JPH0827386B2 - Laser pressure welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention performs pressurized injection of an inert gas into a fuel element that constitutes a fuel assembly used in a nuclear power plant when the fuel element is manufactured. At the same time, the present invention relates to a laser pressure welding device capable of plug-welding an inert gas injection hole with a laser beam.

"Prior Art" Conventionally, in a fuel element used for nuclear power generation, a lower end plug and a cladding pipe are first welded in a processing step, and a fuel pellet and an upper spring are inserted into the pipe to form a cladding pipe. The other end surface and the upper end plug are welded to complete one fuel element.

During this process, for some fuel elements, an inert gas (for example, helium gas) should be injected under pressure into the cladding tube, and the inert gas injection hole should be welded and sealed using a TIG welding machine. I have to.

During this welding operation, a method is adopted in which the inside of the cladding tube and the outside of the periphery of the inert gas injection hole are kept in the same inert gas atmosphere.

"Problems to be solved by the invention" However, an inert gas (for example, helium gas)
In the above pressurized atmosphere, the arc generation during welding may be uncertain, and in such a state, there is a problem that the electrode needs to be cleaned before welding.

"Means for Solving Problems" The present invention has been made in order to solve the above problems, and an object thereof is to provide a laser pressure welding apparatus which eliminates uncertainty during welding. It is configured as follows.

That is, the laser pressure welding apparatus of the present invention is fixed to a chamber formed by sandwiching both end surfaces of a cylindrical transparent body with side plates (A) and side plates (B) and the outer surface of the side plate (A). A shaft support flange, a support shaft rotatably supported by the shaft support flange, and a brush fixed to one end of the support shaft and slidingly contacting the inner surface of the chamber are provided, while the outer surface of the side plate (B) is provided. And a laser emitting portion disposed outside the transparent body, and an air supply hole of the side plate (A). The pipe (A) and the air supply valve connected to the side plate (B) and the pipe (B) and the exhaust valve connected to the exhaust hole of the side plate (B) are provided.

"Operation" The operation of the laser pressure welding apparatus according to the present invention will be described below.

This laser pressure welding apparatus has a structure in which no pressure is applied to the inside of the chamber when there is no fuel element.

First, when the fuel element passes through the pressure contact member and comes into contact with the end surface of the support shaft in the chamber, the support shaft is rotated by an external drive source, and the gas injection hole provided in the upper end plug of the fuel element is laser-exposed. Focus on the hole.

Next, when the pusher is pushed in a direction approaching the inside of the chamber by another pressure source, the pressure contact member elastically deforms and is pressed against the outer peripheral surface of the cladding tube and the inner peripheral surface of the pressure contact member mounting flange, and The pressurization is possible. At this time, the air supply valve and the exhaust valve are closed.

When the air supply valve is opened from the above state, an inert gas of a predetermined pressure (for example, helium gas) is injected, and an inert gas of the same pressure as in the chamber is also injected into the cladding tube through the gas injection hole of the upper end plug. Filled and closes the charge valve.

When the filling of the inert gas is completed, laser light is emitted to complete the plug welding of the gas injection hole of the upper end plug, and the exhaust valve is opened to return the inside of the chamber to atmospheric pressure. At this time, the fuel element is filled and sealed with an inert gas having a predetermined pressure.

Next, the pusher is returned in a direction in which it is separated from the inside of the chamber, and when the pressure contact member is restored, the fuel element is pulled out. After that, when the support shaft, to which the brush that slidably contacts the inner surface of the chamber is fixed, is rotated by an external power source, the molten gaseous substance of the upper end plug attached to the inner surface of the chamber is removed, and the air supply valve is opened to open the chamber. The inside is gas-purged to prepare for the next welding operation.

The above-described operations of rotating the brush and purging the gas may be performed when the inner surface of the chamber becomes dirty and welding of the gas injection hole of the upper end plug fails.

[Embodiment] FIGS. 1 and 2 are views showing a laser pressure welding apparatus A which is an embodiment of the present invention.

In these drawings, both end surfaces of a cylindrical transparent body 1 are sandwiched by side plates (A) 2 and side plates (B) 3 to form a chamber 4 and fixed with bolts 5.

A shaft support flange 6 is fixed to an outer surface of the side plate (A) 2, and a support shaft 9 is provided on an inner peripheral surface of the shaft support flange 6 via a thrust bearing 7 and a radial bearing 8.
Is rotatably supported through.

A brush 11 which is in sliding contact with the inner surface 10 of the chamber is fixed to one end of the support shaft 9. The other end of this support shaft 9 has a key
A V-pulley 13 is fitted with 12 as a detent, and is fixed with bolts 14.

On the other hand, a pressure-contacting member mounting flange 15 is fixed to the outer surface of the side plate (B) 3, and a pressure-contacting member 16 is provided so as to extend and contract inwardly to the pressure-contacting member mounting flange 15.

In addition, a pipe (A) 18 is provided in the air supply hole 17 of the side plate (A) 2.
And the air supply valve 19 is connected, while the pipe (B) 21 and the exhaust valve 22 are connected to the exhaust hole 20 of the side plate (B) 3.

Gaskets 23, 24, 25 are housed on the joint surfaces of the respective members configured as described above.

The chamber 4 composed of these members is fixed to the bottom plate 26 and is arranged in a predetermined work box.

In the laser pressure welding apparatus A having such a configuration, in order to perform welding work, first, when the fuel element 27 passes through the pressure contact member 16 and comes into contact with the end surface of the support shaft 9 in the chamber 4, an external drive source is generated. Rotate the support shaft 9 from (not shown),
Gas injection hole 29 provided in the upper end plug 28 of the fuel element 27
Focus on the laser light 30.

(The focus of the laser beam 30 can be adjusted by moving the laser beam generating end 31 in a direction of approaching or separating from the gas injection hole 29.) Next, another pressure source (see FIG. When the pusher 32 is pushed toward the inner surface 10 of the chamber by a not-shown), the pressure contact member 16 is elastically deformed and pressure-contacted to the outer peripheral surface of the covering pipe 33 and the inner peripheral surface of the pressure contact member mounting flange 15, thereby causing the chamber 4 The inside can be pressurized. (At this time, the air supply valve 19 and the exhaust valve 22 are closed.) When the air supply valve 19 is opened from the above state, an inert gas (for example, helium gas) having a predetermined pressure is applied in the direction of the arrow B in the chamber 4
The gas is injected into the inside of the chamber, and the coating pipe 33 is filled with the inert gas having the same pressure as that in the chamber 4 through the gas injection hole 29 of the upper end plug 28, and the air supply valve 19 is closed.

When the filling of the inert gas is completed, a laser beam 30 is emitted, the plug welding of the gas injection hole 29 of the upper end plug 28 is completed, the exhaust valve 22 is opened, and the inert gas in the chamber 4 is filled with an arrow. The air is exhausted in the C direction, and the pressure in the chamber 4 and the exhaust system is returned to the atmospheric pressure.

At this time, since the plug welding of the gas injection hole 29 of the upper end plug 28 is completed, the fuel element 27 is filled and sealed with an inert gas of a predetermined pressure, and the pressure welding work of the fuel element is performed. Is completed.

Next, the pusher 32 is returned in the direction away from the chamber 4, and when the pressure contact member 16 is restored, the fuel element 27 is pulled out.

After that, when the support shaft 9 to which the brush 11 slidingly contacting the chamber inner surface 10 is fixed is rotated by an external power source (not shown), the upper end plug 28 attached to the chamber inner surface 10 is rotated.
The molten gas is removed, the air supply valve 19 is opened, and the inside of the chamber is gas-purged to prepare for the next welding operation.

Since it is configured as described above, this laser pressure welding apparatus A can reliably perform the plug welding of the gas injection hole 29 of the upper end plug 28. In addition, since the electrodes used for TIG welding are unnecessary, the amount of non-combustible radioactive waste can be reduced.

[Advantages of the Invention] As described above, according to the present invention, a chamber formed by sandwiching both end surfaces of a tubular transparent body between a side plate (A) and a side plate (B), and the side plate (A). A shaft support flange fixed to an outer surface of the shaft, a support shaft rotatably supported by the shaft support flange, and a brush fixed to one end of the support shaft to slidably contact the inner surface of the chamber. A laser emitting portion provided with a press-contact member mounting flange fixed to the outer surface of the side plate (B) and a press-contact member provided in the press-contact member mounting flange so as to extend and contract, and a side plate. Since the pipe (A) and the air supply valve connected to the air supply hole of (A) and the pipe (B) and the exhaust valve connected to the exhaust hole of the side plate (B) are provided, the upper end plug It is possible to reliably perform plug welding of the gas injection hole, and moreover,
Since the electrode used for TIG welding is unnecessary, the effect of reducing the amount of non-combustible radioactive waste can be obtained.

[Brief description of drawings]

1 and 2 are views showing an embodiment of a laser pressure welding apparatus according to the present invention. FIG. 1 is a vertical sectional view, and FIG. 2 is a view taken along the line II-II in FIG. FIG. A ... Laser pressure welding device, 1 ... Transparent body, 2 ... Side plate (A), 3 ... Side plate (B), 4 ... Chamber, 6 ...
Shaft support flange, 9 ... Support shaft, 10 ... Chamber inner surface,
11 …… Brush, 15 …… Pressure contact member mounting flange, 16 …… Pressure contact member, 17 …… Air supply hole, 18 …… Piping (A), 19 …… Air supply valve, 20 …… Exhaust hole, 21 …… Piping (B), 22 ... Exhaust valve,
31 ... Laser light generation end.

Claims (1)

[Claims] 1. A chamber formed by sandwiching both end surfaces of a cylindrical transparent body between a side plate (A) and a side plate (B), and the side surface (A).
A shaft support flange fixed to the outer surface of the support shaft, a support shaft rotatably supported by the shaft support flange, and a brush fixed to one end of the support shaft and slidingly contacting the chamber inner surface. (B) a pressure-contact member mounting flange fixed to the outer surface, and a pressure-contact member elastically installed inside the pressure-contact member mounting flange, and a laser emitting portion disposed outside the transparent body, It is characterized by comprising a pipe (A) and an air supply valve connected to the air supply hole of the side plate (A), and a pipe (B) and an exhaust valve connected to the air discharge hole of the side plate (B). Laser pressure welding equipment.