JPS58110180A - Monitoring method for shielding state in consumable electrode type gas shielded arc welding - Google Patents

Abstract

PURPOSE:To monitor shielding states accurately without limiting welding works by comparing the welding current determined by operation from welding voltage and the feed speed of a wire and the actual welding current. CONSTITUTION:The welding voltage between objects 5 to be welded and a chip 4 and the feed speed of a wire 3 obtained from a controller 12 for feed speed of a consumable electrode are inputted to a calculating device 16 which operates welding current. The calculated welding current and the actual welding current detected with a shunt 31 are inputted to a controller 15. The welding current operated with the controller 15 and the actual welding current are compared and the shielding state of a welding arc atmosphere is monitored.

Description

[Detailed Description of the Invention] The present invention relates to a shield condition monitoring method for consumable electrode type gas shielded arc welding.・As a conventional supervision method, spectroscopic analysis of arc light is performed to determine the wavelength of the emission or absorption spectral of molecules in the elements contained in the shielding gas [1].
There is a method of monitoring the presence or absence of impurities contained in the shielding gas.

However, this method has the disadvantage that it is necessary to stably and reliably guide the arc light to the detector, and that the welding work is restricted due to restrictions on the lighting device.

In order to eliminate this drawback, the inventor of the present invention carried out research on the welding wire and focused on the fact that the tff value changes depending on the shielding state. Figure 2 shows the wedge relationship between welding electrophoresis and welding voltage using the wire feed speed as a parameter when welding is performed using aluminum alloy. The figure shows 400 pp of H2O in Ar.
◎Also in the figure shows the case where M is mixed.

bttl wire feeding speed is 600 am/mf sa
m * f is 700 cHI/min % as *
BBS 800 tysr/min.

Hatake 4 sb4 Fi9 0 03/rain s
The cases of 1m and 11000c/m1no are shown, respectively.

As is clear from comparing Figures 2 and 3 at the same wire feeding speed, when H2O is mixed, song 1
1N is on the right - that is, the welding is shifted to 111 where the flow is higher. The present invention was made with attention to the above knowledge, and its purpose is to compare the actual welding current and the welding radio wave based on the calculated %. By doing so, it is an object of the present invention to obtain a shield condition monitoring method for consumable 11-electrode gas shield arc welding, which allows the shield condition to be easily monitored in real time without restricting welding work.

That is, the present invention calculates the welding current from the voltage between the workpiece and the tip in consumable electrode type gas-shielded arc welding, and the wire feed speed obtained from the electrode feed speed control device. This is a method for monitoring the shield state of consumable electrode type gas shield arc welding, which is characterized in that the shield state I11 is monitored by comparing this calculated value with the actual welding sweat value during welding.

The present invention will be explained below by taking as an example MIG welding of a 9k1 alloy using argon gas as a shielding gas.

FIG. 1 is a professional Kudaiadaram showing a welding device and a shield state detection device.

This welding device drives a feed roller 2 with an electric Ia1 to feed a welding wire 3 through a tip 4 in a direction of a workpiece 5, and welds between a tip 4 through which the welding wire 3 is inserted and a workpiece 5. Welding is performed by applying a voltage from a power source 6, and introducing aldine gas 9 from a shield gas supply pipe 8 to a shield nozzle 1 surrounding the chip 4, shielding the arc 1o and the weld metal 11 from the atmosphere. In this case, the drive control of the electric motor 2, that is, the control of the feed speed of the welding wire S, is as follows.
This is performed by the feed speed control device 12. The shield state detection device is provided with a shunt 13 and a voltage divider 14 in the electric circuit that applies voltage to the tip 4 and the workpiece 5, and the voltage from the shunt 13 is signal to controller J5, voltage divider 14
1) is input to the controller 111 via the performance device 16.

In addition, a feeding chain is provided to adjust the rotational speed of the electric motor 10.
A signal from the J controller 12 is input to the arithmetic unit J6. Furthermore, the signal from the controller 15 is input to a lamp and a display 11 of the first day.

In the present invention, the welding voltage between the workpiece 5 and the tip 4 is detected by the voltage divider 14, and this is input to the calculator IgK. Nine outputs are input to the calculator 16 in proportion to the feed speed. The calculator I6 calculates the melt *11II from the welding voltage, wire, and feeding speed based on the relationship shown in FIG. 2. Next, the calculated welding current ■. and I detected by the shunt 13
I-contact 11 style! , are input to the controller 16. 11N11
1 unit is 15! , and r, and as shown in equation (1) below, welding current X distortion! . If the value is close to
Assuming that the atmosphere in which welding is currently being performed is free of impurities, the signal t is input to the display 11. Also, the welding current is input as shown in equation (2) below. , is a value far from the IC, it is assumed that the atmosphere in which welding is currently being performed is contaminated with impurities, and a signal is displayed on the display 11.
The 0 input to the display 11 indicates OII, -I, which issues an alarm.
el≦α ... (1) IIm-Ial>α
...(2) However, α is a value that takes into consideration the measurement difference in current and the calculation error. Also, if the impurity is water, I, )
t.

becomes.

In this way, calculate the required current IC and the actual welding current! m
As described above, according to the present invention, the shielding state of the welding arc atmosphere is detected by using the welding arc phenomenon. There is no need to set up a tube, and welding work is controlled @
Moreover, since it can be processed in real time, an alarm can be issued immediately if 1 shield is in a hurry.

Furthermore, although the wire feeding speed is always fluctuating, this can be detected and the welding speed can be calculated, so that the 7-rud shape 11 can be targeted. In particular, since the wire feed speed is detected using the signal from the feed speed side @-, it has remarkable effects such as not making the welding machine complicated.◎

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing an example of a shield condition monitoring method for consumable electrode type gas shielded arc welding, #! Figure 2 shows the relationship between welding voltage and welding voltage in a 9mr atmosphere using the wire feed speed tt parameter. Fig. 7- is a diagram showing the relationship between the welding voltage and the welding voltage when all moisture is mixed into the Ar atmosphere.
Electric motor-2... Feed row 2.3... Welding wire, 4
...chip, 5... workpiece, 6... welding power source,
r... Shield nozzle, 8... Shield gas supply pipe, 9... Aldegas, Jo... Arc, 11...
Weld metal %JJ... Feeding speed controller, 13... Shunting device, 14... Voltage divider, 15... Control 11 device, 16.
...Arithmetic unit, 11...Display device.

Claims (1)

[Claims] In consumable electrode type gas-shielded arc welding, the welding current is calculated from the voltage between the welding point and the tip and the wire feeding speed obtained from the feeding speed controller of the consumable electrode, and this calculated value and the welding time are calculated. A shield condition monitoring method for consumable electrode type gas shielded arc welding, characterized in that the shield condition is monitored by comparing the shield condition with an actual welding electric current fil.