EP0072683A2
Expired / Lapsed
EP
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DC welding power supply system
Assignee: Kobe Steel Ltd
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Filing: 1982-08-13
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Granted: —
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Expires: 2002-08-13
Abstract
Abstract A welding DC power supply system suitable for consum- - able or non-consumable electrode welding, comprising a plural number of inverter units (10) adapted to convert a first direct current into an alternate current and to rectify the alternate current to produce an output of a second direct current; a circuit connecting the output of terminals of the inverter units in parallel; a detection circuit (25) for detecting the total output current of the inverter units; and a circuit for varying the number of operating inverter units according to the value of the detected total output current. According to other aspects of the invention, the power supply system is further provided with a phase control means (120) for controlling the phases of alternate currents produced by the respective inverter units (10), or means for selectively actuating a particular inverter unit (10A, 10B) or units in a short circuit period of large current in dip transfer welding, or feedback means for suppressing the current in a controlled timing in the final stage of each short circuit period to prevent spattering as caused by bursting rupture of the large short circuit current.
Inventors
- 👤 Kazuo Murase
- 👤 Toshihiko Watanabe
- 👤 Naoki Takeuchi
- 👤 Tokuji Maruyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 17:40
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/10; B23K9/1006; B23K9/06; B23K9/1075
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
90 words
A DC power supply system for consumable or non-consumable electrode welding, comprising: a plurality of inverter units adapted to convert a first direct current into an alternate current and to rectify the alternate current to produce an output of a second direct current; a circuit connecting the output terminals of said inverter units in parallel relation; a detection circuit for detecting the total output current of said inverter units; and a circuit for varying the number of operating inverter units according to the value of the detected total output current.
Claim 2
Dependent Claim
90 words
A DC power supply system for consumable or non-consumable electrode welding, comprising: a plurality of inverter units adapted to convert a first direct current into an alternate current and to rectify the alternate current to produce an output of a second direct current; a circuit connecting the output terminals of said inverter units in parallel relation; a detection circuit for detecting the total output current of said inverter units; and a circuit for varying the number of operating inverter units according to the value of the detected total output current.
Claim 3
Dependent Claim
94 words
A DC welding power supply system as set forth in claim 1, wherein said circuit for varying the number of operating inverter units comprises: a load current detector; a current indexer with a preset current value lower than the output current equivalent to the total rated output current of said inverter units; and a comparator adapted to compare the output signals of said load current detector and current indexer and to produce an output signal if said load current is lower than said predetermined current value, thereby de-actuating a selected inverter unit or units.
Claim 4
Dependent Claim
32 words
A DC welding power supply system as set forth in claim 1, further comprising a phase control means for controlling said inverter units to produce alternate currents with a predetermined phase lag.
Claim 5
Dependent Claim
100 words
A DC welding power supply system as set forth in claim 3, wherein said phase control means comprises: a triangular wave generator for generating plural numbers of triangular waves of different phases; an indexing means setting a predetermined value; a load detector for detecting the level of the load; an error amplifier adapted to produce an output signal corresponding to the difference between the output signals of said indexing means and said load detector; and comparators provided for the respective triangular waves to determine the pulse width by comparing a corresponding triangular wave with the output of said error amplifier.
Claim 6
Dependent Claim
68 words
A DC welding power supply system as set forth in claim 4, wherein said indexing means is a voltage indexer, presetting the value of the total output voltage of said inverter units; said load detector is a voltage detector watching the total output voltage of said inverter units; and said error amplifier is operated on the basis of the output signals of said voltage indexer and voltage detector.
Claim 7
Dependent Claim
64 words
A DC welding power supply system as set forth in claim 4, wherein said indexing means is a current indexer presetting the value of the total output current of said inverter units; said load detector is a current detector watching the total output current of said inverter units; and said error amplifier is operated on the basis of said current indexer and current detector.
Claim 8
Dependent Claim
170 words
A DC welding power supply system as set forth in claim 3, wherein said phase control means comprises: a triangular wave generator for generating a plural number of triangular waves of different phases; a voltage detector for detecting the voltage at an output terminal connecting said inverter units in parallel relation; a voltage error amplifier adapted to produce an output signal corresponding to the difference between the value of voltage detected by said voltage detector and the preset value of said current indexer; a current detector for detecting the current at said output terminal connecting said inverter units in parallel relation; a current error amplifier adapted to produce an output corresponding to the difference between the value of current detected by said current detector and the preset value of said current indexer; a logical sum circuit connected to the output terminals of said voltage error amplifier and current error amplifier; and a plural number of comparators for comparing the respective triangular waves with the output of said logical sum circuit.
Claim 9
Dependent Claim
124 words
A power supply system for dip transfer welding with a consumable electrode, said power supply system comprising: a first inverter unit adapted to generate a voltage suitable for arcing periods; a second inverter unit connected in parallel with said first inverter unit and adapted to generate a voltage suitable for short circuit periods; a first control circuit for controlling the voltage and current of said first inverter unit; a second control circuit for controlling the current of said second inverter unit; the output of said first inverter unit being fed to said consumable electrode in arcing periods, and the output of said second inverter unit being fed to said consumable electrode in short circuit periods along with the output of said second inverter unit.
Claim 10
Dependent Claim
124 words
A power supply system for dip transfer welding with a consumable electrode, said power supply system comprising: a first inverter unit adapted to generate a voltage suitable for arcing periods; a second inverter unit connected in parallel with said first inverter unit and adapted to generate a voltage suitable for short circuit periods; a first control circuit for controlling the voltage and current of said first inverter unit; a second control circuit for controlling the current of said second inverter unit; the output of said first inverter unit being fed to said consumable electrode in arcing periods, and the output of said second inverter unit being fed to said consumable electrode in short circuit periods along with the output of said second inverter unit.
Claim 11
Dependent Claim
65 words
A power supply system as set forth in claim 8, wherein said second control circuit comprises: a voltage detection means for detecting the output voltage of said power supply system; a voltage indexer presetting a voltage intermediate between the arc voltage and the short circuit voltage; and a circuit for de-actuating said second inverter unit when said output voltage is higher than said preset voltage.
Claim 12
Dependent Claim
56 words
A power supply system as set forth in claim 8, wherein said first control circuit comprises: a voltage control means for controlling the output voltage of said power supply system at a preset value in arcing periods; and a current control means for controlling the output current of said power supply system at a preset value.
Claim 13
Dependent Claim
40 words
A power supply system as set forth in claim 8, wherein said second control circuit comprises a current control means for controlling the output current of said second inverter unit according to the output current of said power supply system.
Claim 14
Dependent Claim
149 words
A power supply system for use in dip transfer welding in which a short circuit period and an arcing period alternately take place, said power supply system comprising: a voltage detector for detecting the output voltage of said power supply system; a memory for reading and storing the lowest output voltage of said power supply system in each short circuit period; a trigger circuit for triggering reading and erasing operations of said memory; a level indicator; a comparator adapted to produce an output signal when the difference between the output voltage detected by said voltage detector and the lowest output voltage stored in said memory is greater than the output signal of said level indicator; a final-stage short circuit current indexer; and a welding power output for producing a current of a value specified by said final-stage short circuit current indicator in response to a signal from said comparator.
Claim 15
Dependent Claim
149 words
A power supply system for use in dip transfer welding in which a short circuit period and an arcing period alternately take place, said power supply system comprising: a voltage detector for detecting the output voltage of said power supply system; a memory for reading and storing the lowest output voltage of said power supply system in each short circuit period; a trigger circuit for triggering reading and erasing operations of said memory; a level indicator; a comparator adapted to produce an output signal when the difference between the output voltage detected by said voltage detector and the lowest output voltage stored in said memory is greater than the output signal of said level indicator; a final-stage short circuit current indexer; and a welding power output for producing a current of a value specified by said final-stage short circuit current indicator in response to a signal from said comparator.
Claim 16
Dependent Claim
47 words
A power supply system as set forth in claim 12, wherein said trigger circuit comprises a second comparator for discriminating between short circuit and arcing periods and sending command signals to said memory to start reading in short circuit periods and to erase memory in arcing periods.
Claim 17
Dependent Claim
88 words
A power supply system as set forth in claim 12, wherein said trigger circuit comprises: a second comparator for discriminating between short circuit and arcing periods; a third comparator for discriminating a short circuit current reaching a preset value; and a logic circuit for determining the instructions to be sent to said memory upon receipt of output signals of said second and third comparators, dispatching a command signal to start reading when said short circuit period and a command signal to erase memory upon generation of an arc.
Claim 18
Dependent Claim
49 words
A power supply system as set forth in claim 12, wherein said level indicator comprises a current detector for detecting the output current of said power supply system and a multiplier, producing an output signal obtained by multiplying the output signal of said current detector by a predetermined constant.
Claim 19
Dependent Claim
38 words
A power supply system as set forth in claim 15, wherein said power output comprises a primary rectifier, an inverter, a transformer and a secondary rectifier, and in which said inverter has a frequency higher than 5 kHz.
References Cited (Backward Citations)
No citation records indexed.
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