JPS58168474A - Arc welding machine - Google Patents

Abstract

PURPOSE:To obtain an arc welding machine which is capable of remote-controlling various welding conditions from a place being at hand of a worker, by connecting a signal generator for outputting (n) kinds of selectable signals, in series to a contact of a switch for instructing welding start, wire feed, gas flow-out, etc. CONSTITUTION:Before welding is started, a worker selects a signal generator 2 suitably, and sets it so that a specified signal among (n) kinds of signals can be outputted. An output of this generator is not transferred to a discriminating circuit 5 until a switch 1 is depressed, but when the switch 1 is depressed, one among (n) kinds is discriminated by the circuit 5 through a cable 3, and its discrimination result is outputted to a welding condition setting circuit 6. On the other hand, in case of starting the welding, when the switch 1 is depressed and closed, an output of the circuit 2 is provided to an input terminal of a starting circuit 4, too. Subsequently, the circuit 4 detects a variation of this input signal, supplies a start signal to a welding condition control part 7, and the control part 7 controls an output by an output signal of the circuit 6, corresponding to a signal discriminated by the circuit 5, and executes welding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an arc welding method that allows the operator to remotely adjust welding conditions such as welding voltage, contact current, power consumption, wire feed speed, or welding speed. It's about machines. When performing arc welding, it is often necessary to change the welding conditions during the r8 welding due to changes in the welding posture or changes in the shape of the #4 workpiece. Furthermore, in shipyards and ironworks that handle large-scale liquid baths, the installation location of the bath source and the actual work area are often far apart. In such a case, it would be very inconvenient and inefficient to go to the bath welding area 1!11#i to change the welding conditions to open the welding conditions. Therefore, prior to welding, a combination of multiple expected welding conditions is preset in the welding power source, and the operator can manually select and carry out the appropriate combination of these preset conditions as necessary. You are required to do so.

Conventionally, devices with this kind of function have a rotary switch at the operator's hand, and by switching it as necessary, the operator selects a variable resistor, etc. on the welding power source connected to the rotary switch. Or, the torch switch for welding start command provided on the welding torch can also be used to change the conditions, count the length of the torch switch closing time and the number of opening/closing operations, and use the results to determine the welding conditions. Methods that perform switching have been proposed. However, although the former of these conventional methods has the advantage that the type of condition selected by the operator can be read from the position of the rotary switch, a multi-core cable is used to guide the signal from the rotary switch to the welding power source. This increases the number of cables and increases the rate of disconnection accidents.In addition, semi-automatic grooving, in which the welding torch is directly operated by the operator, does not require an increase in the number of cables, but the welding conditions have to be changed. In order to distinguish between the operation of the torch switch for switching and the operation of the torch switch for starting welding, it is determined that welding has started only when the closing time of the torch switch continues for a certain period of time or longer. The closing of the torch switch for switching the welding conditions is completed within this set time,
This opening/closing operation is repeated a predetermined number of times. Therefore, the setting time for this needs to be at least 0.5 seconds or more in order to ensure the reliability of the switching operation. For this reason, after pressing the torch switch to start welding, welding actually starts after this set time has elapsed.
The response of the welding machine to the operation of the torch switch is slow, resulting in extremely poor operability.

Moreover, if the torch switch is accidentally released during this time, the welding conditions will be changed unnecessarily against the operator's will. Furthermore, if chatter occurs in the contacts of the torch switch when the contacts are closed, there is a risk that the conditions may be changed depending on the number of openings and closings due to this chattering.

Furthermore, it is impossible for the operator to confirm at all which welding conditions selected in this way are the actual conditions. This, coupled with the possibility of malfunctions occurring due to the various causes mentioned above, forces the operator to be extremely nervous about operating the torch switch, and gives a great sense of anxiety. Furthermore, despite such careful operation, there is a serious drawback in that it is not possible to reliably prevent the occurrence of defective welding due to the fact that the target conditions have not been selected.

The present invention eliminates the shortcomings of conventional devices, and provides an arc that does not require an increase in cables, has good operability, and is equipped with a welding condition remote switching function that allows the operator to constantly check the selected welding conditions at hand. The company provides welding machines.

FIG. 1 is a configuration diagram showing an embodiment of the present invention, which is a signal generator that generates n types of different signals, for example, voltage signals of different values, according to the operator's selection, and its output is a switch 1. It is connected in series with the contact point and is installed in the operator's hand, for example, directly on or near the welding torch or hand control box. 3 welds the signals from the switch 1 and the signal generator 2, and is operated by the change in the input signal accompanying the closing of the switch 1. Reference numeral 5 denotes a discrimination circuit for discriminating the type of input signal, which discriminates which of n types the output signal from the signal generator 2 inputted by closing the switch 1 is. This is a welding condition setting circuit that receives the discrimination result of the output signal of the signal generator 2 discriminated by the discrimination circuit 5 and sets the welding conditions corresponding to each of them. In a fully automatic welding machine that performs welding using a cart, this circuit also sets the welding speed. Reference numeral 7 denotes a welding condition control section which receives the output signal of the welding condition setting circuit 6 and obtains a predetermined welding output.The circuits after the starting circuit 4 and the discriminating circuit 5 whose outputs are controlled according to external signals are in the working state. It can be built into a welding wire or welding machine control device that is far away from the user's position, or it can be installed as a separate control box very close to these.

In the embodiment shown in FIG. 1, before starting welding, the operator appropriately selects the signal generator 2 and controls it so that a specific signal out of n types of signals is output. The output of this signal generator 2 is not transmitted to the discrimination circuit 5 until the switch 1 is pressed, but when the switch 1 is pressed, the discrimination circuit 5 passes through the cable 3 and discriminates which of the nM odes it is. The results are output to the welding condition setting circuit 6. On the other hand, when the switch 1 is pressed to close the circuit at the start of welding, the output of the signal generating circuit 2 is also supplied to the input terminal of the starting circuit 4. The starting circuit 4 detects the change in this input signal and supplies the starting signal to the welding condition control section 7, and the welding condition control section 7 outputs the output signal of the welding condition setting circuit 6 according to the signal discriminated by the discriminating circuit 5. Welding is performed by controlling the output.

The signal generator 2 may have various specific examples as long as it generates a plurality of different signals. 2 to 5 show connection diagrams of specific embodiments of the signal generator 2. In FIG. Each figure is configured to output n types of different voltage signals selected by respective rotary switches.

In Figures 2 to 5, S is an n-stage rotary switch, and el to en are DC power supplies with different voltages, for example, 0 < el < el <...
(En batteries are used. Ea to Ec are DC power supplies, rQ to rfi are resistors, and resistors r1 to rfi each have different values. Rb and Rc are resistors, and ZDI to ZDn are They are constant voltage diodes with different voltages, and a and b are output terminals.

In FIGS. 2 and 3, the voltages Vzl to V of the DC power sources e1 to en or constant voltage diodes ZD1 to ZDn selected by the rotary switch S
A voltage of z n appears between output terminals a and b. Also the fourth
In the figure, the voltage of a DC power source Eb is divided by a resistor Rb and resistors r1 to rn. When the rotary switch S is set to the i-th position (ri is the resistance value of the i-th resistor ri), the output terminal a-
It is output between b. In FIG. 5, a DC power source Ec and a resistor Rc are provided separately from the signal generator 2, and a voltage opposite to that in the example of FIG. 4 is output between output terminals a and b. Therefore, if the resistance values rl to rn of the resistors r1 to rn in FIGS. 4 and 5 are set stepwise so that they become r+ (Vg (・
...(A voltage of vn is obtained, and in the example of Fig. 5, V
+ ) Vg )...>vn voltage is obtained.

It is a connection diagram showing an embodiment of a discrimination circuit 5 that discriminates the type of input signal from the signal generation circuit 2 transmitted by the closing of the starting circuit 4 and the switch 1 which commands, and LO to Ln indicate the level of the input voltage. This is a level detection circuit that detects and generates a logical output when a voltage within a set range is input. TRQ to TRn are transistors that are made conductive by the output of the level detection circuits LO to Ln. The connection is determined depending on the output format of the level detection circuits LO to Ln. Also, CRQ to CRn are relays, and each series transistor T
It is excited by conduction of RQ to TRn. Also Ed
is a DC power supply. In Fig. 6, the level is determined by the discrimination circuit 5.
Configure.

FIG. 7 is a connection diagram showing a specific embodiment of the level detection circuits LO to Ln used in the starting circuit and discrimination circuit of FIG. 6. In the same figure, R51 to R53 are resistors,
C51 is a capacitor, ZnS3 and ZD52 are constant voltage diodes, D51 and D52 are diodes, oP5
1 and OF22 are operational amplifiers, NAND51 is NAN
This is the D gate. Further, Ef is a DC power supply that supplies voltage to constant voltage diodes ZD51 and ZnS2 for level setting, and operational amplifiers OP51 and op52.
A power supply circuit for operating the is not shown. The operation of the level detection circuit shown in FIG. 7 will be explained with reference to the explanatory diagram shown in FIG. In FIG. 8 IC, the horizontal axis represents the magnitude of the input voltage vi, and it is assumed that the voltage increases toward the right side of the diagram.

Further, (1) and (V2) indicate changes in the output voltages of the operational amplifiers OP1 and O12, and the values are approximately the same for both, but are slightly different from each other in the figure for ease of understanding. VO indicates the output voltage of the NAND gate NAND51. Also v
Z51 and vz52 are the Zener voltages of the constant voltage diodes ZD51 and ZnS3, vz51 indicates the lower limit of the detection voltage level, and v252 indicates the upper limit, and the output voltage is output while the input voltage v1 is Vz51 < Vi < V, 52. is now available. In Fig. 7, while the input voltage vt is Vi (V z 51), the output of the operational amplifier OPI is -v ((v (forward voltage drop of diode D51 or D52), ■+ ) v z
51, the output of the operational amplifier op1 is the operational amplifier op
It rises to a positive saturation output of 1. Further, while the input voltage Vi reaches v+ (v z 52 ), the output of the operational amplifier OP2 becomes a positive saturation voltage, and when it reaches V r ) V z 52 , the output of the operational amplifier OP2 drops to −Vf.

Therefore, the input voltages v1 and 2 of the NAND circuit NAND51 change according to the value of the input voltage vi, as shown in FIG. As a result, the NAND circuit NAND51
As shown in the lower part of FIG. 8, the output is an O volt signal only when the input voltage Vi to the level detection circuit is between V, 51 < Vi < V, 52.
The transistors TRQ to TRn shown in FIG. 6, which receive this output in their base circuits, become conductive and the relays connected in series with each transistor are energized. If the constant voltage diodes ZD51 and ZnS3 are selected in accordance with each level detector so that the Zener voltages v251 and v252 are in the middle of the width of change in the output voltage of the signal generator 2, the signal generator 2 It is possible to reliably determine the type of output signal from the When using the circuit shown in FIGS. 2 to 4 as the signal generator 2, the input voltage Vi is zero until the switch 1 for welding start command is opened, and the input voltage Vi is zero at the same time as the switch 1 is closed. The voltage rises to a level corresponding to the setting of the rotary switch S.

Therefore, the level detection circuit LO used in the starting circuit 4 detects when the input voltage rises from zero to a certain value or more, that is, to more than the lowest value of the output voltages of the signal generator 2 selected by the rotary switch S. For example, the output signal of the signal generator 2 may be 3v, 6v,
If it is class 34 of gv, the lower limit of the level detection circuit LQ should be 2V and the upper limit should be about 10V, taking into account the voltage drop in the middle of the cable, and the lower limit of the level detection circuit L1 is 2■, the upper limit is 4■, The lower limit of level detection circuit L2 is 5
The voltages of the constant voltage diodes used in the respective level setters may be selected so that the upper limit of V is 7■, the lower limit of the level detection circuit L3 is 8■, and the upper limit is IOV or more. Furthermore, when using the embodiment shown in FIG. 5 as the signal generator 2, before the switch 1 is closed, the DC power source Ec
is supplied as an input signal to the level detection circuit, and when switch 1 is closed, the input voltage changes to this voltage E.
c to a value divided by one of the resistors r1 to to selected by the rotary switch S and the resistor Rc. Therefore, in this case, it is sufficient to use a level detection circuit LQ that detects at least when the input signal has decreased from Ec to near the maximum voltage selected by the rotary switch S, and in this case also, the level detection circuit L1 The settings of Ln to Ln are the same as in the previous case.

FIG. 9 is a connection diagram showing a specific embodiment of the welding condition setting circuit 6 for setting the welding conditions for the welding condition control section 7 in response to the output of the discrimination circuit 5; For example, the normally open contact CR1a of the output relay of the variable resistor ■R1 to VRn of the discrimination circuit 5 that sets the welding voltage.
to CRna, and the output of each variable resistor is received by an OR circuit consisting of diodes DI to Dn and supplied as an output voltage setting signal to a welding condition control section 7, for example, a welding power source. In addition to the output voltage of the welding power source, the welding conditions covered by the present invention include the output current, the feeding speed of the consumable electrode, and the welding speed, and it is necessary to switch each of these 4t welding conditions at the same time. In this case, it is necessary to provide a plurality of sets of welding condition setting circuits 6, each with a circuit similar to that shown in FIG.

In the above embodiments, the welding conditions are switched by determining the magnitude of the voltage signal, but the present invention is not limited to this. For example, the present invention is not limited to this. The present invention can also be implemented by using a vibrator that generates a oscillator and using a circuit for determining the frequency of the input signal as the determining circuit. It goes without saying that each circuit can be constructed of a non-contact type circuit using a semiconductor integrated circuit instead of a contact type circuit as shown in the example.

The output of the signal generator is led to the discrimination circuit through the two-core cable of the welding start command switch, and it is determined which signal corresponds to it to set the welding conditions, so there is no need to increase the number of control cables. Since there is no cable disconnection, there is no increase in cable breakage accidents, and there is no loss of operability. The selection of welding conditions is based on the adjustment position of the signal generator installed at the worker's hand.
For example, since it can be confirmed by the notch position of a rotary switch, it is possible to always set reliable welding conditions, and since it can be visually confirmed, mental burden on the operator can be eliminated. Furthermore, since the selection of conditions can be performed using a rotary switch, the conventional command that counts the number of openings and closings of the pushbutton switch and the selection of welding conditions are performed by completely different control systems, so there is no waiting time when starting m. It has many advantages such as extremely high efficiency of work without any problems.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an embodiment of the present invention, Figs. 2 to 5 are connection diagrams showing an embodiment of the signal generator, and Fig. 6 is an explanatory diagram showing an embodiment of the present invention.
The figure is a connection diagram showing an example of a starting circuit and a discrimination circuit, FIG. 7 is a diagram suitable for the embodiment of FIG. 6, and FIG. 9 is a concrete example of the welding condition setting circuit. 5... Discrimination circuit, 6... Welding condition setting circuit, 7... Welding condition control section, S... n stage rotary switch. Representative Patent Attorney Hiroshi Nakai Figure 4 Figure 5 L --------4--od Procedure Amendment (Voluntary) April 29, 1980 Commissioner of the Japan Patent Office 1. Indication of Case 1988 Patent Application No. 52711 2, Name of the invention Arc welding machine 3, Relationship with the amended person's case Patent applicant: 2-1-11 Tayo, Yodoyou-ku, Osaka (026) Osaka Transformer Co., Ltd. 4, Agent Address 2-1-1 Tanyo, Yodoyo-ku, Osaka 532
No. 1 [Contact phone number (06) 301-1212] 5
, Date of amendment order Voluntary

Claims (1)

[Scope of Claims] 1. An arc welding machine equipped with a switch that commands the start of welding, the movement or movement of the electrode wire, the discharge of shielding gas, etc., either singly or in a batch. N types (n≧2) for switching welding conditions are connected in series with the contacts of the switch near the switch.
a signal generator that generates a selectable signal of n (an integer of
a discrimination circuit for determining which of the types of signals corresponds to the signal; n sets of welding condition setting circuits selected by the output of the discrimination circuit; and an input terminal connected in parallel with the discrimination circuit to close the switch. The welding machine 2 includes a starting circuit that issues an operation start signal, and a welding condition control section that obtains an output according to the output of the welding condition setting circuit, the signal generator comprising an n-stage changeover switch and The arc welding machine according to claim 1, comprising n voltage sources of different voltages each connected in series to the changeover switch. 3. The signal generator includes a DC power supply, a series circuit of n sets of constant voltage diodes and resistors connected in parallel to the DC power supply, and selectively outputs terminal voltages of the n constant voltage diodes. The arc welding machine according to claim 1, comprising an n-stage changeover switch for leading to the terminal. 4. The signal generator is connected in series with a DC power source, an n-stage changeover switch, and the n-stage changeover switch to divide the output voltage of the DC power supply into voltages of different values in each of the n stages. The arc welding machine according to claim 1, comprising a resistor. 5. The signal generator includes an n-stage changeover switch and n resistors of different values each connected in series to the changeover switch, and the series circuit of the changeover switch and the resistor is separately provided. The arc welding machine according to claim 1, wherein the arc welding machine is connected to a series circuit of a DC power supply and a resistor to divide the output voltage of the DC power supply into n different voltages. 6. The arc welding machine according to claim 1, wherein the signal generating circuit is composed of n unit circuits that generate different types of signals, and can be used by replacing them as necessary. 7. The arc welding according to any one of claims 1 to 6, wherein the discrimination circuit is n sets of level detection circuits that each output an output when a signal in a specific voltage range is input. Machine. 8. The arc welding machine according to any one of claims 1 to 7, wherein the starting circuit is a level detection circuit that outputs an output when the input voltage decreases from substantially zero to a certain amount or more. 9. The arc welding machine according to any one of claims 1 to 7, wherein the starting circuit is a level detection circuit that outputs an output when the input voltage drops by a certain amount or more from the initial voltage. 10. The arc welding machine according to claim vJ1, wherein the signal generation circuit includes a vibrator that generates n types of signals with different frequencies, and the discrimination circuit is a circuit that discriminates the frequency of the input signal. . 11. The bath contact condition setting circuit is a circuit for setting a combination of a plurality of welding conditions such as welding voltage, welding current, and wire feeding speed according to an input signal. The arc bath welding machine according to any one of Item 10.