JPH0222359B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

This invention relates to reactor fuel handling equipment for pressure tube nuclear reactors, and in particular to a collector installed in a fuel exchange machine for attaching and detaching a collect joint that connects a fuel assembly and a shield plug during fuel exchange. Regarding a joint attachment/detachment device.

[Prior art and its problems]

First, Figure 3 shows an overview of the fuel exchange equipment for a pressure tube reactor. In the figure, 1 is a reactor core, 2 is a pressure pipe that constitutes the reactor core, and inside the pressure pipe 2, a fuel assembly 3, a seal plug 4, and a seal plug 5 are loaded in order. Hei plug 4
are removably connected to each other via a collet joint, which will be described later. On the other hand, the fuel exchange of the core is performed by a fuel exchanger 6 running below the core 1. As is well known, this fuel exchanger has a grab mechanism, magazine mechanism, etc. built into its pressure vessel, and after connecting the fuel exchanger 6 to the pressure pipe 2, the fuel assembly is assembled by operating the grab mechanism. , pulling out and loading seal plugs, seal plugs, etc. Here, the structure of the above-mentioned collet joint is shown in FIGS. 4 and 5. The collet joint 7 consists of a tie plate 8 attached to the lower end of the fuel assembly 3 and a collet section attached to the upper end of the shielding plug 4. 9, and the collet portion 9 has, at its upper end, comb-like pawl pieces 9a arranged in the circumferential direction that form pawls that engage with engagement grooves on the inner circumferential surface of the tap plate 8. With this configuration, in order to separate the collet joint 7, first apply force from the outer circumferential side of the collet part 9 as shown by arrow F, and squeeze each claw piece 9a of the collet part inward as shown by the chain line to separate the claws. Then, the fuel assembly 3 is pulled upward or pulled down below the damper plug 4 to separate the two. Conversely, when connecting the stiffening plug 4 to the fuel assembly 3, apply force to the claw pieces 9a of the collector part 9 from the outer circumferential side to squeeze them in the same manner as described above, and then insert the collector part into the tie plate. When the force is released later, the claw piece of the collet part elastically returns to its original state and engages with the engagement groove on the tie plate side, thereby connecting the two. By the way, in the past, the work of separating the spent fuel fuel assembly 3 and the hardening plug 4 during refueling, or connecting the new fuel fuel assembly and the hardening plug with the hardening plug, was performed when the fuel changing machine and the fuel changing pool were connected. A collet joint attachment/detachment device is installed in the transfer port between the two, and the above-mentioned collet joint attachment/detachment device is used to suspend the fuel assembly between the fuel assembly and the transfer port using the fuel exchange machine. Here, the structure of a conventional collet joint attachment/detachment device is shown in FIGS. 6 and 7. Reference numeral 10 denotes a base with a passage hole 10a opening in the center for guiding the elevation and descent of core components such as fuel assemblies and shield plugs. The rotary ring 11 is slidably supported by a support member 12 provided in the rotary ring 11.
On the diagonal line is an operating cylinder 1 as a driving means.
3a and 13b are connected via an operating shaft 14. On the other hand, on the circumference of the rotating ring, there are 8 screws, the same number as the claws on the collector part, with the tips facing the passage hole 10a.
The rear end portions of the collect aperture claws 15 are pivotally connected to each other by pins, and the long groove-shaped cam grooves 15a formed in each aperture claw 15 are provided with fixing devices arranged side by side on the inner circumferential side of the rotating ring 11. It fits into the guide pin 16 on the side and is guided and supported. With this structure, by driving and operating the operation cylinders 13a and 13b in opposite directions, the rotating ring 11 rotates in the circumferential direction, and the collect aperture pawl 15 is guided by the guide pin 16 and rotates as shown by arrow A. Then, the robot is operated forward and backward toward the passage hole 10a. Therefore, when attaching and detaching the collet joint, the collet described in FIG.
When the fuel assembly is inserted into A, the tips of the collection squeezing claws 15 are pressed from the outer periphery to the collect part by operating the operation cylinder, so that the claw pieces of the collection part are pushed into the inner periphery, and in this state, the fuel assembly is The collet joints will be connected and separated by lifting and lowering operations using the loading and unloading machine. On the other hand, recently, with the aim of shortening the work time during fuel exchange and downsizing the fuel exchange machine, the above-mentioned collet joint attachment/detachment device has been installed at the upper end of the fuel exchange machine, and it is possible to connect the fuel assembly to the hard plug. A system has been proposed in which the coupling and separation operations are carried out in parallel with the loading and unloading of fuel assemblies into the core, and the fuel assemblies and plugs are housed separately in magazines in the pressure vessel of the fuel exchanger. ing. However, in this case, if the above-mentioned collet joint attachment/detachment device is installed and used as is in the fuel exchanger, the following problems will occur. In other words, in the conventional fuel exchange method, when attaching or detaching the collet joint, a heat plug is set in the collet joint attaching/detaching device, and the fuel assembly is moved up and down while the collet section is kept in a constricted state to couple and separate the two. However, when installing the collet joint in a refueling machine and attaching and detaching it in parallel with the refueling operation, it is necessary to insert a part of the fuel assembly into the pressure pipe on the core side due to the refueling procedure. It is necessary to connect and disconnect the collet joint by lifting and lowering the stiff plug using a grab mechanism while leaving the plug in place. However, when the flexible plug is raised and lowered with the collector part of the flexible plug squeezed by the collet joint attachment/detachment device, if the conventional structure is used, the collet part will be rubbed by the collet squeeze pawl 15 of the collet joint attachment/detachment device and be damaged. Otherwise, the collection claw may be damaged by the vertical moment load. Furthermore, since the structure is such that a guide pin 16 is provided on the inner peripheral side of the rotating ring 11 and the guide pin controls the movement of the collect drawing claw 15 in the radial direction, the radial dimension is large. Nari Space Factor is also bad. In addition, foreign matter such as crud and sludge enters the pressure vessel of the fuel exchanger from the pressure tube side of the reactor core, but in the conventional structure, the top is open and there are many mechanically sliding parts. This foreign matter accumulates in the collet joint attachment/detachment device, and in particular enters its sliding portion, causing galling, making it difficult to maintain its integrity.

[Purpose of the invention]

This invention was made in consideration of the above points, and its purpose is to improve the conventional device, reduce the number of sliding parts and parts in the device, and provide a compact and highly reliable collet joint attachment/detachment device. Our goal is to provide the following.

[Key points of the invention]

In order to achieve the above object, the present invention includes an annular housing having a guide passage hole opening in the center through which core components such as fuel assemblies and shield plugs pass; a rotary cam rotatably supported by a bearing and having diagonal cam grooves distributed around the circumference of one end surface thereof; a rotation driving means for the rotary cam; The housing is guided and supported in the direction, and its guide pin is engaged in a cam groove of the rotary cam, so that the tip of the housing moves in and out of the guide passage hole in a radial direction as a result of rotation of the rotary cam. It consists of a collector aperture push rod with a tip guide roller housed inside the collector.

[Embodiments of the invention]

FIGS. 1 and 2 show a cross-sectional view and a vertical cross-sectional view of a collet joint attachment/detachment device according to an embodiment of the present invention, which has a guide passage hole 17a opened in the center through which core components pass. Annular housing 1
7, a rotary cam 19 rotatably supported within the housing via a bearing 18, a push rod 20 whose movement is controlled by the rotary cam also supported within the housing, and a drive section of the rotary cam. It is constructed as an assembly. Of these, the rotary cam 19 has diagonal cam grooves 19a distributed and lined up on the circumference of its upper end surface, and is connected diagonally to operating cylinders 13a and 13b as drive units via an operating shaft 14. ing. On the other hand, the push rod 20 includes a rod main body 20a that is evenly distributed around the circumference of the housing 17 and guided and supported in the radial direction, a guide roller 20b that comes into contact with a collet attached to the inner end of the rod main body, and a rod main body It consists of a guide pin 20c with a roller that protrudes downward from a midway point and fits into the cam groove 19a. With the above configuration, if the rotary cam 19 is rotated in the circumferential direction within the housing 17 by driving the operation cylinders 13a and 13b, the push rod 20
is driven by the rotary cam and moves linearly in the radial direction under the control of its cam groove 19a, and the guide roller 20b at the tip moves forward and backward toward the central passage hole 17a in accordance with the rotating direction of the rotary cam. will be manipulated. Therefore, when attaching or detaching the collet joint, the guide roller 20 of each push rod 20 can be removed by inserting and setting the collet portion on the side of the plug into the passage hole 17a of the housing 17 and performing the above operation in this state.
b comes into contact with the comb-like pawls of the collet shown in FIGS. 4 and 5, and the pawls of the collet are squeezed and released. In addition, when lifting or lowering the flexible plug with the collet section pressed and its claws squeezed, the guide roller is in contact with the outer periphery of the collet section, so the sliding resistance is small and the fuel assembly Separation and connection between the plug and the plug can be performed smoothly. Further, according to the above structure, the rotary cam 19,
Both push rods 20 are housed within the housing 17, so when they are installed and used in a fuel exchange machine, even if foreign matter such as crud or sludge settles and enters the fuel exchange machine from the core side, they will not be damaged. There is a low probability that these foreign substances will accumulate on the bearing support of the rotary cam and push rod in the housing and cause galling, and reliability can be improved compared to the conventional structure. Further, since the rotary cam 19 is configured to directly control the linear motion of the push rod 20, the number of parts is reduced compared to the conventional structure, and the radial dimension in particular can be reduced to make the structure smaller and more compact.

【Effect of the invention】

As described above, according to the present invention, the annular housing has a guide passage hole opened in the center through which core components such as fuel assemblies and shield plugs pass;
A rotary cam housed in the housing and rotatably supported by a bearing in the circumferential direction of the housing, and having diagonal cam grooves distributed over the circumference of one end surface thereof, and a rotation driving means for the rotary cam. The guide pins are distributed in the circumferential direction of the housing and guided and supported in the radial direction, and the guide pins thereof are engaged in the cam grooves of the rotary cam, and the tips of the rotary cams are driven by the rotation of the rotary cam and the tips thereof are inserted into the guide passage holes. This construction consists of a collector throttling push rod with a guide roller at the tip, which is housed in the housing so that it moves in and out in the radial direction toward the fuel exchanger. As a collet joint attachment/detachment device for attaching/detaching the coupling, it is less affected by crud that enters the fuel exchanger from the core side, and is flexible with a grab mechanism. It is possible to provide a collet joint attachment/detachment device with high practical value, such as smooth connection and separation between the two, and a small and compact structure.

[Brief explanation of drawings]

1 and 2 are a cross-sectional view and a longitudinal sectional view of a collet joint attachment/detachment device showing the configuration of an embodiment of the present invention, respectively, FIG. 3 is a schematic diagram of a fuel exchange facility for a pressure tube reactor, and FIG. 5 are a longitudinal cross-sectional view and a cross-sectional view taken in the direction of the arrows in FIG. 4, respectively, showing the structure of a collet joint, and FIGS. FIG. 1: Reactor core, 3: Fuel assembly, 4: Shiyahei plug, 6: Fuel exchanger, 7: Collet joint,
8: Tie plate, 9: Collet part, 13a, 1
3b: operation cylinder as driving means, 17: housing, 17a: guide passage hole of housing component, 18: bearing of rotary cam, 19: rotary cam, 19a: cam groove of rotary cam, 27:
Push rod, 20b: Guide roller, 20
c: Guide pin.

Claims (1)

[Scope of Claims] 1. An attachment/detachment device for a collet joint that connects a fuel assembly and a shielding plug, which has a guide passage hole in the center through which core components such as the fuel assembly and shielding plug pass. an annular housing with an opening; a rotary cam that is housed within the housing and supported by a bearing so as to be rotatable in the circumferential direction of the housing, and that has oblique cam grooves distributed over the circumference of one end surface thereof; The rotation driving means of the rotary cam is distributed in the circumferential direction of the housing and guided and supported in the radial direction, and its guide pins are engaged in the cam grooves of the rotary cam to follow the rotation of the rotary cam. A collector joint attachment/detachment for reactor fuel, characterized in that it is comprised of a collector throttle push rod with a guide roller at the tip housed in a housing so that the tip moves in and out of the guide passage hole in a radial direction. Device 2 In the collet joint attachment/detachment device according to claim 1, the collet joint attachment/detachment device is installed in a fuel exchange machine, and at that location, the collet joint between the fuel assembly and the flexible plug is installed during fuel exchange. 1. A reactor fuel collet joint disconnection device, characterized in that it performs attachment/detachment operations.