JPH11197829A - Welding wire feed condition control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed an appropriate welding wire to a groove part by automatically judging whether or not a wire feed amt. is appropriate. SOLUTION: When a judgment reference signal Vref is lower than a wire feed condition amplified signal A.Vs which is obtained by amplifying the wire feed condition detection signal Vs detected by a wire feed condition detector 8, a wire feed condition deviation signal ΔV is obtained from the difference between the signals A.Vs and Vrerf, a wire feed amt. signal Vout 1 is obtained from the difference between a wire feed set signal VWS and the wire feed condition deviation signal ΔV, a wire feed motor control signal Vout2 is obtained by multiplying a coefficient B to a value obtained from the difference between the wire feed signal quantity Vout1 and a wire feedback signal Vwf detected by wire speed detector 17 and a wire feed motor control signal Vout2 is provided to a motor 4 of a wire feeder 3 to control the rotational speed of the motor 4. Thus, as the rotating number of the wire motor is detected, an appropriate welding wire can be fed not only by checking the wire feed but also by automatically judging whether or not the wire feed is appropriate to an actual welding pool. The control following a change in a welding current etc., can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding wire feeding state control device.

[0002]

2. Description of the Related Art In MAG welding as well as TIG and MIG, it is necessary to feed an appropriate amount of welding wire to a groove portion of a work per unit time, but conventionally, an appropriate amount of welding wire is fed to a groove portion. There is no means for automatically judging whether or not the power is supplied, that is, whether or not the amount of welding is appropriate, and the welder looks at the molten pool of the welding wire formed on the groove and performs the operation.

In the case of automatic welding, various data relating to welding conditions obtained by the welding work of a skilled welder are input to a computer, and the welding of the skilled welder is faithfully reproduced by computer control.

[0004]

A welder needs intuition and experience to judge whether or not a proper amount of welding wire is supplied while looking at a welding pool.

[0005] Further, in automatic welding, it takes a great deal of time and a large amount of money to obtain data on welding conditions for a new work to be welded.

In view of the above circumstances, the present invention automatically determines whether or not an appropriate amount of wire is supplied to a groove per unit time, that is, whether or not a welding amount is appropriate, without depending on experience. It is another object of the present invention to provide a welding wire feeding state control device capable of controlling a wire feeding amount, that is, a welding amount, to be appropriate without obtaining welding data every time a workpiece to be welded becomes new. It was done.

[0007]

Background of the Invention When a welding wire is fed from a wire feeder through a wire conduit to an electrode portion, a wire feeding state detector such as a microphone or a vibrometer is installed outside the wire conduit. When the output voltage was measured, a graph of a waveform curve as shown in FIG. 2 was obtained. When the graph was analyzed, the following was clarified.

That is, in the case of a waveform A in which the output voltage is not so high and changes relatively regularly, the welding wire is fed in a good condition into the molten pool, but the output voltage is high and irregular. In such a case, the welding wire becomes excessively fed (including runaway), the tip of the welding wire pierces the work, and a load is applied to the welding wire. It turns out that the feeding condition is bad.

Further, when the wire conduit is actually touched during welding, if the welding wire is in a good feeding state, a slight rhythmic vibration (sound) is felt. In this case, the output voltage is reduced. If the feeding state of the welding wire is excessive, a rough and irregular vibration (sound) is felt, and in this case, the output voltage increases.

Therefore, when the output voltage obtained by detecting the sound or vibration of the welding wire moving in the wire conduit at the time of welding is lower than the predetermined value X, the feeding state of the welding wire is performed well. Thus, it was found that when the output voltage was higher than the predetermined value X, the feeding of the welding wire was excessive, and it could be determined that the feeding of the welding wire was not performed well.

The present invention has been made based on the results of such experiments.

In FIG. 2, C shows the waveform of the output voltage at the start of wire feeding. When detecting the feeding state of the welding wire, the output voltage at the start of wire feeding is ignored.

[0013]

According to the present invention, there is provided a wire feed state detector for detecting a sound and a vibration generated from a welding wire fed from a wire feeder to an electrode, and a wire feed state detector. A signal amplifier 9 for multiplying the wire feed state detection signal Vs from the feed state detector 8 by a coefficient A to obtain a wire feed state amplified signal A · Vs; and a predetermined reference signal Vref and a signal from the signal amplifier 9. By comparing the amplified signal A · Vs with the wire feeding state, if the judgment reference signal Vref <the amplified signal A · Vs in the wire feeding state, the difference between the judgment reference signal Vref and the amplified signal A · Vs in the wire feeding state is calculated. Wire feed state determiner 11 for obtaining wire feed state deviation signal ΔV
The wire feed amount setting signal Vws set in advance and the wire feed state deviation signal ΔV from the wire feed state determination unit 11
The wire feed rate calculating circuit 12 for obtaining the wire feed rate signal V _out1 taking the difference between the wire of the wire speed from the wire feed rate signal V _out1 and the wire feeder 3 from the wire feed amount calculating circuit 12 seeking wire feed motor control signal V _out2 by multiplying the coefficient B to the difference with a difference feedback signal Vwf, is that a wire feed motor control circuit 18 to be supplied to the motor 4 of the wire feeder 3.

Therefore, in the present invention, the wire feed motor control signal V _out2 is automatically obtained based on the detected wire feed state detection signal Vs, and the wire feed motor control signal V out
_Since the rotation speed of the motor 4 of the wire feeder 3 is controlled by _out2, it is automatically determined whether or not an appropriate amount of the welding wire 5 is fed to the groove, that is, whether or not the welding amount is appropriate. In addition, since the control is performed so that the wire feeding amount, that is, the welding amount, is appropriate, it is possible to perform good welding.

In the present invention, when the wire feeding state deviation signal .DELTA.V from the wire feeding state judging device 11 continues for a predetermined time, an alarm is prepared and a wire stop and welding stop signal Vst is output. When the feeding state deviation signal monitoring device 14 is provided, the reliability of the device is improved.

[0016]

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

FIG. 1 shows an example of an embodiment of the present invention applied to a TIG welding apparatus. In the figure, reference numeral 1 denotes a welding torch having electrodes 2 and 3 denotes a wire feeder which can be driven by a motor 4. In addition, the welding wire 5 sent from the wire feeder 3 passes through the inside of the wire conduit 6 and is fed to the electrode 2 of the welding torch 1.

Reference numeral 7 denotes an external sound blocking cone provided at an intermediate portion of the wire conduit 6 in the longitudinal direction, and reference numeral 8 denotes an external sound blocking cone 7 which detects a sound other than a sound emitted from the welding wire 5.
A wire feeding state detector 9 such as a microphone vibrometer inserted in the inside, a signal amplifier 9 capable of receiving the wire feeding state detection signal Vs detected and transmitted by the wire feeding state detector 8 In the signal amplifier 9, the wire feed state detection signal Vs can be multiplied by a coefficient A to obtain a controllable wire feed state amplified signal A · Vs.

Reference numeral 10 denotes a judgment reference voltage (corresponding to X in FIG. 2) serving as a reference for judging the quality of the feeding state of the welding wire 5.
Is a determination criterion setting device that can be set as a criterion signal Vref.

Reference numeral 11 denotes a wire feed state judging unit. In the wire feed state judging unit 11, the wire feed state amplified signal A · Vs from the signal amplifier 9 and the judgment reference signal Vref from the judgment standard setting unit 10 are used. And if Vref <A · Vs, the wire feeding state deviation signal ΔV (= A
Vs-Vref) can be obtained.

The reference numeral 12 subtracts the wire feeding state deviation signal ΔV from the wire feeding state judging device 11 and the wire feeding amount setting signal Vws from the wire feeding amount setting device 13 to obtain a wire feeding amount signal V _out1 ( = Vws-ΔV).

Reference numeral 14 measures the time during which the wire feeding state deviation signal .DELTA.V is output from the wire feeding state judging device 11, and prepares to issue an alarm when a predetermined time has elapsed, and stops the wire stop and the welding stop. A wire feeding state deviation signal monitoring device for outputting a signal Vst, which is reset when the wire feeding state deviation signal ΔV is no longer provided.

Reference numeral 15 denotes a wire feeding state deviation signal monitoring device 1
4 is a sequence control circuit for performing sequence control of the entire welding apparatus based on the signal Vst of the wire stop and the welding stop from 4

Reference numeral 16 denotes a relay contact circuit. Reference numeral 17 denotes a wire speed detector such as a tachometer that detects the rotation speed of the motor 4 of the wire feeder 3 and outputs the detected speed as a wire feedback signal Vwf. The wire feedback signal Vwf can be supplied to the wire feed motor control circuit 18 through the relay contact circuit 16.

The wire feed motor control circuit 18 calculates the difference between the wire feed amount signal V _out1 from the wire feed amount calculation circuit 12 and the wire feedback signal Vwf detected by the wire speed detector 17, and calculates the difference. multiplied by the coefficient B wire feed motor control signal _{V ou t2 (= B · (} V out1 -Vw
f)) can be obtained, and the obtained wire feed motor control signal V _out2 can be given to the motor 4 via the relay contact circuit 16.

The sequence control circuit 15 can supply a signal Vst for stopping wire feeding and welding to the motor 4 and other welding equipment via the relay contact circuit 16.

Next, the operation of the present invention will be described.

At the time of welding, power is supplied to the electrode 2 of the welding torch 1 and the wire feeder 3 is driven to feed the welding wire 5 to the electrode 2 through the wire conduit 6 to perform welding.

The feeding state of the welding wire 5 fed from the wire feeder 3 is controlled as follows.

That is, in the wire feeding state detector 8,
A sound or vibration generated when the welding wire 5 is fed is detected and given to the signal amplifier 9 as a wire feeding state detection signal Vs. The signal amplifier 9 multiplies the wire feeding state detection signal Vs by a coefficient A. Then, a wire feed state amplified signal A · Vs of a level that can be processed in a subsequent process is obtained, and the obtained wire feed state amplified signal A · Vs is supplied to the wire feed state determination unit 11.

From the criterion setting device 10, the welding wire 5
Criterion signal V serving as a criterion for determining the quality of the feeding state
ref is given to the wire feed state determiner 11, and the wire feed state determiner 11 compares the determination reference signal Vref with the amplified wire feed state signal A · Vs.

Therefore, when Vref ≧ A · Vs, the feeding of the welding wire 5 is performed stably, and therefore, no signal is output from the wire feeding state judging device 11. Since the wire feed motor control signal _Vout2 does not change, the rotation speed of the motor 4 does not change.

On the other hand, if Vref <A · Vs, the welding wire 5 is excessively fed, so that the wire feeding state judging device 11 uses the amplified wire feeding state signal A · Vs to determine the judgment reference signal Vref. Is subtracted, and the wire feeding state deviation signal Δ
V is obtained, and the obtained wire feeding state deviation signal ΔV
Is supplied to the wire feed amount calculation circuit 12 and the wire feed state deviation signal monitoring device 14.

From the wire feed amount setting unit 13, the feed amount of the welding wire 5 to be fed to the groove portion per unit time is sent to the wire feed amount calculating circuit 12 as a wire feed amount setting signal Vws. The wire feed amount calculation circuit 12 receives the wire feed state deviation signal ΔV from the wire feed amount setting signal Vws.
Is subtracted to obtain the wire feed amount signal V _out1 , and the obtained wire feed amount signal V _out1 is provided to the wire feed motor control circuit 18.

On the other hand, the rotation speed of the motor 4 detected by the wire speed detector 17 is given as a wire feedback signal Vwf to a wire feed motor control circuit 18 via a relay contact circuit 16, and the wire feed motor control circuit 18 , from the wire feed rate signal V _out1 wire feedback signal Vwf by the coefficient B is multiplied to the signal obtained by subtracting the wire feed motor control signal V _out2 is obtained, the wire obtained feed motor control signal V _out2 is the relay contact circuit 1
6, and is given to the motor 4 of the wire feeder 3.

For this reason, the rotation speed of the motor 4 is controlled to an appropriate speed such that the welding wire 5 is not excessively fed to the groove.

As described above, in the present embodiment, the intuition and experience of the operator determine whether or not an appropriate amount of wire is fed to the groove per unit time, that is, whether or not the welding amount is appropriate. It is possible to automatically determine without depending on
As a result, control is performed so that the wire feeding amount, that is, the welding amount is appropriate, and good welding can be performed.

When the wire feeding state deviation signal .DELTA.V is supplied to the wire feeding state deviation signal monitoring device 14, the time during which the wire feeding state deviation signal .DELTA.V is continuously input is monitored. Is prepared for the alarm, and the wire stop and welding stop signal Vst is output from the wire feed state deviation signal monitoring device 14, and the output wire stop and welding stop signal Vst is output to the sequence control circuit 1
5 to the motor 4 of the wire feeder 3 via the relay contact circuit 16 and to other welding equipment.

For this reason, the motor 4 is stopped, the supply of the welding wire 5 is stopped, and the welding of other welding equipment is also stopped by stopping the motor and the like.

Therefore, the state of excessive feeding of the welding wire 5 does not continue so much, and the reliability of the apparatus is improved.

The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0042]

According to the welding wire feeding state control device of the present invention, in the case of claim 1, it is determined whether or not an appropriate amount of wire is fed to the groove, that is, whether or not the welding amount is appropriate. Can be automatically determined, and as a result, control is performed so that the wire feeding amount, that is, the welding amount, is appropriate. Therefore, fusion failure due to excessive wire feeding does not occur, and therefore, there is no welding defect. Welding can be performed,
In the case of claim 2, various excellent effects such as improvement of the reliability of the device can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is a graph showing an example of a change over time of an output voltage of a wire feeding state detector.

[Explanation of symbols]

2 Electrode 3 Wire Feeder 5 Welding Wire 8 Wire Feeding State Detector 9 Signal Amplifier 11 Wire Feeding State Judgment Unit 12 Wire Feeding Amount Operation Circuit 14 Wire Feeding State Deviation Signal Monitoring Device 18 Wire Feeding Motor Control Circuit Vs Wire feeding state detection signal A coefficient A · Vs wire feeding state amplified signal Vref criterion signal ΔV wire feeding state error signal Vws wire feed rate setting signal V _out1 wire feed rate signal Vwt wire feedback signal B factor V _out2 wire Feed motor control signal Vst Wire stop and welding stop signal

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takashi Miyazaki 5292 Aioi, Aioi-shi, Hyogo Ishikawajima-Harima Heavy Industries Co., Ltd. Aioi factory

Claims (2)

[Claims] 1. A wire feeding state detector (8) for detecting a remarkable vibration generated from a welding wire (5) fed from a wire feeder (3) to an electrode (2).
A signal amplifier (9) for multiplying a wire feeding state detection signal (Vs) from the wire feeding state detector (8) by a coefficient (A) to obtain a wire feeding state amplified signal (A · Vs); The determined reference signal (Vref) and the amplified wire feed state signal (A · Vs) from the signal amplifier (9) are compared to determine the reference signal (Vref) <the amplified wire feed state signal (A).
(Vs), a wire feeding state determiner (11) that obtains a wire feeding state deviation signal (ΔV) by taking a difference between the determination reference signal (Vref) and the wire feeding state amplified signal (A · Vs).
And a difference between a preset wire feed amount setting signal (Vws) and a wire feed state deviation signal (ΔV) from the wire feed state determiner (11), and calculates a wire feed amount signal (V _out1 ).
And a wire feed amount signal (V _out1 ) from the wire feed amount calculation circuit (12).
And a wire feedback signal (Vwf) relating to the wire speed from the wire feeder (3) and multiplying the difference by a coefficient (B) to control the wire feed motor control signal ( _Vout2 ).
And a wire feed motor control circuit (18) for determining the value and supplying it to the motor (4) of the wire feeder (3). 2. When the wire feeding state deviation signal (.DELTA.V) from the wire feeding state judging device (11) continues for a predetermined time, an alarm is prepared and an output signal (Vst) of wire stop and welding stop is output. The welding wire feeding state control device according to claim 1, further comprising a wire feeding state deviation signal monitoring device (14).