JP2011156590A - Welding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that self-shielded arc welding requires a large generator using alternating current in general, and at a place where a large generator is unavailable, arc welding is carried out with the use of a welder or self-shielded arc welding is carried out with a large generator provided separately. <P>SOLUTION: In the invented welding method, when alternating current is unavailable, direct-current arc welding is performed using a DC/AC source such as an engine welder. The welding method requires no large generator, improves economic efficiency and enables welding in a narrow space. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a welding method for performing self-shielded arc welding using a direct current, and more particularly to a welding method capable of using an engine welder as a power supply device by changing a welding current applied to self-shielded arc welding to a direct current. Is.

  Conventionally, in order to perform self-shielded arc welding, as described in Patent Document 1 and Patent Document 2, a large AC welder is used as a power supply device. Even when performing self-shielded arc welding outdoors, it is necessary to use a large AC welding machine. That is, the primary power source generated by the AC welding machine is supplied to the no-gas automatic welding machine through the cap tire to perform self-shielded arc welding.

  For example, as shown in FIG. 3, a commercial frequency AC 200V power source is applied to an AC welding machine (main transformer) 101 and self-shielded arc welding is performed using a no-gas automatic welding machine 102. In the no-gas automatic welding machine 102, the reference voltage circuit 103 determines the rotation speed of the wire feed motor 105 via the motor circuit 104. The motor circuit 104 is a circuit for applying a voltage to the wire feed motor 105, and is configured to make the motor current flow different between welding and inching. The motor voltage comparison circuit 106 is a circuit that operates the pulse generation circuit 107 by comparing the reference voltage set by the motor output command circuit 108 with the induced voltage. The pulse generation circuit 107 is an oscillation circuit configured by a combination of a transistor, a capacitor, and a transformer, and is a circuit that generates a pulse in the transformer and supplies a pulse to the gate of the thyristor to turn on the thyristor. The voltage detection circuit 109 is a circuit that drives the wire feed motor 105 by turning on the relay when a welding current flows and supplying an arc current to the wire feed motor 105.

JP 2000-202629 A JP-A-8-1351

  By the way, in the prior art mentioned above, since it is necessary to use a large-sized AC welding machine as a power supply device, it is not easy to perform welding outdoors, narrow places, and high places.

  Therefore, the present invention has been proposed in view of the above-described circumstances, and can perform self-shielded arc welding with a no-gas automatic welding machine using a DC / AC power source such as an engine welder, and can be used outdoors or in narrow spaces. An object of the present invention is to provide a welding method that facilitates welding at a high place.

  In order to solve the above-described problems and achieve the object, a welding method according to the present invention has the following configuration.

[Configuration 1]
A DC AC power supply is used to supply a DC high voltage power supply for welding to a DC current machine welding machine, the AC voltage from the DC AC power supply is reduced to a low voltage by a transformer, and the operation AC power supply is welded. The wire is fed by operating the machine, and self-shielded arc welding is performed by a DC high voltage power supply for welding.

  In the welding method according to the present invention, since a direct current AC power source such as an engine welder is used in self-shielded arc welding, a large alternating current welder (generator) is not required, and because of the direct current characteristics, the period is Therefore, the welded portion can be efficiently and continuously heated, the welding time can be shortened, and welding can be performed stably.

  That is, the present invention provides a welding method capable of performing self-shielded arc welding with a no-gas automatic welding machine using a DC / AC power source such as an engine welder, and facilitating welding outdoors, in narrow places, and in high places. It is something that can be done.

It is a side view which shows the structure of the welding apparatus for enforcing the welding method which concerns on this invention. It is a block diagram which shows the structure of the welding apparatus for enforcing the welding method which concerns on this invention. It is a block diagram which shows the structure of the conventional welding apparatus.

  Hereinafter, embodiments of a welding method according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side view showing a configuration of a welding apparatus for carrying out a welding method according to the present invention.

  In order to carry out the welding method according to the present invention, as shown in FIG. 1, an engine welder 1 that is a DC / AC power source equipped with a power source and a power source device and a welding machine main body 3 are used. As the engine welder 1, for example, it is possible to use a 1t car or a set in an exclusive small mobile device.

  The engine welder 1 supplies operation AC power to the welding machine main body (no gas automatic welding machine) 3 via the transformer 2 and the control cable 11. Further, the engine welder 1 supplies a welding DC high-voltage power supply to the welding machine main body 3 and the base material 9 via the welding cable 6. The welder body 3 is connected to the base material 9 by a single core cap tire cable 10.

  The welding machine main body 3 includes a control device 4 and a wire supply device 5. The welding machine body 3 supplies the flexible conduit 7 to the welding torch 8 by the wire supply device 5.

  In this welding method, the welding machine main body 3 is operated by an AC power source for operation, and self-shielded arc welding is performed by a DC high voltage power source for welding.

  FIG. 2 is a block diagram showing a configuration of a welding apparatus for carrying out the welding method according to the present invention.

  As shown in FIG. 2, the engine welder 1 has a built-in generator composed of a rotor 12 and a stator 13, and outputs an alternating current power source A (rated 200 V, 43.3 A) and direct current through a rectifier 14. Power supplies B (+) and B (−) (rated 34V, 350A) are output.

  The AC power source A is supplied to the welding machine main body 3 through the transformer 2 as an AC power source for operation (30 V). Further, the DC power supplies B (+) and B (−) are supplied to the welding machine body 3 as welding DC high-voltage power supplies.

  In the welding machine main body 3, the reference voltage circuit 15 is supplied with the operation AC power source A, and determines the rotation speed of the wire feeding motor 17 of the wire supply device 5 via the motor circuit 16. The motor circuit 16 is a circuit for applying a voltage to the wire feed motor 17 and is configured to vary the way the motor current flows between welding and inching.

  The motor voltage comparison circuit 18 is a circuit that operates the pulse generation circuit 20 by comparing the reference voltage set by the motor output command circuit 19 with the induced voltage. The pulse generation circuit 20 is an oscillation circuit configured by a combination of a transistor, a capacitor, and a transformer. The pulse generation circuit 20 generates a pulse in the transformer, supplies a pulse to the gate of the thyristor, and turns on the thyristor.

  The voltage detection circuit 21 is supplied with the welding DC high-voltage power supply B (−) to turn on the relay, and supplies the wire feed motor 17 with an arc current. In the current detection circuit 22, a welding DC high-voltage power supply B (+) is supplied, and an arc voltage is applied to the relay.

  At the time of inching, a DC voltage obtained by rectifying the voltage passed through the transformer 2 by a diode is applied, and at the time of welding, a motor start relay works to apply the secondary voltage B (+) of the welding DC high-voltage power supply. Next, a constant voltage corresponding to the welding condition is applied to the motor output command circuit 19 through the welding current selection switch 23 and the Zener diode. The reference voltage circuit 15 turns the transistor ON / OFF in comparison with the motor induced voltage, and generates a pulse by the pulse generation circuit 20, thereby turning on the thyristor and driving the wire feed motor 17.

  The wire supply device 5 and the motor output command circuit 19 may be housed in a carriage separated from the welding machine body 3. This carriage is connected to the welding machine main body 3 by a power transmission cable and a signal cable, and is lightweight and easy to carry. In this case, it is only necessary to carry the welding machine body 3 in the vicinity of the place where welding is performed while the main body 3 is installed at a position away from the place where welding is performed. Can be easily performed.

  As for the welding carried out according to the present invention, the durability time confirmation by the change of the voltage of the engine welder, the ultrasonic flaw detection test, the radiation flaw detection test, the dye flaw detection test, and the bending test are performed. It was confirmed that it was possible to do.

  The present invention relates to a welding method for performing self-shielded arc welding using a direct current, and to a welding method capable of using an engine welder as a power supply device by changing the welding current applied to the self-shielded arc welding to a direct current. Applied. This welding method is effective and economical particularly in a place where a large generator is not always available.

DESCRIPTION OF SYMBOLS 1 Engine welder 2 Transformer 3 Welding machine main body 4 Control apparatus 5 Wire supply apparatus 6 Welding cable 7 Flexible conduit 8 Welding torch 9 Base material 10 Single core cap tire cable 11 Control cable

Claims (1)

Using a direct current alternating current power supply, a direct current high voltage power supply is supplied to a direct current machine welding machine, and the alternating current voltage from the direct current alternating current power supply is reduced to a low voltage by a transformer to be an operational alternating current power supply.
A welding method comprising operating a welding machine with the AC power source for operation to perform wire feeding, and performing self-shielded arc welding with the DC high-voltage power source for welding.

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