CA1228896A - Welding system for tig-welding - Google Patents
Welding system for tig-weldingInfo
- Publication number
- CA1228896A CA1228896A CA000456684A CA456684A CA1228896A CA 1228896 A CA1228896 A CA 1228896A CA 000456684 A CA000456684 A CA 000456684A CA 456684 A CA456684 A CA 456684A CA 1228896 A CA1228896 A CA 1228896A
- Authority
- CA
- Canada
- Prior art keywords
- welding
- current
- circuit
- value
- welded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
- B23K9/067—Starting the arc
- B23K9/0671—Starting the arc by means of brief contacts between the electrodes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
- B23K9/073—Stabilising the arc
Abstract
Abstract The invention relates to a welding system for Tig welding. To initiate welding, a tungsten electrode is brought momentarily into contact with the object to be welded and then separated from the object to initiate an arc. A low short-circuit current is led through the welding circuit during this contact. The interruption of the low short-circuit current is used to control the welding power source to increase the current in the welding circuit to a value above a preset welding current value intended for the welding process proper. After a short period of time, the current is decreased to the preset value. This system permits welding to be carried out safely and easily and without electrode "drag" marks being formed on the article to be welded.
Description
,889~
Welding system for Yielding The present invention concerns an electronically operating circuit, which is meant to be mounted on operating welding rectifiers having basic current circuits.
The known Twig welding systems can be split into two types dependent on the way in which the welding is started.
The first system uses scrape ignition, in which the voltaic arc is established by scraping the electrode against the article to be welded until a spark is obtained This method causes a 'drag' in the material upon starting and stopping, and tungsten material is left on the welded article, which means that the resulting weld has a poor quality appearance. In addition, the welding electrode must be removed and ground frequently. Another system uses a contact free start by means of a high tension generator, which starts the voltaic arc when a spark is established. The drawback of this system is that the spark moves in a circle on the article to be welded, and the place where the welding is started cannot be precisely controlled. Furthermore this system is very expensive.
From British patent specification no. 2,054,293 a welding system is known which counteracts the drawbacks of the scrape ignition system. In this system, a soft start is obtained by coupling together a high tension via a separate transformer winding with an existing rectifier, which is synchronized with the main frequency. When the 1~28~96 voltaic arc is established, the system electronically changes over to a normal slope-up circuit by means of a new rectifier. This is a rather expensive method of advanced scrape ignition which also includes an expensive choke coil. The user also has the possibility of getting an electric shock if a filler metal is employed.
According to the invention there is provided a method for the electronic control of the starting process in TWIG
welding, in which a tungsten electrode is brought into momentary contact with the object to be welded, and then separated from said object to initiate an arc, wherein a low short-circuit current is led through the welding circuit during said contact, and wherein the interruption of said low short-circuit current is used to control the welding power source to increase the current in the welding circuit to a value above a preset welding current value intended for the welding process proper, and thereupon, after a short period of time, to decrease the current to remain at said preset value.
The invention differs from the known systems because high tension is not required for starting and the required adjustment takes place as a current regulation.
The invention consists of an electronically operated circuit which is meant to be mounted on welding rectifiers having a basic current circuit.
The peculiar thing about the invention is that the welding electrode can be placed directly on the article to be welded before the welding voltaic arc has been established, because only the basic current of 3-8 A will pass through the electrode. When the electrode is lifted from the article, the basic current is raised to twice the preset welding current, and a voltaic arc is established.
The current is then immediately lowered to the value the slope-up function has achieved. The slope-up function of the operated circuit thereafter regulates the current up to the preset welding current. It the article to be welded ~'~2~9f~
is touched during the welding operation, the circuit will regulate the welding current down to the basic current level which protects the electrode.
When the button on the welding handle is released, a down-slope will take place, which brings about a slow lowering of the welding current to the basic current level and the welding stops. The slope function avoids the formation of a 'drag' in the material.
During the welding with the preset welding current it is possible, by trigging a burner switch to pulsate the welding current for controlling the molten bath. The control circuit also regulates the gas-stream in the magnetic valve in a way that provides both for- and after-streaming of argon. This is done to make the start easier and to avoid oxidizing the electrode during the cooling.
The advantages of the invention are that a 'drag' is avoided and that the starting point of the weld can be controlled very precisely.
The invention will be described in more detail in the following with reference to the accompanying drawing, in which:
Fig. 1 shows a block diagram of a circuit according to a preferred embodiment of the present invention.
The welding system has to be connected with a thruster operated welding rectifier with internal basic current circuit. The welding is described with MODE switch 11 in position for Twig welding. The tungsten electrode on the welding handle 6 is placed on the article to be welded.
The switch on the welding handle 1 is closed and Montana-ante circuit 2 is activated. This causes the magnetic valve 3 to open and the gas regulating circuit 4 causes the gas streaming to start. After the gas streaming has stopped the basic current circuit on-off 5 is activated, which turns on the basis current to the electrode 6. When the electrode is lifted by a small amount from the article
Welding system for Yielding The present invention concerns an electronically operating circuit, which is meant to be mounted on operating welding rectifiers having basic current circuits.
The known Twig welding systems can be split into two types dependent on the way in which the welding is started.
The first system uses scrape ignition, in which the voltaic arc is established by scraping the electrode against the article to be welded until a spark is obtained This method causes a 'drag' in the material upon starting and stopping, and tungsten material is left on the welded article, which means that the resulting weld has a poor quality appearance. In addition, the welding electrode must be removed and ground frequently. Another system uses a contact free start by means of a high tension generator, which starts the voltaic arc when a spark is established. The drawback of this system is that the spark moves in a circle on the article to be welded, and the place where the welding is started cannot be precisely controlled. Furthermore this system is very expensive.
From British patent specification no. 2,054,293 a welding system is known which counteracts the drawbacks of the scrape ignition system. In this system, a soft start is obtained by coupling together a high tension via a separate transformer winding with an existing rectifier, which is synchronized with the main frequency. When the 1~28~96 voltaic arc is established, the system electronically changes over to a normal slope-up circuit by means of a new rectifier. This is a rather expensive method of advanced scrape ignition which also includes an expensive choke coil. The user also has the possibility of getting an electric shock if a filler metal is employed.
According to the invention there is provided a method for the electronic control of the starting process in TWIG
welding, in which a tungsten electrode is brought into momentary contact with the object to be welded, and then separated from said object to initiate an arc, wherein a low short-circuit current is led through the welding circuit during said contact, and wherein the interruption of said low short-circuit current is used to control the welding power source to increase the current in the welding circuit to a value above a preset welding current value intended for the welding process proper, and thereupon, after a short period of time, to decrease the current to remain at said preset value.
The invention differs from the known systems because high tension is not required for starting and the required adjustment takes place as a current regulation.
The invention consists of an electronically operated circuit which is meant to be mounted on welding rectifiers having a basic current circuit.
The peculiar thing about the invention is that the welding electrode can be placed directly on the article to be welded before the welding voltaic arc has been established, because only the basic current of 3-8 A will pass through the electrode. When the electrode is lifted from the article, the basic current is raised to twice the preset welding current, and a voltaic arc is established.
The current is then immediately lowered to the value the slope-up function has achieved. The slope-up function of the operated circuit thereafter regulates the current up to the preset welding current. It the article to be welded ~'~2~9f~
is touched during the welding operation, the circuit will regulate the welding current down to the basic current level which protects the electrode.
When the button on the welding handle is released, a down-slope will take place, which brings about a slow lowering of the welding current to the basic current level and the welding stops. The slope function avoids the formation of a 'drag' in the material.
During the welding with the preset welding current it is possible, by trigging a burner switch to pulsate the welding current for controlling the molten bath. The control circuit also regulates the gas-stream in the magnetic valve in a way that provides both for- and after-streaming of argon. This is done to make the start easier and to avoid oxidizing the electrode during the cooling.
The advantages of the invention are that a 'drag' is avoided and that the starting point of the weld can be controlled very precisely.
The invention will be described in more detail in the following with reference to the accompanying drawing, in which:
Fig. 1 shows a block diagram of a circuit according to a preferred embodiment of the present invention.
The welding system has to be connected with a thruster operated welding rectifier with internal basic current circuit. The welding is described with MODE switch 11 in position for Twig welding. The tungsten electrode on the welding handle 6 is placed on the article to be welded.
The switch on the welding handle 1 is closed and Montana-ante circuit 2 is activated. This causes the magnetic valve 3 to open and the gas regulating circuit 4 causes the gas streaming to start. After the gas streaming has stopped the basic current circuit on-off 5 is activated, which turns on the basis current to the electrode 6. When the electrode is lifted by a small amount from the article
2~3~96 to be welded, the welding voltaic arc and the idle voltage control 7 is activated. This will activate the start pulse circuit 8. The welding current circuit 9 shortly lifts the welding current to establish a stable welding voltaic arc - bigger than the value set on the control After a stable voltaic arc has been obtained the current falls to a value just above the basic current value. At the same time that the voltaic arc is established the control of the welding voltaic arc 7 will start for the slope-up function 10. This means that the welding current will rise for a short time to a value determined by the preset value-control 12.
When the welding is to be stopped, the Twig burner switch 1 is turned off, by means of which the slope-down regulation 10 starts to regulate down through the regulation circuit 9. When the regulation to the basic current level is obtained the maintenance circuit 2 is zero-set and the basic current circuit on-off 5 turns off for the basic current in the welding rectifier. At the same time, the gas regulating circuit 4 causes the gas after streaming to start. After that the magnetic valve 3 has been turned off, the gas after streaming is stopped.
The time for after streaming avoids oxidizing the electrode during the cooling.
Tack welding can be carried out by changing the MODE
switch to the tack-welding position. The welding then works in the same way as for Twig welding, though the up and down slope time is shortened to milliseconds.
Electrode welding can be carried out by changing the MODE switch to the electrode welding position. This means that the basic current circuit is constantly activated.
The slope function 10 and the gas regulating circuit 4 are uncoupled. Normal electrode welding can then be carried out with coupled up equipment.
When the welding is to be stopped, the Twig burner switch 1 is turned off, by means of which the slope-down regulation 10 starts to regulate down through the regulation circuit 9. When the regulation to the basic current level is obtained the maintenance circuit 2 is zero-set and the basic current circuit on-off 5 turns off for the basic current in the welding rectifier. At the same time, the gas regulating circuit 4 causes the gas after streaming to start. After that the magnetic valve 3 has been turned off, the gas after streaming is stopped.
The time for after streaming avoids oxidizing the electrode during the cooling.
Tack welding can be carried out by changing the MODE
switch to the tack-welding position. The welding then works in the same way as for Twig welding, though the up and down slope time is shortened to milliseconds.
Electrode welding can be carried out by changing the MODE switch to the electrode welding position. This means that the basic current circuit is constantly activated.
The slope function 10 and the gas regulating circuit 4 are uncoupled. Normal electrode welding can then be carried out with coupled up equipment.
Claims (3)
1. A method for the electronic control of the starting process in TIG welding, in which a tungsten electrode is brought into momentary contact with the object to be welded, and then separated from said object to initiate an arc, wherein a low short-circuit current is led through the welding circuit during said contact, and wherein the interruption of said low short-circuit current is used to control the welding power source to increase the current in the welding circuit to a value above a preset welding current value intended for the welding process proper, and thereupon, after a short period of time, to decrease the current to remain at said preset value.
2. A method of electronic control according to claim 1, wherein any later contact between the tungsten electrode and the object to be welded during the welding process proper is used to control the welding power source to immediately decrease the welding current to said low short-circuit current value.
3. A method of electronic control according to claim 1, wherein the closing of a switch on the TIG welding torch will initiate a gradual slope-down of the welding current until said low current value has been reached, whereupon the power source is turned off.
I. A method of electronic control according to claim 1, claim 2 or claim 3 wherein the low short-circuit current is in the range of 3 to 8 A.
I. A method of electronic control according to claim 1, claim 2 or claim 3 wherein the low short-circuit current is in the range of 3 to 8 A.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DK274283A DK152413B (en) | 1983-06-15 | 1983-06-15 | TIG WELDING WELDING SYSTEM |
| DK2742/83 | 1983-06-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1228896A true CA1228896A (en) | 1987-11-03 |
Family
ID=8115309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000456684A Expired CA1228896A (en) | 1983-06-15 | 1984-06-15 | Welding system for tig-welding |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS60501548A (en) |
| AU (1) | AU565763B2 (en) |
| CA (1) | CA1228896A (en) |
| DE (2) | DE3490272C2 (en) |
| DK (1) | DK152413B (en) |
| FI (1) | FI850602L (en) |
| FR (1) | FR2548067B1 (en) |
| GB (1) | GB2156607B (en) |
| NO (1) | NO850569L (en) |
| SE (1) | SE8500692D0 (en) |
| WO (1) | WO1985000024A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4809014B2 (en) | 2005-07-29 | 2011-11-02 | 株式会社ダイヘン | Arc start control method for robot welding |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE532472A (en) * | 1953-10-14 | |||
| GB881531A (en) * | 1958-11-21 | 1961-11-08 | Rolls Royce | Improvements in and relating to gas shielded arc welding |
| DE1565062A1 (en) * | 1965-04-23 | 1970-01-15 | Siemens Ag | Arrangement for arc stabilization of controllable multi-process welding rectifiers |
| DE1615363C3 (en) * | 1967-07-04 | 1974-11-07 | Messer Griesheim Gmbh, 6000 Frankfurt | Device for stabilizing and igniting welding arcs using current pulses |
| DE1937879B2 (en) * | 1969-07-25 | 1970-10-22 | Kurt Stork | Stabilizing arc circuit for aluminium welding - with non-consumable tungsten electrode |
| DE2407703A1 (en) * | 1974-02-18 | 1975-08-28 | Ewert Poort | Arc initiator for welding apparatus - arc struck with apparatus at maximum output is subsequently reduced to chosen output |
| DE2459309A1 (en) * | 1974-12-14 | 1976-06-16 | Messer Griesheim Gmbh | Arc ignition for arc welding - with current supply set at lower value while electrodes touch to reduce loading |
| US4282569A (en) * | 1979-07-12 | 1981-08-04 | Union Carbide Corporation | Constant current welding power supply with an upslope starting current |
| AT373109B (en) * | 1981-05-22 | 1983-12-27 | Elin Union Ag | CIRCUIT ARRANGEMENT FOR RAISING THE IGNITION CURRENT IN A BRUSHLESS ROTATING WELDING MACHINE |
| JPS5870975A (en) * | 1981-10-23 | 1983-04-27 | Ishikawajima Harima Heavy Ind Co Ltd | Emergency stopping method in tig welding |
-
1983
- 1983-06-15 DK DK274283A patent/DK152413B/en not_active Application Discontinuation
-
1984
- 1984-05-25 DE DE19843490272 patent/DE3490272C2/de not_active Expired - Lifetime
- 1984-05-25 GB GB08503548A patent/GB2156607B/en not_active Expired
- 1984-05-25 DE DE19843490272 patent/DE3490272T1/en active Pending
- 1984-05-25 AU AU30173/84A patent/AU565763B2/en not_active Ceased
- 1984-05-25 JP JP50223484A patent/JPS60501548A/en active Pending
- 1984-05-25 WO PCT/DK1984/000049 patent/WO1985000024A1/en active Application Filing
- 1984-06-14 FR FR8409336A patent/FR2548067B1/en not_active Expired
- 1984-06-15 CA CA000456684A patent/CA1228896A/en not_active Expired
-
1985
- 1985-02-13 FI FI850602A patent/FI850602L/en not_active Application Discontinuation
- 1985-02-14 NO NO850569A patent/NO850569L/en unknown
- 1985-02-14 SE SE8500692A patent/SE8500692D0/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| DE3490272C2 (en) | 1990-11-22 |
| GB2156607A (en) | 1985-10-09 |
| FR2548067B1 (en) | 1988-01-15 |
| JPS60501548A (en) | 1985-09-19 |
| FI850602A0 (en) | 1985-02-13 |
| FI850602L (en) | 1985-02-13 |
| AU565763B2 (en) | 1987-09-24 |
| AU3017384A (en) | 1985-01-11 |
| GB2156607B (en) | 1986-11-12 |
| DK152413B (en) | 1988-02-29 |
| DE3490272T1 (en) | 1985-07-25 |
| DK274283A (en) | 1984-12-16 |
| FR2548067A1 (en) | 1985-01-04 |
| SE8500692L (en) | 1985-02-14 |
| GB8503548D0 (en) | 1985-03-13 |
| WO1985000024A1 (en) | 1985-01-03 |
| NO850569L (en) | 1985-02-14 |
| SE8500692D0 (en) | 1985-02-14 |
| DK274283D0 (en) | 1983-06-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |