RF − i _RS ) or i _RF1 with respect to the added value of i _RS1 , i _RS2 , …, i _RSo ,
The difference between the added values of i _RF2 ,...,i _RFo is S _R (=i _RF1 +i _RF2 +...
+i _RFo −i _RS1 −i _RS2 −…−i _RSo ), the welding torch weaving amplitude center position is controlled according to the value of the difference S _A (=S _L −S _R ) between S _L and S _R A consumable electrode type arc welding method characterized in that the weld bead height is controlled to be constant according to the added value S _B (=S _L + S _R ) of S _L and S _R.