JPH095487A - End face melting device for fuel rod end plug - Google Patents

Abstract

PURPOSE: To improve the work efficiency and attain stable quality via automatic handling by a robot by miniaturizing gas chambers when melting the end face of a fuel rod end plug. CONSTITUTION: This end face melting device is provided with multiple openable/ closable gas chambers 1 each storing one end plug 3 and a robot carrying-in/out the end plug 3 to each gas chamber 1. Each gas chamber 1 is provided with a fixing means 4 fixing the end plug 3 while exposing the end face 3a to be melted and a melting means 5 melting the end face of the fixed end plug 3 respectively, and a gas feeding means 6 feeding the prescribed gas to the chamber 1 is connected to each chamber 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting device for an end surface of an end plug of a nuclear fuel rod for melting the end surface of the end plug by metallurgical means.

[0002]

2. Description of the Related Art An end plug of a fuel rod is manufactured by dimensionally cutting a raw rod of the material. The defect is taken over by the end plug.

Since an internal defect of the round rod is apt to occur at the center of the cylinder in manufacturing, if an end plug is manufactured by using the round rod having the defect as it is, a leak occurs from the inside of the fuel rod through the defect. there's a possibility that.

Therefore, the applicant of the present application is the Japanese Utility Model Publication No. 63-36.
As disclosed in Japanese Patent No. 312, the above problem is solved by melting the inner end surface of the end plug by a metallurgical step, and forming a melted portion for preventing the leak at the center of the end surface.

By the way, the above-mentioned end plugs are melted in a chamber filled with an inert gas in order to prevent coloring, but conventionally, a plurality of end plugs are housed in a large chamber and melted manually. Was going on.

[0006]

However, in the above-mentioned conventional large-sized chamber, it takes a long time to evacuate the chamber and to replace gas, and it is difficult to automate the handling of the end plug by the robot in the chamber. There's a problem.

Further, there is variation in melting skill in the above-mentioned manual work, and it is technically not easy to obtain a melt end plug having a constant quality with respect to a melting point, a melt diameter and the like.

On the other hand, the problem of coloring is that once the atmosphere in the chamber becomes abnormal, coloring occurs in all of the plurality of end plugs in the chamber, increasing the defective rate. In addition, since the amount of one batch also increases, it may be delayed in recognizing the above-mentioned abnormalities such as coloring when performing an appearance inspection after melting one batch. In particular, it is difficult for the melting end plug placed in the large chamber to notice an abnormal appearance or the like through the window.

An object of the present invention is to solve the above-mentioned problems by dealing with the above situation and finding a new structure in the chamber and the melting means.

[0010]

That is, the features of the end face melting device of the present invention which meet the above object are that a plurality of openable and closable gas chambers for accommodating the end plugs one by one and these gas chambers. The chamber is equipped with a robot for loading and unloading the end plug, fixing means for fixing the end plug by exposing the end face to be melted in each of these chambers, and melting the end face of the fixed end plug. The melting means for carrying out the heating and the gas supply means for supplying a predetermined gas into the chambers are respectively connected to the respective chambers.

[0011]

In the melting apparatus of the present invention, since the plurality of gas chambers can be miniaturized, the evacuation time and the gas replacement time of the inert gas can be shortened to improve the work efficiency, and the chamber 1 unit can be used. Since it is sufficient to carry in and carry out one end plug per hit, automation of handling of the end plug by the robot becomes easy.

Furthermore, it is possible to automate the melting of the end plugs by using a welding machine such as Tig or a laser for the melting means arranged in the gas chamber. It is possible to obtain a stable fused plug having a constant quality.

With respect to the problem of coloring, since the appearance of the end plug after melting can be confirmed in almost real time, even if a defect occurs, it can be stopped by the actual product to reduce the defect rate. Is.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view showing an end face melting apparatus for an end plug according to an embodiment of the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a right side view of the same. Five gas chambers 1 for accommodating each one are provided on a base 2 so as to be freely opened and closed.

In each of the chambers 1 of these five machines, as shown in FIG. 4, fixing means 4 for fixing the end plug 3 with the end surface 3a of the melting end plug 3 exposed, and this fixing. A melting means 5 for melting the end face 3a of the end plug 3 is attached, and a gas supply means 6 for supplying an inert gas such as argon gas into the chamber 1 is connected to each chamber 1. Has been done.

The chamber 1 is, as shown in FIG.
The lower case 7 fixed to the base 2 and the lower case 7
And an electrode cover 8 which covers like a lid, and the electrode cover 8 is opened and closed by vertically moving along a guide rod 10 by a linear motor 9 as shown in FIGS. Is supposed to do. At this time, the O-ring R seals the chamber 1.

As shown in FIG. 4, the fixing means 4 is formed by a chill 15 fixed to the lower case 7, and has an insertion hole 11 into which the end plug 3 is fitted, and the end plug 3 from the bottom of the insertion hole 11. It has a cylindrical end plug receiver 12, and is fixed by fitting the end plug 3 into a recess formed by these. Further, when the end plug 3 is taken out from the fixing means 4, the push rod 13 which is inserted into the cylindrical end plug receiver 12 is moved upward by the cylinder 14, and the end plug 3 is pushed out from the insertion hole 11 as required and taken out. To facilitate. Further, a sensor S for detecting whether or not the end plug 3 is properly seated is provided at the bottom of the insertion hole 11.

The melting means 5 has an electrode 16 protruding into the electrode cover 8 with a predetermined gap from the fixed end plug 3, and a cable for guiding a current to the electrode 16 and the end plug 3. (Not shown). The electrode 16 is integrally fixed to the electrode cover 8 so as to move up and down together with the electrode cover 8. This melting means 5 uses an arc welding machine, but it is also possible to use a welding machine such as a laser.

In this embodiment, the gas supply means 6 supplies an inert gas to the chamber 1 through the introduction hole 18 shown in FIG. 4 after the vacuum pump 17 (see FIG. 3) for evacuating the chamber 1 is activated. It is supposed to be supplied. In addition,
The supplied gas escapes into the air when the chamber 1 is opened after the end plug is melted.

On the other hand, in this embodiment, as shown in FIG. 1, a robot 19 is provided near the center of the pedestal 2, and the arm 20 of this robot supplies the end plugs 3 into each chamber 1. ing.

As shown in FIG. 5, the robot 19 has an end plug hand 21 and a holder hand 22 at the tip of an arm 20.
As shown in FIG. 6, the end plug hand 21 holds a part of the end plug 3 by sucking it into the hole 21a, and the holder hand 22 has a large number as shown in FIG. The holder 23 is held so as to sandwich the end edge portion of the holder 23 on which the end plug is placed. These end plug hands 2
1 and the holder hand 22 are attached to the arm 20 so as to be rotatable around a shaft 24.

On the other hand, reference numeral 25 shown in FIG. 1 is a holder supply section, which is in the shape of a tray which rotates 180 ° in order to supply the holder 23 into the dust cover 26. Further, 27 is a holder carry-out section for taking out the holder 23 from the inside of the dust cover 26.
5 has the same configuration.

That is, in this embodiment, the holder 23 on which the end plug 3 is placed is put into the dust cover 26 by rotating the holder supply unit 25, and the holder hand 22 of the robot 19 conveys the holder 23 from there. Then, it is once placed on the fixed part 28, and the end plugs 3 are carried in or out from the holder 23 on the fixed part 28 by the end plug hand 21 one by one.

The melted end plug 3 carried out is again fixed to the fixing portion 28.
The holder 23 is returned to the holder 23, and when the predetermined number of the end plugs 3 are accumulated, the holder 23 is conveyed to the holder unloading section 27 by the robot 19. Then, the holder 23 of the holder carry-out section 27 is taken out from the dust cover 26 of the apparatus by rotating the holder carry-out section 27.

Therefore, in the melting apparatus of the above-mentioned embodiment, the operator sets the holder 23 of the end plug 3 before melting in the holder supply section 25 as described above, and thereafter, from the holder unloading section 27 after melting. The holder 23 of the end plug 3 is simply taken out, and the subsequent transfer of the end plug 3 is performed by the robot 19 and the process from opening / closing of the chamber 1 to melting is automatically and unmanned. For reference, a flow chart of the above apparatus is shown in FIG.

In this embodiment, 50 end plugs 3 are placed on one holder, and the end plug end face 3a can be melted by Tig welding in the chamber 1 of the five machines in an argon gas atmosphere. When 5 holders were continuously operated, the above 1 cycle was completed in about 2 to several hours depending on the operation speed.

Further, in the apparatus of the above embodiment, the melting conditions such as the vacuum time, the type of gas in the chamber, the time for replacing the gas, the melting current and the cooling time can be easily changed according to the type of the end plug 3. It is possible to obtain a good and constant quality fused end plug.

[0029]

As described above, the melting device for the end surface of the end plug of the present invention has a robot for transporting the end plug, and a fixing means for fixing the end plug in a plurality of chambers for individually storing the end plug. And a melting means, respectively, and gas supply means for supplying a predetermined gas are respectively connected to the respective chambers, and since the plurality of gas chambers can all be downsized, the gas replacement time can be shortened. The efficiency of the work can be improved, and since only one end plug needs to be carried in and out per chamber, it is easy to automate the end plug handling by the robot. Since the melting of the end plug can be performed automatically by using, the remarkable effect is obtained that a melted end plug having a constant melting point and melt diameter and having a constant quality can be produced.

Since the state of the end plug after melting can be confirmed in almost real time, even if a coloring defect occurs, it can be stopped by the actual product to reduce the defect rate and by moving the chambers individually, It is possible to manufacture the required number of melt end plugs, and further, it is possible to reduce the manufacturing cost by manpower saving by the above automation.

[Brief description of drawings]

FIG. 1 is a plan view showing an end face melting device for an end plug according to an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a right side view of the same.

FIG. 4 is a cross-sectional view showing the vicinity of the chamber of the same embodiment.

FIG. 5 is a side view showing the robot of the embodiment.

FIG. 6 is an enlarged view showing an end plug hand and a holder hand of the robot.

FIG. 7 is a flowchart showing the operation of the melting apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 1 Gas Chamber 2 Platform 3 End Plug 3a End Surface of End Plug 4 Fixing Means 5 Melting Means 6 Gas Supply Means 7 Lower Case 8 Electrode Cover 9 Linear Motor 10 Guide Rod 11 Insertion Hole 12 End Plug Receptor 13 Push Rod 14 Cylinder 15 Chill 16 Electrode 17 Vacuum pump 18 Introductory hole 19 Robot 20 Robot arm 21 End plug hand 21a Hole 22 Holder hand 23 Holder 24 Shaft 25 Holder supply part 26 Dust cover 27 Holder unloading part 28 Fixed part R O ring S sensor

Claims (1)

[Claims] 1. An apparatus for metallurgically melting end surfaces of fuel rod end plugs, comprising a plurality of openable and closable gas chambers for accommodating the end plugs one by one, and carrying the end plugs into these gas chambers.・ A robot for carrying out is provided, and each of these chambers is provided with a fixing means for exposing the melting end surface to fix the end plug, and a melting means for melting the end surface of the fixed end plug. In addition, the device for melting the end face of the fuel rod end plug is characterized in that gas supply means for supplying a predetermined gas into the chamber are connected to the respective chambers.