JP3649562B2 - Pipe MAG welding method and welder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nozzle MAG (MAG; Metal Active Gas) welding method and a welding machine applied to the mounting of a drum nozzle of various large structures.
[0002]
[Prior art]
As shown in FIG. 13, 150 to 200 nozzles 2 are attached to the boiler drum by welding at a pitch that is long in the longitudinal direction and the circumferential direction of the boiler drum 1.
[0003]
In the mounting of the nozzle 2 of the conventional boiler drum 1, the groove to be welded is an ordinary wide groove 3a as shown in FIG. 14, and it is necessary to perform a plurality of passes of welding in the width direction of the groove 3a. Since the inclination angle of the welding torch had to be adjusted for each pass, continuous welding could not be performed. Moreover, automation was not possible because the pitch of the nozzle 2 was small and the welding torch contacted the adjacent pipe.
[0004]
For this reason, the mounting of the nozzle 2 of the conventional boiler drum 1 shown in FIG. 14 has been performed by semi-automatic MAG welding that requires manual work by a highly skilled worker.
[0005]
[Problems to be solved by the invention]
In the installation of a conventional boiler drum nozzle, the inclination angle of the welding torch must be adjusted for each pass in the groove width direction for welding as described above, and continuous welding cannot be performed. Semi-automatic MAG welding has been adopted because it cannot be automated because the torch contacts an adjacent pipe.
[0006]
However, this semi-automatic MAG welding requires a highly skilled worker, and there is a limit to improvement in welding quality and work efficiency, and realization of automatic MAG welding has been desired.
The present invention seeks to solve the above problems.
[0007]
[Means for Solving the Problems]
(1) The nozzle MAG welding method of the present invention forms a parallel chamfer that makes a round around the nozzle provided in the attachment member and is inclined toward the center of the nozzle, and is attached around the nozzle. An auxiliary shield ring is provided on the surface of the member, a welding machine is provided on the nozzle, and the tip of the welding torch with a curved tip provided at the tip is inserted into the groove and directed toward the groove. After starting the discharge of shield gas from the auxiliary shield ring, adjust the oscillating width and stop time at both ends, rotate the welding torch and oscillate the tip of the welding wire with the curve tip, and around the nozzle The swiveling welding torch starts turning and performs welding in the groove. When the welding torch makes one turn, the oscillating is stopped, the welding current is reduced and the welding torch is reversed, and the oscillating is performed after the welding torch is reversed. The welding current is reduced and the welding current is restored, the welding torch is swung in the opposite direction, and the welding torch is swung and reversed repeatedly to stack the weld metal in the groove, and to the pipe to the mounted member It is characterized by mounting the base.
[0008]
In the present invention, the welding torch that turns around the center of the nozzle pedestal is inclined at an angle that does not contact the adjacent pipe, and forms a parallel groove that goes around the nozzle pedestal. It becomes possible to laminate a weld metal up to the surface under certain welding conditions.
[0009]
Also, when the welding torch turns and starts welding from the welding start point and returns to the starting point again, the welding is reversed without interruption, and the welding torch can turn and run in the opposite direction. Since traveling and reversal can be repeated, continuous welding can be performed.
[0010]
Further, since the groove to be welded is sealed by the shield gas discharged from the auxiliary shield ring, the tip of the welding wire is connected to the tip of the welding torch by the rotation of the welding torch and the curve tip provided at the tip of the welding torch. Oscillation is performed by drawing a circular arc directed in the traveling direction, and the oscillation width and the stop time at both ends thereof can be controlled. Therefore, it is possible to realize good welding with sufficient penetration and stable quality.
[0011]
(2) The nozzle MAG welder of the present invention is attached to a clamp jig inserted into the nozzle and fixed to the nozzle, a turning mechanism fitted and fixed to the clamp jig, and an upper part of the turning mechanism. A slip ring mechanism, a horizontal slide attached to the side of the turning mechanism, a wire protrusion length control slide provided at one end of the horizontal slide, a welding torch provided in the wire protrusion length control slide, and Provided with a wire feeding mechanism mounted on the other end of the horizontal slide The pivot mechanism is provided with a hollow shaft having a spur gear coupled to the clamp jig, a base plate joined to the hollow shaft via a bearing and connected to the horizontal slide, and the base plate. A turning drive mechanism connected to the spur gear and a turning position detection sensor provided on the base plate are provided, and the slip ring mechanism has a current-carrying portion, a cooling water passage portion, and a shield gas ventilation portion. It is characterized by that.
[0012]
In the present invention, since the clamp jig that is fixed to the nozzle and capable of fixing the turning mechanism is provided, the clamp jig is fixed to the nozzle, and then it is easily welded by fixing the turning mechanism thereto. The machine can be attached to the nozzle.
[0013]
Further, a horizontal slide is attached to the turning mechanism, and a welding torch is provided at one end of the horizontal slide via a wire protrusion length control slide. By adjusting, the welding torch can be tilted at an angle that does not contact the adjacent nozzle, and the tip thereof can be inserted into a groove provided around the nozzle and set.
[0014]
In addition, since the wire feeding mechanism for automatically feeding the wire to the welding torch is provided at the other end of the horizontal slide, the turning mechanism turns the horizontal slide and reverses every round. By returning, it is possible to perform the lamination continuous welding in the groove by the welding torch.
[0015]
Furthermore, since the current, cooling water, and shielding gas are supplied to the welding torch through a slip ring mechanism provided at the upper part of the turning mechanism, good energization, cooling of the welding torch, and welding are performed. The part can be sealed, and in particular, there is no water leakage and good welding is possible.
[0016]
In the present invention, the swivel mechanism includes a hollow shaft, a base plate that is swiveled and reversed by a swivel drive mechanism, and a swivel position detection sensor for the base plate. Turn and turn possible .
[0017]
In addition, since the slip ring mechanism includes the energization part, the water flow part, and the ventilation part, it is possible to energize the welding torch well, cool the welding torch, and seal the welding part.
[0018]
(3) The present invention In the nozzle MAG welding machine according to the invention (2), the wire protrusion length control slide includes a rotating plate that makes the mounting angle to the horizontal slide variable, and the welding torch includes the wire protrusion. A torch body coupled to the long control slide, an outer cylinder penetrating the torch body, a curve tip provided at the tip of the outer cylinder, and a welding wire provided in the outer cylinder and supplied to the curve tip An inner cylinder that passes through the inner cylinder, and a rotational drive mechanism that is provided in the torch body and repeatedly rotates the outer cylinder. It is characterized by having.
[0019]
In the present invention, The rotation drive mechanism turns the outer cylinder repeatedly, so that the tip of the curve tip draws an arc in the direction of travel, and the tip of the welding wire performs an arc-shaped oscillating operation. Can be melted and welded well. .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
A welding apparatus applied to the implementation of a nozzle drum nozzle MAG welding method according to an embodiment of the present invention will be described with reference to FIG. .
[0021]
A welding apparatus applied to the welding method according to the present embodiment shown in FIG. 1 includes a clamp jig 4 fitted into a nozzle 2 provided on a boiler drum 1, and a jig 4 provided on the jig 4. As a horizontal slide 5 that swivels horizontally .
[0022]
Further, a welding machine provided with a wire protrusion length control slide 6 disposed on the horizontal slide 5 and a welding torch 7 into which a tip 8 disposed at the tip of the control slide 6 is inserted into the groove 3 is provided. Have .
[0023]
Also, The nozzle 2 is formed by the auxiliary shield ring 9 that is disposed on the surface of the boiler drum 1 with the same central axis and discharges shield gas.
[0024]
Next, a nozzle MAG welding method according to this embodiment performed using the above-described welding apparatus will be described with reference to FIGS. In the welding method according to the present embodiment shown in FIGS. 1 to 5, the angle at which the tip is inserted in advance and the welding torch 7 turning around the center of the nozzle 2 around the center does not contact the adjacent pipe. As shown in FIG. 2, a parallel cleavage groove 3 that is inclined and goes around the nozzle 2 is formed.
[0025]
Next, after the auxiliary shield ring 9 is disposed on the surface of the boiler drum 1 with the central axis of the nozzle 2 as the center, the clamp jig 4 is fitted into the nozzle 2 and a welding machine is attached. Is inserted into the groove 3.
[0026]
In this state, as shown in FIG. 3, after the discharge of the shield gas 18 from the auxiliary shield ring 9 toward the center part of the nozzle 2 and the direction of the groove 3 is started, welding by the welding torch 7 is started. 4, while oscillating with the tip 8 as shown in FIG. 4, the welding torch 7 is turned by the horizontal slide 5 to make one turn around the nozzle 2, and the reversing position (from the start point 16 shown in FIG. 5 in the groove 3 ( Weld up to 17) (same position as start point 16).
[0027]
When the welding torch 7 reaches the reversal position 17, the oscillating by the tip 8 is stopped, the welding current is reduced, and the welding torch 7 is reversed at a high speed as shown in FIG. After reversing the welding torch 7, the height of the welding torch 7 is adjusted by the wire protrusion length control slide 6 to a height corresponding to the rise of the weld metal 13, the reduced welding current is restored, and the oscillating rate is resumed. The welding torch 7 is turned around in the opposite direction to perform welding.
[0028]
When the welding torch 7 turns and reverses continuously, the welding metal 13 is laminated in the groove 3, and when the height of the laminated welding metal 13 reaches a predetermined height, the boiler drum The welding for mounting the nozzle 2 to 1 is completed.
[0029]
The details of the oscillation by the tip 8 performed during the welding by the welding torch 7 will be described below with reference to FIG. The tip 8 is attached to the tip of the welding torch 7, the tip of the tip 8 is bent toward the traveling direction 15 of the welding torch 7, and the tip is turned left and right by the rotation of the welding torch 7 to draw an arc. The welding wire 10 sent from the torch 7 is sent out from the tip.
[0030]
Therefore, the tip of the welding wire 10 delivered from the tip 8 oscillates while drawing an arc in the traveling direction 15 of the welding torch 7 having a predetermined oscillating width 12, and generates an arc 14 from the tip.
[0031]
Note that the rotation angle 11 of the welding torch 7 that determines the oscillating width 12 of the welding wire 10 and the rotation stop time of the welding torch 7 at both ends of the arc drawn by the tip of the welding wire 10 can be appropriately controlled. Yes.
[0032]
In the present embodiment, the welding torch that turns about the center of the nozzle pedestal is inclined at an angle that does not contact the adjacent pipe, and forms a parallel groove that goes around the nozzle pedestal. It became possible to laminate metal under constant welding conditions from the bottom to the surface.
[0033]
Also, the tip of the wire is bent in the direction of travel of the welding torch by bending the tip, and oscillates by turning the welding torch to the left and right to draw an arc, and the oscillating width and stop time at both ends are Since it was able to be controlled appropriately, it was possible to ensure sufficient penetration of the weld metal and stable quality, and good welding was possible.
[0034]
Also, welding is performed by turning the welding torch from the welding start point and returning to the starting point. When the welding torch is returned to the starting point again, the welding is reversed without interruption, and the welding is performed by turning in the opposite direction to repeat the welding. Therefore, continuous welding in which the weld metal is continuously laminated in the groove becomes possible.
[0035]
Furthermore, an auxiliary shield ring is installed on the surface of the boiler drum on the outer periphery of the nozzle, and shield gas is discharged from this ring toward the center of the nozzle and the direction of the groove to prevent air from entering from the outer surface and the upper surface. Good welding was possible because the shield in the groove was kept good.
[0036]
Next, a welding machine applied to the implementation of the nozzle MAG welding method according to the present embodiment will be described specifically and in detail below with reference to FIGS. In addition, this welding machine is attached to the nozzle 2 provided in the boiler drum 1 shown in FIG.
[0037]
The overall structure of the present welding machine is shown in FIG. 6 and the mounting operation to the nozzle 2 is shown in FIG. 7. In mounting to the nozzle 2, first, FIG. The clamp jig 4 is fitted into the nozzle 2 as shown in FIG. 7, and then the welding machine is attached to the nozzle 2 by fixing the turning mechanism 104 to the clamp jig 4 as shown in FIG. .
[0038]
A slip ring mechanism 105 is provided on the upper part of the turning mechanism 104, and electricity is supplied to the electrical system and cooling water and shield gas are supplied through the slip ring mechanism 105. A wire protrusion length control slide 6 is provided at one end of the horizontal slide 5 attached to the side surface of the turning mechanism 104, and the tip of the welding torch 7 attached thereto is inserted into the groove.
[0039]
A wire feed motor 109, a wire reel 110, and the like are mounted on the other end portion of the horizontal slide 5. As shown in FIG. 7C, a welding wire is connected from the wire reel 110 via a conduit cable 111. Is fed to the welding torch 7, and after the arc starts, the welding torch 7 turns while oscillating to perform continuous welding.
[0040]
The details of the clamp jig 4 will be described with reference to FIG. The clamp jig 4 is fixed to the nozzle 2 by fitting the clamp body 112 to the nozzle 2 and then rotating the handle 113 to raise the taper block 115 via the shaft 114 and widen the clamp piece 116. Done.
[0041]
The removal is performed after the handle 113 is turned in the opposite direction and the clamp piece 16 is accommodated by the tension coil spring 117 provided around the clamp piece 116. 118 is a guide plate, and 119 is a knob.
[0042]
The details of the turning mechanism 104 will be described with reference to FIG. The welding machine can be held by inserting the hollow shaft 20 of the turning mechanism 104 into the clamp jig 4 fitted in the nozzle 2 and fixing it with the clamp lever 21. A spur gear 22 is fastened and fixed to the hollow shaft 20 by a bearing nut 23, and a housing 25 and a base plate 26 are attached via a bearing 24.
[0043]
A gear case 27 is attached to the base plate 26, and a spur gear 32 is rotated via bevel gears 29 and 30 and a shaft 31 by driving a turning motor 28. The spur gear 32 is screwed with the spur gear 22. Since the spur gear 22 is fixed, the spur gear 32 rotates around the spur gear 22 when the spur gear 32 rotates, and the base plate 26 rotates.
[0044]
The proximity switch 33 provided on the base plate 26 is for detecting the origin when turning, and detects the origin by detecting the dog 34 attached to the spur gear 22. Further, the proximity switch 35 is for detecting the turning position, and detects the turning position by detecting the number of teeth of the spur gear 22 and is important in setting welding conditions and welding work, respectively. Reference numeral 36 denotes a gear cover.
[0045]
The base plate 26 is provided with a frame formed of an L-shaped support 37, a plate 38, and a bracket 39, and the horizontal slide 5 is incorporated and fixed in the frame.
[0046]
The slip ring mechanism 105 will be described in detail with reference to FIG. The slip ring mechanism 105 is attached and fixed to the upper surface of the hollow shaft 20 of the turning mechanism 104, and has a structure capable of supplying electricity to the electrical system and supplying cooling water and shielding gas.
[0047]
The power cable 40 from the welding power source passes through the hollow shaft 57 from above and is fixedly attached to the energizing bolt 41. The welding current is passed through the energizing ring 42, the brush 43, the energizing ring 44, the energizing shoe 45, and the energizing bolt 46. The current flows to the energization block 46 ', and is further energized from there to the welding torch.
[0048]
Six energization shoes 45 are provided around the energization ring 44 at equal intervals, and the energization ring 42 is evenly pressed by the spring 48 in the spring holder 47 so that good energization can be performed.
[0049]
The turning mechanism 104 is attached by attaching an insulating flange 50 incorporating an O-ring 49 to the upper surface of the hollow shaft 20 of the turning mechanism 104, and a hollow rotor 51 is attached on the insulating flange 50 via a bearing 52. A housing 53 and an insulating ring 54 are attached to form an insulating structure with the hollow rotor 51 on the fixed side.
[0050]
Further, a hollow shaft 57 is attached and fixed to the upper surface of the hollow rotor 51 via an insulating flange 56, and a slip ring 58 for energizing an electric system is fitted to the outside of the hollow shaft 57 and fixed by a ring 59. Reference numeral 60 denotes a slip ring cover, and 61 denotes a non-rotating guide shaft, which is fixed to the insulating flange 55.
[0051]
Further, the turning mechanism 104 is connected to the turning mechanism 104 by the guide shaft 62 and the bracket 63 attached to the side surface of the insulating flange 55, and the rotating side including the insulating flange 55 rotates together with the base plate 26 of the turning mechanism 104. The above-mentioned energization part is attached to the insulating flange 55.
[0052]
The hollow rotor 51 on the fixed side is provided with a shield gas feed hole and groove for communicating the shield gas feed pipes 106 and 107, and an O-ring 54 is attached in five stages, each rotating. It is sealed with the housing 53 which is the side.
[0053]
As shown in FIG. 10 (b), the other end of the cooling water supply pipe 101 and the other end of the cooling water drain pipe / feeding cable 102 connected to the welding torch 7 are connected to the energizing block 46 ′. Cooling water is circulated with the cooling water supply device that does not. This cooling water system is characterized by a seal that is almost free from water leakage.
[0054]
The wire protrusion length control slide 6 will be described in detail with reference to FIG. The wire protrusion length control slide 6 is attached to the horizontal slide 5 fixed to the turning mechanism 104 with a circular rotating plate 65, and has a structure capable of adjusting the inclination angle according to the nozzle groove angle.
[0055]
A base plate 66 is fixed to the rotary plate 65, and a screw shaft 68 is rotated by a vertical drive motor 67 attached to an end of the base plate 66, so that a slider 69 moves up and down. Reference numeral 70 denotes a linear motion (LM) guide that smoothly moves the slider 69 up and down.
[0056]
Docks 71 and 72 are attached to the side surface of the slider 69, and the upper and lower ends are detected by proximity switches 73a and 73b. Further, the proximity switch 74 is for initial setting of the torch position. When the apparatus is set, the tip of the welding torch 7 attached to the bracket 75 of the slider 69 can be guided and positioned in the groove.
[0057]
The details of the welding torch 7 will be described with reference to FIG. The torch body 76 is attached to the wire protrusion length control slide 6 by the bracket 75 described above. A torch inner cylinder 79 and a torch outer cylinder 80 incorporating an inner tube 78 insulated by an insulating bush 77 are inserted into the torch body 76.
[0058]
The aforementioned conduit cable 111 is connected to the upper joint 81, and the welding wire 10 that has passed through the rotary shaft 82 passes through the torch inner cylinder 79 and into the curve tip 84 fixed to the torch outer cylinder 80 by the lock nut 83. Be sent. Reference numeral 85 denotes a locking key.
[0059]
Two shield nozzles 86a and 86b are inserted into the front and rear of the torch outer cylinder 80 at the lower portion of the torch main body 76, and are fixed by a nozzle holder 87. The torch main body 76 passes through the slip ring mechanism 105 from the outside. By supplying the shield gas that has passed through to the periphery of the curve chip 84, the shielding effect during welding is further enhanced.
[0060]
The cooling water is supplied from the cooling water supply pipe 101 to the gap between the torch inner cylinder 79 and the inner tube 78 shown in FIG. 12 (c), descends this gap to reach the lower end, and the inner from the lower end. The gap between the tube 78 and the torch outer cylinder 80 is raised and drained to the cooling water drain pipe / feeding cable 102, and the welding torch 7 is effectively cooled.
[0061]
In the upper part of the torch body 76, a rotary motor 90 is provided on a motor base 89 attached to a casing 88. When the rotary motor 90 is driven, its rotation is rotated via a timing pulley 91 and a timing belt 92. Then, the welding torch 7 is rotated and oscillated.
[0062]
The rotation angle is detected by a potentiometer 96 attached via a joint shaft 94 and a coupling 95 directly connected to the rotary motor 90. 97 is a potentio case, and 98 is a cover.
[0063]
When the welding of the nozzle 2 to the boiler drum 1 is performed using the main welding machine, the turning mechanism 104 of the main welding machine is fixed to the clamp jig 4 fitted in the nozzle 2, and the center of the nozzle 2 is fixed. The welding torch 7 tilted at an angle that does not contact the adjacent nozzle 2 can be inserted and set in the groove by making the rotation center parallel to the groove angle of the nozzle 2.
[0064]
Further, the turning mechanism 104 can be turned around the center of the nozzle 2 as a turning center, and the slip ring mechanism 105 is connected to the outside from the welding power source, the control panel, etc. Supply can be made.
[0065]
In this slip ring mechanism 105, countermeasures against water leakage are the most important. However, the rotor 51 on the fixed side is provided with five stages of O-rings 64, and each is sealed with the housing 53 on the rotation side, thereby water leakage. Since the seal is almost non-existent, good swirl continuous welding can be performed.
[0066]
When the shape dimension of the nozzle 2 changes, the radial direction is adjusted with the horizontal slide 5 and the inclination angle with respect to the nozzle axis is adjusted with the rotation mechanism of the wire protrusion length control slide 6. It can be easily handled.
[0067]
In addition, the torch height of the weld metal stack is controlled by controlling the welding current according to the wire protrusion length, and moving to the surface layer sequentially by the wire protrusion length control slide 6 so that the continuous welding to the upper layer is possible without interruption. can do.
[0068]
Further, in order to obtain a good shield against a narrow groove shape in a narrow space, an oval shield nozzle 86 is provided on the torch body 76 of the welding torch 7 in the welding progress direction, so that the shield in the groove is good. Can be kept in.
[0069]
Based on the above, setting is simplified by adopting the one-touch fixing method on the inner surface of the nozzle, torch position control by mounting a lightweight and stable copying mechanism (adopting arc current control), 1 layer 1 pass by narrow groove, laminating method Simplification has become possible, and it has become possible to shorten the welding work time and man-hours.
[0070]
【The invention's effect】
In the nozzle MAG welding method of the present invention, a parallel groove is formed around the nozzle, and discharge of shield gas from the auxiliary shield ring toward the groove is started, and then the rotation of the welding torch and the curve tip are started. The arc is drawn at the tip of the welding wire to make the welding torch swivel while oscillating while performing welding in the groove, and when the welding torch makes a round around the nozzle base, it is reversed and swiveled in the opposite direction, By repeating this, the weld metal is laminated in the groove, and the nozzle is attached to the member to be mounted. By adopting a parallel groove, the welding torch is inverted every round. Since it is made to turn, automatic MAG welding is possible, and high-efficiency welding can be performed.
[0071]
In addition, the shield gas is blown from the auxiliary ring toward the groove, and welding is performed while an arc is drawn on the tip of the welding wire, so that high-quality welding is possible. The size and robustness can be achieved, and the reliability of the apparatus can be improved.
[0072]
Further, the nozzle MAG welding machine of the present invention includes a clamp jig, a turning mechanism, a slip ring mechanism, a horizontal slide, a wire protrusion length control slide, a welding torch, and a wire feeding mechanism. As a result, a welding machine that can be easily attached to the nozzle and can perform the above-described welding method is realized.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a welding apparatus applied to a nozzle MAG welding method according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a groove shape according to the embodiment.
FIG. 3 is an explanatory diagram of shield gas discharge according to the embodiment.
FIGS. 4A and 4B are explanatory diagrams of the oscillate at the tip of the welding wire according to the embodiment, where FIG. 4A is a side view and FIG.
FIGS. 5A and 5B are explanatory diagrams of the turning traveling of the welding torch according to the embodiment, where FIG. 5A is a plan view, FIG. 5B is a view taken along arrow B-B in FIG. 5A, and FIG. CC arrow figure, (d) is explanatory drawing just before inversion of a welding torch, (e) is explanatory drawing at the time of inversion.
FIG. 6 is a front view of a nozzle MAG welder according to an embodiment of the present invention.
FIGS. 7A and 7B are explanatory diagrams of a mounting operation procedure of the nozzle MAG welding machine according to the embodiment, wherein FIG. 7A is a clamp jig installation, FIG. 7B is a turning mechanism installation, and FIG. 7C is a welding torch; Insertion into groove, (d) is an explanatory view of arc start.
8A and 8B are explanatory views of the clamp jig according to the embodiment, wherein FIG. 8A is a side sectional view, and FIG. 8B is a view taken along the line DD in FIG.
FIG. 9 is a side sectional view of the turning mechanism according to the embodiment.
10A and 10B are explanatory views of the slip ring mechanism according to the embodiment, wherein FIG. 10A is a side sectional view, and FIG. 10B is a functional explanatory view of a current-carrying block.
11A and 11B are explanatory diagrams of the wire protrusion length control slide according to the embodiment, where FIG. 11A is a plan view and FIG. 11B is a view taken along the line E-E in FIG.
FIGS. 12A and 12B are explanatory diagrams of the MAG welding torch according to the embodiment, where FIG. 12A is a front view, FIG. 12B is a view taken along the line FF in FIG. 12A, and FIG. FIG.
13A and 13B are explanatory views of a boiler drum, in which FIG. 13A is an overall side view, and FIG. 13B is an enlarged cross-sectional view of a portion H in FIG.
FIG. 14 is an explanatory view of a groove in a conventional welding method.
[Explanation of symbols]
1 Boiler drum
2 nozzle
3 groove
4 Clamp jig
5 Horizontal slide
6 Wire protrusion length control slide
7 Welding torch
8 chips
9 Auxiliary shield ring
10 Welding wire
11 Torch rotation angle
12 Oscillate width
13 Weld metal
14 arc
15 Direction of travel
16 Starting point
17 Reverse position
18 Shielding gas
20 hollow shaft
22 Spur gear
24 Bearing
26 Base plate
28 Rotating motor
29,30 Bevel gear
31 axes
32 spur gear
33, 35 Proximity switch
40 Power cable
41 Power supply bolt
42 Energizing ring
43 Brush
44 Energizing ring
45 Electric shoe
46 Power supply bolt
46 'electricity block
50 Insulation flange
51 Hollow rotor
52 Bearing
57 Hollow shaft
58 slip ring
64a ~ e O-ring
65 rotating plate
66 Base plate
67 Vertical drive motor
69 slider
73a, b, 74 Proximity switch
76 Torch body
78 Inner tube
79 Torch inner cylinder
80 Torch outer cylinder
84 Curve tip
86a, b Shield nozzle
90 Rotating motor
91, 93 Timing pulley
96 Potentiometer
101 Cooling water supply pipe
102 Cooling water drainage pipe and power supply cable
104 Turning mechanism
105 Slip ring mechanism
106,107 Shield gas supply pipe
109 Wire feed motor
110 wire reel
111 conduit cable
112 Clamp body
114 shaft
116 Clamp piece
117 Extension coil spring

Claims (3)

  A parallel crevice that makes a round around the nozzle provided on the attached member and tilts toward the center of the nozzle is formed, and an auxiliary shield ring is provided on the attached member surface around the nozzle, and the nozzle The tip of the welding torch with a curved tip provided on the tip was inserted into the groove, and discharge of shield gas from the auxiliary shield ring toward the groove was started. Then, while rotating the welding torch and oscillating the tip of the welding wire with the curve tip by adjusting the oscillating width and the stop time at both ends, the welding torch turning around the nozzle is started and the above opening is started. Weld in the tip, stop the oscillation when the welding torch makes a full circle, reduce the welding current, reverse the welding torch, restart the oscillating after the welding torch is reversed, and restore the reduced welding current. The welding torch is swung in the opposite direction, and the welding torch is repeatedly swung and reversed so that the weld metal is laminated in the groove and the nozzle is attached to the mounted member. The nozzle MAG welding method.   Clamp jig inserted into the nozzle and fixed to the nozzle, swivel mechanism fitted and fixed to the clamp jig, slip ring mechanism attached to the top of the swivel mechanism, attached to the side of the swivel mechanism Horizontal slide, a wire protrusion length control slide provided at one end of the horizontal slide, a welding torch provided at the wire protrusion length control slide, and a wire mounted at the other end of the horizontal slide A hollow shaft having a spur gear and coupled to the clamp jig, and a base plate joined to the hollow shaft via a bearing and connected to the horizontal slide. A slip ring machine comprising: a turning drive mechanism provided on a base plate and connected to the spur gear; and a turning position detection sensor provided on the base plate. But energizing portion and a water passing portion of the cooling water, the nozzle MAG welder, characterized in that it comprises a vent of the shield gas. 3. The nozzle MAG welding machine according to claim 2, wherein the wire protrusion length control slide includes a rotating plate that can change an attachment angle to the horizontal slide, and the welding torch is connected to the wire protrusion length control slide. A joined torch body, an outer cylinder passing through the torch body, a curve tip provided at the tip of the outer cylinder, and a welding wire provided in the outer cylinder and supplied to the curve tip A nozzle MAG welding machine comprising a passing inner cylinder and a rotation drive mechanism provided in the torch body for repeatedly rotating the outer cylinder .

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