JP2011167745A - Arc starting method of multi-electrode one-side welding equipment and multi-electrode one-side welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an arc starting method of multi-electrode one-side welding equipment, a method that excels in cost performance and work efficiency by automating arc start and reducing consumption of an arc generation auxiliary agent, and to provide multi-electrode one-side welding equipment. <P>SOLUTION: The arc starting method of multi-electrode one-side welding equipment comprises: a first step in which an arc generation auxiliary agent is set in a first electrode; a second step in which an arc is generated in the first electrode and in which a welding truck is made to run immediately after the arc generation; a third step in which an arc is generated for the second electrode on a molten pool and in which feeding of a wire to be the second electrode is controlled by three processes consisting of a first process of feeding the wire at slow speed, a second process of stopping the feeding, and a third process of feeding at regular speed that varies in accordance with fluctuation of voltage of the wire; and a fourth step in which an arc is generated for on and after a third electrode on the molten pool and in which the feeding of the wire to be the on and after electrode is controlled by the first to third processes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an arc start method for a multi-electrode single-sided welding apparatus used for large-plate joint arc welding in a ship block manufacturing line at a shipyard, etc., and multi-electrode single-sided welding for starting arc welding by the arc start method. It relates to the device.

  In large joint arc welding at shipyards, etc., single-sided arc welding mainly using multiple electrodes is adopted as a high-efficiency welding method. In recent years, in the shipbuilding industry, automation of the welding process has been attempted for the purpose of improving the efficiency of welding work, and in particular, there has been a strong demand for automation of arc start.

Conventionally, as an arc start method, for example, an arc start method as described in Patent Document 1 and Patent Document 2 is employed.
Patent Document 1 describes an arc start method for a three-electrode single-side welding apparatus. Specifically, arcs are generated at the first and second electrodes, and immediately after that, the traveling of the welding carriage equipped with the first and second electrodes is started, and the arc generation at the third electrode is the first and second. A so-called running start method is described which is generated on a molten pool formed on a material to be welded by an electrode.

  Patent Document 2 describes an arc start method for a four-electrode single-side welding apparatus using an arc generation auxiliary agent. Specifically, while using an arc generation auxiliary agent, at least the third electrode alone or the third electrode and the fourth electrode are simultaneously generated in an arc, and immediately thereafter, an arc is generated in the remaining electrodes, and A stationary start method is described in which the welding cart starts running.

JP-A-4-309471 JP-A-8-52573

  However, in the arc start method described in Patent Document 1, when the distance between the second and third electrodes is relatively large, the molten pool formed by the first and second electrodes is solidified to be in a semi-solid state. Therefore, when the wire serving as the third electrode is fed at a normal speed, the wire collides with the semi-solidified molten pool before the arc is generated. Therefore, there is a problem that the movement of the welding carriage equipped with the first to third electrodes stops, and as a result, no arc can be generated by the third electrode.

  In addition, since the arc generating auxiliary agent is not used in the first and second electrodes, it takes time to generate the arc, and the wires fed as the first and second electrodes collide with the material to be welded. There is also a problem that no arc can be generated in the first and second electrodes due to the stoppage of movement. Furthermore, there is a problem that a phenomenon that a wire, that is, a welding carriage on which an electrode is mounted, is lifted due to the collision of the wire, and the burden on the welding apparatus is large. Therefore, it has been insufficient as an automated arc start method.

  In the arc start method described in Patent Document 2, an arc generation auxiliary agent is used, but it is set after the third electrode that is the succeeding electrode and is not set to the first electrode that is the preceding electrode. Therefore, since the arc generation time at the first electrode, which is the leading electrode, cannot be shortened, the collision of the wire serving as the first electrode with the material to be welded cannot be prevented, and there is a problem that an arc cannot be generated at the first electrode. .

  Moreover, in actual welding, it is necessary to set an arc generation auxiliary agent not only in the third electrode but also in the fourth electrode, and the amount of arc generation auxiliary agent used is increased, which is not economical and the work efficiency is reduced. There is also a problem. Furthermore, a tab plate is provided on the extension of the weld line in order to eliminate welding residue at the welding start part, but since the arc is generated in all electrodes at the start of welding, the tab plate becomes long and not economical. There is also a problem. Therefore, it has been insufficient as an automated arc start method.

  Therefore, the present invention was devised to solve such a problem, and it is possible to automate the arc start by ensuring the arc generation at each electrode, and to reduce the amount of arc generation auxiliary agent used. It is an object of the present invention to provide an arc start method for a multi-electrode single-sided welding apparatus and a multi-electrode single-sided welding apparatus that are excellent also in work efficiency.

  In order to solve the above problems, an arc start method of a multi-electrode single-side welding apparatus according to the present invention arc welds a material to be welded using a number of electrodes mounted on a welding carriage, and the electrodes are fed. An arc start method for a multi-electrode single-side welding apparatus that is a wire, wherein a first step of setting an arc generating auxiliary agent on a first electrode serving as a leading electrode, and an arc on the workpiece to be welded to the first electrode And a second step of causing the welding carriage to run immediately after that, and a second electrode to be a succeeding electrode of the first electrode, and melting in a semi-solid state formed on the workpiece by the first electrode An arc is generated on the pool, and the wire serving as the second electrode is slowed down until the wire contacts the semi-solidified molten pool before the arc is generated. Feed at speed According to the first stage, the second stage in which the feeding is stopped immediately after the wire comes into contact with the semi-solidified molten pool until the arc is generated, and the voltage value of the wire is changed after the arc is generated. The third process controlled in three stages by the third stage that feeds at the variable normal speed, and the electrode after the third electrode that becomes the succeeding electrode of the second electrode, the electrode after the third electrode An arc is generated on the molten pool in a semi-solid state formed on the material to be welded by the preceding electrode, and the first to first wires are fed as the electrodes after the third electrode. And performing a fourth process controlled in three stages of three stages.

  According to the above procedure, since the first step of setting the arc generation auxiliary agent on the first electrode is performed, the time required for arc generation at the first electrode in the second step can be shortened, and the first electrode is fed as the first electrode. The collision of the wire with the material to be welded can be prevented, and since the arc generation auxiliary agent is used only for the first electrode, the amount used is reduced and the working efficiency is also improved. And since an arc is generated only with the 1st electrode used as a preceding electrode at the time of a welding start, the tab board provided in the welding start part can be shortened. Further, in the third step and the fourth step, since the feeding speed of the wire that becomes the second and subsequent electrodes is controlled in three stages, specifically, the slowdown speed that is slower than the normal speed until the arc is generated. In order to control the feeding of the wire in the first stage in which the wire is fed and in the second stage in which the feeding is stopped when the wire comes into contact with the semi-solid melted pool, the wire is melted in the semi-solid state. It can be prevented from colliding with the pool. Therefore, an arc is generated even on the semi-solidified molten pool.

  A multi-electrode single-side welding apparatus according to the present invention is a multi-electrode single-side welding apparatus for arc welding a material to be welded. A wire feeding section for feeding, a welding carriage carrying the electrode, a carriage moving means for moving the welding carriage along a welding line of the material to be welded, and welding for controlling the power supplied to the electrode A power supply processing unit, a wire feeding processing unit for controlling the feeding speed of the wire, and a control unit having a carriage traveling processing unit for controlling the movement of the welding carriage, the wire feeding processing unit, An arc is generated in the preceding electrode on the semi-solidified molten pool formed on the workpiece by the preceding electrode, and the wire serving as the preceding next electrode is fed. Before the occurrence Until the first contact with the molten pool in the semi-solid state is fed at a slowdown speed slower than the normal speed, and immediately after the wire contacts the molten pool in the semi-solid state until an arc is generated. Is controlled in three stages: a second stage for stopping the feeding and a third stage for feeding at the normal speed that varies according to fluctuations in the voltage value of the wire after the occurrence of the arc.

  According to the said structure, the welding power supply process part which controls the power supply supplied to an electrode, the wire feed process part which controls the feed speed of the wire used as an electrode, and the trolley travel process part which controls the movement of a welding cart And the wire feeding processing unit uses an arc generating auxiliary agent to control the feeding of the wire to be the next electrode preceding, that is, the electrode after the second electrode in three stages. The amount is reduced, the working efficiency is improved, and the collision of the wire serving as the electrode can be prevented, and an arc is generated on the semi-solidified molten pool.

  According to the arc start method for a multi-electrode single-side welding apparatus and the multi-electrode single-side welding apparatus according to the present invention, the arc start can be automated by ensuring the arc generation at each electrode, and the amount of arc generation auxiliary agent used is reduced. As a result, the economy and work efficiency are excellent.

It is a flow which shows the procedure of the arc start method of the multi-electrode single-sided welding apparatus which concerns on this invention. It is a time chart in the arc start method of the multi-electrode single-sided welding apparatus which concerns on this invention. It is a perspective view which shows the structure of the multi-electrode single-sided welding apparatus which concerns on this invention. It is a block diagram of the control part in the multi-electrode single-sided welding apparatus which concerns on this invention.

An arc start method for a multi-electrode single-side welding apparatus according to the present invention and a multi-electrode single-side welding apparatus for starting arc welding by the arc start method will be described with reference to the drawings.
First, a multi-electrode single-side welding apparatus will be described with reference to FIGS. Moreover, FIG. 2 is referred as needed.

  As shown in FIG. 3, a multi-electrode single-sided welding device (hereinafter sometimes referred to as a welding device) 1 includes a number of electrodes 2 (first electrode 2a, second electrode 2b, third electrode) mounted on a welding carriage 4. The electrode 2c) is used to arc weld the workpiece W and is a wire to which the electrode 2 is fed. During welding, the control unit 9 controls the carriage moving means 5 to move the welding carriage 4 along the welding line (groove line) V of the welded material W abutted against each other, and By controlling the wire feeding unit 3 with the control unit 9, the feeding speed of the wire serving as the electrode 2 is controlled.

  The welding apparatus 1 is particularly a multi-electrode single-sided submerged arc welding apparatus. In the multi-electrode single-sided submerged arc welding apparatus, the back flux scattered on the copper plate or the like (not shown) from the back side of the weld line V of the welded material W that is abutted to the back surface of the weld line V by a push-up mechanism such as an air hose. The electrodes are pressed together and arc welded using a plurality of electrodes (wires) 2 and a flux supplied from a flux feeder 7 from the surface side of the welding line V at the same time.

  The welding apparatus 1 includes a large number of electrodes 2, an electrode power supply unit 10, a wire feeding unit 3, a welding cart 4, a cart moving means 5, and a control unit 9. Hereinafter, each structure is demonstrated taking the case where the electrode 2 of the welding apparatus 1 is comprised from three electrodes as an example.

(electrode)
A large number of electrodes 2 are mounted on the welding carriage 4 and hang down in series toward the workpiece W, and move along the welding line V of the workpiece W that is abutted by the movement of the welding carriage 4. The electrode 2 is a wire fed from a wire feeding unit 3 to be described later. When power is supplied from the electrode power source unit 10 to the wire, an arc discharge occurs between the electrode 2 and the workpiece W. And welding the weld line V. Specifically, the electrode 2 includes a first electrode 2a, a second electrode 2b, and a third electrode 2c.

(Electrode power supply)
The electrode power supply unit 10 supplies power to the wire serving as the electrode 2, and is provided corresponding to each of the multiple electrodes 2 in the welding apparatus 1. Specifically, the electrode power supply unit 10 is configured to supply power to the first electrode 2a as an electrode power supply unit (first electrode) 10a, and is configured to supply power to the second electrode 2b. Electrode) 10b and an electrode power supply unit (third electrode) 10c for supplying power to the third electrode 2c.

(Wire feeding part)
The wire feeding unit 3 feeds a wire to be the electrode 2, and is provided corresponding to each of a large number of electrodes 2 in the welding apparatus 1. Specifically, the wire feeding unit 3 feeds the wire serving as the first electrode 2a as the wire feeding unit (first electrode) 3a and the wire serving as the second electrode 2b. The wire feeding unit (second electrode) 3b and the wire feeding unit (third electrode) 3c are configured to feed the wire to be the third electrode 2c.

(Welding trolley)
The welding carriage 4 carries the electrode 2 and moves along the welding line V, and includes a support base 4a that supports the electrode 2, a front support arm 4b and a rear support arm 4c that are suspended from the support base 4a, A bridging member 4d is provided between the front support arm 4b and the rear support arm 4c. Further, in the welding carriage 4, a flux feeder 7 for spreading and supplying flux to the welding line V is supported on the support pedestal 4a, and a flux collector 8 for collecting residual flux after welding is supported on the rear support arm 4c. It may be.

(Dolly moving means)
The carriage moving means 5 moves the welding carriage 4 along the welding line V by suspending the welding carriage 4 and moving the traveling rail 11 installed along the longitudinal direction of the welding line V in the installation direction XL. It is something to be made. The carriage moving means 5 includes a suspension member 5a that is movably suspended in a transverse direction YL orthogonal to the installation direction XL of the traveling rail 11, and a motor 5b that drives the suspension member 5a to move in the installation direction XL of the traveling rail 11. And a position detector 5c such as an encoder for detecting the drive amount of the motor 5b. The driving amount of the motor 5b detected by the position detector 5c is transmitted to the storage unit 9A and stored as position coordinates in the erection direction XL of the electrode 2.

(Control part)
The control unit 9 controls the power supplied to the electrode 2, controls the feeding speed of the wire serving as the electrode 2, and controls the movement of the welding carriage 4. A processing unit 9B, a wire feeding processing unit 9C, and a cart traveling processing unit 9D are provided.

  The storage unit 9A is a voltage value at the electrode power supply unit 10, specifically, an initial voltage value supplied to the electrode 2 when the welding apparatus 1 is started, an arc generation voltage value used for determination of arc generation, a wire and a half. The wire contact voltage value used for determining contact with the solidified molten pool is stored. In addition, the storage unit 9A stores the wire feeding speed in the wire feeding unit 3, specifically, the normal speed after arc generation, that is, the normal speed at the time of welding, the slowdown speed slower than the normal speed before arc generation, and the like. Is. The storage unit 9A stores a moving speed of the welding carriage 4 during welding. Furthermore, the storage unit 9A stores electrode position coordinates, molten pool position coordinates, and the like. The molten pool position coordinates correspond to the first to second electrode distances, the first to third electrode distances, and the like.

  The initial voltage value, arc generation voltage value, and wire contact voltage value are input in advance to the storage unit 9A, and are transmitted to the welding power source processing unit 9B, the wire feed processing unit 9C, and the cart travel processing unit 9D. . Further, the normal speed and slow-down speed of the wire are input in advance to the storage unit 9A and are transmitted to the wire feed processing unit 9C. Further, the moving speed of the welding carriage 4, the electrode position coordinates of the electrode 2, and the molten pool position coordinates are input in advance to the storage unit 9A and are transmitted to the welding power source processing unit 9B and the cart traveling processing unit 9D. The electrode position coordinates of the electrode 2 are rewritten by the driving amount of the motor 5b detected by the position detector 5c transmitted from the carriage moving means 5.

  The welding power source processing unit 9B controls the power supplied to the electrode 2, that is, controls the ON / OFF state of the electrode power source unit 10 (see FIG. 2). Specifically, the welding power supply processing unit 9B transmits the initial voltage value transmitted from the storage unit 9A to the electrode power supply unit 10 based on the electrode position coordinates and the molten pool position coordinates transmitted from the storage unit 9A. The electrode power supply unit 10 is switched from the OFF state to the ON state. And when the electrode position coordinate of the 1st electrode 2a which is a preceding electrode is the start time of the welding apparatus 1, ie, "zero", the electrode power supply part 10a of the 1st electrode 2a is turned on. In addition, each of the second electrode 2b and the third electrode 2c, which are the trailing electrodes, has an electrode position coordinate of the preceding electrode, that is, the molten pool of the molten pool formed by the first electrode 2a and the second electrode 2b. When the position coordinates are reached, the electrode power supply units 10b and 10c of the second and subsequent electrodes are switched from the OFF state to the ON state. In addition, the welding power supply process part 9B transmits the electrode voltage value in the electrode 2 after the start of the welding apparatus 1 to the wire feed process part 9C.

  The wire feed processing unit 9C controls the feed rate of the wire to be the electrode 2, that is, controls the feed rate of the wire feed unit 3, and melts in a semi-solid state formed on the material to be welded by the preceding electrode. An arc is generated at the next electrode preceding the pool. Specifically, an arc is generated in the second electrode 2b on the semi-solid melt pool formed on the material to be welded by the first electrode 2a, and the semi-solid melt pool formed by the second electrode 2b. An arc is generated on the third electrode 2c (see FIG. 2). And the control of the feeding speed in the wire feeding processing unit 9C includes the electrode voltage value transmitted from the welding power source processing unit 9B, the initial voltage value transmitted from the storage unit 9A, the wire contact voltage value, and the arc generation voltage value. Is selected, the wire feeding speed transmitted from the storage unit 9A is selected, the selected wire feeding speed is transmitted to the wire feeding unit 3, and the feeding speed of the wire feeding unit 3 is determined. It is something to control. Then, the wire feed processing unit 9C performs a slowdown speed when the electrode voltage value is equal to the initial voltage value, a feed stop command when the electrode voltage value is equal to the wire contact voltage value, and the electrode voltage value is an arc generated. When equal to the voltage value, the normal speed is transmitted to the wire feeding unit 3.

  Here, the slowdown speed is 1/10 to 1/2 of the normal speed although it varies depending on the thickness of the material W to be welded. The normal speed is a speed used when welding the workpiece W, and is 0.5 to 3 m / min, although it varies depending on the thickness of the workpiece W. Then, the normal speed varies according to the fluctuation of the voltage value so that the voltage value at the electrode power supply unit (second electrode) 10b, that is, the voltage value of the wire that is the second electrode 2b is constant. Specifically, the feeding speed is increased as the voltage value increases.

  The cart traveling processing unit 9D controls the movement of the welding cart 4, that is, controls the ON-OFF state of the cart moving means 5 (see FIG. 2). Specifically, the cart traveling processing unit 9D compares the electrode voltage value of the first electrode 2a transmitted from the welding power source processing unit 9B with the arc generation voltage value of the first electrode 2a transmitted from the storage unit 9A. to decide. When the electrode voltage value is equal to the arc generation voltage value, the moving speed transmitted from the storage unit 9A is transmitted to the carriage moving means 5 to control the carriage moving means 5 from the OFF state to the ON state. In the carriage moving means 5, the motor 5b is driven based on the transferred movement speed, and the welding carriage 4 moves.

  In the control unit 9, the storage unit 9A can be configured by a recording medium such as a ROM, a RAM, and an HDD (hard disk). Further, the welding power source processing unit 9B, the wire feeding processing unit 9C, and the cart traveling processing unit 9D can be configured by a processing / calculating device such as a microcomputer or a personal computer.

  The multi-electrode single-sided welding apparatus according to the present invention may include a slider 6 that controls the displacement of the electrode 2 from the welding line V in the transverse direction YL in addition to the above configuration. The slider 6 moves the welding carriage 4 in the transverse direction YL. The slider stage 6a attached to the support base 4a of the welding carriage 4, a motor for moving the slider stage 6a in the transverse direction YL, and driving of the motor The slider driving unit 6b includes a position detector such as an encoder for detecting the amount. Then, the driving amount of the motor detected by the position detector is transmitted to the storage unit 9A and stored as the position coordinates of the electrode 2 in the transverse direction YL. In the multi-electrode single-side welding apparatus, the electrode 2 may be composed of four or more electrodes (not shown).

<Arc start method for multi-electrode single-side welding equipment>
Next, the arc start method of the multi-electrode single-side welding apparatus according to the present invention will be described with reference to FIGS.
The arc start method for a multi-electrode single-side welding apparatus according to the present invention includes the following first to fourth steps. Below, each process is demonstrated taking the case where a multi-electrode single-sided welding apparatus is provided with three electrodes as an example. In addition, about each structure of a multi-electrode single-sided welding apparatus, refer FIG. 3, FIG.

(First step: Step S1)
In the first step, a step S1 of setting an arc generation auxiliary agent on the first electrode 2a serving as the preceding electrode is performed. Further, the arc generating auxiliary agent may be set manually or automatically. Then, by setting the arc generation auxiliary agent, the arc generation at the first electrode 2a is ensured.

  In step S1, when manually setting the arc generation auxiliary agent, for example, using steel wool as the arc generation auxiliary agent, after tearing the steel wool or the like to the required amount, and pressing it to some extent to adjust the shape The material is sandwiched between the first electrode 2a and the workpiece W. Then, the welding start button of the welding apparatus 1 is pushed down and the welding apparatus 1 is started.

  In the step S1, when the arc generation auxiliary agent is automatically set, for example, a cut wire or iron powder is used as the arc generation auxiliary agent and is provided near the first electrode 2a by turning on the power to the welding apparatus 1. An arc generation auxiliary agent is supplied between the first electrode 2a and the material W to be welded from an arc generation auxiliary agent supplier (not shown). The supply amount of the arc generation auxiliary agent is controlled by the control unit 9.

(Second step: Steps S2 to S5)
In the second step, an arc is generated on the material W to be welded on the first electrode 2a, and immediately after that, the welding carriage 4 is caused to travel. Specifically, in the second step, the step S2 for turning on the power of the first electrode 2a, the step S3 for starting the feeding of the wire (first electrode 2a), and the generation of an arc at the first electrode 2a are performed. A step S4 for determining and a step S5 for starting the traveling of the welding carriage 4 are performed.

  In step S2, an initial voltage is applied to the first electrode 2a by the electrode power supply unit (first electrode) 10a by turning on the power to the welding apparatus 1 in the step S1. Here, the initial voltage value of the first electrode 2a is stored in advance in the storage unit 9A and transmitted from the welding power source processing unit 9B to the electrode power source unit (first electrode) 10a.

  In step S3, when an initial voltage is applied to the first electrode 2a in step S2, the wire serving as the first electrode 2a is fed at a predetermined speed by the wire feeding unit (first electrode) 3a. Here, the wire feeding speed is stored in advance in the storage unit 9A and transmitted from the wire feeding processing unit 9C to the wire feeding unit (first electrode) 3a.

  The wire feeding speed at the first electrode 2a is fed at a normal speed that is faster than the wire feeding speed at the second electrode 2b and the third electrode 2c described later. This is because the arc generation auxiliary agent is set in the vicinity of the first electrode 2a in the first step described above, the time required for arc generation is short, and even if the wire is fed at a normal speed, it may collide with the workpiece W. This is because there is not. However, as with the second electrode 2b and the third electrode 2c, the wire feeding at the first electrode 2a may be controlled in the order of slowdown speed, stop, and normal speed. Here, although the slodder one speed and the normal speed will be described below, the normal speed means the speed of the wire fed when the workpiece W is welded.

  In step S4, it is determined whether or not an arc is generated at the first electrode 2a. If yes (Yes), the process proceeds to the next step, and if not (No), an arc occurrence at the first electrode 2a is determined. repeat. Specifically, this judgment is made by using the electrode voltage value at the first electrode 2a in the electrode power supply unit (first electrode) 10a and the arc generation voltage value stored in advance in the storage unit 9A in the cart travel processing unit 9D. This is performed by comparing and judging the two in the cart travel processing unit 9D. Then, it is determined that the electrode voltage value is equal to the arc generation voltage value (Yes). Here, although an arc generation voltage value changes with thickness of the to-be-welded material W etc., it is 20-60V. This determination is not limited to using a voltage value, and may be performed using a characteristic value that can determine the occurrence of an arc, for example, a current value.

  In step S5, the carriage moving means 5 moves the welding carriage 4 along the welding line V at a predetermined movement speed. Here, the moving speed of the welding cart 4 is stored in advance in the storage unit 9 </ b> A and transmitted from the cart travel processing unit 9 </ b> D to the cart moving means 5.

(Third step: Steps S6 to S12)
In the third step, an arc is generated on the second electrode 2b, which is the succeeding electrode of the first electrode 2a, on the semi-solidified molten pool formed on the workpiece W by the first electrode 2a.

  Specifically, in the third step, the step S6 for determining the position of the second electrode 2b, the step S7 for turning on the power of the second electrode 2b, and the feeding of the wire at the second electrode 2b are started. Step S8, Step S9 for determining contact with the wire W to be welded, that is, the molten pool, Step S10 for stopping the feeding of the wire at the second electrode 2b, and determination of arc generation at the second electrode 2b Step S11 to be performed and Step S12 to start feeding the wire at the second electrode 2b are performed.

  In step S6, it is determined whether or not the second electrode 2b has reached the position on the semi-solidified molten pool formed by the first electrode 2a. If reached (Yes), the process proceeds to the next step. If not reached (No), the position determination of the second electrode 2b is repeated. Specifically, this determination is stored in advance in the storage unit 9A and the electrode position coordinates of the storage unit 9A rewritten by the driving amount of the motor 5b detected by the position detector 5c, that is, the movement amount of the welding carriage 4. The molten pool position coordinates are transmitted to the wire feed processing unit 9C, and the wire feed processing unit 9C compares and determines both. Then, it is determined that the electrode position coordinate is equal to the molten pool position coordinate (Yes).

  In step S7, an initial voltage is applied to the second electrode 2b by the electrode power supply unit (second electrode) 10b. Here, the initial voltage value of the second electrode 2b is stored in advance in the storage unit 9A and transmitted from the welding power source processing unit 9B to the electrode power source unit (second electrode) 10b.

  In step S8, the wire serving as the second electrode 2b is fed by the wire feeding unit (second electrode) 3b at a feeding speed and a slow-down speed slower than the normal speed. The slow-down speed is 1/10 to 1/2 of the normal speed, although it varies depending on the thickness of the workpiece W. The normal speed is a speed used when welding the workpiece W, and is 0.5 to 3 m / min, although it varies depending on the thickness of the workpiece W. Here, the wire slow-down speed is stored in advance in the storage unit 9A and transmitted from the wire feed processing unit 9C to the wire feed unit (second electrode) 3b.

  In step S9, it is determined whether or not the wire started to be fed in the previous step S8 has contacted the semi-solidified molten pool formed by the first electrode 2a, and in the case of contact (Yes), the next step In the case of non-contact (No), the contact determination of the second electrode 2b is repeated. Specifically, this determination is made by using the wire feed processing unit 9C based on the electrode voltage value at the second electrode 2b in the electrode power source unit (second electrode) 10b and the wire contact voltage value stored in advance in the storage unit 9A. This is performed by comparing the two in the wire feeding processing unit 9C. And the case where an electrode voltage value is equal to a wire contact voltage value is judged as contact (Yes). Here, the wire contact voltage value is 0V because the wire is in contact with the semi-solidified molten pool.

  In step S10, feeding of the wire to be the second electrode 2b by the wire feeding unit (second electrode) 3b is stopped. Here, the wire feed stop command is transmitted from the wire feed processing unit 9C to the wire feed unit (second electrode) 3b.

  In step S11, it is determined whether or not an arc has occurred in the second electrode 2b. If yes (Yes), the process proceeds to the next step, and if not (No), an arc occurrence in the second electrode 2b is determined. repeat. Specifically, this determination is based on the electrode voltage value at the second electrode 2b in the electrode power source unit (second electrode) 10b and the arc generation voltage value stored in advance in the storage unit 9A by the wire feed processing unit 9C. This is performed by comparing the two in the wire feeding processing unit 9C. Here, although an arc generation voltage value changes with thickness of the to-be-welded material W etc., it is 20-60V. This determination is not limited to using a voltage value, and may be performed using a characteristic value that can determine the occurrence of an arc, for example, a current value.

  In step S12, the wire that is to be the second electrode 2b is fed at a normal speed by the wire feeding unit (second electrode) 3b. Then, the normal speed varies according to the fluctuation of the voltage value so that the voltage value at the electrode power supply unit (second electrode) 10b, that is, the voltage value of the wire that is the second electrode 2b is constant. Specifically, the feeding speed is decreased as the voltage value increases. Here, the normal speed of the wire is stored in advance in the storage unit 9A and transmitted from the wire feed processing unit 9C to the wire feed unit (second electrode) 3b.

By performing the above-described steps S6 to S12, the feeding speed of the wire to be fed is controlled in the following three stages. Thereby, the arc generation at the second electrode 2b is ensured even on the semi-solidified molten pool.
(First stage): Before the arc is generated, the wire is fed at a slow-down speed until it comes into contact with the workpiece W, that is, the semi-solidified molten pool.
(Second stage): Feeding of the wire is stopped immediately after the wire comes into contact with the molten pool until an arc is generated.
(Third stage): After the arc is generated, the wire is fed at a normal speed that varies according to fluctuations in the voltage value of the wire.

(4th process: Process S13-S19)
In the fourth step, an arc is generated on the third electrode 2c serving as the succeeding electrode of the second electrode 2b on the semi-solidified molten pool formed on the workpiece W by the second electrode 2b.

  Specifically, in the fourth step, the step S13 for determining the position of the third electrode 2c, the step S14 for turning on the power of the third electrode 2c, and the feeding of the wire at the third electrode 2c are started. Step S15, Step S16 for determining contact with the molten pool of wire, Step S17 for stopping the feeding of the wire at the third electrode 2c, Step S18 for determining the occurrence of arc at the third electrode 2c, The process S19 which starts feeding of the wire by the 3rd electrode 2c is performed.

  Steps S13 to S19 are the same steps as steps S6 to S12 performed on the second electrode 2b described above, and the description thereof will be omitted. In Steps S13 to S19, the electrode power supply unit is formed by the electrode power supply unit (third electrode) 10c, the wire feeding unit is formed by the wire feeding unit (third electrode) 3c, and the molten pool is formed by the second electrode 2b. It is.

  By performing the above-described steps S6 to S19, the feeding speed of the wire to be fed is controlled in the three stages described above. Thereby, the generation of the arc of the third electrode 2c is ensured even on the semi-solidified molten pool.

  Although the arc start method of the welding apparatus provided with three electrodes was demonstrated above, the above-mentioned arc start method can be used also in the welding apparatus provided with four or more electrodes. Specifically, in the above-described fourth step, steps S13 to S19 are followed by steps similar to steps S13 to S19 (not shown) after the fourth electrode.

1 Multi-electrode single-sided welding equipment (welding equipment)
2 Electrode 3 Wire feeding unit 4 Welding cart 5 Cart moving means 9 Control unit 10 Electrode power supply unit

Claims (2)

An arc start method for a multi-electrode single-side welding apparatus, wherein a welding material is arc-welded using a large number of electrodes mounted on a welding carriage, and the electrode is a wire to be fed;
A first step of setting an arc generating auxiliary agent on the first electrode to be the leading electrode;
A second step of causing the first electrode to generate an arc on the material to be welded and immediately running the welding carriage;
An arc is generated on the second electrode, which is a subsequent electrode of the first electrode, on the molten pool in a semi-solid state formed on the material to be welded by the first electrode, and becomes the second electrode A first stage of feeding the wire at a slowdown speed slower than a normal speed until the wire comes into contact with the semi-solidified molten pool before the arc is generated; and the wire is in the semi-solid state A second stage in which feeding is stopped immediately after contact with the molten pool until an arc is generated, and a third stage in which feeding is performed at the normal speed that varies according to fluctuations in the voltage value of the wire after the arc is generated. A third process controlled in three stages according to
On the semi-solidified molten pool formed on the material to be welded by the electrode preceding the third electrode and subsequent electrodes to the electrode subsequent to the third electrode, which becomes the succeeding electrode of the second electrode. A multi-electrode single-side welding apparatus characterized by performing a fourth step of generating an arc and controlling feeding of a wire to be an electrode after the third electrode in three stages of the first to third stages. Arc start method. A multi-electrode single-side welding apparatus for arc welding a workpiece,
Many electrodes,
An electrode power supply for supplying power to the electrodes;
A wire feeding section for feeding a wire to be the electrode;
A welding carriage carrying the electrodes;
A carriage moving means for moving the welding carriage along a weld line of the workpiece,
A control unit having a welding power source processing unit for controlling power supplied to the electrodes, a wire feeding processing unit for controlling the feeding speed of the wire, and a cart traveling processing unit for controlling movement of the welding cart; With
The wire feed processing unit generates an arc on the next electrode that precedes the molten pool in a semi-solid state formed on the material to be welded by the preceding electrode, and becomes the preceding next electrode. A first stage of feeding the wire at a slowdown speed slower than a normal speed until the wire comes into contact with the semi-solidified molten pool before the arc is generated; and the wire is in the semi-solid state A second stage in which feeding is stopped immediately after contact with the molten pool until an arc is generated, and a third stage in which feeding is performed at the normal speed that varies according to fluctuations in the voltage value of the wire after the arc is generated. A multi-electrode single-side welding apparatus characterized by being controlled in three stages.

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