JP5199802B2 - 2-wire welding method - Google Patents

Description

  The present invention relates to a two-wire welding method using a consumable electrode wire and a filler wire.

  Two-wire welding using a consumable electrode wire and a filler wire is known as one method for improving the welding speed and improving the appearance of the weld bead (for example, Patent Document 1). FIG. 4 shows an example of conventional two-wire welding. For the two-wire welding shown in the figure, a welding torch including contact tips 91A and 91B is used. The wire WA is supplied through the contact chip 91A. Further, the filler wire WB is supplied to the wire WA from the rear in the welding direction through the contact tip 91B.

  The contact tip 91A is connected to a welding power source (not shown). This welding power source applies a voltage between the contact tip 91A and the welding base material P. As a result, an arc 92 from the wire WA toward the welding base material P is generated. The wire WA is fed from a supply device (not shown) at a speed corresponding to the strength of the arc 92. On the other hand, the filler wire WB is fed by a feeding device (not shown) toward the molten pool Mp generated by the arc 92. Filler wire WB is melted by the heat of molten pool Mp. As a result, the melted wire WA, filler wire WB, and weld base material P are solidified in an alloy state, whereby a weld bead Wp is formed.

  For example, in order to weld relatively thick plates, the arc current is set large. In order to flow a large arc current, the diameter of the wire WA is preferably thick. On the other hand, in order to weld relatively thin plates, the arc current is set small. In order to flow a small arc current, the diameter of the wire WA is preferably narrow. If the magnitude of the arc current and the diameter of the wire WA are too unbalanced, there arises a problem that the arc current is insufficient or that spatter is excessively generated. For this reason, it is necessary to take measures to change the diameter of the wire WA each time depending on the thickness of the welding base material P which is the welding object.

JP 2006-175458 A

  The present invention has been conceived under the circumstances described above, and provides a two-wire welding method capable of performing appropriate welding even if the thickness of the welding object is different. Let it be an issue.

In the two-wire welding method provided by the present invention, a voltage is applied between the consumable electrode wire and an object to be welded so that an arc is generated from the consumable electrode wire and proceeds in the welding direction. A two-wire welding method for supplying a filler wire from the rear in the welding direction, using first and second wires arranged in the welding direction, the first wire as the consumable electrode wire, and the second A first direction welding mode in which a wire is welded so that the first wire precedes the wire, the second wire is the consumable electrode wire, the first wire is the filler wire, and the second wire is the filler wire. A second direction welding mode in which welding is performed so that the first wire and the second wire have different diameters. Through both the first direction welding mode and the second direction welding mode, the product of the cross-sectional area and the feeding rate of the filler wire is to be proportional to the arc current of the arc, feed rate and the above filler wire It is characterized by setting an arc current.

According to such a configuration, even if the filler wire has a relatively small diameter or a relatively large diameter, the appearance of the weld bead is good by reducing the spatter by setting the feeding speed according to the arc current. Appropriate welding can be performed. Further, according to such a configuration, bidirectional welding can be realized without replacing the welding torch and the first and second wires. Moreover, according to such a structure, welding of the said comparatively thin welding object and welding of the said comparatively thick said welding object can be performed, without replacing | exchanging the said 1st wire and the said 2nd wire. .

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 and 2 show an example of a welding system used in the two-wire welding method according to the present invention. The welding system A of this embodiment includes welding torches 1A and 1B, wire feeding devices AWF and BWF, a welding power source PS, a robot RB, and a robot controller RC. The welding system A performs two-wire welding using the wires WA and WB.

  The welding torches 1A and 1B are, for example, substantially cylindrical nozzles and are generally attached to the robot RB. The torch 1A has a through-hole through which the wire WA can be inserted. The torch 1B has a through hole through which the wire WB can be inserted. The wires WA and WB are arranged in parallel to each other, and the direction in which they are arranged is the welding direction. The welding torches 1A and 1B are moved by the robot RB along this welding direction.

  The wire feeding devices AWF and BWF are for feeding the wires WA and WB, respectively, and have a drive source such as a motor (not shown). The wire feeding devices AWF and BWF feed the wire WA and the wire WB at a feeding speed that meets the welding conditions in accordance with a command from the welding power source PS. An energization terminal 2A is provided between the wire feeding device AWF and the welding torch 1A. The energizing terminal 2A is electrically connected to the wire WA while the wire WA is inserted therethrough. Similarly, an energization terminal 2B is provided between the wire feeder BWF and the welding torch 1B.

  The robot controller RC has a function of controlling the operation of the robot RB and a function of outputting an arc current setting signal Is, an arc voltage setting signal Vs, and a welding direction setting signal Ds to the welding power source PS. The robot controller RC is provided with a teach pendant TP. In the teach pendant TP, the welding operator inputs the operation of the robot RB by programming and inputs the welding conditions. From these input operations and welding conditions, the robot controller RC generates an arc current setting signal Is, an arc voltage setting signal Vs, and a welding direction setting signal Ds by a preinstalled program.

  When the operation of the robot RC and the welding conditions are input from the teach pendant TP so that the wire WA precedes in the welding direction, the wire WA is used as a consumable electrode wire and the wire WB is used as a filler wire in that section. A direction setting signal Ds is set. On the other hand, when the operation of the robot RC and the welding conditions are input from the teach pendant TP so that the wire WB precedes in the welding direction, the wire WB is used as a consumable electrode wire and the wire WA is used as a filler wire in that section. Thus, the welding direction setting signal Ds is set.

  The welding power source PS is a power source for generating the arc 3 between the wire WA or the wire WB and the welding base material P, and includes welding power source circuits APS and BPS. The welding power supply circuit APS is connected to the energizing terminal 2A and applies a voltage for generating the arc 3 from the wire WA to flow the current Iw. The welding power supply circuit BPS is connected to the energization terminal 2B, and flows a current Iw by applying a voltage for generating the arc 3 from the wire WB as shown in FIG. Further, feed speed setting signals AWf and BWf are sent from the welding power source PS to the wire feeding devices AWF and BWF.

  The welding direction setting signal Ds is a signal for selectively selecting which of the wires WA and WB is used as a consumable electrode wire and which is used as a filler wire. The welding power source PS alternatively operates the welding power source circuits APS and BPS according to the welding direction setting signal Ds. FIG. 1 shows a case where a welding direction setting signal Ds instructing to use the wire WA as a consumable electrode wire is sent, and the welding power supply circuit APS is set to the ON state and the welding power supply circuit BPS is set to the OFF state. . This mode is referred to as a first direction welding mode. On the other hand, FIG. 2 shows a case where a welding direction setting signal Ds instructing to use the wire WB as a consumable electrode wire is sent, and the welding power supply circuit BPS is set to the ON state and the welding power supply circuit APS is set to the OFF state. ing. This mode is referred to as a second direction welding mode.

  FIG. 3 shows the relationship between the arc current Iw and the welding amount Mw of the filler wire per unit time. In this graph, four types of filler wires having diameters of 0.9, 1.0, 1.2, and 1.6 mm are used. The welding amount Mw indicates the amount of welding when the arc current Iw is set to several sizes and the feeding speed of the filler wire is set so that appropriate welding is performed according to each size. Appropriate welding refers to welding in which excessive spatter is not scattered during welding and the appearance of the weld bead WP is adjusted. From this graph, it can be seen that the arc current Iw and the welding amount Mw have a good proportional relationship regardless of the diameter of the filler wire. The welding amount Mw is the product of the cross-sectional area of the filler wire and the feeding speed.

  In the welding power source PS, using the proportional relationship described above, when the wire WB is used as a filler wire as shown in FIG. 1, the product of the feeding speed BVf and the cross-sectional area of the wire WB is proportional to the arc current Iw. The feeding speed BVf is set so as to satisfy the relationship. Similarly, when the wire WA is used as a filler wire as shown in FIG. 2, the feed speed AVf is set so that the product of the feed speed AVf and the cross-sectional area of the wire WA is proportional to the arc current Iw. Is done.

  An example of a welding method using the welding system A is shown below.

[Example 1]
The diameters of the wires WA and WB were each 1.2 mm, and the arc current Iw was set to 150 to 300A. In this case, an iron base metal P having a thickness of 2.0 to 6.0 mm could be welded at a welding speed of 50 to 150 cm / min. In this embodiment, only the welding direction is different between the first direction welding mode shown in FIG. 1 and the second direction welding mode shown in FIG. 2, and other welding conditions are substantially the same.

[Example 2]
The diameter of the wire WA was 0.9 mm, and the diameter of the wire WB was 1.6 mm. In the first direction welding mode in which the wire WA is used as a consumable electrode wire, the arc current Iw is set to a relatively small current of 50 to 100A. In this case, an iron welding base material P having a thickness of 0.8 to 1.5 mm could be welded at a welding speed of 50 to 150 cm / min. On the other hand, in the second direction welding mode in which the wire WB is used as a consumable electrode wire, the arc current Iw was set to a relatively large current of 200 to 500A. In this case, an iron welding base material P having a thickness of 3.0 to 10 mm could be welded at a welding speed of 50 to 150 cm / min.

  Next, the effect | action of the 2-wire welding method of this embodiment is demonstrated.

  According to this embodiment, even if the wires WA and WB used as filler wires have a relatively small diameter or a relatively large diameter, the spattering can be performed by setting the feeding speed AWf or BWf according to the arc current Iw. Appropriate welding can be performed with a small appearance of the weld bead WP.

  For example, in the case of Example 1, when welding the same welding base material P, the welding direction can be changed extremely by appropriately switching between the first direction welding mode and the second direction welding mode. Thereby, when welding is performed along a greatly bent welding line, the amount of rotation of the arm of the robot RB can be suppressed, and the operation of the robot RB can be rationalized.

  Furthermore, in the case of the second embodiment, the welding base material having significantly different thicknesses can be obtained by appropriately switching between the first direction welding mode and the second direction welding mode without replacing the welding torches 1A and 1B and the wires WA and WB. P can be welded. As a result, for example, in manufacturing one structure, when welding steel plates having different thicknesses, the manufacturing time can be shortened. When welding is performed to form a relatively thin weld bead WP, the magnitude of the arc current Iw is set to be relatively small. In this case, by selecting the wire WA having a relatively small diameter as the consumable electrode wire, it is possible to stably generate a small current arc and to perform welding smoothly. On the other hand, if the magnitude of the arc current Iw is relatively large when the consumable electrode wire has a relatively large diameter, spatter scattering from the molten pool Mp can be effectively suppressed.

  The two-wire welding method according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the two-wire welding method according to the present invention can be varied in design in various ways.

  The wires WA and WB are not limited to the thicknesses of the above-described embodiments, and may be appropriately set according to the material, thickness, welding speed, and the like of the welding base material P. The welding power source PS used in the two-wire welding method of the present invention is not limited to one having the welding power source circuits APS and BPS individually, and has a configuration in which one welding power source circuit is also used for energizing the wires WA and WB by switching. May be. The process of setting the feeding speeds AWf and BWf based on the magnitude of the welding current Iw is not limited to being performed by the welding power source PS, and may be performed by another control device such as the robot controller RC.

It is a system schematic diagram showing the 1st direction welding mode of the welding method concerning the present invention. It is a system schematic diagram showing the 2nd direction welding mode of the welding method concerning the present invention. It is a graph which shows the relationship between an arc current and the amount of filler wire welding. It is a system schematic diagram showing an example of a conventional welding method.

Explanation of symbols

A Welding system APS, BPS Welding power supply circuit AVf, BVf Feeding speed AWF, BWF Wire feeding device AWf, BWf Feeding speed setting signal Ds Welding direction setting signal Is Arc current setting signal Iw Arc current Mp Weld pool P Welding base material (Welding object)
PS Welding power source RB Robot RC Robot controller TP Teach pendant Vs Arc voltage setting signal WA (First) Wire WB (Second) Wire Wp Welding beads 1A, 1B Welding torches 2A, 2B Current-carrying terminal 3 Arc

Claims (1)

While advancing in the welding direction while generating an arc from the consumable electrode wire by applying a voltage between the consumable electrode wire and the welding object,
A two-wire welding method for supplying a filler wire from the rear in the welding direction to the consumable electrode wire,
Using first and second wires lined up along the welding direction,
A first direction welding mode in which the first wire is the consumable electrode wire, the second wire is the filler wire, and welding is performed so that the first wire precedes;
A second direction welding mode in which the second wire is used as the consumable electrode wire, the first wire is used as the filler wire, and welding is performed so that the second wire precedes.
The first wire and the second wire have different diameters,
Through both the first direction welding mode and the second direction welding mode, the filler wire feed rate and the product of the filler wire cross-sectional area and feed rate are proportional to the arc current of the arc. A two-wire welding method, wherein the arc current is set .

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