JPH0511038Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention is suitable for welding the end plates of the hold-down assembly of nuclear fuel assemblies and non-nuclear fuel core components such as burnable poison rods and thimble plugs. This relates to the welding jig used.

``Prior Art'' As is well known, in a nuclear fuel assembly, there are multiple burnable poison rods between the fuel rods, which serve to suppress excess reactivity at the initial stage of fuel combustion and extend the life of the fuel. Equipped.

The burnable poison stick 1 is, as shown in FIG.
The threaded portion formed at the upper end thereof is inserted into the hole of the end plate 4 of the hold-down assembly 3 and screwed with a nut 5, and the pin 7 is inserted into the groove portion 6 formed at the upper end of the threaded portion. The pin 7 is attached by welding both ends of the pin 7 to the nut 5 and fixing the nut 5 and the threaded portion.

By the way, in order to weld both ends of the pin 7 to the nut 5 with the welding torch 9, it is necessary to clamp any part of the hole-down assembly 3 with ground pliers 10, but there is no bar on the end plate 4. Since a large number of bull poison bars 1 are screwed together, the clamping part is narrow, and a hold-down spring 12 is attached to the cylindrical part 11, so it cannot be clamped, so one end of the hold-down bar 8 is clamped. I was going.

"Problem to be solved by the invention" However, when one end of the hold-down bar 8 is clamped with the above-mentioned ordinary grounding pliers 10,
As shown in FIG. 5, it may be difficult for the grounding pliers 10 to come into close contact with the side surface of the hold-down bar 8, and some hold-down bars may have bent ends as shown in FIG. If a load is applied to the grounding pliers 10 from the grounding wire 10a and this load is greater than the clamping force of the grounding pliers 10, the hold down bar 8 may be scratched by the grounding pliers 10. Also, if the clamping force of the grounding pliers 10 is increased so as not to succumb to the above-mentioned load, the holding down bar 8 may be scratched by the grounding pliers 10, and the grounding pliers 10 may be damaged by the above-mentioned load, etc. during welding. As a result, the grounding pliers 10 and the hold-down bar 8 move and momentarily move slightly away from the hold-down bar 8 or fall off, causing sparks between the grounding pliers 10 and the hold-down bar 8, resulting in a decrease in welding efficiency. The problem was that it was dangerous.

The purpose of this invention is to provide a welding jig that can solve the above problems.

"Means for Solving the Problem" The welding jig of this invention includes a support part, a rotary plate rotatably supported by the support part, and a tip end extending from the rotary plate in the axial direction of the rotary plate. a pair of arms formed with engaging portions to which a workpiece is fixed;
The rotary plate is provided with a pressing part that is movable between the pair of arms in the same direction as the longitudinal direction of the arms, and presses and fixes the workpiece to the engaging part. .

"Operation" In the welding jig of this invention, after inserting the arm formed on the rotary plate into the workpiece, the rotary plate is rotated to lock the engaging part formed at the tip of the arm to the workpiece. Then, the pressing part presses the workpiece to press and fix it to the engaging part.

"Embodiment" An embodiment of the welding jig of this invention will be described below with reference to FIGS. 1 and 3.

In these figures, reference numeral 20 indicates a support portion.
This support portion 20 includes a horizontal plate 20a and a horizontal plate 20a.
It is composed of a vertical plate 20b formed at the right end portion of a. The horizontal plate 20a is fixed to the upper surface of a slide plate 21, and the slide plate 21 is provided on a rail portion 22 so as to be movable in the left-right direction.

Further, on the right side of the vertical plate 20b of the support section 20, an aluminum rotating plate 25 is rotatably provided by a cam follower bearing (not shown). A pair of arms 26, 26 extending toward the right are provided on the outer peripheral edge of the right end surface of the rotary plate 25.
are formed symmetrically with respect to the rotation axis of the rotating plate 25, and L-shaped locking claws (engaging portions) 27, 27 are formed at the tips of the arms 26, 26.

Furthermore, a female thread 28 is formed in the center of the right end surface of the rotating plate 25, and a male thread 29 made of nylon is screwed into the female thread 28 so as to be movable in the axial direction of the rotating plate 25. A pressing portion 30 made of nylon that presses the upper end surface 11a of the cylindrical portion 11 of the hold-down assembly 3 is formed at the tip of the male screw 29.

Next, a method of using the welding jig having the above configuration will be explained.

First, the slide plate 2 moves over the rail part 22 provided on the extension of the cylindrical part 11 of the hold-down assembly 3.
1 to the right and insert the tips of the pair of arms 26, 26 formed on the rotary plate 25 around the cylindrical part 11 with the hold down bar 8 in between. 26, 26
The locking claws 27, 27 at the tip of the hold-down bar 8 are locked to the hold-down bar 8.

Next, the male screw 29 is rotated and the hold-down assembly 3 is pressed by the pressing part 30 formed at the tip thereof.
By pressing the upper end surface 11a of the cylindrical portion 11, the hold down bar 8 is pressed and fixed to the locking claws 27, 27. This securely fixes the welding jig to the holddown assembly 3.

Therefore, in the above welding jig, the arms 26, 26 formed on the rotary plate 25 are inserted into the hold-down assembly 3 so as to sandwich the hold-down bar 8, and then the arms 26, 26 are rotated by rotating the rotary plate 25.
By locking the locking claws 27, 27 at the tips of 6 to the hold-down bar 8, and pressing the cylindrical portion 11 with the pressing part 30, the hold-down bar 8 is pressed and fixed to the locking claws 27, 27. It is securely fixed to the hold down assembly 3.

Therefore, according to the above-mentioned welding jig, the hold down bar 8 is
This prevents the metal from being difficult to hold, damaging the hold-down bar 8, moving during welding, or falling off the hold-down bar 8 and causing sparks, making it efficient and safe. Able to perform welding work.

Furthermore, since the portion of the hold-down bar 8 located symmetrically with respect to the axis of the hold-down assembly 3 is pressed and fixed to the locking claws 27, 27 of the pair of arms 26, 26, the fixing balance is improved. is also excellent.

Furthermore, after moving the slide plate toward the cylindrical part 11 of the hold-down assembly 3 along the rail part 22, the rotary plate 25 is rotated, and then the male screw 2
Since the hold-down bar 8 is pressed and fixed to the locking claws 27, 27 of the arms 26, 26 by rotating the bar 9 and moving the pressing part 30, this work can be easily automated. .

In addition, in the above embodiment, the pressing part 30 has a male thread 29.
However, the present invention is not limited to this, and the movement may be performed using various cylinders, springs, etc., for example.

"Effect of the invention" As explained above, according to the welding jig of this invention, after inserting the arm formed on the rotary plate into the workpiece, the rotary plate is rotated and the welding jig formed at the tip of the arm is inserted into the workpiece. The joint part locks onto the workpiece, and the pressing part presses the workpiece to secure it to the engaging part, making it difficult to clamp the workpiece and preventing scratches on the workpiece, unlike conventional earthing pliers. Sparks are not generated due to attachment, movement during welding, or falling off from the workpiece, and therefore welding work can be performed efficiently and safely, and automation can be easily performed.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the welding jig of this invention, with Figure 1 being a perspective view of the welding jig, and Figure 2 showing the welding jig fixed to the hold-down assembly. FIG. 3 is a cross-sectional view taken along the - line in FIG. 2, FIG. 4 is a side view showing the conventional grounding pliers fixed to the hold-down assembly, and FIG. 5 is a cross-sectional view taken from the - line in FIG. The line sectional view and FIG. 6 are plan views of the hold-down bar with bent ends. 3...Hold down assembly (work), 20
...Support part, 25 ... Rotating plate, 26 ... Arm,
27... Locking claw (engaging part), 30... Pressing part.

Claims (1)

[Scope of utility model registration request] A supporting part, a rotating plate rotatably supported by the supporting part, and a pair of engaging parts extending from the rotating plate in the axial direction of the rotating plate and having a distal end thereof formed with an engaging part to which a workpiece is fixed. an arm, and a pressing part provided on the rotary plate so as to be movable between the pair of arms in the same direction as the longitudinal direction of the arm, and pressing and fixing the work to the engaging part. A welding jig characterized by: