JP2023162631A - Plasma arc hybrid welding device - Google Patents

Abstract

To provide a plasma arc hybrid welding device that uses, in combination, plasma welding and arc welding which can increase a joint width of a weld region.SOLUTION: A plasma arc hybrid welding device 1 which uses plasma welding and consumable electrode-type arc welding in combination, comprises: a first welding torch 30 that is used in the consumable electrode-type arc welding; a second welding torch 20 provided separately in a progressing direction of welding from the first welding torch, and used in the plasma welding; and a weaving device 10 that makes the second welding torch 20 perform weaving motion in a direction crossing the progressing direction of welding, in the plasma welding. The plasma arc hybrid welding device 1 makes the welding progress so that a weld region, which is welded by the plasma welding using the second welding torch 20 that is made to perform weaving motion by the weaving device in a base material to be welded, is further welded by the consumable electrode-type arc welding using the first welding torch 30.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a plasma arc hybrid welding device that uses both plasma welding and arc welding.

In a conventional welding method that uses both plasma welding and arc welding, the plasma electrode is hollow and the welding wire, which is supplied with power via a power supply tip placed inside the plasma electrode, is fed through the hollow shape. There is a plasma MIG welding method in which a MIG arc is generated by applying a MIG welding voltage and passing a MIG welding current between a power supply tip and a base metal (Patent Document 1). In such a plasma MIG welding method, the plasma electrode is weaved in order to improve the fit of the bead toe.

Japanese Patent Application Publication No. 2013-163219

However, in the welding device that implements the welding method described in Patent Document 1, the plasma electrode and the power supply tip are arranged coaxially, and the weaving operation of the plasma electrode is restricted, so the welding area cannot be joined. There was a problem that the width became narrow.

An object of the present disclosure is to provide a plasma arc hybrid welding device that uses both plasma welding and arc welding, which can increase the width of the joint in the welding area.

The present disclosure relates to a plasma arc hybrid welding device that uses both plasma welding and consumable electrode arc welding. The plasma arc hybrid welding device includes a first welding torch used for consumable electrode arc welding, a second welding torch provided spaced apart from the first welding torch in the welding progress direction and used for plasma welding, and a second welding torch used for plasma welding. and a weaving device for weaving the second welding torch in a direction intersecting the welding direction. Plasma arc hybrid welding equipment performs consumable electrode arc welding using a first welding torch to weld a welding area that has been welded by plasma welding using a second welding torch that is weaved by a weaving device on the base material to be welded. Welding is further progressed by further welding.

According to the plasma arc hybrid welding device of the present disclosure, it is possible to increase the joint width of the welding region.

1 is a configuration diagram of a plasma arc hybrid welding apparatus 1 for carrying out the plasma arc hybrid welding method of Embodiment 1. FIG. FIG. 3 is a plan view of base material 4 showing a weaving operation state of second welding torch 20 in plasma arc hybrid welding apparatus 1 according to the first embodiment. 2 is a diagram showing a distribution of heat input in the welding width direction by the plasma arc hybrid welding apparatus 1 of the first embodiment. FIG. 7 is a flowchart showing a processing procedure for controlling the output of the second welding torch 20 according to the profile of the distribution of heat input by consumable electrode type arc welding.

Embodiments of the present invention will be described in detail below with reference to the drawings. Although a plurality of embodiments will be described below, it has been planned from the beginning of the application to appropriately combine the configurations described in each embodiment. In addition, the same reference numerals are attached to the same or corresponding parts in the drawings, and the description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a configuration diagram of a plasma arc hybrid welding apparatus 1 for implementing the plasma arc hybrid welding method of the first embodiment.

The plasma arc hybrid welding device 1 includes a welding torch unit WT and a power supply unit PS. Power supply unit PS includes a plasma welding power supply device 11 and an arc welding power supply device 12. Welding torch unit WT includes a first welding torch 30, a second welding torch 20, a weaving device 10, and a gas nozzle (not shown).

The first welding torch 30 is a welding torch used for consumable electrode arc welding, and includes a power supply tip 3 and a welding wire 7. Consumable electrode arc welding includes various types of consumable electrode arc welding, such as MIG welding or MAG welding. The second welding torch 20 is a welding torch used for plasma welding, and includes a plasma electrode 2. The second welding torch 20 is provided apart from the first welding torch 30 in the welding direction. The direction of welding progress is indicated by an arrow in the figure. Weaving device 10 includes a weaving mechanism 8 and a weaving drive device 9.

In the welding torch unit WT, a shielding gas such as argon gas or a mixed gas of argon gas and carbon dioxide gas is supplied from the gas nozzle. In the first welding torch 30 , a welding wire 7 is fed through a through hole provided in the power feeding tip 3 . The power supply tip 3 is electrically connected to the welding wire 7. However, welding wire 7 is insulated from plasma electrode 2. Although not shown, the welding wire 7 is fed by rotation of a feed roll using a feed motor as a driving source.

In the second welding torch 20, the plasma electrode 2 is made of copper or a copper alloy, for example. The plasma electrode 2 is preferably cooled directly or indirectly by cooling water.

The welding torch unit WT is held by a robot or the like and moves relative to the base material 4 in the welding direction shown by the arrow in the figure. In the second welding torch 20 , a plasma arc 5 is generated between the plasma electrode 2 and the base material 4 . In the first welding torch 30 , a consumable electrode type arc 6 is generated between the tip of the welding wire 7 and the base material 4 . In the following description, the arc generated in plasma welding will be referred to as a plasma arc, and the consumable electrode type arc generated in consumable electrode type arc welding will be simply referred to as an arc, so that the names will be distinguished.

The plasma welding power supply device 11 is a power supply for applying a plasma welding voltage between the plasma electrode 2 and the base material 4 to supply a plasma welding current. The arc welding power supply device 12 is a power supply for supplying an arc welding current by applying an arc welding voltage between the welding wire 7 and the base material 4 to be welded via the power supply tip 3.

The plasma welding power supply device 11 includes a microcomputer, and the microcomputer also has a function of controlling the above-mentioned plasma welding current and a function of controlling the weaving device 10 to cause the second welding torch 20 to perform a weaving operation. In this way, the plasma welding power supply device 11 also has a function as a control device.

The arc welding power supply device 12 includes a microcomputer, and the microcomputer also has the function of controlling the above-mentioned arc welding current and the function of controlling the feed speed of the welding wire 7 in the first welding torch 30. In this way, the arc welding power supply device 12 also has a function as a control device.

The weaving mechanism 8 is a mechanism that causes the second welding torch 20 to perform a weaving operation. The weaving mechanism 8 is driven by a weaving drive device 9 to cause the second welding torch 20 to perform a weaving operation. The weaving drive device 9 includes a drive source including a stepping motor and a drive circuit for the drive source. Plasma welding power supply device 11 sends a control signal to the drive circuit of weaving drive device 9 . The weaving mechanism 8 uses a mechanism that converts the rotational motion of a stepping motor in the weaving drive device 9 into linear motion using a slider crank mechanism. Note that the weaving mechanism 8 may have any other structure, such as a rack and pinion mechanism, as long as it converts the rotational motion of the stepping motor into linear motion. Further, the weaving drive device 9 may use a motor other than a stepping motor as a drive source.

The second welding torch 20 is caused to perform a weaving operation in a direction that intersects with the welding progress direction. In the weaving drive device 9, a stepping motor is controlled by a control signal supplied from a plasma welding power supply device 11. In the weaving mechanism 8, the rotational motion of the stepping motor in the weaving drive device 9 is converted into linear motion by the slider crank mechanism, thereby weaving the second welding torch 20 in a direction intersecting the welding direction. The weaving mechanism 8 and the weaving drive device 9 constitute a weaving device 10.

In the plasma arc hybrid welding apparatus 1, when welding, the welding torch unit WT is moved in the welding direction shown by the arrow. When welding is performed in this way, the welding area that has been welded by plasma welding using the second welding torch 20 that is weaved by the weaving device 10 on the base material 4 to be welded is replaced by the first welding torch 30. The welding progresses to further welding by the consumable electrode type arc welding used.

In other words, when welding is performed by the plasma arc hybrid welding device 1, the welding area of the base material 4 is first welded by plasma arc using the second welding torch 20 that is weaved by the weaving device 10. This is followed by welding by consumable electrode arc welding using the first welding torch 30.

FIG. 2 is a plan view of the base material 4 showing a weaving operation state of the second welding torch 20 in the plasma arc hybrid welding apparatus 1 of the first embodiment.

Referring to FIG. 2, an operation image of the weaving operation of the second welding torch 20 is shown by an operation pattern 21. In the motion pattern 21, the direction of progress of the weaving motion is indicated by an arrow. In the welding area 22, which is the joining area when the plasma arc hybrid welding device 1 performs welding to join the base metals 4, the width W1 of the weaving operation of the second welding torch 20 is equal to the joining width W2 in the welding area 22. It is set to be 0.5 times (1/2×W2) or more.

In the weaving device 10, when welding is performed with the plasma arc hybrid welding device 1, the weaving drive device 9 drives the weaving mechanism 8, so that welding is performed with the width W1 set as described above. Welding torch 20 is caused to perform a weaving operation. The weaving operation of the second welding torch 20 is performed at regular intervals. The period of the weaving operation of the second welding torch 20 is controlled by the plasma welding power supply device 11.

FIG. 3 is a diagram showing the distribution of heat input in the welding width direction by the plasma arc hybrid welding apparatus 1 of the first embodiment. FIG. 3A shows the distribution of heat input in plasma welding by the plasma arc from the second welding torch 20. FIG. 3B shows the distribution of heat input in consumable electrode type arc welding using the arc from the first welding torch 30. FIG. 3C shows the distribution of the sum of the heat input due to the plasma arc from the second welding torch 20 and the heat input due to the arc from the first welding torch 30. That is, FIG. 3(c) shows the distribution of the total heat input of plasma welding using the plasma arc from the second welding torch 20 and consumable electrode type arc welding using the arc from the first welding torch 30. In each figure, the vertical axis indicates the heat input amount Q, and the Y-axis direction indicates the welding joint width direction. The amount of heat input Q is the total amount of heat input (J) from the start to the end of welding at each point in the width direction.

As shown in FIG. 3(a), the distribution of heat input due to the plasma arc from the second welding torch 20 has a profile in which the heat input is small at the center C in the width direction and increases toward both ends. be.

As shown in FIG. 3(b), the distribution of the heat input due to the arc from the first welding torch 30 has a profile in which the heat input is large at the center C in the width direction, and the heat input decreases toward both ends. . Therefore, the heat distribution of the sum of the heat input due to the plasma arc from the second welding torch 20 and the heat input due to the arc from the first welding torch 30 is approximately uniform in the width direction, as shown in FIG. 3(c). It becomes.

In the plasma arc hybrid welding apparatus 1, considering the profile of heat input by the arc from the first welding torch 30 as shown in FIG. 3(b), the plasma arc from the second welding torch 20 as shown in FIG. 3(a) is The heat distribution profile of the sum of the heat input by the arc and the heat input by the arc from the first welding torch 30 as shown in FIG. 3(b) is made substantially uniform in the width direction as shown in FIG. 3(c). , the weaving pattern of the plasma arc from the second welding torch 20 is determined, and the profile of its heat input amount is determined. Based on the profile of the amount of heat input by the plasma arc from the second welding torch 20, output control of the plasma arc from the second welding torch 20 is performed by the plasma welding power supply device 11.

The output control of the plasma arc from the second welding torch 20 is performed by the plasma welding power supply device 11, for example, as follows. In the plasma welding power supply device 11, the current weaving operation position of the second welding torch 20 is confirmed from the weaving operation pattern of the second welding torch 20, and the weaving operation position is determined as described above according to the confirmed weaving operation position. The output of the plasma arc is controlled so that the amount of heat input corresponds to the profile of the amount of heat input by the plasma arc.

Since the mechanical properties of the welding area are determined by the amount of heat input into the welding area and the heat distribution of each welding process, as described above, the amount of heat input by the plasma arc from the second welding torch 20 and the arc from the first welding torch 30 By adjusting the sum of the heat input amount and the heat input amount, desired mechanical properties can be obtained in the welding area. By equalizing the sum of the heat input due to the plasma arc from the second welding torch 20 and the heat input due to the arc from the first welding torch 30 in the width direction, the generated intermetallic compounds are concentrated in one part. It is possible to form a high quality weld bead without any damage.

In particular, when welding dissimilar materials (for example, welding aluminum alloy sheets and hot-dip galvanized steel sheets), controlling the amount and distribution of intermetallic compounds requires controlling the amount and distribution of molten metal. There is a need to. In the first embodiment, by adjusting the profile of the heat input by the plasma arc from the second welding torch 20, it is possible to mainly adjust the melting of the base metal, and the weld bead width and the depth of the molten pool can be adjusted. (penetration depth) and its distribution can be adjusted. Further, by adjusting the output of the first welding torch 30 using the arc welding power supply device 12, it is possible to mainly adjust the melting of the welding wire 7, and the amount of molten metal can be adjusted.

Next, an example of a control process related to output control of the second welding torch 20 executed by the plasma welding power supply device 11 will be described. FIG. 4 is a flowchart showing a processing procedure for controlling the output of the second welding torch 20 according to the profile of the distribution of heat input by consumable electrode arc welding.

In the plasma welding power supply device 11, the microcomputer executes the following process when controlling the output of the second welding torch 20 according to the profile of the distribution of heat input by consumable electrode arc welding.

In step S1, it is checked whether the current state is the state after the start of the welding operation. If the state is not after the start of the welding operation in step S1, that is, if it is determined that the state is before the start of the welding operation, in step S2, the Obtain data on the heat distribution profile of heat input. The profile data acquired in step S1 is stored in advance in the memory included in the plasma welding power supply device 11.

In step S3, from the heat distribution profile of the heat input in consumable electrode arc welding as shown in FIG. A profile of the heat distribution of the heat input amount of plasma welding as shown in FIG. 3(a), which can make the sum of the heat amount uniform in the width direction, is determined. In step S3, the data of the determined profile is stored in the memory included in the plasma welding power supply device 11.

In the microcomputer of the plasma welding power supply device 11, data on the relationship between welding current and heat input, which indicates the relationship between the plasma welding current applied by the plasma welding power supply 11 and the heat input due to the plasma arc, is stored in a memory.

In step S4, the determination is made in step S3 based on the data of the heat distribution profile of the plasma welding heat input determined in step S3 and the data showing the relationship between the welding current and the heat input stored in the memory. Welding current table data is created that shows the correlation between the weaving operation position and the welding current value, which makes it possible to realize the heat distribution profile of the heat input of plasma welding. In step S4, data of the created welding current table is stored in the memory included in the plasma welding power supply device 11.

Thereafter, if the current state is determined to be a state after the start of the welding operation in step S1 described above, that is, a state in which the welding operation is being performed, in step S5, the second welding torch 20 in plasma welding is Get the data of the current weaving operation position. In step S5, when the plasma arc hybrid welding device 1 performs the welding operation, the stepping motor control signal (number of pulse signals) sent from the plasma welding power supply device 11 to the weaving drive device 9 is monitored. Recognize the current rotation angle of and obtain data of the current weaving operation position corresponding to the current rotation angle. Note that the current weaving operation position of the second welding torch 20 is obtained by providing a sensor capable of detecting the position of the second welding torch 20, such as an image sensor, and detecting the current weaving operation position with such a sensor. You may.

In step S6, the welding current corresponding to the data of the current weaving operation position acquired in step S5 is determined from the data of the welding current table created in step S4. Thereby, a welding current that realizes the profile of the heat distribution of the plasma welding heat input determined in S3 is determined in accordance with the current weaving operation position.

In step S7, the welding current value for plasma welding is controlled to the welding current value determined in step S6. Thereby, plasma welding is controlled by the plasma welding power supply device 11 so that the amount of heat input by the plasma arc from the second welding torch 20 has a heat distribution profile as shown in FIG. 3(a).

Note that the above-described processing of steps S2 to S4 is performed as an example after the plasma arc hybrid welding apparatus 1 is powered on and before the welding operation is started. However, the processes of steps S2 to S4 described above may be executed in advance by a computer different from the microcomputer of the plasma welding power supply device 11. In that case, the data of the heat distribution profile of the plasma welding heat input determined in step S3 and the data of the welding current table created in step S4 are stored in a storage medium different from the memory of the plasma welding power supply 11. The data may be stored in the memory of the plasma welding power supply 11 by storing the data in the storage medium and transferring the data from the storage medium to the memory of the plasma welding power supply 11.

By executing the processes of steps S1 to S7 described above, the plasma welding power supply device is configured such that the amount of heat input by the plasma arc from the second welding torch 20 has a heat distribution profile as shown in FIG. 3(a). 11 allows plasma welding to be controlled.

According to the plasma arc hybrid welding apparatus 1 of the first embodiment described above, as shown in FIG. spaced apart in the direction of travel. Then, the welding area 22 welded by plasma welding using the second welding torch 20 that is weaved by the weaving device 10 on the base material 4 to be welded is welded by consumable electrode type arc welding using the first welding torch 30. By proceeding with the welding so that the welding is further performed, the weaving operation is no longer restricted, so that the width of the joint width in the plasma welding region can be increased.

Further, as shown in FIG. 2, the width W1 of the weaving operation of the second welding torch 20 is set to be 0.5 times (W2×1/2) or more the joining width W2 in the welding area 22. Ru. Thereby, the width W1 of the weaving operation of the second welding torch 20 can be set to an appropriate width, and the welding strength of the welding region 22 can be increased.

Further, as shown in FIG. 3(a), the profile of the distribution of heat input in the width direction of the welding area 22 by consumable electrode arc welding is that the heat input in the width direction of the welding area 22 is from the center to both ends. is a decreasing profile. According to such a profile, in steps S5 to S7 in FIG. 4, the welding current in plasma welding is adjusted so that the heat input increases in the width direction of the welding area 22 from the center to both ends. control, it is possible to equalize the sum of the heat input due to the plasma arc from the second welding torch 20 and the heat input due to the arc from the first welding torch 30 in the width direction. It is possible to form a high quality weld bead in which the compound is not concentrated in one part.

[Embodiment 2]
In the second embodiment, an example will be described in which short-circuit transition welding is performed in the consumable electrode type arc welding of the plasma arc hybrid welding apparatus 1 shown in the first embodiment. Embodiment 1 shows an example in which short-circuit transition welding is not performed. Short-circuit transfer welding is arc welding in which molten metal transfers to the base metal each time the welding wire 7 contacts a molten pool in which molten metal has accumulated due to heat from an arc during welding. Short-circuit transition welding can be performed, for example, by setting a welding current value lower than a standard welding current value to shorten the arc length.

The short-circuit transition welding in the second embodiment can be realized by the same configuration as in FIGS. 1 to 4 shown in the first embodiment. As described above, in the consumable electrode type arc welding of the plasma arc hybrid welding apparatus 1 having the configuration shown in Embodiment 1, if the welding current is controlled by the arc welding power supply device 12 and short circuit transition welding is performed, the following can be achieved. Technical effects can be obtained.

In plasma welding in the plasma arc hybrid welding apparatus 1, a weaving operation is performed, so the distance between the electrodes changes in plasma welding and consumable electrode arc welding during the weaving operation. When the distance between poles changes, a problem occurs in plasma welding and consumable electrode arc welding in that the applied electromagnetic force changes and the generated arc tends to become unstable.

In the second embodiment, by performing short-circuit transition welding in which the arc length is short in consumable electrode arc welding, the arc in consumable electrode arc welding can be stabilized.

In the configuration in which short-circuit transition welding is performed in consumable electrode arc welding according to the second embodiment, the following welding results were obtained.

In a lap fillet joint between a 1.6 mm thick galvanized steel plate and a 2.0 mm thick aluminum plate, the conditions for plasma welding performed as preliminary welding were a weaving width of 5.0 mm, a weaving frequency of 10 Hz, and a welding current of 100 A. Welding was carried out under the conditions of consumable electrode type arc welding in which short-circuit transition welding was performed as trailing welding: a welding current of 100 A and a welding speed of 1.0 m/min. As a result of this welding, while securing a joint width of 5.0 mm in the welding direction, melting of the base metal was suppressed only to the surface, and the generation of intermetallic compounds was suppressed. This made it possible to join without cracking. On the other hand, when welding was performed without weaving in plasma welding, the fusion width became narrow and overlap occurred, and the base metal melted and cracks occurred in the base metal.

As explained above, according to the plasma arc hybrid welding apparatus 1 of the first and second embodiments, the second welding torch 20 used for plasma welding, and the first welding torch 30 used for consumable electrode type arc plasma welding. is provided at a distance in the welding process, plasma welding for welding weaving is performed as the preceding welding, and consumable electrode arc welding is performed as the trailing welding, so the weaving operation is no longer restricted. The width of the welding area of plasma welding can be increased.

In addition, in Embodiments 1 and 2, in consumable electrode type arc welding, an example was shown in which the weaving operation is not performed with respect to the first welding torch 30. However, the present invention is not limited to this, and the first welding torch 30 may perform a weaving operation.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments described above, and it is intended that all changes within the meaning and range equivalent to the claims are included.

1 plasma arc hybrid welding device, 30 first welding torch, 20 second welding torch, 10 weaving device.

Claims (4)

A plasma arc hybrid welding device that uses plasma welding and consumable electrode arc welding together,
a first welding torch used for the consumable electrode type arc welding;
a second welding torch provided apart from the first welding torch in the welding progress direction and used for the plasma welding;
In the plasma welding, a weaving device that performs a weaving operation of the second welding torch in a direction crossing the welding direction;
The welding area that has been welded by the plasma welding using the second welding torch that is weaved by the weaving device on the base material to be welded is further welded by the consumable electrode type arc welding using the first welding torch. A plasma arc hybrid welding device that progresses welding as if welding. The plasma arc hybrid welding device according to claim 1, wherein the width of the weaving operation by the weaving device is at least 0.5 times the width of the joint in the welding region. The profile of the distribution of heat input in the width direction of the welding area by the consumable electrode arc welding is a profile in which the heat input decreases from the center toward both ends in the width direction of the welding area,
According to the profile, the method further comprises a control device that controls the welding current in the plasma welding so that the amount of heat input increases in the width direction of the welding region from the center toward both ends. The plasma arc hybrid welding device according to claim 1 or claim 2. 3. The plasma arc hybrid welding apparatus according to claim 1, wherein short circuit transition welding is performed in the consumable electrode arc welding.

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