JP2005095907A - Inverter control type arc welding power device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter control type arc welding power device of a simple structure adaptable to a plurality of AC voltage values of a commercial power supply. <P>SOLUTION: An automatic transformer 50 has at least three terminals in each of windings u, v and w and selects terminals U1-U8, V1-V8 and W1-W8 to input the commercial power supply 1, and fixes the terminals connected to the input side of a main circuit A to any one of them. The commercial power supply 1 is connected to any one of the terminals U1-U8, V1-V8 and W1-W8 to the high current-voltage value. Winding to drive a control circuit is preferably provided in parallel to winding of the auto-transformer 50. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention converts an AC voltage input from a commercial power source into a DC voltage, then converts it again to an AC voltage, converts it to a voltage suitable for welding by a transformer, and outputs it to the welded portion. The present invention relates to an arc welding power source apparatus.

  FIG. 4 is a configuration diagram of a conventional inverter-controlled arc welding power supply device.

  The AC voltage supplied from the commercial power source 1 is rectified to a smooth DC voltage by an AC / DC converter circuit 5 including a rectifier circuit 3 and a smoothing capacitor 4 via a switch 2, and converted to a high frequency AC voltage by an inverter circuit 6. It is converted and supplied to the transformer 7. Then, the voltage is reduced to a voltage suitable for welding by the transformer 7, supplied to the rectifier unit 8, and output between the external output terminals 10 and 11 via the reactor 9.

  A welding wire 13 and a base material 14 are connected to the output terminals 10 and 11 via contact tips 12, respectively, and an arc 15 is generated between the welding wire 13 and the base material 15 during welding.

  The control transformer 20 supplies power to a control circuit 21 that controls the inverter circuit 6 and the motor drive circuit 22. The control transformer 23 supplies power to the motor drive circuit 22 that drives the motor 25. The motor 25 is supplied with electric power via the connection terminal 24 and supplies the wire 13 to the welded portion.

  In addition, although illustration is abbreviate | omitted, another inverter circuit is arrange | positioned between the rectifier part 8 and the output terminals 10 and 11, and it is an inverter control type | formula comprised so that alternating current power might be supplied between the output terminals 10 and 11 There is also an arc welding power supply. Hereinafter, the circuit from the AC / DC conversion circuit 5 to the output terminals 10 and 11 is referred to as “main circuit A”.

  The main circuit A and the control transformers 20 and 23 are accommodated in a housing 30 indicated by a dotted line. Note that the switch 2 may be disposed inside the housing 30 or disposed outside the housing 30.

  By the way, AC voltage values of the commercial power source 1 include 200V, 220V, 230V, 380V, 400V, 440V, and 480V.

  The number of turns of the input side winding of the transformer 7 employed in the inverter-controlled arc welding power source is several turns. For this reason, a transformer 7 is prepared for each AC voltage value of the commercial power source 1. Further, the elements constituting the inverter circuit 6 and the rectifier circuit 3 and the control transformers 20 and 23 are also prepared according to the AC voltage value of the commercial power source 1.

  However, if it does in this way, an arc welding power supply device must be prepared for every alternating voltage value of commercial power supply 1, and a model increases.

Therefore, two sets of inverters 6 are provided on the output side of the AC / DC conversion circuit 5 and two windings on the input side of the transformer 7 are used, so that even if the input voltage is 1: 2 (for example, 460V and 230V), one unit can handle it. There is also an arc welding power supply device that can be used (Patent Document 1).
JP 2001-162369 A

  However, in the arc welding power supply device disclosed in Patent Document 1, when the input voltage is 440 v / 220 V or 400 v / 200 V, for example, separate devices must be prepared. For this reason, it cannot be said that the number of models greatly decreases. In addition, the device structure has become complicated.

  An object of the present invention is to provide an inverter-controlled arc welding power supply apparatus that solves the above-described problems in the prior art, has a simple structure, and can cope with a plurality of AC voltage values of a commercial power supply.

  In order to solve the above-described problems, the present invention includes a main circuit including an AC / DC converter, an inverter, a transformer, and an output circuit unit, and converts an AC voltage input from a commercial power source into a DC voltage by the AC / DC converter. The inverter-controlled arc in which the DC voltage is converted into an AC voltage by the inverter, converted to a voltage suitable for welding by the transformer, and electric power is output to the welded portion through the output circuit unit. In the welding power source apparatus, the terminal connected to the input side of the main circuit is provided with a single-winding transformer having three or more terminals in one winding so that the terminal for inputting the commercial power can be selected. It is characterized by fixing.

  Since a single-winding transformer having three or more terminals is provided in one winding and the terminal for inputting the commercial power supply can be selected and the terminal connected to the input side of the main circuit is fixed, the commercial power supply AC Even when the voltage values are different, welding can be performed with a single inverter-controlled arc welding power supply. Further, since the types of parts are reduced, maintenance management becomes easy. Furthermore, the manufacturing time of the device can be shortened and the number of devices in stock can be reduced.

  Hereinafter, the present invention will be described based on illustrated embodiments.

  FIG. 1 is a connection diagram of an inverter-controlled arc welding power source apparatus according to the present invention. Components having the same or the same functions as those in FIG.

  In the figure, terminals (taps) U1 to U8 are provided on the U-phase winding u of the single-winding transformer 50. Here, the terminal U1 is one end of the winding u, and the terminal U8 is the other end of the winding u. When a voltage of 480V is input between the terminal U1 and the terminal U8, the terminal U2 is a position where the voltage difference from the terminal U1 is 200V, the terminal U3 is a position where the voltage difference from the terminal U1 is 220V, a terminal U4 is a position where the voltage difference from the terminal U1 is 230V, terminal U5 is a position where the voltage difference from the terminal U1 is 380V, terminal U6 is a position where the voltage difference from the terminal U1 is 400V, and terminal U7 is a position where the voltage difference is from the terminal U1. Are respectively arranged at positions where the voltage difference becomes 440V.

  The V-phase winding v and the W-phase winding w of the single-winding transformer 50 are also provided with terminals V1 to V8 and terminals W1 to W8 having the same relationship as the terminals U1 to U8 in the case of the winding u. It has been. The terminals V1 and W1 are connected to the terminal U1.

  Further, a winding 51 for supplying power to the control circuit 21 in parallel with the winding u of the single-winding transformer 50, and a winding for supplying power to the wire feed motor drive circuit 22 in parallel with the winding v. 52 are respectively arranged. The windings 51 and 52 are insulated from the windings u and v, respectively. Since the turns 51 of the windings 51 and 52 are the same, if the commercial power source 1 is connected to the terminals U1 to U8 corresponding to the voltage, the input voltage of the control circuit 21 and the wire feed motor drive circuit 22 Will always be the same.

  The inverter-controlled arc welding power supply apparatus configured as described above can be used by connecting a commercial power supply to any one of terminals U1 to U8, V1 to V8, and W1 to W8 corresponding to the AC voltage value. That is, when the AC voltage value of the commercial power source 1 is 440 V, the U phase of the commercial power source 1 is connected to the terminal U7, the V phase is connected to the terminal V7, and the W phase is connected to the terminal W7, respectively. Then, the terminals U2, V2, and W2 are connected to the main circuit A.

  In this case, since the input voltage of the main circuit A is the same regardless of the AC voltage value of the commercial power supply, the number of maintenance parts as a device is reduced, and maintenance management is facilitated. Furthermore, since the windings 51 and 52 are provided, it is not necessary to provide a control transformer for the control circuit, so that an increase in the price of the entire apparatus can be suppressed.

  Since the capacity of the control circuit power source constituted by the windings 51 and 52 is negligibly small, for example, when the capacity of the welding power source is 18 kVA and the usage rate is 60%, the approximate capacity Q of the single-winding transformer 50 is It is represented by Formula 1.

  Q = 18 kVA × (480−200) /480×0.6=6.3 kVA Equation 1

  FIGS. 2 and 3 are other connection diagrams of the inverter-controlled arc welding power supply according to the present invention. The same or the same functions as those in FIGS. Omitted.

  In general, the weight of the transformer is approximately proportional to the capacity. Therefore, if the single-winding transformer 50 is configured so as to be compatible with all commercial power supply AC voltage values as described above, the weight increases.

  Therefore, as shown in FIG. 2, the single-winding transformer 50 includes two types: a single-winding transformer 50a corresponding to an AC voltage value of 200V to 230V of the commercial power supply and a single-winding transformer 50b corresponding to 380 to 480V.

  In this way, the approximate capacity Qa of the single-winding transformer 50a and the approximate capacity Qb of the single-winding transformer 50b are expressed by equations 2 and 3.

Qa = 18 kVA × (230−200) /230×0.6=1.4 kVA ·· Equation 2
Qb = 18 kVA × (480-380) /480×0.6=2.3 kVA ·· Equation 3
As is apparent from the results of Equations 2 and 3, it is possible to make the approximate capacity of the single-winding transformers 50a and 50b, that is, the weight 1/4 to 1/3 that of the single-winding transformer 50, and increase the weight of the entire device Can be reduced. Also, the price is not so expensive.

  Therefore, it is practical to provide two types of single-winding transformers according to the AC voltage of the commercial power supply.

  In addition, what can be used for 400V is employ | adopted as the component of the main circuit A shown in FIG.

  Moreover, although the terminal for 220V and 230V was provided separately in the said FIG. 1, FIG. 2, you may make it share for 220 / 230V.

  1 and 3, the terminals for 380V and 400V are provided separately, but they may be shared for 380 / 400V.

  In addition, when there is an AC voltage value other than the above as the AC voltage value of the commercial power supply, a terminal corresponding to the voltage value may be provided.

  Furthermore, since the single-winding transformer according to the present invention can be applied regardless of the type of welding machine as long as the capacity is matched, standardization is easy. And when mass production becomes possible, manufacturing cost can be further reduced.

  In the above description, the case of a three-phase power source has been described. However, the present invention can also be applied to a case of a single-phase power source.

1 is a connection diagram of an inverter-controlled arc welding power supply device according to the present invention. FIG. 6 is a connection diagram of another inverter-controlled arc welding power supply according to the present invention. FIG. 6 is a connection diagram of another inverter-controlled arc welding power supply according to the present invention. It is a connection diagram of a conventional inverter-controlled arc welding power supply device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Commercial power supply 50 Single-winding transformer A Main circuit U1-U8 terminal V1-V8 terminal W1-W8 terminal u Winding v Winding w Winding

Claims (3)

A main circuit comprising an AC / DC converter, an inverter, a transformer, and an output circuit unit is provided. An AC voltage input from a commercial power source is converted into a DC voltage by the AC / DC converter, and the DC voltage is converted into an AC voltage by the inverter. After that, in the inverter control type arc welding power supply device, which is converted to a voltage suitable for welding by the transformer, and is output to the welding part through the output circuit part.
A single-winding transformer having three or more terminals is provided in one winding, the terminal for inputting the commercial power supply can be selected, and the terminal connected to the input side of the main circuit is fixed. Inverter-controlled arc welding power supply.   The inverter-controlled arc welding power supply device according to claim 1, wherein an output winding for control is provided on the single-winding transformer. The inverter-controlled arc welding power supply device according to claim 1 or 2, wherein the single-winding transformer and the main circuit are housed in a single casing.

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