JPS6032153B2 - Gripper for fuel loading/unloading machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel loading/unloading machine for loading and unloading fuel assemblies for nuclear reactors, particularly fast breeder reactors that use liquid metal sodium as the primary coolant, from the nuclear reactor and transferring them to fuel storage equipment. Regarding preferred grippers.

The gripper of the fuel loading/unloading machine that handles the fuel assemblies for the fast breeder reactor mentioned above is suspended with high tensile strength stainless steel tape, and this tape is wrapped around it to make it easier to scrape off adhering sodium and clean it. By driving the winding drum, the entire gripper is raised and lowered, and the gripper claws are opened and closed. On the other hand, if the fuel were to drop or become stagnant during fuel transfer, it would immediately cause a serious problem in the operation of the reactor, so extremely high reliability is required. Ru. Further, the fuel assembly is transferred between the nuclear reactor and the fuel storage facility while being accommodated in a fuel transfer pot filled with sodium, and from the fuel storage facility, the fuel assembly is transferred as is. From these points, it is desirable that the following requirements be met for fuel inlet/output machines. In other words, even if one of the tapes suspending the gripper breaks, the fuel will not fall and the subsequent operation can be performed without any problem, and the fuel assembly, which is the object to be handled, will be prevented from falling. Since the shape and dimensions of the handling head of the body and fuel transfer pot differ, it is necessary to replace the gripper tip with a gripper tip that matches the shape and dimensions of the object to be handled each time, but the replacement work can be done easily and quickly. . In addition, high reliability can be obtained in terms of safety and operability. By the way, a basic structure system in which the gripper is suspended by a pair (two tapes) to raise and lower the gripper and open and close the claws has already been put into practical use and has achieved stable operation results. In addition, in order to safely support the fuel without dropping it even if one of the tapes breaks, two pairs of grippers (four grippers) are installed in advance.
If one tape breaks, the load is immediately supported by the remaining healthy pair of tapes, and two pairs of tapes are used to suspend the gripper. Improvements have been proposed that would allow for emergency disconnection of the gripper and fuel even if one of the tapes becomes inoperable, but these existing proposals are complex and far removed from the basic structure that has been used in operation. It has a very similar structure, and there are considerable problems in proving its high reliability in actual commercialization. In addition, when changing the object to be handled by the fuel loading/unloading machine from transferring a single fuel assembly to transferring a fuel transfer pot, or vice versa, each time the gripper tip is changed to a different one with a different shape and size. However, in the conventional method, the fuel inlet/output machine is moved to a maintenance area, the gripper is cleaned there, and then "a worker must approach and replace the gripper tip directly by hand." First, there remain the problems of maximizing the time required for replacement work and safety against radiation exposure of workers. By cleverly combining the basic mechanical parts used in proven grippers, we are able to safely maintain fuel suspension even if any tape breaks, and ensure fuel disconnection in an emergency. Go,
Furthermore, the tip of the gripper can be replaced according to the type of object to be handled remotely by simply operating the hanging tape, which saves the work of cleaning the sodium each time, simplifying and speeding up the replacement work. It is an object of the present invention to provide an advantageous gripper that allows for easy gripping. Hereinafter, embodiments of the present invention for achieving the above object will be described in detail based on illustrated embodiments.

First, in FIG. 1, 1 is the gripper upper base, 2 is the gripper tip body that fits the fuel transfer pot, 2' is the gripper tip body that fits the fuel assembly, and 3 and 3' are the fuel transfer pot and fuel, respectively. This figure shows the handling head at the upper end of the assembly, and in particular, the lower left half of the figure is the tip body 2', and the right half is the one where the tip body 2 is attached and which handles the object 3.
, 3' is shown. The basic structure of the gripper according to the present invention consists of the above-described combination of the gripper upper base body 1 and the gripper tip body 2 or 2'.

The upper base 1 has two sets of drums 5 and 6 mounted vertically in a cylindrical casing 4. As clearly shown in the cross-sectional views of FIGS. 2 and 3, each paper drum 5, 6 consists of two rows of drums supported by bearings 7 fixed to the casing 4. 5 and S, respectively, two pairs of independent hanging tapes 8
and 8' and 9 and 9' are wound and connected. Furthermore, a plurality of intermediate connecting pawls 10 are installed in the lower end castle in the casing 4 via pins 11 in a manner that they are aligned in the circumferential direction and the tips of the pawls protrude from the outer periphery of the casing.
An actuator 12 for opening and closing the pawl located opposite the intermediate connecting pawl 1 is connected to one of the drums 5 through a crankshaft 13. The claw opening/closing operation mechanism composed of the drum 5, tapes 8, 8', crankshaft 13, actuator 12, and claw 10 is similar to the claw opening/closing mechanism currently used in grippers with a proven track record. By operating 8 and 8' in opposite directions, the drum 5 is rotated, and the crankshaft 13 is rotated accordingly.
moves the actuator 12 up and down to open and close the claw 10. Further, a gripper claw opening/closing actuator 15, which will be described later, is connected to the other drum 6 via a crankshaft 14 that projects downward from the upper base 1. On the other hand, the gripper tip bodies 2 and 2' each have a cylindrical claw holder 16,
16' is provided with gripper claws 17, 17' that are opened and closed by the operation of the actuator 15, and the upper ends of the claw holders 16, 16' are fitted into the lower end of the gripper upper base 1 in a cast-in type manner. is formed as a handling head that engages with the intermediate connecting pawl 18, and its lower tip is shaped to match the size and shape of the handling head of the fuel assembly 3' without the fuel transfer pot 3. In addition, the gripper claws 17, 17' are attached to the pins 18, 17' in the claw holders 6, 16' in the same way as the intermediate connecting claws 10 described above.
18', and is swingably installed so that the tips of the claws protrude laterally from the tips of the claw holders 16, 16'. Thus, in the fuel transfer pot tip body 2, the gripper claw 17 directly faces the actuator 15, whereas in the small diameter fuel assembly tip body 2', the gripper claw 17 directly faces the actuator 15.
An intermediate lever 19' and an operating lever 20' are interlocked with each other, and the operating lever 20' is located opposite to the actuator ]5. Therefore, by operating the hanging tapes 9 and 9' in opposite directions for each of the tip bodies 2 and 2', the drum 6 rotates and moves the actuator 15 up and down, which is interlocked with this operation. Then, without the gripper claw 17, the gripper 17' is opened and closed. Furthermore, the gripper tip body 2, 2
The handling head at the upper end of the claw holders 6, 16' in the gripper claws 17, 17' is arranged at a pitch interval corresponding to the vertical movement stroke of the actuator 15 for opening and closing the gripper claws 17, 17'. Engagement grooves 21, 22, 21', 22' are formed. By the way, as shown in FIG. 4, each pair of hanging tapes 8, 8'9 connected to the built-in drums 5, 6 of the gripper upper base 1
, 9' are individually wound around take-up drums 24, 25, 26, 27 installed in a take-up drum case 23 installed in a take-up drum case 23 mounted on a fuel inlet/output machine at the upper side. There is. Further, the drum shafts of each of the winding drums 24 to 27 are connected to a drive mechanism 28. The drive mechanism 28 is composed of a motor 29, a reduction gear 30, and a mechanism in which a clutch and an interlocking gear train shown in dotted lines 31 are combined, and a mechanism that interlocks or interlocks each winding drum 24 to 27 based on an operation command. Rotationally driven individually. Next, the operation of the gripper will be described.

First, the fuel transfer pot 3 and the fuel assembly 3 are handled as objects to be handled.
The gripper tip body is selected depending on which one of the two parts is to be transferred. That is, in the former case, the tip body 2 for the fuel transfer pot is used, and in the latter case, the tip body 2' for the fuel assembly is used.
is selected, and after suspending the gripper upper base 1 from above and fitting it into the handling head of the tip body, the intermediate connecting claw 10 is engaged with the lower engagement groove 22 or 22' of the tip body to connect the two. do. The situation at this time is described in Chapter 5.
As shown in the figure. Note that the gripper upper base 1 has four tapes 8,
8', 9, and 9', and in order to move the upper base 1 up and down, the respective winding drums 24 to 27 are simultaneously connected to wind up each tape and then drive it down. Further, in order to open and close the intermediate connecting claw 10, the winding drums 26 and 27
By rotating the winding drums 24 and 25 in opposite directions while the tapes 8 and 8' are stopped and locked, the drum 5 is rotated by the relative movement of the tapes 8 and 8', and the intermediate connecting claw 10 is opened and closed. . Now, with the gripper tip body 2 or 2' connected to the upper base body 1, the fuel injector is moved to a predetermined fuel handling position, where the entire gripper is suspended above the object to be handled. Next, by driving the winding drums 26 and 27 in opposite directions while keeping the winding drums 24 and 25 stopped and locked, the drum 6 is rotated by operating the tapes 9 and 9', and the gripper claw 17 is removed and the gripper claw 17 is removed. ' to engage the object to be handled. After that, the object to be handled is lifted and lowered to a predetermined handling position by lifting and lowering the entire gripper and moving the fuel inlet/output machine while gripping the object, and then the gripper claw is released.
The first fuel transfer is completed. By the way, even if one of the tapes 8, 8', 9, and 9' breaks during fuel transfer, the hanging load will be supported by the remaining pair of healthy tapes. , the gripper does not fall, and the transfer of the object to be handled can be continued without any stagnation. Further, if the broken tape is either tape 8 or 8', there is no problem in opening and closing the gripper claws 17 or 17', and the object to be handled can be cut. Furthermore, a major feature of the present invention is that the gripper tip body can be changed from 2 to 2' or from 2' to 2 in response to changing the handled object from a fuel transfer pot to a fuel assembly or vice versa. In this case, the operation of opening and closing the intermediate connecting claw 10 by rotating the drum 5 and
In combination with the lifting and lowering movement operation, replacement work can be performed remotely.

As a result, there is no need for workers to approach the gripper to perform replacement work as in the past, and the process of cleaning the gripper, which was performed in consideration of radiation exposure, can also be omitted.
Replacement work time can be significantly shortened. As is clear from the above description, the present invention satisfies all of the above functional conditions required of a gripper, and provides various functions such as ensuring safety in the event of tape breakage and replacing the gripper tip body by remote control. In addition, the mechanical parts of each part that make up the gripper can be used as is, with the same structure as the mechanical parts of the gripper whose reliability has been proven through actual operation results. A gripper with excellent reliability can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS Each figure shows an embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view in a normal operating state, and FIGS. 4 is a drive system diagram of the gripper, and FIG. 5 is a longitudinal sectional view showing a separated state of the gripper upper base body and tip body.

DESCRIPTION OF SYMBOLS 1...Gripper upper base body, 2...Gripper tip body, 4...Casing, 5, 6 drums, 8, 8'9, 9'...Hanging tape, 10...Intermediate connecting claw, I2, 15...Actuator, 13, 14 ...Crank track, 16, 16'... Pawl holder, 17, 17'... Gripper pawl, 21, 21', 22, 2
2'...Handling engagement groove.

Ushio “Figure” 2nd figure force 3 diagram talent map 5th figure

Claims (1)

[Claims] 1. Two sets of drums each operated independently by a pair of hanging tapes are mounted in a casing, and the upper base of the gripper has intermediate connecting claws protruding to the outer periphery at the lower end of the casing, and the tip part is handled by the handler. a gripper tip body which is provided with gripper claws in a claw holder shaped to match the dimensions of the handling head of the object and is suspended and connected to the gripper upper base via the intermediate connecting claws; It consists of an actuator for operating intermediate connecting claws or an actuator for operating gripper claws connected via a crankshaft, and by operating the hanging tape, the gripper can be raised and lowered, connected to and separated from the object to be handled, and the upper base of the gripper A gripper for a fuel inlet/outlet machine, characterized in that the gripper is configured to connect and disconnect between the and the tip body.