JP2001150132A - Automatic seal-welding device for tube end - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic seal-welding device for tube ends with which the workability of circumference welding of tube ends with the automatic seal- welding machine for the tube ends is raised and, in its turn, welded products excellent in productivity and economy are produced by enabling a centering mechanism part which is made to be possessed by the main body of the automatic welding machine for the tube ends inserting into the inside of a tube to be welded and breaking away from the tube in one operation. SOLUTION: In the automatic seal-welding device for tube ends, which has a rotary cylinder rotated with a motor, a retracting shaft which is situated on the same axial center as the axial center of rotation of this rotary cylinder and inserted and held slidably in the direction of the axial center to the rotary cylinder, a part for catching a material to be centered provided with a cone with which the outside diameter of a sleeve is expanded and a welding torch which is held on the outside of the rotary cylinder through a bracket, a spring for always energizing the retracting shaft in the direction of the rear end and an operating lever for moving the retracting shaft in the direction of the tip against the elasticity of the spring are provided at the rear end of the retracting shaft.

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. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe end automatic seal welding apparatus, and more particularly to a pipe end automatic seal welding apparatus capable of accurately and quickly positioning the pipe end automatic seal welding apparatus to a position to be sealed.

[0002]

2. Description of the Related Art For example, a heat exchanger used in a nuclear power plant, a thermal power plant, or the like is composed of a number of liquid flow pipes (hereinafter, simply referred to as pipes) through which a liquid flows.
And these pipes are inserted into a plurality of through holes formed in a tube support plate (hereinafter simply referred to as a tube plate), and an end face of each tube is sealed around each through hole of the tube plate. Then, there is a configuration in which each tube is supported and fixed to a tube sheet.

In order to manufacture a heat exchanger having the above structure, the ends of a large number of tubes are supported by being passed through through holes formed in a tube sheet, and then each of the tube ends and each through hole are supported. An automatic pipe end seal welding device is used as a welding means for seal-welding the periphery of a pipe.

[0004] A schematic structure of this known pipe end automatic seal welding apparatus will be described with reference to FIG. 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 projecting 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 seal a pipe end. The machine body is configured. A centering mechanism 8 is connected and held inside the tip of the rotary cylinder 5 of the pipe end automatic seal welding machine body so as to extend on the same axis as the axis of the rotary cylinder 5. .

As shown in FIG. 7, a rotatable base end of a support cylinder 10 is rotatably supported inside the rotary cylinder 5 via a bearing 9. ,
The retractable shaft 11 is inserted and supported so as to be movable in the axial direction. A movable-side cone 13 having a tapered surface 12 is fixed to a tip of the retractable shaft 11 by a mounting screw 14, and a retractable shaft is provided between a tail end of the retractable shaft 11 and the support cylinder 10. A coil spring 15 that urges 11 toward the tail end (retracting direction) is interposed.

A projecting pin 17 is provided at an intermediate position in the longitudinal direction of the retracting shaft so as to protrude to the outside of the support cylinder 10 through an elongated hole 16 formed in the outer surface of the support cylinder 10. I have. 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.

Reference numeral 23 denotes a rotary handle for moving the retractable shaft 11 in the axial direction. The rotary handle 23 is connected to the retractable shaft 11 and is movable in the casing 1 in the axial direction. It is screwed to the screw member 24.

Next, each pipe 2 held in a through hole of the tube sheet 26 by the conventional pipe end automatic seal welding apparatus having the above-described configuration.
An operation procedure for circumferentially welding the periphery of the through end of No. 7 and the periphery of the through hole of the tube sheet 26 will be described.

First, in order to align the axis of the rotary cylinder 5 with the axis of the pipe 27 by this automatic pipe end seal welding machine, the centering mechanism 8 of the automatic pipe end seal welding machine is inserted into the inside of the pipe 27. I do.

At this time, the outer diameter of the sleeve 21 indicated by the symbol R in the figure is widened before the insertion. This is because the retraction shaft 11 is drawn toward the tail end of the support cylinder 10 by the elastic force of the coil spring 15, so that the distance between the movable-side cone 13 and the fixed-side cone 19 is reduced. Since the sleeve 21 is expanded in the diameter direction against the elastic force of the sleeve 21 due to the influence of the tapered surfaces 12 and 20 of 13 and 19, if the outer diameter R by the sleeve 21 is not reduced, the centering mechanism is left as it is. The structure is such that the part 8 cannot be inserted into the tube 27.

When the centering mechanism 8 is inserted into the tube 27, the outer diameter R of the sleeve 21 is reduced.
Rotating handle 2 attached to the rearmost part of retract shaft 11
By manually rotating 3, for example, to the left,
For example, a moving screw member 24 which is integrally formed with the retraction shaft 11 and has a left-hand thread is moved in the distal direction.

By the operation of moving the moving screw member 24,
The retracting shaft 11 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 distance between the movable-side cone 13 and the retractable shaft 11 is increased.

The movable side cone 13 and the retracting shaft 11
Is increased, the sleeve 21 becomes
Since the outer diameter R is reduced by its own elastic restoring force, the centering mechanism 8 can be easily inserted into the tube 27.

After the centering mechanism 8 has been inserted to a predetermined position in the tube 27 in this manner, the revolving handle 23 is manually rotated in the future, for example, clockwise, so that the retracting shaft 11 It is pulled toward the tail end by the elastic force, so that the sleeve 21
13, the outer diameter R is widened again, and the outer peripheral surface of the sleeve 21 is brought into contact with the inner surface of the tube 27 by pressure.

As a result, the center axis of the centering mechanism 8, ie, the axis of rotation of the pipe end automatic seal welding machine coincides with the axis of the pipe 27, and the centering positioning of the pipe end automatic seal welding machine is performed. Has been completed.

Thereafter, when the rotating body 3 is rotated at a constant speed by driving the motor 2 while generating an arc from the welding torch 6, the welding torch 6 is moved to the end of the pipe 27 according to the rotating force of the rotating body 3. It rotates at an appropriate speed along the periphery of the rim, and the arc generated by the welding torch 6 causes the pipe 27 and
Can be welded circumferentially around the joint.

[0018]

The above-mentioned conventional pipe end automatic seal welding apparatus is provided with a centering mechanism section 8 for centering the pipe end automatic seal welding apparatus with respect to each pipe 27. The centering mechanism 8
At the time of insertion into the tube 27, as a means for narrowing the outer diameter of the sleeve 21 to enable insertion into the tube 27, the revolving handle 23 for turning operation is used to tail the retraction shaft 11 each time. A manual operation by the rotation operation handle 23 of the centering mechanism 8 for centering to move in the end direction was required.

When the rotating operation handle 23 is manually rotated, it is difficult for the rotating operation handle 23 to interfere with the welding edge of the pipe end, and it is particularly difficult to perform the rotating operation in a narrow work space in the water chamber. There were also problems such as.

Therefore, performing the manual rotation operation of the rotation operation handle for each pipe 27 to be welded is as follows.
Extremely deteriorates workability during automatic pipe end seal welding. In particular, as in the case of manufacturing a large heat exchanger installed in a power plant, hundreds to thousands of tubes 27 per heat exchanger are fixed to the tube sheet 26 by welding. In this case, it is necessary to repeat the forward rotation and the reverse rotation of the rotating operation handle as described above for each one of them one by one to perform the manual operation, which increases productivity and economy as a welding product. Significantly inhibited.

The present invention has been made in view of the above circumstances, and the centering mechanism can be inserted into the pipe to be welded by a one-touch operation using a lever. Automatic pipe end seal welding that simplifies the work required for inserting the mechanism inside the pipe, improves the workability of circumferential welding of the pipe end, and enables high productivity and economical welding of excellent quality weld products. The purpose is to provide a machine.

[0022]

According to a first aspect of the present invention, there is provided a rotary cylinder rotated by a motor, the rotary cylinder being located on the same axis as the rotational axis of the rotary cylinder, and Centering provided with a retractable shaft inserted and held slidably in the direction of its axis with respect to the rotary cylinder, and a cone provided at the distal end of the retractable shaft and capable of expanding the outer diameter of the sleeve. In a pipe end automatic seal welding apparatus having a mechanism and a welding torch held via a bracket on the outside of a rotary cylinder, the retractable shaft is always urged toward the rear end thereof at the rear end of the retractable shaft. The present invention is characterized in that it is an automatic pipe end seal welding apparatus provided with a spring and an operation lever for pushing a retracting shaft toward a tip end thereof against the elasticity of the spring.

By adopting such a structure, the retractable shaft is conventionally reciprocated in the front-rear direction by rotating the rotary handle, whereas the retractable shaft is always attached to the rear end direction as in the present invention. By providing a biasing spring and an operation lever for pushing the retracting shaft in the distal direction, the axial reciprocating operation of the retracting shaft can be performed quickly with one touch.

According to a second aspect of the present invention, the first aspect is provided.
Wherein the operation lever is a gun lever type automatic pipe end seal welding apparatus.

With this configuration, the one-touch operation of the operation lever can be performed more smoothly, quickly, and easily, and the work of inserting and detaching the centering mechanism into and from the pipe can be performed more quickly.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic pipe end seal welding apparatus according to the present invention will be described below with reference to FIGS. 1 to 5. The operation of the automatic pipe end seal welding apparatus according to the present invention will be described. Except for the lever structure, the configuration is basically the same as the configuration shown on the conventional side, and therefore the same portions are denoted by the same reference numerals and description of the same portions will be omitted.

1 to 4, a cylindrical bearing 30 is provided along a central axis inside the casing 1, and the drawing shaft 11 is inserted into a shaft hole 31 of the bearing 30, It is slidably inserted in the direction of the center.

The rear end of the retractable shaft 11 is inserted and supported in a shaft hole 34 of a lever shaft support member 33 screwed to the casing 1 by a mounting screw 32. Each locking pin 3 is located at the rear end side symmetrical position of the insertion shaft 11 that is inserted and supported.
5 are protrudingly provided.

A stepped portion 36 having a large outer diameter is formed around the rear end of the retractable shaft 11. The stepped portion 36 and the stepped portion formed around the inside of the shaft hole 31 are formed. A spring 38 is interposed between the spring 37 and the spring 38, and the elasticity of the spring 38 always pulls the retracting shaft 11 in the rear end direction A.

A support shaft 39 is provided on the lever shaft support member 33.
The operating lever 40 is pivotally supported via the lever, and the above-mentioned locking pin 35 is engaged with the inside of a rub 41 formed at one end of the operating lever 40. Therefore, this operation lever 4
By rotating the shaft 0 in the arrow direction B shown in FIG. 3 with the support shaft 39 as a fulcrum, the retracting shaft 11 can be pushed in the direction opposite to the arrow direction (A) against the elastic force of the spring 38. it can.

The distal end of the retractable shaft 11 has a movable side cone 13 constituting a centering mechanism 8 similar to that described in the conventional example of FIG.

In the above configuration, for example, as shown in FIG. 1, when circumferentially welding the peripheral edges of the tube sheet 26 and the tube 27, the centering mechanism 8 is first inserted into the tube 27. ,
The axis of rotation of the pipe end automatic seal welding device is made to coincide with the axis of the pipe 27. At this time, the elastic force of the spring 38 is applied to the centering mechanism 8 before it is inserted into the pipe 27. Since the outer diameter of the sleeve 21 is widened due to the positional relationship between the retractable shaft 11 and the movable-side cone 13 which are drawn rearward, the centering mechanism 8 cannot be inserted into the pipe 27 as it is. .

When the operating lever 40 is operated one-touch in the direction of the arrow (B) in FIGS.
Is pushed toward the distal end thereof against the elastic force of the spring 38, and the pressing force of the movable cone 13 on the sleeve 21 is released. Therefore, the outer diameter of the sleeve 21 is narrowed by its own elastic restoring force, and the centering mechanism 8 can be inserted into the tube 27.

When the centering mechanism 8 is inserted into a predetermined position in the tube 27, the operation lever 40 is moved in the arrow direction (B).
When the turning force is released, the retracting shaft 11 is restored in the direction of the arrow (A) by the elastic force of the spring 38. As a result, the outer diameter of the sleeve 21 is increased, and the outer surface of the sleeve 21 is
7 is pressed against the inner peripheral surface of the inner peripheral surface 7 in a resilient manner.

As a result, the center axis of the centering mechanism 8, that is, the axis of rotation of the pipe-end automatic seal welding machine coincides with the axis of the pipe 27, and the centering positioning of the pipe-end automatic seal welding machine is performed. Has been completed.

Thus, if the motor 2 is driven to rotate the rotating body 3 at a constant speed while generating an arc from the welding torch 6 while maintaining the state of positioning by the centering mechanism section 8, The welding torch 6 rotates at an appropriate speed along the periphery of the end of the tube 27 according to the rotational force of the rotating body 3, and the arc generated by the welding torch 6 causes the tube 2 to rotate.
The periphery of the joint between the pipe 7 and the tube sheet 26 can be welded circumferentially.

After the welding of the tube 27 and the tube sheet 26 is completed,
When the operating lever 40 is pushed again in the direction of the arrow (B) to move the retracting shaft 11 of the centering mechanism 8 toward the distal end thereof, the outer diameter of the sleeve 21 in the centering mechanism 8 is reduced. With this, the sleeve 21 can be pulled out of the tube 27.

The same operation as described above is performed to insert the extracted centering mechanism 8 into the pipe 27 to be welded next, and thereafter, the above-described series of operations is repeatedly performed, whereby a number of operations are performed. Welding can be processed efficiently.

As described above, the insertion and removal of the centering mechanism 8 into and from the tube 27 can be easily realized only by one-touch operation of the operation lever 40. Therefore, the centering operation for aligning the rotation axis of the pipe end automatic seal welding machine with the axis of the pipe 27 to be welded can be performed extremely easily and reliably, and particularly, a large amount of welding work can be performed. In the case where the operation has to be performed continuously, the workability can be remarkably improved.

In the embodiment shown in FIGS. 1 to 3,
Since the operation lever 40 is directed upward, for example, when there is an obstacle near the upper portion of the operation lever 40 and it is difficult to rotate the operation lever 40, the mounting screw 32 is removed. Since the direction of the lever shaft support member 33 can be changed, for example, by 90 degrees and 180 degrees, the operation lever 40 can be operated without being adversely affected by workplace conditions.

FIG. 5 shows another embodiment of the present invention. In this embodiment, the gun grip 42 is attached to the rear end of the casing 1 and the retraction shaft 11 is attached to the casing 1 in the same manner as in the above embodiment. The gun valley 43 formed by pin connection is pivotally supported on the gun grip 42. Therefore, according to this embodiment, since the gun lever 43 can be pushed in the axial direction of the retracting shaft 11 with only the index finger of the operator holding the pipe end automatic seal welding device, It is possible to expect much more effective operability and quicker operation than the turning operability by the operation lever 40 of FIG.

[0042]

As described above, according to the automatic pipe end seal welding apparatus of the first aspect of the present invention, the operation lever is tilted to expand or narrow the outer diameter of the sleeve of the centering mechanism. The centering mechanism is inserted into the pipe to be welded, and the axis of the pipe end automatic seal welding device is aligned with the axis of the pipe to be welded. The matching operation and the drawing operation from the inside of the pipe can be performed by one-touch operation.

According to the pipe end automatic seal welding apparatus according to the second aspect of the present invention, the gun lever for expanding or narrowing the outer diameter of the sleeve can be operated with only the index finger. Excellent workability and quickness can be expected.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of a pipe end automatic seal welding apparatus according to the present invention.

FIG. 2 is a rear view showing an embodiment of an automatic pipe end seal welding apparatus according to the present invention.

FIG. 3 is an enlarged explanatory view of a main part showing an embodiment of a pipe end automatic seal welding apparatus according to the present invention.

FIG. 4 is a side view of a centering portion showing an embodiment of a pipe end automatic seal welding apparatus according to the present invention.

FIG. 5 is an explanatory side view showing another embodiment of the automatic pipe end seal welding apparatus according to the present invention.

FIG. 6 is an explanatory side view showing a conventional pipe end automatic seal welding apparatus.

FIG. 7 is an explanatory view showing a centering mechanism of a conventional pipe end automatic seal welding apparatus.

[Explanation of symbols]

(30)--Bearing (31)---Shaft hole (32)-
−−Mounting screw (33) −−− Lever shaft support member (34) −
−−Shaft hole (35) −−− Locking pin (36) −
−−Stepped part (37) −−− Stepped part (38) −
−−Spring (39) −−− Spindle (40) −
−−Operation lever (41) −−− Split

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hirotaka Suga 5-8-6 Ryoke, Kawaguchi-shi, Saitama F-term in Dai-ichi Mechatech Co., Ltd. 4E081 EA12 EA33 YS01

Claims (2)

[Claims] 1. A rotary cylinder which is rotated by a motor, and a retraction which is located on the same axis as the rotary axis of the rotary cylinder and is slidably inserted into and held by the rotary cylinder in the axial direction. A shaft, a centering mechanism provided at a distal end of the retractable shaft and having a cone capable of expanding the outer diameter of the sleeve, and a welding torch held via a bracket outside the rotary cylinder. A spring which constantly urges the retractable shaft toward the rear end thereof, and which pushes the retractable shaft toward the distal end thereof against the elasticity of the spring at the rear end of the retractable shaft. An automatic pipe end seal welding device comprising an operating lever for moving. 2. The automatic pipe end seal welding apparatus according to claim 1, wherein the operation lever is a gun lever type.