JPH0329507B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an arc welding machine that allows an operator to remotely adjust welding conditions such as welding voltage, welding current, feeding speed of consumable electrode wire, or welding speed.

When performing arc welding, it is often necessary to change welding conditions during welding due to changes in welding posture, changes in the shape of the workpiece, etc. Furthermore, in shipyards, ironworks, and the like where large objects to be welded are handled, the installation location of the welding power source and the actual work location are often far apart. In such a case,
It is very inconvenient and inefficient to go to the welding power source and switch the welding conditions every time the conditions are changed. Therefore, prior to welding, a combination of multiple expected welding conditions is preset for 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 been equipped with a rotary switch at the operator's hand.
By switching this as necessary, you can select a variable resistor on the welding power source connected to this rotary switch, or a torch switch for welding start command provided on the welding torch. A method has been proposed in which the welding conditions are switched based on the results by counting the length of the torch switch's closing time and the number of opening/closing operations. 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, in order to guide the signal from the rotary switch to the welding power source, welding control device, etc. It is necessary to use multi-core cables, which not only increases the number of cables and increases the rate of disconnection accidents, but also significantly impedes work efficiency in semi-automatic welding where the welding torch is directly operated by the operator. It was hot. In the latter case, the number of times the torch switch is pressed does not increase the number of cables, but it is necessary to close the torch switch in order to distinguish between the operation of the torch switch to change the welding conditions and the operation of the torch switch to start welding. Welding is determined to start only when the time has continued for a certain period of time. The closing of the torch switch for switching the welding conditions is completed within this set time, and this opening/closing operation is repeated a predetermined number of times. Therefore, the setting time for this is at least necessary to ensure the reliability of the switching operation.
0.5 seconds or more is required. For this reason, after the torch switch is pressed at the start of welding, welding does not actually start until after this set time has elapsed, and the welding machine's response 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. For this reason, the operator is forced to be extremely nervous when operating the torch switch, giving him a great sense of anxiety. Furthermore, despite such careful operations, it is not possible to reliably prevent the occurrence of defective welding due to the fact that the target conditions have not been selected, and it is not possible to change any welding conditions during welding. It has a serious drawback.

The present invention eliminates the drawbacks of such conventional devices, and
The present invention provides an arc welding machine equipped with a welding condition remote switching function that does not require an increase in cables and has good operability.

FIG. 1 is a configuration diagram showing an embodiment of the present invention,
In the figure, 1 is the first switch connected in series with the first diode DR1, and is used to start welding, feed the electrode wire in small increments, and test discharge the shielding gas. This is the first switch for instructing a single item or a plurality of items at once. A second switch 2 is connected in series with the second diode DR2, and like the first switch 1, it is installed near the operator's hand, for example, directly on or near the welding torch or hand control box. A first switch consisting of this first switch 1 and a first diode DR1
The series circuit consists of a second series circuit consisting of a second switch 2 and a second diode DR2, and diodes DR1 and DR2 connected in parallel with each other so as to have opposite polarities. It is connected to the welding machine main body, for example, to a welding power source or an AC power source 6 provided near it. 4 is a first detection circuit that detects the current flowing out from the AC power supply 6 when the first switch 1 is closed, and 5 is a second detection circuit that detects the current flowing out from the AC power supply 6 when the second switch 2 is closed. This is a detection circuit. 7 is a starting circuit that receives the output of the first detection circuit 4 and outputs an operation start signal; 8 is a counting circuit that receives the output of the second detection circuit 5 and counts the number of times the second switch 2 closes. Yes, the number of stages is the number of required welding conditions n
An n-stage repetition counter equal to is used. 9
is a welding condition setting circuit which receives the counting results of the counting circuit 8, selects and outputs welding conditions corresponding to the counting results from n sets of welding conditions set in advance. 10 and 11 are welding condition setting circuits 9
10 is a welding power source that outputs welding power according to the output of the starting circuit 7, and its output voltage and current are determined by the output of the welding condition setting circuit 9. determined by. Reference numeral 11 denotes a consumable electrode feeding device that starts feeding upon receiving the output of the starting circuit 7, and its feeding speed is determined by the output of the welding condition setting circuit 9. As these welding power source 10 and consumable electrode feeding device 11, a known welding power source and feeding device whose output can be set by an external signal can be used. As shown in the figure, the welding condition setting circuit 9 is provided separately from the welding power source 10 and the consumable electrode feeding device 11, and also includes a welding condition setting device and a consumable electrode feeding device having a plurality of built-in welding condition setting devices. It is also possible to directly input the outputs of 8 and select them.

In the embodiment shown in FIG. 1, when the operator closes the first switch 1, the detection circuit 4 detects this and supplies an output to the starting circuit 7. The welding power source 10 and the consumable electrode feeder 11 are activated by the output signal of the activation circuit 7 to start welding. On the other hand, when switching the welding conditions, the second switch 2 is closed a required number of times. This closed circuit signal is detected by the second detection circuit 5, and the number of closed circuits is counted by the counting circuit 8. The welding condition setting circuit 9 receives the counting result of the counting circuit 8 and outputs the welding conditions preset according to the input signal to the welding power source 10 and the consumable electrode feeding device 11 that constitute the welding condition control section. Control. This switching of welding conditions involves closing the first switch 1 and the second switch 2 using the AC power source 6.
Since this is detected by the detection circuits 4 and 5, the welding process can be carried out regardless of whether the first switch 1 is pressed and welding is in progress.

FIG. 2 is a connection diagram showing a specific example of the detection circuit 4 shown in FIG. is a smoothing capacitor. Further, a and b are terminals, and correspond to terminals a and b of the first detection circuit 4 in FIG. In the example of Figures 1 and 2, the first
When switch 1 is closed, relay CR41 transfers current from AC power supply 6 to relay CR41 and resistor R.
41, and diode R41, which are excited and the normally open contact CR41a is closed. This contact output is supplied to the starting circuit 7. As the starting circuit 7, if welding or feeding of consumable electrodes is performed only while the switch 1 is pressed, the relay CR41 is used.
The welding power source 10 and the feeding device 11 can be started using the contacts directly, and the starting circuit 7 does not need to be particularly provided and can be used in common with the first detection circuit 4.

Furthermore, in order to create a welding machine that starts welding when the first switch 1 is closed once and ends welding when it is closed again, a flip-flop circuit operated by the output of the detection circuit 4 can be used as the startup circuit 7. good.

Figure 3 shows the detection circuit 5 and counting circuit 8 in Figure 1.
2 is a connection diagram showing a specific embodiment of the DR51, in which c and d correspond to terminals c and d, respectively, of the second detection circuit 5 in FIG.
is a diode connected to the same polarity as the second diode DR2 in FIG. 1, R51 is a resistor,
C51 is a smoothing capacitor. CRS is an n-stage stepping relay that operates on DC and whose contacts advance one step with one voltage application. Connecting.

In the same figure, diode DR51 and resistor R5
1. Stepping relay CRS and capacitor C51 constitute a second detection circuit, and contact CRC of stepping relay CRS and relays CR1 to
CRn constitutes a counting circuit. Although not shown, it is necessary for this stepping relay CRS to return the starting position, that is, the contact point CRC to the 1 position, before selecting the welding conditions. Stepping relay is the means for this recovery.
When using a CRS equipped with a separate reset coil, it is sufficient to obtain a signal indicating the end of one welding from the welding machine body, for example from the welding power source, and drive it to perform automatic return. If there is no reset coil, a timer circuit is provided and a second
It may be configured such that when the switch 2 is pressed continuously for a time set on a timer or longer, the robot automatically advances and stops when it reaches the first position.

Figure 4 shows the welding power source 1 receiving the output of the counting circuit 8.
This is a connection showing a specific example of a welding condition setting circuit 9 for setting welding conditions for 0 and feed speed control device 11. Equipment VR
1 to VRn are selected by the normally open contacts CR1a to CRna of the output relay of the counting circuit 9, and the output of each variable resistor is selected by the OR consisting of the diodes D1 to Dn.
This signal is received by the circuit and supplied as an output voltage setting signal of the welding power source 10. In addition, the welding conditions covered by the present invention include the output current in addition to the output voltage of the welding power source, the feeding speed of the consumable electrode, and the welding speed, but if it is necessary to switch each of these welding conditions at the same time, It is necessary to provide a plurality of sets of welding condition setting circuits 9, each with a circuit similar to that shown in FIG.

In each of the specific embodiments shown in FIGS. 2 to 4, a contact type using a relay has been described, but the present invention applies to the closing of switches 1 and 2 connected in series to diodes DR1 and DR2. As long as the start of operation and the switching of welding conditions can be distinguished by detecting the It may be detected by a circuit, and the counting circuit 8 may also be a non-contact type counter such as a shift register.

As described above, in the arc welding machine of the present invention, the first diode is connected in series with the first switch that commands the start of welding, the inching feed of the consumable electrode, the discharge of shielding gas, etc. A second series circuit is formed by connecting in series a second switch that commands switching of welding conditions and a second diode, and the first series circuit and the second series circuit are connected in series. The first diode and the second diode are connected in parallel with opposite polarity and installed near the operator's hand, and this parallel circuit is installed at or near the welding machine power supply using a two-core cable. The system connects the switch to an AC power source and detects the closing of both switches based on the direction of the outflow current from the AC power source to distinguish between starting the operation and switching the welding conditions. There is no need to increase cable breakage, and there is no increase in cable breakage accidents, and there is no loss of operability. Furthermore, since the operation start command and selection of welding conditions are performed by completely separate control systems, there is no waiting time when starting welding, and conditions can be easily switched even during welding. It has many advantages such as extremely high work efficiency.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is a connection diagram showing an embodiment of the first detection circuit, and Fig. 3 is a connection diagram showing an embodiment of the second detection circuit and counting circuit. , FIG. 4 is a connection diagram showing an embodiment of the welding condition setting circuit. 1...First switch, 2...Second switch, DR1...First diode, DR2...Second diode, 4...First detection circuit, 5...
Second detection circuit, 6...AC power source, 7...Start circuit, 8...Counting circuit, 9...Welding condition setting circuit.

Claims (1)

[Claims] 1. A first switch connected to an AC power supply;
a second series circuit consisting of a second switch connected in parallel to the first series circuit, and a second diode having a polarity opposite to that of the first diode. a first detection circuit that detects the closing of the first switch according to the direction of the current flowing out from the AC power source; and a first detection circuit that detects the closing of the second switch according to the direction of the current flowing out from the AC power source. a second detection circuit that detects when the sensor is on, and a startup circuit that commands the start of welding, inching of the consumable electrode wire, release of shielding gas, etc. individually or collectively based on the output of the first detection circuit. and counting the number of times the second switch is closed in response to the output of the second detection circuit.
a welding condition control unit that obtains an output according to the output of the welding condition setting circuit; a counting circuit of stages (n≧2 integer); Arc welding machine equipped with. 2. The arc welding machine according to claim 1, wherein the welding condition setting circuit is a circuit that sets a combination of a plurality of welding conditions such as welding voltage, welding current, and electrode wire feeding speed according to an input signal.