US4456813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot wire type arc welding system
Assignee: Mitsubishi Electric Corp
•
Filing: 1982-12-30
•
Granted: 1984-06-26
•
Expires: 2002-12-30
Abstract
Abstract In a welding apparatus employing a switching element between a power source and a filler wire, a protection circuit operates to discontinue the function of the switching element when a short-circuit is detected between, for example, the filler wire and a welding electrode, so that the switching element is protected from damage due to an overcurrent.
Inventors
- 👤 Masanori Mizuno
- 👤 Yoshiaki Kato
- 👤 Takaji Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:23
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/10; B23K9/1093
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
146 words
A hot wire type arc welding system, comprising; an electrode, a filler wire fed between said electrode and a base metal, a first switching element connected between said wire and a DC source, said first switching element being adapted to control a wire heating voltage, a second switching element for controlling a welding current, wire heating voltage control means for detecting a wire heating voltage and controlling the on-off operation of said first switching element, a current detector for detecting said welding current, arc current control means for controlling the on-off operation of said second switching element, short-circuit detecting means for detecting a short-circuit between said electrode and said wire, and a protecting circuit for controlling said wire heating voltage control means in response to a detection signal from said short-circuit detecting means, to halt the wire heating voltage control function of said first switching element.
Claim 2
Dependent Claim
146 words
A hot wire type arc welding system, comprising; an electrode, a filler wire fed between said electrode and a base metal, a first switching element connected between said wire and a DC source, said first switching element being adapted to control a wire heating voltage, a second switching element for controlling a welding current, wire heating voltage control means for detecting a wire heating voltage and controlling the on-off operation of said first switching element, a current detector for detecting said welding current, arc current control means for controlling the on-off operation of said second switching element, short-circuit detecting means for detecting a short-circuit between said electrode and said wire, and a protecting circuit for controlling said wire heating voltage control means in response to a detection signal from said short-circuit detecting means, to halt the wire heating voltage control function of said first switching element.
Claim 3
Dependent Claim
77 words
A system as claimed in claim 1, in which said short-circuit detecting means comprises a voltage detecting circuit for detecting a voltage between said electrode and said filler wire; a voltage setting unit for setting a voltage comprising a reference voltage with respect to a detection voltage provided by said voltage detecting circuit; and a voltage comparator for comparing said detection voltage of said voltage detecting circuit with said reference voltage provided by said voltage setting unit.
Claim 4
Dependent Claim
46 words
A system as claimed in claim 2, in which said protecting circuit comprises means for applying a control signal to said wire heating voltage control means when said detection voltage of said voltage detecting circuit becomes lower than said reference voltage of said voltage setting unit.
Claim 5
Dependent Claim
61 words
A system as claimed in claim 3, in which said heating voltage control means comprises a voltage detector for detecting a voltage between said filler wire and said base metal; and a comparison circuit for comparing a detection voltage of said voltage detector with a set voltage, to output a signal for controlling the on-off operation of said first switching element.
Claim 6
Dependent Claim
40 words
A system as claimed in claim 4, wherein a control signal from said protecting circuit is applied to said comparison circuit in precedence over a detection voltage signal from said voltage detector, to maintain said first switching element turned off.
Claim 7
Dependent Claim
15 words
A system as claimed in claim 5, wherein said first switching element comprises transistor means.
Claim 8
Dependent Claim
15 words
A system as claimed in claim 6, wherein said electrode is a non-consumable tungsten electrode.
Claim 9
Dependent Claim
57 words
A system as claimed in claim 1, wherein said short-circuit detecting means comprises a current setting unit for setting a current comprising a reference current with respect to a detection current from said current detector; and a current comparator for comparing a detection current of said current detector with said reference current of said current setting unit.
Claim 10
Dependent Claim
45 words
A system as claimed in claim 8, wherein said protecting circuit comprises means for applying a control signal to said wire heating current control means when said detection current of said current detecting circuit becomes larger than said reference current of said current setting unit.
Claim 11
Dependent Claim
60 words
A system as claimed in claim 9, wherein said wire heating voltage controlling means comprises a voltage detector for detecting a voltage between said wire and said base metal; and a comparison circuit for comparing a detection voltage of said voltage detector with a set voltage, to output a signal for controlling the on-off operation of said first switching element.
Claim 12
Dependent Claim
39 words
A system as claimed in claim 10, wherein a control signal from said protecting circuit is applied to said comparison circuit in precedence over a detection signal from said voltage detector, to maintain said first switching element turned off.
References Cited (Backward Citations)
JPS5597877A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |