JP2017170458A - Arc-welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the problem of this high frequency malfunction, due to being high in danger of the malfunction by a high frequency, since an arc-welding device for which a control signal cable is not used transmits information on an ON-OFF state of an output opening-closing switch by using a carrier wave of the high frequency.SOLUTION: Two cables are connected between a control device part provided near a welding power source and a control device part provided near a welding torch, and an auxiliary power source is provided in a control device provided near the welding power source, and an electric current is supplied to the control device part provided near the welding torch, and a size change in the electric current is different when an output switch is turned on and when the output switch is turned off. Welding output is turned on and off by detecting the size change in the electric current supplied from this auxiliary power source by a current detection element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an arc welding apparatus in which the number of signal lines of a signal cable connecting a welding power source and a control device side near a welding torch is reduced.

  The arc welding apparatus side of Patent Document 1 proposes means for reducing the number of control signal cables connecting the welding power source side and the control apparatus side near the welding torch.

In the prior invention, a welding output open / close signal is transmitted from a control device provided near a welding torch using a carrier wave to a welding power source using a welding current cable.

When the output switch is turned on, the output switch signal is superimposed on the carrier wave from the control device side provided near the welding torch to the welding power source side, and the output switch signal is transmitted using the welding current cable.

Patent Publication Showa 59-193765

  In the prior invention, the welding output switching signal is transmitted using a carrier wave. However, in this method, when there is a welding cable for an adjacent arc welding machine, the signals are electromagnetically coupled, and one welding output switching signal is There is a possibility of transferring to the welding cable of the other arc welder and causing the other arc welder to malfunction. It is an object of the present invention to eliminate the possibility of malfunction due to high frequency.

The arc welding apparatus of the present invention is provided with a control unit provided near a welding power source and a control unit near a welding torch connected to two cables and provided in a control unit provided near the welding power source. Power is supplied from the auxiliary power source to the control unit near the welding torch.

The magnitude of the current supplied from the auxiliary power source varies depending on the operating state of the solenoid valve and the consumable electrode feeding motor provided in the control unit near the welding torch. A change in the magnitude of this current is detected by a current detection element provided in a control unit near the welding power source to determine whether the output switch is turned on or off.

According to the present invention, since the operating state of the output switch is not judged using high frequency, there is no fear of malfunction due to electromagnetic coupling. In addition, since a welding current cable can be used for signal transmission, it is possible to reduce the number of control cables connecting the welding power source and the control device provided near the welding torch, and the work efficiency of arc welding work. Can be improved.

Configuration of arc welding apparatus of the present invention Time chart of output switching signal, auxiliary power supply current, welding output voltage of arc welding machine of the present invention

The control device provided near the welding power source and the control device provided near the welding torch are connected by two cables, and the output switch is provided in the control device provided near the welding torch. And a solenoid valve and a feeding motor are arranged.

When the output switch at the start of welding is turned on, the solenoid valve is turned on, and the post-feed motor after a certain time is turned on.

When the output switch at the end of welding is turned off, the feed motor is turned off first, and the solenoid valve is turned off after a certain period.

The magnitude of the flowing current differs between the solenoid valve and the feed motor. Therefore, the change in current between when the output switch is on and when it is off changes as shown in the time chart of the output switching signal, auxiliary power supply current, and welding output voltage of the arc welding machine of FIG. This current change is detected by a current detection element provided on the welding power source side to determine the operation state of the output switch.

  In FIG. 1, 1 is a main control element, 2 is an output terminal, 3 is a feed roller, 4 is a base material, 5 is a plus side cable, 6 is a minus side cable, 7 is a current-carrying part, 8 is a consumable electrode, 9 is a consumable electrode It is a feed motor. In the arc welding machine, current is supplied from the welding power source, an arc is generated between the consumable electrode and the base material sent by the feed motor, and the base metal and the 8 consumable electrode are melted by arc heat to form a metal. Are joined.

10 is an output switch, 11 is a feed motor control circuit, 12 is a solenoid valve, and 13 is a solenoid valve sequence circuit. 9 to 13 in the figure are built in the control unit provided in the vicinity of the welding power source A in the figure.

14 is an auxiliary power source, 15 is a current detection element, 16 is a binary comparator circuit, and 17 is a main control element drive circuit. In the figure, reference numerals 14 to 17 are built in the control unit near the B welding torch.

In the control unit provided near the welding power source in FIG. 1A, 14 auxiliary power sources, 15 current detection elements for detecting current from the auxiliary power source, and 16 binary comparators for determining the magnitude of the signal of the current detection device A circuit is provided, and changes in current supplied from 14 auxiliary power sources are detected by 15 current detection elements.

When the 9 feed motor is on, the output from the 16 binary comparator circuit will be larger than the second reference voltage. When the 12 solenoid valve is on, the 16 binary comparator circuit will Is larger than the signal of the first reference voltage.

When the output from the 16 binary comparator circuit becomes larger than the signal of the first reference voltage, the main control element 1 is turned on in the 17 main control element drive circuit, and the output from the 16 binary comparator circuit is When changing from a value greater than the second reference voltage to a value greater than the first reference voltage, a signal for turning off the main control element is given to the 17 main control element drive circuits after a certain period of time.

In the arc welding apparatus, in order to prevent welding defects at the start and end of welding, when the output switch at the start of welding 10 is turned on, gas flows first, and then 8 consumable electrodes are fed. This time is called preflow time.

At the end of welding, when 10 output switches are turned off, 8 consumable electrodes are turned off first, and then 12 solenoid valves for supplying gas are turned off. This time is called afterflow time.

In the present invention, a change in the current supplied from the auxiliary power source during the preflow time at the start of welding and a change in the current supplied from the auxiliary power source during the afterflow time at the end of welding are detected on the welding power source side. It is determined whether the output switch is turned on or off.

In the arc welding apparatus of the present invention, as shown in FIG. 1, a control unit provided near the welding power source unit A and a control unit near the welding torch B are connected by two cables to form a closed loop. doing.

Since the change in the current flowing in the closed loop is detected, the control device provided near the welding power source of A and the control device near the welding torch B connected by two cables are always paired. Works. Because it detects by the magnitude of the current, it always works only between the devices that make up the closed loop. Therefore, unlike the conventional signal transmission method using a carrier wave, there is no fear of high-frequency malfunction.

As shown in the time chart of the output switching signal, auxiliary power supply current, and welding output voltage of the arc welding machine of the present invention in FIG. 2, when pre-flowing, when 10 output switches are turned on, the current that drives 12 solenoid valves is It flows from 14 auxiliary power sources. This change in current is detected by 15 current detection elements provided in a control unit provided near the welding power source of A, and the output of the welding power source is turned on.

When the 10 output switches are turned off, the consumable electrode feeding motor stops and the afterflow starts, so the current supplied from the 14 auxiliary power supplies changes. This change in current is detected by 15 current detection elements provided in a control unit provided near the welding power source, and the output of the welding power source is turned off.

  According to this invention, since the number of control cables is reduced, an arc welder can be produced at low cost.

Since the number of control cables is reduced, the extension cable connecting the welding power source and the welding worker is lighter, and the burden on the worker can be greatly reduced at work sites where welding must be performed while moving over a wide range of work. In particular, it is expected to be used in arc welding equipment used in outdoor welding sites such as shipyards and construction sites.

A Control unit provided near the welding power source unit B Control unit near the welding torch 1 Main control element
2 Output terminal
3 Feed roller
4 Base material
5 Positive cable
6 Negative cable
7 Current-carrying part
8 Consumable electrodes
9 Feed motor
10 Output switch
11 Feed motor control circuit
12 Solenoid valve
13 Solenoid valve sequence circuit
14 Auxiliary power
15 Current detection element
16 Binary comparator circuit
17 Main control element drive circuit

Claims (3)

  The control device provided near the welding power source and the control device provided near the welding torch are connected with two cables, and the output is opened and closed in the control device provided near the previous welding torch. A solenoid motor, a solenoid valve, a feeder motor, a solenoid motor sequence circuit, and a feeder motor control circuit for controlling the feeder motor, and when the output switch is turned on, the solenoid valve is turned on, after a certain period of time The feed motor control circuit is configured to turn on the feed motor, and when the output switch is turned off, the feed motor is turned off first, and after a certain period of time, the solenoid valve sequence circuit A main control element for adjusting the output of the welding machine, a main control element drive circuit for the main control element, a control circuit provided near the welding power source, and a main control element drive circuit for the main control element, near the welding power source In the control unit provided in Auxiliary power supply that supplies power to the control unit provided near the initial welding torch, a current detection element that detects current from the previous auxiliary power supply, and the magnitude of the signal of the previous current detection element is the value of the first reference signal A binary comparator circuit is provided that turns on the output when the value is equal to or greater than that of the second reference signal and turns off the output when the value is equal to or less than the value of the second reference signal. An arc welding apparatus characterized in that when the signal becomes larger than the signal, a signal for turning on the main control element is given to the main control element drive circuit to turn on the welding output. When the magnitude of the signal of the current detection element becomes equal to or lower than the second reference voltage of the binary comparator circuit, a signal for turning off the main control element is sent from the binary comparator circuit to the main control element drive circuit after a certain time period. 2. The arc welding apparatus according to claim 1, wherein the welding output is turned off. 2. The welding current cable according to claim 1, wherein a welding current cable is used as the two cables that connect the control device provided near the welding power source and the control device provided near the welding torch. Arc welding equipment.

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