JPH06130180A - Refueling machine gripper for fast breeder reactor - Google Patents

Abstract

PURPOSE:To rotate a fuel in grasping state during a refueling of a fast breeder reactor. CONSTITUTION:To a refueling machine provided with a gripper 3, a spline 6 and a gripper finger opening mechanism 4 connected to a coupling part 6a above the spline and an opening rod 8, an arm is coupled to a coupling part 6a with a specified marginal angle and a gear 5 for rotating the gripper fixed below the spline 6, a gripper gear 3a gearing with this gear 5 and a bearing 14 supporting the gripper fixed to a support part 1 are provided. When the spline 6 is rotated over the marginal angle, the gear 5 for rotating the gripper and the gripper gear 3a are geared and the gripper 3 is rotated to adjust the direction of a fuel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel exchanger gripper having a self-orientation function for a fast breeder reactor.

[0002]

2. Description of the Related Art A fast breeder reactor has a faster rate of producing new fissionable substances by absorbing neutrons into a nuclear source material than it consumes nuclear fuel required for a chain reaction by using fast neutrons. Since it is a furnace and heat is taken out from a small core, sodium, which has a good heat transport capacity, is used as a coolant. Since sodium must not come into contact with air, the reactor vessel is sealed and the liquid level is covered with an inert gas. The furnace top lid strictly protects the airtightness and also serves as a shield. However, since it is necessary to change the fuel without opening the lid, various measures are required.

FIG. 7 is a sectional view of a fuel exchanger of a fast breeder reactor, (A) is a vertical sectional view, and (B) is a sectional view taken along line BB of (A). A large rotation plug 12 and a small rotation plug 11 which is eccentrically attached to the large rotation plug 12 are arranged in the upper part of the core, and the small rotation plug 11 is provided with a telescopic arm fuel exchange machine and a direct drive type fuel exchange machine 10. Reference numeral 13 is an upper core mechanism. FIG. 8 is a configuration diagram of the telescopic arm type fuel exchanger of FIG. 7. At the time of refueling, in order to move the upper core mechanism from above the core and to the access point required for refueling, the telescopic arm fuel exchanger is mounted on the small rotating plug 11 arranged eccentrically from the center of the core. The fuel exchanger is moved to the vicinity of the fuel to be replaced, and the fuel is inserted and replaced from the upper part of the core. The telescopic arm type fuel exchanger 9 raises and lowers an internal barrel built in the main barrel by rotating a lifting ball screw shaft, and raises and lowers a stem (not shown) coupled to the internal barrel. By raising and lowering this stem, the entire arm can be expanded and contracted in the horizontal direction while keeping the gripper 3 vertical. The fuel of the fast breeder reactor has a substantially hexagonal columnar shape whose horizontal cross section is hexagonal, and the fuel is inserted so that the sides of the surrounding fuel are aligned. For this reason, there is a self-orientation mechanism called a self-orientation mechanism by the unevenness along the longitudinal direction on the outer surface of the fuel itself, which allows the fuel to be smoothly inserted.
If displaced, the adjacent fuel may be difficult to insert,
It may lead to insertion failure. Since the mechanism is complicated to rotate the fuel by the fuel exchange machine, conventionally, when the fuel is put into the reactor without rotating the fuel by the fuel exchange machine, the directions of the adjacent fuels match at the fuel insertion position. And calculated the angles so that the angles would match.

[0004]

When the fuel is put into the furnace, it is time-consuming to calculate so that the directions of the adjacent fuels match at the fuel insertion position, and the fuel exchanger has the function of rotating the fuel. May complicate the mechanism. Further, in the future, the rotating plug will be eliminated and the space for the fuel exchange will be secured by raising or removing the upper core mechanism from the reactor during the fuel exchange.
It is expected that the fuel will be exchanged in the entire furnace by using a single refueling machine. At this time, it is desirable to provide the fuel exchanger with a function of rotating the fuel in order to back up the self-orientation of the fuel.

It is an object of the present invention to provide a refueling machine gripper which can be rotated while grasping fuel during refueling of a fast breeder reactor.

[0006]

A support member coupled to a ball screw shaft, a gripper supported by the support member and having gripper claws, a spline attached to the support member, and an engaging member above the spline. A gripper claw opening / closing mechanism connected to the gripper claw via an arm and an opening / closing rod connected to the gripper claw opening / closing mechanism, and the arm is engaged in the refueling machine of a fast breeder reactor using liquid metal as a coolant. A fan-shaped gripper rotating gear attached to the lower part of the spline, a gripper gear meshing with the gripper rotating gear, and a gripper attached to the support member while being engaged with the member at a predetermined margin angle. And a bearing that rotatably supports
When rotating the spline beyond the margin angle,
The above object is achieved by meshing the gripper rotating gear with the gripper gear and rotating the gripper.

[0007]

According to the present invention, the arm is engaged with the engaging member on the upper portion of the spline with a predetermined allowance angle, and therefore the arm does not rotate even if the spline is rotated by the allowance angle. However, by rotating the spline, the fan-shaped gripper rotation gear attached to the lower part of the spline is rotated, the gripper rotation gear and the gripper gear are meshed, and the gripper can be rotated to determine the fuel insertion position. . In this way, the refueling machine gripper can be provided with the function of backing up the fuel self-orientation.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a fuel exchanger gripper according to an embodiment of the present invention. In FIG. 1, the ball screw shaft 2
Is rotated, and the support member 1 connected to this shaft is moved up and down. The gripper 3 includes a gripper claw 7 and is rotatably supported by the support member 1 via a bearing 14. The support member 1 includes a spline 6, a gripper claw opening / closing mechanism 4 connected to an engaging member 6 a above the spline 6 via an arm 4 a, and a claw opening / closing rod 8 coupled to the gripper claw opening / closing mechanism 4. . A fan-shaped gripper rotating gear 5 attached to the lower part of the spline 6 and a gripper rotating gear 3a attached to the upper part of the gripper 3 are provided.

FIG. 2 is an enlarged view of the gripper claw opening / closing mechanism of FIG. 1, and FIG. 3 is a view in the direction of arrow III in FIG. Spline 6
When is rotated, the engaging member 6a attached to the spline 6 engages with the arm 4a, the arm 4a moves left and right in the direction of the arrow, and the pawl opening / closing rod 8 connected to the gripper pawl opening / closing mechanism 4 is moved. Move up and down. The arm 4a has a predetermined allowance angle δ with respect to the engaging member. When the spline 6 rotates, the engaging member 6a and the arm 4a do not engage with each other during the allowance angle δ (about 60 °), but the allowance angle δ. When exceeding, the engaging member 6a and the arm 4a are engaged.

The fuel handling sequence of the fuel exchanger gripper of the present invention will be described. 4A and 4B are explanatory views showing a fuel gripping operation of the fuel exchanger gripper of the present invention. FIG. 4A is a view showing the movement of the spline, FIG. 4B is a plan view showing the movement of the gripper claw opening / closing mechanism, and FIG. FIG. 6 is a front view showing the movement of the opening / closing mechanism, and FIG. 6D is a view showing the movement of the gripper rotating gear. 5A and 5B are explanatory views showing an orientation determining operation of the fuel exchanger gripper according to the present invention. FIG. 5A is a view showing the movement of the spline, FIG. 5B is a plan view showing the movement of the gripper claw opening / closing mechanism, and FIG. Front view showing the opening and closing mechanism in motion,
FIG. 6D is a diagram showing the movement of the gripper rotating gear. FIG. 6 is an explanatory view showing the fuel release operation of the fuel exchanger gripper of the present invention, (A) is a view showing the movement of the spline,
(B) is a plan view showing the movement of the gripper claw opening / closing mechanism,
(C) is a front view showing the movement of the gripper opening / closing mechanism, (D)
FIG. 6 is a diagram showing the movement of a gripper rotating gear.

(1) Fuel grip First, the ball screw shaft 2 is rotated to the right as shown in FIG. 4 (A) to lower the support member 1 and the gripper 3 to the fuel position. Rotate the spline 6 to move the arm 4 to the position shown in FIG.
When moved to the position indicated by the solid line in (B), the gripper claw opening / closing mechanism 4 connected to the arm 4 becomes as shown in FIG. 4 (C),
The claw opening / closing rod 8 descends and engages with the gripper claw 7, and opens the gripper claw 7 to lock (grasp) the fuel. At that time, the gripper rotating gear 5 rotates to the position indicated by the solid line in FIG. 4D, but does not mesh with the gripper gear 3a. (2) Fuel withdrawal The ball screw shaft 2 is reversed and the gripper 3 is raised to withdraw the fuel. (3) Movement The extracted fuel is moved to the fuel insertion position. (4) The orientation determining spline 6 is further rotated toward the gripper claw opening side. At that time, the gripper claw opening / closing mechanism is in the claw closed position as shown in FIGS. 5 (B) and 5 (C), and the fuel is still held. The gripper rotating gear 5 meshes with the gripper gear 3a,
Orient the fuel. (5) Insertion The ball screw shaft 2 is rotated while the azimuth is determined, and the gripper 3 is lowered to insert the fuel into the core. (6) Fuel release As shown in FIG. 6 (A), the spline 6 is reversed to rotate the arm 4a to the position shown by the solid line in FIG. 6 (B), and the gripper claw opening / closing mechanism 4 connected to the arm 4 is moved to the position shown in FIG. (C)
, Pull up the claw opening / closing rod 8 connected to the gripper claw opening / closing mechanism 4 to close the gripper claw 7,
Disengage the fuel from the gripper pawl 7. At this time, the spline 6 is reversed to the position indicated by the solid line, and the mesh between the gripper rotating gear 5 and the gripper gear 3a is disengaged. (7) Ascent The ball screw shaft 2 is reversed and the gripper 3 is raised. In this way, the fuel can be inserted into the core at a predetermined position.

[0012]

According to the present invention, the arm of the gripper claw opening / closing mechanism is engaged with the engagement member of the spline with a margin angle, and the gripper opens the pawl even if the spline is rotated by the margin angle, and the gripper opens the fuel. It is still in the state of holding. At this time, the gripper can be rotated by further rotating the spline, the fuel insertion position can be determined, and the fuel self-orientation can be backed up.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a fuel exchanger gripper according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the gripper opening / closing mechanism of FIG.

FIG. 3 is a view on arrow III in FIG.

4A and 4B are explanatory views showing a fuel gripping operation of the fuel exchanger gripper of the present invention, FIG. 4A is a view showing the movement of the spline, and FIG. 4B is a plan view showing the movement of the gripper claw opening / closing mechanism.
(C) is a front view showing the movement of the gripper opening / closing mechanism, (D)
FIG. 6 is a diagram showing the movement of a gripper rotating gear.

FIG. 5 is an explanatory diagram showing an orientation determining operation of the fuel exchanger gripper of the present invention, (A) showing a movement of a spline,
(B) is a plan view showing the movement of the gripper claw opening / closing mechanism,
(C) is a front view showing the movement of the gripper opening / closing mechanism, (D)
FIG. 6 is a diagram showing the movement of a gripper rotating gear.

FIG. 6 is an explanatory view showing a fuel release operation of the fuel exchanger gripper of the present invention, (A) showing a movement of a spline,
(B) is a plan view showing the movement of the gripper claw opening / closing mechanism,
(C) is a front view showing the movement of the gripper opening / closing mechanism, (D)
FIG. 6 is a diagram showing the movement of a gripper rotating gear.

FIG. 7 is a block diagram of a conventional fast breeder reactor fuel exchanger,
(A) is a longitudinal sectional view, (B) is a BB sectional view of (A).

8 is a configuration diagram of the telescopic arm type fuel exchanger of FIG.

[Explanation of symbols]

 1 Support Member 2 Pole Screw Shaft 3 Gripper 3a Gripper Gear 4 Gripper Claw Opening / Closing Mechanism 5 Gripper Rotating Gear 6 Spline 6a Engaging Member 7 Gripper Claw 8 Claw Opening / Closing Rod 9 Telescopic Arm Fuel Exchanger

Claims (1)

[Claims] 1. A support member coupled to a ball screw shaft, and a gripper supported by the support member and having a gripper claw,
A spline attached to the support member, a gripper claw opening / closing mechanism connected to an engaging member at an upper portion of the spline via an arm, and an opening / closing rod connected to the gripper claw opening / closing mechanism, the liquid metal In the fuel exchanger of the fast breeder reactor as a coolant, the arm is engaged with the engaging member at a predetermined margin angle,
A fan-shaped gripper rotating gear attached to the lower portion of the spline, a gripper gear that meshes with the gripper rotating gear, and a bearing that is attached to the support member and rotatably supports the gripper are provided, and the margin angle is set. A fuel exchanger gripper for a fast breeder reactor, wherein the gripper rotating gear and the gripper gear are engaged with each other to rotate the gripper when the spline is rotated over.