JPS6321966Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an automatic nuclear fuel rod welding device that is capable of automatically measuring the weld bead diameter of a nuclear fuel rod whose end plug has been welded.

[Technical background of the invention and its problems]

Generally, nuclear fuel rods used in power reactors, etc., contain uranium dioxide in a cladding tube 1 made of a zirconium alloy or stainless steel tube, as shown in Figure 1.
A predetermined number of pellets 2 such as UO ₂ are loaded, a spring 3 is inserted to press the pellets 2 to one side, and an end plug 4 made of the same material as the cladding tube 1 is welded to one end of the cladding tube 1 in advance. After loading the pellets, an end plug 5 made of the same material as the end plug 4 is welded to the end where the pellets were inserted.

Incidentally, the diameter of the weld bead where the end plugs 4 and 5 of the nuclear fuel rod are welded needs to be controlled to a predetermined size or less in order to avoid any problems when assembled as a nuclear fuel assembly.

However, conventionally, the diameter of the weld bead has been manually measured by an operator using a micrometer or a ring gauge. therefore,
In order to perform this measurement, the fuel rod must be pulled out of the welding chamber after welding, and then the movement must be stopped, which is a bottleneck in automatic welding systems that continuously transport the fuel rod. was.

[Purpose of invention]

In view of these points, the present invention aims to provide an automatic nuclear fuel rod welding device that automatically measures the outer diameter of a weld bead.

[Summary of the idea]

This invention uses a laser to measure the weld bead diameter of nuclear fuel rods on the side of the transport path for nuclear fuel rods that are pulled out from the welding chamber. It is characterized by being able to automatically measure the outer diameter of the weld bead.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, reference numeral 6 denotes a welding chamber having a welding torch 7. One side wall of the welding chamber 6 is provided with an opening 8 into which the end of the cladding tube 1 can be freely inserted, and the other wall side is provided with an opening 8 into which the end of the cladding tube 1 can be inserted. An end plug press-fitting mechanism 9 is provided opposite the opening 8 for holding the end plug 4 or 5 and press-fitting it into one end of the nuclear fuel cladding tube.

Thus, the cladding tube 1 or a nuclear fuel rod in which a predetermined number of fuel pellets 2 and springs 3 are inserted is inserted into the welding chamber 6 through the opening 8, and the end plug press-fitting mechanism 9 closes the nuclear fuel rod. An end plug 4 or 5 is press-fitted into the end of the cladding tube 1, and the end plug 4 or 5 is welded using a welding torch 7.

By the way, in the middle of the transport path for pulling out the nuclear fuel rods whose end plugs 4 or 5 have been welded from the welding chamber 6, there are support wheels 10, 10 that support the cladding tube 1 of the nuclear fuel rods and a drive motor 11. A drive wheel 12 that is rotatably driven and pressed against the outer surface of the nuclear fuel rod is arranged so as to be inclined at a predetermined angle with respect to the axis of the nuclear fuel rod.

In addition, the welding chamber 6 is connected to the support ring 10, etc.
A nuclear fuel rod end detection sensor 13 for detecting the end of the end plug 4 or 5 of the cladding tube 1 of the nuclear fuel rod pulled out from the welding chamber 6 is disposed on one side of the delivery path. There is. Further, when the end of the end plug 4 or 5 is detected by the nuclear fuel rod end detection sensor 13, a position facing the weld bead 14 is activated by the signal from the sensor 13 and emits a laser beam. A laser transmitter 15 is provided at a position facing the laser transmitter 15 across the nuclear fuel rod transport path, and receives the laser beam and calculates the maximum diameter of the weld bead based on the amount of received light. A laser receiver 16 is provided for this purpose.

When the nuclear fuel rod whose end plug 4 or 5 has been welded is pulled out from the welding chamber 6, the cladding tube 1 of the nuclear fuel rod is supported by the support wheels 10, 10 and is driven by the drive motor 11. It is moved in the axial direction while being rotated by the drive wheels 12. Therefore, when the end of the end plug 4 or 5 of the nuclear fuel rod comes to the position of the nuclear fuel rod end detection sensor 13, the sensor detects that the end of the end plug 4 or 5 has reached a predetermined position. The drive motor 11 is controlled by the detection signal, and the nuclear fuel rod is decelerated to the rotational speed and movement speed necessary for measuring the weld bead portion 14.

Meanwhile, at the same time, the laser transmitter 15 is activated by a signal from the sensor 13, and a laser beam is emitted.The laser beam is received by the laser receiver 16, and the amount of the received light is calculated to calculate the maximum The diameter is measured.

When the measurement is completed in this manner, the speed of the drive motor 11 is increased, the moving speed of the nuclear fuel rod is returned to the original speed, and the nuclear fuel rod is transported to a predetermined position.

[Effect of idea]

As explained above, in the present invention, a laser-based weld bead diameter measuring device for nuclear fuel rods is installed on the side of the transport path for nuclear fuel rods pulled out from the welding chamber, so that the nuclear fuel rods pulled out from the welding chamber are The outer diameter of the weld bead can be measured without manual work by the operator.
Moreover, the measurement can be performed while the nuclear fuel rod is moving, and the measurement can be performed continuously without the need to stop the movement of the nuclear fuel rod each time, thereby improving the operating efficiency of the welding device itself.

Moreover, since the diameter of the weld bead portion is measured while rotating the nuclear fuel rod, the outer diameter is guaranteed at any point in the circumferential direction, making it possible to achieve extremely high measurement accuracy.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view of a nuclear fuel rod, and FIG. 2 is a schematic diagram of an automatic nuclear fuel rod welding apparatus of the present invention. DESCRIPTION OF SYMBOLS 1... Cladding tube, 5... End plug, 6... Welding chamber, 10... Support wheel, 11... Drive motor, 1
2... Drive wheel, 13... Nuclear fuel rod end detection sensor, 15... Laser transmitter, 16... Laser receiver.

Claims (1)

[Scope of utility model registration request] A laser transmitter that is activated by a signal from a nuclear fuel rod end detection sensor and emits a laser beam is placed on the side of the nuclear fuel rod removal path to be pulled out from the welding chamber, and a laser transmitter that emits a laser beam is placed across the nuclear fuel rod removal path. A laser receiver is disposed facing the laser beam, and is configured to receive the laser beam and calculate the maximum diameter of the weld bead based on the amount of received light. An automatic nuclear fuel rod welding device characterized by being provided with a rotation drive device for rotating.