JP4401324B2 - Single-sided arc welding equipment - Google Patents

Description

  In the present invention, a panel on which a plurality of steel plates to be welded are transported on a backing device, and a welding machine travels along the welding line, thereby performing one-sided arc welding for performing automatic arc welding. Relates to the device.

  The single-sided welding device abuts the side ends of a pair of welded steel plates and arranges a backing device below the butt welding line to prevent the molten metal from dripping and travel along the welding line. A butt welding line is welded from one side by a welding machine (Patent Document 1). In this single-side welding device, a flux backing device and / or a copper plate backing device are provided so as to extend in one direction, and a panel on which a plurality of steel plates to be welded are temporarily attached on the backing device. It is conveyed and arranged so that its weld line coincides with the backing device. And from the welding machine that runs on the welding machine beam parallel to the backing device provided on the backing device, the torch is directed to the vicinity of the weld line, the welding wire is sent from this torch, and an arc is formed, By running the welder on the welder beam, the arc is moved along the weld line to weld the groove.

  That is, a welding machine is arranged above the groove of the temporarily welded steel plate in the panel, and a welding wire is sent out from one or a plurality of torches of the welding machine, and between the welding wire and the steel plate to be welded. By applying a voltage to the arc, an arc is formed from the tip of the welding wire toward the groove portion of the steel plate to be welded, and the arc heat causes the welding wire and the groove portion of the steel plate to be welded to melt. The groove is melt-bonded by moving the welder along the weld line and moving the arc along the weld line. At this time, a welding current flows between the welding wire and the steel plate to be welded due to arc formation. For this reason, it is necessary to collect the ground current of the welding current from the steel plate to be welded. Conventional ground current collecting methods include the following.

  First, there is a method in which a ground cable is directly connected to the welded steel plate. In this case, the ground cable is connected to the welded steel plate by a vise every time the panel is conveyed. There is also a method of connecting a ground cable of a welding power source to a support device that supports a steel plate to be welded. Further, there is a method of providing a plurality of ground current collectors on the steel plate support device. In order to cope with the case where the steel plate to be welded is conveyed by a roller, this earth current collector is to contact the steel plate to be welded by moving the current collecting contact toward the steel plate to be welded with a hydraulic cylinder or the like. It is.

  In addition, although it is not a thing of a single-sided welding apparatus, the technique which connected the ground terminal to the to-be-welded steel plate is described in patent document 2. FIG.

Japanese Patent No. 3539886 Japanese Utility Model Publication No. 50-53430

  However, the ground current collector has the following problems. First, the welding arc state becomes unstable due to the current collecting position of the ground. The state of the arc changes depending on whether the current collecting position is the welding start side, the welding end side, or the intermediate position. This phenomenon is generally referred to as magnetic blowing, and this phenomenon is particularly noticeable when the welding current is a direct current. For this reason, a good weld bead cannot be obtained.

  This magnetic blowing phenomenon is caused when the current path becomes more than one on the welded steel sheet, and the magnetic field generated in each current is repelled or attracted so that the arc does not go straight to the welded steel sheet. To do. The steel plates to be welded before welding are merely connected by a tacking portion that is dotted in the weld line direction at the groove. For this reason, it is unpredictable which direction the earth current will flow through which steel plate to be welded. Since the current flowing in the arc is orthogonal to the direction and direction of the current flowing through the welded steel plate, the arc receives an electromagnetic force in a direction perpendicular to the arc direction by the current flowing through the welded steel plate. For this reason, if the path of the current flowing through the steel plate to be welded is not stable, the arc is not directed in a desired direction and becomes unstable.

  Also, if the contact between the current collector and the steel plate to be welded is unstable, the arc state becomes unstable, and a spark is generated at the contact portion with the steel plate with unstable contact. Occurs.

In particular, when connected directly grounding cable to steel plates to be welded, when the welding current is large, the ground cable becomes heavy, whenever exchanging panel to attach the ground cable, the task of or removal is complicated. In addition, if the user forgets to remove the ground cable when replacing the panel, an unexpected accident will occur in which the cable is cut. Furthermore, if the size of the steel plate to be welded changes, the ground attachment position also changes, so it is necessary to carry a heavy cable to a new attachment position each time.

  In addition, the method of connecting the ground cable of the welding power source to the supporting device that supports the steel plate to be welded has the following problems. The steel plate support device receives the steel plate by a support such as a plurality of rollers or a support base, and the ground current returns from the steel plate to be welded to the power source through the support. The welded steel plate is not in close contact with or in contact with the steel plate support device at all support points, and the contact points are non-uniform due to the bending of the steel plate and the non-uniform support height of the support. Further, during welding, the welded steel plate is distorted by welding heat, and the contacted part may be separated during welding to generate sparks. Further, when the contact point moves, a good current collection state may be lost and magnetic blowing may occur. In particular, when the steel plate to be welded is thin and the mass per unit area is light, all the above-described problems may occur. Furthermore, when the steel plate to be welded is supported by the roller, the ground current flows through the bearing in the roller, which may damage the bearing. When the load applied to the bearing is large, the current passage resistance is small. However, when the load is small, the passage resistance increases and damage is promoted.

  Further, the method of providing a plurality of ground current collectors on the steel plate support device has the following problems. In the current collector, it is said that so-called pre-grounding provided at the end of the weld line is preferable for suppressing magnetic blowing. That is, the earth current collecting contact is brought into contact with a position where welding in the welded steel plate proceeds. However, even if the current collector contact of the current collector is brought into contact with the weld line end position, the weld line end position may not be accurately determined depending on the size and placement of the steel plate to be welded. Therefore, when the position where the current collecting contact comes into contact is closer to the end position of the welding line of the steel plate, even if welding can be performed up to that position, after passing through the contact position of this current collecting contact Does not necessarily prevent magnetic blowing from occurring in the welding arc. In addition, as described above, the current collector mechanism presses the current collecting contact against the steel plate to be welded with a hydraulic cylinder or the like. The steel plate is lifted up, and the contact pressure of the current collecting contact with the welded steel plate is not sufficiently transmitted, resulting in contact failure.

  The present invention has been made in view of such problems, and when collecting the arc current, magnetic blow does not occur, and there is no contact failure between the current collector and the welded steel plate during current collection. An object of the present invention is to provide a single-sided arc welding apparatus that does not occur and is easy to collect current.

A single-sided arc welding apparatus according to the present invention includes a backing member extending in one direction, and a steel plate to be welded that is arranged on the backing member in a plurality in the longitudinal direction of the backing member at a side portion of the backing member. A plurality of magnetically adsorbing members that are magnetically adsorbed and restrained; a torch that moves along a welding line of the steel plate to be welded and sends out a welding wire; A welding power source for generating an arc between them, and connecting each magnetic adsorption member and the ground terminal of the welding power source so that the ground current returns to the welding power source via the magnetic adsorption member. The magnetic blow is prevented .

In this single-side arc welding apparatus, the magnetic attraction member, on both sides of the backing member are each a plurality arranged in a longitudinal direction of the backing member, magnetic attraction member is ground terminal of the welding power source of the whole hand It is preferable that it is connected to.

  In the present invention, a plurality of magnetic adsorption members arranged on the side of the backing member are used for fixing the steel plate to be welded, and a current for releasing the ground current from the steel plate to be welded and returning it to the welding power source. Also used as a route. Since a plurality of magnetic adsorption members are arranged in the longitudinal direction of the backing member, the welding current is always the so-called pre-ground, and a stable arc is always obtained and high-quality welding without arc fluctuation is possible. It becomes. In addition, since the magnetic attracting member magnetically attracts the welded steel plate, the contact points of both are surely brought into contact with each other, and current conduction does not become unstable, so that a stable arc can be obtained.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a single-sided arc welding apparatus according to an embodiment of the present invention, FIG. 2 (a) is a plan view showing the magnetic adsorption device, (b) is a front view, and FIG. It is a perspective view which shows arrangement | positioning of a backing device and a magnetic adsorption apparatus. As shown in FIG. 3, the backing device 20 includes two rows of backing members in which a flux backing member 21 and a copper plate backing member 22 are provided in parallel. One of the flux backing member 21 and the copper plate backing member 22 is selectively used by a welding method. A plurality of magnetic adsorption members 29 are arranged in a line between the flux backing member 21 and the copper plate backing member 22, and the panel supplied on the backing device is magnetically coupled. It can be fixed so that it cannot be lifted by suction. In the vicinity of each magnetic attracting member 29, the roller 10 is arranged with its rotation axis perpendicular to the longitudinal direction of the backing members 21, 22, and the welded steel plates 1, 2 of the panel conveyed thereon It rolls to the lower surface of (refer FIG. 1), and supports this to-be-welded steel plates 1 and 2. As shown in FIG. Further, on the outside of the two rows of the flux backing member 21 and the copper plate backing member 22, rollers 23 and 24 are respectively installed with their rotation axes orthogonal to the longitudinal direction of the backing members 21 and 22. The rollers 23 and 24 are rotationally driven by motors 25 and 26, respectively, so that the panel can be moved in the longitudinal direction of the backing members 21 and 22. Further, between the adjacent rollers 23 and between the adjacent rollers 24, magnetic attracting members 27 and 28 are arranged, respectively, and like the magnetic attracting member 29, the panel is attracted and fixed by magnetic force.

  In the roller device 30, a plurality of rollers 31 are arranged along the longitudinal direction (panel transport direction) of the backing members 21 and 22. Each roller 31 is arranged so that the rotation axis thereof is orthogonal to the longitudinal direction of the backing members 21 and 22, and is rotated by the motor 32 to move the panel in the longitudinal direction of the backing members 21 and 22. Can do.

  FIG. 1 is a cross-sectional view in a direction perpendicular to the longitudinal direction of the backing members 21 and 22. The flux backing member 21, the copper plate backing member 22, the magnetic adsorption member 29, and the rollers 23 and 24 are mounted on one carriage 14, and a plurality of such carriages 14 are arranged, A backing member (flux backing member 21 or copper plate backing member 22) is disposed below the welding line, and a plurality of welding lines can be welded simultaneously by a plurality of welding machines.

  FIG. 1 shows a case where welding is performed using a flux backing member 21, and a panel temporarily attached with the steel plates 1 and 2 to be welded is conveyed onto these backing devices. The side edge portions of the welded steel plates 1 and 2 are abutted against each other, a groove is formed at the abutting end portion, and a welding line 3 extending perpendicularly to the paper surface of FIG. 1 is formed. The groove portion is tack welded, and a plurality of tack portions are dotted along the weld line. The panel is conveyed so that the weld line 3 is positioned on the flux backing device 21. A welder (not shown) is disposed on the weld line 3 so that the welder travels along the weld line 3 on a welder beam (not shown). And from the welding machine, the torch 4 extends downward, and its tip is positioned directly above the welding line 3. A welding wire 5 is fed from the torch 4 toward the groove, and an arc is formed by applying a voltage from the welding power source 6 between the welding wire 5 and the steel plates 1 and 2 to be welded. The

  The flux backing member 21 mounted on the carriage 14 spreads and stores the flux in the toy. By pressing this flux against the groove lower surface, the molten metal at the time of welding is stored. Prevent dripping. An air hose 15 is disposed at the lower portion of the flux backing member 21. By supplying compressed air to the air hose 15, the air hose 15 expands, and the flux backing device 21 on the air hose 15 is provided. The upper surface of the welded steel plates 1 and 2 is pressed against the lower surface of the groove portion. On the other hand, the air hose 15 is also arranged in the copper plate backing device 22. Similarly, when compressed air is supplied to the air hose 15, the air hose 15 swells and the copper plate backing device 22 is connected to the welded steel plates 1 and 2. It is designed to be pressed against the lower surface. Below these flux backing device 21 and copper plate backing device 22, a collecting member 16 such as a flux after use is disposed.

  The flux backing member 21, the magnetic adsorption member 29, and the copper plate backing member 22 are mounted on a carriage 17, and the carriage 17 runs on the carriage 1 in a direction perpendicular to the longitudinal direction of the backing member. can do. Therefore, the positions of the flux backing member 21, the magnetic attracting member 29, and the copper plate backing member 22 can be finely adjusted as the carriage 17 moves.

  In the magnetic adsorption member 29, the base 13 is installed on the carriage 17, the support portion 18 is fixed on the base 13, and the magnetic adsorption member 29 is fixed on the support portion 18. Yes. The magnetic attracting member 29 has an electromagnetic magnet, and by energizing the electromagnetic magnet, the magnetic attracting member 29 attracts the upper panel, that is, the welded steel plates 1 and 2, and restrains the welded steel plates 1 and 2. It is supposed to be. When the electromagnetic magnet is not energized, as shown in FIG. 2B, the distance x between the upper common tangent line (indicated by a two-dot chain line) of the pair of support rollers 10 and the magnetic attracting member 29, that is, a pair of The magnetic attracting member 29 is positioned below the common tangent so that the distance x between the lower surfaces of the steel plates 1 and 2 to be welded supported on the support roller 10 and the magnetic attracting member 29 is about 10 mm. When the electromagnetic magnet is energized with the steel plate to be welded positioned above the magnetic attracting member 29, the magnetic attracting member 29 is guided by the guide bolt 40 and is attracted to the steel plate to be welded. The amount of jumping is limited to, for example, 12 mm by the guide bolt 40. Therefore, even if the welded steel sheet is lifted further due to thermal strain or the like, the magnetic adsorption member 29 is clamped to deform and deform the welded steel sheet. Limit lifting. As a result, even when the backing member is pressed against the lower surface of the groove portion of the welded steel plate and an upward force is applied to the welded steel plate, the welded steel plate does not rise. Further, by fixing the steel plate to be welded by the magnetic adsorption member 29, it is possible to correct the bending of the steel plate and prevent the bending and movement of the steel plate due to distortion during welding.

  Such a magnetic attracting member 29 is disposed between the flux backing member 21 and the copper plate backing member 22, and a plurality of magnetic attracting members 29 are arranged in the longitudinal direction of the backing member. A plurality of magnetic attracting members 27 and 28 having the same configuration as the magnetic attracting member 29 are also disposed in the vicinity of the rollers 23 and 24 disposed outside the backing members 21 and 22. Therefore, the above-mentioned magnetic attracting members 29, 27, 28 are arranged on both sides of each backing device 21, 22.

  In the present embodiment, the ground terminal of the welding power source 6 is connected to all these magnetic attracting members 29, 27 and 28. As shown in FIG. 3, each magnetic adsorption member 29 or the like has a plate-like connection terminal 12 standing on the base 13, and the connection terminal 12 and the magnetic adsorption member 29 and the like are connected to the cable 11. Connected by. The ground terminal of the welding power source 6 is connected to an iron base such as the welding carriage 14 or the welding carriage 17 via a cable, and since the connection terminal 12 is fixed to the base, the connection terminal 12 is also connected to the welding power source 6. Is connected to the ground terminal. Accordingly, the magnetic attracting member 29 and the like are connected to the ground terminal of the welding power source with the connection terminal 12 as a relay point.

  Next, the operation of the single-sided arc welding apparatus configured as described above will be described. When the panel is conveyed to the arrangement position of the backing device, the position of the weld line 3 between the welded steel plates 1 and 2 is positioned so as to be located immediately above the backing member 21 or 22. If necessary, the carriage 14 moves to adjust the position, and the carriage 17 moves to finely adjust the position. And it supplies with electricity to the magnetic adsorption member 29 grade | etc., And the to-be-welded steel plates 1 and 2 are magnetically adsorbed and restrained. Thereby, the to-be-welded steel plates 1 and 2 contact the magnetic adsorption member 29 grade | etc.,. In this case, since the steel plates 1 and 2 to be welded are magnetically attracted to the magnetic attracting member 29 and the like, they are reliably in electrical contact with each other. Next, compressed air is supplied to the air hose 15 of the flux backing device 21 below the welding line 3, the air hose 15 expands, and the flux backing device 21 is pressed against the groove lower surfaces of the welded steel plates 1 and 2. Thereafter, when a voltage is applied between the welding wire 5 fed from the torch 4 and the groove of the steel plates 1 and 2 to be welded, an arc is generated, an arc current flows, and welding is performed. The supply current from the welding power source 6 becomes an arc current from the welding wire 5 and enters the welded steel plates 1 and 2, flows from the welded steel plates 1 and 2 to the magnetic adsorption members 29, 27 and 28, and is welded via the gantry. Return to power supply 6. That is, the ground current is returned to the welding power source 6 through the magnetic adsorption member 29 and the like. Then, when the welding machine is run along the welding line 3 and the welding wire 5 is moved along the welding line 3, the welding wire and the steel plate to be welded and the solidification of the weld metal are continuously performed in the welding direction, Single-sided arc welding is performed.

  In this case, a large number of magnetic attracting members 29, 27 and 28 are arranged along the weld line 3 on both sides of the weld line 3. For example, when the flux backing device 21 is used, the magnetic attracting members 29 and 27 are positioned in the vicinity of both sides of the welding line 3, and when the copper plate backing device 22 is used, in the vicinity of both sides of the welding line. The magnetic attracting members 29 and 28 are located. As described above, since a large number of magnetic attracting members are arranged on both sides of the weld line along the weld line 3, the ground current that enters the welded steel sheet from the arc point always flows through the front magnetic attracting member 29 and the like. Since it returns to the welding power source, it is always a so-called front ground, and no magnetic blow occurs. Since the magnetic attracting member 29 and the like are reliably in contact with the lower surface of the steel plate by the magnetic force, the contact state is also good, and the contact state is not deteriorated due to distortion of the steel plate during welding, and the ground current is reliably ensured. It flows through the magnetic adsorption member. Therefore, the current path does not fluctuate and arc deflection is prevented. Note that the earth current may flow only in the row of the magnetic attracting members 29 between the two types of backing devices 21 and 22.

  The magnetic blowing phenomenon is particularly noticeable when the welding current is a direct current, and when the welded steel plate is only temporarily attached, the current path becomes unstable and becomes remarkable. Therefore, the present invention is particularly useful in single-sided welding, particularly when the preceding first electrode uses a direct current and a flux backing member is used as the backing member.

It is sectional drawing of a perpendicular direction to the backing member which shows the single-sided arc welding apparatus which concerns on embodiment of this invention. Similarly, it is a figure which shows the magnetic adsorption member of the single-sided arc welding apparatus of this embodiment, (a) is a top view, (b) is a front view. It is a perspective view which shows arrangement | positioning of the backing member and magnetic adsorption member of the single-sided arc welding apparatus of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2: Steel plate to be welded 3: Welding wire 4: Torch 5: Welding wire 10, 23, 24: Roller 11: Cable 12: Connection terminal 13: Base 14, 17: Carriage 15: Air hose 16: Collection member 20: Backing device 21: Flux backing device 22: Copper plate backing device 27, 28, 29: Magnetic adsorption device

Claims (2)

A plurality of backing members extending in one direction, and a plurality of steel plates that are arranged in the longitudinal direction of the backing member at the side of the backing member and are magnetically attracted and restrained on the backing member A magnetic attraction member, a torch that moves along a welding line of the steel plate to be welded and sends a welding wire, a welding power source that feeds the welding wire and generates an arc between the welding wire and the steel plate to be welded, And connecting each of the magnetic adsorption members and the ground terminal of the welding power source so that the ground current is returned to the welding power source via the magnetic adsorption member to prevent magnetic blowing. One-sided arc welding equipment characterized. The magnetic attraction member, on both sides of the backing member are each a plurality arranged in a longitudinal direction of the backing member, that magnetic attraction members of all hand are connected to the ground terminal of the welding power source The single-sided arc welding apparatus according to claim 1, wherein

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