JP5675448B2 - Fuel rod changer - Google Patents

Description

  The present invention relates to a fuel rod exchange device for exchanging fuel rods between a reactor core and a storage chamber.

  An example of a fuel rod exchange device for exchanging fuel rods between the reactor core and the storage chamber is shown in FIGS.

  As shown in FIGS. 5 and 6, a ball whose axial direction is directed upward and downward is located above the interior of the hollow body 11 having an opening on the front (left side in FIGS. One end side of the screw shaft 12 is rotatably attached. A support plate 13 is screwed onto the ball screw shaft 12 so that the support plate 13 can move along the ball screw shaft 12 as the ball screw shaft 12 rotates. It has become.

  One end (upper end) of the drive shaft 14 whose axial direction is directed up and down is connected and fixed to the lower surface of the support plate 13. The other end (lower end) of the drive shaft 14 is connected and fixed to the upper surface of an inner hollow movable cylinder 15 having an opening in the front (left side in FIGS. 5 and 6) and the lower surface with the axial direction facing up and down. The movable cylinder 15 can move up and down in the main body drum 11 via the support plate 13 and the drive shaft 14 as the ball screw shaft 12 rotates.

  Inside the movable cylinder 15, an internal hollow storage case 16 having an opening on the lower surface with the axial direction facing up and down is disposed. Above the inner wall surface of the movable cylinder 15, the base end side of the upper arm 17 is connected to the inside and outside of the movable cylinder 15 and the main body cylinder 11 through the opening of the movable cylinder 15 and the main body cylinder 11. It is connected so as to be rotatable about a horizontal axis so as to enable the swing movement of the front end side between them. The distal end side of the upper arm 17 is connected to the middle of the outer wall surface of the storage case 16 so as to be rotatable about the same horizontal axis as the base end side.

  In the middle in the vertical direction of the inner wall surface of the movable cylinder 15, the base end side of the lower arm 18 is connected to the inside of the movable cylinder 15 and the main body cylinder 11 through the opening of the movable cylinder 15 and the main body cylinder 11. It is connected so as to be rotatable about a horizontal axis so as to enable a swing movement on the tip side with the outside. The distal end side of the lower arm 18 is connected to the lower side of the outer wall surface of the storage case 16 so as to be rotatable about the same horizontal axis as the base end side.

  Below the inside of the main body cylinder 11, the base end side of the link arm 19 is between the inside and outside of the movable cylinder 15 and the main body cylinder 11 via the opening of the movable cylinder 15 and the main body cylinder 11. It is connected and supported so as to be pivotable about a horizontal axis so that the tip side can be swung. The distal end side of the link arm 19 is connected between the proximal end and the distal end of the lower arm 18 so as to be rotatable about the same horizontal axis as the proximal end side.

  In other words, when the ball screw shaft 12 is rotated to lower the movable cylinder 15 via the support plate 13 and the drive shaft 14, the storage case 16 is moved by the action of the arms 17 to 19. 15 and the main body drum 11 so as to swing from the inside to the outside (see FIG. 6), and the ball screw shaft 12 is rotated to move the movable cylinder 15 via the support plate 13 and the drive shaft 14. Is raised, the storage case 16 swings and moves so as to be located from the outside to the inside of the movable cylinder 15 and the main body cylinder 11 by the action of the arms 17 to 19 (see FIG. 5). -ing

  Inside the storage case 16, a guide rail 20 having a longitudinal direction directed upward and downward is attached. The guide rail 20 is provided with a gripper device 21 that detachably holds a fuel rod so as to move along the guide rail 20.

  The main body cylinder 11 is disposed so as to be movable along the circumferential direction of the core above the core in the reactor, and is rotatable in the circumferential direction so that the direction of the front side can be switched. ing. 5 and 6, reference numeral 22 denotes a drive motor that rotates the ball screw shaft 12.

  In such a pantograph type fuel rod exchanging device 10, when exchanging fuel rods, the main body cylinder 11 is positioned so as to be closest to the intended spent fuel rod in the core. After the main body cylinder 11 is moved along the circumferential direction of the core, the arms 17 to 19 are swung to swing the storage case 16 from the inside of the movable cylinder 15 and the main body cylinder 11 to the outside. Thus, the drive motor 22 is operated so that the gripper device 21 is positioned above the intended used fuel rod, and the movable cylinder 15 is lowered through the drive shaft 14 for a predetermined length.

  Then, when the gripper device 21 is lowered along the guide rail 20 and the upper part of the intended used fuel rod is gripped by the gripper device 21, the gripper device 21 is raised along the guide rail 20. As a result, after the fuel rod is stored in the storage case 16, the arms 17 to 19 are swung to swing the storage case 16 from the outside to the inside of the movable cylinder 15 and the main body cylinder 11. As a result, the drive motor 22 is operated so as to store the storage case 16 in the movable cylinder 15, and the movable cylinder 15 is raised to a predetermined upper position via the drive shaft 14. .

  Subsequently, when the main body cylinder 11 is moved along the circumferential direction of the core so as to be positioned in the vicinity of the storage chamber, the drive motor 22 is operated to move the movable cylinder 15 to a predetermined position via the drive shaft 14. By lowering the arm 17-19, the arms 17-19 are swung to place the spent fuel rods stored in the storage case 16 above the storage chamber, and then the gripper device 21 is lowered to The fuel rod is stored in the storage chamber.

  Next, when a new fuel rod in the storage chamber is gripped by the gripper device 21, the gripper device 21 is raised and the fuel rod is stored in the storage case 16, the storage case 16 is moved to the movable cylinder 15. The drive motor 22 is operated so as to be housed inside, and the movable cylinder 15 is raised to a predetermined upper position via the drive shaft 14, and then the main body cylinder 11 is moved in the circumferential direction of the core. The movable cylinder 15 is lowered by a predetermined length via the drive shaft 14 by moving the drive motor 22 again, and above the location where the previously extracted fuel rod is located. After the new fuel rod stored in the storage case 16 is positioned, the gripper device 21 is lowered and the new fuel rod is put into the reactor core.

  By performing such an operation, the fuel rods are exchanged between the core and the storage chamber.

Japanese Patent Laid-Open No. 63-214697 Japanese Patent Application Laid-Open No. 07-181153

KATOH Atsushi, CHIKAZAWA Yoshitaka, OBATA Hiroyuki, KOTAKE Shoji, "Development of Advanced Fuel Handling Machine for JSFR", Journal of Nuclear Science and Technology, Vol.47, No.7, p.642-651 (2010)

  In the fuel rod exchanging device 10 as described above, the lower side where the fuel rod is handled is located in the sodium melt 1 (about 200 ° C.) in the furnace, and the upper side is inside the furnace because of the positional relationship in the furnace. Is located in the atmosphere of the cover gas 2 (about 150 ° C.), the drive shaft 14 is moved when the movable cylinder 15 is raised so that the storage case 16 is positioned inside the movable cylinder 15. Is positioned on the cover gas 2 side over the entire length (see FIG. 5), but when the movable cylinder 15 is lowered so that the storage case 16 is positioned outside the movable cylinder 15, the lower side of the drive shaft 14 is It comes to be located in the sodium melt 1 side (refer FIG. 6).

  For this reason, a difference in thermal expansion occurs in the drive shaft 14 between when the movable cylinder 15 is raised and when it is lowered, and the positioning accuracy of the gripper device 21 with respect to the target fuel rod is reduced. I have been invited.

  In view of the above, an object of the present invention is to provide a fuel rod exchanging device that can prevent a decrease in positioning accuracy due to thermal elongation of a drive shaft.

A fuel rod exchanging device according to a first aspect of the present invention for solving the above-described problem is an internal hollow main body cylinder having an opening at the front face, which is arranged so that its longitudinal direction is directed up and down, and its longitudinal direction up and down. An internal hollow movable cylinder that is disposed inside the main body body and has an opening on the front surface thereof, a drive shaft having a lower end coupled to the movable cylinder, and a support member coupled to an upper end of the drive shaft. An elevating / moving means for supporting the supporting member to move the movable cylinder up and down inside the body barrel, and an interior having an opening on the lower surface disposed in the movable cylinder so that the longitudinal direction thereof is directed up and down A hollow storage case, a fuel rod holding means that is detachably disposed inside the storage case and that removably holds a fuel rod, and the movable cylinder via the opening of the movable cylinder and the main body cylinder And inside and outside of the main body Swing support means for supporting the storage case so that it can swing and move, and as the movable cylinder is lowered, the storage case is positioned outside the movable cylinder and the main body body and the movable cylinder is raised. Accordingly, swinging means for swinging the storage case so that the storage case is positioned inside the movable cylinder and the main body barrel, and linear expansion different from the drive shaft are connected to the lower end of the movable cylinder. An index shaft having a rate, a displacement amount measuring means for measuring a displacement amount of the upper end side of the index shaft with respect to the support member, and a thermal elongation amount of the drive shaft is calculated based on information from the displacement amount measuring means And an arithmetic and control unit that corrects the amount of vertical movement of the movable cylinder by the vertical movement unit corresponding to the amount of thermal expansion.

  A fuel rod exchanging device according to a second invention is the fuel rod exchanging apparatus according to the first invention, wherein the displacement measuring means is an output worm provided on the upper end side of the indicator shaft and a large-diameter worm meshed with the output worm. A small-diameter worm wheel that meshes with the large-diameter worm wheel and has a smaller number of teeth than the large-diameter worm wheel, an input worm that is movably supported in the axial direction and meshes with the small-diameter worm wheel, and the input worm And a movement amount measuring means provided on the support member for measuring the movement amount of the detection member.

  According to the fuel rod exchanging device according to the present invention, when a difference in thermal elongation occurs between the drive shaft when the movable cylinder is raised and when it is lowered, the thermal elongation amount different from the thermal elongation amount of the drive shaft. Thus, when the index axis produces a difference in thermal expansion, the displacement amount measuring means measures the displacement amount on the upper end side of the index axis with respect to the support member, and the arithmetic control means is based on the information from the displacement amount measuring means. Since the amount of thermal extension of the drive shaft is calculated and the amount of up and down movement of the movable cylinder by the up-and-down moving means is corrected corresponding to the amount of thermal extension, it is possible to prevent a decrease in positioning accuracy due to the thermal extension of the drive shaft. .

It is a schematic block diagram of the principal part of main embodiment of the fuel rod exchange apparatus which concerns on this invention. It is explanatory drawing of the operation state at the time of the fuel rod replacement | exchange of the fuel rod replacement | exchange apparatus of FIG. It is an extraction enlarged view inside the arrow III part of FIGS. It is a control block diagram of the principal part of the fuel rod exchange apparatus of FIG. It is a schematic block diagram of the principal part of an example of the conventional fuel rod exchange apparatus. It is explanatory drawing of the operation state at the time of the fuel rod replacement | exchange of the fuel rod replacement | exchange apparatus of FIG.

  Embodiments of a fuel rod exchanging apparatus according to the present invention will be described with reference to the drawings, but the present invention is not limited to only the following embodiments described with reference to the drawings.

[Main embodiments]
A main embodiment of a fuel rod exchange device according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, a ball whose axial direction is directed upward and downward is located above the interior of the hollow body body 111 having an opening on the front (left side in FIGS. One end side of the screw shaft 112 is rotatably attached. A support plate 113 that is a support member is screwed onto the ball screw shaft 112, and the support plate 113 moves along the ball screw shaft 112 as the ball screw shaft 112 rotates. Can be done.

  One end (upper end) of the drive shaft 114 is connected and fixed to the lower surface of the support plate 113 with the axial direction directed up and down. The other end (lower end) of the drive shaft 114 is connected and fixed to the upper surface of an inner hollow movable cylinder 115 having openings in the front (left side in FIGS. 1 and 2) and the lower surface with the axial direction facing up and down. The movable cylinder 115 can move up and down in the main body drum 111 via the support plate 113 and the drive shaft 114 as the ball screw shaft 112 rotates.

  Inside the movable cylinder 115, an internal hollow storage case 116 having an opening in the lower surface with the axial direction facing up and down is disposed. Above the inner wall surface of the movable cylinder 115, the base end side of the upper arm 117 is connected to the inside and outside of the movable cylinder 115 and the main body cylinder 111 through the opening of the movable cylinder 115 and the main body cylinder 111. It is connected so as to be rotatable about a horizontal axis so as to enable the swing movement of the front end side between them. The distal end side of the upper arm 117 is connected to the middle of the outer wall surface of the storage case 116 so as to be rotatable about the same horizontal axis as the base end side.

  In the middle in the vertical direction of the inner wall surface of the movable cylinder 115, the base end side of the lower arm 118 is connected to the inside of the movable cylinder 115 and the main body cylinder 111 through the opening of the movable cylinder 115 and the main body cylinder 111. It is connected so as to be rotatable about a horizontal axis so as to enable a swing movement on the tip side with the outside. The distal end side of the lower arm 118 is connected to the lower side of the outer wall surface of the storage case 116 so as to be rotatable about the same horizontal axis as the base end side.

  Below the inside of the main body cylinder 111, the base end side of the link arm 119 is between the inside and outside of the movable cylinder 115 and the main body cylinder 111 through the opening of the movable cylinder 115 and the main body cylinder 111. It is connected and supported so as to be pivotable about a horizontal axis so that the tip side can be swung. The distal end side of the link arm 119 is connected between the proximal end and the distal end of the lower arm 118 so as to be rotatable about the same horizontal axis as the proximal end side.

  That is, when the ball screw shaft 112 is rotated to lower the movable cylinder 115 via the support plate 113 and the drive shaft 114, the storage case 116 is moved by the action of the arms 117 to 119. 115 and the main body drum 111 are moved so as to be located from the inside to the outside (see FIG. 2), and the ball screw shaft 112 is rotated to rotate the movable cylinder 115 via the support plate 113 and the drive shaft 114. Is raised, the storage case 116 swings and moves so as to be located from the outside to the inside of the movable cylinder 115 and the main body barrel 111 by the action of the arms 117 to 119 (see FIG. 1). -ing

  Inside the storage case 116, a guide rail 120 whose longitudinal direction is directed up and down is attached. The guide rail 120 is provided with a gripper device 121 that detachably holds a fuel rod so as to be movable along the guide rail 120.

  In addition, one end (lower end) of an index shaft 123 whose axial direction is directed upward and downward is connected and fixed to the upper surface of the movable shaft 115, and the index shaft 123 is cut in the same radial direction as the drive shaft 114. It has an area and a linear expansion coefficient different from that of the drive shaft 114. The index shaft 123 is longer than the drive shaft 114 and penetrates the inside of the support plate 113 so as to be movable in the axial direction so that the other end (upper end) side is located above the support plate 113.

  As shown in FIG. 3, an output worm 123 a is formed on the upper end side of the index shaft 123 protruding above the support plate 113. A large-diameter worm wheel 124 is engaged with the output worm 123a. The large-diameter worm wheel 124 is engaged with a small-diameter worm wheel 125 having a smaller number of teeth than the worm wheel 124. The small-diameter worm wheel 125 meshes with an input worm 126 whose axial direction is directed upward and downward, and the input worm 126 is supported so that it can move (elevate and lower) in the axial direction as it rotates. ing. A moving plate 127 as a detection member is attached to the lower end of the input worm 126.

  That is, when the index shaft 123 expands and contracts in the axial direction due to thermal expansion, the large-diameter worm wheel 124 and the small-diameter worm wheel 125 rotate due to the vertical displacement of the output worm 123a accompanying the expansion and contraction of the index shaft 123. The moving plate 127 is moved (displaced) in the vertical direction via the input worm 126. At this time, the displacement amount of the output worm 123a is transmitted from the large-diameter worm 124 to the input worm 126 through the small-diameter worm 125, so that the input worm 126 is displaced more than the output worm 123a. To come.

  On the support plate 113 below the moving plate 127, a contact-type displacement sensor 128 that is a moving amount measuring means for measuring the moving amount (displacement amount) of the moving plate 127 is disposed. As shown in FIG. 4, the displacement sensor 128 is electrically connected to an input unit of an arithmetic control device 129 that is arithmetic control means. An output unit of the arithmetic control device 129 is electrically connected to a drive motor 122 that rotates the ball screw shaft 112, and the arithmetic control device 129 is configured to perform the driving based on information from the displacement sensor 128. The rotational speed of the motor 122 can be corrected and controlled (details will be described later).

  The main body drum 111 is disposed so as to be movable along the circumferential direction of the core above the core in the reactor, and is rotatable in the circumferential direction so that the direction of the front side can be switched. ing.

  In this embodiment, the ball screw shaft 112, the drive motor 122, and the like constitute lifting / lowering means, and the upper arm 117, the lower arm 118, etc. constitute swing support means, and the link arm 119 and the like constitute a rocking movement means, and the guide rail 120 and the gripper device 121 and the like constitute a fuel rod holding means, and the output worm 123a, the large-diameter worm wheel 124, the small-diameter worm wheel 125, The input worm 126, the moving plate 127, the displacement sensor 128, and the like constitute displacement amount measuring means.

  Next, the operation of the pantograph type fuel rod exchanging device 100 according to the present embodiment as described above will be described.

  First, after moving the main body cylinder 111 along the circumferential direction of the core so that the main body cylinder 111 is positioned at a position closest to a target spent fuel rod in the core, the arms 117 to 119 are moved. The gripper device 121 is positioned above the intended used fuel rod by swinging the storage case 116 from the inside of the movable cylinder 115 and the main body barrel 111 to the outside. Then, the drive motor 122 is operated to lower the movable cylinder 115 through the drive shaft 114 for a predetermined length.

  Then, when the gripper device 121 is lowered along the guide rail 120 and the upper part of the target spent fuel rod is gripped by the gripper device 121, the gripper device 121 is raised along the guide rail 120. As a result, after the fuel rod is stored in the storage case 116, the arms 117 to 119 are swung to move the storage case 116 from the outside to the inside of the movable cylinder 115 and the main body barrel 111. As a result, the drive motor 122 is operated so as to store the storage case 116 inside the movable cylinder 115, and the movable cylinder 115 is raised to a predetermined upper position via the drive shaft 114. .

  Subsequently, when the main body drum 111 is moved along the circumferential direction of the core so as to be positioned in the vicinity of the storage chamber, the drive motor 122 is operated to move the movable cylinder 115 to a predetermined position via the drive shaft 114. The arm 117 to 119 is swung by being lowered, and the spent fuel rod stored in the storage case 116 is positioned above the storage chamber, and then the gripper device 121 is moved down to The fuel rod is stored in the storage chamber.

  Next, when a new fuel rod in the storage chamber is gripped by the gripper device 121, the gripper device 121 is raised and the fuel rod is stored in the storage case 116, the storage case 116 is moved to the movable cylinder 115. The drive motor 122 is operated so as to be stored inside, and the movable cylinder 115 is raised to a predetermined upper position via the drive shaft 114, and then the main body cylinder 111 is moved along the circumferential direction of the core. Then, by moving the drive motor 122 again and lowering the movable cylinder 115 through the drive shaft 114 by a predetermined length, above the position where the previously extracted fuel rod is located, After the new fuel rod stored in the storage case 116 is positioned, the gripper device 121 is lowered to put the new fuel rod into the core. By such an operation, the fuel rod can be exchanged between the core and the storage chamber.

  In such a fuel rod replacement, the fuel rod replacement apparatus 100 is located in the sodium melt 1 (about 200 ° C.) near the lower portion where the fuel rod is handled because of the positional relationship in the furnace. Since the upper side is located in the atmosphere of the cover gas 2 in the furnace (about 150 ° C.), the movable cylinder 115 is raised so that the storage case 116 is positioned inside the movable cylinder 115. While the drive shaft 114 and the index shaft 123 are both located on the cover gas 2 side over the entire length, the movable cylinder 115 is lowered so that the storage case 116 is positioned outside the movable cylinder 115. Sometimes, both the drive shaft 114 and the index shaft 123 are positioned on the sodium melt 1 side.

  Here, since the index shaft 123 has the same cross-sectional area in the radial direction as the drive shaft 114 and a linear expansion coefficient different from that of the drive shaft 114, the movable cylinder 115 is lowered. When the lower side of the drive shaft 114 and the index shaft 123 is positioned on the sodium melt 1 side, the upper end side of the index shaft 123 is displaced relative to the support plate 113 due to the difference in linear expansion coefficient, that is, the support The worm 123a with respect to the plate 113 is displaced in the vertical direction.

  With the displacement of the worm 123a, the large-diameter worm wheel 124 and the small-diameter worm wheel 125 rotate, and the movable plate 127 moves (displaces) in the vertical direction via the worm 126, so that the movable plate The displacement sensor 128 measures the movement amount (displacement amount) of 127.

  The arithmetic and control unit 129 calculates the thermal expansion amount of the drive shaft 114 based on the information from the displacement sensor 128 and inputs the thermal expansion amount of the drive shaft 114 and the drive shaft 114 that are input in advance. It is calculated from the relationship between the correction value of the vertical movement amount, in other words, the correction value of the vertical movement amount of the movable cylinder 115 due to the rotation of the ball screw shaft 112, that is, the correction value of the rotational speed of the drive motor 122. A correction value for the rotational speed of the drive motor 122 corresponding to the thermal elongation amount is obtained, and the drive motor 122 is operated so that the drive motor 122 is operated at a rotational speed that takes the correction value into account.

  As a result, the movable cylinder 115 is corrected for an error in the amount of up-and-down movement of the movable cylinder 115 due to the thermal expansion of the drive shaft 114, so that the arms 117 to 119 are swung to move the storage case 116. When the swing movement is performed from the inside of the cylinder 115 and the main body drum 111 to the outside, the gripper device 121 can be accurately positioned at a target position.

  Further, when the movable cylinder 115 is raised and the drive shaft 114 and the index shaft 123 are located on the cover gas 2 side over the entire length, the index shaft 123 with respect to the support plate 113 due to the difference in the linear expansion coefficient. The upper end side of the worm 123a is displaced, that is, the worm 123a with respect to the support plate 113 is displaced in the vertical direction. With the displacement of the worm 123a, the large-diameter worm wheel 124 and the small-diameter worm wheel 125 rotate, and the worm 126, the moving plate 127 moves (displaces) in the vertical direction, and the displacement sensor 128 measures the amount of movement (displacement) of the moving plate 127. Similarly, since the drive motor 122 is operated by performing arithmetic processing, the arms 117 to 119 are swung to store the storage. Over a scan 116 when moving swinging from the exterior to the interior of the movable cylinder 115 and the main body cylinder 111, the storage case 116 can be stored securely in a defined position of the movable cylinder 115.

  Therefore, according to the fuel rod exchanging device 100 according to the present embodiment, it is possible to prevent a decrease in positioning accuracy due to thermal expansion of the drive shaft 114.

  Further, by transmitting the displacement amount of the output worm 123a from the large diameter worm 124 to the input worm 126 through the small diameter worm 125, the input worm 126 is displaced more than the output worm 123a. Thus, even if the thermal expansion difference between the drive shaft 114 and the index shaft 123 is small, the amount of movement of the moving plate 127 can be increased, and the displacement sensor 128 can reliably measure. .

  The index shaft 123 can be applied as long as it has a linear expansion coefficient different from that of the drive shaft 114, but the linear expansion coefficient αd of the drive shaft 114 and the linear expansion coefficient αi of the index shaft 123 are applicable. It is preferable that the difference Δα (= | αd−αi |) is 5.0 (1 / ° C.) or more because the displacement amount can be further easily measured.

  Specifically, for example, when SUS304 (linear expansion coefficient αd: 17.3 (1 / ° C.)) is applied to the material of the drive shaft 114, an aluminum alloy (linear expansion) is used as the material of the index shaft 123. Coefficient αi: 25.0 (1 / ° C.), iron (linear expansion coefficient αi: 11.7 (1 / ° C.)), or the like is preferably used.

[Other Embodiments]
In the above-described embodiment, the upper end side of the index shaft 123 that is longer than the drive shaft 114 is protruded above the support plate 113, so that the displacement sensor 128 or the like provided on the upper surface of the support plate 113 is used. The displacement amount on the upper end side of the index shaft 123 with respect to the support plate 113 is measured. However, as another embodiment, for example, with respect to the support plate 113 on the upper end side of the index shaft shorter than the drive shaft 114. It is also possible to measure the amount of displacement with a displacement sensor 128 or the like provided on the lower surface of the support plate 113.

  In the above-described embodiment, the case where the contact-type displacement sensor 128 is applied as the movement amount measuring unit has been described. However, for example, a laser-type non-contact-type displacement sensor or the like is applied as another embodiment. It is also possible.

  The fuel rod exchanging device according to the present invention can prevent a decrease in positioning accuracy due to thermal elongation of the drive shaft, and can be used extremely beneficially in a nuclear power plant or the like.

DESCRIPTION OF SYMBOLS 1 Sodium melt 2 Cover gas 100 Fuel rod changer 111 Main body trunk | ball 112 Ball screw shaft 113 Support plate 114 Drive shaft 115 Movable cylinder 116 Storage case 117 Upper arm 118 Lower arm 119 Link arm 120 Guide rail 121 Gripper device 122 Drive motor 123 Index shaft 123a Output worm 124 Large diameter worm wheel 125 Small diameter worm wheel 126 Input worm 127 Moving plate 128 Displacement sensor 129 Arithmetic control device

Claims (2)

An internal hollow main body barrel having an opening in the front face disposed so that the longitudinal direction is directed up and down;
An internal hollow movable cylinder disposed inside the main body trunk and having an opening in the front so that the longitudinal direction is directed up and down;
A drive shaft having a lower end coupled to the movable cylinder;
A support member coupled to an upper end of the drive shaft;
Elevating and moving means for supporting the supporting member and moving the movable cylinder up and down inside the main body body;
An internal hollow storage case that is disposed inside the movable cylinder so as to face the longitudinal direction up and down and has an opening on the lower surface;
A fuel rod holding means disposed in the storage case so as to be movable up and down and detachably holding the fuel rod;
Oscillating support means for supporting the storage case so as to oscillate and move between the movable cylinder and the inside of the body cylinder via the opening of the movable cylinder and the body cylinder;
As the movable cylinder is lowered, the storage case is positioned outside the movable cylinder and the main body cylinder, and as the movable cylinder is raised, the storage case is positioned inside the movable cylinder and the main body cylinder. Swing movement means for swinging the storage case,
An indicator shaft having a linear expansion coefficient different from that of the drive shaft, the lower end being coupled to the movable cylinder;
A displacement amount measuring means for measuring a displacement amount of the upper end side of the index shaft with respect to the support member;
Calculation control means for calculating the amount of thermal extension of the drive shaft based on the information from the displacement amount measuring means, and correcting the amount of vertical movement of the movable cylinder by the vertical movement means in accordance with the amount of thermal elongation. And a fuel rod changer comprising: The fuel rod changer according to claim 1, wherein
The displacement measuring means is
An output worm provided on the upper end side of the indicator shaft;
A large-diameter worm wheel meshing with the output worm,
A small-diameter worm wheel that meshes with the large-diameter worm wheel and has fewer teeth than the large-diameter worm wheel;
An input worm supported so as to be movable in the axial direction and meshing with the small-diameter worm wheel;
A detection member provided in the input worm;
A fuel rod exchanging device, comprising: a movement amount measuring means provided on the support member for measuring the movement amount of the detection member.

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