KR19990065473A - Semi-automatic welding machine control system - Google Patents

Abstract

The present invention relates to a control system suitable for use in a semi-automatic welder for protective gas metal arc welding.

According to the present invention, an A / D conversion unit for A / D conversion of a plurality of control signals and a transmission control unit for time-dividing A / D converted digital signals and outputting them as serial signals are provided in the welding machine, and signal lines are provided from the transmission control unit. A reception control unit for reproducing the serial signal applied along with the parallel signal as a parallel signal, a D / A conversion unit for D / A converting the reproduction signal from the reception control unit, and an analog from this D / A conversion unit (analog) The amplification unit amplifies the signal to the required potential in the wire feeder to transmit the control signals to the serial signal from the welding machine, and reproduces the parallel signal in the wire feeder to reproduce the same control signal. Accordingly, by reducing the number of signal lines to one to several, the control cable can be accommodated in the gas hose, it is possible to apply to the existing welding device in the card type configuration.

Description

Semi-automatic welding machine control system

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

In general, shield gas metal arc welding is a welding method that forms a welding atmosphere with a protective gas to improve welding efficiency and quality, and enables welding of materials that are impossible by covering 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 achieve continuous supply of a welding rod, and it is well known as a wire feeding device to supply a wire.

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 supply of the wire (W), the wire (W) is wound on the spool (S) installed in the wire feeder (F) wire feeder ( F) is supplied to the torch T.

The wire feeder (F) is composed of 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 (PC), a control cable (CC) and a gas hose, which are usually several tens of meters in length, are provided. (GH).

The welding current supplied to the power cable PC is connected to the wire W fed from the wire feeder F. Atmospheric gas such as carbon dioxide gas supplied to the gas hose GH is connected to the wire (T) in the torch T. Is sprayed around W). Meanwhile, the control cable CC transmits a control signal for controlling the welding machine V from the wire feeder F or a separate controller.

By the way, in the conventional semi-automatic welding machine configuration, the power cable (PC), the control cable (CC), and the gas hose (GH) are separately configured to extend several tens of meters, there are various problems as follows.

In other words, the three cables and hoses (PC) (CC) (GH) extend from the welding machine (V) to the wire feeder (F) of the shop floor, and the volume and weight thereof are very large. In the case of building a large structure like this, since a number of welding operations are performed at the same time, a plurality of cables and hoses (PC) (CC) (GH), each of three strands, are complicatedly extended, which may cause a safety accident. . To prevent this, it is common to bind three cables and a PC (CC) (GH) with a cable tie or harness, but in this case, it is very troublesome to install or move the welder. have.

Meanwhile, these three cables and hoses PC (CC) GH are connected to the wire feeder F as shown in FIG. 2. That is, the power cable PC and the control cable CC are connected through the couplers K1 and K2, and the gas hose GH is connected to the wire feeder F through the nipple N. It is connected to L) and is connected to the torch T.

In this way, since the cable and the hose (PC) (CC) (GH) are independently connected to each other, it is very likely that the coupler (K1) (K2) or the nipple (N) is separated and is independent of each other in a long path of several tens of meters. Any damage or leakage of any of the three cables and hoses (CC) (GH) is very difficult to detect. For example, even when the gas hose GH is separated from the nipple N or damage occurs on the extension path, the gas is supplied or the flow rate is insufficient. Even if the control cable (CC) is separated and the welding current is inappropriate, the problem is that the welding proceeds as it is if the power cable (PC) is connected.

Accordingly, various proposals have been made to integrate the power cable (PC), control cable (CC), and gas hose (GH) to allow for 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 1 has a gas hose GH arranged in the center thereof, and a power cable PC made of conductive lines 3 wrapped around the outside thereof, and again an outer insulator on the outside thereof. Signal lines 2 insulated by (5) form a control cable (CC) and are covered with an insulating coating (4). Here, a spring (not shown) is inserted into the liner between the gas hose GH and the conductive line 3.

As such, the cable assembly 1 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 (PC). For example, the power supply voltage used for general CO ₂ welding is about 18V to 52V, but the current becomes a very large large current of 200A to 500A.

Therefore, a strong magnetic field is formed around the power cable PC. In the configuration of FIG. 3, the signal lines 2 of the control cable CC are spaced apart from only a thin layer of insulator 5 so that the conductive lines of the power cable PC may be separated. Since the signal line 2 is adjacent to 3), a large noise is mixed into the signal line 2 due to an induction current, so that proper welding apparatus cannot be 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. 5. 3rd utility model registration application No. 95-9333.

In Fig. 4, the gas hoses GH and the control cables CC which are coaxially arranged are arranged in parallel with the power cables PC by an 8-shaped insulating coating 4 (6 is a covering material).

In this configuration, since the signal lines 2 of the control cable CC do not surround the conductive lines 3 of the power cable PC and are sufficiently separated from each other, the control cable CC control noise is mixed or ripple current is increased. The problem that arises can be prevented efficiently.

However, since the cross-section of the first application cable assembly (1) is not circular but 8-shaped, manufacturing and handling caused a somewhat cumbersome problem compared to the configuration of FIG.

And the configuration problem of the cable assembly (1) as described above is because the control cable (CC) is composed of too many signal lines (2). This signal line (2) is generally composed of 9 to 12, as the control cable (CC) of the cable assembly 1 is composed of a plurality of signal lines (2) in this way they occupy a considerable cross-sectional area, so that the cable assembly The volume and weight of (1) increase, which causes various problems in the installation and use of the welding apparatus.

Although the terms signal line 2 and control cable CC are used here, these are actually bundles of wires as shown in FIG. 5.

FIG. 5 illustrates a control cable (CC) composed of nine signal lines (2; I1 to I9) for transmitting signals I1 to I9 (mixed with the same signal as hereinafter), which is a control cable (CC). 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 shown in FIG. 5, I1 is applied to 9-31V (reference 24V) as the power supply line of the remitter motor M for supplying the wire W, I2 is the common ground line (0V), and I3 is the inching ( During inching, I5V is applied as a switch line for idling the feeding motor (M), I4 is applied with 24V as a switch line of the torch (T), and I5 cuts off 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 control cable CC of the related art does not actually transmit data to each of the signal lines 2; I1 to I9, but merely extends several tens of meters of the wire of the open / close switch.

Although the idea of reducing the signal lines 2 (I1 to I9) of the conventional control cable CC to reduce the cross section of the cable assembly 1 by digitizing such signal lines I1 to I9 is not conventionally conceived. Essentially, the use potential of each signal line (2; I1 to I9) is different from each other, and a large number of relays and solenoids are required, so that the cost is greatly increased and the power that can actually drive switches composed of relays or solenoids, etc. The digital control system has not been proposed or put to practical use in this field because it is considered impossible to transmit the

Accordingly, the present invention has been made in view of the above-mentioned problems, and the main 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. .

In order to achieve the above object, the control system according to the present invention includes an A / D conversion unit for A / D conversion of a plurality of control signals, and an A / D conversion for time division of a digital signal to be transmitted as a serial signal. A control unit provided in the wire feeder, the 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 the reproduction signal from the reception control unit; And an amplifying part for amplifying the analog signal from the D / A converting part to the required potential.

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

Figure 2 is an exploded perspective view of the main portion showing the connection of the conventional cable and hose.

Figure 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 a conventional welding cable assembly.

5 is a block diagram showing a conventional control system.

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

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

Fig. 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 welding 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 to I9: Control Signal I10: Serial Signal

CPU1: Transmission control unit CPU2: Reception control unit

A / D: A / D converter D / A1 to D / A3: D / A converter

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

AMP1, AMP2: amplifier 101: cable assembly

102: signal line 103: conductor cable

104: insulation coating

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Therefore, 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 welding machine itself and the configuration only by adding the present control system to the existing wire feeder and welding machine. 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 1

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 Figure 6, the control system according to the present invention is connected to the signal line 102 (preferably one) of the control cable (CC) the sending unit provided in the welding machine (V) and the receiving unit provided in the wire feeder (F) It is configured.

The transmitting part and the receiving part are preferably configured on a card-shaped circuit board, respectively, and are coupled to the welding machine V and the wire feeder F shown in FIG. 1 and the like, and accordingly, the conventional welding machine V And the wire feeder F does not require any change or addition of the control element as described above.

To this end, the control system of the present invention should reproduce the control signals I1 to I9 at the front end of the sending part of the welding machine V as it is at the rear end of the receiving part of the wire feeder F. Hereinafter, the configuration thereof will be described.

First, referring to the transmitting part of the welding machine V, the control signals I1 to I9, 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 I9 have potentials of 9V to 31V, 15V or 24V, respectively, or the potentials of the digital signals I1 'to I9' outputted to the A / D converter A / D are digital ICs. It has a value of 0V or 5V, which is the output potential of.

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 'through I9' are converted into a series of serial signals I10 through the parallel-to-serial conversion unit P / S, and transmitted to the signal line 102. FIG.

Here, the digital signals I1 'to I9' time-divided by the digital switching in the latch unit LC1 are synthesized as they are in the parallel-to-parallel 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 according to the time division in the latch portion LC1. Preferably, the front end of each signal is divided into the receiver of the welding machine V. FIG. A start pulse for recognizing is added, followed by signal pulses corresponding to each of the control signals I1 to I9.

The magnitude of the control signals I1 to I9 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 power is increased, it is difficult to obtain sufficient power for control even if the receiver is A / D regenerated and amplified. Cases may occur.

Accordingly, in the embodiment shown in FIG. 8, the potential of the power supply line I1 of the power supply motor M, for example, the control signal I1 to I9 is set as the reference potential, and the serial signal I10 of FIG. Is added to this reference potential as a signal potential and transmitted.

The transmission method of FIG. 8 is a method of transmitting a signal potential having a low potential (0 V or 5 V) by using a high potential (9 to 31 V) as a reference wave, and thus, high power can be reproduced by the reference potential. There is this.

6, filter units FT1 and FT2 are provided at the front and rear ends of the signal line 102, respectively, so that noise from a power cable PC (not shown in FIG. 6) or the like adjacent to the signal line 102 is mixed. Shuts off and prevents reverse current flow.

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

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 high 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 for serially converting the serial signal I10, which is time-divisionally transmitted through the signal line 102, into a parallel control signal I1 to I9 in parallel and reproducing the reception unit on the wire feeder F side. 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 reproducing 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 D / A conversion units D / A1 to D / A3 that reproduce them as analog signals.

However, since the driving potential of IC and the like used for digital control is 0V to 5V, the control signals reproduced by the D / A converters D / A1 to DA9 are only the same as 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 conversion units D / A1 to DA3 to amplify the control signal to the required potential to reproduce the original control signals I1 to I9. do.

In this case, the control signals I1 to I9 are not intended to be used as a single potential, but 9V to 31V (power supply of the supply motor M), I5V (inching lamp) or 24V (solenoid valve (SOL) control lamp, etc.). Depending on the various potentials.

Accordingly, the amplification units AMP1 and AMP2 also control signals I1 to I9 are divided into a plurality of amplification units AMP1 and AMP2 having different amplification potentials according to the use potential, and the D / A conversion unit D / A. A1 to DA3) are also preferably configured to be separated in accordance with the respective amplification units AMP1 and AMP2.

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

On the other hand, the greatest effect by the application of the present invention is to be able to significantly reduce the number of signal lines of the power cable of the cable assembly from several to one, accordingly the configuration of the cable assembly as shown in Figures 9A and 9B Can be adopted.

First, in FIG. 9A, a gas hose GH is arranged in a power cable PC, which is composed of a conductive cable 103 arranged in an annular manner in an insulating coating 104. In FIG. According to the present invention, since the signal line 102 of the control cable CC is reduced to three in the illustrated embodiment, the control cable CC can be arranged in the gas hose GH (105). Insulator 102).

According to such a configuration, since the control cable CC does not occupy a separate area, the cross section of the cable assembly 101 is greatly reduced, and the magnetic fields are canceled with each other in the power cable PC that passes through high power to form a large magnetic field. Since the control cable CC is arranged therein, there is no fear of noise mixing due to the magnetic field.

Meanwhile, in FIG. 9B, the control cable CC is formed of one signal line 102. Accordingly, the signal line 102 may be formed of one spiral without covering an insulator (105 of FIG. 9A). The configuration becomes simpler.

Therefore, the present invention provides a control system that can be used in addition to the existing welding apparatus as well as easy to handle and use and precise control by extremely simple configuration of the cable assembly.

As described above, an A / D conversion section for A / D conversion of a plurality of control signals and a delivery control section for time-division and outputting the A / D converted digital signals as a serial signal are provided in the welding machine. A reception control unit for reproducing a serial signal applied along the signal line as a parallel signal, a D / A conversion unit for D / A converting a reproduction signal from the reception control unit, and an analog from the D / A conversion unit ( The amplification part in the wire feeder that amplifies analog signal to the required potential makes the configuration of the cable assembly extremely simple, so it is easy to handle and use, and it can be precisely controlled and can be added to the existing welding equipment. It is a feature of the system to provide.

Claims (10)

In the control system of the semi-automatic welding machine for controlling the welding state by sending a plurality of control signals from the welding machine to the wire feeder through the control cable, The welding machine (V) is provided with an A / D converter for A / D converting the plurality of control signals, and a feed control unit for time-dividing the A / D converted digital signal and outputting the serial signal. A reception control unit for reproducing the serial signal applied from the transmission control unit along the control cable as a parallel signal, a D / A conversion unit for D / A converting the reproduction signal from the reception control unit, and the D / A conversion unit And amplifying part provided in said wire feeder (F) for amplifying the analog signal from the signal to a required potential and reproducing said control signal. The method of claim 1, The A / D conversion unit and the transmission control unit, the reception control unit and the D / A conversion unit and the amplification unit are each formed on a circuit board in the form of a card, the welding machine and the wire feeder, respectively, characterized in that the control of the welding machine system. According to claim 1, wherein the delivery control unit, A latch unit for latching the A / D converted digital signal at a predetermined timing; And a parallel-to-serial conversion unit for converting the signal latched by the latch unit into the serial signal. The method of claim 1, wherein the reception control unit, A serial-to-parallel converter for serial-to-parallel conversion of the serial signal; And a latch unit for latching the signals converted therefrom into a continuous signal. The method of claim 1, The amplification unit is a control system of a semi-automatic welding machine, characterized in that a plurality of separation configured in accordance with the use potential of the control signal. The method according to any one of claims 1 to 5, The control system of the semi-automatic welding machine, characterized in that the D / A conversion unit is separated into a plurality in accordance with the amplification unit. The method of claim 1, And 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 method of claim 1, The control system of the semi-automatic welding machine, characterized in that the transmission frequency of the serial signal is more than 1000Hz. The method of claim 8, The control system of the semi-automatic welding machine, characterized in that the transmission frequency of the serial signal is 9000Hz or more. The method of claim 1, The control system of the semi-automatic welding machine, characterized in that the signal line of the control cable consists of one or several.