JPH0417977A - Controller for semiautomatic arc welding machine - Google Patents

Abstract

PURPOSE:To remarkably reduce the number of connection lines between a remote control device and a wire feeder, and a welding power source, to reduce the weight of a trunk cable and to facilitate its handling by adding simple control circuits to the wire feeder side and the welding power source side. CONSTITUTION:The remote control device 13' is incorporated integrally into the wire feeder 17' and the interval between this wire feeder 17' and the welding power source 1' is connected by four connecting lines 25-28 of the trunk cable 22'. The first and second connecting lines 25 and 26 among these are made to feeders to a wire feeding motor 18 from a wire feed control circuit 4 at the welding power source 1' side. A signal from the remote control device 13' to the welding power source 1' is transmitted by the third connecting line 27 and the above-mentioned fourth connecting line 28. The remote control device 13' receives the supply of a power source E3 for control from the welding power source 1' and produces stabilized voltage necessary for operations of circuits. A signal conversion circuit 24 provided on the welding power source 1' side then sends a signal received from the connecting line 27 to the wire feed control circuit 4. The signal conversion circuit 24 can easily discriminate a welding voltage (or current) set signal and a wire feed quantity set signal and synchronous control between the signal conversion circuit 24 and a signal changeover circuit 23 is unnecessary.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a control system for remotely controlling welding voltage (or current), wire feed rate, and arc starting/stopping in a semi-automatic arc welding machine. Regarding equipment.

[Conventional technology]

In recent semi-automatic arc welding machines, a welding control device is built into the welding power source, and a control device for welding is installed between the welding power source and the remote control device for adjusting the welding voltage (or current) and wire feed amount. In many cases, a relay cable is used to connect the feeder and the welding power source.

The connection configuration between the remote control device, wire feeding device, and welding power source in such a semi-automatic arc welding machine is described in the seventh example.
As shown in the figure. As shown in the figure, a welding power source 1 includes a welding torch 1
Welding power source main circuit 2 that supplies welding power to 0 and base metal 11
and an output control circuit 3 that controls the welding voltage (or current).
, a wire feed control circuit 4 that controls the feed amount of the welding wire 12, a sequence control circuit 5 that starts and stops the arc, etc., and includes an input terminal 6, a welding output terminal 7, a connector 8 for a remote control device, and a wire feed control circuit 4. Equipped with a device connector 9.

The remote control device 13 includes a first setting device 14 for setting the welding voltage (or current), a second setting device 15 for setting the wire feed amount, and an inching switch 16 for wire feeding, and the welding power source 1 and are connected to each other by six connecting wires of a relay cable 21. The first setting device 14 and the second setting device 15 receive a control power source E3 from the welding power source side and send a welding voltage (or current) setting signal to the output control circuit 3 and a wire feed control circuit 4. The wire feed amount setting signal (2) for each wire is sent to the connection line individually, and when the inching switch 16 is turned on, the signal is sent to the sequence control circuit 5 via another connection line.

The wire feeding device 17 is connected to the welding power source 1 and the relay cable 22 by four connecting wires, two of which are used as power feeding lines from the wire feeding control circuit 4 to the wire feeding motor 18. The other two wires are connected to the sequence IIT? from the trigger switch 19 built into the welding torch 10. It is used to transmit on/off signals to the 111 circuit 5.

[Problem to be solved by the invention]

As mentioned above, in the conventional semi-automatic arc welding machine, control signals were transmitted between the remote control device, wire feeding device, and welding power source through individual connection lines, which resulted in a large number of connection lines. In this case, a total of 10 connection lines are required. For this reason, when extending the relay cable by 30 to 50 m, the welding power cable 20.20'
If gas hoses (not shown) are included, the weight of the relay cables and hoses alone will be several plus or minus, making handling extremely difficult.

SUMMARY OF THE INVENTION An object of the present invention is to significantly reduce the number of connection wires between a remote control device, a wire feeding device, and a welding power source, and to be easy to handle while satisfying control functions equivalent to those of the prior art. An object of the present invention is to provide a control device for a semi-automatic arc welding machine with high reliability of signal transmission.

[Means for Solving the Problems] In order to achieve the above object, the invention according to claim 1 incorporates a remote control device in a wire feeding device, and a plurality of remote control devices connected between the wire feeding device and a welding power source. Two of the connection wires are used as power supply lines for the control power source from the welding power source to the remote control device, and one of the power supply lines and a third connection line that is not included in the power supply line are connected to the welding voltage ( or current) setting signal and wire feed rate setting signal from the remote control device to the welding power source, and the welding voltage (or current) setting signal is sent to the remote control device side with mutually different voltage ranges as adjustment ranges. and a first and second setter that respectively output a voltage corresponding to a voltage corresponding to the wire feed amount setting signal, and a first and second setter that respectively output a voltage corresponding to A signal switching circuit is provided to send the signal to the third connection line, and the welding power source side discriminates the two voltages received from the third connection line according to the voltage range to which they belong, and outputs the welding voltage (or current) setting signal and wire. The present invention is characterized by the provision of a signal conversion circuit that separates and extracts the feed amount setting signal.

For the same purpose, the invention according to claim 2 is such that one line of the power supply line of the control power source from the welding power source to the remote control device is shared with one line of the power supply line from the welding power source to the wire feeding motor. The invention as set forth in claim 3 is characterized in that the remote control device includes switching cycle changing means for setting the switching cycle of the signal switching circuit to two different cycles corresponding to the on state and off state of the arc starting trigger switch, respectively. 5. The welding power source is provided with a switching period determining means for determining the two periods of the transmission signal and outputting signals corresponding to the on state and off state of the trigger switch, respectively, The invention provides a signal level control means for setting a welding voltage (or current) setting signal sent from the signal switching circuit to zero voltage in response to an on state of an inching switch for wire feeding on the remote control device side, and The power supply side is provided with signal level determining means for determining whether the welding voltage (or current) setting signal is in a zero voltage state and outputting a signal corresponding to the on state of the inching switch.

[Effect]

The basic idea of the present invention is that the welding voltage (or current) setting signal and wire feed amount setting signal are not individually transmitted to the welding power source, but the voltage of the control power source supplied from the welding power source is increased or decreased. Divide into two, assign one to the voltage range of the welding voltage (or current) setting signal, and the other to the voltage range of the wire feed rate setting signal, and apply these two signal voltages to the respective assigned times. The two signal voltages are time-divided and transmitted alternately to the welding power source at a predetermined period, and the two signal voltages received at the welding power source are discriminated based on the voltage ranges to which they belong, and the two signal voltages are divided and extracted. By doing this, the receiving side can distinguish between two signals without synchronizing with the transmitting side, and the number of connection lines can be reduced while taking advantage of the advantages of analog signal transmission, which is less susceptible to noise. .

In addition, this time-division switching cycle can be changed in response to the on and off states of the trigger switch, and the inching switch can be turned on or off by taking advantage of the fact that no welding voltage (or current) setting signal is required during wire feeding. By setting the welding voltage (or current) setting signal to zero according to the state,
A plurality of pieces of control information from a trigger switch or an inching switch can also be transmitted together with the setting signal,
The number of connection lines can be reduced accordingly.

In addition, by incorporating the remote control device into the wire feeding device and sharing one line of the control power supply line from the welding power source to the remote control device with one line of the power feeding line from the welding power source to the wire feeding motor, The number of connection lines can be further reduced, and the number of relay cables can be reduced to one.

[Example] Examples of the present invention will be described below with reference to FIGS. 1 to 6. FIG. 1 is a diagram showing the connection configuration of one embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the signal waveform in the embodiment of FIG. 1,
Portions in FIG. 1 that are equivalent or corresponding to those in FIG. 7 are designated by the same reference numerals.

In FIG. 1, a welding power source 1' includes a welding power source main circuit 2, an output control circuit 3, a wire feeding control circuit 4, a sequence control circuit 5, and a signal conversion circuit 24 to be described later, and has an input terminal 6, a welding output terminal 7 and a connector 9 for wire feeding device.

Unlike the conventional example shown in FIG. 7, the remote control device 13' is integrated into the wire feeding device 17', and the four connection lines of the relay cable 22' are connected between the wire feeding device 17' and the welding power source 1'. 25 to 28 are connected. Among them, the first and second connection lines 25 and 26 are used as power supply lines from the wire feed control device 4 on the welding power source 1' side to the wire feed motor 18,
The second connection line 26 and the fourth connection line 28 are connected to the welding power source 1.
As a power supply line of the control power source E3 from ' to the remote control device 13', one wire 26 of the power supply line is shared with the motor power supply line,
Signals are transmitted from the remote control device 13' to the welding power source 1' through the remaining third connection line 27 and the fourth connection line 28.

In the remote control device 13', the welding type a! Stabilized voltage + necessary for circuit operation is supplied from control power supply E3 from 1'.
Create E. In this case, since a voltage drop occurs in the connection line 26 due to the motor current flowing, it is necessary to stabilize this voltage by some method.

The first setting device 14' of the remote control device 13' is used for setting the welding voltage (or current), and the second setting device 15 is attached to the metal plate.
′ is used to set the wire feed rate, and will be explained below. Said 2
The two setting devices 14' and 15' are potentiometers, and the first setting device 14' controls the welding voltage (or current).
Outputs the voltage ■1 corresponding to the setting signal, and outputs the voltage ■1 corresponding to the setting signal, and
5' is configured to output a voltage 2 corresponding to a wire feed amount setting signal. El and E2 are constant voltages applied to the two setting devices 14' and 15' in the opposite direction to the stabilizing voltage +E, and these constant voltages E, E2 are set to +E/2 or a little larger than that. For example, if 10E is 15■, it should be 7.5 to 8■. As a result, the first setter 14' sets the voltage range of the upper half of the stabilized voltage 1E (from 7.5~8■ to 15V) as the adjustment range,
The second setter 15' sets the voltage range of the lower half of the stabilized voltage 1E (from OV to 7 to 7.5 square meters) as an adjustment range, so that the two voltage ranges do not overlap. Constant voltage E
, , E2 can be made using Zener diodes.

The two setting devices 14' and 15 are located on the remote controller W13' side.
A signal switching circuit 23 is provided together with the signal switching circuit 23, and the signal switching circuit 23 is operated at a duty cycle of 50% at a predetermined period (a fraction of a second to a few tenths of a second), thereby controlling the two setting devices 14' and 15. Voltage V corresponding to the setting signal from '
, , V2 are alternately sent to the third connection line 27. Then, the signal conversion circuit 24 provided on the welding power source 1' side converts the signal received from the connection line 27 into the same signals ■ and ■ as the signal received by the circuit in FIG. 7, and the signal is transferred to the output control circuit 3. , and the signal ■ is sent to the wire feed control circuit 4.

The signal waveform transmitted through the connection line 27 is shown in FIG. 2(a). Here, the signal voltage ■1 is in the range of +e to 10E, and the signal voltage ■2 is in the range of OV to +e.
15' changes according to the adjustment. T is the time allocated to each of the signal voltages Vl and V2.

Assuming T2, the signal voltage V of time T is always larger than the signal voltage ■2 of time T2, so in the signal conversion circuit 24, a voltage larger than +e (+E/2) is used as a welding voltage (or current) setting signal, A voltage smaller than +e (+E/2) can be easily identified as a wire feed amount setting signal, and synchronous control with the signal switching circuit 23 is not required. In order to return the received signal to the two signals (and), the alternately sent signal voltages V, , V2 are taken into separate sample-and-hold circuits, where (2) is amplified twice, and (2) is amplified by a constant voltage E1. All you have to do is subtract the amount and then amplify it twice.

Next, a means for transmitting on/off signals of the trigger switch 19 and the inching switch 16 to the welding power supply side will be described. When the trigger switch I9 is turned on, the switching period of the signal switching circuit 23 is changed to be shorter or longer than when it is turned off. FIG. 2(b) shows an example in which the switching period is shortened. By determining this period using the signal conversion circuit 24, it is possible to generate signals O corresponding to the on state and off state of the trigger switch 19, respectively. When the inching switch 16 is turned on, the switching period of the signal switching circuit 23 is changed to another third period, and the signal converting circuit 24
There is also a method of determining the cycle of Leaving only the voltage vz corresponding to the feed rate setting signal, the voltage corresponding to the welding voltage (or current) setting signal■1
is set to zero, and the signal conversion circuit 24 determines this voltage zero state to generate a signal [F] corresponding to the on state of the inching switch 16.

According to the connection configuration of this embodiment described above, the welding power source 1'
All control signals can be transmitted using only the four connecting wires 25 to 28 connected to the wire feeding device connector 9.
All the connection lines connected to the remote control device connector 8 in FIG. 7 can be abolished.

Another advantage is that conventional products can be used in common for the wire feeding device connector 9 and the relay cable 22'.

Next, specific circuit examples of the signal switching circuit 23 and the signal conversion circuit 24 will be explained.

FIG. 3 shows a specific circuit example of the signal switching circuit 23.

In the figure, 29 is a comparator, 30 is an inversion circuit, and 31 to 3
3 is an analog switch, 01 to C1 are capacitors, and R.

~R7 is a resistor, comparator 29, capacitor C
I and resistors R1 to R2 are astable multivibrator 3
4. The trigger switch 19 is connected in series with the resistor R6 and in parallel with the capacitor C2 between the two wires on the +E side and the 0■ side of the stabilized power supply, so when the trigger switch 19 is off, the connection between C2 and R6 is The control voltage applied to the analog switch 31 from point a is low level (0
In (2), the analog switch 31 is turned off, and in this state, only the resistor R1 is connected to the negative feedback circuit of the comparator 29. Therefore, the astable multivibrator 34 oscillates at a period determined by R and C+, and changes the output voltage of the comparator 29 alternately between high and low levels. The analog switch 32 has a comparator 2
The output voltage of the comparator 29 is applied to the analog switch 33 as a control voltage, and the output voltage of the comparator 29 is applied to the inverting circuit 30.
Since the inverted signal is applied as a control voltage, during the period ('r + time) when the output voltage of the comparator 29 is at a high level, the output voltage 1 of the first setter 14' is applied to the connection line 27 by the analog switch 32. Also, during the period when the output voltage of the comparator 29 is at a low level (time T2), the output voltage 2 of the second setter 15' is sent to the connection line 27 by the analog switch 33, so that the output voltage of the connection line 27 is The signal waveform is as shown in FIG. 2(a).

When the trigger switch 19 is turned on, the control voltage applied from the connection point a to the analog switch 31 reaches a high level (10E
), the analog switch 31 is turned on and the negative feedback circuit of the comparator 29 is connected to the resistor R,,1! :R, are connected in parallel. As a result, the oscillation period of the astable multivibrator 34 becomes shorter than when the trigger switch 19 is off, and accordingly, the switching period of the signal sent to the connection line 27 also becomes shorter, as shown in FIG. 2(b). . Here, the trigger switch 19, analog switch 31, resistors RZ, R6, and capacitor C2 constitute the switching cycle changing means.

On the other hand, the inching switch 16 is connected in parallel with the capacitor C3 between the control input terminal of the analog switch 32 and the stabilized power supply 0Vi41A, so when the inching switch 16 is turned on, the analog switch 32 is turned off. 2 (C).
As shown in the figure, the voltage sent from the first setter 14' to the connection line 27 becomes zero, and only the output voltage (2) from the second setter 15' is sent to the connection line 27.

Here, the inching switch 16 and the capacitor C3 constitute the signal level control means.

4 to 6 show specific circuit examples of the signal conversion circuit 24. In the figure, 35, 36, 37 are comparators, 38 is an inverting circuit, 39 to 41 are analog switches, 42 to 44 are voltage followers, 45.46 is a differential amplifier circuit, 04 to C7 are capacitors, and R8 to R2□ are It is resistance. Analog switch 39, voltage follower 42, capacitor C4 in FIG.
Resistor R11 constitutes the first sample-and-hold circuit 47, and analog switch 40, voltage follower 43, capacitor C5, and resistor R3b constitute the second sample-and-hold circuit 4.
The input sides of these two sample and hold circuits 47 and 48 are connected to connection 1IA27.

In FIG. 4, the signal voltage from connection line 27 is applied to comparator 35 as a positive input. Comparator 35
Since the reference voltage, which is the negative input of When it corresponds to (b) 1, it becomes a high level (+E). This high-level output turns on the analog switch 39 of the first sample-and-hold circuit 47, and the voltage at the vI level held by the capacitor C4 is output from the voltage follower 42. In the differential amplifier circuit 45, a constant voltage E is subtracted from this voltage at the level 1, and the voltage is further amplified twice to produce an output 2. Also, if the input voltage from the connection line 27 is low, that is, as shown in FIG.
When corresponding to ■2 in a) and (b), comparator 3
5 becomes a low level (0■), the analog switch 40 on the second sample-and-hold circuit 48 side is turned on by the signal obtained by inverting this output voltage by the inverting circuit 38, and the signal is held by the capacitor C2. (2) Two levels of voltage are output from the voltage follower 43. And this ■2
The voltage at the level is amplified twice by the differential amplifier circuit 46 and becomes the output (2).

As shown in FIG. 5, as a means for determining the switching period of the transmission signal, the charged voltage of the capacitor C6 due to the high level output O of the comparator 35 is used as the positive input of the comparator 36, and the negative input set by the resistor R2++ R22 is used. The output voltage of the comparator 36 is inverted from low to high by utilizing the fact that the charging voltage of the capacitor C6 becomes higher when the switching period of the transmission signal is longer than the reference voltage of the analog switch 41. is turned on to charge the capacitor C1, and the voltage is set as the output of the voltage follower 44. In this example,
(2) The high level of the output corresponds to the off state of the trigger switch 19.

Further, as a signal level determination means for determining the zero state of the signal voltage ■, as shown in the example in FIG. It is compared with the set reference voltage of the positive input, and when the output becomes zero, the output of the comparator 37 is inverted from low to high, and the output is set as the [F] output. In this example, the high level of the output (2) corresponds to the on state of the inching switch 16.

〔Effect of the invention〕

According to the present invention, by simply adding a simple control circuit to the wire feeding device and the welding power source, the number of connection wires between the remote control device and the wire feeding device and the welding power source can be significantly reduced. By reducing the weight of the relay cable, its handling can be made easier.

One way to reduce the number of connection wires is to have all the control circuits related to wire feeding built into the wire feeding device, but this method creates the power supply for control within the wire feeding device. For reasons such as the need for a control transformer, the wire feeding device becomes heavy and bulky, making it difficult to handle and having poor impact resistance. The additional parts on the feeder side only need to be about 1 piece of a small printed circuit board.
Since it does not require a control transformer, it does not have the above drawbacks.

In addition, the method of transmitting the setting signal as a pulse signal by V-F (voltage-frequency) conversion has the disadvantage that it is easily affected by the noise generated by the welding current, but in the present invention, the setting signal is transmitted as an analog signal. Since it uses a time-division transmission method, there is no such drawback and stable operation can be achieved.

[Brief explanation of drawings]

Fig. 1 is a connection configuration diagram showing one embodiment of the present invention, Fig. 2 is an explanatory diagram of signal waveforms in the embodiment of Fig. 1, and Fig. 3 is a specific circuit example of a signal switching circuit provided on the remote control device side. FIGS. 4 to 6 are diagrams showing specific circuit examples of a signal conversion circuit provided on the welding power source side. FIG. 7 is a connection configuration between a remote control device, a wire feeding device, and a welding power source according to the prior art. It is a diagram. 1'... Welding power source, 3... Output control circuit, 4...
Wire feeding control circuit, 5... Sequence control circuit, 1
0...Welding torch, 13'...Remote control device, 14
'...First setting device, 15'...Second setting device, 1
6... Inching switch, 17'... Wire feeding device, 18... Wire feeding motor, 19... Trigger switch, 23... Signal switching circuit, 24... Signal conversion circuit, 25-28... Connection line, E,... Control power supply, 19, 31. Cz, Rz, Rh...
- Switching cycle changing means, 16. C3...Signal level control means, 36°41, 44. C,, C,, R2° to R24...Switching cycle determining means, 37. Rzs〜R
z, . . . signal level determination means.

Claims (1)

[Claims] 1. A welding power source having control functions such as welding voltage (or current), wire feed amount, and arc starting/stopping, a wire feeding device connected to the welding power source, and the welding power source. A semi-automatic device that is connected to a welding torch, etc., and has a remote control device (hereinafter referred to as the remote control device) for externally adjusting the welding voltage (or current) and wire feed amount, and a trigger switch for starting the arc. In the arc welding machine, the remote control device is built into the wire feeding device, and two of a plurality of connection lines connecting the wire feeding device and the welding power source are controlled from the welding power source to the remote control device. The welding voltage (or current) setting signal and wire feed rate setting signal are transmitted from the remote control device to one line of the feeding line and a third connection line not included in the feeding line. It is configured to transmit to a power source, and outputs a voltage corresponding to a welding voltage (or current) setting signal and a voltage corresponding to a wire feed rate setting signal to the remote control device, respectively, with different voltage ranges as adjustment ranges. a signal switching circuit that alternately switches the voltage output from the two setting devices at a predetermined period and sends it to the third connection line; The two voltages received from the third connection line are determined according to the voltage range to which they belong, and the welding voltage (
A control device for a semi-automatic arc welding machine, comprising a signal conversion circuit that separates and extracts a wire feed amount setting signal and a wire feed amount setting signal. 2. The semi-automatic device according to claim 1, wherein one line of the power supply line of the control power source from the welding power source to the remote control device is shared with one line of the power supply line from the welding power source to the wire feeding motor. Arc welding machine control device. 3. A switching period changing means is provided on the remote control device side for setting the switching period of the signal switching circuit to two different periods corresponding to the on state and off state of the trigger switch, respectively, and a transmission signal is provided on the welding power source side. 2. The control for a semi-automatic arc welding machine according to claim 1, further comprising a switching period determining means for determining the two periods and outputting signals corresponding to the on state and off state of the trigger switch, respectively. Device. 4. A signal level control means is provided on the remote control device side to set the welding voltage (or current) setting signal sent from the signal switching circuit to zero voltage in response to the on state of the inching switch for wire feed, and the welding power source side Claim 1 characterized in that the welding voltage (or current) setting signal is provided with a signal level determining means for determining a zero voltage state of the welding voltage (or current) setting signal and outputting a signal corresponding to the on state of the inching switch. Control device for the semi-automatic arc welding machine described.