JPH0555232B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a welding device that automatically welds the corners of welded box-shaped members such as box-shaped columns and box-shaped beams that are often used in steel structures. .

Prior Art Box-shaped cross-section members such as box-shaped columns and box-shaped beams are often used in steel structures. This type of member is made by assembling four long thick steel plates into a box shape, installing a diaphragm inside with appropriate gaps, and continuously welding the four corners using submerged arc welding, MAG welding, etc. Manufactured by. The submerged arc welding method will be explained below.

By the way, such a box-shaped cross-sectional member is a product that is produced in a wide variety of small quantities and has different dimensions depending on the structure, and is also a so-called heavy and long product, so there are various difficulties in automating it.

Currently known automatic welding equipment for thick-walled box-shaped cross-sectional structural members has a work area before and after the welding area, the work to be welded is set on a frame fixed at the welding area, and the workpiece is placed in parallel with the welding area. A movable welding device is placed on the running rail that has been laid, and the welding device has two
The welding electrodes are arranged in tandem in the running direction of the welding equipment, and the welding equipment is moved at a predetermined speed while the welding electrodes are placed along the welding line of the workpiece, and a thick box-shaped structural member is welded in one pass. There are devices that automatically weld corners on one or both sides.

Although this device enables fully automatic welding of box-shaped cross-sectional structural members with considerable thickness, it still has the following problems.

(b) In order to achieve complete penetration of the corners of the workpiece, for example, if the plate thickness is about 40 mm, it is necessary to flow a total current of about 3000 A, but the welding power source is heavy. Larger, for example, 1500A
The weight of this product reaches approximately 1 ton, and it is difficult to load the required number of these onto a traveling trolley together with welding equipment.
This is not a good idea as the running weight will increase and the power required for movement will also increase. Therefore, in this device, the welding power source is a stationary type, and the welding head and
A traveling trolley equipped with a welding device consisting of welding wire and a control/operation panel, withstanding the welding current used,
In addition, they are connected by multiple welded cables of a length that does not hinder the movement of the trolley. Welding cable is
Although it is supported by cable hangers, cable carriers, etc., the welding cable is severely damaged.
Furthermore, when welding cables are connected in parallel, the current cannot be divided equally to each cable, and cables with extra current capacity are required.

(b) Since the welding wire is mounted on a traveling trolley,
The weight is limited to 75 to 150 kg per electrode. This type of wire requires frequent replacement when continuously welding thick plates.

(c) From the viewpoints of (a) and (b) above, the plate thickness that can be welded in one run is limited to approximately 50 mm.

(d) Since this device performs welding by setting the workpiece to be welded on a pedestal next to the running rail, it is not suitable for continuous production by incorporating it into a production line.

Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned problems of conventional automatic welding devices for thick-walled box-shaped cross-sectional structural members. It is possible to continuously weld the corners of shaped cross-sectional structural members, and (b) it is possible to stably and rationally flow current to the welding equipment from the welding power source necessary for welding extremely thick walls. It is an object of the present invention to provide a welding device that causes less damage to the conductor that carries the welding current (c) requires less frequent replacement of the welding wire, and (d) as a result, is capable of one-run welding of extremely thick plates, for example, 50 mm or more. Take it as a challenge.

Means for Solving the Problems In order to solve the above-mentioned problems, the automatic welding device for corner joints of thick-walled box-shaped cross-sectional structural members of the present invention has the following features: , a pedestal having a floor, a conveying means provided under the floor of the pedestal, on which the object to be welded is placed with the surface including the two joints facing upward, and can be conveyed in the longitudinal direction; provided below the floor and on both sides of the conveying means symmetrically with respect to its center line;
three or more welding electrodes arranged in a line on a straight line parallel to the conveying direction of the conveying means, a sensor for copying the actual object to be welded, and the vertical direction, arrangement direction, and direction of each of the welding electrodes. a pair of welding heads each having a perpendicular horizontal position adjustment means, a positioning means for positioning the welding head based on the detection output of the copying sensor, and each of the welding electrodes fixed on the floor of the pedestal. It has a welding wire and a welding power source corresponding to the above, and is characterized in that the welding power source and the electrode are connected by a good electrical conductor such as a copper strip or a copper ribbon wire.

(b) In a second invention, in place of the last configuration of the first invention, a current collecting ground plate is provided on the conveying means, and the moving side end of the ribbon bear is connected to this,
It is characterized in that its fixed end is connected to one end of the welding power source output terminal on the pedestal via a good electrical conductor such as a copper strip or a copper ribbon wire.

(C) A third invention provides, in place of the last configuration of the first invention, a welding head control means, which controls the welding head after welding arcs are generated in all of the welding electrodes of the target welding head during welding. Welding is started by transporting the workpiece at a predetermined speed, and if the welding voltage of the target welding electrode continues to decrease after a certain period of time, welding by the welding head including that electrode is stopped. It is characterized by control.

(d) In place of the last configuration of the first invention, the fourth invention detects the end of the workpiece by a sensor for tracing the actual workpiece provided in the welding head, and a predetermined period of time has elapsed after the sequential detection. After that, the target welding electrode is pulled upward for a predetermined period of time, and then welding is stopped.

Effect: According to the common feature of the above four inventions, the welding head including the welding electrode, the spot copying sensor, and the welding electrode position adjustment means, the welding wire, and the welding power source are all located at a fixed position on the production line. Since it is mounted on a fixed frame, it is easy to connect the welding power source and the welding head, and it is possible to pass a large current. Therefore, three or more electrodes are installed on one side of the head and welding is performed. By arranging them in tandem in the direction of the wire, it is possible to weld extremely thick steel plates of 50 mm or more in one run.The welding head is installed on a fixed frame, so the welding wire weighs, for example, 1000 kg. There is no problem even if the welding wire becomes larger, and therefore, even when extremely thick steel plates are continuously welded, the frequency of replacing the welding wire can be reduced.

The pedestal on which the welding equipment is mounted has a floor, below which is provided a transport means such as a trolley or conveyor that can transport the workpiece in the longitudinal direction, and welding heads are provided on both sides symmetrically with respect to the center line. Therefore, the corners on both sides can be simultaneously welded in one run while moving the object to be welded in the longitudinal direction. Therefore, the welding object conveying means can be incorporated into a production line for thick-walled box-shaped cross-sectional structural members, making continuous production possible.

The welding heads installed on the pedestal on both sides of the welding object conveying means are positioned by the detection output of the spot copying sensor, so the electrode position of the welding head can be aligned with the welding line of the welding object of various cross-sectional dimensions. This makes it possible to continuously and properly weld the corners of box-shaped cross-sectional structural members produced in small quantities in a wide variety of ways.

Furthermore, according to the feature of the first invention, since the welding head is installed on a stand on which the welding power source is fixed, there is no need to use a cable for connection, and a good electrical conductor such as a copper plate and a copper ribbon wire are connected. Because it can be used, a larger current can flow through a smaller cross-sectional area than a cable, and it is less likely to be damaged. Minor positional adjustments of the welding head and welding electrode can be made without difficulty by using the ribbon wire.

According to the feature of the second invention, a current collecting ground plate is provided on the object conveying means such as a cart or a conveyor, and the moving side end of the ribbon bear is connected to this, and the fixed end is connected to the welding power output terminal on the frame. Since it is connected to one end of the welding material through a good electrical conductor, such as a copper plate, it is possible to reliably and smoothly ground the welding power source from the welding object being welded while moving.

According to the feature of the third invention, since the welding head control means is provided to control the start and stop of welding as described above, welding starts after arcs are emitted from all three or more electrodes. If the conductor wires are short-circuited and the voltage drops abnormally, welding will be stopped, thereby preventing welding defects and accidents.

According to the fourth invention, the end of the welded object is detected by the spot copying sensor, and after each predetermined time elapses, the plurality of capacitive electrodes are sequentially pulled upward for a predetermined time, and then welding is stopped. , the multiple electrodes arranged in a tidem are pulled upwards in sequence starting from the end, and welding is stopped after a sufficient distance has passed, so there is no risk of a large amount of molten metal instantly solidifying and welding the electrodes. .

Embodiments Below, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the overall configuration of an automatic welding apparatus for a thick box-shaped cross-sectional structural member according to an embodiment of the present invention.

The welding device is mounted on a pedestal 3 that supports a floor 2 with a plurality of pillars 1 fixed to the ground at a fixed position on a production line. On the ground below the floor 2 of the pedestal 3, three parallel rows of volume transport paths are provided. In FIG. 1, the conveyance path 4 on the right side is used for carrying in the welded objects assembled in a U-shape and temporarily attached, and a roller conveyor 5 is used as a conveying means. The central conveyance path 6 is a conveyance path for automatically welding the workpiece while moving it in its longitudinal direction. Moving. The conveyance path 8 on the left side is for carrying out the welded object, and a roller conveyor is used as the conveyance means.

Between the back side of the carry-in conveyance path 4 and the welding conveyance path 6, and between the welding conveyance path 6 and the front side of the carry-out conveyance path 8, there is a welded object lateral movement means (not shown) such as a traverser. Also, a welding conveyance path 6 is provided.
A reversing device (not shown) for reversing the workpiece to be welded upside down is provided at either end.

A welding head for simultaneously welding both upper corners of the welded object transported at a constant speed through the capacitive transport path 6 in one run was provided approximately in the center of the floor of the frame 3. In the diagram of the large opening 9, the box-shaped girder 13 (fourth
(see figure) and is provided below the floor 2. Therefore, it is not visible in Figure 1.

Therefore, FIGS. 2, 3, and 4 show a perspective view, a front view, and a side view of the welding head.

A welding head 12 is fixed to a box-shaped garter 13 provided under the rear edge of the opening 9 in the floor 2 of the frame 3 in FIG. A guide rail 1 is installed in parallel on the upper surface and lower part of the front of the box-shaped garter 13.
4 and 15 are provided, and are engaged with a guide shoe 17 provided on the base plate 16 of the welding head 12 so as to be slidable and not fall off. As shown in FIGS. 2 and 3, a pair of guide rails 14, 15 and a welding head 12 are provided symmetrically with respect to the center line 18 of the rail 7 of the workpiece conveyance path 6. Each welding head board 16 is provided on the box-shaped garter 13 in parallel with the guide rail 14, and is screwed into a threaded rod 20 that rotates around its own axis by a motor 19 fixed to the box-shaped garter 13. A ball screw nut fixed to the base plate 16 allows it to be displaced left and right along the guide rails 14 and 15.

Two guide rails 2 are installed in the vertical direction on the board 16.
1 is fixedly installed, and an arm 23 is provided so as to be slidable thereon via a guide shoe 22.
The board 16 is provided with a threaded rod 25 that extends parallel to the guide rail 21 and rotates about its own axis by a motor 24 fixed to the board 16. The arm 23 is provided with a ball screw nut that is screwed onto the threaded rod 25, and by rotating the motor 24, the arm 23 is rotated.
3 is the guide rail 21 via the guide shoe 22
It is possible to go up and down along the

At the lower end of the board 16 is a sensor 26 for copying the actual object,
Sensors 27 for detecting the front and rear ends of the workpiece are provided.

The arm 23 has three welding electrodes 28, 29, 3.
0 are attached so that they are lined up in a row in the front-rear direction (direction of the weld line on the workpiece). Each electrode is connected to a left and right position adjustment motor 31 provided on the arm 23, respectively.
A motor 33 for adjusting the vertical position provided on the intermediate bracket 32 for attaching the welding electrode makes it possible to adjust the horizontal and vertical positions using the same mechanism as the displacement of the arm 23 described above. Furthermore, the second and third electrodes 29 and 30 can be displaced in the front and back direction via a threaded rod by a pole spacing adjustment motor 34 provided at the tip of the arm. The welding electrodes 28, 29, and 30 can be adjusted to the spacing in the front-rear direction so that the heights of the tips are aligned in a straight line. A pair of feed rollers 36 rotated by a welding wire feed motor 35 are provided at the upper end of each electrode, and the welding wire fed from the welding wire bobbin is sent through the electrode to the welding area.

Although not shown in the figure to avoid clutter,
The welding electrode is attached to a bus bar on the mounting bracket.
bar: thick copper plate, also called bus bar), and its power supply terminal is connected to a power supply conductor made of a copper plate, which will be described later, via a copper ribbon wire, so that there is no problem in adjusting the position of the electrode. has been done.

This welding device has a large cross-sectional dimension (for example, 1,000 mm x 1,000
mm) to small cross-sectional dimensions indicated by 41 (e.g. 400 mm)
It is now possible to weld the corners of workpieces with various dimensions between When detected, 2 of the workpiece to be welded
The position of the two welding lines is detected by the actual copying sensor 26, and the detection output signal causes the motors 19, 2 to move.
4 to control the vertical, horizontal, and horizontal positions of the arm 23.
Move the welding electrode so that it matches the welding line of the workpiece.

Referring again to FIG. 1, the welding wire bobbins 42 to be fed to the six welding electrodes on both sides are installed on both sides of the opening 9 provided just above the position where the welding head 12 is attached. ing. Since the wire bobbin 42 is placed on the fixed pedestal 3, it is not subject to weight restrictions and must be replaced frequently even when continuously welding two corners of an extremely thick box-shaped cross-section member at the same time. There will be no need.

Welding power sources 43 are also arranged on the floor 2 of the pedestal 3. In addition, the figure shows the main features of the present invention,
Only the bottom of the welding power source is shown so that the conductor from the welding power source to the welding electrode is clearly shown in the figure. For example 80
If welding a workpiece with a thickness of up to m/m in one run, the amount of current that should be applied to the three welding electrodes is, for example, 2800 A for the leading electrode, 2200 A for the middle electrode, and 2200 A for the trailing electrode.
1800A, a total of 6000~7000A large current amount. Even if two welding power sources are provided for each electrode, the amount of current per one is about 1500A, which is similar to conventional methods.
If power is to be supplied using cables, a large number of cables will be required, and cable hangers and the like will be required for the wiring, which will also increase space. In the present invention, the welding head is also provided on the same frame as the welding power source, and the distance between the two does not change, so the copper plate 44 is used as a power supply conductor from the welding power source 43 to the welding head 12. However, as mentioned above, the welding head and electrode need to be slightly adjusted in position according to the dimensions of the workpiece, so a ribbon wire is interposed between the stationary object and the busbar to which the electrode is attached. displacement is allowed.

Copper plates and ribbon wires not only can carry incomparably more current than cables in the same cross-sectional area, but they are also less susceptible to damage.

In FIG. 1, reference numeral 45 is a control panel, 46 is a switch panel, 47 is a conveyor for collecting flux from the welded part, 48 is a flux hopper, 49 is a flux shoot that sends the collected flux to the flux hopper 48, and 50 is a flux chute. This is a slag receiver that collects the slag separated from the slag.

By the way, when performing arc welding, it is necessary to ground the welding power source from the object to be welded, but in the welding device of the present invention, the welding power source is fixed on a fixed frame, and the object to be welded cannot be moved. Welding is performed while Therefore, in the apparatus of this embodiment, as shown in FIG.
A ribbon bear, for example, 4 strips (not shown) of 1 mm x 100 mm of rectangular copper wire, which are unrolled along the strip, is provided, and the moving side end is connected to a current collecting ground plate fixed to a carriage for transporting the workpiece. However, the fixed end of the ribbon bear is connected to one end of the welding power output terminal on the pedestal 3 via a copper plate. Needless to say, the object to be welded is appropriately connected to the current collecting arm plate on the conveyance truck.

Now, in the welding apparatus of this embodiment, three welding electrodes are arranged in tandem in the direction of the welding line on one welding head, and all the electrodes weld an extremely thick steel plate in one run. If the welding voltage of each electrode during welding is less than the predetermined voltage, the workpiece to be welded should be transported at a predetermined speed only after arcs are normally generated from all electrodes. To prevent this from occurring, it is necessary to stop welding using the welding head that includes the welding electrode. Therefore, when welding, the welding current of the welding electrode of the target welding head is 200A or more, the workpiece is transported at a predetermined speed, welding is started,
After seconds have elapsed, if the welding voltage of the target welding electrode remains below 10V for 1 second or more continuously, it is appropriate to control the welding head including that electrode to stop welding.

Also, when welding extremely thick steel plates of, for example, 80 mm in one run using three electrodes at the same time like this welding device, a large amount of weld metal is formed in the welding area, so it is necessary to stop them all at the same time. Then, unsolidified weld metal gathers and solidifies, causing problems such as the electrode becoming stuck. Therefore, in order to prevent such problems, when the end of the workpiece is detected by the front and rear end detection sensor 27 of the workpiece provided in the welding head 12, the welding electrode is moved to a predetermined position after a predetermined time has elapsed. It is preferable to control the welding so that the welding is stopped after the welding is pulled upward for a certain amount of time.

Effects As described above, according to the present invention, by simultaneously welding using three or more electrodes arranged in tandem while fixing the welding equipment and transporting the workpiece, welding can be performed on extremely thick copper sheets as thick as 80 mm in one run. This makes it possible to use copper plates and copper ribbons as conductors between the welding power source and the welding electrode, which is much more advantageous than conventional methods in terms of cost and space. Furthermore, it becomes easy to provide welding heads on both sides of the conveyance path of the workpiece, and it is possible to simultaneously weld two corners of a thick box-shaped structural member.

Further, by using a ribbon bear as a grounding means for the object to be welded, there is no need to extend and contract a long conducting wire.

Further, since the welding current of the welding electrode and the welding voltage after welding is started are detected to control the start and stop of welding, accidents are prevented from occurring.

Furthermore, by sequentially pulling up the plurality of electrodes at the end of welding, welding of the electrodes can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a perspective view mainly showing the structure on the pedestal and the means for transporting the workpiece in accordance with an embodiment of the present invention, FIG. 2 is a perspective view showing the structure of the welding head, and FIGS. 3 and 4 respectively. FIG. 2 is a front view and a sectional view looking outward from the center of the configuration under the pedestal. 2... Floor of the pedestal, 3... Frame, 6... Workpiece conveyance path, 7... Rail, 9... Opening of the pedestal, 12
... Welding head, 14-24 ... Welding head position adjustment means, 26 ... Actual copying sensor, 28, 2
9, 30... Welding electrode, 31-35... Electrode position adjustment means, 40, 41... Work to be welded, 43... Welding power source, 44... Copper wire, 45... Control panel, 51...
...Guide rail.

Claims (1)

[Scope of Claims] 1. An automatic corner joint welding device for thick-walled box-shaped cross-sectional structural members, which comprises: a pedestal having a floor; 2. Place the object to be welded into the joint.
a conveyance means capable of conveying the conveyor in the longitudinal direction of the conveyor with the surface thereof facing upward; three or more welding electrodes arranged in a line in a straight line parallel to the conveying direction of the conveying means, a sensor for copying the actual object to be welded, and the vertical direction, arrangement direction, and perpendicular to the above-mentioned welding electrodes. a pair of welding heads each having a horizontal position adjustment means, a positioning means for positioning the welding head based on the detection output of the tracing sensor, and a positioning means fixed on the floor of the mount and corresponding to the welding electrode. A welding device comprising a welding wire and a welding power source, the welding power source and the electrode being connected by a good electrical conductor such as a copper strip or a copper ribbon wire. 2. An automatic welding device for corner joints of thick-walled box-shaped structural members, which is fixed at a fixed position on a production line, has a pedestal with a floor, is installed under the floor of the pedestal, and connects the object to be welded to two parts of the joint.
a conveyance means capable of conveying the conveyor in the longitudinal direction of the conveyor with the surface thereof facing upward; three or more welding electrodes arranged in a line in a straight line parallel to the conveying direction of the conveying means, a sensor for copying the actual object to be welded, and the vertical direction, arrangement direction, and perpendicular to the above-mentioned welding electrodes. a pair of welding heads each having a horizontal position adjustment means, a positioning means for positioning the welding head based on the detection output of the copying sensor, and a positioning means fixed on the floor of the pedestal and corresponding to the welding electrode. A welding wire and a welding power source are provided on the above-mentioned conveying means, and the moving end of the ribbon bear is connected to this, and the fixed end thereof is connected to one end of the welding power output terminal on the above-mentioned stand. A welding device characterized in that the connection is made through a good electrical conductor such as a copper strip and a copper ribbon wire. 3. An automatic corner joint welding device for thick-walled box-shaped cross-sectional structural members, the device is fixed at a fixed position on a production line, includes a pedestal with a floor, is installed under the floor of the pedestal, and connects the workpiece to two parts of the joint.
a conveyance means capable of conveying the conveyor in the longitudinal direction of the conveyor with the surface thereof facing upward; three or more welding electrodes arranged in a line in a straight line parallel to the conveying direction of the conveying means, a sensor for copying the actual object to be welded, and the vertical direction, arrangement direction, and perpendicular to the above-mentioned welding electrodes. a pair of welding heads each having a horizontal position adjustment means; a positioning means for positioning the welding head based on the detection output of the tracing sensor; It has a corresponding welding wire, a welding power source, and the above-mentioned welding head control means. Welding is started by transporting the workpiece at a predetermined speed, and if the welding voltage of the target welding electrode continues to decrease after a certain period of time, welding by the welding head including that electrode is stopped. A welding device characterized by controlling. 4. An automatic corner joint welding device for thick-walled box-shaped cross-sectional structural members, the device is fixed at a fixed position on the production line, has a pedestal with a floor, is installed under the floor of the pedestal, and connects the objects to be welded to two parts of the joint.
a conveying means capable of transporting the conveyor in the longitudinal direction of the conveyor with the surface thereof facing upward; three or more welding electrodes arranged in a line on a straight line parallel to the conveying direction of the conveying means, a welding object sensor and a welding object front and rear end detection sensor, and a vertical direction of each of the welding electrodes, a pair of welding heads each having a position adjustment means in the arrangement direction and a horizontal direction perpendicular thereto; a positioning means for positioning the welding heads based on the detection output of the copying sensor; fixed on the floor of the mount; , has a welding wire and a welding power source corresponding to each of the welding electrodes, detects the end of the workpiece by sensors for detecting the front and rear ends of the workpiece provided in the welding head, and a predetermined period of time has elapsed after sequentially detecting the end of the workpiece. The welding device is characterized in that the welding device stops welding after the target welding electrode is pulled upward for a predetermined period of time.