JP7261676B2 - On-site welding equipment - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to field welding equipment.

Patent Literature 1 describes an apparatus for automatically welding corners of welded joints of box structural members using a robot. This robot welds the side surface of the box structural material with a welding torch that is inclined at a predetermined angle, and when it reaches the corner located on the diagonal line of the box structural material, the welding is temporarily interrupted and the welding is performed. Retract the welding torch diagonally. Then, when the robot again approaches the welding torch to the adjacent surface of the side surface, the robot changes the posture of the welding torch so that it is inclined at the predetermined angle with respect to the adjacent surface.

JP-A-8-257745

As described in Patent Document 1, in the welding of the corners of the welded joint, when the welding torch is moved from one surface to the surface adjacent to the one surface, the welding is temporarily interrupted at the corners. Many methods are used to However, when welding is performed by arc welding, for example, due to temporary interruption of welding, corners are welded due to unstable arc discharge immediately after generation and immediately before disappearance, and welding defects such as poor fusion and blowholes are likely to occur. . As a result, the welding quality may deteriorate.

On the other hand, a method of changing the posture of the welding torch without interrupting welding at the corner and welding by continuous arc discharge is also conceivable. However, since the tip of the welding torch stays at the corner while the posture is changed, the weld metal adheres excessively to the corner, and problems such as dripping of the weld metal may occur. Therefore, in this case as well, the quality of welding may deteriorate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a field welding apparatus capable of suppressing deterioration in quality at corners.

A field welding apparatus according to the present invention includes a welding robot having a welding torch for arc welding, a corner, a first extension extending from the corner along a first direction, and a first extension extending from the corner along the first direction. a control unit for controlling the welding robot to weld a portion to be welded including a second extending portion extending along a second direction extending along a second direction, wherein the control unit is configured to A process of controlling the welding robot to move the welding torch in order of the first extension, the corner, and the second extension along, and moving the welding torch to the first extension, the corner, and the second a first state in which the tip of the welding torch intersects the first direction; a process of controlling the welding robot to sequentially change the orientation of the welding torch between a second state in which the groove of the corner is directly facing and a third state in which the tip of the welding torch intersects the second direction; , and controlling the welding robot to sequentially change the orientation of the welding torch, the welding torch moving along the first extending portion moves from the corner to the corner from a position separated by the first distance. The orientation of the welding torch is gradually changed from the first state to the second state until the welding torch reaches the corner, and the welding torch moving along the second extension is separated from the corner by the second distance from the corner. The orientation of the welding torch is gradually changed from the second state to the third state while moving away from the position.

In the on-site welding apparatus according to the present invention, the control unit that controls the welding robot controls the welding robot to move the welding torch along the extending direction of the welded portion, and during the movement of the welding torch, , a process of controlling the welding robot to cause the welding torch to continuously generate an arc discharge, and a process of controlling the welding robot to change the orientation of the welding torch. Further, the orientation of the welding torch is gradually changed while the welding torch moving along the first extending portion reaches the corner from a position separated from the corner by the first distance. The welding torch moving along the extension is gradually changed while moving away from the corner to a position a second distance away from the corner. As a result, the posture of the welding torch is slowly changed while the welding torch is being moved, thereby suppressing excessive adhesion of the weld metal to the corners. Therefore, deterioration of welding quality at the corner can be suppressed.

By the way, the groove cross-section at the corner is larger than the other groove cross-sections. Therefore, if the posture of the welding torch is changed without interrupting welding at the corner, the amount of the weld bead at the corner tends to be insufficient (so-called corner drop).

In the on-site welding apparatus according to the present invention, the process of moving the welding torch is performed during the time when the welding torch moving along the first extension reaches the corner from a position separated by the third distance from the corner. , retreat processing for retreating the welding torch in a direction away from the groove of the welded portion, and the welding torch moving along the second extension portion is moved away from the corner to a position a fourth distance away from the corner. , and an advancing process for advancing the welding torch by the amount retreated in the retreating process. In this case, since the position of the welding torch when the tip of the welding torch directly faces the corner is separated from the groove of the welded portion, a weld bead with a projecting shape is likely to be formed at the corner. Therefore, it is possible to suppress the angle drop of the weld bead.

Further, in the on-site welding apparatus according to the present invention, the control unit controls the welding robot to stop the movement of the welding torch for a predetermined time after changing the direction of the welding torch from the first state to the second state. and the orientation of the welding torch may be changed from the second state to the third state after the movement has been stopped for a predetermined time. In this case, the momentary stoppage of the welding torch movement ensures that there is a sufficient amount of weld metal in the corner. Therefore, it is possible to suppress the angle drop of the weld bead.

ADVANTAGE OF THE INVENTION According to this invention, the field welding apparatus which can suppress the deterioration of the quality in a corner can be provided.

FIG. 1 is a perspective view schematically showing a welding device according to one embodiment of the invention. 2 is a side view of the robot of FIG. 1; FIG. FIG. 3 is a block diagram showing a functional configuration of a control unit; 4A and 4B are diagrams for explaining the processing contents of the control unit, FIG. 4A is a plan view of a welded section, and FIG. 4B is a diagram showing an example of a cross-sectional view of a groove. FIG. 5(a) is a schematic plan view for explaining an operation pattern, and FIG. 5(b) is an enlarged view showing a part of FIG. 5(a). FIG. 6 is a flow chart showing the procedure of on-site welding processing. 7(a) and 7(b) are plan views of the welded section for explaining the sensing position. FIG. 8 is a flow chart showing the procedure of bus allocation processing. FIG. 9 is a sectional view of the bevel for explaining the bus allocation process. FIG. 10 is a flowchart showing the procedure of robot welding processing.

An embodiment will be described below with reference to the drawings. In the description of the drawings, the same elements or corresponding elements are denoted by the same reference numerals, and redundant description may be omitted.

[Welding equipment]
The configuration of the welding device 1 will be described with reference to FIGS. 1 and 2. FIG. The external shape of objects to be welded (for example, two column parts 3) to which the welding apparatus 1 shown in FIG. 1 is applied is, for example, a square shape. The object to be welded includes four side surface portions Ws (first plane portion, second plane portion) and four corner portions Wc (intersection portions). Each of the four side surface portions Ws is formed flat, and two adjacent side surface portions Ws among the four side surface portions Ws intersect (perpendicularly) with each other at the corner portion Wc. The welding device 1 is a field welding device for welding, for example, column parts 3 as objects to be welded at a construction site of a building.

The column component 3 is, for example, a rectangular steel pipe, and a rectangular steel pipe column is constructed by stacking a plurality of column components 3 in the vertical direction and welding them together. The column parts 3 to be welded are arranged so that their horizontal ends are brought close to each other over the entire circumference and opposed to each other. The portion where these ends face each other is the welded portion W to be welded by the welding device 1, and the groove of the welded portion W extends over the entire circumference of the column component 3 (that is, all the side portions Ws across) extends in the horizontal plane. Below, among the column components 3 to be welded together, the lower column component 3A and the upper column component 3B.

The column parts 3A and 3B are each provided with an erection (a first erection and a second erection) so as to straddle the groove of the welded portion W. As shown in FIG. The erection has an erection piece 5 welded to the central portion of each side surface of each column component 3A, 3B in the vicinity of the welded portion W, and an erection jig 7. As shown in FIG. An erection piece 5 provided on the column component 3A and an erection piece 5 provided on the column component 3B are arranged vertically and connected to each other by an erection jig 7 . The column component 3A and the column component 3B are temporarily connected by such an erection.

The welding device 1 includes two identical robots 9 , rails 11 for moving the robots 9 around the column component 3 , and a control unit 13 for controlling the motion and movement of the robots 9 .

The robot 9 is an articulated robot, for example, a general-purpose 6-axis vertical articulated robot. When distinguishing the two robots 9 from each other, they are referred to as "robot 9A" and "robot 9B", respectively. The robot 9A includes a groove sensor 15 (for example, a laser sensor) for sensing the groove shape (for example, cross-sectional shape of the groove) of the welded portion W as an end effector. The robot 9A operates under the control of the control unit 13, moves the groove sensor 15 along the welded portion W, and acquires the groove shape (for example, three-dimensional coordinate data of the groove). The acquired groove shape is temporarily stored in the control unit 13 . The robot 9B includes a welding tool 17 (for example, a welding torch for arc welding) for welding the welded portion W as an end effector. The robot 9B (welding robot) operates under the control of the control unit 13, moves the welding tool 17 along the welded portion W, and welds the welded portion W. As shown in FIG.

The rail 11 extends in an annular shape so as to surround the column component 3 at a position slightly lower than the welded portion W, and is fixed and supported on the outer peripheral surface of the column component 3A. The rail 11 has an annular shape centered on the material axis of the column component 3 in plan view. The rail 11 is provided with two carriages 19 that are slidable on the rail 11 and can travel separately. Each robot 9 is attached to a carriage 19 so that it can separately travel around the column part 3 along the rail 11 .

A mounting seat surface 21 of the carriage 19 is inclined with respect to the vertical plane. Also, the mounting seat surface 21 is parallel to the sliding direction of the carriage 19 . A first axis 23 (swivel axis) of the robot 9 attached to the mounting seat surface 21 is orthogonal to the mounting seat surface 21 and is inclined with respect to both the vertical direction and the horizontal plane. That is, the first axis 23 is neither a vertical axis nor a horizontal axis. According to this configuration, the movement range of the groove sensor 15 and the welding tool 17 moving along the horizontally extending welded portion W can be easily adjusted to a suitable movement range within the movement range of the robot 9. . That is, for example, it becomes easier to avoid a state in which the robot 9 operates in the vicinity of the movable limit of the arm.

The welding device 1 further includes a carriage 27 that can travel, for example, on a horizontal floor while the rails 11 are mounted thereon. The rail 11 on which the two robots 9</b>A and 9</b>B are installed is horizontally transported by the carriage 27 and installed around the column part 3 . Moreover, the truck 27 and the rail 11 can be separated, and when sensing by the robot 9A and welding by the robot 9B are performed, the rail 11 is insulated from the truck 27 and fixed to the column part 3A. As a result, it is possible to reduce the influence of floor vibration on the sensing accuracy of the robot 9A and the welding accuracy of the robot 9B.

[On-site welding method]
A method for welding the welded portion W using the welding apparatus 1 includes a sensing process and a welding process, which will be described below.

(Sensing process)
The controller 13 moves the robot 9A to an appropriate position on the rail 11. FIG. Then, the control unit 13 operates the robot 9A to move the groove sensor 15 along the welded portion W of the welding section to obtain the groove shape. The control unit 13 temporarily stores the groove shape acquired as described above. This sensing step is preferably executed with the carriage 19 stopped on the rail 11 and the position of the robot 9A stopped on the rail 11 . As a result, it is possible to reduce the influence of the motion accuracy of the carriage 19 on the sensing accuracy.

(Welding process)
Subsequently, the controller 13 moves the robot 9B to an appropriate position on the rail 11. FIG. Then, the controller 13 operates the robot 9B to move the welding tool 17 along the welded portion W in the welding section, thereby welding the welded portion W. As shown in FIG. At this time, the control unit 13 performs welding suitable for the groove shape based on the groove shape acquired and stored in the sensing step. For example, based on the stored groove shape, the control unit 13 uses a predetermined algorithm to determine the movement trajectory of the welding tool 17 in the cross section of the welded portion W, the movement speed of the welding tool 17, the attitude of the welding tool 17, and the like. Plan and move the welding tool 17 according to this plan. This welding process is preferably executed with the carriage 19 stopped on the rail 11 and the position of the robot 9B stopped on the rail 11 . As a result, the influence of the operating accuracy of the carriage 19 on the welding accuracy can be reduced.

In the above welding method, the target welding section is from the position covered by the erection jig 7 of one erection to the position covered by the erection jig 7 of the adjacent erection in the welded portion W. . In the present embodiment, one welding section is set in a quarter of the groove W of the welded portion W. As shown in FIG. Then, this welding method is repeated for each welding section, and the welding of the entire circumference of the groove of the welded portion W is completed. The sensing process for one weld zone and the welding process for another weld zone may be performed in parallel.

Further, here, since a vertical articulated robot is adopted as the robot 9B, the robot 9B can operate the welding tool 17 in a complicated manner, and welds the gap between the erection jig 7 and the welded portion W. The tip of tool 17 can be inserted. Therefore, according to this welding apparatus 1, the welding of the inner portion of the erection jig 7 is also performed in a state where the erection jig 7 exists, and the erection is performed after the welding of the entire circumference of the welded portion W is completed. Operation such as removing the jig 7 and the erection piece 5 is possible.

[Control section]
Next, the control unit 13 and the control executed by the control unit 13 in the welding operation of the welding section will be described in more detail.

(Configuration of control section)
FIG. 3 is a block diagram showing a functional configuration of a control unit; FIG. 4 is a diagram for explaining the processing content of the control unit. As shown in FIG. 3, the control unit 13 includes a storage unit 31, a sensing control unit 32, an area allocation unit 33, and a path allocation unit 34 as functional components (hereinafter referred to as "function modules"). , an operation pattern setting unit 35 , a speed pattern setting unit 36 , and a welding control unit 37 . These functional modules are simply the functions of the control unit 13 divided into a plurality of modules for convenience, and do not necessarily mean that the hardware constituting the control unit 13 is divided into such modules. Each functional module may be realized by executing a program, and is realized by a dedicated electric circuit (e.g. logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) that integrates this. may be

The sensing controller 32 controls the robot 9A. Specifically, the sensing control unit 32 executes a process of moving the robot 9A, a process of operating the robot 9A, and a process of sensing by the groove sensor 15. FIG. In the process of moving the robot 9A, the sensing control unit 32 moves the robot 9A to a position on the rail 11 facing the corner Wc. In the process of operating the robot 9A, the sensing control unit 32 operates the robot 9A so as to place the groove sensor 15 at one of the plurality of sensing positions. The multiple sensing positions include an initial sensing position and multiple groove sensing positions set by the area allocation unit 33 . The initial sensing position is, for example, a position facing the corner Wc.

In the sensing process, the sensing control unit 32 acquires the shape of a portion of the column parts 3A and 3B that includes the entire target welded section (for example, three-dimensional coordinate data of the surrounding environment of the welded section); and obtaining the groove shape of the. For example, the sensing control unit 32 provides, as the groove shape, data that associates the depth and height of the groove cross section that intersects (perpendicularly) with the extending direction of the groove and the relative position of the groove cross section in the welded section. (Groove data; for example, three-dimensional coordinate data of groove section) is acquired (data acquisition processing).

FIG. 4(a) is a plan view of the welded section. As shown in FIG. 4(a), the sensing control unit 32 sets the corner Wc to the origin O based on the shape of the portion of the column parts 3A, 3B that includes the entire target welded section. An orthogonal axis defined by an X-axis extending horizontally from the origin O along one side Ws, a Y-axis extending horizontally from the origin O along the other side Ws, and a Z-axis extending upward from the origin O A coordinate system S may be set, and each groove shape may be obtained based on the orthogonal coordinate system S. The sensing control unit 32 stores each acquired shape in the storage unit 31 .

The area allocation unit 33 allocates zone Z1 (first zone) to zone Zm (mth zone) (where m is a natural number of 2 or more) to the target welding section, and performs processing to allocate block B1 (first zone) to the welding section. block) to block Bn (n-th block) (where n is a natural number of 2 or more). In this embodiment, m is 5 and n is 7. However, m and n are not limited to this, and may be changed as appropriate.

The area allocation unit 33 allocates zones Z1 to Z5 corresponding to the types of parts in the column parts 3A and 3B to the welded sections, based on the shape of the portion of the column parts 3A and 3B that includes the entire target welded section. . In the present embodiment, zone Z1 is assigned to a site where an erection is provided at the upstream end of the welded section. The upstream end of zone Z1 is covered with a erection jig 7 . Zone Z2 is assigned to a flat site located upstream of the welded section with respect to corner Wc. Zone Z3 is assigned to a site containing corner Wc. Zone Z4 is assigned to a flat site located downstream of the welded section with respect to corner Wc. Zone Z5 is assigned to a site where an erection is provided at the downstream end of the welded section. The downstream end of zone Z5 is covered with a erection jig 7. As shown in FIG. The area allocation unit 33 stores the set allocation of each zone (hereinafter referred to as “zone allocation”) in the storage unit 31 .

In addition, the area allocation unit 33 allocates blocks B1 to B7 arranged in order along the extension direction of the groove of the welded portion W to the welding section. In this embodiment, block B1 is assigned to the section to which zone Z1 is assigned. Blocks B2 and B3 are assigned in this order to the section to which zone Z2 is assigned. Block B4 is assigned to the section to which zone Z3 is assigned. Blocks B5 and B6 are assigned in this order to the section to which zone Z5 is assigned. Block B7 is assigned to the section to which zone Z5 is assigned. The area allocation unit 33 saves the allocation of each block (hereinafter referred to as “block allocation”) set in the process of allocating the blocks B1 to Bn in the storage unit 31 .

In addition, the area allocation unit 33 sets the boundary between block Bi (i-th block) (where i is an arbitrary natural number from 1 to n−1) and block Bi+1 (i+1-th block) as a groove section to be sensed. do. In this embodiment, the area allocation unit 33 sets all of the boundaries between blocks as groove cross sections to be sensed, and sets positions facing each groove cross section as groove sensing positions. Here, the boundaries between zones coincide with the boundaries between blocks. However, the boundaries between zones need not coincide with the boundaries between blocks. Blocks B1 to Bn may include blocks allocated across boundaries between zones. For example, the blocks B1 to Bn may be allocated so that the intervals between the boundaries of the blocks are constant. The area allocation unit 33 transmits each set sensing position to the sensing control unit 32 .

A pass assigning unit 34 assigns a plurality of welding passes for welding a welded section to a block Bk (k-th block) (where k is a natural number from 1 to n). In the present embodiment, the pass allocation unit 34 allocates the same number of welding passes to blocks B1 to B7. The target weld section is welded with a common number of welding passes over the entire area. The term "welding pass" refers to one welding operation (designed section) performed along the extending direction of the groove. The welding pass extends along the extending direction of the groove. One weld bead is formed by one welding pass, and a plurality of weld beads are formed by a plurality of welding passes set by the pass allocation section 34, thereby welding the portion W to be welded.

FIG. 4(b) is a diagram showing an example of a cross-sectional view of the groove (a cross-sectional view of the groove along line IVB-IVB in FIG. 4(a)). The pass assigning unit 34 assigns each pass cross section P that intersects (perpendicularly) with the extending direction of the welding pass to each of the plurality of groove cross sections of the blocks B1 to B7. The plurality of groove cross-sections to which the allocation of the plurality of pass cross-sections P (hereinafter referred to as "pass allocation") is performed includes the groove cross-sections at the start ends and the groove cross-sections at the end of each of the blocks B1 to B7. The groove cross section at the end of blocks B1 to B6 and the groove cross section at the start end of blocks B2 to B7 are the groove cross sections to be sensed set by the area allocation unit 33 (that is, each boundary between blocks). The path allocation unit 34 acquires the groove data of the target groove cross section from the storage unit 31 . As the groove data of the groove cross section at the start end of the block B1 and the groove cross section at the end of the block B7, groove data set using groove data of adjacent groove cross sections may be substituted.

Based on the groove data stored in the storage unit 31, the path allocation unit 34 executes processing for setting a plurality of path cross sections P to be allocated to each groove cross section (third setting processing). The processing for setting a plurality of pass sections P includes the first processing for calculating the number of layers of the path section P (the number of lamination in the depth direction of the groove), the number of steps in the path section P (the number of lamination in the height direction of the groove) number), and a third process of allocating a plurality of path sections to the groove section so as to satisfy the calculation result of the first process and the calculation result of the second process.

In the first process, the number of layers of the path cross section P is adjusted so that the thickness of each layer (eg, the thickness D1 of the lower end of each layer) is within a predetermined range (eg, less than 9 mm), and the depth of the groove cross section (eg, , the depth D2) of the lower end of each layer. The range of the thickness D1 may be set to, for example, 4.5 mm or more and less than 9 mm. The number of stages of the path cross section P is calculated for each layer. In the second process, the number of steps of each layer of the path section P (in the example of FIG. 4B, the second layer from the back of the groove) is determined by the width of each step (for example, the vertical width of the deepest part of each step D3 ) is within a predetermined range (for example, less than 9 mm), it is calculated according to the height of each layer of the groove cross section (for example, the height D4 of the deepest part of each layer). The range of the width D3 may be set to, for example, 4.5 mm or more and less than 9 mm. In the third process, the groove cross section is divided (for example, evenly divided) according to the calculated number of layers and steps, and pass division is performed. The pass allocation unit 34 may set each division point obtained by the division as the target position K of the welding tool 17 . In addition, the path allocation unit 34 further sets a position behind the target position K by the projection length (eg, 5 mm) of the filler material (eg, welding wire) from the welding tool 17 as a correction target position. good too.

The pass allocation unit 34 stores in the storage unit 31 a plurality of pass allocations and a plurality of target positions K set for each groove section. If the number of pass sections P (here, the number of layers and the number of stages of each layer) is not common for all groove sections, the pass allocation unit 34 sets the number of pass sections P for all groove sections so that they are common. You may perform the adjustment process which adjusts to . The pass assigning unit 34 may share the number of pass cross sections P for all groove cross sections according to the groove cross section with the largest number of pass cross sections P, or may match the number of pass cross sections P with the groove cross section with the smallest number of pass cross sections P. Therefore, the number of pass cross sections P of all groove cross sections may be made common. Further, the pass allocation unit 34 may perform a resetting process of resetting the pass allocation for groove cross sections whose number of pass cross sections P is to be changed in the adjustment process.

The operation pattern setting unit 35 performs a process (type acquisition process) for acquiring information about the type of the part in the columnar parts 3A and 3B in the zone Zj (j-th zone) (where j is a natural number from 1 to m). = 1 to m (j = 1 to 5 in this embodiment). Specifically, the operation pattern setting unit 35 acquires from the storage unit 31 the zone allocation of the target weld section and the types of parts to which the zones Z1 to Z5 are assigned in the column parts 3A and 3B.

In this embodiment, the zone Z1 is assigned to a portion of the column parts 3A, 3B where an erection is provided at the upstream end of the welded section. The zone Z2 is assigned to a portion of the column parts 3A, 3B that is flat and located on the upstream side of the welded section with respect to the corner portion Wc. Zone Z3 is assigned to a portion of column parts 3A and 3B that includes corner Wc. The zone Z4 is assigned to a portion of the column parts 3A, 3B that is flat and located downstream of the welded section with respect to the corner portion Wc. Zone Z5 is assigned to a portion of column parts 3A and 3B where an erection is provided at the downstream end of the welded section.

In addition, the operation pattern setting unit 35 sets the j-th operation pattern for adjusting the orientation of the welding tool 17 when welding the zone Zj according to the type of the part in the column components 3A and 3B of the zone Zj (the j-th operation pattern). 2 setting process) is executed for j=1 to m (j=1 to 5 in this embodiment). For example, the operation pattern setting unit 35 sets the pattern of how to move the tip of the welding tool 17 when welding the zones Z1 to Z5. Each operation pattern may be selected from a plurality of preset operation patterns.

FIG. 5(a) is a schematic plan view for explaining an operation pattern, and FIG. 5(b) is an enlarged view showing a part of FIG. 5(a). In this embodiment, when welding the zone Z1, when viewed from above, the tip of the welding tool 17 is tilted backward along the extending direction of the groove from the extending direction of the groove. The first operation pattern may be set so as to gradually change in a direction perpendicular to the . When welding the zone Z2, the second operation pattern may be set so that the tip of the welding tool 17 is maintained in a direction perpendicular to the extending direction of the groove when viewed from above.

Zone Z3 is assigned to a site including corner Wc, as described above. As shown in FIG. 5(b), in zone Z3, welded portion W includes extension portions W1, W2 and corner portion W3. The extension W1 (first extension) is a portion extending from the corner W3 along the first direction (X-axis direction shown in FIG. 4A). The extension W2 (second extension) is a portion extending from the corner W3 along the second direction (Y-axis direction shown in FIG. 4A). In the following description, the corner portion W3 particularly refers to a portion of the welded portion W along the straight line Lc that bisects the angle formed by the extending direction of the extending portion W1 and the extending direction of the extending portion W2.

When welding the zone Z3, the welding tool 17 is welded in the order of the extending portion W1, the corner portion W3, and the extending portion W2 along the extending direction of the welded portion W (that is, the extending direction of the groove). A third operation pattern may be set such that the orientation of the welding tool 17 is sequentially changed between the first state, the second state, and the third state while moving the .

The first state is a direction in which the tip of the welding tool 17 intersects the extending direction of the extending portion W1, as indicated by a two-dot chain line T1 in FIG. 5(b). In the first state, the posture of the welding tool 17 is suitable for welding the extension W1. When viewed from above, the tip of the welding tool 17 in the first state is maintained in a direction perpendicular to the extension direction of the groove of the extension portion W1.

In the second state, the tip of the welding tool 17 faces the groove of the corner W3 as indicated by the solid line T2 in FIG. 5(b). In the second state, the posture of the welding tool 17 is such that the tip of the welding tool 17 follows the straight line Lc. When viewed from above, the tip of the welding tool 17 in the second state is maintained in an orientation inclined by 45° from the first state (an orientation inclined by 45° from the third state).

The third state is a direction in which the tip of the welding tool 17 intersects the extending direction of the extending portion W2, as indicated by a two-dot chain line T3 in FIG. 5(b). In the third state, the posture of the welding tool 17 is suitable for welding the extension W2. When viewed from above, the tip of the welding tool 17 in the third state is maintained in a direction that is slightly inclined forward with respect to the direction orthogonal to the extending direction of the groove of the extending portion W2.

In the third operation pattern, while the welding tool 17 moving along the extension W1 reaches the corner W3 from a position separated by a distance L1 (first distance) from the corner W3, the welding tool 17 is gradually changed from the first state to the second state. The distance L1 is, for example, approximately 5 mm. Further, after the orientation of the welding tool 17 is changed from the first state to the second state, the movement of the welding tool 17 is stopped for a predetermined time (for example, 0.3 seconds). After a predetermined time has passed, the welding tool 17 moving along the extended portion W2 moves away from the corner W3 to a position a distance L2 (second distance) away from the corner W3. The second state is gradually changed to the third state. The distance L2 is, for example, approximately 10 mm.

In the zone Z3, the welding tool 17 is fixed in the first state on the upstream side of the position separated from the corner W3 by the distance L1. Further, in the zone Z3, the welding tool 17 is fixed in the third state downstream of the position separated from the corner W3 by the distance L2.

Furthermore, the third operation pattern may include a backward pattern (stop process) and a forward pattern (forward process). In the retreating pattern, the welding tool 17 moving along the extended portion W1 reaches the corner W3 from a position separated by a distance L3 (third distance) from the corner W3. It is set to retract the welding tool 17 in a direction away from the tip. Distance L3 is, for example, the same as distance L1. However, the distance L3 may differ from the distance L1. In the forward pattern, while the welding tool 17 moving along the extended portion W2 moves away from the corner W3 to a position a distance L4 (fourth distance) away from the corner W3, the welding tool moves backward in the backward pattern. 17 is set to move forward. Distance L4 is, for example, the same as distance L2. However, the distance L4 may differ from the distance L2. In the retreat pattern, the distance L5 by which the welding tool 17 moves away from the groove of the welded portion W is, for example, about 3 mm.

When welding the zone Z4, the fourth welding tool 17 is maintained in a direction slightly inclined forward with respect to the direction orthogonal to the extending direction of the groove when viewed from above. An operation pattern may be set. Alternatively, the fourth operation pattern may be set so that the tip of the welding tool 17 is maintained in a direction perpendicular to the extending direction of the groove when viewed from above. When welding the zone Z5, the orientation of the tip of the welding tool 17, viewed from above, gradually changes from the orientation set in the zone Z4 to the orientation inclined forward along the extending direction of the groove. The fifth operation pattern may be set so as to do so.

In addition, the operation pattern setting unit 35 performs weaving welding of at least a part of the zones Z1 to Z5 (that is, the welding tool 17 each operation pattern may be set so as to swing up and down). In addition, in the upper welding pass (welding operation of each pass section PU in FIG. 4B), the operation pattern setting unit 35 sets the welding tool 17 so that it faces obliquely upward in at least a part of the zones Z1 to Z5. , each operation pattern may be set.

The speed pattern setting unit 36 stores information on the area of the pass cross section P that intersects the extending direction of the welding pass when welding the block Bk (k-th block) (where k is a natural number from 1 to n) in the storage unit 31. (area acquisition processing) is executed for each of k=1 to n (k=1 to 7 in this embodiment). For example, the speed pattern setting unit 36 acquires from the storage unit 31 the block division of the target welded section and the pass division of each groove cross section at the boundary between each block. The speed pattern setting unit 36 may acquire both the pass division of the groove cross section at the start end of the block B1 and the pass division of the groove cross section at the end of the block B7.

Further, the speed pattern setting unit 36 performs processing (first setting processing) for setting the k-th speed pattern, which is the pattern of the moving speed of the welding tool 17 when welding the block Bk, from k=1 to n (main In the embodiment, it is performed for k=1 to 7). Specifically, the speed pattern setting unit 36 sets first to seventh speed patterns, which are patterns of how to adjust the speed of moving the welding tool 17 of the robot 9B when welding the blocks B1 to B7. do. The speed pattern setting unit 36 may set the first to seventh speed patterns for each welding pass, or may set the first to seventh speed patterns common to all welding passes. good too.

The speed pattern setting unit 36 sets the first speed pattern to the seventh speed pattern so that the average value of the moving speed of the welding tool 17 in the block Bk and the average value of the area of the pass cross section P in the block Bk have a negative correlation. Set the speed pattern. For example, the first to seventh speed patterns are set so that the product of the average value of the moving speed of the welding tool 17 and the average value of the area of the pass cross section P is constant among all of the blocks B1 to B7. set. In the present embodiment, the speed pattern setting unit 36 sets the first speed pattern to the seventh speed pattern for all of the blocks B1 to B7 according to the area of the path cross section P at the boundary of each block.

As an example, the area of the path cross section P at the boundary between the blocks B1 and B2 set by the path allocation unit 34 (hereinafter referred to as "first area") is the area of the path cross section P at the boundary between the blocks B2 and B3 (hereinafter referred to as (referred to as a "second area") and smaller than the area of the path cross section P at the boundary between the blocks B3 and B4 (hereinafter referred to as a "third area"). At this time, the average value of the area of the path cross section P in the block B2 (here, the average value of the first area and the second area) is the average value of the area of the path cross section P in the block B3 (here, the second area and the average value of the third area). Therefore, the speed pattern setting unit 36 sets the second speed pattern (block B2 to A moving speed pattern of the welding tool 17 during welding) and a third speed pattern (a moving speed pattern of the welding tool 17 during welding of the block B2) are set.

The speed pattern setting unit 36 may set, as the second speed pattern, a constant speed that is the average value of the speed suitable for welding the first area and the speed suitable for welding the second area. Alternatively, the speed pattern setting unit 36 sets the second speed pattern such that the speed suitable for welding the first area gradually changes to the speed suitable for welding the second area (increase here). You may At this time, the second speed pattern may be set to change continuously or may be set to change stepwise. The first, third to seventh speed patterns may be similarly set.

The speed pattern setting unit 36 sets the speed suitable for welding of the area of the pass cross section P used when setting each speed pattern, the supply speed of the filler material (the amount of filler material supplied per unit time) to the area It can be obtained by dividing by . Alternatively, the speed pattern setting unit 36 may obtain the speed suitable for welding of the target area by multiplying the value obtained by dividing the supply speed of the filler material by the area by a correction value. The correction value includes, for example, a correction value considering the influence of spatter during welding, a correction value corresponding to the difference in unit weight of the filler material, and the like. A correction value considering the influence of spatter during welding is, for example, about 0.95. The correction value may be determined in advance by experiments.

The welding control section 37 controls the robot 9B. Specifically, the welding control unit 37 executes a process of moving the robot 9B, a process of operating the robot 9B, and a process of adjusting the state of welding by the welding tool 17. FIG. In the process of moving the robot 9B, the welding control unit 37 moves the robot 9B to a position on the rail 11 facing the corner Wc. In the process of operating the robot 9B, the welding control unit 37 performs welding in the j-th zone while adjusting the direction of the welding tool 17 according to the j-th operation pattern set by the operation pattern setting unit 35, and the speed pattern setting unit 36 Processing for controlling the robot 9B (robot control processing) so that the welding tool 17 performs welding of the kth block while moving according to the set kth speed pattern is performed for k=1 to n and j=1 to m, respectively. Execute.

In addition, in the process of adjusting the welding state, the welding control unit 37 adjusts the welding current value for each welding pass, the supply speed of the filler material, and the like. In the welding control unit 37, the position of each pass cross section P (for example, how many layers it is from the back of the groove) and welding conditions (for example, welding current value and filler material supply speed) are associated in advance. The welding state may be adjusted with reference to the table.

In addition, as a process for adjusting the welding state, the welding control unit 37 continuously controls the welding tool 17 in the zone Z3 while the welding tool 17 moves in the order of the extension portion W1, the corner portion W3, and the extension portion W2. The robot 9B may be controlled so as to generate an arc discharge. In this embodiment, the welding control unit 37 controls the robot 9B so as to continuously generate an arc discharge in the welding tool 17 while the welding tool 17 moves across the blocks B1 to B7 (zones Z1 to Z3). do.

The hardware of the control unit 13 is configured by, for example, one or more control computers. In this embodiment, the welding device 1 has one controller 100 . When the control unit 13 is composed of a plurality of computers, each of the above functional modules may be realized by one computer, or may be realized by a combination of two or more computers.

(On-site welding processing)
Next, an outline of on-site welding processing by the control unit 13 will be described. FIG. 6 is a flow chart showing the procedure of on-site welding processing. As shown in FIG. 6, the control unit 13 first executes step S01. In step S01, the sensing control unit 32 controls the robot 9A to perform sensing. Specifically, the sensing control unit 32 executes a process of moving the robot 9A, a process of operating the robot 9A, and a process of sensing by the groove sensor 15. FIG.

The sensing control unit 32 first moves the robot 9A to a position on the rail 11 facing the corner Wc. Next, as shown in FIG. 7A, the sensing control unit 32 operates the robot 9A so as to place the groove sensor 15 at the initial sensing position. In this state, the sensing control unit 32 controls the robot 9A so that the groove sensor 15 performs sensing, and acquires the shape of the portion of the column parts 3A, 3B that includes the entire target welded section.

Next, the control unit 13 executes step S02. In step S02, the area allocation unit 33 executes a process of allocating zones Z1 to Z5 to the target welding section and a process of allocating blocks B1 to B7 to the welding section based on the sensing result in step S01 ( See FIG. 4(a)). Further, the area allocation unit 33 sets all the boundaries between blocks as groove cross sections to be sensed, and sets positions facing each groove cross section as groove sensing positions.

Next, the control unit 13 executes step S03. In step S<b>03 , the sensing control unit 32 executes a process of operating the robot 9</b>A and a process of sensing by the groove sensor 15 . As shown in FIG. 7B, the sensing control unit 32 operates the robot 9A so as to place the groove sensor 15 at the groove sensing position set by the area allocation unit 33. As shown in FIG. In this state, the sensing control unit 32 controls the robot 9A so that the groove sensor 15 performs sensing, and acquires groove data. The sensing control unit 32 executes this processing at all groove sensing positions set by the area allocation unit 33, and acquires all groove data set as groove cross sections to be sensed.

Next, the control unit 13 sequentially executes steps S04 and S05. In step S04, the pass assigning section 34 assigns a plurality of welding passes for welding the welding section to the blocks B1 to B7. In step S05, the control unit 13 controls the robot 9B to weld the welding section. Specifically, the control unit 13 performs processing for setting the pattern of how to move the tip of the welding tool 17 when the operation pattern setting unit 35 welds the zones Z1 to Z5, and the speed pattern setting unit 36 blocks. A process of setting each pattern of how to adjust the speed of moving the welding tool 17 of the robot 9B when welding B1 to B7, and the welding control unit 37 controls the robot 9B so as to weld the target welding section. , and , respectively. Specific processing contents of steps S04 and S05 will be described in detail below.

(Path allocation processing)
An example of specific processing contents of step S04 will be described. FIG. 8 is a flow chart showing the procedure of bus allocation processing. FIG. 9 is a sectional view of the bevel for explaining the bus allocation process. As shown in FIG. 8, the control unit 13 first executes step S41. In step S41, the pass assigning unit 34 acquires each groove data from the storage unit 31, and specifies a groove cross-section for which pass splitting is not set as a groove cross-section to be subjected to pass splitting this time. The pass assigning unit 34 may perform pass assignment in order from the groove cross section upstream of the welded section to the groove cross section downstream, or a special groove cross section (for example, a groove cross section with the largest area or A groove section having the smallest area, etc.) may be divided first.

Next, the control unit 13 executes step S42. In step S42, the pass assigning unit 34 executes a first process of calculating the number of layers of the pass cross section P for the identified groove cross section. As shown in FIG. 9A, the pass assigning unit 34 calculates the number of layers of the pass section P according to the depth D2 of the groove section so that the thickness D1 of each layer is within a predetermined range.

Next, the control unit 13 executes step S43. In step S43, the pass assigning unit 34 executes a second process of calculating the number of stages of the pass cross section P for the identified groove cross section. As shown in FIG. 9B, the path allocation unit 34 calculates the number of stages of the path cross section P for each layer. The path allocation unit 34 divides each layer of the path section P (in the example of FIG. 9B, the width of the groove in the example of FIG. 2nd layer from the back) is calculated.

Next, the control unit 13 executes step S44. In step S44, the pass allocation unit 34 executes a third process of allocating a plurality of pass cross sections to the specified groove cross section so as to satisfy the calculation result of the first process and the calculation result of the second process. The pass allocation unit 34 divides (for example, divides evenly) the groove cross-section according to the calculated number of layers and the number of stages to perform pass allocation (see FIG. 4B). Moreover, the path allocation unit 34 may set each division point obtained by the division as the target position K of the welding tool 17 . The pass allocation unit 34 stores the set pass allocation and each target position K in the storage unit 31 .

Next, the control unit 13 executes step S45. In step S45, the pass assigning unit 34 checks whether or not pass assignments have been set for all groove cross sections to be subjected to pass assignment. In the present embodiment, the groove cross sections at the start ends and the groove cross sections at the end ends of the blocks B1 to B7 are the targets for pass splitting. If there is a groove cross-section for which pass splitting is not set among all the groove cross-sections to be subjected to pass splitting, the control unit 13 returns the process to step S41. After that, the control unit 13 repeatedly executes steps S41 to S44 until pass splitting is set for all the groove cross sections to be pass splitted.

After setting the pass splitting for all groove cross sections to be subjected to pass splitting, the control unit 13 executes step S46. In step S46, the pass assigning unit 34 checks whether or not the number of welding passes (that is, the number of pass cross sections P) of all groove cross sections for which pass assignment has been performed is common. For example, the pass assigning unit 34 determines whether or not the number of layers of the path cross sections P of all target groove cross sections is common, and whether the number of layers of the pass cross sections P of all target groove cross sections is common. Check whether or not

If it is determined in step S46 that the number of welding passes for all the groove cross sections for which pass division has been performed is not common, the control section 13 executes step S47. In step S47, the pass allocation unit 34 adjusts each pass allocation so that the number of welding passes is common to all the groove cross sections on which the pass allocation is performed.

In this embodiment, each pass division is adjusted so that the number of layers of the path cross sections P of all the groove cross sections is common and the number of layers of the pass cross sections P of all the groove cross sections is common. For example, the pass assigning unit 34 assigns the number of layers of the pass cross sections P of all the groove cross sections according to the number of layers of the pass cross section P of the groove cross section P in accordance with the groove cross section having the largest number of layers of the pass cross section P. Let Alternatively, the pass assigning unit 34 shares the number of layers of the pass cross sections P of all the groove cross sections according to the number of layers of the pass cross section P of the groove cross section according to the groove cross section having the smallest number of layers of the pass cross section P. Let Similarly, the number of steps in each layer of the path section P is made common to all groove sections according to the groove section with the largest number of steps (or the groove section with the smallest number of steps).

The pass allocation unit 34 resets the pass allocation and each target position K for the groove cross section whose number of pass cross sections P is to be changed by the above adjustment. For example, the pass allocating unit 34 divides (e.g., divides evenly) the groove cross section according to the number of layers and the number of stages of the common pass cross section P, and divides the groove into passes. The pass allocation unit 34 updates the pass allocation and each target position K in the storage unit 31 .

Thus, the control unit 13 completes control for path allocation processing. If it is determined in step S46 that the number of welding passes is the same for all groove cross sections for which pass assignment has been performed, the control unit 13 omits step S46 and completes the control for pass assignment processing. .

(robot welding process)
Next, specific processing contents of step S05 will be described. FIG. 10 is a flowchart showing the procedure of robot welding processing. In addition, FIG. 10 shows the procedure of the robot welding process by one welding pass. One welding pass passes through the pass cross section P at the same position (here, the pass cross section P at the same stage in the same layer) of all the groove cross sections for which the pass division was performed in step S06, and the target welding section extends over the entire area of In the present embodiment, robot welding processing by all welding passes (welding passes for P number of pass cross sections) is performed with the robot 9B stopped at a position on the rail 11 facing the corner Wc.

As shown in FIG. 10, the control unit 13 first executes step S51. In step S51, the operation pattern setting unit 35 and the speed pattern setting unit 36 confirm the target area (here, block Bk of zone Zj). Specifically, the operation pattern setting unit 35 confirms which of the zones Z1 to Z5 the zone Zj of the target area is based on the zone division and block division of the target welding section. Also, the speed pattern setting unit 36 confirms which of the blocks B1 to B7 the block Bk of the target area is.

Next, the control unit 13 executes step S52. In step S52, the motion pattern setting unit 35 acquires from the storage unit 31 the type of the part to which the zone Zj is assigned in the column parts 3A and 3B. The types of parts to which zone Zj is assigned in column parts 3A and 3B are a part provided with an erection at the upstream end of the welded section (when j=1) and a flat part, A portion located on the upstream side of the welded section with respect to the portion Wc (when j=2), a portion including the corner portion Wc (when j=3), and a flat portion where the corner portion Wc 4 (in the case of j = 4) and a portion (in the case of j = 5) provided with an erection at the downstream end of the welded section (Fig. 4 ( a) see).

Next, the control unit 13 executes step S53. In step S53, the operation pattern setting unit 35 sets the j-th operation pattern for adjusting the orientation of the welding tool 17 when welding the zone Zj according to the type of parts in the column parts 3A and 3B of the zone Zj. The operation pattern setting unit 35 sets any one of the first to fifth operation patterns. In the first operation pattern, the orientation of the tip of the welding tool 17 seen from above gradually changes from a rearwardly inclined orientation along the extending direction of the groove to a direction orthogonal to the extending direction of the groove. (See FIG. 5(a)). In the second operation pattern, the tip of the welding tool 17 is maintained in a direction perpendicular to the extending direction of the groove when viewed from above.

In the third operation pattern, as shown in FIG. 5(b), the orientation of the welding tool 17 is set to the first direction while the welding tool 17 moves in the order of the extension portion W1, the corner portion W3, and the extension portion W2. state (the state indicated by the two-dot chain line T1 in FIG. 5(b)), the second state (the state indicated by the solid line T2 in FIG. 5(b)) and the third state (the two-dot chain line T3 in FIG. 5(b) The state indicated by ) gradually changes between Specifically, the orientation of the welding tool 17 changes from the first state until the welding tool 17 moving along the extension W1 reaches the corner W3 from a position separated from the corner W3 by the distance L1. Gradually change to the second state. Further, after the orientation of the welding tool 17 is changed from the first state to the second state, the movement of the welding tool 17 is stopped for a predetermined time in that state. After a predetermined time has passed, the welding tool 17 moving along the extended portion W2 moves away from the corner W3 to a position a distance L2 away from the corner W3, and the orientation of the welding tool 17 changes from the second state to the second state. It gradually changes to three states.

Furthermore, in the third operation pattern, the welding tool 17 moving along the extended portion W1 reaches the corner portion W3 from a position separated from the corner portion W3 by the distance L3. The welding tool 17 is retracted in a direction away from . Also, while the welding tool 17 moving along the extended portion W2 moves away from the corner W3 to a position at a distance L4 from the corner W3, the welding tool 17 is advanced by the retreated amount in the retreat pattern.

In the fourth operation pattern, the tip of the welding tool 17 is maintained in a direction slightly inclined forward with respect to a direction perpendicular to the extending direction of the groove when viewed from above (see FIG. 5(a)). . Alternatively, the tip of the welding tool 17 is maintained in a direction perpendicular to the extending direction of the groove when viewed from above. In the fifth operation pattern, the orientation of the tip of the welding tool 17 viewed from above gradually changes from the orientation set in the zone Z4 to the orientation inclined forward along the extending direction of the groove (Fig. 5 (a)).

Next, the control unit 13 executes step S54. In step S<b>54 , the speed pattern setting unit 36 acquires from the storage unit 31 information about the area of the path cross section P of the block Bk. The speed pattern setting unit 36 acquires at least the area of the path cross section P of each groove cross section at the start and end of the block Bk. The speed pattern setting unit 36 may acquire path divisions of groove cross sections at the start end and the end end of the block Bk. Alternatively, the speed pattern setting unit 36 sets the pass division of each groove cross section at the boundary between blocks, the pass division of the groove cross section at the start end of block B1, and the pass division of the groove cross section at the end of block B7. may be obtained at the same time.

Next, the control unit 13 executes step S55. In step S55, the speed pattern setting unit 36 sets the k-th speed pattern, which is the moving speed pattern of the welding tool 17 when welding the block Bk. The speed pattern setting unit 36 sets the k-th speed pattern such that the average value of the moving speed of the welding tool 17 in the block Bk and the average value of the area of the pass cross section P in the block Bk have a negative correlation. . As the k-th speed pattern, a constant speed that is the average value of the speed suitable for welding the area of the pass cross section P at the beginning of the block Bk and the speed suitable for welding the area of the pass cross section P at the end of the block Bk is set. may be Alternatively, the k-th speed pattern is set to gradually change from a speed suitable for welding the area of the pass cross section P at the beginning of the block Bk to a speed suitable for welding the area of the pass cross section P at the end of the block Bk. may

Next, the control unit 13 executes step S56. In step S56, the operation pattern setting unit 35 and the speed pattern setting unit 36 determine whether each setting for all areas (here, zones Z1 to Z5 and blocks B1 to B7) within the target welding section has been completed. confirm. In other words, it is determined whether or not the operation pattern setting unit 35 has set the jth operation pattern for j=1 to 5, and the speed pattern setting unit 36 has set the kth speed pattern for k=1 to 7. confirm.

If there is an area for which setting has not been completed (here, if the speed pattern setting unit 36 determines that the k-th speed pattern has not been set for at least one of k=1 to 7), the control unit 13 returns the process to step S51. After that, the control unit 13 repeatedly executes steps S51 to S55 until each setting for all areas in the target welding section is completed. That is, the operation pattern setting unit 35 sets the j-th operation pattern for j=1-5, and the speed pattern setting unit 36 sets the k-th speed pattern for k=1-7.

After completing each setting for all areas in the target welding section, the control unit 13 executes step S57. In step S57, the welding control unit 37 controls the robot 9B to weld the target welding section. Specifically, the welding control unit 37 executes a process of operating the robot 9B and a process of adjusting the state of welding by the welding tool 17. FIG. In the process of operating the robot 9B, the welding control unit 37 performs welding according to the k-th speed pattern set by the speed pattern setting unit 36 while adjusting the orientation of the welding tool 17 according to the j-th operation pattern set by the operation pattern setting unit 35. A process for controlling the robot 9B so that the tool 17 moves is executed for k=1 to 7 and j=1 to 5, respectively. In addition, in the process of adjusting the welding state, the welding control unit 37 adjusts the welding current value, the supply speed of the filler material, and the like. Also, the welding control unit 37 controls the robot 9B so as to continuously generate an arc discharge in the welding tool 17 while the welding tool 17 moves across the blocks B1 to B7 (zones Z1 to Z3).

As described above, the control unit 13 completes the control for the robot welding process by one welding pass. Welding of the target welding section is completed by repeating the control for the robot welding process as many times as the number of path cross sections P. The control unit 13 repeatedly executes the above control for the robot welding process until all welding passes are completed. The completion of all the welding passes completes the welding of the target welding section (the section set at the 1/4 groove of the portion to be welded W). The control unit 13 repeats this on-site welding process for each welding section, and completes the welding of the entire circumference of the groove of the welded portion W. As shown in FIG.

Note that the control unit 13 may be configured to execute the next step after executing the processing for all of k=1 to 7 and j=1 to 5 in each of steps S52, S53, and S54. good. In this case, the control unit 13 omits steps S51 and S56 and executes step S57.

In addition, the control unit 13 controls the starting end (here, the starting end of zone Z1) and the terminal end (here, the starting end of zone Z1) of the target welding section according to the progress of welding of the welding section adjacent to the target welding section among the welded parts W. Then, at the end of zone Z5), it is determined whether the weld bead build-up is cascaded (stepped) or reverse cascaded (vertically inverted stepped), and based on the determination result , further processing may be performed to adjust the start and end points of each weld pass.

The effects of the welding device 1 described above will be described. In the welding device 1 according to the present embodiment, the control unit 13 that controls the robot 9B performs an area acquisition process for acquiring information about the area of the pass cross section P of the welding pass, and the welding tool 17 for welding the block Bk. a first setting process for setting a k-th speed pattern, which is a moving speed pattern; a robot control process for controlling the robot 9B so as to weld the block Bk while the welding tool 17 moves according to the k-th speed pattern; for k=1 to 7, respectively.

Here, the first speed pattern to the seventh speed pattern each have a negative correlation between the average value of the moving speed of the welding tool 17 in the block Bk and the average value of the area of the pass cross section P in the block Bk. set. As a result, the moving speed of the welding tool 17 of the robot 9B is adjusted so that the weld bead formed over the blocks B1 to B7 has a thickness corresponding to the area of the path cross section P between the blocks. . Therefore, the thickness of the weld bead can be adjusted in one welding pass without adjusting other welding conditions (for example, even when the supply speed of the filler material is constant). Therefore, even if the shape of the groove of the welded portion W of the column parts 3A, 3B is not constant for each location (that is, even if there is a taper gap in the welded section), the shortage of the weld bead This reduces the risk of occurrence of spots, excess spots, and the like. As described above, it is possible to suppress deterioration in welding quality when automating on-site welding.

By the way, for example, when a taper gap exists in a weld section, if only a weld bead with a constant thickness can be formed, the number of welding passes may be increased or decreased in the middle of the weld section according to the taper gap. When increasing or decreasing the number of welding passes, the arc discharge of the welding tool 17 is interrupted, which may lead to deterioration of welding quality. On the other hand, according to the welding apparatus 1, a weld bead having a thickness corresponding to the size of the area of the path cross section P between blocks is formed. It is possible to perform welding with a common number of welding passes over the entire welding section. Since the controller 13 in the welding device 1 allocates the same number of welding passes to the blocks B1 to B7, it is possible to suppress deterioration in welding quality due to interruption of the arc discharge of the welding tool 17.

In addition, in the welding device 1, the welding section includes zones Z1 to Z5 in which the types of grooved portions of the column parts 3A and 3B are different from each other. The control unit 13 performs a type acquisition process for acquiring information about the type of the part of zone Zj, and a second setting process for setting the j-th operation pattern for adjusting the orientation of the welding tool when welding zone Zj. Run for j=1-5. In the robot control process, the control unit 13 controls the robot 9B so as to perform welding in the zone Zj while adjusting the orientation of the welding tool 17 according to the jth motion pattern. As a result, even if there are different types of grooved portions in the column parts 3A and 3B in the welded section, it is possible to automate field welding.

In the welding device 1, the column parts 3A, 3B include two side surface portions Ws that intersect with each other and a corner portion Wc between the two side surface portions Ws. The groove extends from one side surface portion Ws to a side surface portion Ws different from the one side surface portion Ws, and the two side surface portions Ws are provided with erections (the erection piece 5 and An erection jig 7) is provided respectively. In the groove, a welding section is set from a position covered by one erection to a position covered by an adjacent erection. In other words, the welded section in this embodiment includes the corner Wc and the position covered by the erection. Thus, according to the welding apparatus 1, all welding sections including the welding section where the corner Wc, the position covered with the erection, etc. are mixed can be welded on site by automation.

In addition, the welding device 1 provides a groove including the position of the groove cross section that intersects the extension direction of the groove (the direction in which the blocks B1 to B7 are arranged), the depth of the groove cross section, and the height of the groove cross section. It further comprises a bevel sensor 15 that acquires tip data. The control unit 13 performs a data acquisition process for acquiring groove data of the groove cross section at the boundary between blocks using the groove sensor 15, and a plurality of pass cross sections to be allocated to the groove cross section based on the groove data. A third setting process for setting P is further executed. The third setting process includes a first process of calculating the number of layers of the pass cross section P according to the depth D2 of the groove cross section so that the thickness D1 of each layer of the pass cross section P is within a predetermined range; A second process of calculating the number of steps of each layer of the path cross section P according to the height D4 of each layer of the groove cross section so that the width D3 of each step is within a predetermined range; and a third process of allocating a plurality of pass cross sections P to the groove cross section so as to satisfy the calculation results of the second process. In the third process, the groove cross section is divided in the depth direction by the calculation result of the first process, and each layer of the groove cross section is divided in the height direction by the calculation result of the second process. A point is set at the aim position K of the welding tool 17 .

With the above configuration, it is possible to automatically allocate a plurality of pass cross sections P to the groove cross section, and to set the target position K of the welding tool 17 by utilizing the allocation of the pass cross sections P. When welding is performed, from the viewpoint of ease of work, there are cases in which welding is performed sequentially from the deepest layer in a plurality of pass cross sections P, and welding is performed sequentially from the lower stage to the upper stage in each layer. In such a case, according to the target position K, the filler material is supplied toward the innermost position where no weld bead is formed, so a gap is less likely to be formed between the weld beads. Therefore, it is possible to further suppress the deterioration of welding quality when automating on-site welding.

Further, in the welding apparatus 1 according to the present embodiment, the control unit 13 that controls the robot 9B controls the robot 9B so as to move the welding tool 17 along the extending direction of the welded portion W; While the welding tool 17 is moving, a process of controlling the robot 9B to continuously generate an arc discharge in the welding tool 17 and a process of controlling the robot 9B to change the orientation of the welding tool 17 are executed. do. Further, the orientation of the welding tool 17 is gradually changed while the welding tool 17 moving along the extension W1 reaches the corner W3 from a position separated from the corner W3 by the distance L1. The welding tool 17 moving along the extension W2 is gradually changed while moving away from the corner W3 to a position separated by a distance L2 from the corner W3. Therefore, since the posture of the welding tool 17 is slowly changed while the welding tool 17 is being moved, excessive adhesion of the weld metal to the corner portion W3 is suppressed. As a result, dripping of the deposited metal is suppressed, and the shape of the weld bead becomes smooth. Therefore, deterioration of welding quality at the corner W3 can be suppressed.

By the way, the groove cross-section at the corner W3 is larger than the other groove cross-sections. In this embodiment, the cross-sectional size of the groove of the corner W3 is approximately 1.4 times the size of the cross-sectional groove of the extensions W1 and W2. Therefore, if the attitude of the welding tool 17 is changed without interrupting welding at the corner W3, the amount of the weld bead at the corner W3 tends to be insufficient (so-called corner drop).

In the welding apparatus 1, the process of moving the welding tool 17 is performed by moving the welding tool 17 along the extended portion W1 from a position a distance L3 away from the corner W3 to reaching the corner W3. Retreat processing for retracting the welding tool 17 in a direction away from the groove of the welded portion W, and while the welding tool 17 moving along the extended portion W2 moves away from the corner W3 to a position separated from the corner W3 by a distance L4. and advance processing for advancing the welding tool 17 by the amount retreated in the retreat processing. As a result, the position of the welding tool 17 when the tip of the welding tool 17 directly faces the corner W3 is separated from the groove of the welded portion W, so that a weld bead having a protruding shape at the corner W3 is easily formed. . Therefore, it is possible to suppress the angle drop of the weld bead.

In the welding device 1, the control unit 13 controls the robot 9B to stop the movement of the welding tool 17 for a predetermined time after changing the orientation of the welding tool 17 from the first state to the second state. After further execution and movement is stopped for a predetermined time, the orientation of the welding tool 17 is changed from the second state to the third state. As a result, a sufficient amount of weld metal is secured at the corner portion W3 by temporarily stopping the movement of the welding tool 17 . Therefore, it is possible to suppress the angle drop of the weld bead.

The above embodiment describes one embodiment of the field welding apparatus according to the present invention. The field welding device according to the present invention can be any modification of the welding device 1 described above.

For example, although the robots 9A and 9B are of the same type in the above embodiment, the robots 9A and 9B may be of different types. Moreover, it is not essential that the welding device 1 has two robots 9, and the number of the robots 9 may be one. In this case, it suffices if the end effector of one robot 9 is selectively replaceable. In the sensing process, the robot 9 may be provided with the groove sensor 15 to function as a sensing robot, and in the welding process, the robot 9 may be provided with the welding tool 17 to function as a welding robot. Alternatively, both the groove sensor 15 and the welding tool 17 may be attached to the arm tip of one robot 9 . In this case, the robot 9 may function as a sensing robot using the groove sensor 15 in the sensing process and as a welding robot using the welding tool 17 in the welding process.

Also, the method of determining zone allocation, block allocation, and path allocation described in the above embodiment is an example, and may be changed as appropriate. For example, in the above-described embodiment, a series of pass divisions are performed for all regions within the target groove cross section, but pass division may be performed for each of a plurality of regions within the target groove cross section. For example, path division may be performed for each of the region on the far side and the region on the front side in the target groove cross section. At this time, each layer may be set such that the outermost layer of the region on the far side extends vertically. This makes it possible to simplify the operation of the welding tool 17 for welding the near side area.

Further, in the pass allocation process, the control unit 13 may set the pass cross section P number to be common to all the groove cross sections, and then perform pass allocation to each groove cross section according to the pass cross section P number. The control unit 13 first performs pass division for a special groove cross-section (for example, a groove cross-section with the largest area or a groove cross-section with the smallest area, etc.), and sets the pass cross-section P as the groove cross-section. The number may be set to a pass cross-section P number that is common to all groove cross-sections, and the other groove cross-sections may be divided according to the pass cross-section P number. At this time, the pass allocating unit 34 may divide the groove cross section (e.g., evenly divide) according to the number of layers and the number of stages of the common pass cross section P to divide the groove into passes.

Also, the welded section described in the above embodiment is an example, and may be changed as appropriate. For example, in the above embodiment, the welded section includes the corner Wc, but it may be a straight welded section that does not include the corner Wc. For example, in the objects to be welded such as the column parts 3A and 3B, two erections (the erection piece 5 and the erection jig 7) are provided so as to straddle the groove at different positions of one side surface Ws. may have been In this case, the groove may be set as a welding section from a position covered by one of the two erections to a position covered by the other erection. As an example of setting such a welding section, there is a case where column parts 3A and 3B as objects to be welded constitute a column with a large cross section.

Further, for example, when welding a linear welding section that does not include the corner Wc as described above, the control unit 13 moves the robot 9B to a position facing the side surface Ws (for example, two The robot 9B may be moved to a position facing the center between the erections). The controller 13 may control the robot 9B to weld the welding section while the robot 9B is stopped at this position. Similarly, in the process of moving the robot 9A, the control unit 13 moves the robot 9A to a position facing the side surface Ws (for example, a position facing the center between two erections), and moves the robot 9A to this position. The robot 9A may be controlled to sense the groove of the welded section while it is stopped.

DESCRIPTION OF SYMBOLS 1... Welding apparatus (field welding apparatus), 9, 9B... Robot (welding robot), 13... Control part, 17... Welding tool (welding torch), L1... Distance (first distance), L2... Distance (second distance) ), L3 ... distance (third distance), L4 ... distance (fourth distance), W ... welded portion, W1 ... extension portion (first extension portion), W2 ... extension portion (second extension portion ), W3... corners.

Claims (3)

a welding robot having a welding torch for arc welding;
A corner portion, a first extension portion extending from the corner portion along a first direction, and a second extension portion extending from the corner portion along a second direction intersecting the first direction. a control unit that controls the welding robot to weld the welded part;
The control unit
a process of controlling the welding robot to move the welding torch in order of the first extending portion, the corner portion, and the second extending portion along the extending direction of the portion to be welded;
a process of controlling the welding robot to cause the welding torch to continuously generate an arc discharge while the welding torch moves in the order of the first extending portion, the corner portion, and the second extending portion; ,
A first state in which the tip of the welding torch intersects the first direction, a second state in which the tip of the welding torch faces the groove of the corner, and a tip of the welding torch intersects in the second direction. and a process of controlling the welding robot to sequentially change the orientation of the welding torch between a third state and a third state,
In the process of controlling the welding robot to sequentially change the orientation of the welding torch,
While the welding torch moving along the first extending portion reaches the corner from a position separated from the corner by a first distance, the welding relative to the moving direction of the welding torch is performed. the orientation of the torch is gradually changed to gradually change the orientation of the welding torch from the first state to the second state;
an orientation of the welding torch relative to a moving direction of the welding torch while the welding torch moving along the second extension moves away from the corner to a position a second distance away from the corner; is gradually changed to gradually change the orientation of the welding torch from the second state to the third state. a welding robot having a welding torch for arc welding;
A corner portion, a first extension portion extending from the corner portion along a first direction, and a second extension portion extending from the corner portion along a second direction intersecting the first direction. a control unit that controls the welding robot to weld the welded part;
The control unit
a process of controlling the welding robot to move the welding torch in order of the first extending portion, the corner portion, and the second extending portion along the extending direction of the portion to be welded;
a process of controlling the welding robot to cause the welding torch to continuously generate an arc discharge while the welding torch moves in the order of the first extending portion, the corner portion, and the second extending portion; ,
A first state in which the tip of the welding torch intersects the first direction, a second state in which the tip of the welding torch faces the groove of the corner, and a tip of the welding torch intersects in the second direction. and a process of controlling the welding robot to sequentially change the orientation of the welding torch between a third state and a third state,
In the process of controlling the welding robot to sequentially change the orientation of the welding torch,
While the welding torch moving along the first extending portion reaches the corner from a position separated from the corner by a first distance, the orientation of the welding torch changes from the first state to the gradually changed to the second state,
The orientation of the welding torch is changed from the second state to the third state while the welding torch moving along the second extension moves away from the corner to a position separated from the corner by a second distance. gradually changed to
The process of moving the welding torch includes:
While the welding torch moving along the first extending portion reaches the corner from a position separated from the corner by a third distance, the welding torch moves away from the groove of the welded portion. a retreating process for retreating the welding torch;
While the welding torch moving along the second extension moves away from the corner to a position separated from the corner by a fourth distance, the welding torch is moved forward by the amount retreated in the retreating process. field welding equipment, including processing and; a welding robot having a welding torch for arc welding;
A corner portion, a first extension portion extending from the corner portion along a first direction, and a second extension portion extending from the corner portion along a second direction intersecting the first direction. a control unit that controls the welding robot to weld the welded part;
The control unit
a process of controlling the welding robot to move the welding torch in order of the first extending portion, the corner portion, and the second extending portion along the extending direction of the portion to be welded;
a process of controlling the welding robot to cause the welding torch to continuously generate an arc discharge while the welding torch moves in the order of the first extending portion, the corner portion, and the second extending portion; ,
A first state in which the tip of the welding torch intersects the first direction, a second state in which the tip of the welding torch faces the groove of the corner, and a tip of the welding torch intersects in the second direction. and a process of controlling the welding robot to sequentially change the orientation of the welding torch between a third state and a third state,
In the process of controlling the welding robot to sequentially change the orientation of the welding torch,
While the welding torch moving along the first extending portion reaches the corner from a position separated from the corner by a first distance, the orientation of the welding torch changes from the first state to the gradually changed to the second state,
The orientation of the welding torch is changed from the second state to the third state while the welding torch moving along the second extension moves away from the corner to a position separated from the corner by a second distance. gradually changed to
The control unit
after changing the direction of the welding torch from the first state to the second state, further executing processing for controlling the welding robot to stop the movement of the welding torch for a predetermined time;
The field welding device, wherein the orientation of the welding torch is changed from the second state to the third state after movement is stopped for the predetermined time.

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