JPS58110179A - Monitoring method for shielding state in consumable electrode type gas shielded arc welding - Google Patents

Abstract

PURPOSE:To make the monitoring of impurities in a shielding gas possible by storing the welding current of the time when no impurities are contained in the shielding gas as functions of welding voltage and the feed speed of a wire and comparing the same with the values in the stage of actual welding. CONSTITUTION:The welding current, the voltage between a chip 4 and objects 5 to be welded, and the feed speed of a wire 3 in the state in which no impurities are contained in a shielding gas are measured. The welding current in the stage of non-consumable electrode type gas shielded arc welding in the above- described state is stored in an arithmetic unit 19 as functions of the above- described voltage and feed speed. The welding current, the voltage between the chip 4 and the objects 5, and the feed speed of the wire 3 in the stage of actual welding are respectively detected. The detected values are inputted to the unit 19, which operates the relations with the functions stored therein. Thus the impurities in the shielding gas are monitored in accordance with the difference in the functions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present disclosure relates to a shield condition monitoring method for consumable electrode type gas shielded arc welding.

In gas-shielded arc welding, the gas-shielding condition has a great influence on the welding result, so it is necessary to monitor the gas-shielding condition.The conventional monitoring method is to perform spectroscopic analysis of the arc light to determine the amount of gas contained in the shielding gas. There is a method of monitoring the presence or absence of impurities contained in the shielding gas by detecting the wavelength of the emission or absorption spectrum of the elements or molecules contained in the shielding gas.

However, this method requires the arc light to be guided stably and reliably to the detector, and has the disadvantage of being limited to the welding process due to restrictions on lighting equipment. As a result of intensive research, we focused on the fact that the current value changes depending on the shielding state. In other words, Figures 2 and 3 show the wire feed rate when welding using aluminum alloy for the workpiece and welding wire. Figure 2 shows the relationship between welding current and Sν voltage using a meter that measures the feeding speed.
This shows the case where 400 ppm of H20f is mixed in r. f
As, bxtj in the running diagram: wire feeding speed l is 600 cI
R/min, al.

bl is 700cl11/mf s al
, Jij800ap+/n+ln
s”4mb4 is 900 D11/win% J
, J is 101000c/! The case of II 1 rh is shown respectively.

As is clear from comparing Figures 2 and 3 at the same wire feeding speed, when running with H2O mixed, the curve S
shifts to the right side, that is, to the welding current where the welding current is high.

The present invention has been made by paying attention to the above findings, and its purpose is to calculate actual welding current and calculated melt Il.
It is an object of the present invention to provide a shield condition monitoring method for consumable electrode type gas shield arc welding that can easily monitor the shield condition m in real time without restricting the welding work by comparing the current i with the current i.

That is, the present invention calculates in advance the welding current of consumable electrode type gas shielded arc welding in a state where the shielding gas does not contain impurities as a function of the voltage between the tip and the workpiece and the wire feeding speed, and calculates the welding current using a calculator. Then, during actual welding, the welding current, the voltage between the tip and the workpiece, and the wire feeding speed are detected respectively, and these detectors are input to the above calculator to calculate the function stored here. A consumable electrode method is a method for monitoring the shielding condition of shielded arc welding, which is characterized by calculating the relationship between the shielding gas and the shielding gas and monitoring the properties of the shielding gas based on the difference in the function resulting from this calculation.

The present invention will be explained below by taking as an example an A/alloy MIG Jt rice using Alkon gas as a shielding gas.

Fig. 1 shows a block diagram showing a welding device and a shield state detection device.◇ This welding device drives a feed roller 2 with an electric motor 1 to send a welding wire 3 through a tip 4 toward a workpiece 5.
A welding power source 6 applies stain pressure between the tip 4 through which the welding wire J is inserted and the workpiece 5, and argon gas 9 is introduced from the shield gas supply pipe 8 to the shield nozzle 1 surrounding the tip 4. , A, - Welding is performed by shielding the weld metal Is and the weld metal horn from the atmosphere.

The shield state detection device includes a rotation amount detector 12 such as a low rotation encoder attached to the feed roller 2.
The rotational speed of the welding wire 3, that is, the feeding speed of the welding wire 3 is detected, and this detection signal is input to the A/I converter 14 via the amplifier 13. The welding current *' of the electric circuit that applies pressure to the tip 4 and the workpiece 5 is detected by the shunt 15, and this detection signal is input to the A/Dg converter 14 by installing an amplifier 16. . Also, the welding voltage is detected by the voltage divider 11, and this detection signal is input to the A/D converter 14 via the amplifier 18.◎A/D
The i-converter 14 converts the wire feed speed, welding current, and welding voltage signals into digital signals, and converts them into digital signals to be sent to a calculator 19 such as a computer S.
The 0 calculation unit 19 inputs the information that welding wi when the shield does not contain any impurities is between the tip 4 and the workpiece 5.
is stored as a function of the voltage between and the wire feed speed, and the actually input wire feed speed, Melt 1
The relationship between the detected value of current and welding voltage and this function is stored and calculated.
This monitors the properties of shielding gas.

That is, as is clear from FIGS. 2 and 3, welding flow W, welding voltage V, and wire feed 2! There is approximately a certain functional relationship between l1 degrees ν.

The relationship when there is no impurity in the shielding gas is 1-/(V, Y)...(1) The relationship f when the shielding gas contains moisture is 11,
=f/(■l, 9')...It is assumed that it is expressed as (2).

If the welding current is the same (v=v') and the wire feeding speed is the same (ma=・豐'), then welding is equal to I (I').

Therefore, during welding, the welding voltage (2) and the wire feed speed (Y) are detected, and the welding tir is determined from the above equation (1) assuming that the shielding atmosphere is completely stuttering. Next is this welding current ■ and actual welding.

Flow! . Compare with.

If I # IH, the shielding condition is good, and i
(If it is 1°, it means that impurities (moisture in this case) are mixed into the shielding atmosphere.

The computing unit 19 thus detects the welding current ■m', the welding voltage V, and the wire feeding speed fν, and calculates the relationship S between these to determine whether the shielding state is true or not.

As explained above, according to the present invention, since the welding current, welding voltage, and wire feed speed are used as information on the shield state, these can be easily detected, and round welding work that does not require detection near the arc can be performed. Don't get in the way. Moreover, the wire feeding speed is constantly changing, but since this can be directly detected and the welding speed can be determined as a wave speed, the shield condition 11 can be accurately monitored.@Also, this method allows the shield condition to be monitored instantly during welding. It has a remarkable effect.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing an example of a shielded 1m monitoring method for consumable electrode type gas shielded arc welding, and Figure 2 is the relationship between welding current and welding voltage in an argon atmosphere using wire feed speed as a parameter. Figure 3 is a diagram showing the y-coupling of the welding current and welding voltage when the wire feeding speed is adjusted to 9 meters and moisture is mixed into the argon atmosphere. 2... Feeding roller, 3... Fusing wire, 4... Chip, 5... Work to be welded, 6... Welding source, 1... Shield nozzle, 8... Shield Gas supply pipe, 9... Aldine gas, 10... Arc,
11... Weld metal, 12... Rotation amount detector, 13=
16.18...Amplifier, 14...A/Df converter, 1
5...Molecular Ar E, 11...Voltage divider, 19...
・Arithmetic unit.

Claims (1)

[Claims] The sI & ws of consumable electrode type gas shielded arc welding in a state where the shielding gas does not contain any impurities is determined in advance as a function of the voltage and wire feeding speed between the J and D and the workpiece and is stored in the calculator. Then, during actual welding, the welding wi, the voltage between the tip and the workpiece, and the wire feeding speed are detected, respectively, and these detected values are input to the above-mentioned calculator to calculate the stored lll number and A shield condition monitoring method for consumable electrode type gas shield arc welding, characterized by calculating the relationship between the following and monitoring the properties of the shield gas based on the difference in functions resulting from this calculation.