JP2005254274A - Consumable electrode type alternating current arc welder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a consumable electrode type A.C. arc welder which supplies stable arcs. <P>SOLUTION: The invented consumable electrode type A.C. arc welder is equipped with a current detector 11 which judges arc extinction when on-off signal of the current detector is 'off', an arc/short circuit determining device 8 which determines arc or short circuit, and a conjunction circuit 12 which executes the conjunction of the output signals from the current detector 11 and the arc/short circuit determining device 8. This arrangement executes the conjunction of the output signals from the current detector 11 and the arc/short circuit determining device 8 so as to perform straight polarity/reversed polarity output control. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a consumable electrode type AC arc welder that alternately and repeatedly switches the polarity of a welding output applied between a consumable electrode and a base material between positive polarity and reverse polarity.

  In recent years, consumable electrode AC arc welders that can control heat input to a base metal and are suitable for the field of thin plate welding have been widely used particularly for aluminum welding.

  Conventionally, as this consumable electrode type AC arc welding machine, there has been one that maintains the output polarity without reversing when a short circuit occurs (see, for example, Patent Document 1).

  FIG. 3 shows a conventional consumable electrode type AC arc welder, in which 101 is an input AC power source, 102 is a welding output unit that converts the input AC power source 101 into an appropriate welding output, and 103 is an output side of the welding output unit 102. The first switching element for EP (reverse polarity) output arranged in the first switching element, 104 is the second switching element for EN (positive polarity) output arranged in series with the first switching element 103 on the output side of the welding output unit 102, 105 Is a consumable electrode connected to the connection point of the first switching element 103 and the second switching element 104, 106 is a base material connected to the output of the welding output section 102, and 107 is a voltage detection connected between the consumable electrode 105 and the base material 106. , 108 is an arc / short-circuit determining unit for inputting a signal from the voltage detector 107, 109 is a positive / reverse polarity adjuster, and 110 is a positive / reverse polarity adjuster 109. A positive polarity / reverse polarity output controller 111 for inputting these signals and a delay circuit 111 for inputting a signal from the arc / short-circuit determining unit 108 and outputting a signal to the positive polarity / reverse polarity output controller 110 for positive polarity. The reverse polarity output controller 110 is configured to output drive control signals for the first switching element 103 and the second switching element 104.

  The operation of the consumable electrode type AC arc welder configured as described above will be described with reference to FIG.

When the output signal of the positive polarity / reverse polarity adjuster 109 is EN (positive polarity) output, and when the S signal output is a short circuit of the A / S signal from the arc / short circuit determination unit 108, the S signal becomes an A signal. Until the EN / EP signal of the positive polarity / reverse polarity adjuster 109 changes to an EP (reverse polarity) output instruction, the output of the positive polarity / reverse polarity output controller 110 maintains the EN (positive polarity) output and polarity. Do not invert. Although not shown in the figure, the same operation is performed even when EP (reverse polarity) is output, and when the output signal of the positive polarity / reverse polarity adjuster 109 outputs EP (reverse polarity), A from the arc / short-circuit determination unit 108 is output. Even if the EN / EP signal of the positive polarity / reverse polarity adjuster 109 changes to the EN (positive polarity) output instruction until the short circuit is released when the S signal becomes an A signal when the S signal is output in which the / S signal is a short circuit, The output of the polarity / reverse polarity output controller 110 maintains the EP (reverse polarity) output and does not reverse the polarity.
Japanese Patent Laid-Open No. 11-156541 (paragraph number 0008, FIGS. 3 and 5)

  However, the conventional consumable electrode type AC arc welding machine is controlled to maintain the positive polarity when a short circuit occurs, especially on the positive output side where the arc is likely to be unstable. In the meantime, there is a high possibility that a failure such as arc breakage will occur, and since the polarity output control is not particularly performed at the time of the arc breakage, there is a problem that arc breakage is sustained and an arc failure occurs.

  It is an object of the present invention to provide a consumable electrode type AC arc welder that stably supplies an arc.

  In order to solve the above-mentioned problems, a consumable electrode type AC arc welder of the present invention includes a voltage detector connected between a consumable electrode and a base material for detecting a welding output voltage, and a welding output current connected in series to a welding output circuit. A current detector for detecting a current, an arc / short-circuit judging device for judging whether an arc or a short-circuit is detected based on a detection value of the voltage detector, a positive polarity / reverse polarity regulator for adjusting a welding output polarity ratio, A logic circuit that performs a logical product of the output signal of the arc / short-circuit detector and the output signal of the current detector, and the positive / reverse polarity output is controlled by the output signal of the positive / reverse polarity adjuster and the output signal of the logic circuit. A positive polarity / reverse polarity controller is provided.

  With this configuration, it is possible to control the positive polarity / reverse polarity output control by performing a logical product of the output signals of the current detector and the arc / short circuit determination device.

  As described above, the present invention stably supplies an arc by maintaining and switching the welding output to a reverse polarity in which the arc is stable when a short circuit occurs and an arc break occurs, based on the output signals of the arc / short circuit determination device and the current detector. can do.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  In FIG. 1, 1 is an input AC power source, 2 is a welding output unit that converts the input AC power source 1 into an appropriate welding output, and 3 is a first EP (reverse polarity) output arranged on the output side of the welding output unit 2. The switching element 4 is a second switching element for EN (positive polarity) output arranged in series with the first switching element 3 on the output side of the welding output portion 2, and 5 is the first switching element 3 and the second switching element 4. A consumable electrode connected to the connection point, 6 is a base material connected to the output of the welding output section 2, 7 is a voltage detector connected between the consumable electrode 5 and the base material 6, and 8 is a signal input from the voltage detector 7. Arc / short-circuit determination device 9, positive polarity / reverse polarity adjuster 9, positive polarity / reverse polarity output controller 10 for inputting a signal from the positive polarity / reverse polarity adjuster 9, and welding output unit 2 and mother ON / OFF detection of current detection (CD) provided between the materials 6 The current detector 12 performs a logical product of the output signal A / S signal of the arc / short-circuit determination device 8 and the output signal CD-ON / OFF signal of the current detector 11 and sends a signal to the positive / reverse polarity output controller 10. In the output AND circuit, the positive / reverse polarity output controller 10 is configured to output drive control signals for the first switching element 3 and the second switching element 4.

  The operation of the consumable electrode type AC arc welder configured as described above will be described with reference to FIG.

  When the output signal of the positive polarity / reverse polarity adjuster 9 is EN (positive polarity) output, when the S signal is output, the A / S signal from the arc / short-circuit determination device 8 is short-circuited, the S signal becomes the A signal. Until, the logical product of the output signal A / S signal of the arc / short-circuit determination unit 8 and the output signal CD-ON / OFF signal of the current detector 11 regardless of the EN / EP signal output of the positive polarity / reverse polarity adjuster 9 The polarity is changed to the reverse polarity output by the output of the logical product circuit 12 performing the above.

  Further, when the output signal of the positive polarity / reverse polarity adjuster 9 is EN (positive polarity) output, the output signal CD-ON / OFF signal of the current detector 11 for determining arc break is CD when the OFF signal indicating arc break is output. The output signal A / S signal of the ARCS short-circuit determination unit 8 and the output signal CD of the current detector 11 regardless of the EN / EP signal output of the positive polarity / reverse polarity adjuster 9 until the arc regeneration when the OFF signal becomes the ON signal. The polarity is changed to the reverse polarity output by the output of the logical product circuit 12 that performs the logical product of the ON / OFF signals.

  Although not shown, when the output signal of the positive polarity / reverse polarity adjuster 9 is EP (reverse polarity) output, the reverse polarity output is maintained.

  As described above, according to the present embodiment, the output signal CD-ON / OFF of the output signal, the A / S signal, and the current detector 11 that determines the arc breakage are determined. An arc can be stably supplied by controlling the reverse-polarity output that always has an arc stable polarity when an AND circuit 12 that performs an AND operation with a signal always causes an arc instability such as a short circuit or an arc break.

  According to the consumable electrode type AC arc welding machine of the present invention, an arc can be supplied stably, and for example, it is useful for welding for performing heat input control such as aluminum.

Configuration diagram of consumable electrode type AC arc welding machine of the present invention Time chart showing embodiment of consumable electrode type AC arc welding machine of the present invention Configuration of conventional consumable electrode type AC arc welder Time chart showing an embodiment of a conventional consumable electrode type AC arc welder

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input alternating current power supply 2 Welding output part 3 1st switching element 4 2nd switching element 5 Consumable electrode 6 Base material 7 Voltage detector 8 Arc / short-circuit determination device 9 Positive polarity / reverse polarity regulator 10 Positive polarity / reverse polarity output control 11 Current detector 12 AND circuit

Claims (1)

A voltage detector connected between the consumable electrode and the base material for detecting the welding output voltage, a current detector connected in series with the welding output circuit for detecting the welding output current, and the arc detected by the detected value of the voltage detector. An arc / short circuit determination device for determining whether the current is short-circuited, a positive polarity / reverse polarity adjuster for adjusting the welding output polarity ratio, and the logical product of the output signal of the arc / short circuit detector and the output signal of the current detector. Consumable electrode type AC arc welding machine provided with a logic circuit to perform, and a positive / reverse polarity controller for controlling positive / reverse polarity output based on the output signal of the positive / reverse polarity adjuster and the output signal of the logic circuit .