JPH1029061A - Automatic tube end welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the workability of the circumferential welding of a tube end part by an automatic tube end welding machine, and to produce a welded product excellent in productivity and economy by attaching an alignment tool provided with an automatic tube end welding machine body in the tube to be welded in one operation. SOLUTION: A shaft hole 27 through a rotary body 3 is provided along the axis of the rotary body 3, on operation shaft 28 is passed through the shaft hole 27, a tip of the operation shaft 28 is brought to a tail end of a retractable shaft 11 provided on an alignment piece 8, and the tail end of the operation shaft 28 is connected to an action shaft of a cylinder 29 which is pivotably and freely supported relative to the rotary body 3. A shaft length adjusting member 33 to adjust the abutting distance to a tail end surface of the retractable shaft 11 is screwed into the tip part of the operation shaft 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, for circumferentially welding the peripheral ends of a large number of liquid flow tubes constituting a heat exchanger to a tube sheet supporting the cold liquid flow tubes. It relates to an automatic pipe end welding machine.

[0002]

2. Description of the Related Art For example, a heat exchanger installed in a nuclear power plant, a thermal power plant, or the like is composed of a number of fluid flow pipes (hereinafter simply referred to as pipes) through which a fluid flows, and a plurality of these pipes. A pipe plate for supporting the pipes in a side-by-side state, and holding the pipe ends of the pipes in a through hole formed in the pipe sheet while holding the pipe ends around the pipe ends. Weld to the tube sheet,
In this configuration, a large number of tubes are supported and fixed to the tube sheet in a parallel state.

Therefore, as a means for circumferentially welding the periphery of the pipe ends of the above-mentioned many pipes to a pipe sheet, an automatic pipe end welding machine as shown in FIG.

[0004] The schematic structure of this automatic pipe end welding machine will be described below. Reference numeral 1 denotes a casing of the welding machine. Inside the casing 1, a rotating body 3 rotated by a motor 2 is rotatably supported via a bearing 4. The rotating body 3 is provided with a rotating cylinder 5 which is expelled from the opening edge of the casing 1 to the outside, and a welding torch 6 is fixed to the rotating cylinder 5 via a bracket 7 to automatically weld a pipe end. The machine body is configured. A centering metal fitting 8 is connected and held inside the tip of the rotary cylinder 5 of the automatic pipe end welding machine body so as to extend on the same axis as the axis of the rotary cylinder 5. The size of the centering metal fitting 8 can correspond to the size (thickness) of the pipe to be welded, and is selected from various types of centering metal fittings prepared in advance.

[0005] As shown in FIG. 4, the centering metal fitting 8 has a rotatable cylinder 5 in which a base end of a support cylinder 10 is rotatably supported via a bearing 9. A retractable shaft 11 is inserted and supported in the axial direction of the cylinder 10 so as to be movable in the axial direction. A movable cone 13 having a tapered surface 12 is fixed to a tip of the retractable shaft 11 by a mounting screw 14.
1 between the tail end and the support cylinder 10.
A coil spring 15 is provided to bias the spring toward the tail end (retraction direction).

A projecting pin 17 is provided at an intermediate position in the longitudinal direction of the retracting shaft so as to penetrate through a long hole 16 formed in the outer surface of the support cylinder 10 and protrude to the outside of the support cylinder 10. . A fixing pin 18 is formed outside the support cylinder 10 so as to approach the protruding pin 17.

Reference numeral 19 denotes a fixed cone having a tapered surface 20. The fixed cone 19 is spaced from the movable cone 13 on the outer periphery of the support cylinder 10. 2
Numeral 1 is a sleeve formed into a tubular shape whose outer diameter can be elastically changed by a plurality of slits 22 formed from both end edges of the tube along the generatrix direction,
Further, the sleeve 21 is provided on the movable side cone 13.
And the fixed side cone 19.

The structure of the main part of the conventional automatic pipe end welding machine has been described above. Next, as shown in FIG. An operation procedure for circumferential welding will be described.

First, in order to align the axis of the rotary cylinder 5 of the automatic pipe end welding machine with the axis of the pipe 24, the centering metal fitting 8 of the automatic pipe end welding machine is inserted into the inside of the pipe 24. In the previous normal state, the outer diameter (R) of the centering metal fitting 8 is widened. That is, the retracting shaft 1 is driven by the elastic force of the coil spring 15.
1 is drawn toward the tail end of the support cylinder 10 so that the distance between the movable cone 13 and the fixed cone 19 is narrowed. As a result, the tapered surfaces 12 and 20 of the cones 13 and 19 are narrowed. As a result, the sleeve 21 is expanded in the diameter direction against the elastic pressure of the sleeve itself. Therefore, unless the outer diameter (R) of the sleeve 21 is reduced, the centering fitting 8 is connected to the pipe 24. Can not be inserted inside.

In order to reduce the outer diameter (R) of the sleeve 21 when inserting the centering member 8 into the tube 24,
The projecting pin 17 and the fixing pin 18 are provided in the slit of the jig 25.
Then, when the jig is rotated to the position 25 'in FIG.
Moves toward the distal end against the elastic force of the coil spring 15. Therefore, the movable-side cone 13 attached to the retractable shaft 11 advances with the retractable shaft 11, and the space between the movable-side cone 13 and the fixed-side cone 19 is widened.

When the space between the movable-side cone 13 and the fixed-side cone 19 is widened, the outer diameter of the sleeve 21 is narrowed by the elastic restoring force of the sleeve 21 itself. Can be easily inserted into After the centering fitting 8 is inserted into the pipe 24 to a predetermined position, the jig 2
5, the retracting shaft 11 is pulled toward the tail end by the elastic force of the coil spring 15, so that the outer diameter of the sleeve 21 is widened, and the outer peripheral surface of the sleeve 21 becomes the inner surface of the tube 24. Contact pressure position.

As a result, the center axis of the centering metal fitting 8 (the rotation axis of the automatic pipe end welding machine) coincides with the axis of the pipe 24, and the centering of the automatic pipe end welding machine is performed.

Next, when the motor 2 is driven while generating an arc from the welding torch 6 to rotate the rotating body 3,
The welding torch 6 rotates at an appropriate speed along the circumference of the end of the pipe 24 in accordance with the rotational force of the rotating body 3, and at this time, if the welding wire is selected from the wire reel 26, the welding torch 16 is rotated. Can be circumferentially welded around the joint between the tube 24 and the tube sheet 23 by the arc generated by the above.

[0014]

As described above, in the conventional automatic pipe end welding machine, the center of the rotating cylinder of the main body of the automatic pipe end welding machine is made to coincide with the center axis of the pipe 24 to be welded. A centering bracket 8 is provided and used as the centering means. Then, in order to center the pipe 24 of the pipe end automatic welding machine body on the pipe 24, the centering metal fittings 8 must be inserted into each of the pipes 24 to be welded. As a means for narrowing the outer diameter of the sleeve 21 at the time of insertion and enabling insertion into the tube, the jig 2
5, the manual operation of moving the retracting shaft 11 in the tail end direction each time, that is, the manual operation of the centering fitting 8 was required.

Accordingly, performing the manual operation of the centering metal fitting 8 for each pipe 24 to be welded is inferior in workability at the time of pipe end welding, and the rotation axis of the automatic pipe end welding machine is changed to the axis center of the pipe 24. However, there is a problem that it takes a lot of time to perform the work to match the situation. In order to manufacture a large heat exchanger to be installed in a power plant, several hundred heat exchangers per unit must be used.
Since a large number of thousands of pipes have to be fixed to the tube sheet by welding, it is necessary to manually insert the centering metal fitting 8 into each of such a large number of pipes. Is very labor-intensive, lacks productivity and economical efficiency of welding products, and has been required to improve those disadvantages.

SUMMARY OF THE INVENTION The present invention has been made in order to meet such a demand, and enables the centering metal fitting provided in the pipe end automatic welding machine main body to be inserted into the pipe to be welded by one-touch operation. With the aim of improving the workability of girth welding of the pipe end by the automatic pipe end welding machine, and by extension, providing a pipe end automatic welding machine capable of producing welding products excellent in productivity and economy. Is what you do.

[0017]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a rotating body which is rotated by a motor, and which is located on the same axis as the rotating axis of the rotating body, and A rotating cylinder that is integral with the body, a centering bracket that is coupled and supported by the rotating cylinder, and that is positioned so that the axis is aligned with the axis of the rotating cylinder; and a bracket outside the rotating cylinder. In a pipe end automatic welding machine having a welding torch held through, a shaft hole is provided to penetrate the rotating body along the rotation axis of the rotating body, and an operation shaft is penetrated in the shaft hole. The tip of the operating shaft is made to reach the tail end of the retracting shaft provided on the centering bracket, and the tail end of the operating shaft is moved to the operating shaft of the cylinder which is freely supported with respect to the rotating body. It is characterized by being a connected pipe end automatic welding machine To have.

According to a second aspect of the present invention, in addition to the first aspect, a pipe end automatic welding in which a shaft length adjusting member for adjusting a contact distance with a tail end surface of a retractable shaft is screwed to a distal end portion of the operating shaft. It is characterized by being a machine.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.
And FIG. 2, the present invention has a feature in the operation mechanism of the centering bracket, and other mechanisms are the same as those of the conventional example. The same reference numerals are used as those used, and the description of the same structural parts is omitted.

1 and 2, a rotating body 3 rotatably supported in a casing 1 via a bearing 4 has a rotating body 3 formed along its axis of rotation and both end faces of the rotating body 3. A shaft hole 27 penetrating therethrough is formed. Accordingly, the rotational force transmission mechanism, the power supply mechanism, the gas supply path, and the like (not shown) incorporated in the inside of the rotating body 3 avoid the shaft hole 27.

An operating shaft 28 is passed through the shaft hole 27. The tip of the operating shaft 28 (the left end in the drawing).
Extends to the inside of the rotary cylinder 5, and its tip is close to the tail end of the pull-in shaft 11 constituting the centering fitting 8. The tail end of the operation shaft 28 is the air cylinder 2
9 is connected to the operating shaft 30 of the air cylinder 29.
The air cylinder 29 is rotatably supported via a bearing 32 on a mounting base 31 provided integrally with the rotating body 3. Therefore, this air cylinder 29 is
Even if 1 rotates around the shaft hole 27, the air cylinder 29
Is connected to this air cylinder 29 in order to be kept in a fixed position without being rotated. The air supply hose (not shown) does not twist.

A shaft length adjusting member 33 is screwed to the distal end of the operating shaft 28. The shaft length adjusting member 33 is positioned by the fastening force of the lock nut 34, and The entire length of the operation shaft 28 including the shaft length adjusting member can be adjusted so that the tip is located closer to the tail end of the retractable shaft 11.

Reference numeral 35 denotes a hose connection port provided in the air cylinder 29 for supplying pressurized air, and reference numeral 39 denotes an operation switch for operating an electromagnetic valve for opening and closing the air passage. , The pressurized air supplied from the hose connection port 35 into the air cylinder 29 is supplied into the cylinder, and as a result, the operation shaft 28 protrudes toward the distal end.

Reference numeral 36 denotes a wire feeder attached to the mounting base 31 by mounting screws 38. The wire (not shown) wound on the reel 37 by the action of the wire feeder is provided. It is supplied sequentially to the weld.

The above is the embodiment of the automatic pipe welding machine according to the present invention. Next, the operation will be described. The automatic pipe end welding machine having the above-mentioned structure shown in FIG. At the time of circumferential welding of the peripheral edge, first, the centering metal fitting 8 of the automatic pipe end welding machine is inserted into the inside of the pipe 24 so that the rotation axis of the automatic pipe end welding machine coincides with the axis of the pipe 24. However, as described above, since the outer diameter of the sleeve 21 is expanded by the elastic force of the coil spring 15 in the centering metal member 8 before being inserted into the tube 24, the centering metal member 8 is Cannot be inserted into

Then, when the operation switch 39 of the air cylinder 29 is operated by one-touch operation, pressurized air is supplied into the cylinder 29, and the operation shaft 28 is pushed out toward the tip. When the operating shaft 28 is pushed out, the retracting shaft 11 of the centering bracket 8 is pushed toward the distal end against the elastic force of the coil spring 15. If the retracting shaft 11 moves in the distal direction, the space between the movable cone 13 and the fixed cone 19 is widened in the same manner as in the description of the conventional example, and the sleeve 21 has an elastic restoring force held by the sleeve. As a result, the outer diameter is narrowed, so that the centering fitting 8 can be inserted into the tube 24. If the pressing force of the operation switch 39 is released after the centering metal fitting 8 is inserted into the pipe 24 to a predetermined position and the supply of pressure to the air cylinder 29 is stopped, the retracting shaft 11 is tailed by the elastic force of the coil spring 15. As a result, the outer diameter of the sleeve 21 is increased, and the outer peripheral surface of the sleeve 21 is elastically pressed against the inner surface of the tube 24.

As a result, the center axis of the centering metal fitting 8 (the rotation axis of the automatic pipe end welding machine) is aligned with the axis of the pipe 24, and the centering positioning of the automatic pipe end welding machine is completed.

When the centering metal fitting 8 is inserted and positioned in the pipe 24, the rotation axis of the automatic pipe end welding machine is changed to the pipe 24.
When the arc is generated while driving the motor 2 while rotating the welding torch 6 while maintaining the alignment of the axis by the centering bracket 8, the rotation of the welding torch 6 can be achieved. Accordingly, the periphery of the end of the tube 24 and the tube sheet 2
3 can be electrically welded.

After the welding of the tube 24 and the tube plate 23 is completed, the operation switch 39 is pushed, and the air cylinder 29 is operated again to move the retracting shaft 11 of the centering metal fitting 8 toward the front end thereof. Since the outer diameter of the sleeve 21 in the centering member 8 is narrowed, the centering member 8 is connected to the tube 24 in this state.
It can be pulled out from the inside, and the drawn out centering metal fitting 8 can be inserted into the inside of the tube 24 to be welded next, and the centering in preparation for welding the next tube 24 can be performed.

[0030]

As is apparent from the above description, according to the automatic pipe end welding machine of the present invention, the retracting shaft 11 of the centering metal fitting 8 provided in the automatic pipe end welding machine is connected to the air cylinder 29. Can be operated. Thus, each operation of inserting the centering metal fitting 8 into the tube 24 and pulling the centering metal fitting inserted into the tube 24 out of the tube is a one-touch operation for operating the air cylinder 29, that is, Since the operation can be performed by a simple operation only by pushing the operation switch 39, the operation for aligning the axis of the pipe end automatic welding machine with the axis of the pipe 24 to be welded is very easily and surely performed. I can do it.

Therefore, a large number of pipes 24 of several hundreds or thousands
The effect that workability for welding the periphery of the pipe to the tube sheet 23 is significantly improved is obtained.

In the present invention, since the shaft length adjusting member 33 for adjusting the total length of the operation shaft is provided at the tip of the operation shaft, the centering metal fitting 8 provided in the automatic pipe end welding machine is pulled in. Even if there is a dimensional variation in the length of the shaft 11, the tip of the operating shaft 28 can be accurately brought into contact with the tail end of the retracting shaft 11. Correspondingly, even if the centering brackets 8 of various sizes are exchanged, the effect that the various centering brackets 8 can be reliably operated can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of an automatic pipe end welding machine according to the present invention.

FIG. 2 is an explanatory view showing an operation mechanism of a centering fitting according to the present invention.

FIG. 3 is an explanatory view showing a conventional pipe end automatic welding machine.

FIG. 4 is a cross-sectional view showing the entire structure of the centering fitting.

[Description of Signs] 1 ... Casing 2 ... Motor 3 ... Rotating body 4 ... Bearing 5 ... Rotating cylinder 6 ... Welding torch 7 ... Bracket 8 ... Centering bracket 9 ... Bearing 10 ... Support cylinder 11 ... Retraction shaft 12 ... Tapered surface 13 ... Movable cone 14 ... Mounting screw 15 ... Coil spring 16 ... Long hole 17 ... Protruding pin 18 ... Fixing pin 19 ... Fixed cone 20 ... Tapered surface 21 ... Sleeve 22 ... Slit 23 ... Tube plate 24 ... Tube 25 ... Jig 26 ... wire reel 27 ... shaft hole 28 ... operating shaft 29 ... air cylinder 30 ... operating shaft 31 ... mounting base 32 ... bearing 33 ... shaft length adjusting member 34 ... lock nut 35 ... hose connection port 36 ... wire feeding device 37 ... Reel 38: Mounting screw 39: Operation switch

Claims (2)

[Claims] A rotating body (3) rotated by a motor (2), and a rotating cylinder positioned on the same axis as the rotating axis of the rotating body (3) and integral with the rotating body (3). (5) and
A centering metal fitting (8) which is connected and supported by the rotating cylinder (5) and whose axis is positioned so as to coincide with the axis of the rotating cylinder (5); In an automatic pipe end welding machine having a welding torch (6) held via a bracket (7), a shaft hole penetrating through the rotary body (3) along the rotary axis of the rotary body (3). (2
7), an operating shaft (28) is passed through the shaft hole (27), and the tip of the operating shaft (28) is connected to the retracting shaft (11) provided on the centering metal fitting (8). And the tail end of the operating shaft (28) is connected to the operating shaft (30) of a cylinder (29) freely supported by the rotating body (3). Features Automatic pipe end welding machine. 2. A shaft length adjusting member (33) for adjusting a contact distance between a tip end of an operation shaft (28) and a tail end surface of a drawing shaft (11) in the automatic pipe end welding machine according to claim 1. Pipe end automatic welding machine characterized by screwing in).