JP2003088956A - Method and device for automatically seal-welding pipe end parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for automatically seal-welding pipe end parts with which the automatic seal-welding device for pipe end parts is miniaturized and lightened and also, the workability of the welding device is improved and the precision in a welding position and the welded quality can be improved. SOLUTION: A casing shape in the automatic seal-welding device for pipe end parts is compacted as almost lateral cylindrical shape and the material of this casing is made of resin to lighten this device. Further, this device is used by arranging a displacing sensor for detecting distance between this automatic seal-welding device for pipe end parts and a position to be welded and/or a temperature sensor for detecting the heating temperature of the material to be welded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, circumferential welding of the peripheral edges of the ends of a large number of liquid flow pipes constituting a heat exchanger to a tube plate for supporting the liquid flow pipes. A pipe end automatic seal welding method and device, in particular, the pipe end automatic seal welding device is reduced in size and weight to improve the workability of the welding work performed by holding the welding device by hand, and to improve the accuracy of the welding position and the welding quality. The present invention relates to a pipe end automatic seal welding method and apparatus that enables the above.

[0002]

2. Description of the Related Art For example, a heat exchanger used as a facility in a nuclear power plant, a thermal power plant, etc. has a large number of liquid flow pipes (hereinafter simply referred to as pipes) for circulating a liquid for heat exchange. And a tube support plate (hereinafter, simply referred to as a tube plate) for separately supporting these many tubes and forming a heat exchange chamber. In order to connect with, the tube end is inserted into each of a large number of through holes preliminarily bored in the tube sheet, and the outer periphery of the end of each tube and the peripheral edge of the through hole of the tube sheet are sealed and welded. As a result, the tube sheet and a large number of tube ends are integrated.

A pipe end automatic seal welding device is used as a means for welding the above-mentioned many pipe ends to the peripheral edge of each through hole provided in the pipe sheet.

A schematic structure of a known pipe end automatic seal welding device will be described with reference to FIG. 3. Reference numeral 1 is a pipe end automatic seal welding device having a device casing 3 having a handgrip portion 2 at a lower portion thereof. Therefore, a motor (not shown) is installed inside the casing 3 of the pipe end automatic seal welding apparatus 1, and the rotary cylinder 4 rotated by the motor is disposed in front of the casing 3.

A welding torch 6 is fixed to the outside of the rotary cylinder 4 via a bracket 5. Further, the tube-expanding type centering metal fitting 7 is spent from the tip of the rotary cylinder 4, and the structure of the tube-expanding type centering metal fitting 7 is provided with a plurality of slits 8 formed along the generatrix direction. The pipe expanding member 9 and an operating shaft 10 for axially displacing a cone member (taper member) provided inside the pipe expanding member 9 are provided, and the operating shaft 10 moves in the axial direction. The outer diameter of the pipe member 9 is elastically changed by the displacement of the cone member.

In order to perform seal welding between the end edge portion of the pipe A shown in FIG. 3 and the through hole edge C formed in advance on the tube sheet B using the above-mentioned pipe end automatic seal welding apparatus, first, After inserting the tube-expanding type centering fitting 7 provided in the tube end automatic seal welding apparatus 1 into the tube A, a cylinder (not shown) is operated to axially displace the operating shaft 10, resulting in the tube expanding member. The outer diameter of the pipe expanding member 9 is expanded to bring the outer peripheral surface of the pipe expanding member 9 into pressure contact with the inner peripheral surface of the pipe A, and the centering of the pipe end automatic seal welding device is performed, that is, the pipe end automatic seal welding device is positioned with respect to the pipe A and welded. The swing of the torch 6 is restricted.

Then, voltage is applied to the tungsten electrode 11 of the welding torch 6 to start TIG welding. At the same time as the TIG welding is started, the rotary cylinder 4 is rotationally driven so that the welding torch 6 and the tungsten electrode 11 are connected to the pipe A. And tube sheet B
By rotating along the peripheral edge of the welded portion between and, the seal welding between the periphery of the end edge of the pipe A and the pipe sheet B is performed.

[0008]

Thus, a single pipe A is provided.
When the seal welding between the tube sheet and the tube sheet B is completed, the pipe-expansion centering fitting 7 is replaced in the next tube A, and the seal welding of the next tube edge and the tube sheet is sequentially repeated by the same operation as above. Although it is returned, the entire length of the heat exchanger used in power plants, etc. is large because it is necessary to seal and weld tens of thousands of tubes A per heat exchanger. It takes a lot of labor and time to assemble the above-mentioned large-sized heat exchanger using the conventional large-sized and heavy-weight automatic pipe-end seal welding apparatus having a size of 520 mm, an overall width of 100 mm, and a weight of 8.5 kg. It lacked workability.

Therefore, when performing seal welding of a large number of pipes A and pipe sheets B using the above-mentioned conventional pipe end automatic seal welding device, preparatory work is required to improve the welding workability, As a preparatory work, for example, as shown in FIG. 3, a slide rail for moving the pipe end automatic seal welding apparatus 1 in the front-rear and left-right directions while suspending it on the upper wall 12 of the heat exchanger configuration chamber (water chamber). A mechanism 13 is further provided, and further a spring balancer 14 for reducing the weight load of the pipe end automatic seal welding apparatus 11 is provided, and the pipe end automatic seal welding device is hung on the slide rail mechanism via the spring balancer 14. I have it. In this case, the rail mechanism and the balancer interfere with the welding part and hinder the welding work, and the preparation work for mounting the rail mechanism and the balancer, etc., requires a lot of labor and cost, and the pipe end seal welding work is performed. There was a problem that the efficiency was low.

Further, by using the above-mentioned spring balancer, it is possible to balance the weight of the pipe end automatic seal welding device, but in this case, the positional stability of the pipe end automatic seal welding device is poor and the pipe end automatic seal is poor. There is also a problem in that the welding apparatus is apt to be swung, which causes the weld bead size to be non-uniform, which easily causes welding defects.

For example, titanium material is used as the material of the tube A and the tube sheet B which compose the heat exchanger. When welding the titanium material, the welding atmosphere temperature is 3%.
When the temperature is higher than 00 ° C, the characteristics of the titanium material change and the material becomes brittle, so it is necessary to control the welding atmosphere temperature. Conventionally, however, the welding atmosphere temperature during the welding operation is required. Since it is difficult to detect and manage the object, the object to be welded may be heated to a high temperature of, for example, 300 ° C. or more for a long time, resulting in embrittlement of the object to be welded. .

As described above, in the seal welding work using the conventional large-scale automatic pipe-end seal welding apparatus, the automatic pipe-end seal welding apparatus is large and weighs up to about 10 kg. The seal welding work for seal-welding, for example, tens of thousands of tube ends around the exchanger to the tube sheet has the above-mentioned various problems, and a pipe-end automatic seal welding method and a method capable of solving those problems. Equipment development is required.

The present invention has been made in order to meet such a requirement, and at the time of pipe end welding work in which the pipe end automatic seal welding device is gripped and used, the distance between the welding surface of the pipe end automatic seal welding device and the welding device is set. A pipe end automatic seal welding device that can constantly detect and manually control so that the distance between the seal welding position and the welding electrode is constant to improve the uniformity of welding quality and its welding accuracy. The primary purpose is provision.

Further, according to the present invention, during welding operation, the ambient temperature of the welded portion is constantly detected to prevent the embrittlement of the welded article due to abnormal heating of the welded article. A second object is to provide an automatic seal welding device.

Further, in the present invention, the pipe end automatic seal welding apparatus is lightened and miniaturized so that a welding operator can grasp and operate it with one hand, thereby performing welding by hand holding the pipe end automatic seal welding apparatus to an object to be welded. It is easy to allow the work to be performed, and it is also easy to manually adjust the position and inclination of the pipe end automatic seal welding device during welding work, thereby facilitating the welding work using the pipe end automatic seal welding device. A third object is to provide a pipe end automatic seal welding method capable of enhancing ease and economy.

[0016]

In order to achieve the above-mentioned first object, according to claim 1 of the present invention, a rotating cylinder rotated by a motor provided in a casing of a welding apparatus and an outside of the rotating cylinder are provided. In a pipe end automatic seal welding apparatus comprising a welding head held via a bracket and a pipe expansion centering mechanism located in front of the welding head and concentric with the rotary cylinder, the pipe end automatic seal is provided. A pipe in which a displacement sensor for detecting the distance between the welding device and the position to be welded is fixed to the eccentric position of the rotary cylinder, and an indicator for displaying the condition of the distance change detected by the displacement sensor is provided. It is characterized by an automatic end seal welding device.

In order to achieve the above-mentioned second object, according to a second aspect of the present invention, a rotary cylinder rotated by a motor provided in a casing of a welding device, and a rotary cylinder held outside the rotary cylinder via a bracket. A welding head, and a pipe end automatic seal welding device which is located in front of the welding head and is concentric with the rotary cylinder, wherein an object to be welded is provided outside the rotary cylinder. The pipe end automatic seal welding device is characterized in that it has a temperature sensor for detecting the heating temperature of 1) and is further equipped with a temperature indicator for displaying the detected temperature detected by the temperature sensor.

In order to achieve both the first and second objects, the third aspect of the present invention is the pipe end automatic seal welding apparatus according to the first aspect, and the temperature sensor according to the second aspect. It is characterized in that it is a pipe end automatic seal welding device equipped with a temperature indicator.

In order to achieve the third object, according to claim 4 of the present invention, a rotary cylinder which is rotated by a motor provided in the apparatus casing, and is held outside the rotary cylinder via a bracket. A pipe end automatic seal welding method using a pipe end automatic seal welding device equipped with a welding head and a pipe expansion centering mechanism concentric with the rotary cylinder, wherein a rotary cylinder drive shaft equipped in the device, The drive shaft of the pipe expansion centering mechanism should be arranged on the same axis, and the shape of the device casing should be a horizontal tubular shape that the welding operator can hold with one hand, and the device casing material should be resin. It is characterized in that it is a pipe end automatic seal welding method that makes it easier to carry out the pipe end seal welding work by hand in the pipe end automatic seal welding device.

[0020]

According to the pipe end automatic seal welding apparatus according to the above-mentioned claims 1 and 3, the displacement sensor held by the welding device during the seal welding operation of the pipe end using the pipe end automatic seal welding apparatus. Since it is possible to detect the welding torch in the pipe end automatic seal welding device, specifically, the distance between the welding electrode tip position and the workpiece welding surface, the welding electrode tip and the welding object welding surface are detected. It is possible to perform seal welding while correcting the position (tilt) of the pipe end automatic seal welding device so that the distance between and is constant.

According to the pipe end automatic seal welding device of the second and third aspects, during the pipe end seal welding operation using the pipe end seal welding device, the temperature sensor held by the welding device is used. , It is possible to detect the temperature of the welded part of the work piece, thereby preventing abnormal heating of the work piece during welding work and avoiding embrittlement of the work piece due to high temperature heating. .

Further, according to the pipe end automatic seal welding apparatus of the present invention, since it is possible to continue the welding work by hand holding the seal welding device, a large pipe end automatic seal welding device can be used. There is no need for hanging equipment,
Further, it is easy to manually correct the position of the pipe end automatic seal welding apparatus, the inclination, or the fine movement adjustment thereof.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the drawings.

FIG. 1 shows each pipe end a of a large number of pipes A constituting a heat exchanger and a pipe that holds the plurality of pipes A through the use of the automatic pipe end seal welding apparatus according to the present invention. It is explanatory drawing which carries out TIG welding with the hole edge of the through-hole D pierced by the board B, and FIG. 2 shows the pipe edge automatic seal welding apparatus grasping mode at the time of the welding operation.

Reference numeral 21 denotes the pipe end automatic seal welding apparatus. The pipe end automatic seal welding apparatus 21 is made of a hard synthetic resin to reduce the weight, and further has a substantially cylindrical shape and is used by a welding operator. 2 has a casing 22 having a small diameter and a small size so that the welding operator can easily hold and operate it with one hand E. As shown in FIG.
A motor (not shown) is housed inside, and a rotary cylinder 23 that is rotated by the driving force of the motor is rotatably supported by the casing 22 and has a shaft center in front of the casing 22. Is projected in the direction.

Inside the rotary cylinder 23, the rotary cylinder 2 is provided.
An operating shaft 24, which is concentric with the shaft 3 and is supported so as to be capable of reciprocating in the axial direction, is internally provided, and a pipe expansion centering mechanism 25 is provided at the tip end of the operating shaft. A drive shaft (not shown) of a cylinder 26 that is integral with the casing 22 is connected to the tail end of the operating shaft 24, and the operation of the cylinder 26 causes the operating shaft 24 to move in the axial direction. The outer diameter of the pipe expanding centering mechanism 25 reciprocates, and the outer diameter of the pipe expanding centering mechanism 25 expands due to the forward power of the operating shaft 24 in the direction of the tip end of the pipe expanding centering mechanism 25. Since the outer diameter of the pipe expanding centering mechanism 25 is reduced by the returning force of the operating shaft 24 in the tail end direction, the pipe expanding centering mechanism 25 can be pulled out from the inside of the pipe A. it can.

The pipe expansion centering mechanism 25 is for positioning the pipe end automatic seal welding device 21 with respect to the pipe A. The structure and operation of the pipe expansion centering mechanism 25 are as follows.
For example, since it is known in Japanese Patent Application No. 11-339969, detailed description of its structure will be omitted.

The bracket 2 is provided outside the rotary cylinder 23.
A welding torch 29 is fixed via 8, and a tungsten electrode 30 is provided at the tip of this welding torch 29. The tip of the tungsten electrode 30 is at the welded portion between the pipe A and the tube sheet B. Bracket 28 so that it is located close to
It is positioned by.

Reference numeral 31 is a temperature sensor located near the welded portion. This temperature sensor 31 is the tip of the pipe end automatic seal welding device 21 and is fixed to the outside of the rotary cylinder 23 via a bracket 32. It is held and detects the heating temperature of the objects to be welded (tube A and tube sheet B).

As the temperature sensor usable in the present invention, it is desirable to use, for example, an ultra-small infrared radiation thermometer. A temperature indicator 33 for displaying the heating temperature of the object to be welded detected by the temperature sensor 31 is provided on the side surface of the casing 22.

The allowable measurement temperature of the temperature sensor 31 is preferably about 100 ° C to 500 ° C. The reason is that when the material of the pipe A and the tube sheet B, which are the objects to be welded, is a titanium material, it is possible to detect the embrittlement temperature (about 300 ° C.) or higher of the titanium material.

The detected temperature detected by the temperature sensor 31 is not only displayed on the temperature indicator 33,
A control circuit may be provided to automatically stop the welding when the detected temperature exceeds a set temperature (for example, 300 ° C.).

Reference numeral 34 denotes a displacement sensor fixed at the eccentric position of the pipe end automatic seal welding device 21 via the bracket 32. The displacement sensor 34 is connected to the displacement sensor 34 and the welding position. Is a sensor for measuring the distance, for example, by irradiating ultrasonic waves toward the welded position, the welded position and a specific position of the pipe end automatic seal welding device, specifically the welded position and the tungsten. The position with the tip of the electrode 30 is detected.

Then, the pipe end automatic seal welding device 21 is used.
During the welding operation around the pipe end by the displacement sensor 34
If the distance between the position to be welded and the tip of the tungsten electrode detected by is constant, "OK display" is displayed, and if the distance fluctuates, "NG display" is displayed and an indicator 35 for alerting the welding operator is displayed. It is provided on the side surface of 22.

The above is the description of the present embodiment. Next, the operation thereof will be described.
The casing shape of No. 1 is formed into a substantially horizontal tubular shape, and its outer diameter is also formed to have a small diameter that a welding operator can grasp with one hand E. Further, in this pipe end automatic seal welding apparatus, all drive shafts are on the same axis. The casing is made of resin, and the total weight of the casing is about 1/4 that of the conventional device.
Since the weight is reduced to about 2 kg, it is easy for the welding operator to directly grasp the pipe end automatic seal welding device and perform the welding operation. Therefore, the equipment such as the guide rail mechanism 13 and the spring balancer 14 described in the conventional example is unnecessary, and the preparation work for welding work can be omitted.
Economic efficiency is improved.

Further, in the welding work of holding the pipe end automatic seal welding device by hand and welding the periphery of the pipe end, the pipe end automatic seal is held so that the distance between the tip end position of the tungsten electrode 30 and the welded portion position does not change. The position of the welding device must be stably maintained, that is, the pipe end automatic seal welding device 21 is operated by the contact pressure between the outer peripheral surface of the pipe expanding centering mechanism 25 and the inner peripheral surface of the pipe A. , Although it is suppressed to fluctuate in the axial direction, if the orthogonality between the axial center of the pipe end automatic seal welding apparatus and the welding surface of the work to be welded is impaired due to changes in the posture of the welding operator, The distance between the annular surface to be welded and the tip of the tungsten electrode changes along the circumferential direction of the surface to be welded, which makes it impossible to perform welding with a uniform bead. To The axis of the pipe ends the automatic sealing welding apparatus 21 to always accurately perpendicular to the weld surface of the object to be welded, must be made the position regulation of the pipe end automatic sealing device 21 for gripping.

Therefore, the pipe end automatic seal welding apparatus 2 of the present invention is used.
1 is equipped with a displacement sensor 34 to constantly detect the distance between the tip of the tungsten electrode 30 which is automatically welded while moving circularly along the periphery of the pipe end welded object and the welding surface of the welded object. Then, when the detected distance changes, the operator can be prompted by the indicator 35.

Therefore, since the distance between the tip of the tungsten electrode and the surface to be welded of the automatic pipe-end seal welding device by hand can be stabilized, the pipe-end welding with uniform bead and high welding quality and high welding accuracy can be performed. It can be done with automatic edge seal welding equipment.

Further, the pipe end automatic seal welding apparatus according to the present invention is provided with the temperature sensor 31 for detecting the heating temperature of the object to be welded during the welding operation, and the detected temperature is displayed by the temperature indicator 33. The welding operator can successively detect the heating temperature of the workpiece while performing the welding operation.

Therefore, if the heating temperature of the object to be welded rises abnormally, the welding operation can be interrupted and the abnormal heating of the object to be welded can be suppressed. Can be prevented.

[0041]

As described above, according to the pipe end automatic seal welding apparatus according to the first and third aspects of the present invention, the distance between the tip of the tungsten electrode and the surface to be welded is detected during the seal welding work of the pipe end. Therefore, it is possible to continue the welding work while correcting the position (tilt) of the pipe end automatic seal welding device to grip so that the distance between the tungsten electrode tip and the surface to be welded is constant. This results in uniform beads and good quality pipe end welding.

According to the pipe end automatic seal welding apparatus of the second and third aspects, during the pipe end seal welding operation using the pipe end seal welding device, the temperature sensor held by the welding device is used. , It is possible to detect the temperature of the welded part of the work piece, thereby preventing abnormal heating of the work piece during welding work and avoiding embrittlement of the work piece due to high temperature heating. .

Further, according to the pipe end automatic seal welding apparatus of the fourth aspect, since it is possible to continue the welding work by hand holding the seal welding device, the large pipe end automatic seal welding apparatus can be continued. Equipment and members for suspending the pipe are not required, and it is easy to manually correct the position and inclination of the automatic pipe end seal welding device or fine-tune them, so the equipment is economical and the welding work is easy. The nature is enhanced.

[Brief description of drawings]

FIG. 1 is a side view showing a pipe end automatic seal welding apparatus according to the present invention.

FIG. 2 is an explanatory back view showing a pipe end automatic seal welding apparatus according to the present invention.

FIG. 3 is an explanatory view at the time of welding work using a conventional pipe end automatic seal welding device.

[Explanation of symbols]

21 Pipe end automatic seal welding equipment 22 casing 23 rotating cylinder 24 working axis 25 Tube expansion centering mechanism 26 cylinders 28 bracket 29 welding torch 30 Tungsten electrode 31 Temperature sensor 32 bracket 33 Temperature indicator 34 Displacement sensor 35 indicator

Continued front page    (72) Inventor Hirotaka Suga             5-8-6 Ryoke, Kawaguchi City, Saitama Stock Association             Inside Company Daiichi Mechatech F term (reference) 4E081 AA15 BA32 CA11 EA33 YH03                       YY06

Claims (4)

[Claims] 1. A rotating cylinder which is rotated by a motor provided in a casing of a welding apparatus, a welding head which is held on the outside of the rotating cylinder via a bracket, and which is located in front of the welding head and which rotates. In a pipe end automatic seal welding device equipped with a pipe expansion centering mechanism that is positioned coaxially with the pipe, a displacement sensor for detecting the distance between the pipe end automatic seal welding device and the position to be welded is used as a displacement sensor for the rotary cylinder. A pipe end automatic seal welding device, characterized in that it is fixed to a core position and further provided with an indicator for displaying a condition of a distance change detected by the displacement sensor. 2. A rotating cylinder which is rotated by a motor provided in a casing of a welding apparatus, a welding head which is held on the outside of the rotating cylinder via a bracket, and which is located in front of the welding head and has the above rotation. In a pipe end automatic seal welding device equipped with a pipe expansion centering mechanism positioned coaxially with a cylinder, a temperature sensor for detecting a heating temperature of a workpiece is held outside the rotary cylinder, and further detected by the temperature sensor. A pipe end automatic seal welding device, which is equipped with a temperature indicator for displaying the detected temperature. 3. A rotating cylinder which is rotated by a motor provided in a casing of a welding apparatus, a welding head which is held on the outside of the rotating cylinder via a bracket, and a rotating cylinder which is located in front of the welding head. In a pipe end automatic seal welding device equipped with a pipe expansion centering mechanism that is positioned coaxially with the pipe, a displacement sensor for detecting the distance between the pipe end automatic seal welding device and the position to be welded is used as a displacement sensor for the rotary cylinder. It is fixed to the core position and is provided with an indicator for displaying the status of the distance change detected by the displacement sensor, and further, a temperature sensor for detecting the heating temperature of the workpiece is held outside the rotary cylinder, and the temperature is also maintained. A pipe end automatic seal welding device, comprising a temperature indicator for displaying a temperature detected by a sensor. 4. A rotary cylinder which is rotated by a motor provided in the apparatus casing, a welding head which is held on the outside of the rotary cylinder via a bracket, and a pipe expanding centering mechanism which is concentric with the rotary cylinder. A pipe end automatic seal welding method using an equipped pipe end automatic seal welding device, wherein a rotary cylinder drive shaft and a drive shaft of a pipe expansion centering mechanism provided in the device are arranged on the same axis, and a device casing is provided. Is made into a horizontal tubular shape that the welding operator can hold with one hand, and the casing material is made of resin to reduce the weight, and the pipe end seal welding work is performed with the pipe end automatic seal welding device. This is a pipe end automatic seal welding method characterized in that it is easy to carry out by hand.