JPH04258375A - Arc welding power source - Google Patents

Abstract

PURPOSE:To easily and accurately set welding conditions and control welding work by storing welding data, in a card-shaped storage means and performing welding based on the data stored in this storage means. CONSTITUTION:The welding sequence determined by the welding conditions and the welding data such as numerical values in the welding sequence are stored in the card-shaped storage means such as an IC card. This IC card is inserted into a reading and writing device 60 and the stored welding data are read and transmitted to a MPU 43 of a control part. The MPU 43 outputs necessary signals according to these data and carries the welding sequence into execution. Accordingly, it is not necessary to carry out complicated setting prior to welding work and further, there is no possibility of erroneous setting or erroneous adjustment. Further, since a welding operator merely controls the IC card, work control is easily and surely carried out.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc welding power source that generates an appropriate arc between an electrode and a base material in arc welding.

0002

[Prior Art] As is well known in arc welding, TIG (
Tungsten Inert Gas) welding, M
AG (Metal Active Gas) welding,
MIG (Metal Inert Gas) welding,
There are welding methods such as CO2 welding. In such arc welding, as described above, an arc welding power source is used to generate an appropriate arc between the electrode and the base metal and to ensure that welding is performed without any problems. The configuration of the arc welding power source varies depending on the welding conditions such as the welding sequence, which is selected in consideration of the above-mentioned welding method and various other matters. Two examples of welding sequences will be described below with reference to FIGS. 4 and 5. FIG. 4 is a time chart of the basic operation sequence in TIG welding. In the figure, waveform a indicates ON/OFF of the torch switch, and waveform b indicates TIG.
The flow and cutoff of the shielding gas used for welding is shown in waveform c.
indicates the presence or absence of a high frequency voltage output, and waveform d indicates the arc current. In this example, the torch switch is a normal on/off switch and is pressed once (in the figure,
(indicated by ON), then release the switch (indicated by O in the figure).
FF), the switch is opened and the activation signal is held. Now, when the torch switch is turned on, the solenoid valve in the arc welding power source opens and the supply of shielding gas is started as shown in waveform b. After a sufficient time (preflow time) for this shielding gas to reach the torch located far from the arc welding power source, the waveform c
A high frequency voltage is applied between the electrode and the base material as shown in . Application of this high frequency voltage easily destroys the insulation between the two. When dielectric breakdown occurs and an arc occurs, the arc welding power source starts supplying arc current as shown in waveform d, and at the same time, high-frequency output is stopped. The arc current is initially suppressed to a low current value (starting current), which allows the worker to weld for a short time while avoiding melting and creating holes in the base material when the base material is thin. Observe the aspects of When the worker determines that welding is possible, he releases his hand from the torch switch. Thereafter, the arc current reaches the set normal welding current after a predetermined period (up slope time) has elapsed. The up slope time is a time for gradually increasing the arc current in order to prevent swelling that occurs at the welding location when the welding current is immediately changed from the start current. The welding current is a pulsed current having a predetermined pulse width and a base current as shown in the figure, and is controlled by an output control circuit (not shown) based on a current value detected by a current detector (not shown). To finish welding, the worker presses the torch switch again as shown in waveform a. At this time, the arc current is not immediately reduced to 0, but is gradually reduced for a certain period of time (downslope time), and then a constant low current value (crater current) is maintained until the worker releases the torch switch. It is set to 0. This is to prevent cavities and cracks from forming inside the welding area due to rapid cooling of the molten metal when the arc current is rapidly reduced to zero, and to minimize the dent (crater) that occurs at the welding end. This is the sequence used for After the torch switch is turned off,
Sufficient time for the final melt to cool down to a temperature where it is not affected by high temperature oxidation (afterflow time), waveform b
As shown in Figure 2, the supply of shielding gas continues to protect the melting section from nitrogen and hydrogen in the air. Figure 5 shows CO2
It is a time chart of a basic operation sequence in welding. In the figure, waveform a is the ON/OFF of the torch switch.
, waveform b is the shielding gas used for CO2 welding (
The waveform c shows the voltage applied between the wire electrode and the base material, and the waveform d shows the wire feeding speed of the wire electrode. The above-mentioned torch switch is not self-retaining, and the switch closes while the torch switch is pressed and opens when released. When the torch switch is turned on, shielding gas is immediately supplied as shown in waveform b, and after the preflow time has elapsed, the wire feeding speed is slowed down as shown in waveform d. Contact. On the other hand, at the same time as the wire feeding starts, a voltage is applied between the wire and the base metal by the arc welding power source, but this voltage is initially set to a high voltage (no-load voltage) as shown in waveform c, and the voltage is applied between the wire and the base metal. An arc is generated between the materials, and the voltage (starting voltage) is maintained at a voltage lower than the no-load voltage but sufficiently high. As a result, the wire is quickly melted in the low temperature state at the start of welding. Thereafter, the voltage is controlled to a predetermined welding voltage by the arc welding power source,
Further, the wire is controlled at a predetermined speed by a wire feeding control circuit provided separately. When welding is completed and the worker turns off the torch switch as shown in waveform a, the wire is fed out by an amount determined by the inertia of the motor, and then feeding is stopped. This state is shown by the downslope of waveform d. As shown in waveform c, the arc welding power source is operated for a sufficient time (
A gradually decreasing voltage is applied between the wire and the base material by the voltage delay time). On the other hand, as shown in waveform b, the shielding gas is supplied during the afterflow period for the same reason as in the case of TIG welding, and then the supply is cut off. The welding sequences under two different welding conditions have been illustrated above. However, there are many other welding conditions. For example, when performing pulse welding in MAG welding, a sequence that is a combination of the sequence shown in Fig. 4 and the sequence shown in Fig. 5 is adopted, and even in TIG welding, a sequence similar to that shown in Fig. 5 is adopted. Furthermore, various sequences are used, such as the sequence shown in FIG. 5 in which cratering processing is employed.

Next, a panel of an arc welding power source that executes the above sequence will be illustrated. FIG. 6 is a front view of a panel of an arc welding power source that performs TIG welding. In the figure, 1 is a panel, and 2 is an ammeter that displays the welding current. 3 to 9 indicate knobs on a setting device for setting predetermined numerical values;
The meaning of these numbers has already been explained. 10 is a setting knob that is determined according to the type of operation of the torch switch, etc. 11 and 12 are switches that are switched depending on whether the welding current is a pulsed current or not, and if it is a pulsed current, what is its frequency band; 13 is a switch that controls (adjusts) the solenoid valve that opens and closes the shielding gas; 14 is a switch for selecting the cooling method of the torch. FIG. 7 is a front view of a panel of an arc welding power source that performs CO2 welding and MAG welding. In the figure, 20 is the panel, 21
22 is an ammeter that displays the welding current, and a voltmeter that displays the welding voltage. Reference numeral 23 denotes a knob of a di/dt setting device, which sets the amount of current change di/dt according to welding conditions in order to electronically perform the function of the DC reactor. 24 to 28 are setting device knobs for setting the numerical values shown in the figure, respectively;
The meaning of each numerical value is as already stated. 29 indicates the presence or absence of crater control; 30 indicates the presence or absence of welding current pulse; 31
are switches that select whether or not to control the shield gas solenoid valve. The operator operates the knobs and switches on these panels to perform welding in the desired sequence.

0004

By the way, in order to accurately operate the knobs and switches on the panel of the arc welding power source during welding work, these knobs and switches are shown in FIG.
Since there are a large number of settings as shown in FIG. 7, it is not only extremely troublesome for the operator, but also often leads to incorrect settings. Further, even if the operator sets these knobs and switches correctly, the operator or another person's body may touch these knobs or switches during work and the setting conditions may change. Errors in settings that occur in this way can lead to various welding defects, such as solidification cracks when a crater is changed from "presence" to "absence," or when the pulse conditions are incorrect, the wire may not melt or vice versa. This may cause situations such as overmelting. When such welding defects occur, a lot of time and cost are required to repair them. Furthermore, since settings and adjustments using these knobs and switches are performed by the operator, the manager who has specified the required values based on the welding conditions will not be able to do so unless he or she actually goes to the welding site and checks these knobs and switches.
It is unclear whether the settings and adjustments were made correctly. Furthermore, the actual welding current and welding voltage may vary depending on the condition of the workpiece and the worker's construction method (for example, the distance between the torch and the base metal), so accurate data such as construction history and operating time cannot be obtained. Another problem was that it was difficult to manage the actual welding work. SUMMARY OF THE INVENTION An object of the present invention is to provide an arc welding power source that solves the problems of the prior art described above and allows easy and accurate setting of welding conditions and management of welding operations.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an arc welding power source that generates an appropriate arc between an electrode and a base material according to welding conditions. a card-shaped storage means for storing welding data stored in the storage means; a reading means for reading the welding data stored in the storage means; a control section for suppressing welding based on the welding data read by the reading means; A writing means for storing actual welding data during welding in the card-shaped storage means is provided.

[0006]

[Operation] The welding sequence determined by the welding conditions and the welding data such as numerical values during the welding sequence are stored in a card-shaped storage means, such as an IC card. This storage means is inserted into a reading and writing device to read the stored welding data and transmit it to the control section. The control section outputs a necessary signal in accordance with this, and executes the welding sequence. During welding, the actual welding data is sent to the IC at regular intervals.
Store it on the card.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. FIG. 1 is a block diagram of an arc welding power source according to an embodiment of the present invention. In the figure, 35 is a torch switch that commands starting and stopping the arc, 36 is an on-off switch for a solenoid valve 58 that controls opening and closing of the shield gas flow, 37 is an output setting device, and 38 is a fine adjustment device for the output setting device 37. be. The output setting device 37 sets the wire feeding speed and output voltage in the case of CO2=welding, for example, and sets the wire feeding speed and pulse period in the case of pulsed MAG welding, and in this case, the fine adjuster 38 Reference values such as pulse width and pulse period are increased or decreased in step 1, and furthermore, in the case of TIG welding, for example, pulse current and base current are set. In the case of this TIG welding, it is also possible to set a pulse current in the output setting device 37 and a base current in the fine adjuster 38. Reference numeral 39 denotes a display changeover switch for changing over the display displayed on the display device 59. 40 is an A/D converter that converts the values set in the output setter 37 and the fine adjuster 38 into digital values, and 41 is an input/output unit (I/O) for each signal. 43 is an MPU (microprocessor unit) that performs necessary calculations and controls based on input signals, 44 is a ROM (read-on memory) that stores the processing procedures of the MPU 43, and 45 is a RAM (random memory) that stores various data. access memory). 46 is an input/output section, and 47 is a D/A converter that converts signals obtained by calculation and control in the MPU 43 into analog values. A/D converter 40, input/output sections 41, 46, M
PU43, ROM44, RAM45, D/A converter 47
A microcomputer is configured. 48 is a base material, 49 is a wire electrode, 49W is a reel around which the wire electrode 49 is wound, 50 is a motor that sends the wire electrode 49 toward the base material 48, and 51 is a feed motor control that controls the speed of the motor 50. It is a circuit. A welding power source 52 supplies a voltage or current to the wire electrode 49 according to the value output by the MPU 43, and is equipped with a DC power source obtained by rectifying a commercial three-phase AC. 53 is a shunt that divides the welding current; 54
A current detector 55 detects the current of the shunt 53 and outputs a signal proportional to the welding current, and a voltage detector 55 detects the output voltage and outputs a signal proportional to the welding voltage. 56,
57 are subtracters, and feedback control is performed by subtracting the output values of the current detector 54 and voltage detector 55 from the command value output from the D/A converter 47. Note that the feedback control of both the subtracters 56 and 57 is not used at the same time, but only one of them is used. The type of feedback control to be used is determined by the welding method. For example, constant voltage characteristics are used for CO2 welding and MAG welding, so voltage feedback control is used, and constant current control is used for pulsed MAG welding, TIG welding, etc. Since the characteristic is used, current feedback control is adopted. 60 is an IC card reading and writing device. In this embodiment, welding sequences and various welding data during welding are stored in an IC card for each welding condition, and these data are read by an IC card reading and writing device 60. Further, as will be described later, data in the ROM 44 is written to the IC card by an IC card reading and writing device. The welding data read by the IC card reading and writing device 60 is output to the MPU 43 via the input/output section 41. The display device 59 displays data such as the sequence stored in the IC card, the output voltage set by the output setting device 37, the wire feeding speed, etc., and the display is sequentially switched and displayed by the display changeover switch 39. Ru. FIG. 2 is a front view of a panel of the arc welding power source shown in FIG. 1. In the figure, parts that are the same as those shown in FIGS. 1 and 7 are designated by the same reference numerals, and explanations thereof will be omitted. Reference numeral 61 indicates an IC card insertion slot into which an IC card storing welding sequences, welding data, etc. is inserted. The panel of this embodiment has a much simpler structure than the conventional panels shown in FIGS. 6 and 7.

Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG. Depending on the welding work scheduled to be performed, the manager selects an IC card storing the best welding data for the welding work, and hands this IC card to the worker. The worker holds the handed IC card and turns on the arc welding power source (step S1 in the flowchart shown in FIG. 3). As a result, initialization of the arc welding power source shown in Fig. 1 is executed (step S2), and RO
A data check of M44 and RAM 45 is performed (step S3). If there is no abnormality in the data check, the worker inserts the IC card received from the administrator into the IC card insertion slot 61 (step S4). The IC card reading and writing device 60 reads welding data from the inserted IC card. MPU43 stores the read welding data in RAM.
45 (step S5). Although this data transfer is not necessarily necessary, it is transferred to the RAM 45 in order to prevent malfunctions due to high frequencies generated during welding. During welding, this transferred data is used for control and for the IC card reading and writing device 60. Connection with MPU43 is O
It is desirable to set it to FF. The welding data on the IC card is first checked on the display device 59 (step S6).
). If there is an abnormality in the data, it is checked whether the correct IC card is being used (step S7), and if the IC card is incorrect, the correct IC card is replaced. If the data on the IC card is correct, then the data transferred to the RAM 45 is checked. Next, set the output such as wire feeding speed, voltage, current, pulse period, etc. (
Step S8): This setting is performed by specifying a predetermined address in the RAM 45 and using remote control. Thus,
Ready for arc welding. The MPU 43 monitors whether or not the torch switch is turned on (step S9), and when the operator turns on the torch switch to start welding, it recognizes the output of this start signal and executes the arc start sequence. (Step S10). Then, when the start current is detected (step S11)
, the process moves to step S12, and an output control program for main welding is executed. During this time, the MPU 43 checks the presence or absence of a stop signal from the torch switch (step S13), and if no stop signal is output, current detection is performed in step S11. By this current detection, if a long arc break occurs during main welding, it is detected, and the process returns to the arc start program again. If there is no arc breakage or if there is arc breakage but it is short, the output control program is executed as is. During this time, the welding current and voltage during arc generation are D/
The data is input to the MPU 43 via the A converter 47 and the I/O 46, and is stored in the ROM 44 at regular intervals. At the same time, the arc occurrence time is also stored. When a welding stop signal is output from the torch switch, the process moves to step S14, and an arc stop program (afterflow, etc.) is executed. This arc stop program includes the RO
The arc time, welding current, and voltage data stored in M44 are transferred to i/o41 and IC card reading and writing device 6.
It consists of a program that is written and stored in an IC card via 0. Welding ends when this arc stop program ends. Next, it is determined whether or not to continue welding work (step S15), and if there is no further welding work, the IC card is taken out from the IC card insertion slot 61 (step S16), and the power is turned off (step S15). S17). Procedure S
When it is determined that welding work is to be performed successively in step S15, it is determined whether the subsequent welding work is performed under the same conditions (step S18), and if the welding work is not under the same conditions,
The output setting work in step S8 is performed, and thereafter steps up to step S14 are performed. Furthermore, if the welding work is performed under the same conditions, the torch switch is turned ON and the work from step S9 to step S14 is performed. In this way, in this embodiment, the welding data is stored in the IC card and the welding work is performed based on this.
There is no need to make complicated settings prior to welding work, and
There is no risk of incorrect settings or adjustments. Furthermore, since the welding manager only has to manage the IC card, work management becomes easy and reliable. Furthermore, the configuration of the front panel of the arc welding power source can be extremely simplified. Furthermore, since the welding current, voltage conditions, and arc time during welding are stored in the IC card, actual work conditions can be managed by checking these. In addition, in the explanation of the above embodiment, the configuration for CO2 welding was mainly illustrated, but for example, a TIG welding power source can be configured by using a high frequency generation circuit in place of the feed motor control circuit shown in FIG. With such simple changes, it is possible to adapt to various welding methods. Also, although we have shown an example of installing an ammeter and a voltmeter on the panel,
Since there is almost no need to check the setting conditions etc. during welding, if the configuration is such that the welding current and welding voltage are displayed on the display device using current and voltage detection signals, the ammeter and voltmeter can be omitted. Can be done.

[0009]

As described above, in the present invention, welding data is stored in a card-like storage means, and welding is performed based on the data stored in this storage means, so that welding conditions can be set. is easy and accurate. Further, the welding manager can reliably manage the work by managing the storage means. At the same time, the actual welding current, welding voltage and arc time can be memorized, allowing accurate data such as welding history and operating time to be obtained.By checking these, work management can be performed more reliably. Can be done. Furthermore, since the configuration of the front panel of the arc welding power source is almost the same even if the welding method is different, there is no need to design the front panel for each model. Furthermore, the configuration of the front panel can be extremely simplified, contributing to downsizing of the arc welding power source.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an arc welding power source according to an embodiment of the present invention.

FIG. 2 is a front view of a panel of the arc welding power source shown in FIG. 1.

FIG. 3 is a flowchart illustrating the operation of the arc welding power source shown in FIG. 1;

FIG. 4 is a time chart of a welding sequence.

FIG. 5 is a time chart of a welding sequence.

FIG. 6 is a front view of a panel of a conventional arc welding power source.

FIG. 7 is a front view of a panel of a conventional arc welding power source.

[Explanation of symbols]

43 MPU 44 ROM 45 RAM 48 Base material 49 Wire electrode 51 Feeding motor control circuit 59 Display device 60 IC card reading and writing device 61 IC card insertion slot

Claims (2)

[Claims] 1. An arc welding power source that generates an appropriate arc between an electrode and a base metal according to welding conditions, comprising: a card-shaped storage means for storing welding data specified by the welding conditions; a reading means for reading the welding data stored in the means; a control section for controlling welding based on the welding data read by the reading means; and storing actual welding data during actual welding in the card-shaped storage means. An arc welding power source characterized by being provided with a writing means for writing. 2. The arc welding power source according to claim 1, wherein the welding data includes at least a welding sequence and predetermined welding condition data.