JP6482297B2 - Tool and processing method - Google Patents

Description

  The present invention relates to a tool and a machining method.

  A pressurized water reactor (PWR) is provided with a control rod for adjusting the output of the nuclear reactor and a control rod drive mechanism (CRDM) for driving the control rod. The control rod drive is located at the top of the reactor vessel. The control rod drive device performs an operation of inserting the control rod into the core and an operation of removing the control rod from the core. The control rod includes a control material that absorbs neutrons. The control rod absorbs neutrons generated in the core and adjusts the power of the reactor by adjusting the number of neutrons.

  As a control rod driving device, a magnetic jack type control rod driving device is known. The magnetic jack type control rod drive device includes a latch mechanism that can intermittently hold the control rod drive shaft and a latch housing that houses the latch mechanism. The latch mechanism drives the control rod drive shaft in the axial direction using electromagnetic force.

  An example of a magnetic jack type control rod drive device having a latch housing arranged around a latch mechanism and a rod housing arranged around a control rod drive shaft is disclosed in Patent Document 1. Both the latch housing and the rod housing are cylindrical members. The inner diameter of the latch housing is larger than the inner diameter of the rod housing.

JP-A-10-319164

  In Patent Document 1, the latch housing and the rod housing are integrated by welding. A portion corresponding to the latch housing and a portion corresponding to the rod housing may be manufactured with a single cylindrical member. In this case, a single cylindrical member is formed with a large diameter portion and a small diameter portion having an inner diameter smaller than that of the large diameter portion. When the inner diameter of the cylindrical member is machined, boring (spinning) using a lathe may be performed. In boring, a tool called a boring bar is used. The inner surface of the cylindrical member is processed by the boring bar.

  The boring bar has a shaft member and a tip terminal connected to the tip of the shaft member. The tip terminal includes a cutting tool. If the rigidity of the shaft member is insufficient, the tip terminal may vibrate during processing. If the inner surface of the cylindrical member is processed in a state where the tip terminal vibrates, the quality of the manufactured cylindrical member may deteriorate.

  An object of an aspect of the present invention is to provide a tool and a processing method in which a lack of rigidity is suppressed and a decrease in processing accuracy is suppressed.

  According to the first aspect of the present invention, the shaft member is a tool for processing the inner surface of the cylindrical member, and includes a tip terminal including a cutting tool and a shaft member to which the tip terminal is connected. Includes a main body portion having a distal end portion to which the tip terminal is connected, and a fixed portion that is disposed at a proximal end portion of the main body portion and is fixed to a lathe fixing device, and the central axis of the shaft member The base end portion has a first outer shape of a curved first contour, and the distal end portion has a second outer shape of a curved second contour, in a plane orthogonal to the first in-plane The first dimension indicating the first outer shape in a direction parallel to the axis is larger than the second dimension indicating the first outer shape in a direction parallel to the second axis in the plane perpendicular to the first axis, The second dimension is a third dimension indicating the second outer shape in a direction parallel to the first axis and a direction parallel to the second axis. The outer surface of the intermediate portion of the main body portion between the distal end portion and the proximal end portion is larger than or equal to the fourth dimension indicating the second outer shape, and the first contour and the A tool is provided that includes a curved surface connecting the second contour.

  According to the first aspect of the present invention, the first dimension is greater than the second dimension, the second dimension is greater than or equal to the third dimension and the fourth dimension, and the distal end and the proximal end The outer surface of the intermediate part between the parts includes a curved surface connecting the first contour and the second contour. Thereby, the dimension of the main body part in the direction parallel to the first axis of the base end part and the intermediate part is larger than the dimension of the base part of the main body part in the direction parallel to the second axis. Therefore, the rigidity of the main body in the direction parallel to the first axis is increased. Therefore, even if a force in a direction parallel to the first axis acts on the main body, the vibration of the tip terminal including the cutting tool is suppressed. Therefore, a decrease in processing accuracy is suppressed, and a decrease in the quality of the manufactured cylindrical member is suppressed.

  1st aspect of this invention WHEREIN: The said cutting tool may be arrange | positioned so that it may protrude in the direction parallel to the said 2nd axis | shaft from the outer surface of the said main-body part.

  Thereby, a force in a direction parallel to the first axis is applied to the cutting tool. Even if a force in a direction parallel to the first axis is applied to the cutting tool and a force in a direction parallel to the first axis is applied to the main body, vibration of the tip terminal including the cutting tool is suppressed. Therefore, a reduction in processing accuracy is suppressed. Moreover, the operation | movement which inserts a tool in a cylindrical member is performed smoothly.

  1st aspect of this invention WHEREIN: The said cylindrical member is rotated in the state which the inner surface of the said cylindrical member and the said bite contacted, and the inner surface of the boundary part of the large diameter part of the said cylindrical member, and a small diameter part In this processing, it may be moved in a direction parallel to the second axis.

  As a result, the boundary portion can be processed with high accuracy in a state in which the occurrence of vibration of the tip terminal is suppressed. Further, in the processing, interference between the cylindrical member and the main body is suppressed.

  In the first aspect of the present invention, the first outer shape may be elliptical.

  Thereby, a main-body part with high rigidity can be manufactured smoothly.

  In the first aspect of the present invention, an outer shape of at least a part of the intermediate portion may be elliptical in the plane.

  Thereby, a main-body part with high rigidity can be manufactured smoothly.

  In the first aspect of the present invention, the second dimension and the fourth dimension may be equal, and the first dimension may be larger than the third dimension.

  As a result, it is possible to obtain a main body having high rigidity while suppressing an increase in diameter of the main body in the direction parallel to the second axis.

  In the first aspect of the present invention, the third dimension and the fourth dimension may be equal.

  Thereby, the enlargement of the tip is suppressed.

  In the first aspect of the present invention, the second outer shape may be a perfect circle.

  Thereby, a main part with high rigidity can be manufactured smoothly, suppressing enlargement of a tip part.

  According to the second aspect of the present invention, there is provided a processing method for processing an inner surface of a cylindrical member, wherein the cylindrical member includes a large-diameter portion having a first length and a large-diameter portion via a boundary portion. A small-diameter portion having a second length shorter than the first length, and the tool of the first aspect is inserted into the internal space of the tubular member from the opening disposed at the end of the small-diameter portion. Inserting the cutting tool into contact with the inner surface of the cylindrical member and the cutting tool disposed so as to protrude from the outer surface of the main body in a direction parallel to the second axis, and rotating the cylindrical member. And moving the tool in a direction parallel to the second axis.

  According to the second aspect of the present invention, the inner surface of the cylindrical member is processed while suppressing a decrease in processing accuracy, using a tool in which lack of rigidity in a direction parallel to the first axis is suppressed. Can do.

  In the second aspect of the present invention, the cylindrical member includes a latch housing that is provided in the nuclear reactor and houses a latch mechanism that intermittently holds a control rod drive shaft that moves in the vertical direction. At least one of the portions of the large-diameter portion adjacent to the boundary portion includes a fitting portion that holds the latch mechanism, and using the tool, the inner surface of the boundary portion and the inner surface of the portion of the large-diameter portion are used. May be processed.

  Thereby, the fitting part of the latch housing in which high processing accuracy is required can be processed with high processing accuracy.

  According to the aspects of the present invention, there are provided a tool and a machining method in which a lack of rigidity is suppressed and a decrease in machining accuracy is suppressed.

FIG. 1 is a schematic diagram illustrating an example of a nuclear reactor including a control rod driving device according to the present embodiment. FIG. 2 is a cross-sectional view showing a part of the control rod driving apparatus according to the present embodiment. FIG. 3 is a sectional view showing an example of the latch housing according to the present embodiment. FIG. 4 is a perspective view showing an example of a tool according to the present embodiment. FIG. 5 is a side view showing an example of the shaft member of the tool according to the present embodiment. FIG. 6 is a side view showing an example of the shaft member of the tool according to the present embodiment. FIG. 7 is a cross-sectional view showing an example of the base end portion according to the present embodiment, and corresponds to a cross-sectional view taken along line AA in FIG. FIG. 8 is a cross-sectional view showing an example of the tip portion according to the present embodiment, and corresponds to a cross-sectional view taken along the line BB in FIG. FIG. 9 is a cross-sectional view showing an example of the intermediate portion according to the present embodiment, and corresponds to a cross-sectional view taken along the line CC in FIG. FIG. 10 is a cross-sectional view showing an example of the tip portion according to the present embodiment. FIG. 11 is a cross-sectional view showing an example of a tip portion according to the present embodiment. FIG. 12 is a cross-sectional view showing an example of the base end portion according to the present embodiment. FIG. 13 is a diagram schematically illustrating an example of a method for processing a cylindrical member using the tool according to the present embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The components of each embodiment described below can be combined as appropriate. Some components may not be used.

  FIG. 1 is a schematic diagram illustrating an example of a nuclear reactor 100 including a control rod driving device 125 according to the present embodiment. A nuclear reactor 100 shown in FIG. 1 is a pressurized water reactor (PWR). In the reactor 100 according to the present embodiment, a reactor vessel 101 provided as a pressure vessel is mounted on the reactor vessel body 102 and the upper portion of the reactor vessel body 102 and can be opened and closed with respect to the reactor vessel body 102. And a reactor vessel lid 103. The reactor vessel main body 102 is formed with an inlet nozzle 104 and an outlet nozzle 105 for supplying and discharging light water as primary cooling water that is cooling water used in the primary cooling system.

  Below the inlet nozzle 104 and the outlet nozzle 105, a core tank 110 formed in a substantially cylindrical shape is provided. The upper part of the core tank 110 is connected to the upper core plate 111. The lower part of the core tank 110 is connected to the lower core plate 112.

  An upper core support plate 113 is fixed above the core tank 110. The upper core support plate 113 is provided by suspending a plurality of core support rods 114, and the upper core plate 111 is suspended and supported via the core support rods 114. The lower core plate 112 is positioned and held by a plurality of radial keys 115 with respect to the inner surface of the reactor vessel main body 102.

  The core 120 includes a core tank 110, an upper core plate 111, and a lower core plate 112. A large number of fuel assemblies 121 are arranged in the core 120. The fuel assembly 121 is configured such that a control rod 122 can be inserted. A plurality of upper ends of the control rod 122 are combined into a control rod cluster 123. The upper core plate 111 is supported by a number of control rod cluster guide tubes 124 that penetrate the upper core support plate 113. The control rod cluster guide tube 124 guides the control rod cluster 123. A control rod drive shaft 140 extending from the control rod drive device 125 is connected to the control rod cluster 123 through the control rod cluster guide tube 124 and extends to the fuel assembly 121.

  A portion communicating with the outlet nozzle 105 is formed as an upper plenum 131. A hemispherical space formed by the lower core plate 112 and the inner surface of the spherically closed portion at the bottom of the reactor vessel body 102 is formed as a lower plenum 132. A portion communicating with the inlet nozzle 104 and the lower plenum 132 is formed as a downcomer portion 133.

  When fission reaction is performed on the fissile material, the amount of control rod 122 inserted into the fuel assembly 121 is adjusted by a control rod driving device 125 provided in the reactor vessel lid 103. Thereby, the fission reaction in the core 120 is controlled.

  FIG. 2 is a cross-sectional view showing a part of the control rod driving device 125 according to the present embodiment. The control rod driving device 125 is provided in the nuclear reactor 100. The control rod drive device 125 moves the control rod drive shaft 140. The control rod drive device 125 moves the control rod drive shaft 140 in a direction (vertical direction) parallel to the central axis of the control rod drive shaft 140. As the control rod drive shaft 140 moves in the vertical direction, the control rod 122 connected to the control rod drive shaft 140 via the control rod cluster 123 moves in the vertical direction.

  The control rod drive device 125 includes a drive shaft guide tube 161 that guides the control rod drive shaft 140, a latch mechanism 146 that can move while holding the control rod drive shaft 140 intermittently, and the control rod drive shaft 140 in the vertical direction. And a drive mechanism 152 that moves to the right. A plurality of circumferential grooves 140 a are provided on the surface of the control rod drive shaft 140.

  The latch mechanism 146 is connected to the fixed grip latch support tube 141, the fixed grip latch 142 that can be disposed in any one of the plurality of peripheral grooves 140 a of the control rod drive shaft 140, and the fixed grip latch 142. A fixed grip latch link 143, a fixed grip plunger 144, and a fixed grip coil 145 that drives the fixed grip latch 142 via the fixed grip latch link 143 and the fixed grip plunger 144. The latch mechanism 146 holds the control rod drive shaft 140 by arranging the fixed grip latch 142 in the circumferential groove 140a.

  The drive mechanism 152 includes a movable grip latch 147 that can be disposed in any one of the plurality of peripheral grooves 140a of the control rod drive shaft 140, a movable grip latch link 148 that is coupled to the movable grip latch 147, A movable gripper plunger 149, a movable gripper latch link 148, a movable gripper coil 149 for driving the movable gripper latch 147 via the movable gripper plunger 149, and a liftable coil for moving the movable gripper latch link 148 and the movable gripper plunger 149 vertically. 151. The drive mechanism 152 holds the control rod drive shaft 140 by disposing the movable grip latch 147 in the circumferential groove 140a. With the control rod drive shaft 140 held by the movable grip latch 147, the movable grip latch link 148 and the movable grip plunger 149 are moved in the vertical direction by the operation of the raising coil 151, so that the control rod drive shaft 140 is moved up and down. Move in the direction.

  The latch mechanism 146 intermittently holds the control rod drive shaft 140 that moves in the vertical direction. By holding the control rod drive shaft 140 in the latch mechanism 146, the position of the control rod drive shaft 140 in the vertical direction is determined.

  Further, the control rod driving device 125 has a fixed gripping magnetic pole 153 excited by the fixed gripping coil 145, a movable gripping magnetic pole 154 excited by the movable gripping coil 150, and a lifting magnetic pole 155 excited by the lifting coil 151. . Further, the control rod driving device 125 includes a return spring 156A, a return spring 156B, and a return spring 156C.

  When the fixed gripping magnetic pole 153 is demagnetized by the fixed gripping coil 145, the fixed gripping latch 142 moves to the outside of the circumferential groove 140a of the control rod drive shaft 140. When the movable gripping magnetic pole 154 is excited by the movable gripping coil 150, the movable gripping latch 147 is disposed inside the circumferential groove 140a of the control rod drive shaft 140. When the raising magnetic pole 155 is excited by the raising coil 151 in a state where the movable clamping latch 147 is disposed inside the circumferential groove 140 a, the movable clamping magnetic pole 154 and the movable clamping latch 147 return together with the movable clamping coil 150. It moves to the raised magnetic pole 155 side against the biasing force of the spring 156A. As a result, the control rod drive shaft 140 is raised by one pitch of the circumferential groove 140a.

  When the fixed gripping magnetic pole 153 is excited by the fixed gripping coil 145, the fixed gripping latch 142 is disposed inside the circumferential groove 140a of the control rod drive shaft 140. When the movable gripping magnetic pole 154 is demagnetized by the movable gripping coil 150 and the lifting magnetic pole 155 is demagnetized by the lifting coil 151, the movable gripping latch 147 moves to the outside of the circumferential groove 140 a of the control rod drive shaft 140. Thus, the movable gripping magnetic pole 154 and the movable gripping latch 147 are lowered together with the movable gripping coil 150 by the biasing force of the return spring 156A.

  After the movable gripping magnetic pole 154 is excited by the movable gripping coil 150 and the movable gripping latch 147 is disposed inside the circumferential groove 140a of the control rod drive shaft 140, the stationary gripping magnetic pole 153 is demagnetized by the stationary gripping coil 145, and the stationary gripping. The latch 142 is disposed outside the circumferential groove 140 a of the control rod drive shaft 140. When the movable gripping magnetic pole 154 is excited by the movable gripping coil 150 in a state where the stationary gripping latch 142 is disposed outside the circumferential groove 140 a of the control rod driving shaft 140, the movable gripping latch 147 is moved around the control rod driving shaft 140. It arrange | positions inside the groove | channel 140a. When the raising magnetic pole 155 is excited by the raising coil 151 in a state where the movable clamping latch 147 is disposed inside the circumferential groove 140 a, the movable clamping magnetic pole 154 and the movable clamping latch 147 return together with the movable clamping coil 150. It moves to the raised magnetic pole 155 side against the biasing force of the spring 156A. As a result, the control rod drive shaft 140 is raised by one pitch of the circumferential groove 140a.

  The control rod drive 125 includes a control rod drive housing 160. The control rod drive device housing 160 includes a drive shaft guide tube 161 that houses the control rod drive shaft 140, and a latch housing 162 that is disposed so as to surround a part of the outer periphery of the drive shaft guide tube 161 and accommodates the latch mechanism 146. The coil housing 165 that houses the drive mechanism 152 and the cap 163 (see FIG. 1) that closes the upper end of the drive shaft guide tube 161 are provided.

  The lower end of the latch housing 162 is connected to a cylindrical nozzle 164 that is welded through the reactor vessel lid 103. The drive shaft guide tube 161 is inserted from the upper end of the latch housing 162 and connected to the latch housing 162. Then, assuming that the control rod drive shaft 140 has failed, in order to take out the control rod drive shaft 140, the nozzle 164 and the latch housing 162, the latch housing 162 and the drive shaft guide tube 161, the drive shaft guide tube 161 and the cap 163 are taken out. Are detachably connected to each other by screw connection.

  The latch housing 162 includes a large diameter portion 162A, a small diameter portion 162B having an inner diameter smaller than that of the large diameter portion 162A, and a boundary portion 162C between the large diameter portion 162A and the small diameter portion 162B. The boundary portion 162C and a part of the large diameter portion 162A adjacent to the boundary portion 162C function as the fitting portion 40 that holds the latch mechanism 146. The latch mechanism 146 is fixed to the latch housing 162 by fitting at least a part of the latch mechanism 146 into the fitting portion 40 of the latch housing 162.

  FIG. 3 is a cross-sectional view showing an example of the latch housing 162 according to the present embodiment. The latch housing 162 is a cylindrical member. As shown in FIG. 3, the latch housing 162 is disposed around the central axis AXh. The latch housing 162 includes a large diameter portion 162A, a small diameter portion 162B having an inner diameter smaller than that of the large diameter portion 162A, and a boundary portion 162C between the large diameter portion 162A and the small diameter portion 162B. The small diameter portion 162B is connected to the large diameter portion 162A via the boundary portion 162C.

  As described above, the boundary portion 162 </ b> C and a part of the large diameter portion 162 </ b> A adjacent to the boundary portion 162 </ b> C function as the fitting portion 40 that holds the latch mechanism 146. The fitting part 40 may include a part of the small diameter part 162B adjacent to the boundary part 162C. At least one of the boundary part 162C, a part of the large diameter part 162A, and a part of the small diameter part 162B may function as the fitting part 40.

  With respect to the direction parallel to the central axis AXh, the large diameter portion 162A of the latch housing 162 has a first length L1. The small diameter portion 162B has a second length L2. The boundary portion 162C has a third length L3. The second length L2 is shorter than the first length L1. The third length L3 is shorter than the first length L1 and the second length L2.

  The latch housing 162 includes a first opening 171 disposed at the end of the large diameter portion 162A and a second opening 172 disposed at the end of the small diameter portion 162B.

  In the plane orthogonal to the central axis AXh, the large diameter portion 162A is circular. In the plane orthogonal to the central axis AXh, the small diameter portion 162B is circular. In the plane orthogonal to the central axis AXh, the boundary portion 162C is circular. In the plane orthogonal to the central axis AXh, the first opening 171 is circular. In the plane orthogonal to the central axis AXh, the second opening 172 is circular. The inner diameter of the large diameter portion 162A is larger than the inner diameter of the small diameter portion 162B. The first opening 171 is larger than the second opening 172.

  In a plane parallel to the central axis AXh, the inner surface of the boundary portion 162C is inclined so as to approach the central axis AX from the large diameter portion 162A toward the small diameter portion 162B. The inner diameter of the boundary portion 162C gradually decreases from the large diameter portion 162A toward the small diameter portion 162B.

  FIG. 4 is a perspective view showing an example of the tool 1 according to the present embodiment. FIG. 5 is a side view showing a part of the tool 1 according to the present embodiment. FIG. 6 is a side view showing a part of the tool 1 according to the present embodiment.

  In the following description, an XYZ orthogonal coordinate system is set as appropriate, and the positional relationship of each part will be described with reference to this XYZ orthogonal coordinate system. One direction in the predetermined plane is defined as the X-axis direction, the direction orthogonal to the X-axis in the predetermined plane is defined as the Y-axis direction, and the direction orthogonal to the predetermined plane is defined as the Z-axis direction. Further, rotation around the X axis (inclination direction) is the θX direction, rotation around the Y axis (inclination direction) is the θY direction, and rotation around the Z axis (inclination direction) is the θZ direction. The XY plane includes the X axis and the Y axis and is orthogonal to the Z axis. The XZ plane includes the X axis and the Z axis and is orthogonal to the Y axis. The YZ plane includes the Y axis and the Z axis and is orthogonal to the X axis. FIG. 5 is a view of a part of the tool 1 as viewed from the + Z side. FIG. 6 is a view of a part of the tool 1 as viewed from the −X side.

  As shown in FIGS. 4, 5, and 6, the tool 1 includes a tip terminal 3 including a cutting tool 2 and a shaft member 4 to which the tip terminal 3 is connected. The tool 1 includes a boring bar used for inner diameter machining of a cylindrical member. The tool 1 is a tool for processing the inner surface of a cylindrical member. The tool 1 is used when boring (boring) a cylindrical member using a lathe. The inner surface of the cylindrical member is processed by the tool 1. In the present embodiment, the inner surface of the latch housing 162 is processed using the tool 1.

  The tip terminal 3 is detachably connected to the shaft member 4. The tip terminal 3 is fixed to the shaft member 4 by a fixing member 10 such as a bolt member. The tip terminal 3 is removed from the shaft member 4 by releasing the fixing by the fixing member 10. 5 and 6 are views showing the shaft member 4 with the tip terminal 3 removed.

  The shaft member 4 has a central axis AXb. 4, 5, and 6, the central axis AXb is parallel to the Y axis. The central axis AXb is orthogonal to the XZ plane.

  The shaft member 4 includes a main body portion 5 having a distal end portion 7 to which a tip terminal 3 is connected, and a fixed portion 6 that is disposed at a base end portion 8 of the main body portion 5 and is fixed to a lathe fixing device. . The main body 5 and the fixed part 6 are integrated. The main body 5 and the fixed part 6 are a single member.

  The shaft member 4 includes a distal end portion 7, a proximal end portion 8, and an intermediate portion 9 between the distal end portion 7 and the proximal end portion 8. The tip portion 7 includes a tip surface to which the tip terminal 3 is attached. The base end portion 8 is fixed to the fixed portion 6.

  FIG. 7 is a cross-sectional view showing an example of the base end 8 according to the present embodiment, and corresponds to a cross-sectional view taken along the line AA in FIG. FIG. 8 is a cross-sectional view showing an example of the distal end portion 7 according to the present embodiment, and corresponds to a cross-sectional view taken along the line BB in FIG. FIG. 9 is a cross-sectional view showing an example of the intermediate portion 9 according to the present embodiment, and corresponds to a cross-sectional view taken along the line CC in FIG.

  As shown in FIGS. 4, 5, 6, 7, 8, and 9, in the XZ plane orthogonal to the central axis AXb of the shaft member 4, the base end portion 8 has a first contour first. It has an outer shape. The distal end portion 7 has a second outer shape having a second contour. As shown in FIG. 7, the first contour of the first outer shape of the base end portion 8 is a curve. As shown in FIG. 8, the second contour of the second outer shape of the tip 7 is a curve.

  As shown in FIG. 7, in the XZ plane, the dimension of the first outer shape of the base end portion 8 in the X-axis direction is the first dimension D1. In the XZ plane, the dimension of the first outer shape of the base end portion 8 in the Z-axis direction orthogonal to the X-axis direction is the second dimension D2. The first dimension D1 indicating the first outer shape in the X-axis direction is larger than the second dimension D2 indicating the first outer shape in the Z-axis direction.

  As shown in FIG. 8, in the XZ plane, the dimension of the second outer shape of the tip 7 in the X-axis direction is a third dimension D3. In the XZ plane, the dimension of the second outer shape of the distal end portion 7 in the Z-axis direction orthogonal to the X-axis direction is a fourth dimension D4. In the present embodiment, the third dimension D3 and the fourth dimension D4 are equal.

  In the present embodiment, the second dimension D2 is equal to the third dimension D3 and the fourth dimension D4. The second dimension D2 and the fourth dimension D4 are equal, and the first dimension D1 is larger than the third dimension D3.

  In this embodiment, the 1st external shape of the base end part 8 in XZ plane is an ellipse. The second outer shape of the tip 7 in the XZ plane is a true circle.

  That is, in the present embodiment, the proximal end portion 8 is thicker than the distal end portion 7. The dimension (second dimension D2) of the base end part 8 in the Z-axis direction is equal to the dimension (fourth dimension D4) of the tip part 7, and the dimension (first dimension D1) of the base end part 8 in the X-axis direction is It is larger than the dimension (third dimension D3) of the tip part 7.

  The second dimension D2 may be larger than the third dimension D3 and the fourth dimension D4.

  The outer surface of the intermediate portion 9 is disposed so as to connect the first contour of the first outer shape of the base end portion 8 and the second contour of the second outer shape of the distal end portion 7. At least a part of the outer surface of the intermediate portion 9 includes a curved surface.

  As shown in FIG. 9, in the XZ plane, the dimension of the third outer shape of the intermediate portion 9 in the X-axis direction is the fifth dimension D5. In the XZ plane, the dimension of the third outer shape of the intermediate portion 9 in the Z-axis direction orthogonal to the X-axis direction is a sixth dimension D6.

  In the present embodiment, the sixth dimension D6 is equal to the second dimension D2. The fifth dimension D5 is larger than the third dimension D3 and smaller than the first dimension D1.

  In the XZ plane, the outer shape of at least a part of the intermediate portion 9 is elliptical. In the example shown in FIG. 9, in the XZ plane, the intermediate portion 9 has a shape in which a part on the + X side of the ellipse and a part on the −X side are cut out.

  In at least a part of the intermediate part 9, the fifth dimension D <b> 5 of the intermediate part 9 may be equal to the first dimension D <b> 1 of the base end part 8. In at least a part of the intermediate part 9, the fifth dimension D5 of the intermediate part 9 may be smaller than the first dimension D1 of the base end part 8 and larger than the third dimension D3 of the distal end part 7. In at least a part of the intermediate portion 9, the fifth dimension D5 of the intermediate portion 9 may be equal to the third dimension D3 of the distal end portion 7.

  In at least a part of the intermediate portion 9, the sixth dimension D6 of the intermediate portion 9 may be equal to the second dimension D2 of the base end portion 8. In at least a part of the intermediate portion 9, the sixth dimension D6 of the intermediate portion 9 may be smaller than the second dimension D2 of the proximal end portion 8 and larger than the fourth dimension D4 of the distal end portion 7. In at least a part of the intermediate portion 9, the sixth dimension D6 of the intermediate portion 9 may be equal to the fourth dimension D4 of the tip portion 7.

  FIG. 10 is a diagram illustrating another example of the distal end portion 7. As shown in FIG. 10, the tip end portion 7 does not have to be a perfect circle in the XZ plane. As shown in FIG. 10, the tip 7 may have an oval shape in which the third dimension D3 is larger than the fourth dimension D4. Also in the example shown in FIG. 10, the second dimension D2 of the base end portion 8 is equal to the fourth dimension D4 or larger than the third dimension D3 and the fourth dimension D4.

  FIG. 11 is a diagram illustrating another example of the distal end portion 7. As shown in FIG. 11, in the XZ plane, the second contour of the tip 7 may include a straight line. As shown in FIG. 11, the tip 7 may be a quadrilateral having rounded corners. Also in the example shown in FIG. 11, the second dimension D2 of the base end portion 8 is equal to the fourth dimension D4 or larger than the third dimension D3 and the fourth dimension D4.

  FIG. 12 is a diagram illustrating another example of the base end portion 8. As shown in FIG. 12, the base end portion 8 may not be elliptical in the XZ plane. Further, as shown in FIG. 12, the first contour of the base end portion 8 may include a straight line in the XZ plane. As shown in FIG. 12, the base end 8 may be a quadrilateral having rounded corners. Also in the example shown in FIG. 12, the first dimension D1 of the base end portion 8 is larger than the second dimension D2.

  Next, an example of a processing method for processing the inner surface of the latch housing 162 using the tool 1 according to the present embodiment will be described with reference to FIG. FIG. 13 is a diagram schematically illustrating an example of a processing method of the latch housing 162 using the tool 1 according to the present embodiment.

  In order to process the inner surface of the latch housing 162, the latch housing (tubular member) 162 is held by the rotating device 20 of the lathe. The tool 1 is held by a lathe fixing device 30. The fixed part 6 of the tool 1 is fixed to the fixing device 30.

  The lathe performs boring (boring) of the latch housing 162 using the tool 1. The inner surface of the latch housing 162 is processed by the tool 1.

  The rotating device 20 can rotate the latch housing 162 about the central axis AXh while holding the outer surface of the large-diameter portion 162A of the latch housing 162. In the present embodiment, the latch housing 162 is rotated in the θY direction about the central axis AXh by the rotating device 20. The position of the latch housing 162 in the X axis direction, the Y axis direction, and the Z axis direction is fixed. The rotating device 20 rotates the latch housing 162 in the θY direction while fixing the position of the latch housing 162 in the X axis direction, the Y axis direction, and the Z axis direction.

  The fixing device 30 moves in at least one of the X-axis direction, the Y-axis direction, and the Z-axis direction while holding the fixed portion 6 of the tool 1. The tool 1 does not rotate.

  In the present embodiment, the tool 1 is inserted into the internal space of the latch housing 162 from the second opening 172 disposed at the end of the small diameter portion 162 </ b> B of the latch housing 162. The inner surface of the latch housing 162 and the cutting tool 2 of the tool 1 are in contact with each other in a state where at least a part of the main body portion 5 of the shaft member 4 is disposed in the internal space of the second opening 172 and the small diameter portion 162B. In a state where the inner surface of the latch housing 162 and the cutting tool 2 of the tool 1 are in contact with each other, the latch housing 162 rotates about the central axis AXh. Thereby, the inner surface of the latch housing 162 is machined by the cutting tool 2 of the tool 1.

  Thus, in the present embodiment, the latch housing 162 is rotated in a state where at least a part of the main body portion 5 of the shaft member 4 is disposed in the internal space of the second opening 172 and the small diameter portion 162B, and the latch housing 162 is rotated. At least a part of the inner surface is processed with the cutting tool 2.

  As shown in FIGS. 4 and 13, in this embodiment, the cutting tool 2 is disposed so as to protrude from the outer surface of the main body 5 in the Z-axis direction. In the present embodiment, the cutting tool 2 is disposed so as to protrude from the main body 5 in the + Z direction.

  By rotating the latch housing 162 in a state where the cutting tool 2 arranged so as to protrude in the Z-axis direction from the outer surface of the main body 5 and the inner surface of the latch housing 162 are in contact with each other, at least the inner surface of the latch housing 162 is Part is processed. In the present embodiment, at least the inner surface of the boundary portion 162C and the inner surface of a portion of the large diameter portion 162A adjacent to the boundary portion 162C are processed using the tool 1. That is, in the present embodiment, at least the fitting portion 40 is processed using the tool 1.

  As described above, in the present embodiment, the tool 1 is moved in the Z-axis direction by the fixing device 30 in the XZ plane. On the other hand, the tool 1 is not moved in the X-axis direction. That is, in the present embodiment, the tool 1 is moved in the Z-axis direction in machining the inner surface of the boundary portion 162C between the large diameter portion 162A and the small diameter portion 162B of the latch housing 162. The tool 1 is not moved in the X-axis direction.

  The lathe moves the tool 1 in the Z-axis direction while rotating the latch housing 162 in a state where the cutting tool 2 and the inner surface of the latch housing 162 are in contact with each other. Thereby, the inner diameter of the latch housing 162 is adjusted. As the fixing device 30 moves in the Y-axis direction, the relative position of the latch housing 162 and the cutting tool 2 in the Y-axis direction changes. Thereby, the cutting tool 2 can process at least a part of the inner surface of the small diameter part 162B, the inner surface of the boundary part 162C, and at least a part of the inner surface of the large diameter part 162A.

  The fitting portion 40 is a portion that holds the latch mechanism 146. Therefore, high processing accuracy is required in processing the fitting portion 40.

  When processing the fitting portion 40, the tool 1 is inserted into the internal space of the latch housing 162 from the first opening 171 disposed at the end of the large diameter portion 162A, and the cutting tool 2 and the inner surface of the fitting portion 40 are connected. And a method of bringing the tool 2 into contact with the inner surface of the fitting portion 40 by inserting the tool 1 into the internal space of the latch housing 162 from the second opening 172 disposed at the end of the small diameter portion 162B. Conceivable.

  As described above, in the present embodiment, the first length L1 of the large diameter portion 162A is longer than the second length L2 of the small diameter portion 162B. Therefore, in the case of the method in which the tool 1 is inserted into the internal space of the latch housing 162 from the first opening 171 disposed at the end of the large diameter portion 162A and the bite 2 and the inner surface of the fitting portion 40 are brought into contact with each other, the shaft It is necessary to increase the length of the main body 5 of the member 4. When the length of the main body 5 is long, there is a high possibility that vibration of the tip terminal 3 including the cutting tool 2 (vibration such as self-excited vibration) occurs when the fitting part 40 using the cutting tool 2 is processed. In order to suppress the vibration of the tip 3, a measure for increasing the thickness of the main body 5 according to the length of the main body 5 can be considered. Generally, it is said that when the tool 1 is designed so that the value of “(length of the main body part 5) / (thickness of the main body part 5)” is 10 or less, vibration of the tip terminal 3 is suppressed. ing. However, the first length L1 of the large-diameter portion 162A and the inner diameter of the large-diameter portion 162A are predetermined values. Therefore, if the thickness of the main body 5 is increased in order to suppress the vibration of the tip terminal 3, the possibility that the tool 1 cannot be inserted from the first opening 171 increases.

  In the present embodiment, the tool 1 is inserted into the internal space of the latch housing 162 from the second opening 172 disposed at the end of the small diameter portion 162B, and the cutting tool 2 and the inner surface of the fitting portion 40 are brought into contact with each other. The second length L2 of the small diameter portion 162B is shorter than the first length L1 of the large diameter portion 162A. Therefore, even if the length of the main body portion 5 of the shaft member 4 is short, the cutting tool 2 can be brought into contact with the inner surface of the fitting portion 40. Since the length of the main body portion 5 of the shaft member 4 can be shortened, the main body portion 5 of the shaft member 4 does not need to be excessively thick in order to suppress the vibration of the tip terminal 3. Since the main body 5 of the shaft member 4 does not need to be thickened, the tool 1 is inserted into the internal space of the latch housing 162 from the second opening 172, and the tool 2 of the tool 1 contacts the inner surface of the fitting portion 40. Can be made.

  In this embodiment, the cutting tool 2 is disposed so as to protrude from the outer surface of the main body 5 in the Z-axis direction, and the tool 1 moves in the Z-axis direction while rotating the latch housing 162. When the inner surface of the rotating latch housing 162 and the cutting tool 2 come into contact with each other, a force in the X-axis direction exclusively acts on the main body 5. In the present embodiment, the first dimension D1 in the X-axis direction of the base end portion 8 is larger than the second dimension D2 in the Z-axis direction. The second dimension D2 is equal to or greater than the third dimension D3 in the X-axis direction and the fourth dimension D4 in the Z-axis direction of the distal end portion 7. That is, the dimension (thickness) of the intermediate part 9 and the base end part 8 in the X-axis direction is larger than the dimension (thickness) of the intermediate part 9 and the base end part 8 in the Z-axis direction. Thereby, the rigidity of the main-body part 5 of the X-axis direction is improved. Therefore, even when the inner surface of the latch housing 162 and the cutting tool 2 come into contact with each other during processing, and the force in the X-axis direction acts on the distal end portion 3 and the main body portion 5, the cutting tool 2 Occurrence of vibration of the tip portion 3 including is suppressed.

  Further, the size of the intermediate portion 9 and the base end portion 8 in both the X-axis direction and the Z-axis direction is not increased with respect to the size of the tip end portion 7, but exclusively the intermediate portion 9 and the base end portion in the X-axis direction. 8 is made larger than the size of the distal end portion 7, and the dimensions of the intermediate portion 9 and the base end portion 8 in the Z-axis direction are substantially equal to the dimensions of the distal end portion 7. The rigidity of the main body 5 can be increased only in the direction in which the rigidity is desired to be increased while suppressing the increase in diameter (enlarging). Since the diameter of the intermediate portion 9 and the base end portion 8 in the X axis direction is increased and the diameter of the intermediate portion 9 and the base end portion 8 in the Z axis direction is suppressed, the main body portion 5 in the X axis direction is suppressed. The relative movement between the tool 1 and the latch housing 162 in the XZ plane can be smoothly performed in a state where at least a part of the main body portion 5 is disposed in the second opening 172 and the small diameter portion 162B while increasing the rigidity. For example, during processing, interference (contact) between the latch housing 162 and the main body 5 is suppressed.

  As described above, according to the present embodiment, the first dimension D1 is larger than the second dimension D2, and the second dimension D2 is larger than the third dimension D3 and the fourth dimension D4, or the fourth dimension D2. Equal to dimension D4. The outer surface of the intermediate portion 9 between the distal end portion 7 and the base end portion 8 includes a curved surface connecting the first contour and the second contour. Thereby, the dimension of the base end part 8 and the intermediate part 9 of the main body part 5 in the X-axis direction can be made larger than the dimension of the base end part 8 and the intermediate part 9 of the main body part 5 in the Z-axis direction. Therefore, the rigidity of the main body 5 in the X-axis direction can be increased. Therefore, even if a force in the X-axis direction acts on the main body 5, vibration of the tip terminal 3 including the cutting tool 2 is suppressed. Accordingly, a decrease in machining accuracy is suppressed, and a decrease in quality of the manufactured latch housing 162 is suppressed.

  Further, according to the present embodiment, the cutting tool 2 is disposed so as to protrude in the Z-axis direction from the outer surface of the main body 5. Thereby, the inner surface of the latch housing 162 is processed smoothly. In processing, even if a force is applied to the cutting tool 2 and a force in the X-axis direction is applied to the main body 5, vibration of the tip terminal 3 including the cutting tool 2 is suppressed. Therefore, a reduction in processing accuracy is suppressed.

  Further, according to the present embodiment, the latch housing 162 is rotated around the central axis AXh while the inner surface of the latch housing 162 and the cutting tool 2 are in contact with each other, and the large diameter portion 162A and the small diameter portion 162B of the latch housing 162 are In machining the inner surface of the fitting portion 40 including the boundary portion 162C, the tool 1 is moved in the Z-axis direction. Thereby, in the state where generation | occurrence | production of the vibration of the front terminal 3 was suppressed, the process of the boundary part 162C can be performed accurately. Further, in processing, interference between the latch housing 162 and the main body 5 is suppressed.

  Moreover, according to this embodiment, the 1st external shape of the base end part 8 is an ellipse. Thereby, the main-body part 5 with high rigidity can be manufactured smoothly.

  Further, according to the present embodiment, the outer shape of at least a part of the intermediate portion 9 is elliptical in the XZ plane. Thereby, the main-body part 5 with high rigidity can be manufactured smoothly.

  Further, according to the present embodiment, the second dimension D2 and the fourth dimension D4 are equal, and the first dimension D1 is larger than the third dimension D3. Thereby, the main-body part 5 with high rigidity can be obtained, suppressing the enlargement of the main-body part 5 of a Z-axis direction.

  Further, according to the present embodiment, the third dimension D3 and the fourth dimension D4 are equal. Thereby, the diameter increase of the front-end | tip part 7 is suppressed.

  Moreover, according to this embodiment, the 2nd external shape of the front-end | tip part 7 is a perfect circle. Thereby, the main body part 5 having high rigidity can be smoothly manufactured while suppressing an increase in the diameter of the distal end part 7.

  Further, according to the present embodiment, the tool 1 is inserted into the internal space of the latch housing 162 from the second opening 172 disposed at the end of the small diameter portion 162B, and protrudes in the Z-axis direction from the outer surface of the main body portion 5. The tool 1 moves in the Z-axis direction while rotating the latch housing 162 by bringing the cutting tool 2 and the inner surface of the latch housing 162 into contact with each other. Thereby, the inner surface of the latch housing 162 can be machined while suppressing a decrease in machining accuracy using a tool in which at least lack of rigidity in the X-axis direction is suppressed. Moreover, the operation | movement which inserts the tool 1 in the interior space of the latch housing 162 from the small diameter part 162B side is performed smoothly.

  Further, according to the present embodiment, the latch housing 162 is provided in the nuclear reactor 100 and houses the latch mechanism 146 that intermittently holds the control rod drive shaft 140 that moves in the vertical direction. At least one of the boundary portion 162C and a part of the large diameter portion 162A adjacent to the boundary portion 162C includes a fitting portion 40 that holds the latch mechanism 146. The fitting portion 40 is required to have high processing accuracy. Using the tool 1, the inner surface of the fitting portion 40 can be processed with high processing accuracy.

1 Tool 2 Bite (blade)
3 Lead terminal 4 Shaft member 5 Body portion 6 Fixed portion 7 Tip portion 8 Base end portion 9 Intermediate portion 10 Fixing member 20 Rotating device 30 Fixing device 40 Fitting portion 100 Reactor 101 Reactor vessel 102 Reactor vessel body 103 Atom Reactor vessel lid 104 Inlet nozzle 105 Outlet nozzle 110 Core core 111 Upper core plate 112 Lower core plate 113 Upper core support plate 114 Core support rod 115 Radial key 120 Core 121 Fuel assembly 122 Control rod 123 Control rod cluster 124 Control rod cluster guide Pipe 125 Control rod drive unit 131 Upper plenum 132 Lower plenum 133 Downcommer portion 140 Control rod drive shaft 140a Circumferential groove 141 Fixed grip latch support tube 142 Fixed grip latch 143 Fixed grip latch link 144 Fixed grip plunger 145 Fixed grip coil 146 Hatch mechanism 147 Movable gripper latch 148 Movable gripper latch link 149 Movable gripper plunger 150 Movable gripper coil 151 Lifting coil 152 Drive mechanism 153 Fixed gripping magnetic pole
154 Movable gripping magnetic pole 155 Raising magnetic pole 156A Return spring 156B Return spring 156C Return spring 160 Control rod drive device housing 161 Drive shaft guide tube 162 Latch housing 162A Large diameter portion 162B Small diameter portion 162C Boundary portion 163 Cap 164 Base 165 Coil housing 171 1 opening 172 2nd opening AXb center axis AXh center axis D1 1st dimension D2 2nd dimension D3 3rd dimension D4 4th dimension D5 5th dimension D6 6th dimension L1 1st length L2 2nd length L3 3rd length The

Claims (10)

A tool for machining the inner surface of a cylindrical member,
A tip containing a byte, and
A shaft member to which the tip terminal is connected;
With
The shaft member is
A main body having a tip to which the tip terminal is connected;
A fixed portion that is disposed at a base end portion of the main body portion and is fixed to a lathe fixing device;
In a plane orthogonal to the central axis of the shaft member, the base end portion has a first outer shape with a curved first contour, and the distal end portion has a second outer shape with a curved second contour;
A first dimension indicating the first outer shape in a direction parallel to the first axis in the plane is a second dimension indicating the first outer shape in a direction parallel to the second axis in the plane orthogonal to the first axis. Larger than the dimensions,
The second dimension is larger than a third dimension indicating the second outer shape in a direction parallel to the first axis and a fourth dimension indicating the second outer shape in a direction parallel to the second axis, or Equal to the fourth dimension,
The outer surface of the intermediate portion of the main body portion between the distal end portion and the base end portion includes a curved surface connecting the first contour and the second contour.
tool. The cutting tool is disposed so as to protrude from the outer surface of the main body in a direction parallel to the second axis.
The tool according to claim 1. With the inner surface of the cylindrical member and the cutting tool in contact with each other, the cylindrical member is rotated,
In the processing of the inner surface of the boundary portion between the large diameter portion and the small diameter portion of the cylindrical member, the cylindrical member is moved in a direction parallel to the second axis.
The tool according to claim 2. The first outer shape is elliptical.
The tool according to any one of claims 1 to 3. In the plane, the outer shape of at least a part of the intermediate portion is oval.
The tool according to claim 3. The second dimension and the fourth dimension are equal,
The first dimension is greater than the third dimension;
The tool according to claim 4 or 5. The third dimension and the fourth dimension are equal,
The tool according to any one of claims 4 to 6. The second outer shape is a perfect circle.
The tool according to claim 7. A processing method for processing the inner surface of a cylindrical member,
The cylindrical member includes a large-diameter portion having a first length, and a small-diameter portion having a second length that is connected to the large-diameter portion via a boundary portion and shorter than the first length.
Inserting the tool according to claim 1 into an internal space of the cylindrical member from an opening disposed at an end of the small diameter portion;
Contacting the inner surface of the tubular member with the bite arranged so as to protrude from the outer surface of the main body in a direction parallel to the second axis;
Moving the tool in a direction parallel to the second axis while rotating the tubular member;
including,
Processing method. The cylindrical member includes a latch housing that is provided in the nuclear reactor and accommodates a latch mechanism that intermittently holds a control rod drive shaft that moves in the vertical direction.
At least one of the boundary portion and a portion of the large diameter portion adjacent to the boundary portion includes a fitting portion that holds the latch mechanism,
Using the tool, machining the inner surface of the boundary portion and the inner surface of the portion of the large diameter portion,
The processing method according to claim 9.

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