JP3204440B2 - Centering jig for welding pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centering jig for welding pipes, and more particularly, to constructing a furnace wall of a boiler furnace with a large number of furnace wall panels (piping panels). The present invention relates to a pipe centering jig used for welding heat transfer tubes (pipes) to each other.

[0002]

2. Description of the Related Art As shown in FIG. 11, a furnace wall of a boiler furnace 1 is a large can-made product composed of a rectangular container of several tens of meters.
It is constructed by welding and assembling a plurality of furnace wall panels formed in a predetermined size. As shown in FIG. 12, the furnace wall panel includes a plurality of heat transfer tubes 2, 2,.
..) Are connected in parallel at predetermined intervals by welding. In order to weld the opposed heat transfer tubes 2, 2,... Of the upper furnace wall panel 4A and the lower furnace wall panel 4B to each other, the blades 3 near the welded portion are necessary for the welding operation. The space is formed as short as the space, and this space is used as the welding work space 5. The welding work space 5 is formed at several thousands places in one boiler furnace, and is shielded by blades (not shown) after the welding work of the heat transfer tubes 2 and 2 is completed. This allows
The inside of the boiler furnace 1 becomes a sealed airtight container.

In the welding work space 5, the shaft cores of the opposed heat transfer tubes 2, 2 are eccentric, and the eccentric amounts thereof are also non-uniform. For this reason, when welding the heat transfer tubes 2, 2, it is necessary to center the heat transfer tubes 2, 2. As shown in FIGS. 13 and 14, the conventional centering jig uses a pair of pressing tools 6A and 6B each having a radially-divided arc-shaped groove. One pressing tool 6A is connected to the furnace wall panels 4A and 4B. And the other pressing member 6B is arranged inside the furnace wall panels 4A, 4B, and these pressing members 6A, 6B are tightened with bolts 7 to sandwich the heat transfer tubes 2, 2 between the pressing members 6A, 6B. By attaching, the misalignment of the heat transfer tubes 2 and 2 is corrected and centered.

[0004]

However, the conventional centering jig requires the work of attaching the pressing tools 6A and 6B to the welding work space 5 on both the outside and the inside of the furnace wall panels 4A and 4B. In addition, workers are required outside and inside the boiler furnace 1, thereby increasing the number of working steps and increasing the risk of the workers as the boiler furnace 1 is built higher.

Further, in the conventional centering jig, when the bolt 7 is loosened and the pressing tools 6A and 6B are removed, the pressing tool 6B detached from the bolt 7 may fall from a high place. There is a disadvantage that there is. The present invention has been made in view of such circumstances, and provides a pipe centering jig for pipes that can perform pipe centering work on one side surface of a pipe panel and has improved safety. With the goal.

[0006]

According to the present invention, in order to achieve the above-mentioned object, a plurality of piping panels of a predetermined size each having a plurality of pipes connected in parallel at predetermined intervals by connecting members are provided. In a welding centering jig for piping for welding panels to each other, a first centering reference groove in which a pipe end abuts on a peripheral surface of one of the pipes facing each other, A pedestal that is in contact with the peripheral surface of the other pipe and has a second centering reference groove formed in a straight line with the first centering reference groove; It is movably and slidably connected, is inserted into a space between the pipes near the welding portion at a predetermined rotation position, is rotated to a predetermined position, and slides toward the pedestal side. The first pipe is brought into contact with the one pipe by the A first pressing member that presses against the reference groove for dispensing, a rotatable and slidably connected to the pedestal, and a space between the pipes near the welding portion at a predetermined rotation position; And a second pressing that is rotated to a predetermined position and slid to the pedestal side to abut on the other pipe and press the other pipe against the second centering reference groove. And a tool.

According to the present invention, first, the first pressing tool and the second pressing tool are turned to a predetermined turning position, so that the pipe between the pipe near the welded portion from one side of the pipe panel. Into the space. Next, the first centering reference groove of the pedestal is brought into contact with the peripheral surface of one of the pipes, and the second centering reference groove is brought into contact with the peripheral surface of the other pipe. Next, one of the pipes is pressed against the first centering reference groove by the first pressing tool by rotating the first pressing tool to a predetermined rotation position and sliding the base to the pedestal side. Similarly, the second pressing member is also rotated to a predetermined rotation position and slid toward the pedestal, so that the other pipe is pressed against the second reference groove by the second pressing member. Thus, the axes of the two pipes to be welded are corrected and centered in the first and second reference grooves of the pedestal. Therefore, in the present invention, the centering operation of the pipe can be performed on one side surface of the pipe panel.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a centering jig for welding a pipe according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a heat transfer tube 1 of an upper furnace wall panel 12A using a centering jig 10 according to a first embodiment of the present invention.
It is a perspective view which shows the situation which centers 4A and the heat exchanger tube 14B of the lower furnace wall panel 12B for welding.

The vertical length of the welding work space 18 formed by the blades 16A of the furnace wall panel 12A and the blades 16B of the furnace wall panel 12B is determined by the furnace wall panel 12A and the furnace wall panel 1A.
A general method for calculating an empirical value of the amount of axial eccentricity of the heat transfer tubes 14A and 14B in the welded portion 20 with the 2B and a load (moment force) required to correct the amount of eccentricity by cold working. It is calculated and set from the calculation formula (Wl ³ / 3EI), data of the experimental test results, and the like. For example, heat transfer tube 1
In the case where the outer diameters of 4A and 14B are 38.1 mm, about 150 mm is required on one side from the welded portion 20, whereby the length of the welding work space 18 is set to about 300 mm.

The centering jig 10 includes a pedestal 22 and a pair of pressing tools 24 and 26. Two arc-shaped curved grooves 28A, 28B, 30 corresponding to the outer diameters of the heat transfer tubes 14A, 14B are provided on both sides in the longitudinal direction of the pedestal 22.
A and 30B are formed. The curved grooves (first centering reference grooves) 28A, 30A are in contact with adjacent heat transfer tubes 14A, 14A of the furnace wall panel 12A, and the curved grooves (second centering reference grooves) 28B, 30B are The heat transfer tubes 14B, 14B adjacent to the furnace wall panel 12B are in contact with the heat transfer tubes 14B, 14B, and have a pitch dimension substantially equal to the pitch size of the heat transfer tubes 14A, 14B. The curved groove 30A and the curved groove 30B
Centers of curvature P1 and P2 between the curved groove 28A and the curved groove 28B
(See FIG. 3) are formed on the same straight line. Similarly, the curved groove 30A and the curved groove 30B are formed such that their centers of curvature P3 and P4 (see FIG. 3) are located on the same straight line.

The material of the pedestal 22 may be steel, and can be easily manufactured by cutting or casting. The space 32 between the curved groove 28A and the curved groove 28B and the space 34 between the curved groove 30A and the curved groove 30B are windows for inserting a welding torch and visually confirming a welding situation, and a pedestal. It is also a window to reduce the weight of 22. A hole 36 is formed in the upper central portion of the pedestal 22, and the screw rod 38 of the pressing tool 24 is inserted into the hole 36. Also, the pedestal 22
A long hole 40 is formed in the lower central portion in the vertical direction, and the screw rod 42 of the pressing tool 26 is inserted into the long hole 40 so as to be vertically movable along the long hole 40.

On the other hand, the pressing tool 24 is formed in a flat plate shape, and its plate thickness is formed smaller than the width of the welding working space 18. The screw 3 of the pressing tool 24
8 is also formed to be smaller than the width of the welding work space 18. Thus, the pressing tool 24 can be inserted from the front side of the furnace wall panels 12A, 12B to the back side of the furnace wall panels 12A, 12B via the welding work space 18. Further, the pressing tool 24 is prevented from falling off from the pedestal 22 by a nut 44 attached to the screw rod 38 from the front side of the pedestal 22.

On both sides of the pressing member 24, arc-shaped curved grooves 48A and 50A corresponding to the outer diameter of the heat transfer tube 14A are formed. The curved grooves 48A, 50A are pressed against the backside of the heat transfer tubes 14A, 14A by being turned 90 ° after the pressing tool 24 is inserted into the backside of the furnace wall panels 12A, 12B via the welding work space 18. Touched. The pressing tool 26 has the same structure as the pressing tool 24 and is formed in a flat plate shape, and the thickness of the pressing tool 26 is smaller than the width of the welding working space 18. The diameter of the threaded rod 42 of the pressing tool 26 is also smaller than the width of the welding work space 18. Thereby, the pressing tool 26 can be inserted from the front side of the furnace wall panels 12A, 12B to the back side of the furnace wall panels 12A, 12B via the welding work space 18. Further, the pressing tool 26 is prevented from falling off from the pedestal 22 by a nut 46 attached to the screw rod 42 from the front side of the pedestal 22.

On both sides of the pressing member 26, arc-shaped curved grooves 48B and 50B corresponding to the outer diameter of the heat transfer tube 14B are formed. The curved grooves 48B and 50B are pressed against the backside of the heat transfer tubes 14B and 14B by being turned 90 ° after the pressing tool 26 is inserted into the backside of the furnace wall panels 12A and 12B via the welding work space 18. Touched. next,
With the centering jig 10 configured as described above, the heat transfer tubes 14A,
The operation of centering 14B will be described.

First, the front side of the furnace wall panels 12A, 12B,
Or one of the back sides (in this embodiment, the front side)
As shown in FIG. 2, the pressing tool 24 of the centering jig 10
26 is inserted into the welding work space 18, and the pressing tools 24, 26 are positioned on the back side of the furnace wall panels 12A, 12B. next,
The spaces 32 and 34 formed on both sides of the pedestal 22
The centering jig 10 is positioned so as to be located at the position of zero. Next, as shown in FIG.
Is rotated by 90 °, and the curved grooves 48A and 50A are
4A and 14A. Then, the screw rod 38 is pulled to the front side, and the curved grooves 48A and 50A of the pressing tool 24 and the pedestal 2
The heat transfer tubes 14A, 14A are sandwiched between the two curved grooves 28A, 30A as shown in FIG.

Then, when the nut 44 is tightened in this state, the heat transfer tubes 14A, 14A become curved grooves 48A, 50A.
And are guided to the curved grooves 28A and 30A to be corrected to a predetermined axial center position. This nut 44 is tightened with a spanner,
This is performed using a tool such as a torque wrench. Next, the pressing tool 26
After the screw rod 42 is positioned below the vicinity of the welded portion 20 using the elongated hole 40, the screw rod 42 is rotated 90 °,
The curved grooves 48B, 50B are opposed to the heat transfer tubes 14B, 14B. Then, the screw rod 42 is pulled to the front side, and the pressing tool 26
Curved grooves 48B, 50B of the base 22 and curved grooves 28B, 3B of the pedestal 22.
The heat transfer tubes 14B and 14B are sandwiched between the heat transfer tubes 14B and 14B as shown in FIG.

When the nut 46 is tightened in this state, the heat transfer tubes 14B, 14B are bent into curved grooves 48B, 50B.
And are guided to the curved grooves 28B and 30B to be corrected to a predetermined axial center position. As a result, the curved groove 28A and the curved groove 28B of the pedestal 22 and the curved groove 30A and the curved groove 30B
Since the heat transfer tubes 14A and 14B are formed as straight reference grooves, the heat transfer tubes 14A and 14B are centered with the misalignment amount t corrected as shown in FIG. Also,
When the centering jig 10 is used, centering can be performed in all postures from vertical to horizontal.

As described above, in the centering jig 10 of this embodiment, the heat transfer tubes 14 are provided on one side of the furnace wall panels 12A and 12B.
Since the centering work of A and 14B can be performed, the work can be performed by one worker, thereby reducing the number of work steps. In the centering jig 10 of the present embodiment,
Since the pedestal 22 and the pressing tools 24 and 26 are connected by the nuts 44 and 46, it is possible to prevent the pressing tools 24 and 26 from dropping off the pedestal 22 when the centering jig 10 is removed. Therefore, with the centering jig 10 of the present embodiment, highly safe work can be guaranteed.

Further, since the pressing member 26 is guided by the elongated hole 40, it can be positioned at an arbitrary position corresponding to the displacement of the heat transfer tubes 14A and 14B, and can be pressed locally so that the core can be pressed with a small moment force. Can be put out.
Further, since the pressing members 24 and 26 are formed so as to have a small thickness so as to be pressed locally, they can be inserted even in a narrow space, and are small, light and easy to handle.

After the centering is completed, the spaces 32, 34 of the pedestal 22
The welding part 20 is welded by inserting a welding torch by using the method.
This welding condition can be visually confirmed through the spaces 32 and 34. After the welding is completed, the centering jig 10 can be easily removed by reversing the above-described mounting procedure. Therefore, by repeating these steps, all the centering operations of the heat transfer tubes of the furnace wall panel can be performed. it can.

As described above, the centering jig 10 is operated, and after the work for temporarily attaching the groove of the stand pipe is completed, a groove alignment inspection, a main welding and a welded portion inspection are performed, and the welding operation space 18 is set to the blade. To construct a hermetic boiler furnace. Incidentally, as shown in FIG.
When the thrust bearing 52 is provided between the nuts 44 and
6 can be tightened smoothly. As a result, the axial force of the screw rods 38, 42 is improved, so that the pressing tools 24, 26
(See FIG. 1), the heat transfer tubes 14A and 14B can be pressed strongly against the pedestal 22 side. Therefore, the centering accuracy is improved.

FIG. 7 is a perspective view showing the appearance of a centering jig according to a second embodiment of the present invention. The centering jig 60 shown in FIG. 7 is a core of a pair of upper and lower heat transfer tubes 14A and 14B. It is intended to be put out. The pressing tools 62 and 64 of the centering jig 60 have screw rods 66 and 68 formed at one end, and screw portions 70 and 72 formed at the other end. The thickness of the pressing members 62 and 64 is determined by the welding work space 18 (FIG. 1).
).

That is, according to the centering jig 60, the pressing members 62 and 64 are inserted into the welding work space from one side of the furnace wall panel, and are rotated by 90 ° to turn the screw rods 66 and 68.
Nuts 74 and 76, and screw portions 70 and
Tighten the 72 nuts 78,80. Thus, the axis of the heat transfer tube 14A is corrected by the curved groove 62A of the pressing member 62 and the curved groove 84 of the pedestal 82, and the heat transfer tube 14B is formed by the curved groove 64A of the pressing member 64 and the curved groove 86 of the pedestal 82. The center of the heat transfer tubes 14A and 14B can be centered.

FIG. 8 is a perspective view showing the appearance of a centering jig according to a third embodiment of the present invention. The centering jig 90 shown in FIG. Heat transfer tube 14A,
The centering of 14B is performed. Screw rods 98 and 100 inserted into the pedestal 96 are formed on the pressing tools 92 and 94 of the centering jig 90.
The thickness of the plates 2, 94 is determined by the welding work space 18 (see FIG. 1).
It is formed in a dimension that can be inserted into the.

That is, according to the centering jig 90, the pressing members 92 and 94 are inserted into the welding work space from one side of the furnace wall panel, and are rotated by 90 ° so that the screw rods 98 and 10 are rotated.
0 nuts 102 and 104 are tightened. This allows
The axis of the heat transfer tube 14A is corrected by the curved groove 92A of the pressing tool 92 and the curved groove 106 of the pedestal 96, and the pressing tool 94
The heat transfer tube 1 is formed by the curved groove 94A of the base and the curved groove 108 of the base 96.
Since the axis of 4B is corrected, the heat transfer tubes 14A and 14B can be centered.

In the first to third embodiments, the heat transfer tube is centered by the curved reference groove. However, the present invention is not limited to this.
As shown in FIG. 9, V is applied to both the pedestal 110 and the pressing tool 112.
It may be formed by letter-shaped grooves 114 and 116. in this case,
The dimensional error of the outer diameter and cross section of the heat transfer tube is determined by V-shaped grooves 114, 1
16 can be absorbed. Also, as shown in FIG. 10, a V-shaped groove 120 is formed in the pedestal 118,
Even if the second pressing surface 124 is formed flat, it can be centered.

Further, since the heat transfer tube is generally a magnetic material, if the pedestal of the centering jig is made of a magnet, the centering jig can be fixed to the heat transfer tube by magnetic force. Falling can be prevented.

[0028]

As described above, according to the pipe centering jig according to the present invention, the pipe centering work can be performed on one side surface of the pipe panel. Since the first and second pressing tools are connected to the pedestal, it is possible to prevent the pressing tool from being accidentally dropped. This improves safety.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a centering jig and a furnace wall panel according to a first embodiment of the present invention.

FIG. 2 is an external view showing a state in which the centering jig shown in FIG. 1 is mounted on a furnace wall panel.

FIG. 3 is a plan view showing a state in which a pressing tool of a centering jig faces a heat transfer tube.

FIG. 4 is a plan view showing a state where a heat transfer tube is sandwiched between a pedestal of a centering jig and a pressing tool.

FIG. 5 is a side view of the heat transfer tube centered by the centering jig.

FIG. 6 is an explanatory view in which a thrust bearing is attached to a nut to increase the axial force of a screw rod.

FIG. 7 is an external view of a centering jig according to a second embodiment of the present invention.

FIG. 8 is an external view of a centering jig according to a third embodiment of the present invention.

FIG. 9 is an enlarged view of a main part in which V-shaped grooves are formed in both the pedestal and the pressing tool.

FIG. 10 is an enlarged view of a main part in which a V-shaped groove is formed in the pedestal and the pressing tool is a flat plate material.

FIG. 11 is an external view of a boiler furnace.

FIG. 12 is an explanatory view of a main part showing a connection part of a furnace wall panel.

FIG. 13 is a front view of a conventional centering jig.

FIG. 14 is a sectional view of a conventional centering jig.

[Explanation of symbols]

 10, 60, 90: Centering jig 12A, 12B: Furnace wall panel 14A, 14B: Heat transfer tube 16A, 16B: Blade 18: Welding work space 20: Welded part 22, 82, 96: Base 24, 26, 62, 64, 92, 94: pressing tool

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23K 37/053 F16L 39/00

Claims (1)

(57) [Claims] A centering jig for welding a pipe for butt-welding pipe ends of a pipe panel comprising a plurality of pipes having the same diameter connected in parallel at predetermined intervals by a connecting member. A first centering reference groove which is in contact with the peripheral surface of one of the pipes whose pipe ends face each other, and the first core which is in contact with the peripheral surface of the other pipe. A pedestal formed with a centering reference groove and a second centering reference groove formed at a position on a straight line; and a predetermined rotation while being rotatably and slidably connected to the pedestal. At a predetermined interval in the space between the adjacent pipes at a predetermined interval, and is rotated to a predetermined position and slid toward the pedestal side to abut on the one pipe so that the one pipe is A first pressing tool that presses against the first centering reference groove; While being slidably connected, inserted into a space between adjacent pipes at a predetermined rotation position at a predetermined rotation position, rotated to a predetermined position, and slid to the pedestal side. And a second pressing tool that abuts against the other pipe and presses the other pipe against the second centering reference groove. .