KR100253659B1 - Control apparatus of welding machine - Google Patents

Abstract

PURPOSE: A control system of a semi-automatic welder is provided to remotely control the welder from a wire feeder with only signal lines. CONSTITUTION: A control system contains an A/D converting unit(A/D) to convert plural control signals to digital signals; a transmission control unit(CPU1) in a wire feeder to transmit the digital signals as a serial signal through a time sharing; a receiving control unit(CPU2) to generate a parallel signal with the serial signal; D/A converting units(DA1-DA3) to convert the reproducing signal from the receiving control unit; and amplifying units(AMP1,AMP2) in a welder to reproduced the control signal by amplifying the analog signals from the D/A converting units. Thereby, a control cable is stored in a gas hose by reducing signal lines.

Description

Semi-automatic Welding Machine

The present invention relates to a control system of a semi-automatic welding machine, and more particularly to a control device suitable for use in the semi-automatic welding of the protective gas metal arc welding.

Shield gas metal arc welding (shield gas metal arc welding) is a welding method to form a welding atmosphere with a protective gas to improve the welding efficiency and quality, and to enable the welding of the material impossible by the coated arc welding. Protection is also (Tungsten Inert Gas) TIG gas metal arc welding the welding processes, such as rain (非) yonggeuk (溶極) expression welding process and, MIG (Metal Inert Gas) or carbon dioxide (Co ₂₎ or MAG (Metal Active Gas) welding techniques, such as There is a melt welding method using a consumable electrode. In molten protective gas metal arc welding, a metal wire is used as a consumable electrode to continuously supply a welding rod. In this case, a wire feeding device is a wire feeding device.

FIG. 1 shows a general configuration of a semi-automatic carbon dioxide gas welding machine. A molten protective gas metal arc welding machine such as a MIG welding machine has a configuration substantially similar thereto.

In FIG. 1, the welding machine V connected to the power source AC supplies a welding current, and carbon dioxide gas (inert gas in the case of MIG, mixed gas in the case of MAG) is supplied from a gas bomb B. A wire feeder (F) is used for continuous feeding of the wire (W). The wire (W) is wound on a spool (S) installed in the wire feeder (F) and the wire feeder (F). Is supplied to the torch (T).

The wire feeder (F) is configured in a portable size and weight for the convenience of welding work, and between the welding machine (V) and the gas cylinder (B), a power cable (P), a control cable (C) and a gas hose, which are usually several tens of meters in length, Connected to (G).

The welding current supplied to the power cable P is connected to the wire W fed from the wire feeder F, and the atmosphere gas such as carbon dioxide gas supplied to the gas hose G is connected to the wire W from the torch T. Is sprayed around). Meanwhile, the control cable C transmits a control signal for controlling the welding machine V from the wire feeder F or a separate controller.

However, in the conventional semi-automatic welding machine, since the power cable P, the control cable C, and the gas hose G are separately configured and extended several tens of meters, there are various problems as follows.

In other words, since three cables and hoses (P, C, G) are extended from the welding machine (V) to the wire feeder (F) of the work site, the volume and weight thereof are very large and large, such as ship construction or steel structure. In the case of constructing the structure, a plurality of welding operations are performed at the same time, so that a plurality of cables and hoses (P, C, G), each of three strands, are complicatedly extended, which may cause safety accidents. To prevent this, it is common to bind the three cables and hoses (P, C, G) with cable ties or harnesses, but in this case, there is a very troublesome problem when installing or moving a welder.

Meanwhile, these three cables and hoses P, C, and G are connected to the wire feeder F as shown in FIG. That is, the power cable P and the control cable C are connected through a coupler K1 and K2, and the gas hose G is connected to the wire feeder F through a nipple N. Is connected to the torch (T).

Since the cables and hoses (P, C, G) are connected independently of each other, it is very likely that these couplers (K1, K2) or nipples (N) are separated, and three strands independent of each other in a long path of several tens of meters are used. If any of the cables and hoses (P, C, G) are damaged or leaked, it is very difficult to detect them. For example, even when the gas hose G is separated from the nipple N or damaged on the extension path, the gas is stopped or the flow is insufficient. Even if the cable C is disconnected and the welding current is inappropriate, a problem may occur in which the welding proceeds as it is if the power cable P is connected.

Accordingly, various proposals have been made to integrate the power cable (P), the control cable (C), and the gas hose (G) to enable handling and coupling.

One of them is the structure shown in Fig. 3, which is a "welding cable" disclosed in September 5, 1987, Utility Model Publication No. 87-2569.

In FIG. 3, the cable assembly 11 has a gas hose G arranged at the center thereof and a power cable P made of conductive wires 13 wrapped around the outside thereof, and again an outer insulator on the outside thereof. Signal lines 12 insulated by (15) form a control cable (C) and are covered with an insulating coating (14). Here, a spring (not shown) is inserted into the liner between the gas hose G and the conductive line 13.

The cable assembly 11 has a very compact configuration, but has a fundamental problem and is not widely used.

That is, since the protective gas welding such as CO ₂ welding is basically arc welding, a large power is required, and a high voltage or high current power must be supplied to the power cable (P). For example, the power supply voltage used for general CO ₂ melting point is about 18 to 52V, but the current becomes a very large large current of 200 to 500A.

Therefore, a strong magnetic field is formed around the power cable P. In the configuration of FIG. 3, the signal lines 12 of the control cable C are spaced apart from only the insulator 15 of a thin layer so that the conductive lines of the power cable P 13), there is a problem that large noise is mixed in the signal line 12 by induction current or the like, so that proper welding apparatus is not controlled, and damage to the welding apparatus is caused by a large ripple current.

On the other hand, shown in Figure 4 is a "welding cable assembly" filed in 1995 Utility Model Registration No. 9333 by the applicant of the third party in 1995.

In Fig. 4, the coaxially arranged gas hoses G and the control cables C are arranged in parallel with the power cables P by an eight-shaped insulating sheath 14 (16 is a covering material). ).

In this configuration, since the signal lines 12 of the control cable C do not surround the conductive lines 13 of the power cable P and are sufficiently separated from each other, noise is mixed in the signal cable C or a ripple current is generated. The problem that arises can be prevented efficiently.

However, such a pre-applied cable assembly 11 has a rather cumbersome problem compared to the configuration of FIG.

However, such a configuration problem of the cable assembly 11 is because the control cable (C) is composed of too many signal lines (12). This signal line 12 is generally composed of 9 to 12, as the control cable (C) of the cable assembly 11 is composed of a plurality of signal lines 12 in this way, they occupy a considerable cross-sectional area, so that the cable assembly The volume and weight of (11) increase, which causes various problems in the installation and use of the welding apparatus.

Although the terms signal line 12 and control cable C are used herein, these are actually only bundles of wires as shown in FIG.

FIG. 5 illustrates a control cable C composed of nine signal lines 12 (I1 to I9) for transmitting signals I1 to I9 (the same reference numerals as the signal lines below). ) Is for controlling the welding machine (V in FIG. 1) several tens of meters away from the wire feeder (F in FIG. 1) where the worker is working.

In the example illustrated in FIG. 5, I1 is applied 9-31V (reference 24V) to the power supply line of the feeding motor M for supplying the wire W, I2 is the common ground line OV, and I3 is inching In case of (inching), 15V is applied to the switch line for idling the feeding motor (M), I4 is applied to the switch line of the torch (T), and I5 cuts off the gas supply from the gas cylinder (B). 24V is also applied to the control line of the solenoid valve SOL. The remaining signal lines I6 to I9 are signal lines for selecting craters or controlling welding voltage or speed of the feeding motor M, respectively, and different potentials are applied as necessary.

As such, the signal lines 12 (I1 to I9) of the conventional control cable C do not actually transmit data, but merely extend the wires of the on / off switch by several tens of mm.

Although the idea of reducing the signal lines 12 (I1 to I9) of the conventional control cable C to reduce the cross section of the cable assembly 11 by digitizing such signals I1 to I9 is not conventionally conceived, Essentially, the usage potential of each signal line 12; The digital control system has not been proposed or put to practical use in this field because it is considered impossible to transmit the

In view of such conventional problems, an object of the present invention is to provide a system capable of remotely controlling a welder from a wire feeder using only one or several signal lines.

1 is a block diagram showing a general configuration of a semi-automatic carbon dioxide gas welding machine.

2 is a main perspective view showing a connection portion of a cable and a hose in a conventional connection method.

3 is a cross-sectional view showing the configuration of a conventional welding cable assembly.

Figure 4 is a cross-sectional view showing the configuration of the present application welding cable assembly of the present application.

5 is a block diagram showing a conventional control system.

6 is a block diagram showing a control system of the present invention.

7 is a waveform diagram showing a preferred form of a control signal in the present invention.

8 is a waveform diagram showing a more preferred form of the control signal of the present invention.

9A and 9B are cross-sectional views each showing a configuration of a welded cable assembly which can be achieved by the present invention.

* Explanation of symbols for main parts of the drawings

V: welder F: wire feeder

I1 ~ I9: Control Signal I10: Serial Signal

CPU1: Transmission control unit CPU2: Reception control unit

A / D: A / D Converter D / A1 ~ D / A3: D / A Converter

P / S: Parallel to Serial Conversion S / P: Serial to Parallel Conversion

AMP1, AMP2: Amplifier

The control device according to the present invention for achieving the above object is

The wire feeder is provided with an A / D conversion unit for A / D conversion of a plurality of control signals and a transmission control unit for time-divisionally dividing the A / D converted digital signal into a serial signal.

A reception control unit for reproducing a serial signal applied along the signal line from the transmission control unit as a parallel signal, a D / A conversion unit for D / A converting a reproduction signal from the reception control unit, and from this D / A conversion unit It characterized in that the welding unit is provided with an amplifier for amplifying the analog (analog) signal to the required potential.

The configuration of the present invention is to reproduce the parallel analog signal transmitted from the wire feeder as it is in the welding machine, the existing wire feeder and the construction of the existing welder itself by simply adding the control device of the present invention to the welder. There is no need to change or add expensive control elements such as relays or solenoids.

In addition, it is possible to greatly reduce the number of signal lines of the control cable from one to one, which makes it very simple to configure the cross section of the cable assembly.

EXAMPLE

Such specific features and advantages of the present invention will become more apparent from the following description of the preferred embodiments with reference to the accompanying drawings.

In FIG. 6, the control device according to the present invention is characterized by the signal line 2 (preferably) of the control cable C of the sending part provided in the wire feeder F and the receiving part provided in the welding machine V. It is connected and configured.

The transmitting part and the receiving part are preferably configured on a card-shaped circuit board, respectively, and are coupled to the wire feeder F and the welding machine V shown in FIG. 1, respectively. F) and welder V require no change or addition of the control element as described above.

To this end, the control device of the present invention should reproduce the control signals I1 to I6 at the front end of the transmitting part of the wire feeder F as it is at the rear end of the receiving part of the welding machine V. Hereinafter, the configuration thereof will be described.

First, referring to the transmitter of the wire feeder F, control signals I1 to I6, which are analog signals in nine parallel states, are converted into digital signals I1 ′ to I9 ′ through the A / D converter A / D. . Here, the control signals I1 to I6 have respective potentials of 9V to 31V, 15V or 24V, or the potentials of the digital signals I1 'to I9' outputted to the A / D converter A / D are digital. It has a value of 0V or 5V, the output potential of the IC.

The digital signals I1 'to I9' are inputted to the transmission control unit CPU1 and converted into serial signals. Preferably, the transmission control unit CPU1 has a latch unit LC1 and a parallel-to-parallel conversion unit P. / S).

The latch unit LC1 alternates the passage of the digital signals I1 'to I9' from the A / D conversion unit A / D in accordance with a predetermined timing in accordance with the internal clock of the transmission control unit CPU1. The time division is achieved by latching.

The time-divided digital signals I1 'to I9' are converted into a series of serial signals I10 through the parallel-to-serial conversion unit P / S, and are transmitted to the signal line 2.

Here, the digital signals I1 'to I9' time-divided by the digital switching in the latch unit LC1 may be synthesized as they are in the parallel-to-serial conversion unit P / S to form a serial signal I10 as shown in FIG. have.

In FIG. 7, the serial signal I10 is sequentially repeated from the first signal to the ninth signal in accordance with the time division at the latch portion LC1. Preferably, this division is applied to the front end of each welder V. A start pulse for recognizing the receiver is added, followed by the signal pulses corresponding to the respective control signals I1 to I6.

The magnitude of the control signals I1 to I6 may be represented as the number of signal pulses (PCM method) or the width of the signal pulses (PWM method) as shown.

In FIG. 7, it is assumed that all control signals I1 to I9 are serially transmitted by D / A conversion. However, when the required power becomes large, even if the receiver regenerates and amplifies the A / D to obtain sufficient power for control. Difficult cases may arise.

Accordingly, in the embodiment shown in FIG. 8, the potential of one of the signals I1 to I9, for example, the power supply line I1 of the power supply motor M is referred to as the reference potential, and the serial signal of FIG. I10) is added to this reference potential as a signal potential to transmit.

The transmission method of FIG. 8 has the advantage of reproducing high power by the reference potential by transmitting a signal potential of low potential (0 or 5V) by using a high potential (9 to 31 V) as the reference potential as a carrier wave. There is this.

Back to FIG. 6, filter units FT1 and FT2 are provided at the front and rear ends of the signal line 2, respectively, to prevent noise from the power cable P (not shown in FIG. 6) adjacent to the signal line 2. Shuts off and prevents reverse current flow.

The main source of noise for the control cable (C) is the power cable (P), because the large power passes through the power cable (P). At this time, the period of the noise or ripple current is mainly an integer multiple of the period of the current (for example, 60Hz) passing through the power cable (P).

Accordingly, the higher the transmission frequency of the serial signal I10, that is, the sampling frequency for A / D conversion of the control signals I1 to I9, to a higher frequency, the more accurate transmission of the control signals I1 to I9 becomes possible. It is also advantageous for regeneration.

Preferably, the transmission frequency of the serial signal I10 is 1000 Hz or more, and more preferably 9000 Hz or more.

Receiving control unit (CPU2) to the reception unit of the welding machine (V) side by converting the serial signal (I10) time-divisionally transmitted through the signal line (2) to a plurality of control signals (I1 "to I9" in parallel again) ) Is provided.

The reception control unit CPU2 is a serial / parallel conversion unit S / P for serially and serially converting signal pulses in synchronization with the start pulse of the serial signal I10 and a latch for latching and converting the intermittent signals converted into a continuous signal. The part LC2 is provided.

The control signals I1 "to I9" reproduced by the reception control unit CPU2 are parallel digital signals, and are provided with a D / A converter (D / A1 to D / A3) to reproduce them as analog signals. do.

However, since the driving potential of ICs used for digital control is 0 to 5 V, the control signals reproduced by the D / A converters D / A1 to D / A9 are the same as those of the first control signals I1 to I9. The highest potential is 5V.

Accordingly, the amplifiers AMP1 and AMP2 are provided at the rear of the D / A converters D / A1 to D / A3 to reproduce the original control signals I1 to I9 by amplifying the control signal to the required potential. I will do it.

In this case, the control signals I1 to I9 are not intended to be used as a single potential, but 9-31V (power supply of the supply motor M), 15V (inching lamp) or 24V (solenoid valve (SOL) control lamp, etc.). Depending on the various potentials.

Accordingly, the amplifiers AMP1 and AMP2 are also divided into a plurality of amplifiers AMP1 and AMP2 having different amplification potentials according to the use potentials of the control signals I1 to I9, and the D / A converters D / A A1 to D / A3) are also preferably separated by the amplification units AMP1 and AMP2.

As described above, according to the present invention, the control signals I1 to I9 at the front end of the sending part of the wire feeder F can be reproduced as it is at the rear end of the receiving part of the welding machine V, so that the sending part and the receiving part are each of a card type circuit board. In this configuration, it is possible to apply the control device of the present invention to the conventional wire feeder (F) and the welding machine (V) without changing or adding other mechanical configuration.

On the other hand, the greatest effect of the application of the present invention is that it is possible to greatly reduce the number of signal lines of the power cable of the cable assembly from several to one, accordingly the cable assembly as shown in Figure 9a and b The configuration of can be adopted. These are those disclosed as "welded cable assemblies" (utility model registration application number later revised), each filed on the same day.

First, in FIG. 9A, the gas assembly G is arranged in a power cable P, which is composed of a conductive cable 3 arranged in an annular manner in the insulation coating 4. According to the present invention, since the number of signal lines 2 of the control cable C is reduced to three and in the illustrated embodiment, the control cable C can be arranged in the gas hose G (5 is the signal line 2 Insulation).

According to this configuration, since the control cable (C) does not occupy a separate area, the cross section of the cable assembly (1) is greatly reduced, and the magnetic fields are canceled with each other in the power cable (P) that passes through high power to form a large magnetic field. Since the control cable C is arranged inside, there is no fear of noise mixing due to the magnetic field.

Meanwhile, in FIG. 9B, the control cable C is composed of one signal line 2. Accordingly, the signal line 2 may be composed of one spiral without covering an insulator (5 of FIG. 9A). The configuration becomes simpler.

According to the present invention as described above, the configuration of the cable assembly is extremely simple, the handling and use is easy and accurate control, as well as a control device that can be used in addition to the existing welding apparatus is provided.

Claims (9)

A control apparatus for a semi-automatic welding machine which sends a plurality of control signals from a wire feeder to a welder through a control cable to control a welding state, comprising: an A / D converter for converting the plurality of control signals to A / D and A / D; A transmission controller for time-dividing the converted digital signal and outputting the serial signal as a serial signal; and a reception controller for reproducing the serial signal applied from the transmission controller along the control cable as a parallel signal, from the reception controller. And a D / A conversion unit for D / A conversion of the reproduction signal of the signal and an amplification unit for reproducing the control signal by amplifying the analog signal from the D / A conversion unit to the required potential. Control device of welding machine. The apparatus of claim 1, wherein the A / D conversion unit and the transmission control unit, the reception control unit, the D / A conversion unit, and the amplification unit are respectively formed on a circuit board in the form of a card, and are provided in the wire feeder and the welding machine, respectively. Control device of semi-automatic welding machine. 2. The apparatus of claim 1, wherein the transmission control unit comprises a latch unit for latching the A / D converted digital signal at a timing, and a parallel-serial conversion unit for parallel-converting the signal latched by the latch unit to the serial signal. Semi-automatic welding machine control device The apparatus of claim 1, wherein the reception control unit comprises a series-parallel conversion unit for serial-to-parallel conversion of the serial signal, and a latch unit for latching the signals converted therefrom into a continuous signal. . The apparatus of claim 1, wherein the amplifying unit is divided into a plurality of components according to the use potential of the control signal. 6. The control apparatus for a semi-automatic welding machine according to any one of claims 1 to 5, wherein the D / A conversion unit is divided into a plurality of units according to the amplifying unit. The apparatus of claim 1, wherein the serial signal is transmitted in a form in which a signal potential is added using any one of the control signals as a reference potential. The apparatus of claim 1, wherein a transmission frequency of the serial signal is 1000 Hz or more. The control apparatus for a semi-automatic welding machine according to claim 1, wherein one or several signal lines of the control cable are configured.

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