JP2000102864A - Consumable electrode type arc welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an electrode and a molten metal pool of the welded material from being contacted and adhered during the process for moving the material to the next position after completion of one welding in automatic welding. SOLUTION: In a consumable electrode type arc welding method using a welding power of drooping characteristics or constant current characteristics, at the time of finishing welding, supply of the consumable electrode and the power supply from a welding power supply is stopped after a given finish processing. Then, after a given stopping time (Ta), a given voltage output is supplied again, and a welding power output is stopped after a predetermined supply time (Tb). Furthermore, after a predetermined stopping time (Tc), the restart and the stop for output supply of the welding power are repeated again during a given time (T2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a consumable electrode type arc welding method in which power is supplied from a welding power source having a drooping characteristic or a constant current characteristic to a consumable electrode. The present invention relates to an improvement in a method in which a voltage is again applied to an electrode for a certain period of time, and if the consumable electrode comes into contact with a work to be welded, fusing is performed by the applied voltage.

[0002]

2. Description of the Related Art In a consumable electrode type arc welding, a consumable electrode (hereinafter, referred to as an electrode wire) is supplied at a small amount even after a feed stop command due to the inertia of a feed mechanism at the end of welding. In order to prevent the welding material from entering the molten metal pool and being welded, the power supply from the welding power source is continued for a while after the command to stop the supply of the electrode wire by the welding stop command, and then cut off. The method and the welding end processing are adopted. This processing is generally called anti-stick processing.

[0003] However, when performing automatic welding by holding a welding torch on a robot or the like, the torch is often moved to a next welding position or a retracted position after one welding operation. If the curvature of the consumable electrode guide conduit changes following the movement, the electrode may come out of the tip of the torch by the amount of the change. When the torch moves in such a state, the electrode wire and the molten metal pond of the work to be welded may contact and be welded on the way.

Conventionally, in order to prevent such welding, power is supplied again from the welding power source to the electrode wire after the completion of the welding process, ie, after the completion of the anti-stick process, and when the electrode wire comes into contact with the workpiece. A system in which the electrode wire is melted by this electric power has been proposed.

FIG. 9 is a diagram showing changes in output current and voltage at the end of welding when the conventional welding method described above is carried out with the passage of time.

In FIG. 9, (A) is a command signal for starting welding. (B) shows the feed amount of the electrode wire, (C)
Is an example of a welding current waveform at this time, and (D) is a welding voltage waveform, which shows each welding voltage in the anti-stick processing period Tu and the welding release processing period Tr. Time t = t
When the welding start command signal disappears in Step 1, the power supply to the wire feed motor is stopped. However, even if the power supply to the wire feed motor is stopped, the electrode wire is fed while decelerating while rotating by inertia. Subsequently, the feeding of the electrode wires is stopped at time t = t2 shown in (B).

When the feed amount of the electrode wire decreases during the anti-stick processing period Tu, the welding current decreases. Also, after the anti-stick processing period Tu has elapsed, in the welding release processing for supplying power again from the welding power source to the electrode wire for the predetermined time Tr, when the electrode wire comes into contact with the workpiece as shown at time t = t3, An electric current flows by the electric power and blows the electrode wire.

[0008]

In the welding method shown in FIG. 9, it has been confirmed that when the electrode wire comes into contact with the work to be welded, the electrode wire can be blown off by the action of the welding release process. However, when a welding machine is used in combination with a robot, due to differences in welding postures, i.e., downward welding, downward welding, upward welding, etc., the burning from the tip of the electrode is not constant, and there is currently a large barracks.
It is difficult to balance the set length of the power supply period Tr for welding release with the length of the electrode wire protruding from the torch. Since the arc does not cut off naturally, the arc may reach the power supply tip of the torch and heat it in some cases.

Further, as another prior art, after the end of welding, that is, during the anti-stick processing period, it is determined whether an arc is generated or a short-circuit is generated. The output of the welding power source is cut off when t1 is satisfied, the output is again output after the set time t2, the output is cut off when the arc generation period Ta becomes equal to t1, and the same repetition is performed thereafter. Control method with improved anti-stick processing (JP-A-2-37)
965).

However, also in the above-mentioned conventional method, at the end of welding, welding end processing (anti-stick processing)
In the welding release process performed after the completion of the welding, a constant output is supplied for a certain period of time. Therefore, during the power supply period for the welding release process, the electrodes are substantially stopped, so the power supplied is When an arc is generated, the electrode burns up from the tip of the electrode, and if the set length of the power supply period and the length of the electrode protruding from the torch are not balanced, the arc reaches the power supply tip of the torch and burns it out. It has the same problem as the method. If this is to be prevented, it is necessary to use a constant voltage characteristic welding power source so that the arc will spontaneously disappear when the arc burns up and the arc voltage rises. Therefore, when using a constant current characteristic or a drooping characteristic as the welding power source, prepare a power source with a constant voltage characteristic separately for this welding release processing or devise a control method and change the constant voltage characteristic only during this period. It was necessary to change the control method so that it would be.

[0011]

According to a first aspect of the present invention, there is provided a consumable electrode type arc welding method for supplying power to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic.
At the end of welding, a predetermined end process is executed to stop the supply of the consumable electrode and the power supply from the welding power source, and after a predetermined stop time (Ta), a predetermined voltage is applied from the welding power source to the consumable electrode. The output is supplied, the output of the welding power supply is stopped after a predetermined supply time (Tb), and the output supply of the welding power supply is restarted and stopped for a predetermined time (T2) after a predetermined stop time (Tc). The present invention proposes a consumable electrode-type arc welding method that repeats for a while.

According to a second aspect of the present invention, in a consumable electrode type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic, a predetermined end process is executed at the end of welding. The supply of the consumable electrode and the power supply from the welding power supply are stopped to supply a predetermined voltage output from the welding power supply to the consumable electrode after a predetermined stop time (Ta). The output of the welding power source is stopped after a predetermined supply time (T4) since the occurrence of the arc, and the occurrence of the arc is monitored based on the change in the arc current and the output current. Proposes a consumable electrode type arc welding method in which the output of a welding power source is stopped after a predetermined time (T3 + Td) from the start of supply of the voltage to the consumable electrode.

According to a third aspect of the present invention, in a consumable electrode type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic, a predetermined end process is executed at the end of welding. The supply of the consumable electrode and the power supply from the welding power supply are stopped to supply a predetermined voltage output from the welding power supply to the consumable electrode after a predetermined stop time (Ta). And monitoring the presence or absence of an arc from the change in the output current. If no arc is detected, the output of the welding power source is stopped after a predetermined time (T6) after the supply of the voltage to the consumable electrode is started, When an arc is detected, the output of the welding power supply is stopped after a predetermined supply time (T4) from the detection of the arc, and after a predetermined stop time (Tc), the output of the welding power supply is restarted and the arc is stopped. In which it proposed a consumable electrode type arc welding method of repeating during the detection and arcing at the time of detecting a predetermined supply time of presence or absence of the occurrence (T4) after the welding power-supply output stop operation for a predetermined time of the output of the (T6).

According to a fourth aspect of the present invention, in a consumable electrode type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic, a predetermined end process is executed at the end of welding. The supply of the consumable electrode and the power supply from the welding power supply are stopped to supply a predetermined voltage output from the welding power supply to the consumable electrode after a predetermined stop time (Ta). The presence or absence of an arc is monitored based on the change in the output current and the output. When the arc is detected, the output of the welding power source is stopped after a predetermined supply time (T4) from the occurrence of the arc, and the arc is not detected. Stops the output of the welding power source after a predetermined time (Tb) after supplying the output of the predetermined voltage to the consumable electrode, and resumes the output power supply of the welding power source after a predetermined stop time (Tc). And a Output stopped after generating the detection after a predetermined supply time (T4), also a predetermined time the output stop after the predetermined time (Tb) when no occurrence of arc (T
The present invention proposes a consumable electrode type arc welding method that is repeated during 6).

According to a fifth aspect of the present invention, there is provided the consumable electrode according to any one of the third and fourth aspects, wherein the predetermined time (T6) is counted from the end of the predetermined stop time (Ta). It proposes an arc welding method.

[0016]

FIG. 1 is a connection diagram showing an example of an apparatus for performing a welding method according to the present invention. In FIG. 1, reference numeral 1 denotes a torch switch, which issues a welding start command signal. 2
Is an output setter that outputs a welding current setting signal S2a and a welding voltage setting signal S2e. Reference numeral 4 denotes a welding power source which has a drooping characteristic or a constant current characteristic. Reference numeral 3 denotes a driver circuit, which is a circuit for driving the welding power source 4.
5 is an output control circuit, 6 is a welding current detector,
The welding current detection signal Ib is input to the output control circuit 5. 7
Is a welding voltage detector which inputs a welding voltage detection signal Vb to the output control circuit 5 in the same manner as described above. 8 is a wire feed motor, and 9 is a wire feed roll. Reference numeral 10 denotes an electrode wire, and reference numeral 11 denotes a workpiece. The output control circuit 5 is a circuit that compares the welding current detection signal Ib with the welding current setting signal S2a of the output setting device 2 and modulates the pulse width according to the magnitude of the difference signal. The width-modulated output signal S10 is supplied to the driver circuit 3 to determine the output current value of the welding power source 4. Also, the welding voltage detection signal Vb is compared with the welding voltage setting signal S2e of the output setting device 2, and a wire feeding control speed signal S3 according to the magnitude of the difference signal is outputted to control the rotation of the wire feeding motor. Control. When the torch switch 1 is turned off from on, the anti-stick processing is executed, and when the processing is completed, an anti-stick processing end signal S4 is output.

Reference numeral 12 denotes a mono-multi vibrator, which outputs an output stop signal S5 for a predetermined time Ta from when the anti-stick processing end signal S4 is input.
Reference numeral 13 denotes a welding release processing circuit, which includes a monomultivibrator 14, a pulse generation circuit 15, and an AND gate 16, and outputs a welding release processing signal S8.

FIG. 2 is a diagram showing changes in output current and voltage at the end of welding in the apparatus shown in FIG. 1 over time. In FIG. 2, (A) is a torch switch 1
(B) shows the electrode wire 1
It indicates a feed rate of 0. (C) shows the welding current detection signal Ib of the welding current detector 6, and (D) shows the welding voltage detection signal Vb of the welding voltage detector 7. (E) shows the anti-stick processing end signal S4 of the output control circuit 5, and (F) shows the output stop signal S5 of the mono multivibrator 12.
(G) shows the output signal S6 of the mono-multi vibrator 14, (H) shows the output signal S7 of the pulse generation circuit 15, and (I) shows the welding release processing signal S8 of the welding release processing circuit 13.

In FIGS. 1 and 2, the torch switch 1
Is turned off, the welding start command signal S1 of the torch switch 1 becomes Low (hereinafter, referred to as L) as shown in FIG. A welding start command signal S1 is output to the output control circuit 5.
Is input at L, the output control circuit 5 executes the anti-stick processing, and outputs an anti-stick processing end signal S4 upon completion of the processing. On the other hand, the wire feed control signal S3 also becomes L, and the power supply to the wire feed motor 8 is stopped. When the power supply to the wire feed motor 8 is stopped, the wire feed speed is rapidly reduced but does not stop immediately, and the electrode wire 10 is continuously fed while the wire feed roll 9 is rotating due to inertia. The feeding of the electrode wire is stopped with a delay until time t2 shown in FIG.

In the anti-stick processing period (T1), the feed amount of the electrode wires is reduced, and as shown in FIG.
As shown in (C), the value of the welding current detection signal Ib decreases.

At time t = t3, when the anti-stick processing period (T1) ends and the end signal S4 is input to the mono multivibrator 12, as shown in FIG. The anti-stick processing end signal S4 is High (hereinafter, referred to as H).
At the same time, the operation is started, and during a predetermined stop time (Ta), an output stop signal S5 shown in FIG.

The mono-multi vibrator 14 starts operating at the same time as the output stop signal S5 falls to L, and operates for a predetermined period of time (weld release command period T2).
A welding release command signal S6 shown in (G) is output. Signal S
6 is input to the AND gate 16 and also to the pulse generation circuit 15. During the period when the signal S6 is output at H, the pulse generation circuit 15 operates to generate the pulse signal S7 shown in FIG. The signal is output and input to the AND gate 16.

The AND gate 16 receives the pulse signal S7 of the pulse generation circuit 15 and the output signal S6 of the mono-multivibrator 14, and outputs an H signal when both input signals are H.
It is output as the welding release processing signal S8 shown in (I). The welding release processing signal S8 is input to the output control circuit 5, and the output control circuit 5 outputs the output signal S10 and outputs a predetermined signal between the electrode wire 10 and the workpiece 11 during the period (Tb) when the input signal S8 is H. Supply voltage. At this time, the output period (Tb)
And the pause period (Tc) can be determined by setting the pulse generation circuit 15.

During the welding release command period (T2), when the electrode wire 10 comes into contact with the workpiece 11, the output signal S8 of the welding release processing circuit 13 becomes H (Tb).
A predetermined voltage is supplied from the welding power source 4 between the electrode wire 10 and the workpiece 11, and a current flows through the electrode wire 10 to blow it. 2C shows a welding current detection signal Ib when the electrode wire 10 is blown, FIG. 2D shows a welding voltage detection signal Vb when the electrode wire is blown, and FIG. Also indicates that a predetermined voltage is output when is open.

FIG. 3 is a connection diagram showing another example of an apparatus for performing the welding method of the present invention. In the figure, reference numeral 18 denotes a welding detection circuit, and a welding voltage detection signal V
b and the welding current detection signal Ib are input. Whether the electrode wire 10 is in a short-circuit state is detected based on whether the welding voltage detection signal Vb is lower than the reference value Vr, and whether or not the welding current detection signal Ib is lower than the reference value Ir. Is detected in a no-load state or a state in which a welding current is flowing. When Vb ≦ Vr and Ib ≧ Ir, the welding detection circuit 18 determines that the electrode wire 10 is in a welding state, and outputs a welding detection signal S14 of an H signal. In the figure, reference numeral 22 denotes a welding release processing circuit, which is composed of a welding detection signal S14 and an anti-stick processing end signal S4.
Signals are input. The other components have the same reference numerals as those of the embodiment shown in FIG. 1 and the detailed description thereof will be omitted.

The welding detection circuit 18 determines whether the electrode wire 10 is welded or opened.
9, a short-circuit detection circuit 20 and an AND gate 21. When an arc is generated in the electrode wire 10, the welding detection signal S14 is output as H.

The welding release processing circuit 22 includes a monomultivibrator 23, an AND gate 24, an inverter gate 2
5, an RS flip-flop 26, a monomultivibrator 27, a monomultivibrator 28, a monomultivibrator 29, an inverter gate 30, an AND gate 31, an inverter gate 48 and an OR gate 49, and a welding release processing signal S23. Is output.

FIG. 4 is a diagram showing changes in output current and voltage at the end of welding in the apparatus shown in FIG. 3 over time. In FIG. 4, (A) is a torch switch 1
(B) shows the electrode wire 1
It indicates a feed rate of 0. (C) shows the welding current detection signal Ib of the welding current detector 6, and (D) shows the welding voltage detection signal Vb of the welding voltage detector 7. (E) shows the anti-stick processing end signal S4 of the output control circuit 5, and (F) shows A.
It shows the output signal S14 of the ND gate 21 and becomes an H signal only during the arc generation period. (G) shows the output signal S15 of the monomultivibrator 23, (H) shows the output stop signal S18 of the monomultivibrator 27, and (I) shows the output signal S19 of the monomultivibrator 28.
(J) shows the output signal S17 of the inverter gate 25, (K) shows the output signal S22 of the AND gate 31, and (L) shows the output signal S23 of the welding release processing circuit 22. (M) shows the output signal S22 of the AND gate 31 when the arc is not detected, and (N) shows the output signal S2 of the welding release processing circuit 22 when the arc is not detected.
3 is shown.

3 and 4, the torch switch 1
Is turned off, the welding start command signal S1 of the torch switch 1 becomes L as shown in FIG. When the welding start command signal S1 is input to the output control circuit 5 at L, the output control circuit 5 executes an anti-stick process, and outputs an anti-stick process end signal S4 at the end. On the other hand, the wire feed control signal S3 becomes L at the same time as the fall of the welding start command signal S1, and operates in the same manner as in the embodiment shown in FIG. 1, and as shown in FIG. Supply stops.

When the anti-stick processing end signal S4 shown in FIG. 4E is input to the mono-multi vibrator 27, the mono-multi vibrator 27 starts operating at the same time as the anti-stick processing end signal S4 rises to H. , And outputs an output stop signal S18. The anti-stick processing end signal S4 is also input to the arc detection circuit 19 and the short-circuit detection circuit 20.

The arc detection circuit 19 receives the anti-stick processing end signal S4 and the welding current detection signal Ib as inputs,
The arc detection circuit 19 becomes operable simultaneously with the input of the anti-stick processing end signal S4. When the electrode wire 10 and the workpiece 11 come into contact with each other while the arc detection circuit 19 is operating, a welding current detection signal Ib shown in FIG. 4C is input to the arc detection circuit 19, and the arc detection circuit 19 is set in advance. The reference value Ir and the value of the welding current detection signal Ib are compared, and when Ib ≧ Ir, the arc detection signal S
12 is set to H and input to the AND gate 21.

An anti-stick processing end signal S4 and a welding voltage detection signal Vb are input to the short-circuit detection circuit 20,
The short-circuit detection circuit 20 becomes operable at the same time when the anti-stick processing end signal S4 is input as described above, and the electrode wire 10 and the work 1
4, the welding voltage detection signal Vb shown in FIG.
Compares a preset reference value Vr with the value of the welding voltage detection signal Vb, determines that a short circuit has occurred when Vb ≦ Vr, sets the short circuit detection signal S13 to L, and sets a signal S1 when Vb> Vr.
3 is set to H and input to the AND gate 21.

The AND gate 21 outputs an arc detection signal S12.
When both of the input signals H and H are H, it is determined that an arc has occurred, and an H signal is output as a welding detection signal S14 shown in FIG.

When the anti-stick processing end signal S4 is input to the mono-multi vibrator 27, the mono-multi vibrator 27 outputs the anti-stick processing end signal S4.
Rises to the H level, the operation is started at the same time, and during the predetermined stop time (Ta), the output stop signal S shown in FIG.
18 is output. The output stop signal S18 is input to the mono-multi vibrator 28, and the operation is started at the same time when the input signal S18 falls to L, and the output stop signal S18 is started for a predetermined time (T
During the period 3), the set signal S19 shown in FIG.
It is input to the D gate 24 and the OR gate 49.

When the welding detection signal S14 is input to the monomultivibrator 23, the monomultivibrator 23
Starts operation at the same time as the input signal S14 rises to H, and outputs an output signal S15 shown in FIG. 2 (G) for a predetermined time (T4). The AND gate 24 receives the input signal S15 and the set signal S19 as input, becomes H signal when both input signals are H, inverts the inverted signal at the inverter gate 25, and inputs the output signal S17 shown in FIG. I do. The set signal S 19 shown in FIG. 4I is input to the OR gate 49, and the same signal as the input signal is output from the OR gate 49 and input to the mono multivibrator 29. The input signal of the mono multivibrator 29 is L
At the same time, the operation starts, and an output signal S20 is output for a predetermined period of time (Td). The output signal S20 is inverted by the inverter gate 30 to become a signal S21 and input to the AND gate 31. The AND gate 31 receives the signal S17 and the signal S21, and when both input signals are at H, the signal becomes H signal.
The reset signal S22 shown in FIG. When the set signal S19 shown in FIG. 4 (I) is input to the set terminal S of the RS flip-flop 26, the operation starts at the same time as the input signal rises to H and the RS flip-flop 26
Is at H level. On the other hand, the reset terminal R is connected to FIG.
When the reset signal S22 shown in (K) is input, the RS flip-flop 26 is reset at the first rising of the input signal S22, the Q terminal becomes L, and the welding release processing signal S23 shown in FIG. Is output.

The welding release processing signal S23 is output from the output control circuit 5
And the output control circuit 5 outputs the welding release processing signal S23.
Outputs an output signal S10 during the period of H
A predetermined voltage is supplied between 0 and the workpiece 11. At this time, the supply time (T4) can be determined by setting the mono multivibrator 23.

When the electrode wire 10 does not come into contact with the workpiece 11 during the welding release command period (T3), FIG.
The welding detection signal S14 shown in (F) is not output, the output signal S15 of the monomultivibrator 23 remains at L, and the output signal S16 of the AND gate 24 also becomes L. Therefore, this output signal is inverted by the inverter gate 25. The signal S17 remains H. The output signal S20 of the mono-multivibrator 29, which starts operating at the same time as the output signal S19 of the mono-multivibrator 28 falls to L,
Is inverted by the inverter gate 30 to obtain an output signal S21.
After the output signal S19 of the mono-multi multivibrator 28 becomes L (T3), after a predetermined time (Td) when the output signal S21 of the inverter gate 30 becomes L, the signal becomes H after passing through the AND gate 31, and R The reset signal S22 shown in FIG. 4M is input to the reset terminal R of the
9, after the input signal first rises to H after the predetermined time (Td), the RS flip-flop 26 is reset and the Q terminal becomes L, and the welding release processing signal S23 shown in FIG. 4 (N) becomes (T3 + Td). ) Is output. Further, during the (T3 + Td), the electrode wire 10 and the work 1
1 and an arc is generated, the output signal S15 of the monomultivibrator 23 becomes H, so that the output signal of the AND gate 24 is also H, and the output of the inverter gate 25 is L.
The welding release processing signal S23 outputs an H signal during this time period (T4) of the mono-multi vibrator 23, similarly to the previous arc generation. The output signal S is output at the end of the fixed time (T3) of the monomultivibrator 28.
If 13 is L, a signal H obtained by inverting the signal at the inverter gate 48 is input to the OR gate 49, and the input signal of the mono-multivibrator 29 remains at H and does not start. When the short circuit is eliminated and the short circuit detection signal S13 becomes H, the output signal S12 of the mono multivibrator 19 at that time becomes H.
, The monomultivibrator 23 is activated and the arc period (T4) starts, and if the output signal S12 is L, R
The -S flip-flop 26 is reset and ends.

FIG. 5 is a connection diagram showing another example of an apparatus for performing the welding method of the present invention. In the figure, reference numeral 41 denotes a welding release processing circuit, which includes a mono multivibrator 17, a monomultivibrator 32 to a monomultivibrator 35,
It is composed of an inverter gate 36, an OR gate 37, a NAND gate 38, an AND gate 39, and an RS flip-flop 40, and receives two signals of a welding detection signal S14 and an anti-stick processing end signal S4. Other components have the same functions as those of the embodiment shown in FIGS. 1 and 3, and the detailed description thereof is omitted.

FIG. 6 is a diagram showing changes in output current and voltage at the end of welding in the apparatus shown in FIG. 5 over time. In FIG. 6, (A) is a torch switch 1
(B) shows the electrode wire 1
It indicates a feed rate of 0. (C) shows the welding current detection signal Ib of the welding current detector 6, and (D) shows the welding voltage detection signal Vb of the welding voltage detector 7. (E) shows the anti-stick processing end signal S4 of the output control circuit 5, and (F) shows the output stop signal S24 of the mono-multi vibrator 32. (G) shows the output signal S14 of the AND gate 21, which becomes the H signal only during the arc generation period. (H) shows the output signal S28 of the mono multivibrator 35,
(I) is an output signal S25 of the monomultivibrator 17.
Is shown. (J) shows the output signal S27 of the mono-multi vibrator 34, (K) shows the output signal S26 of the NAND gate 38, and (L) shows the output signal S29 of the welding release processing circuit 41. (M) shows the output signal S26 of the NAND gate 38 when the occurrence of an arc is not detected.
(N) shows the output signal S29 of the welding release processing circuit 41 when the arc is not detected.

The anti-stick processing end signal S 4 shown in FIG. 6E is input to the mono-multi vibrator 32 and also to the arc detecting circuit 19 and the short-circuit detecting circuit 20.

When the anti-stick processing end signal S4 is input to the mono-multi vibrator 32, the mono-multi vibrator 32 outputs the anti-stick processing end signal S4.
Rises to H and starts operation at the same time. During a predetermined stop time (Ta), the output stop signal S shown in FIG.
24 is output. The output stop signal S24 is input to the mono-multi vibrator 35, and starts operating at the same time as the input signal S24 falls to L, and the predetermined time (T
During the period 6), the output signal S28 shown in FIG. 6H is output and input to the NAND gate 38 and the AND gate 39. On the other hand, the mono-multi vibrator 33 has
The welding detection signal S14 shown in (G) is input. The mono-multi vibrator 33 starts operating at the same time as the welding detection signal S14 falls to H, outputs an output signal for a predetermined time (T4), and inputs the output signal to the mono-multi vibrator 17. The mono-multi vibrator 17 starts operating at the same time as the input signal falls to L, and outputs the output signal S2 shown in FIG. 6 (I) for a predetermined time (Tc).
5 is output, and the inverter gate 36 and the OR gate 37 are output.
To enter.

The OR gate 37 outputs signals S24 and S25.
Is input to the mono multivibrator 34 as an H signal when either of the input signals is H. The mono-multi vibrator 34 starts operating at the same time as the input signal falls to L, and operates for a predetermined period Te.
The set signal S27 shown in (J) is input to the set terminal S of the RS flip-flop 40.

A signal obtained by inverting the signal S28 shown in FIG. 6H and the output signal S25 shown in FIG. 6I by the inverter gate 36 is input to the NAND gate 38. When both input signals are H, the L signal is The reset signal S26 shown in FIG. 6K is output, and the RS flip-flop circuit 4
0 is input to the reset terminal R.

When the set signal S27 shown in FIG. 6 (J) is input to the set terminal S of the RS flip-flop 40, the operation starts at the same time as the input signal rises to H, and the operation of the RS flip-flop 40 is started. The Q terminal goes to H. On the other hand, when the reset signal S26 shown in FIG.
The flip-flop 40 is reset and the Q terminal becomes L. The AND gate 39 has an RS flip-flop 40
And the signal S28 is input, and when both input signals are H, the welding release processing signal S29 shown in FIG.

The welding release processing signal S29 is output from the output control circuit 5
And the output control circuit 5 outputs a welding release processing signal S29.
Outputs an output signal S10 during the period of H
A predetermined voltage is supplied between 0 and the workpiece 11. At this time, the welding release command period (T6) can be determined by setting the mono-multi vibrator 35.

When the electrode wire 10 does not come into contact with the workpiece 11 during the welding release command period (T6), FIG.
Is not output, the output signal of the monomultivibrator 33 remains L, and the output signal S25 of the monomultivibrator 17 also becomes L. This signal S25 is inverted by the inverter gate 36 to become an H signal. Input to NAND gate 38. NAND gate 3
8 receives the H signal and the signal S28 shown in FIG. 6 (H). When both signals are H, it becomes L and the signal S26 shown in FIG. 6 (M) is output. The signal S26 is input to the reset terminal R of the RS flip-flop 40, and the input signal S2
8 rises to H first, and at the same time, the RS flip-flop 40 is reset, the Q terminal becomes L, and the welding release processing signal S29 shown in FIG. 6 (N) is output during (T6).

FIG. 7 is a connection diagram showing another example of an apparatus for performing the welding method of the present invention. In the embodiment shown in the figure, reference numeral 42 denotes a welding release processing circuit, which is a monomultivibrator 17, a monomultivibrator 32 to a monomultivibrator 35, an inverter gate 36, an OR gate 37, a NAN.
D gate 38, AND gate 39, RS flip-flop 40, inverter gate 43, AND gate 44,
It comprises an inverter gate 45, an AND gate 46, and a pulse generation circuit 47, and receives two signals, a welding detection signal S14 and an anti-stick processing end signal S14. Other components have the same functions as those of the embodiment shown in FIGS. 1 and 3, and the detailed description thereof is omitted.

FIG. 8 is a diagram showing changes in output current and voltage at the end of welding in the apparatus shown in FIG. 7 over time. In FIG. 8, (A) is a torch switch 1
(B) shows the electrode wire 1
It indicates a feed rate of 0. (C) shows the welding current detection signal Ib of the welding current detector 6, and (D) shows the welding voltage detection signal Vb of the welding voltage detector 7. (E) shows the anti-stick processing end signal S4 of the output control circuit 5, and (F) shows the output signal S28 of the mono multivibrator 35.
(G) shows the output signal S14 of the AND gate 21, which becomes the H signal only during the arc generation period. (H) shows the output signal S30 of the AND gate 44, and (I) shows the output signal S31 of the inverter gate 45. (J) shows the output signal S29 of the AND gate 39, and (K) shows the output signal S32 of the welding release processing circuit 42. (L) is an output signal S29 of the AND gate 39 when no arc is detected.
(M) shows the output signal S31 of the inverter gate 45 when no arc is detected, and (N) shows the output signal S32 of the welding release processing circuit 42 when no arc is detected.

When the anti-stick processing end signal S4 shown in FIG. 8 (E) is input to the monostable multivibrator 32, the monostable multivibrator 32 starts its operation at the same time as the rise of the antistable processing end signal S4 and outputs the signal. The stop signal S24 is output for a predetermined stop time (Ta). On the other hand, the output stop signal S24 is input to the mono-multi vibrator 35 and starts to operate at the falling edge of the input signal S24, and during a predetermined time (T6) shown in FIG.
An output signal S28 shown in (F) is output and input to the NAND gate 38, the AND gate 39, and the AND gate 44.

When the welding detection signal S14 shown in FIG. 8 (G) is input to the inverter gate 43, the inverter gate 43 inverts the input signal and inputs the inverted signal to the AND gate 44. The AND gate 44 also receives the output signal S28 of the monomultivibrator 35 shown in FIG. 8 (F), outputs a reset signal S30 shown in FIG. 8 (H) as an H signal when both input signals are H, and generates a pulse. Input to the circuit 47.

In the pulse generation circuit 47, when the input signal S30 is H
When the signal becomes a signal, oscillation starts from L, and when the signal S30 becomes an L signal, the oscillation is stopped and fixed to L. Pulse generation circuit 4
7, when the signal S30 shown in FIG. 8H is input, a pulse signal of a predetermined fixed cycle is output while the signal S30 is H, and transmission is stopped while the signal S30 is L. . The output signal of the pulse generation circuit 47 is input to an inverter gate 45, which inverts the input signal and outputs an output signal S31 shown in FIG.
Input to D gate 46.

The AND gate 46 is supplied with A shown in FIG.
The output signal S29 of the ND gate 39 and the output signal S31 of the inverter gate 45 shown in FIG.
The D gate 46 becomes an H signal when both input signals are H,
A welding release processing signal S32 shown in (K) is output. The operation of the output signal S29 is the same as that of the device shown in FIG.

The welding release processing signal S32 is output from the output control circuit 5
And the output control circuit 5 outputs the welding release processing signal S32
Outputs an output signal S10 during the period of H
A predetermined voltage is supplied between 0 and the workpiece 11. At this time, the supply time (T6) can be determined by setting the mono multivibrator 32.

When the electrode wire 10 does not contact the workpiece 11 during the welding release command period (T6), FIG.
Is not output, the output signal of the monomultivibrator 33 remains L, and the output signal S25 of the monomultivibrator 17 also becomes L. This signal S25 is inverted by the inverter gate 36 to become an H signal. NAND gate 38. NAND gate 38
The H signal and the signal S28 shown in FIG. 8F are input, and a signal S26 which becomes L when both signals are H is output. The signal S26 is input to the reset terminal R of the RS flip-flop 40, and at the same time when the input signal S28 first rises to H, the RS flip-flop 40 is reset and the Q terminal becomes L, as shown in FIG. Output signal S29 shown
Becomes L. The signal S28 shown in FIG. 8 (F) and the H signal of the inverter gate 43 are input to the AND gate 44. When both the input signals are H, they are output as H signals and input to the pulse generation circuit 47. The pulse generating circuit 47 outputs a pulse signal having a constant period during a period when the input signal S30 is H,
The output signal S31 inverted by the inverter gate 45 and shown in FIG. The AND gate 46 is connected to the output signal S29 shown in FIG.
An output signal S31 shown in (M) is input, and when both input signals are H, a welding release processing signal S32 shown in FIG.

The relationship of H or L of each signal described in each of the above embodiments and the logic circuit to be used are not limited to those shown in each of the embodiments, and the same operations as those described in each of the embodiments. And the logical configuration is arbitrary.

[0056]

Since the present invention is as described above, it is not necessary to prepare a power source having a constant voltage characteristic for the welding release processing, and the welding can be reliably released.

[Brief description of the drawings]

FIG. 1 is a connection diagram showing an example of an apparatus for performing a welding method of the present invention.

FIG. 2 is a diagram showing changes in output current and voltage at the end of welding when the welding method of the present invention is performed by the apparatus shown in FIG. 1 over time.

FIG. 3 is a connection diagram showing another example of an apparatus for performing the welding method of the present invention.

FIG. 4 is a diagram showing changes in output current and voltage at the end of welding when the welding method of the present invention is carried out by the apparatus of FIG. 3 over time.

FIG. 5 is a connection diagram showing another example of an apparatus for performing the welding method of the present invention.

FIG. 6 is a diagram showing changes in output current and voltage at the end of welding when the welding method of the present invention is performed by the apparatus of FIG. 5 with time.

FIG. 7 is a connection diagram showing another example of an apparatus for performing the welding method of the present invention.

8 is a diagram showing changes in output current and voltage at the end of welding when the welding method of the present invention is performed by the apparatus of FIG. 7 with time.

FIG. 9 is a diagram showing changes in output current and voltage at the end of welding when a conventional welding method is performed with the passage of time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Torch switch 2 Output setting device 3 Driver circuit 4 Welding power supply 5 Output control circuit 6 Welding current detector 7 Welding voltage detector 8 Wire feed motor 9 Wire feed roll 10 Electrode wire 11 Workpiece 12 Mono multivibrator 13 Welding Release processing circuit 14 Mono multivibrator 15 Pulse generation circuit 16 AND gate 18 Weld detection circuit 19 Arc detection circuit 20 Short circuit detection circuit 21 AND gate 22 Weld release processing circuit 23 Mono multivibrator 24 AND gate 25 Inverter gate 26 RS flip-flop 27 mono multivibrator 28 mono multivibrator 29 monomultivibrator 30 inverter gate 31 AND gate 32 monomultivibrator 33 monomultivibrator 34 monomultivibrator Elevator 35 Mono-multi vibrator 36 Inverter gate 37 OR gate 38 NAND gate 39 AND gate 40 RS flip-flop 41 Weld release processing circuit 42 Weld release processing circuit 43 Inverter gate 44 AND gate 45 Inverter gate 46 AND gate 47 Pulse generating circuit 48 Inverter gate 49 OR gate Ib Welding current detection signal Vb Welding voltage detection signal S2a Welding current setting signal S2e Welding voltage setting signal

Claims (5)

[Claims] In a consumable electrode type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic, a predetermined end process is executed at the end of welding to send the consumable electrode. The power supply and the power supply from the welding power supply are stopped, and after a predetermined stop time (Ta), an output of a predetermined voltage is supplied from the welding power supply to the consumable electrode, and a predetermined supply time (Tb) is supplied. Thereafter, the output of the welding power supply is stopped, and after a predetermined stop time (Tc), the restart and stop of the output supply of the welding power supply are stopped for a predetermined time (Tc).
Consumable electrode arc welding method repeated during 2). 2. A consumable electrode type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic. The power supply and the power supply from the welding power supply are stopped, and after a predetermined stop time (Ta), an output of a predetermined voltage is supplied from the welding power supply to the consumable electrode, and the output voltage and the output from the welding power supply are supplied. The presence or absence of an arc is monitored based on the change with the current.
After a predetermined supply time (T4) from the occurrence of the arc, the output of the welding power source is stopped, and when no arc is detected, after the supply of the voltage to the consumable electrode is started, after a predetermined time (T3 + Td). A consumable electrode type arc welding method for stopping the output of the welding power source. 3. A consumable electrode-type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic. The power supply and the power supply from the welding power supply are stopped, and after a predetermined stop time (Ta), an output of a predetermined voltage is supplied from the welding power supply to the consumable electrode, and the output voltage and the output from the welding power supply are supplied. The presence or absence of an arc is monitored from the change with the current, and when the arc is not detected, the output of the welding power source is stopped after a predetermined time (T6) after the supply of the voltage to the consumable electrode is started,
When the occurrence of arc is detected, the output of the welding power source is stopped after a predetermined supply time (T4) from the detection of the arc occurrence, and the output of the welding power source is restarted after a predetermined stop time (Tc). A consumable electrode-type arc welding method in which detection of presence / absence of arc generation and operation of stopping the output of the welding power source after a predetermined supply time (T4) upon detection of arc generation are repeated for a predetermined time (T6). 4. In a consumable electrode type arc welding method in which power is supplied to a consumable electrode from a welding power source having a drooping characteristic or a constant current characteristic, a predetermined end process is executed at the end of welding to send the consumable electrode. The power supply and the power supply from the welding power supply are stopped, and after a predetermined stop time (Ta), an output of a predetermined voltage is supplied from the welding power supply to the consumable electrode, and the output voltage and the output from the welding power supply are supplied. The presence or absence of an arc is monitored based on the change with the current. When the arc is detected, the output of the welding power source is stopped after a predetermined supply time (T4) from the occurrence of the arc. After a predetermined time (Tb) from supplying an output of a predetermined voltage to the consumable electrode, the output of the welding power supply is stopped, and after a predetermined stop time (Tc), the output of the welding power supply is supplied. Re A consumable electrode type in which the output is stopped after a predetermined supply time (T4) after detecting the opening and occurrence of the arc, and the output is stopped for a predetermined time (T6) after the predetermined time (Tb) when no arc is generated. Arc welding method. 5. The consumable electrode type arc welding method according to claim 3, wherein the predetermined time (T6) is counted from the end of the predetermined stop time (Ta).